Section 3 - Installation & Maintenance
Contents
1. N at QU CU ek o 5 Qo z v 5 ot D 2 D 5 A M Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance 1 2 2 Backlash In high ratio gearing the larger of the two mating gears usually has its teeth thinned to accommodate this and the smaller one is kept at nominal to maximize its tooth strength The amount of tooth thinning or backlash allowance is Shown on Kaydon s drawings which may be obtained by contacting Kaydon Typical backlash ranges are shown in Table 3 14 For module gears use the approximate equivalent gear pitch diameter and diametral pitch as shown in the table Backlash is required for most geared slewing ring bearing applications This is to accommodate manufacturing tolerances of the gears mounting structures lubrication thermal expansion and deflection of the components under dynamic loading Refer to Figure 3 13 The backlash should be measured just inside each end of the pinion and gear mesh to verify that proper alignment is obtained Poor alignment can result in premature tooth wear and breakage Consider any crowning of the pinion teeth when evaluating the alignment D U c o cc D Pas E 49 o l9 O ns JL 2 m 25 4 module Pa The designer or manufacturer needs to determine whether to use a fixed or adjustable center distance Factors that influence this decision are skill level of assemblers installa2. Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Section 3 Installation amp Maintenance The following instructions provide essential information Technical properties of slewing ring bearings are covered for the proper application installation and maintenance in Sections 2 and 4 of Kaydon 390 Catalog of Kaydon slewing ring bearings These instructions are divided into sections according to each of these disciplines and must be performed by qualified A personnel Kaydon accepts no liability for 1 Non compliance to instructions provided in this A Failure to adhere to these instructions may Installation and Maintenance literature significantly impair the slewing ring bearing s ability to provide satisfactory service and may cause premature failure of the bearing as well as endanger safety of any personnel in the vicinity of the equipment 2 Failure to pass on content to third party 3 i at S ct o QO at D CD 5 N MD 1 800 514 3066 www kaydonbearings com ES Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Section 3 Contents Installation amp Maintenance Page Number Part 1 Design Considerations For Equipment Designer 25 1 1 Mounting Structure 1 1 1 Stiffness 1 1 2 Interface Features 1 1 2 1 Flatness 1 1 2 2 Pilots 1 1 2 3 Holes 1 1 3 Protection 1 1 4 Access For Installation and Maintenance 1 1
3. FS www kaydonbearings com 1 800 514 3066 2 3 Installation Itisimportant to recognize the vital role of the bearing gear and the means for securing it to the equipment whether it be with bolts or welds Detailed and clear instructions need to be prepared for the installer When bolts are used as the means of attachment tests need to be conducted to validate that the method of bolt pretensioning achieves the desired results Confirm the bolts have the proper quality standard and manufacturer identification as prescribed by the designer If the bearing is to be attached by welding conduct the necessary tests to prove that the specified joint will be strong enough to safely attach to the bearing Examine for and remove weld spatters nicks and burrs If surfaces have been painted remove the paint completely 2 3 1 Preparation Installation of the bearing and gear assembly should be done in a clean dry well lit area Mounting surfaces and pilots of the housings should be machined and wiped clean of paint chips dirt and lint Even soft material trapped between the mounting and bearing surfaces can result in high spots and affect bearing and bolt performance When this has been done examine for and remove weld spatter paint nicks and burrs and wipe clean again The mounting faces need to be machined and in accordance with the limits prescribed in Part 1 Paragraph 1 1 2 Confirm that the bearing and all necessary and corr
4. Mounting Structure Deviations 6 4 circumferential deflection radial deflection 6 circumferential flatness radial dish perpendicularity Figure 3 3 PN Kaydon offers the following guidelines to assist ll Obtaining a uniform distribution ofthe load to the designers Failure to follow any of these may cause additional risk and or premature failure Therefore testing of the overall configuration and bearing installation is required to validate the design Extra caution is required during any testing as failure of any component could lead to complete separation This may result in injury or fatality to anyone in close proximity I I A uniform vertical and tube shaped structure with a flange on one end should be used allowing adequate room for fastener installation and maintenance This structure would be similar to the end of a flanged pipe with a diameter close to that of the bearing s raceway Refer to Figure 3 5 For initial sizing wall thickness of such tubing should be at least 1 5 the overall height of p the adjacent bearing s ring Refer to Figure 3 4 E The mounting or structural plate supporting the bearing should have a finished thickness of 1 2 of the bearing ring height for single row rolling element bearings and at least 1 3 of the bearing ring height for multi row bearings Generally thinner mounting plates require more structural support and bracing to stiffen the overall design The final thickness of pl
5. N MD Apply a moderate centered thrust load to the bearing and note the torque required to rotate the bearing A Tighten all bolts in accordance with the equipment designer s instructions Failure to follow the equipment designer s instructions could result in premature wear or catastrophic failure of the bearing and result in damage to equipment personal injury or death A common method is the use of star pattern tightening following the sequence below This is usually done in 3 steps at approximately 30 80 and 100 of the final torque or tension level prescribed by the equipment designer Figure 3 19 1 800 514 3066 www kaydonbearings com ES D U c o cc D Pas E 49 o a l9 Em O ns 2 Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance Rotate the unsecured bearing ring several times after each step checking for tight spots or a significant increase in torque over that initially noted Either of these indicates the bearing is distorted Determine and correct the cause Remove the centered thrust load previously applied to the bearing and prior to securing the other ring Position the other bearing support structure on the unsecured bearing ring This support structure should have minimal number of components attached to keep weight and moment load low so the bolt tensioning operation is not adversely affe
