WO2016086933A1

WO2016086933A1 - Rolling bearing, for example a contact ball bearing for bearing quickly spinning spindles in machine tools

Info

Publication number: WO2016086933A1
Application number: PCT/DE2015/200518
Authority: WO
Inventors: Michael Pausch; Gabriele Laugisch; Tobias Hock
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2014-12-03
Filing date: 2015-11-25
Publication date: 2016-06-09
Also published as: DE102014224710A1

Abstract

The invention relates to a rolling bearing (1), for example a contact ball bearing for bearing quickly spinning spindles in machine tools, comprising an outer ring (2) with an outer lateral surface (3) and an outer ring track (5) which is formed in an inner lateral surface (4) of the outer ring (2), an inner ring (6) with an inner ring track (8) which is formed in an outer lateral surface (7) of the inner ring (6), rolling bodies (9) which are arranged so as to roll in the outer ring track (5) and in the inner ring track (8), and at least one lubricant bore (1) which is arranged in the outer ring (2) and which runs from the lateral surface (3) of the outer ring to the proximity of the outer ring track (5) on the inner lateral surface (4). The aim of the invention is to increase the service life of the lubricant supplied via the lubricant bore. According to the invention, this is achieved in that the at least one lubricant bore (11) is formed in an inclined manner in the circumferential direction of the bearing ring (2) at an angle (q) of 90° > α > 0° relative to a straight radial line (20), which is perpendicular to the longitudinal axis of the rolling bearing (1), in the outer ring (2) and/or in the inner ring (6).

Description

Name of the invention

Rolling bearings, such as angular contact ball bearings for the storage of schnei! rotating spindles in machine tools Field of the invention

The invention relates to a rolling bearing, for example, a Veryägkugeliager for the storage of high-speed spindles in machine tools, with an outer ring with an outer circumferential surface and with a formed in an inner shell surface of the outer ring outer ring raceway, with an inner ring with a in an outer Lateral surface of the inner ring formed inner ring raceway. with Wälzkörpem arranged in the outer ring raceway and in the inner ring raceway, and with at least one arranged in the outer ring, from its outer circumferential surface to close to the Außenringiauf- path on the inner circumferential surface guided lubricant bore.

Rolling bearings require a sufficient supply of lubricant to operate. Especially at high speeds, the lubricant gets! The advantage of a grease lubrication lies essentially in the possibility to provide a lubricant reservoir, which ensures a sufficient supply of Wälzkonla- tes with lubricant even in case of failure of a lubricant supply unit. A disadvantage of grease lubrication is the relatively fast consumption of the grease at very high speeds. In such operating conditions, the lubricating grease is loaded in such a way that it is not possible to provide a lifetime lubrication with the lubricant supply once introduced in the roller bearing.

From DE 102 35 239 B4, a lubricated by lubricating grease Schrägku- geiiager is known, with the relubrication with grease during its operation is possible by from time to time arranged in the outer ring, pure radial lubricant bores grease close to the rolling contact is brought. Although the execution of a purely radial bore represents the minimum expenditure in terms of production technology, it leads to a high mechanical stress on the lubricating grease during conveyance through the lubricant bore. For the distribution of the lubricant on the entire circumference of the bearing is in the morning! a circumferential groove either in the outer circumferential surface of the outer ring of the rolling bearing or in a circumferential groove in the inner circumferential surface of the receiving bore of the rolling bearing provided in a housing

In the case of purely radially extending lubricant bores, which should not be in the area of the pressure cell, the annular groove must be positioned laterally offset from the center. Furthermore, the groove for the delivery of the grease should be designed with the largest possible cross-section in order not to damage the grease by shearing. If necessary, it is necessary to seal the lubricant groove to the environment by light elements arranged on both sides, for example by means of O-rings, in order to avoid having to accept any pressure losses or leakage losses during relubrication. These sealing elements are located next to the lubricant groove in grooves arranged for this purpose. This leads to difficulties if at the same time the standardized edge rounding should be adhered to and is not possible especially for axially narrow bearings or feasible only by a strong narrowing of tolerances and Nutdimensionen. Above all, the narrowing of the tolerances leads to high production costs. Furthermore, the transition from the circumferential groove to purely radially extending lubricant bores is relatively sharp, as a result of which the grease is additionally sheared and damaged during the conveyance of the lubricant groove through the lubricant bores.

