10 Thrust ball bearings

Transcription

1 Rolling bearings

2

3 10 Thrust ball bearings Designs and variants Single direction thrust ball bearings Double direction thrust ball bearings Cages Bearings with sphered housing washers Bearing data (Dimension standards, tolerances, misalignment, friction, starting torque, power loss, defect frequencies) Loads (Minimum load, equivalent loads) Temperature limits Permissible speed Product tables 10.1 Single direction thrust ball bearings Single direction thrust ball bearings with a sphered housing washer Double direction thrust ball bearings Double direction thrust ball bearings with sphered housing washers Other thrust ball bearings Bearings with Solid Oil SKF DryLube bearings NoWear coated bearings Polymer ball bearings Mounting Designation system

4 10 Thrust ball bearings Designs and variants SKF thrust ball bearings are manufactured as single direction or double direction thrust ball bearings. They are designed to accommodate axial loads only and must not be subjected to any radial load. SKF thrust ball bearings are separable, i.e. the shaft washer, housing washer(s), ball and cage assembly(s) can be mounted separately. Shaft washers have a ground bore to enable an interference fit. The bore of the housing washer is turned and always larger than the shaft washer bore. Single direction thrust ball bearings SKF single direction thrust ball bearings consist of a shaft washer, a housing washend a ball and cage assembly ( fig. 1). As their name implies, single direction thrust ball bearings can accommodate axial loads and locate a shaft axially, in one direction only. Fig. 1 Shaft washer Housing washer Fig. 2 Housing washers Double direction thrust ball bearings SKF double direction thrust ball bearings consist of one shaft washer, two housing washers and two ball and cage assemblies ( fig. 2). The housing washers and ball and cage assemblies of double direction bearings are identical to those used in single direction bearings. Double direction thrust ball bearings can accommodate axial loads and locate a shaft axially, in both directions. Shaft washer More information Bearing life and load ratings Design considerations Recommended fits Abutment and fillet dimensions Lubrication Mounting, dismounting and bearing care Cages Depending on their series and size, SKF thrust ball bearings are fitted with one of the cages shown in table 1. The lubricants generally used for rolling bearings do not have a detrimental effect on cage properties. Fodditional information about the suitability of cages, refer to Cages ( page 37) and Cage materials ( page 152). 1010

5 Designs and variants Bearings with sphered housing washers To accommodate initial misalignment between the shaft and housing, SKF supplies both single and double direction thrust ball bearings with sphered seat surfaces on the housing washers ( fig. 3). They can be used together with a sphered seat washedjacent to the housing washer ( figs. 4 and 5) odjacent to a machine component manufactured with a sphered surface. Appropriate sphered seat washers must be ordered separately ( product tables). Depending on the bearing series, they have the basic designation U 2, U 3 or U 4 followed by a two-digit number, which identifies the size (e.g. sphered seat washer U 320 for bearing 53320). Shaft washer Housing washer Fig. 3 Fig. 4 Table 1 Cages for thrust ball bearings Housing washer Seat washer 10 Fig. 5 Cage description Stamped steel, ball centred Machined brass, ball centred Machined steel, ball centred Suffix M F Housing washers Seat washers 1011

6 10 Thrust ball bearings Bearing data Thrust ball bearings Dimension standards with flat housing washers ISO 104 Bearings in the BA series are not standardized. with sphered housing washer(s) ISO Tolerances Fodditional information ( page 132) Normal P5 or P6 on request (single direction bearings only) Normal Values: ISO 199 ( table 10, page 144) Bearings in the BA series are not standardized. Misalignment Accommodate initial misalignment between the support surfaces in the housing and on the shaft. Friction, starting torque, power loss Defect frequencies Frictional moment, starting torque, and power loss can be calculated as specified under Friction ( page 97), or using the tools available online at skf.com/bearingcalculator. Defect frequencies can be calculated using the tools available online at skf.com/bearingcalculator. 1012

7 Loads Loads Minimum load Fodditional information ( page 86) Equivalent dynamic bearing load Fodditional information ( page 85) Equivalent static bearing load q n w 2 F am = A < z The weight of the components supported by the bearing, particularly when the shaft is vertical, together with external forces, generally exceed the requisite minimum load. If this is not the case, the bearing must be subjected to an additional axial load, e.g. by springs. P = F a P 0 = F a Symbols A = minimum load factor ( product tables) F a = axial load [kn] F am = minimum axial load [kn] n P = rotational speed [r/min] = equivalent dynamic bearing load [kn] P 0 = equivalent static bearing load [kn] Fodditional information ( page 88)