6. failure or poor bearing performance The operator should be very familiar with the typical operating conditions generated by the equipment Investigate and resolve any noted changes 2 5 6 Torque Monitoring rotational torque and any variation can not only be used to determine a bearing s condition but can also provide early indication to a gear joint or other structural problem To determine any change in torque it is first 1 800 514 3066 www kaydonbearings com N at QU CU ek o 5 Qo z v 5 ot D 2 D 5 A M D 9 rem o c D amp o c oO p EU n JL 2 s Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance necessary to record an initial measurement best done after testing and prior to the equipment going into service Check torque every 700 hours of operation or every 12 months whichever occurs first and resolve the cause for any changes 2 5 7 Tilt Clearance Internal bearing clearance will increase with raceway and rolling element wear The rate of wear along with other key bearing performance criteria will enable the end user to monitor and determine the condition of the bearing and anticipate when replacement is required A measurement of the bearing s axial movement tilt is a reliable indicator of the bearing s internal clearance To determine the amount of wear that has occurred it is necessary to perform an in
7. 5 Attachment 1 1 5 1 Bolts 1 1 5 2 Welding 1 2 Pinion and Gear Mesh 1 2 1 Pinion Design Considerations 1 2 2 Backlash 1 3 Mounting Examples D U c o cc D Pas E 49 o Cc l9 O ns JL 2 Part 2 Installation and Maintenance For Equipment Builder 38 24 Handling 2 2 Storage 2 3 Installation 2 3 1 Preparation 2 32 Positioning 2 3 3 Securing 2 3 4 Gear Backlash and Alignment 24 Post Installation 2 5 Maintenance 2 5 1 Lubrication 2 5 1 1 Bearing 2 5 1 2 Gear 2 5 2 Bolts 2 5 3 Seals 2 5 4 Cleaning 2 5 5 Noise Roughness Vibration 2 5 6 Torque 2 5 7 Tilt Clearance 2 5 8 Dismantling and Disposal Part 3 Maintenance Guidance for Equipment Owner and or User 44 3 1 Before Use 3 2 During Use 3 3 Grease Lubricants Table PS www kaydonbearings com 1 800 514 3066 Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance 1 Design Considerations Guidance for the Equipment Designer Slewing ring bearings due to the nature of their design have low structural stiffness making them highly susceptible to any distortions caused by the surrounding structures Such distortions cause variations to the precisely designed and manufactured internal geometry of the bearing and will adversely affect performance and life 1 1 Mounting Structure Most component designs are a necessary compromis
8. an exposed diameter of one ring or as close as possible so that it will record relative axial movement between the bearing rings Accuracy of the dial indicator must be 0 001 or finer Refer to Figure 3 21 B Set the dial indicator to zero I Prepare to note movement and final reading of indicator during following step E Without rotating the bearing ring apply force on the rotating structure and components in a manner so it causes a complete reversal of the moment load on the bearing B Record the final dial indicator reading E Remove the recently applied force permitting the original moment load to exist on the bearing E The dial indicator should return to zero If it does not identify and correct the cause E Remove the dial indicator and align the permanent mark on the rotating structure with one of the three marks previously put on the stationary structure E Use the same procedure to record measurements at this and the remaining two locations E Record these readings in a service manual or other secure document for future reference I Compare individual readings to the initial measurements recorded at the same relative location The increase in tilt is the maximum difference observed Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance TABLE 3 22 ALLOWABLE TILT INCREASE in Rolling Element z Diameter Style 3 D zi d O gt i Qo in in 0 6
9. is required for your bearing Kaydon is available to provide assistance to help you select a mounting hole pattern for the bearing in question The following is a list of additional recommendations concerning bolts and their incorporation into the final equipment design The items listed below are not all inclusive and further study on the subject is recommended These recommendations are intended to provide the designer with a good basis from which to begin E High strength bolts with coarse threads and hexagon heads in accordance with SAE J429 Grade 8 or ASTM A490 A490M or ISO 898 1 Grade 10 9 tensioned to 7096 of their yield strength D 9 rem o c D amp o o c oO p EU n JL 2 s 8 Where applicable coarse threaded hex head nuts in accordance with SAE J995 Grade 8 or ASTM A563 Grade DH or ISO 898 2 Class 10 8 Hardened round flat steel washers in accordance with ASTM F436 under head of bolt and also nut E Use of hardware that identifies the manufacturer as well as proper SAE ASTM or ISO grade designations B The ratio of the joint s clamp length distance from the bottom of the bolt head to the first thread of engagement to the nominal bolt diameter should equal 3 5 or greater This ratio has a significant impact on embedment and the potential for loss of bolt tension and premature failure A higher ratio is less prone to result in loss of bolt tension Lower ratios may prove unacceptable
10. pin See Figure 3 10 ES www kaydonbearings com 1 800 514 3066 Access holes for loading plug Figure 3 10 1 1 5 Attachment The method of attachment of Kaydon bearings to the support structure significantly affects its design The preferred method is to use bolts in both rings If you require assistance with applications where the attachment for one ring is to be done by welding contact Kaydon 1 1 5 1 Bolts The preferred bolting arrangement is a full circle of uniformly spaced fasteners going through holes in both bearing races This benefits both the bearing and the bolts The bearing races are reinforced by the bolt tension The resulting greater bolt grip length allows more accurate and uniform pretension reducing fatique loading However it is not always practical to have all the mounting holes spaced exactly equal on all designs due to interference with supporting structures or brackets In such cases the spacing between adjacent bolts may be shifted a few degrees either way to accommodate mounting hardware and assembly Testing is recommended as it is the only accurate method for determining bolt loads and validation of the overall joint configuration and assembly procedure Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance A The bolt arrangement quantity size and thread engagement of bolts are the responsibility of the equipment designer and manufacturer for th