From US 3,195,965 a rolling bearing is known, in the outer ring of a side surface outgoing, obliquely axially extending lubricant bores are arranged. These lead to the area of the rolling element cage and serve for this purpose. Introduce lubricant and / or air in the manner in the rolling bearing, that the cage in operation does not touch the ribs on the outer ring and inner ring, but is floating between them. The lubricant also gets in the area of the rolling elements and lubricates them. These lubricant bores are inclined only in the axial direction and otherwise run purely radially

The same applies to the rolling bearing known from US Pat. No. 3,722,967, the rolling element of which is supplied with lubricant via nozzles, which is supplied to an oil collecting container via obliquely axially inclined radial lubricant bores arranged in the outer ring and from there back into the lubricant circuit.

Object of the invention

Against this background, the invention has the object vorzzuschlagen for a rolling bearing of the type mentioned an arrangement of the lubricant supply, which avoids the disadvantages of the known bearings by the shear stress of the lubricant is reduced by a changed course of the lubricant holes in the rolling bearing Without significantly increased manufacturing costs arise in such a bearing.

Description of the invention

This object is achieved by a roller bearing, for example an angular contact ball bearing for the mounting of high-speed spindles in machine tools, with an outer ring with an outer circumferential surface and with an outer ring raceway formed in an inner circumferential surface of the outer ring, with an inner ring a innenringiaufbahn formed in an outer circumferential surface of the Snnenrings, rolling in the Außenringlaufbahn and in the inner ring runway arranged rolling bodies. and at least one Schrniermittelbohrung arranged in the outer ring, from its outer lateral surface to close to the nnglaufbahn on the inner lateral surface guided in that in the outer ring and / or in the inner ring, the at least one Schrniermitteibohrung in the circumferential direction of the bearing ring at an angle α of 90 ° >α> 0 ° with respect to a radial straight line which is perpendicular to the longitudinal axis of the rolling bearing, is formed inclined Due to the inclination of the at least one lubricant bore in the circumferential direction, the lubricant can flow unhindered through the lubricant bore and get into the interior of the rolling bearing in circumferential direction, whereby the shear stress of the lubricant is reduced and its service life is increased. Although the manufacturing costs are slightly higher than those of a radial lubricant bore, they are offset by the longer life of the grease in the bearing, which requires less frequent replenishment of lubricant into the bearing.

The angle of attack α of the at least one lubricant bore is preferably 5 ° or more. The angle α in an application, for example, 45 ° and more.

In addition, the at least one lubricant bore can be arranged inclined in the axial direction of the rolling bearing at an angle β, so that the inlet of the at least one lubricant bore comes to lie in the middle of the outer circumferential surface of the outer ring, although the outlet of this at least one lubricant bore in The inner lateral surface of the outer ring outside the pressure ellipse of the rolling bearing opens This angle ß is also at least 5 °, but it can be up to 45 ° and more, depending on the width of the bearing

Preferably, a plurality of lubricant bores are provided, which run in the circumferential direction in the same direction or alternately opposite to the angle α inclined.

To distribute the lubricant around the roller bearing, an uninterrupted or an interrupted circumferential annular groove may be formed in the outer surface of the outer ring, one or more of which are guided to close to the outer ring raceway on the inner circumferential surface. In this way, a metered distribution of the lubricant supply over the circumference of the rolling bearing can be achieved. If the rolling bearing is an angular ball bearing, then it is advantageous if the at least one lubricant bore opens at a distance from the contact angle of the angular contact ball bearing into or close to the outer raceway track. As a particularly favorable for the dimensioning of the diameter of the lubricant bores, depending on the size of the rolling bearing and the lubricant used a minimum diameter of G \ 7 mm to 0.5 times the groove board revealed, the groove width between 2 mm and ö.6 ~ times the outer ring width can be and the groove depth between 0.5 mm and 1, 5 times the groove width is selectable

Brief description of the drawings

The inventively embodied roller bearing is explained in more detail below in several preferred embodiments with reference to the betgefügten drawings. Show.

