《工业齿轮箱的滚子轴承 - 第一部分.pdf》由会员分享，可在线阅读，更多相关《工业齿轮箱的滚子轴承 - 第一部分.pdf（117页珍藏版）》请在三一文库上搜索。
1、Rolling bearings in industrial gearboxes Copyright SKF 1997 The contents of this publication are the copyright of the publisher and may not be reproduced (even extracts) unless permission is granted. Every care has been taken to ensure the accuracy of the information contained in this publi- cation
2、but no liability can be accepted for any loss or damage whether direct, indirect or consequential arising out of the use of the information contained herein. Publication 4560 E Printed in Denmark on environmentally friendly, chlorine-free paper (Multiart Silk) by Scanprint as 1 Industrial gearboxes
3、overview 2 Bearing types for industrial gearboxes 3 Design of bearing arrangements 4 Dimensioning the bearing arrangement 5 Lubrication and maintenance 6 Recommended fits 7 Mounting and dismounting bearings 8 Application examples 1 2 3 4 5 6 7 8 Rolling bearings in industrial gearboxes Rolling beari
4、ngs in industrial gearboxes Handbook for the gearbox designer Foreword This Handbook is intended to provide the gearbox designer with the knowledge required to select bearings for gearboxes and to correctly design gearbox bearing arrangements. Recom- mendations are given based on experience gained b
5、y SKF during decades of cooperation with gearbox manufacturers the world over. General information regarding the selection, calculation, mounting and maintenance of ball and roller bearings is given in the SKF General Catalogue. The questions arising from the use of rolling bearings in industrial ge
6、arboxes are dealt with here. Data from the General Catalogue are only repeated here when it has been thought necessary for the sake of clarity. The application examples described comprise proven gearbox designs from major manufacturers which are worthy of note. Grateful thanks are extended to the co
7、mpanies concerned for the provision of the detailed information about their prod- ucts and the permission to publish. 3 Rolling bearings in industrial gearboxes 4 1Industrial gearboxes overview. 9 Types of gearbox 9 Geared transmissions10 Demands made on gearboxes 14 Selecting the gears 14 Designing
8、 the casing .15 2Bearing types for industrial gearboxes17 Deep groove ball bearings 18 Angular contact ball bearings.20 Cylindrical roller bearings.22 CARB roller bearings .24 Spherical roller bearings .26 Taper roller bearings28 Spherical roller thrust bearings30 3Design of bearing arrangements.33
9、Shafts and gear wheels in spur gearboxes .33 Shafts in bevel gearboxes.44 Shafts in worm gearboxes.50 Shafts and gear wheels for planetary gearboxes56 Made by SKFstands for excellence. It symbolises our consistent endeavour to achieve total quality in everything we do. For those who use our products
10、, “Made by SKF” implies three main benefits. Reliability thanks to modern, efficient products, based on our worldwide application know-how, optimised materials, forward-looking designs and the most advanced production techniques. Cost effectiveness resulting from the favourable ratio between our pro
11、duct quality plus service facilities, and the purchase price of the product. Market lead which you can achieve by taking advantage of our products and services. Increased operating time and reduced down-time, as well as improved output and product quality are the key to a successful partnership. Con
12、tents 5 4Calculation of bearing arrangement.65 Bearing loads .65 Determination of external forces66 Calculation of bearing loads.74 Dimensioning the bearing arrangement 76 5Lubrication and maintenance91 Grease lubrication92 Oil lubrication.95 Maintenance .98 6Recommended fits103 7Mounting and dismou
13、nting bearings109 Adjustment of angular contact bearings109 8Application examples.115 Rolling bearings in industrial gearboxes 6 SKF is an international industrial Group operating in some 130 countries and is world leader in bearings. The company was founded in 1907 following the invention of the se
14、lf-align- ing ball bearing by Sven Wingquist and, after only a few years, SKF began to expand all over the world. Today, SKF has some 43 000 em- ployees and more than 80 manufactur- ing facilities spread throughout the world. An international sales network includes a large number of sales com- panie
15、s and some 20 000 distributors and retailers. Worldwide availability of SKF products is supported by a com- prehensive technical advisory service. The key to success has been a con- sistent emphasis on maintaining the highest quality of its products and services. Continuous investment in research an
16、d development has also played a vital role, resulting in many examples of epoch-making innovations. The business of the Group consists of bearings, seals, special steel and a comprehensive range of other high- tech industrial components. The ex- perience gained in these various fields provides SKF w