11. 25 0 030 0 010 z 0 0 750 0 035 0 012 s A 0 875 0 040 0 013 E 1 000 0 045 0 016 Tilt Measurement Position 1 125 0 050 0 018 Figure 3 21 1 250 0 055 0 020 The increase in tilt is the difference in the last reading taken me mT and the initial reading taken prior to the equipment 1 500 0 065 0 024 beginning service The maximum permissible increase in tilt is shown in Table 3 22 according to rolling element type 1 750 0 075 0 028 and diameter Replace the bearing when the difference 2 000 0 080 0 032 exceeds the values shown in Table 3 22 Contact Kaydon should there be additional questions dee sid es 2 500 0 100 0 040 2 5 8 Dismantling and Disposal 2 750 0110 _ Should it be necessary to remove the bearing from the 3 000 0 115 equipment proceed in reverse order of that used for installation or as close as safely possible USED EIOS OHIONRO Ciera Contact a Kaydon representative concerning potential for repair or replacement Disposal shall be in accordance with environmental and other local regulations applicable to the materials used 1 800 514 3066 www kaydonbearings com Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance 3 Maintenance Guidance for Equipment Owner and or User Slewing ring bearings require routine maintenance to ensure optimum performance and that the life determined by the equipment designer is achieved It is important to follow the service and
12. P Where P radial distance of mounting structure face The allowable degree of out of flatness for roller bearings is 2 3 the limit for an equivalent sized four point ball bearing It may be necessary to reduce the 6 and 9 values in applications which require low rotational resistance or high precision Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance Allowable Flatness vs Raceway Diameter Must not occur within 90 nor more than once in 180 of circumferential travel 040 035 o 030 2 5S 025 VU e 020 VU 5 x 015 E 010 1 0 Ball 5 Ball 000 3 0 Ball 2 5 Ball 2 0 Ball N at QU CU gt o 3 Qo z v 5 ot D 2 D 5 A M 1 5 Ball O 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 Raceway Diameter D in Figure 3 9 Kaydon does not recommend the use of grout or shims to compensate for excessive out of flatness 1 1 2 2 Pilots Pilots are sometimes used for accurate location of the bearing or to aid in retention ofthe bearing If used they must be round and accurately sized so that they do not distort the bearing Consideration must also be given to their eccentricity and positioning tolerance relative to any hole patterns used in the structure and the interfacing bearing ring Kaydon can provide the applicable bearing assembly drawing which
13. aces located near bolt mounting holes increases side plate and mounting plate rigidity and provides additional load distribution around bolt pattern and bearing 1 800 514 3066 www kaydonbearings com Un at CU ct o 3 Qo z z at D 5 D A MD D 9 o D amp o o c oO p EU n JL 2 s Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance T I wA VL LLL A DK Welded Plates Potential for Detrimental Distortion Figure 3 8 1 1 2 Interface Features 1 1 2 1 Flatness Bearing mounting surfaces must be machined flat after all welding and stress relief treatment on the structures is complete If subsequent welding is necessary it must be done to avoid distorting the previously machined mounting surface The allowable degree of out of flatness in the circumferential direction 6 for typical four point and eight point ball bearings is shown in Figure 3 9 Out of flatness like distortion must be gradual reflecting a sinusodial wave pattern and not occur in a span less than 90 and not more than once in 180 FS www kaydonbearings com 1 800 514 3066 In addition to flatness in the circumferential direction the allowable dish or perpendicularity deviation 6 n in the radial direction must be determined For ball bearing designs this can be done using the following equation 0 001 Dy
14. and require more frequent inspection of the bolts for proper tension Testing is required for validation ll Bolts threads should end short of the head by at least a distance equivalent to the body diameter I Equal clamp or grip length for all mounting bolts in a given ring www kaydonbearings com 1 800 514 3066 I The thread engagement length between bolt and mating steel structure should be at least 1 25 times the nominal bolt diameter I A bolt should be used in every mounting hole I There should be a minimum of 6 free threads not engaged in the tensioned portion of the bolt I Performance of bench tests is recommended to validate that the method of bolt tensioning achieves the desired results prior to any equipment testing High strength socket head bolts ASTM A574 are not preferred but have been successfully used in slewing ring bearing applications These high strength bolts have a smaller head diameter which requires less space however they also have less surface area under the head This reduced surface area increases the potential for more variation in final bolt tension due to embedding and settling High strength socket head bolts must be used in conjunction with a hardened washer and nut The nut should be turned to achieve final bolt tension If possible use a hardened washer under the head as well as with the nut to minimize embedment settling and loss of bolt tension that could result in premature bolt fail