8 10 Thrust ball bearings Temperature limits The permissible operating temperature for thrust ball bearings can be limited by: the dimensional stability of the bearing washers and balls the cage the seat washer(s) the lubricant Mounting When installing a single direction thrust ball bearing it is important to differentiate between the shaft washend the housing washer. The bore of the shaft washer is ground and always smaller than the bore of the housing washer. The shaft washer should always be placed against a shaft step or fixed shaft component. When temperatures outside the permissible range are expected, contact the SKF application engineering service. Bearing washers and balls The washers and balls of SKF thrust ball bearings undergo a special heat treatment. De pending on their size they are heat stabilized up to: 125 C (260 F) when d 300 mm 150 C (300 F) when d > 300 mm Cages Steel and brass cages can be used at the same operating temperatures as the bearing washers and balls. Seat washers Seat washers are made of steel and can be used at the same operating temperatures as the bearing washers and balls. Lubricants Temperature limits for SKF greases are provided under Lubrication ( page 239). When using lubricants not supplied by SKF, the temperature limits should be evaluated according to the SKF traffic light concept ( page 244). Permissible speed The permissible speed can be estimated using the speed ratings listed in the product tables and applying the information provided under Speeds ( page 117). 1014

9 Designation system Designation system Group 1 Group 2 Group 3 / Group Prefixes Basic designation Listed in diagram 2 ( page 43) BA. Thrust ball bearing, bore diameter d < 10 mm The one-digit numbefter BA identifies the bore diameter. Suffixes Group 1: Internal design Group 2: External design (seals, snap ring groove etc.) Group 3: Cage design F M Machined steel cage, ball centred Machined brass cage, ball centred Group 4.1: Materials, heat treatment Group 4.2: Accuracy, clearance, preload, quiet running P5 P6 Dimensional and running accuracy to P5 tolerance class Dimensional and running accuracy to P6 tolerance class Group 4.3: Bearing sets, matched bearings Group 4.4: Stabilization Group 4.5: Lubrication 10 Group 4.6: Other variants 1015

10 10.1 Single direction thrust ball bearings d 3 30 mm d 1 d D 1 D H Principal dimensions Basic load ratings Fatigue dynamic static load limit d D H C C 0 P u A Minimum load factor Speed ratings Mass Designation Reference Limiting speed speed mm kn kn r/min kg 3 8 3,5 0,806 0,72 0,027 0, ,0009 BA ,761 0,72 0,027 0, ,0015 BA ,852 0,965 0,036 0, ,0021 BA ,78 1,92 0,071 0, ,0035 BA ,51 2,9 0,108 0, ,0065 BA ,19 3,8 0,143 0, ,0091 BA ,12 3,8 0,143 0, ,01 BA ,95 15,3 0,56 0, , ,7 18,6 0,695 0, , ,4 16,6 0,62 0, , ,3 20,8 0,765 0, , ,6 18,3 0,67 0, , ,9 25 0,915 0, , ,4 21,2 0,78 0, , , , , ,1 29 1,08 0, , ,2 37,5 1,4 0, , ,2 39 1,43 0, , ,5 50 1,86 0, , ,5 60 2,24 0, , ,3 67 2,45 0, , ,6 0, , ,1 51 1,86 0, , ,8 65,5 2,4 0, , , ,5 0, ,

11 d a D a Dimensions Abutment and fillet dimensions d d 1 D 1,2 d a D a ~ ~ min. min. max. max. mm mm 3 7,8 3,2 0,15 5,8 5 0,15 4 9,8 4,2 0,15 7,5 6,5 0, ,8 5,2 0, , ,8 6,2 0,2 11 9,5 0,2 7 16,8 7,2 0,2 12,5 11 0,2 8 18,8 8,2 0,3 14,5 12,5 0,3 9 19,8 9,2 0,3 15,5 13,5 0, , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