17、ith the essential know- ledge and expertise required in order to provide the customers with the most advanced engineering products and efficient service. The SKF Group a worldwide corporation SKF manufactures ball bearings, roller bearings and plain bearings. The smal- lest are just a few millimetre
18、s (a frac- tion of an inch) in diameter, the largest several metres. In order to protect the bearings effectively against the ingress of contamination and the escape of lubricant, SKF also manufactures oil and bearing seals. SKFs subsidiaries CR and RFT S.p.A. are among the worlds largest pro- ducer
19、s of seals. 7 The SKF house colours are blue and red, but the thinking is green. The latest example is the new factory in Malaysia, where the bearing component cleaning process con- forms to the strictest ecological standards. Instead of trichloroethylene, a water-based cleaning fluid is used in a c
20、losed system. The cleaning fluid is recycled in the factorys own treatment plant. SKF has developed the Channel concept in factories all over the world. This drastically reduces the lead time from raw material to end product as well as work in progress and finished goods in stock. The concept enable
21、s faster and smoother information flow, eliminates bottlenecks and bypasses unnecessary steps in production. The Channel team members have the know- ledge and commitment needed to share the responsibility for fulfilling objectives in areas such as quality, delivery time, production flow etc. The SKF
22、 Engineering deformations Operating conditionsBearing series normally used Input shaftIntermediateOutputIntermediateShifting shaftshaftgearsgears Light loads626361960618/C3 63NJ 2 EC16062619/C3 60 Moderate loadsNJ 2 EC NJ 22 ECNCF 29 VNJ 2 EC160/C3 320 X322239 CC320 X60/C3 222 E(CC)222 E(CC) Heavy l
23、oads322NJ 23 EC230 CC NJ 3 EC62/C3 232 CCNJG 23 VH303 223 E(CC)223 E(CC)232 CC 322/DF223 E(CC) High speedsNU 2 ECMA/C3 QJ 2 N2MA/C4 In addition to the bearing series listed above, a CARB can be used as the non-locating bearing for locating/non-locating bearing arrangements Table4 Table5 Shafts in be
24、vel gearboxes Bevel gears are generally speed reduction gears. The high-speed drive shaft is termed the pinion shaft and the slow-speed driven shaft carries the larger bevel gear wheel. The pinion shaft is driven by the motor via a coupling, a spur gear or a belt drive. The power take-off is either
25、via a coupling or with bevel/spur gears via a pinion. Pinion shafts The pinion is generally supported in an overhung arrangement. In a few cases the pinion is supported between the bearings but it is difficult to design in a bearing with sufficiently high load car- rying capacity at the head. The ov
26、er- hung arrangement offers more space. Two taper roller bearings in a back- to-back arrangement as shown in figoffer a cost-favourable and axi- ally as well as radially stiff arrangement for small to medium diameter shafts (d 150 mm). When using cylindrical roller bearings aim for small roller diam
27、eters; use a full complement bearing. Wear caused by contaminantsAvoid contaminating the gearbox during production, assembly and in operation. Table6 Table7 To obtain good meshing it is neces- sary among other things to have a bearing arrangement with high radial and axial stiffness. The locating be
28、ar- ing should therefore have a large contact angle and as small an axial clearance as possible. Bearings for the output shaft These bearings are predominantly radially loaded so that high radial load carrying capacity is also required of the locating bearing. Because of the slow speeds the risks in
29、 respect of thermal behaviour and over-dimension- ing compared with the pinion shaft are negligible. The requirements for axial and radial stiffness, for minimum axial clearance and for bearing accuracy correspond to those for the pinion shaft bearings. Bearing selection When selecting the bearings
30、it is use- ful to refer to the cheklist given below. Adjusted basic rating life Permissible speed Axial and radial stiffness Sufficient bearing clearance in the mounted but cold state to avoid inad- missible preload under conditions of maximum temperature differentials Minimum load A preliminary sel
31、ection can be made using the overview of the bearing series commonly used; see Table.8 Bearing selection 49 3 3Design of bearing arrangements Shafts in bevel gearboxes Bearing Bearing series normally used arrangement Bevel pinion shaftBevel gear wheel/Bevel/spur gear wheel Input sidePinion sideGear
32、wheel sideOpposite side or spur pinion side Cross location72 BE72 BE72 BE72 BE 73 BE73 BE73 BE73 BE 313323 B322322 323 B323 B 332332 303303 323323 Locating bearing(s)(2) 72 BECB33 (2) 73 BECB(2) 72 BECB 313/DF(2) 73 BECB 322 + 293 E320 X/DF 322/DF 303 + 294 Non-locatingNU 22 EC(/C3)NU 2 EC bearingNU
33、 23 EC(/C3)NU 22 EC 232 CC(/C3)NU 3 EC 223 CC(/C3)NU 23 EC 223 EC In addition to the bearing series listed above, a CARB can be used as the non-locating bearing for locating/non-locating bearing arrangements Table8 Shafts in worm gearboxes Generally worm gearboxes are used to reduce speed. There are