15. ate required i will vary depending on the overall configuration of the structure and load being applied Testing as mentioned above is recommended E The face of the structure that supports the bearing must make contact with the complete mounting face of the bearing s ring and have surface finish 250 AA or better bearing is difficult when using a frame welded structure and gussets for structural support under the mating plate Should it be necessary to use such a design the frame and supporting structure must be oriented to provide as much support as possible directly below the bearing s raceway Refer to Figures 3 6 and 3 7 If the immediate structure supporting the bearing consists of two plates one welded atop the other caution must be taken to avoid distortion of the plates during welding as it could result in undetected voids between them Under load the plates will deflect causing non uniform and increased dynamic loads on the bearing and retaining bolts Refer to Figure 3 8 Variation in the physical grip length of the bearing s mounting bolts is not permissible in the design of the mounting structure The physical grip length is the distance from the bottom of the bolt head to the first thread of engagement Such variation imposes a disproportionate amount of load on those having shorter grip length This can lead to premature failure and or separation of the assembly Special attention needs to be given to stiffness
16. cted Align mounting holes and orient the ring so the load plug and or hardening gap location identified by a G is 90 from the most heavily loaded zone Using a gauge verify the bearing fully supports the mating structure If not then determine cause and correct Insert and tighten bolts in second ring as done for secured ring Continue to rotate and check bearing for tight or excessive torque during this operation Complete installation of all rotating components of significant weight and check bearing for freedom of rotation Excessive torque level variation or vibration is indicative of some unsatisfactory installation condition or component As permitted inspect seals again for any damage 2 3 4 Gear Backlash and Alignment After mounting the bearing mount the mating pinion Check backlash of the gears Pinions on adjustable centers should be set for proper backlash Do this at point of minimum backlash on the gear identified with yellow paint in the tooth space and at both ends to confirm prescribed alignment exists If either of these is not as prescribed by the designer determine and correct the cause Refer to Figure 3 20 Ps www kaydonbearings com 1 800 514 3066 Gear Backlash Figure 3 20 2 4 Post Installation When the equipment has been completely assembled and prior to testing check bolt tension to ensure that it is in compliance with that specified by the designer The equipment should be or
17. der all potential operating circumstances which could be detrimental to pinion and gear life A pinion supported only on one end is often selected for mating with slewing ring bearings This is commonly referred to as an overhung pinion Use ofthis type of arrangement whenever high gear tooth loads exist requires the designer to consider pinion modifications not commonly used with standard gear transmissions We suggest that the following gear design modifications should be considered when selecting a mating pinion i Addendum modification profile shift This is especially important for pinions having fewer than 15 teeth for a Stub Involute tooth form and 19 teeth for a Full Depth Involute tooth form to avoid undercut weakened tooth design and to avoid tip or involute interference I Profile and tip relief Refer to Figures 3 11 amp 3 12 Higher dynamic loads fewer pinion teeth and support only on one end ofthe pinion increase potential for deflection of the gear and pinion teeth during its width This is considered a good practice for highly loaded gears as it allows better distribution of the stresses along the tooth face For situations with over hung pinion mounting off setting the crown should be considered to account for pinion and drive deflections and provide a more even stress distribution Generally the thickest section along the tooth face is off centered toward the unsupported end of the pinion I Surface harde
18. e from the ideal to the practical The design of mounting structures for large multiload bearings is no exception Regardless several criteria must be satisfied by the mounting structures above and below the bearing in order to obtain maximum bearing life and performance Among these are stiffness attachment precision accuracy protection and access The requirement for increased stiffness and higher precision surfaces is more critical under the following conditions I Increasing loads I Increased frequency of operation i Decreasing diameters I Decreasing bearing cross sections I Decreasing internal bearing clearance I Decreasing torque limits Protection of the bearing and accessibility for maintenance are critical to ensure bearing performance and longevity The following guidelines make reference to the bearing s rolling element diameter D and raceway diameter D During initial stages the designer can use the following approximations As required contact Kaydon for the specific bearing assembly drawing for confirmation of the raceway diameter and other important design features D 0 5 H nin D 0 5 Ly L Kaydon recommends steel to fabricate any structures used in conjunction with its slewing ring bearings unless otherwise specified The actual steel material selected will vary as required by the final structure design and resulting stresses The use of higher strength steels does not necessarily result in incr
19. e following reasons E There is no universally accepted method of analyzing the forces imposed on the bolts in a slewing ring bearing joint subjected to moment loading I The stiffness uniformity and final design of the structures to which the bearing is attached have an extremely high degree of influence on the load in the fasteners Only the equipment designer or manufacturer can control this E The quality of the fastening hardware method of tensioning hardness of the surfaces under the bolt heads and the use of thread lubricant are critical factors over which the equipment manufacturer has control We suggest that selection of the bolts should be made with the advice and assistance of the fastening hardware supplier as bolt quality and recommended method of pretensioning and maintenance vary widely Attention to details such as head body fillet radius thread form finish surface asperities and freedom from cracks and other possibly fatal flaws are very important to the safety of the equipment and any personnel in the vicinity The importance of adequate and uniform pretensioning is evident from the proliferation and technological advancement of devices such as B Turn of the nut indicators I Preload indicating washers E Torque wrenches with integral yield sensors E Hydraulic bolt stretchers E Ultrasonic measuring equipment I Toaid the designer in initial sizing the following formula can be used to calculate the app