12 10.1 Single direction thrust ball bearings d mm d 1 d D 1 D H Principal dimensions Basic load ratings Fatigue dynamic static load limit d D H C C 0 P u A Minimum load factor Speed ratings Mass Designation Reference Limiting speed speed mm kn kn r/min kg ,9 51 1,86 0, , ,1 73,5 2,7 0, , ,4 96,5 3,55 0, , , ,1 0, , ,5 63 2,32 0, , ,2 96,5 3,6 0, , , ,5 0, , , ,8 0, , ,5 69,5 2,55 0, , ,5 3,2 0, , , ,6 0, , , , ,8 0, , , ,3 0, , , ,3 0, , ,5 0, ,2 81,5 3 0, , , ,9 0, , ,3 0, , ,6 0, , , ,55 0, , , ,1 0, , ,3 0, , , , M , , , , ,5 0, , ,8 0, , , M , ,4 0, , , ,85 0, , ,8 0, ,3 1, M 1018

13 d a D a Dimensions Abutment and fillet dimensions d d 1 D 1,2 d a D a ~ ~ min. min. max. max. mm mm , , , , , , , , , , , , , , , , , , , , , , , ,

14 10.1 Single direction thrust ball bearings d mm d 1 d D 1 D H Principal dimensions Basic load ratings Fatigue dynamic static load limit d D H C C 0 P u A Minimum load factor Speed ratings Mass Designation Reference Limiting speed speed mm kn kn r/min kg , ,9 0, , , ,2 0, , , , ,8 1, , M , ,1 0, , , ,65 0, , ,7 0, , , , M , ,4 0, , , ,8 0, , , , , , M , ,5 0, , ,4 0, , ,6 1, , ,5 3, M , ,15 0, , ,8 0, , ,3 1, , ,5 5, M , ,5 0, , ,6 0, , , ,5 3, , M ,5 7, M , ,65 0, , , , , M , M ,4 0, , , , M M 1020

15 d a D a Dimensions Abutment and fillet dimensions d d 1 D 1,2 d a D a ~ ~ min. min. max. max. mm mm , , , , , , , , , , , , , , , , , , , , , , ,

16 10.1 Single direction thrust ball bearings d mm d 1 d D 1 D H Principal dimensions Basic load ratings Fatigue dynamic static load limit d D H C C 0 P u A Minimum load factor Speed ratings Mass Designation Reference Limiting speed speed mm kn kn r/min kg , , , , ,5 9, , M , M , , M , , M , M , M ,9 1, , M ,4 3, , M , M ,3 1, , M , , M M , , M ,5 6, , M , , M , , M , M , M ,6 2, , M ,5 9, M , , M , , M , M ,6 5, , M , M , , M , M , M , , M 1022

17 d a D a Dimensions Abutment and fillet dimensions d d 1 D 1,2 d a D a ~ ~ min. min. max. max. mm mm , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

18 10.1 Single direction thrust ball bearings d mm d 1 d D 1 D H Principal dimensions Basic load ratings Fatigue dynamic static load limit d D H C C 0 P u A Minimum load factor Speed ratings Mass Designation Reference Limiting speed speed mm kn kn r/min kg , , M M , M , F , , M , , F F , F F F , F , , F F , F , F /500 F ,5 511/530 F /560 F , /600 F , /630 F , /670 F 1024

19 d a D a Dimensions Abutment and fillet dimensions d d 1 D 1,2 d a D a ~ ~ min. min. max. max. mm mm , , , , , , , , , , ,

20 10.2 Single direction thrust ball bearings with a sphered housing washer d mm R d 1 d D 1 D s H C D 2 D 3 H 1 Principal dimensions Basic load ratings dynamic static Fatigue load limit d D H 1 C C 0 P u A Minimum load factor Speed ratings Mass Designations Reference Limiting Bearing speed speed Bearing incl. washer Seat washer mm kn kn r/min kg ,3 20,8 0,765 0, , U ,9 25 0,915 0, , U , , , U ,2 37,5 1,4 0, , U ,5 50 1,86 0, , U ,1 51 1,86 0, , U ,8 65,5 2,4 0, , U ,1 73,5 2,7 0, , U ,4 96,5 3,55 0, , U ,2 96,5 3,6 0, , U , ,5 0, , U , ,8 0, , U ,5 3,2 0, , U , ,6 0, , U , ,3 0, , U , ,3 0, , U ,5 0, , U , ,9 0, , U ,3 0, , U ,6 0, , U , ,1 0, , U ,3 0, , U , , M U , ,5 0, , U ,8 0, , U , ,85 0, , U ,8 0, , U ,3 1, , M U

