Rolling bearings, as well as motor vehicles with such rolling bearings

Abstract

The invention relates to a rolling bearing (1) with an outer bearing ring (3), an inner bearing ring (4) arranged coaxially to the outer bearing ring (3), and rolling elements (5) arranged radially between the bearing rings (3, 4). The rolling bearing (1) comprises a corrosion protection device (2) which has a corrosion inhibitor reservoir (10) and a channel device (14). A corrosion inhibitor channel (16) of the channel device (10) opens into the corrosion inhibitor reservoir (10) on one side and onto an outer bearing surface (15) on the other. This provides a simple solution for preventing fretting corrosion between the rolling bearing (1) and its bearing seat. The invention also proposes a motor vehicle that incorporates such a rolling bearing (1).

Description

[0001] The present invention relates to a rolling bearing and a motor vehicle having such a rolling bearing.

[0002] In a conventional electric machine, the rotor shaft is mounted to the machine's housing by means of a rolling bearing. However, it can happen that the outer race of the rolling bearing rotates in an undesirable manner relative to the bearing seat in the housing; this is known as creep. Such micro-movements—that is, creep—lead to material abrasion and consequently to rust and material buildup between the bearing seat and the outer race. This can lead to bearing seizure and ultimately to the failure of the electric machine.

[0003] Prior art attempts to completely prevent creep. For this purpose, so-called creep-free bearings are known from the prior art, for example from US 2010 158 424 A1 or WO 2016 123 196 A1. Non-metallic O-rings are used between the outer bearing ring and the bearing seat, providing radial spacing between the bearing seat and the outer bearing ring. These non-metallic O-rings are made of materials such as plastic or resin and are held in circumferential grooves. However, these O-rings make mounting the bearing in its corresponding bearing seat more difficult, as the O-rings can be damaged during axial insertion / pressing. Furthermore, the O-rings can wear down during operation, thus losing their effectiveness.The faster aging of O-ring material compared to metal is also problematic, as substances from the O-rings can outgas over the bearing's service life and damage other components of the bearing and / or the machine housing the bearing. WO 2007 087 701 A1 proposes connecting the outer bearing ring and the bearing seat, or the inner bearing ring and the shaft, to prevent rotation using an anti-creep ball. It is clear that achieving a creep-free shaft bearing currently requires considerable effort.

[0004] The object of the present invention is to create the simplest possible solution to avoid fretting corrosion between the bearing and the bearing seat.

[0005] This problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the subclaims, the description, and the figures. Features, advantages, and possible embodiments presented in the description for one of the subject matter of the independent claims are to be regarded, across categories and embodiments, at least analogously as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the subclaims.

[0006] According to the invention, a rolling bearing and a machine comprising such a rolling bearing are proposed. The machine is, in particular, a motor vehicle. In a further embodiment of the motor vehicle, it comprises an electric traction motor. Accordingly, the motor vehicle is, in particular, a purely or hybrid-electrically powered motor vehicle, wherein the electric traction motor incorporates the rolling bearing as part of a rotor shaft bearing. The machine can equally well be another type of machine, in any case, a machine in which a shaft is supported by means of a rolling bearing.

[0007] The rolling bearing has an outer ring and an inner ring arranged coaxially with respect to a bearing axis. The rolling bearing can be designed as a pure radial bearing, a pure axial bearing, or a hybrid design. In its intended installation position, i.e., in the machine on which the rolling bearing is mounted, the rolling bearing sits in a bearing seat of the machine, with the outer ring, for example, pressed into the bearing seat. The rolling elements of the bearing are arranged radially between the outer and inner rings and are configured to roll on the outer circumferential side of the inner ring and on the inner circumferential side of the outer ring during relative rotation of the bearing rings. Although cylindrical rollers, needle rollers, tapered rollers, barrel rollers, toroidal rollers, etc., are suitable as rolling elements for the rolling bearing according to the invention, for the sake of simplicity, only balls are referred to here as rolling elements.To prevent rust formation between the outer ring and the bearing seat when the rolling bearing is installed in its intended position, the rolling bearing incorporates an integrated rust protection device. This device comprises a rust inhibitor reservoir and a channel system with a rust inhibitor channel that opens into the reservoir and onto an outer bearing surface. The rust inhibitor reservoir can be filled with a preferably pasty rust inhibitor – such as a grease, oil, wax, petroleum jelly, etc. – or is already filled when the bearing is ready for operation. In particular, a bearing lubricant, which the rolling bearing already contains independently of the rust protection device to ensure lubrication, is used as the rust inhibitor.