20. eased stiffness The choice of material for the structure is the equipment designer s or manufacturer s 1 1 1 Stiffness The ideal bearing mounting would be infinitely rigid and isolate the bearing from localized loads and distortion Recognizing this to be impractical while still maintaining the original equipment design goals Kaydon prepared Figures 3 1 to 3 3 Deflection showing maximum permissible deflections that typical four point and eight point ball bearings can withstand while maintaining correct function Allowable circumferential deflection 6 around the structure s mounting face is shown in Figure 3 1 There must be no abrupt changes in deflection The maximum deflection error must be gradual similar to a sinusodal wave pattern and not occur in a span less than 90 and not more than once in 180 Another consideration is the allowable deflection from a true plane in a radial direction 6 also referred to as dish or perpendicularity For ball bearing designs this can be determined by using the following equation 6 0 003 D P Where P radial distance of mounting structure face The maximum circumferential and radial deflection for roller bearing designs is 2 3 of that for the equivalent sized four point ball bearing Reduction of the 6 and 6 values may be necessary due to certain application requirements such as lower rotational resistance or higher precision A Equipment designs not complying to th
21. ect hardware are on site before beginning the installation Verify the bolts and mounting hardware are of the size design finish and quality specified by the designer The bolts must have proper identification for the quality standard required Using bolts that are not in conformance with those prescribed can lead to unsatisfactory bearing performance premature failure and a potentially fatal working environment Refer to Part 1 Paragraph 1 1 5 1 Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance 2 3 2 Positioning If one ring has a pilot or dowel hole it should be positioned and mounted first Consider alignment of gear s minimum backlash on structure so any necessary adjustments can be made Identify zones of maximum load on supporting structures to which the bearing will be secured When in doubt consult with the equipment designer for their instructions Examine and identify any damage to packaging prior to unwrapping the bearing then it should be wiped clean and inspected Do not expose the seal area or any other bearing opening to pressurized cleaning Use only cleaning material that is compatible with the seal material and avoid getting debris or other material into the bearing Visually inspect and confirm that there is no damage to the bearing gear seals or grease fittings Remove any minor burrs from mounting surfaces that may have occurred in shipping or handl
22. ese requirements will adversely affect bearing performance imposing concentrated loads on the bearing and adjoining fasteners Concentration of loads results in higher loads on the rolling elements raceways and adjoining fasteners This will lead to increased rotational resistance decreased bearing and fastener life and a potentially unsafe working environment 1 800 514 3066 www kaydonbearings com ET N at QU CU ek o 5 Qo z v 5 ot D 2 D 5 A M Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance Allowable Deflection vs Raceway Diameter Must not occur within 90 nor more than once in 180 of circumferential travel 120 Y 110 3 0 Ball e 100 g i 090 O p 1 080 2 5 Ball gt 5 070 S c c 2 060 U 2 0 Ball i e 050 e E 040 1 5 Ball 030 o lt 020 1 0 Ball 010 ee Bal O 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 000 Raceway Diameter D in Figure 3 1 Permissible Deviation Rate r eo dis Max Value c o eo c 9 dud S E Permissible E Curve 2 b qQ a 0 Circumferential Direction 180 Deg Figure 3 2 PS www kaydonbearings com 1 800 514 3066 Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance Circumferential Radial 9 and 6 and 0 1 Radial Distance P and 5
23. iented to generate as little moment or radial load on the bearing as possible to avoid inaccuracy in readings Document this orientation so it may be used for all future bolt inspections Any loss of pretensioning must be determined and eliminated Measure and record initial bearing tilt Clearance of equipment following guideline provided in Paragraph 2 5 7 During and after validation testing check bolt tension with equipment orientation as previously done and documented Any loss of pretensioning must be determined and eliminated Follow Paragraph 2 5 1 for lubrication intervals of bearing and gear during testing Relubricate the bearing and gear prior to delivery of the machine Introduce fresh grease into the bearing until grease is observed coming from under either seal Rotate the bearing several times to ensure a complete fill Repeat every 6 months on idle equipment or as recommended by the equipment designer Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance 2 5 Maintenance While Kaydon slewing ring bearings require minimal attention what little they are given will pay big dividends in long life high performance and trouble free service 2 5 1 Lubrication 2 5 1 1 Bearing Lubrication of the bearing is recommended every 100 operating hours for relatively slow rotating or oscillating applications such as backhoes excavators and cranes or as specified by the designe
24. includes interfacing tolerances 1 1 2 3 Holes Mounting holes and dowel holes if any must be within the true location tolerances required to prevent distortion of the bearing due to interference Mounting hole location tolerance must account for eccentricity of the hole pattern relative to any pilot diameters Through holes should be compatible with the location tolerance and of a diameter equivalent to those in the corresponding bearing ring Kaydon can provide the applicable bearing assembly drawing which includes interface features and tolerances Bearings should never be used as drill jigs They may be used as templates for transfer of hole location provided care is taken not to distort the bearing Distortion is more likely to occur on bearings having thinner ring sections 1 1 3 Protection Kaydon bearings are designed to withstand normal operating environments If the upper structure does not provide complete cover for the bearing a separate seal or shield is recommended Exposed gears should be shrouded if they are to be exposed to extremely dirty conditions Shields and shrouds should be designed with cover doors plugs or other means of access to the bearing for maintenance purposes To further enhance protection Kaydon can provide painting or plating options as required 1 800 514 3066 www kaydonbearings com ES D 9 rem o c D amp o c oO p EU n JL 2 s Slewing Ring Bearing