1 shows a cross section through part of an outer ring of a

Angular contact ball bearing along the line A-A in Figure 2, in which a lubricant bore is formed inclined in the circumferential direction and in the axial direction of the bearing:

FIG. 2 shows a partial axial section through the outer ring according to FIG. 1;

2a shows a cross section through part of an outer ring of an angular ball bearing along the line C-C in Figure 2b. in which a lubrication mitteibohfung is formed inclined only in the circumferential direction, Figure 2b is a teifweisen axial section through the outer ring according to, Figure 2a;

FIG. 3 shows a partial axial section through an angular contact ball bearing, complete with inner ring and cage-guided balls:

FIG. 4 shows a cross section through an outer ring of an angular contact ball bearing according to FIG. 1 with three lubricant bores, starting from a circumferential groove; FIG. 5 shows a cross section through an outer ring of an angular contact ball bearing according to FIG. 4 with three lubricant bores starting from three broken groove segments;

FIG. 6 shows a cross section through an outer ring of an angular contact ball bearing with four lubricant bores, of which in each case two lubricant bores are inclined in opposite directions;

FIG. 7 shows a partial axial section through an outer ring of an oblique ball bearing, similar to FIG. 2, according to a second embodiment of the course of a lubricant bore;

8 shows a teiiwetsen axial section through an outer ring accordingly

FIG. 2 according to a third embodiment;

FIG. 9 shows a partial axial section through an outer ring of an angular ball bearing according to FIG. 2 according to a fourth embodiment;

FIG. 10 shows a partial cross section through an outer ring of an angular contact ball bearing according to FIG. 2 with a rectangular lubricant groove in the outer circumferential surface;

11 shows a partial cross section through an outer ring esnes Scbräg- ball bearing according to Figure 2 with a third embodiment of a groove in an outer circumferential surface.

Detailed description of the drawings

FIG. 1 accordingly shows a cross section through a part of an outer ring 2 of a roller bearing 1 designed as an angular contact ball bearing along the line AA in FIG. 2. The outer ring 2 has a radially outer jacket surface 3 and an inner radial jacket surface 4 and an outer ring raceway 5 in the inner jacket surface 4. A lubricating oil bore 11 starts from a lubricant groove 12 arranged radially on the outside and extends at an angle α to the outer raceway 5 or to the radial straight line 20 which is perpendicular to the longitudinal axis of the rolling bearing 1. The angle α is more than 5 °, in the illustrated embodiment about 45 ° with respect to the radial straight line 20.

2, it can be seen that the groove 12 is arranged approximately centrally in the outer jacket surface 3 of the outer ring 2, and that the lubricant bore 11 is in the direction of the longitudinal axis of the rolling bearing 1 Wave your hand! ß inclined runs. The lubricant bore 1 1 opens in the Außenringiaufbahn 5 outside a not shown, during operation of the rolling bearing 1 by the interaction of Wälzkörpem 9, here in the form of Kugein. between the rolling elements 9 and the Außenringiaufbahn 5 forming pressure ellipse The Wink! ß is also ≥ 5 ° and can be up to 45 ° and more.

Depending on the size of the roller bearing 1 and the lubricant used, the diameter d of the lubricating oil bore 11 is between 0.7 mm for very small rolling bearings and 0.5 times the groove width b for larger rolling bearings. The groove width b is according to the same criteria between 2 mm and 0.8 times the outer ring width 8 _; while the groove depth t is between 0.5 mm and 1.5 times the groove width b. The lubricant bores 11 can have a circular cross section, an oval or a rectangular to square cross section and can be cylindrical, conical or offset in diameter in the axial direction. A complete rolling bearing 1 designed as an angular contact bearing is shown in a partial section in FIG are guided in a cage 10 and roll on the Außenringiaufbahn 5 and on a arranged in an outer circumferential surface 7 of an inner ring 6 inner ring raceway 8 from

In order to avoid pressure losses and Schmiermätteiverluste from the groove 12, two grooves 13 are axially formed on both sides of this groove 12 in the outer surface 3 of the outer ring: in each of which a sealing ring 14 is inserted in the form of Ö-rings. Owing to the axial inclination of the lubricant bore 11 at the angle β, it is possible to arrange the groove 12 for the lubricant approximately axially in the center of the outer ring 2, so that fewer problems in maintaining the standard edge rounding occur even with narrow bearing rings and there are no strong restrictions of tolerances and groove dimensions,