[0008] During operation of the rolling bearing or the machine containing the rolling bearing, the rust inhibitor flows through the channel system from the rust inhibitor reservoir and thus onto the outer surface of the rolling bearing, in particular onto an outer circumferential bearing seat surface of the outer ring of the bearing. This prevents corrosion between the rolling bearing and its seat. Even if the rolling bearing were to rotate within the bearing seat, no material abrasion would occur, and consequently, no material would accumulate in the annular gap between the rolling bearing and the bearing seat. In this way, the proper functioning of the rolling bearing is ensured with particularly simple means. A specific position, a flowable cross-section, a certain fill level of the rust inhibitor reservoir, or a certain flowability are not required.The viscosity of the rust inhibitor and / or the number of rust inhibitor channels of the channel system are / are selected such that, during operation of the rolling bearing, a predetermined amount of rust inhibitor per unit of time escapes from the rust inhibitor reservoir to the outer surface of the rolling bearing.

[0009] In another possible embodiment, the corrosion inhibitor reservoir has an outer ring tank integrated into the outer bearing ring. Alternatively or additionally, the corrosion inhibitor reservoir has an inner ring tank integrated into the inner bearing ring. The respective ring tank is, for example, designed as a cavity within the material body of the corresponding bearing ring. The respective ring tank can be continuous along the circumference of the corresponding bearing ring or have two or more ring tank chambers along the circumference. Furthermore, the respective ring tank can have two or more ring tank sections along the axial direction of the corresponding bearing ring, which in turn can be continuous along the circumference or have ring tank chambers. Thanks to the respective ring tank, the corrosion inhibitor can be stored inside the rolling bearing particularly efficiently without increasing the axial and radial installation space.

[0010] In a further possible configuration, the channel system has one or more of the following corrosion protection channels per ring tank or ring tank section: - an axial channel penetrating the corresponding bearing ring from the corresponding annular tank - a radial channel radially penetrating the corresponding bearing ring from the corresponding annular tank, - an inclined channel penetrating the corresponding bearing ring from the corresponding annular tank at an angle, - a mixing channel that penetrates the corresponding bearing ring axially, radially and / or obliquely from the corresponding annular tank.

[0011] Each corrosion inhibitor channel can have one or more odd-numbered sections. Due to the design of these corrosion inhibitor channels, the points on the outer surface of the rolling bearing where the corrosion inhibitor exits the corrosion inhibitor reservoir can be specified particularly efficiently during the design and construction of the rolling bearing.

[0012] According to a possible further development, the rolling bearing has a pair of sealing discs by means of which a rolling element chamber of the rolling bearing is axially sealed on both sides against corrosion inhibitor. The rolling elements are arranged between the bearing rings in the rolling element chamber, and the corrosion inhibitor reservoir forms the rolling element chamber as a tank. In this case, at least one channel of the channel assembly opens into the rolling element chamber, so that during operation of the rolling bearing, corrosion inhibitor from the rolling element chamber or from the rolling element chamber tank can reach the outer surface of the rolling bearing. The pair of sealing discs thus advantageously has a dual function: firstly, its sealing discs delimit the rolling element chamber tank, and secondly, the sealing discs act as a protective element against the ingress of foreign matter into the rolling element chamber. Furthermore, the rolling element chamber is advantageously used to store as much corrosion inhibitor as possible in the rolling bearing.

[0013] In a possible further development of the rolling element reservoir, the channel assembly includes an outer ring channel that penetrates the bearing's outer ring and opens into the rolling element reservoir on one side and onto the outer circumferential bearing seat surface of the rolling bearing on the other. Alternatively or additionally, the channel assembly in conjunction with the rolling element reservoir includes a sealing disc channel that penetrates one of the sealing discs of the sealing disc pair and opens into the rolling element reservoir on one side and onto an outer sealing disc surface of the rolling bearing on the other. Analogous to the respective corrosion inhibitor channel for the ring reservoirs or the ring reservoir itself, the respective outer ring channel or inner ring channel can be designed as an axial, radial, inclined, or mixed-shape channel. The corrosion inhibitor can exit the rolling element reservoir particularly efficiently via the outer ring channel and / or the sealing disc channel.

[0014] Another possible embodiment provides that the rust protection device has a lateral filling coupling that communicates with the rust inhibitor reservoir, to which a corresponding coupling of a rust inhibitor dispenser can be connected in order to fill the rust inhibitor reservoir with rust inhibitor. This allows for particularly simple refilling of rust inhibitor – for example, during maintenance or an overhaul of the machine containing the rolling bearing.

[0015] Further features of the invention may become apparent from the claims, the drawing, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the drawing alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0016] The drawing shows in the with Fig. Figure 1, the single figure, shows a schematic and sectional view of a rolling bearing 1, which has a corrosion or rust protection device 2. Fig. Elements with the same reference numerals are identical and functionally equivalent. A motor vehicle featuring the rolling bearing 1 is not shown in the drawing. In the present example, the motor vehicle is designed as a purely or hybrid-electric vehicle and accordingly has an electric traction motor. Its rotor shaft is supported on a housing of the electric traction motor by means of the rolling bearing 1. In other words, the rotor shaft bearing of the traction motor includes the rolling bearing 1.