25. ing Use a hand file taking care to remove only as much material as necessary to ensure full contact of bearing surface with equipment mounting surface Make sure all surfaces are wiped clean We recommend that the bearing not be disassembled without express approval of and instruction from Kaydon Removal of the loading hole plug voids the warranty Lift or hoist the bearing into position placing intended ring down on its supporting structure Align the mounting holes and orient the ring so the load plug and or hardening gap location identified by a G is 90 from the most heavily loaded zone Confirm the grease fittings or holes are located for easy access or aligned with lubrication lines Using a gauge verify the bearing is fully supported by the mounting structure If not then determine cause and correct 2 3 3 Securing For good load distribution and smooth low torque operation the bearing should be as round as possible when the bolts are tightened The following procedure is provided as an aid in achieving that objective Install washers nuts and hand tighten bolts in the supported ring according to the instructions from designer Make sure there is no interference or rubbing of the bolts in any ofthe holes Do not distort the bearing in order to insert any bolts Interference can cause inaccurate results and lead to premature failure of bearing and bolts 3 i at CU ct o 5 Qo ot D 5 Q 5
26. itial tilt measurement before the equipment is put into service Continued measurement of tilt following the same documented procedure is required to assist the equipment user in determining when a bearing requires removal Tilt measurements should be taken every 700 hours of operation or every 12 months whichever occurs first Whenever the increase in tilt reaches 7596 of that shown in Table 322 reduce the frequency of measurement to 300 hours As the rate of wear increases the period between measurements should decrease accordingly The following information is an outline for determining a bearings tilt In order to perform the tilt measurement it is necessary to subject the bearing to a complete moment load reversal removing all clearance from one side but not exceeding 2596 of maximum equipment rating Contact Kaydon to discuss any alternative inspections Bl Orient the equipment so the bearing is subject to a moment load i Permanently mark the point where the dial indicator is to be positioned for measurement on the rotating and stationary structure This should be in line with the main load or moment load www kaydonbearings com 1 800 514 3066 E Without rotation of equipment permanently mark three additional points on the stationary structure where future measurements will be taken These should be at locations resulting in four total points all spaced 90 apart E Attach a dial indicator at the initial point to
27. les omission of integral gears and incorporation of special seals 3 i at CU ct o 5 Qo at D CD 5 N MD Ill o I Ss Figure 3 15 Figure 3 17 Pinion is attached to stationary outer race support and rotates the upper Pinion is attached to rotating upper structure carried by outer race structure supported by the inner race A shroud over the outer seal and Location of gear on inner ring provides protection from harsh external bolts prevents contamination under extreme conditions conditions Figure 3 16 Figure 3 18 Inner race supports the rotating upper structure with pinion An external Pinion is attached to stationary inner race and rotates geared outer race shroud protects the gear teeth on the stationary outer race carrying upper structure 1 800 514 3066 www kaydonbearings com D 9 rem o c D amp o c oO p EU n JL 2 s Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance 2 Installation and Maintenance Considerations Guidance for the Equipment Builder 2 1 Handling Slewing ring bearings like any other machine part require careful handling Use of safe operating practices and Observation of all relevant legal regulations when handling cleaning and transporting are required It is recommended that gloves be used whenever handling the bearing Transport the bearings only in the horizontal
28. maintenance recommendations contained in the equipment manufacturer s instruction manual 3 1 Before Use If there is no assurance that the bearing gear has been lubricated within the past six months or after 100 hours of operation introduce fresh grease according to the equipment manufacturer s instruction manual D U c o cc D Pas E 49 o a l9 Em O ns 2 3 2 During Use E Relubricate bearing and gear according to directions in the equipment manufacturer s instructions I Inspect seals making certain that they are in proper position in grooves and intact A ll Verify tension of all mounting bolts is in accordance with Owner s Manual A I Be alert to changes in torque unusual sounds and or vibrations 3 3 Grease Lubricants For Slewing Ring Slewing Ring Bearings and Their Open Gears Selection of the lubricants used in a slewing ring bearing and the integral open gear is dependent on the application The designer of the equipment is responsible for selecting an appropriate lubricant and should consult a tribologist for assistance in selecting lubricants for use in the design Some of the more commonly used lubricants are shown in table below These have been used in Kaydon slewing ring bearings when operated in NORMAL applications Refer to Section 2 of this catalog for further explanation The list contains commercially available greases from major lubricant manufacturers The l
29. ning of the pinion The pinion experiences more operating cycles than the gear teeth Therefore it requires a higher surface endurance life This is accomplished by through hardening or selective hardening When through hardening care must be taken to prevent the pinion teeth from becoming too hard and brittle for the intended application and mating gear Selective hardening of the pinion is an alternative when surface hardness and ductility are major design concerns A hardness pattern that ends in the fillet area has significantly less strength than one that flows completely around the fillet and up both flanks The heat treat methods to accomplish this include carburizing nitriding or induction hardening In all cases evaluation of the hardness pattern including the transition area is necessary to determine if it is appropriate for the intended use i Quality The pinion quality should be equivalent to or better than that of the mating gear operation These conditions have a tendency to b Y generate wear scuffing in the dedendum of the gear TT tooth regardless of the teeth having correct profiles and theoretically compatible geometry Scuffing _ generates metallic wear particles and weakens the gear tooth This may prove detrimental to gear and pinion Scuffing on Flank Tip and life depending on the operating circumstances Dedendum Profile Relief Figure 3 11 Figure 3 12 1 800 514 3066 www kaydonbearings com ES