An embodiment is also possible in which the at least one lubricant bore in the outer ring 2 is oriented inclined only in the circumferential direction. 2a shows a cross section through a part of an outer ring 2 along the line C - C of FIG. 2b. It can be seen that this outer ring 2 has a lubricant bore 11b which is inclined only in the circumferential direction at an angle .alpha. An inclination of this lubricant bore 11b obliquely to the longitudinal axis of the angular contact bearing saving manufacturing costs is not provided. Figure 4 shows a complete cross section through an outer ring 2, which has a arranged in the outer circumferential surface 3, continuous circumferential groove 12. From this groove 12 go three evenly distributed over the circumference of the outer ring 2 and in the circumferential direction at about α = 45 ° inclined lubricant bores 11 which extend purely radially, or as in the Figures 2, 3,? 9 can also run inclined in the axial direction, and in the area of the inner circumferential surface 4 close to the outer ring raceway 5.

The embodiment according to FIG. 5 differs from the embodiment according to FIG. 4 only in that three circumferentially interrupted groove segments 12a, 12a ', 12a "are formed in the outer lateral surface 3a of the outer ring 2a, the three illustrated lubricant bores 11 each at one end of a groove segment 12a, 12a ', 12a "are arranged and in the region of the radially inner circumferential surface 4a: close to the outer ring raceway 5a. FIG. 6 shows an embodiment with four lubricant bores 11. 11a. starting from a continuous circumferential lubricant groove 12b in the outer circumferential surface 3b of the outer ring 2b. each in the circumferential direction in pairs opposite directions at an angle of α approximately 45 ° open in the region of the radially inner circumferential surface 4b close to the outer ring raceway 5b.

The figure ? shows a teitweisen axial section through an outer ring 15 with axially on either side of a groove 12 in circumferential grooves 13 arranged seals 14 in the form of O-rings. A lubricant bore 19 is guided by the groove 12 in the direction of a bearing skid 17 a of the outer ring 15, from where lubricant axially far from the outer ring raceway 18 and a career elevation 17 b enters the Wälziager 1.

FIG. 8 shows an arrangement, opposite to FIG. 7, of a lubricant bore 19a in an outer ring 15a which, starting from an outer circumferential surface 16a, opens in the region of a raceway elevation 17d. The embodiment 17 according to FIG. 1 is formed without a groove in the outer peripheral surface 16a, so that the lubricant element bore 19a extends directly from the outer circumferential surface 16a. It is self-evident, of course In this case, it is also possible to provide a groove, as shown in FIG. 7, in the region of the beginning of the lubricant bore 19a. The hints! The lubricant bore 19 according to FIG. 7 is approximately 40 °, while the angle β in the embodiment according to FIG. 8 is more than 50 °

The embodiment according to Figure 9 is an outer ring 15b with an outgoing from an outer circumferential surface 16b lubricant bore 19b de- _t ren inclination angle beta to the straight line 20 which is perpendicular to the longitudinal axis of the rolling bearing 1, is only about 20 °. This lubricant bore 19b is arranged so that it opens in the outer ring raceway 18 within the compression lip. The outer ring 16b has a bearing shoulder 17e and a running shoulder. web elevation 17f, as has already been explained with reference to FIGS. 7 and 8.

While in FIGS. 2, 3 and 7 the groove 12 has a circular arc shape in cross-section, the groove 12c in FIG. 10 is rectangular and the groove 12d in FIG. 11 is triangular-asymmetrical in cross-section, the rectangular shape of the groove 12c according to FIG In the direction of rotation, inclined lubricant bores 11 are particularly suitable, while the triangular groove 12d according to FIG. 11 is suitable for the lubricant bores 19. 19a, which are also inclined in the axial direction. 19b is particularly suitable

The exemplary embodiments shown all relate to an angular contact ball bearing. It will be understood, however, that the invention is not limited to angular contact ball bearings, but extends to all types of roller bearings which require a running or intermittent supply of lubricant, such as grooved ball bearings, cylinder rod bearings. Kegeiroiienlager, needle roller bearings u. like.

All the features mentioned in the preceding description of the drawings, in the claims and in the description are usable both individually and in any desired combination with one another. The invention is thus not limited to the described and claimed combinations of features, but all feature combinations are to be regarded as disclosed.