34、 two main types: one for mounting on the machine base and a cartridge type for mount- ing on the input (drive) shaft of the machine. The drive from the prime mover is either via a coupling or a belt drive. The power take-off is via a coupling or a quill (hollow) shaft connection. Worm shafts The hea
35、viest axial loads act on the worm shaft at the same time as speeds are high. Where there is a belt drive, the radial loads will also be heavy. ment ( fig) offer a cost-favour- able, low friction bearing arrangement with low noise for moderate perform- ance and where diameters are small (bearing bore
36、 diameter d 50 mm). The angular contact ball bearings are suitable for high speeds and because of the large contact angle they are also appropriate for predominantly axial loads. The two bearings are adjusted against each other via the cover so that they will have a slight preload when running at th
37、e operating temperature. When determining the degree of adjust- ment it is necessary to consider the temperature differential between shaft and casing, but also casing deforma- tion. 24 The temperature differences and the associated thermal expansion in the radial and axial directions are also large
38、 in worm gearboxes. Only small masses and surfaces of the worm shafts are available to remove heat. Therefore, there are large temperature gradients from the shaft to the casing and these must be considered when adjusting the bearings. The distance between bearings is dictated by the casing and toge
39、ther with the small torques this often leads to the use of slim shafts. If there is a belt drive, then shaft bending should be calculated so that inadmissible bearing misalignment can be avoided. Two single row angular contact ball bearings in a cross-located arrange- The same type of arrangement bu
40、t using two steep-angled taper roller bearings ( fig) can carry heavier loads than that with the angular con- tact ball bearings for the same shaft diameter. Therefore, taper roller bear- ings are preferred for higher perform- ance gearboxes and for medium to large diameters. When determining the de
41、gree of adjustment, it must be remembered that taper roller bearings are axially stiffer than angular contact ball bearings and are therefore more sensitive to excessive preload. It is thus advisable to aim at zero clear- ance when the bearings are running at the operating temperature. When start- i
42、ng up (worm already warm, casing still cold) a slight preload will be pre- 25 Bearing arrange- ment for a worm shaft with two taper roller bear- ings arranged face-to-face Bearing arrange- ment for a worm shaft with two angular contact ball bearings in a cross-located arrangement 50 3Design of beari
43、ng arrangements Shafts in worm gearboxes sent which experience shows can be tolerated when lubrication is good. The locating/non-locating bearing arrangement ( fig) is more costly from a design point of view and be- cause a third bearing is involved but it has the following advantages: higher load c
44、arrying capacity (e.g. for belt tension forces); if paired angular contact ball bear- ings are used, no individual adjust- ment is required; axial displacement at the non-locat- ing bearing position is guaranteed. A further performance increase can be obtained by replacing the pair of angu- lar cont
45、act ball bearings by two match- 26 ed single row taper roller bearings (DF execution) as shown in fig. The intermediate ring which is sup- plied with the bearing pair ensures that there is a minimum axial clearance in the mounted condition, which is suffi- cient for temperature differentials be- twe
46、en shaft and casing of up to 20 C. In order not to deform the thin-walled intermediate ring when the cover scre- ws are tightened, the spigot (centring shoulder) in the cover should have a length such that a preload correspon- ding to approximately 0,01 mm can be obtained. 27 Bearing arrange- ment f
47、or a worm shaft with two matched angular contact ball bear- ings (locating position) and one cylindrical roller bearing (non- locating position) Bearing arrange- ment for a worm shaft with two matched taper roller bearings (locating position) and one cylindrical roller bearing (non-locating position
48、) 51 3 3Design of bearing arrangements Shafts in worm gearboxes The bearing arrangement shown in figis particularly suitable when the axial load in one direction predomin- ates, as for example in lifting gear. The spherical roller thrust bearing takes the dominant axial load as well as the axial for
49、ce produced in the taper roller bear- ing, which in this case is only subjected to radial load. If the axial load changes direction, then the taper roller bearing takes the radial as well as the axial load, while the spherical roller bearing is spring loaded to give the minimum axial load required for the correct mo- tion of the rollers. Both bearings are adjusted via the cover. When determin- ing the axial clearance it is necessary to consider the temperature differential between shaft and casing. 28 The advantages of this bearing arrangement are the very