30. of the gear drive mounting area Designs having insufficient rigidity in this area will permit deflection and result in poor gear and pinion mesh alignment Poor alignment can lead to premature failure of the pinion gear and gear drive 1 800 514 3066 www kaydonbearings com 3 i at CU ct o 5 Qo ot D 5 Q 5 a MD Slewing Ring Bearings Catalog 390 OKaydon Corporation Issue 1 Installation amp Maintenance D i9 c o c D E 49 o Cc l9 O ns 2 Minimum Mounting Support Requirements Figure 3 4 Vertical Tube with Flange for Mounting Support Figure 3 5 FS www kaydonbearings com 1 800 514 3066 Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance BEARING MOUNTING PLATE Frame without gussets near mounting Gussets added near bearing mounting holes holes requires thicker plate increase rigidity Fabricated Frame amp Structure Supports Figure 3 6 Turnstile without braces lowers side Turnstile with braces increases side plate plate and mounting plate rigidity and mounting plate rigidity and provides reducing load distribution around bolt increased load distribution around bolt pattern and bearing pattern and bearing Fabricated Turnstiles Figure 3 7 BEARING MOUNTING RING Gussets added near mounting holes and ring replace plate for additional rigidity Turnstile with br
31. position preferably safely secured to shipping pallets or in a container When lifting a bearing use eye bolts in the mounting holes or nonmetallic slings at three evenly distributed points around the bearing Avoid any sudden acceleration or impact If the bearing must be turned over use nylon web slings or equivalent Do not use chains or metallic mesh slings in contact with the bearing 2 2 Storage Kaydon slewing ring bearings are packed with general purpose grease at the factory unless specified by the customer and are sealed to exclude ordinary foreign matter Keep the bearing packaged as originally received and in a horizontal position until all preparations have been made for its installation If it is necessary to stack the bearings then a stable intermediate layer with adequate strength to support the weight must be used between bearings The overall stacked height must not exceed three feet We recommend that you do not stack more than two high if the bearing is four feet or larger in diameter Outdoor storage is not recommended If the bearing is not installed within one year of receiving it the grease should be purged and replaced with fresh grease External surfaces of slewing ring bearings including the gear are coated with a preservative oil to provide nominal protection during storage We suggest that you advise Kaydon if extended periods of storage are anticipated so that the bearings can be packaged appropriately
32. r In more rapidly moving or continuously rotating machinery such as trenchers borers and material distributors the bearing should be lubricated every day or every 8 hours of round the clock service Refer to Section 3 page 44 for futher discussion on lubricants to use Idle equipment should not be neglected Grease dries out and breathing due to temperature changes can cause condensation within the bearing Whether used or not the bearing should have grease introduced every 6 months The bearing should then be rotated a few revolutions to coat all surfaces with fresh grease 2 5 1 2 Gear There is a tendency to take much better care of the bearing than the gear However the meshing action and usual position of the gear tends to purge the lubricant thus the gear should be regreased frequently with a small amount of lubricant A well maintained gear will provide long smooth and quiet service It is recommended that grease be introduced at the point of mesh of pinion and gear every 8 hours of slow or intermittent operation and more often for rapidly or continuously rotating applications Refer to Section 3 page 44 for further discussion on lubricants to use 2 5 2 Bolts The cyclic nature of loading on the mounting bolts gives rise to the possibility of their working loose or to inelastic deformation of the threads and other stressed surfaces With the equipment in the same orientation as the initial testing during installa
33. roximate load on the heaviest loaded bolt This method is based upon past experience and yields results that have proved satisfactory for most applications It is analogous to the method Kaydon uses to determine the load on the heaviest loaded rolling element within a bearing A Kaydon makes no warranty expressed or implied regarding the adequacy of the bolts The only certain way to determine the actual load is by testing which is strongly recommended M Moment load ft Ibs F Flexibility factor Use 3 for bearings and support structures of average stiffness F Axial load Ibs If the load is in tension the sign is If the load is in compression the sign is Refer to Figures 2 2 and 2 3 12 M Fe p zi ON eRe RN a 3i i L n n a i9 xp Bolt Proof Load Rating x S Roo z D L Bolt circle diameter in n Total number of evenly distributed bolts Ry Total load on heaviest loaded bolt Ibs F Factor of safety of bolts Minimum recommended value 3 Bolt Proof Load SAE J429 Grade 8 and ASTM A490 Coarse Threaded Series Bolt Dia Proof Load in Ibs 1 2 17000 5 8 27100 3 4 40 100 7 8 55 400 1 72 700 1 1 8 91 600 1 1 4 116 300 12 168 600 1 800 514 3066 www kaydonbearings com ES Slewing Ring Bearings Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance If you determine that alteration to the mounting hole pattern