LIST OF REFERENCE NUMBERS

1 rolling bearing

2, 2a, 2b outer ring

3, 3a. 3b Outer lateral surface

4, 4a. 4b Inner lateral surface

5, 5a, 5b outer ring track

6 inner ring

7 Outer lateral surface

8! Nnenringiaufbahn

9 rolling elements

10 kafig

11, 11a, 11b lubricant bore

12 Continuous circumferential groove

12a, 12a ', 12a; Intermittent circumferential groove, groove segment

12b Continuous circumferential groove

12c groove with rectangular cross section

12d groove with triangular cross section

13 groove for sealing ring

14 sealing ring. O-ring

15, 15a, 15b outer ring

16, 16a, 18b Outer lateral surface

1? A, 17c, 17e camp shoulder

17b, 17d. 17f career overhang

18 outer ring raceway

19, 19a, 19b lubricant bore

20 Straight

b groove width

d Diameter of the lubricant bore

g pressure angle! of angular contact ball bearing

t groove depth

B outer ring width

σ angle of the lubricant bore in the circumferential direction ß Angle of the lubricant bore in the axial direction

Claims

claims

Rolling bearing (1) having an outer ring (2, 2a, 2b, 15, 15a, 15b) with an outer lateral surface (3, 3a, 3b, 16, 16a, 18b) and with an inner circumferential surface (4, 4a, 4b) of the outer ring (2, 2a, 2b, 15, 15a, 15b) formed outer ring raceway (5. 5a, 5b, 18), with an inner ring (6) with one in an outer circumferential surface (7) of the inner ring (6) formed inner raceway (8), with in the outer ring raceway (5, 5a, 5b, 18) and in the inner ring! (8) rolling rolling elements arranged (9), and with at least one in the outer ring (2, 2a, 2b, 15. 15a, 15b), from its outer circumferential surface (3, 3a, 3b, 16, 16a, 16b) to close to the outer ring raceway (5, 5a, 5b, 18) on the inner lubricant surface (11, 11a, 11b, 19, 19a, 19b), characterized in that in the outer ring (2, 2a, 2b, 15, 15a, 15b) and / or or in the inner ring (6) the at least one lubricant bore {11, 11a, 1 1b, 19, 19a. 19b) in the circumferential direction of the bearing ring (2, 2a, 2b, 15, 15a, 15b: 6) at an angle (α) of 90 °> <α> 0 ° with respect to a radial straight line (20). which is perpendicular to the longitudinal axis of the rolling bearing (1), is formed inclined.

Rolling bearing according to claim 1 _; characterized in that the angle (a) has the value α≥ 5 °.

Rolling bearing according to claim 1 or 2, characterized in that the at least one scarfing means bore (11, 11a, 19, 19a, 19b) is formed inclined in the axial direction of the roller bearing (1) at an angle (β).

Rolling bearing according to claim 3, characterized in that the hints! (ß) has a value of 5 '<ß <45 °.

Rolling bearing according to one of the preceding claims, characterized in that a plurality of lubricant bores (11.1 1a, 11b, 19, 19a, 19b) 5 are provided, which are formed in the circumferential direction in the same direction or alternately opposite at the angle (a) inclined δ. Rolling bearing according to one of the preceding claims, characterized in that in the outer circumferential surface (3, 3a, 3b, 18, 18a, 18b) there are at least one annular groove (12, 12a, 12a ', 12a ") which is broken or interrupted. is formed, from which one or more lubricant bores (11, 11a, 11b, 19, 19a, 19b) to close to the AuSenringlaufbahn (5. 5a. 5b) on the inner circumferential surface (4, 4a, 4b) are guided according to one of the preceding claims, characterized in that the at least one lubricant bore (11 11a, 11b, 19, 19a, 19b) in a designed as angular contact ball bearing roller bearing (1) at a distance to the pressure angle (g) in or close to the Außentingiaufbahn (5, 5a, 5b _: 18) opens.

8. Rolling bearing according to one of the preceding claims, characterized marked, that the diameter (d) of the lubricant bore (11, 11 a, 11 b, 19, 19 a, 19 b) depending on the size of the rolling bearing (1) and the lubricant used between 0.7 mm and 0.5 times the groove width (b), the groove width (b) is between 2 mm and 0.6 times the outer ring width (B), and the groove depth (t) between 0.5 mm and 1.5 times the groove width (b).