21 R d a D a Dimensions Abutment and fillet dimensions d d 1 D 1 D 2 D 3 H C R s,2 d a D a ~ ~ min. min. max. max. mm mm ,4 3, ,5 0, , , , , , , , , , , ,7 5, , , ,8 5, , , , , ,6 7, , , ,5 8, , , ,3 7, , ,5 7, , , , , , , , ,3 11, , ,5 15, , , , ,3 11, , , , ,4 12, ,5 1, , , ,6 19,

22 10.2 Single direction thrust ball bearings with a sphered housing washer d mm R d 1 d D 1 D s H C D 2 D 3 H 1 Principal dimensions Basic load ratings dynamic static Fatigue load limit d D H 1 C C 0 P u A Minimum load factor Speed ratings Mass Designations Reference Limiting Bearing speed speed Bearing incl. washer Seat washer mm kn kn r/min kg , ,2 0, U , , U ,8 1, , M U , ,65 0, , U ,7 0, , U , , , U , , U ,4 0, , U ,6 1, , U ,5 3, M U ,8 0, , U ,3 1, , U ,5 5, M U ,6 0, , U ,5 3, , M U , , U , , M U , , U , , U

23 R d a D a Dimensions Abutment and fillet dimensions d d 1 D 1 D 2 D 3 H C R s,2 d a D a ~ ~ min. min. max. max. mm mm ,3 9, , , , , , , ,1 17, , ,5 13, , , , ,2 25, , , , , , , , , , , , , , , , ,

24 10.3 Double direction thrust ball bearings d mm d B r 4 r 3 H D 1 D Principal dimensions Basic load ratings dynamic static Fatigue load limit d D H C C 0 P u A Minmum load factor Speed ratings Mass Designation Reference speed Limiting speed mm kn kn r/min kg , , , ,2 37,5 1,4 0, , ,5 50 1,86 0, , ,5 60 2,24 0, , , ,5 0, ,7 46,5 1,86 0, , ,8 65,5 2,4 0, , , ,1 0, , ,1 73,5 2,7 0, , ,2 96,5 3,6 0, , ,4 96,5 3,55 0, , , ,5 0, , , ,8 0, , ,5 3,2 0, , , ,6 0, , , , , ,3 0, , , ,3 0, , , ,9 0, , ,3 0, , ,6 0, , , ,1 0, , ,3 0, , , , M , ,5 0, , , ,85 0, , ,8 0, , ,8 0, , ,3 1, , M , ,2 0, , , ,

25 D a d a r b Dimensions Abutment and fillet dimensions d D 1 B,2 r 3,4 d a D a r b ~ min. min. max. max. max. mm mm ,6 0, ,6 0, ,6 0, ,6 0, ,6 0, ,6 0, , , , , ,6 0, ,6 0, , , ,1 0, , , , , , , , , , ,1 0, , , , , , ,1 0, , , , ,1 0, , , , ,1 0, , ,5 0, ,5 0, , , ,1 0, , ,5 0, ,5 0, , , ,1 0, , , , , ,

26 10.3 Double direction thrust ball bearings d mm d B r 4 r 3 H D 1 D Principal dimensions Basic load ratings dynamic static Fatigue load limit d D H C C 0 P u A Minmum load factor Speed ratings Mass Designation Reference speed Limiting speed mm kn kn r/min kg , ,65 0, , ,7 0, , , ,8 0, , , , ,8 0, , ,3 1, , ,6 0, , , , , , , , , M ,4 3, M , M ,5 6, M 1032

27 D a d a r b Dimensions Abutment and fillet dimensions d D 1 B,2 r 3,4 d a D a r b ~ min. min. max. max. max. mm mm , , , , , ,1 1, ,5 1, , ,5 1, , ,5 1, , ,5 1, , ,5 1, , , ,

28 10.4 Double direction thrust ball bearings with sphered housing washers d mm d s B r 4 r 3 H H 1 R D 1 D C D 2 D 3 Principal dimensions Basic load ratings Fatigue Minimum Speed ratings Mass Designations dynamic static load limit load factor Reference speed Limiting speed Bearing incl. Bearing Seat washer d D H 1 C C 0 P u A washer mm kn kn r/min kg ,8 65,5 2,4 0, , U ,1 73,5 2,7 0, , U ,2 96,5 3,6 0, , U ,4 96,5 3,55 0, , U , ,5 0, , U ,5 3,2 0, , U , ,6 0, , U , U , ,3 0, , U ,4 0, , U , ,9 0, , U ,3 0, , U ,7 0, , U , , M U , , U ,5 5, M U

29 skf.com