34. s Catalog 390 Kaydon Corporation Issue 11 Installation amp Maintenance 1 1 4 Access For Installation and Maintenance Like all mechanical components on a machine the bearing must be accessible so that it can be properly maintained The following must be considered Mounting bolts require periodic checking and possibly retightening Access to every mounting bolt must be readily available Failure to properly maintain the mounting bolts may result in failure and injury to anyone in the vicinity Lubrication of the gear and internal components is required and convenient access to the gear and bearing grease fittings must be provided It is recommended that remote lines to the bearing be added to allow rotation as grease is introduced to the raceways 1 There may be rare occasions when it is desirable to inspect the bearing raceways and internal components This should only be attempted by qualified personnel due to the potential for the bearing and structures to come apart This can damage components and cause injury or fatality to anyone in the vicinity This inspection may be accomplished on typical slewing ring bearings by removal of the loading plug excluding three row roller designs While removal of the loading plug voids the warranty it may be necessary To accommodate access to the retention pin for the loading plug the designer should include additional clearance or access holes above and below the retaining
35. tion the bolts should be checked by the end user within the first 200 to 300 operating hours Should any loss of pretension be detected the source must be determined and eliminated The bolts should be checked again after each additional 200 to 300 hours of operation until loss is no longer detected at which time the inspection frequency can be extended as specified by the designer 2 5 3 Seals Seals should be inspected during routine maintenance as recommended by the designer but the interval should not exceed 6 months Check for tears breaks or other signs of damage Depending on the lubrication frequency and protection it may be necessary to clean some areas to conduct this inspection Carefully remove any buildup of debris around the seal and lubricate the bearing There should be a small bead of grease around the seal edge indicating the bearing is receiving sufficient lubrication 2 5 4 Cleaning Cleaning should be done with material compatible with seals following all manufacturers instructions for use storage and disposal Take precautionary safety measures and use safe operating practices observing all relevant legal regulations when handling Do not expose the seal area or any other bearing opening to pressurized cleaning 2 5 5 Noise Roughness and Vibration Continued monitoring of equipment noise roughness and vibration during operation can assist in early detection of poor or unsafe components structural
36. tion time maintenance and economics The designer must also weigh potential for increased gear life versus additional cost incurred by requiring more stringent manufacturing tolerances or designing for an adjustable Figure 3 13 center distance Gear Assembly Backlash Table 3 14 Maximum Backlash in Gear Minimum Pitch Dia D Backlash J Diametral Pitch P4 in in 20 0 014 0 029 0 027 0 025 0 023 0 022 30 0 015 0 030 0 028 0 026 0 024 0 023 40 0 016 0 031 0 029 0 027 0 025 0 024 60 0 018 0055 0 031 0 029 0 027 0 026 80 0 020 0 035 0 033 0 031 0 029 0 028 100 0 022 0 037 0 035 0055 0 031 0 030 120 0 024 0 039 0 037 0 035 0 033 0 032 Please see Section 3 of website version of catalog for pending additions to this table PS www kaydonbearings com 1 800 514 3066 Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance 1 3 Mou nting Examples The mounting structures shown are intended to be illustrative only Important details in design such as mounting plate thickness location and number of stiffening members and bolt lengths must be determined by the equipment designer as detailed in previous sections Kaydon bearings can be designed to suit a number of mounting arrangements Following are illustrations of some basic arrangements These can be varied to suit the requirements of a specific application Such variations include types of holes location and number of lube ho
37. ubricant properties such as oil viscosity extreme pressure additives resistance to water washout low water absorption corrosion inhibition and oxidation resistance found in this list of greases provides an example of some of the properties readily available in the market Kaydon slewing ring bearings are pre lubricated with a lithium based mineral oil grease conforming to NLGI No 1 consistency with extreme pressure additives unless specifically noted Any grease inserted into the bearing must be compatible with this grease Please refer to Section 3 of this catalog for suggested lubrication procedure and frequencies along with other valuable information concerning installation care and maintenance Table of Appropriate Grease Lubricants for Kaydon Slewing Ring Bearings and their Open Gears Manufacturer Internal Bearing Grease Open Gear Grease BP Energrease LS EP 1 enn Castrol HD Lithium 1 Open Gear 800 Chevron Dura Lith EP 1 Chevron Open Gear Grease ExxonMobil Mobilux EP 1 EM D dde Kl ber Kl berplex BEM 41 141 Kl berplex AG 11 462 Lubricants USA FINA Marson EPL 1 Marson Open Gear Lubricant Shell Alvania EP 1 Malleus GL Texaco Multifak EP 1 Crater 2X asphaltic based PS www kaydonbearings com 1 800 514 3066
38. ure Calibrated tension indicating washers are acceptable Lockwashers are NOT recommended because of potentially significant variations in frictional resistance embedding and loss of bolt tension leading to permature failure of the bolt Additionally locking compound on the threads intended to prevent loosening is NOT recommended As mentioned in the maintenance section the bolts require frequent inspection for proper tension The most common method used to fulfill this requirement is measuring torque of the bolt The use of locking compound can lead to a false conclusion that the bolt has the desired tension Loss ofthe proper tension can lead to premature bolt failure dismounting of the bearing and structure damage to components and injury or fatality to anyone in the vicinity Kaydon Corporation Issue 11 Slewing Ring Bearings Catalog 390 Installation amp Maintenance i Crowning or changing of the tooth thickness along 1 1 5 2 Welding Attachment of bearings by welding is not favored and is limited to new applications in unusual situations If additional assistance is required we suggest that you contact the Kaydon Engineering Department for these applications 1 2 Pinion and Gear Mesh 1 2 1 Pinion Design Considerations If a bearing with an integral gear has been selected the machine designer should work with a pinion manufacturer to select the appropriate mating pinion It is important to be aware and consi
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