[0017] The rolling bearing 1 has an outer bearing ring 3 and a coaxially arranged inner bearing ring 4, as well as rolling elements 5, in this case balls. The balls or rolling elements 5 are located in a rolling element chamber 6, which is bounded in the radial direction r of the rolling bearing 1 on one side by the outer bearing ring 3 and on the other side by the inner bearing ring 4. This means that the rolling elements 5 are arranged radially between the outer bearing ring 3 and the inner bearing ring 4 and, according to the bearing function inherent in the rolling bearing 1, are configured to roll on the outer circumference of the inner bearing ring 4 and on the inner circumference of the outer bearing ring 3 during a relative rotation of the bearing rings 3 and 4. Fig. Figure 1 also shows that the rolling bearing 1 has a rolling element cage 7, designed here as a ball cage, by means of which the rolling elements 5 of the rolling bearing 1 are guided along the axial direction x of the rolling bearing. In addition, the rolling bearing in the example described here has a pair of sealing washers comprising two lateral sealing washers 8, 9.

[0018] The rust protection device 2 comprises a rust inhibitor reservoir 10, which is filled with a rust inhibitor (not shown), for example, a grease. In this example, the rust inhibitor reservoir 10 has an outer ring tank 11, an inner ring tank 12, and a rolling element chamber tank 13, which are explained in more detail below.

[0019] The outer ring tank 11 is designed here as a cavern arrangement integrated or embedded in the outer bearing ring 3 and can be continuous along one circumferential direction of the rolling bearing 1 or the outer bearing ring 3. Alternatively, the outer ring tank 11 can have two or more outer ring tank chambers (not shown) along the circumferential direction. In this case, the outer ring tank 11 comprises two or more outer ring tank sections 11a, which are arranged separately from one another along the axial direction x of the rolling bearing 1. Each outer ring tank section 11a can itself be designed with or without outer ring tank chambers. The inner ring tank 12 is designed here as a cavern arrangement integrated or embedded in the inner bearing ring 4 and can be continuous along the circumferential direction of the rolling bearing 1 or the inner bearing ring 3.Alternatively, the inner annular tank 12 can have two or more inner annular tank chambers (not shown) along its circumference. In this case, the inner annular tank 12 comprises two or more inner annular tank sections 12a, which are arranged separately from one another along the axial direction x of the rolling bearing 1. Each inner annular tank section 12a can itself be configured with or without inner annular tank chambers.

[0020] The corrosion protection device 2 has a channel arrangement 14 by means of which the corrosion protection reservoir 10 and a rolling bearing outer surface 15 are fluidically connected to each other such that, during operation of the rolling bearing 1, corrosion protection fluid from the corrosion protection reservoir 10 reaches the rolling bearing outer surface 15 via the channel arrangement 14. For this purpose, the channel arrangement 14 has a corrosion protection channel 16 – in this case, several corrosion protection channels 16 – wherein the respective corrosion protection channel 16 opens on one side into the corrosion protection reservoir 10, i.e., into one of the corrosion protection tanks 11, 12, 13, and on the other side into a rolling bearing outer surface 15, for example, as is the case in Fig. 1 is shown schematically. As from Fig. As can be further seen from Figure 1, the channel arrangement 14 in this case has one or more corrosion protection channels 16 for each annular tank 11, 12, and in particular for each annular tank section 11a, 12a, wherein the respective corrosion protection channel 16 can be configured as an axial channel 17 penetrating the corresponding bearing ring 3, 4 axially, as a radial channel 18 penetrating the corresponding bearing ring 3, 4 radially, or as an oblique channel 19 penetrating the corresponding bearing ring 3, 4 obliquely. In addition, the respective corrosion protection channel 16 can be configured as a hybrid channel 20 penetrating the corresponding bearing ring 3, 4 axially, radially, and / or obliquely.

[0021] By means of the sealing disc pair 8, 9, the rolling element chamber 6 is laterally sealed on both sides, i.e., along the axial direction x, with corrosion protection material, so that the rolling element chamber 6 is radially bounded by the bearing rings 3, 4 and laterally / axially by the sealing discs 8, 9. Thus, the rolling element chamber 6 forms the rolling element chamber tank 13. For this purpose, the channel arrangement 14 has at least one further corrosion protection channel 16, namely an outer ring channel 21, or in this case, a plurality of outer ring channels 21. The respective outer ring channel 21 - see Fig. 1 - opens on one side into the rolling element chamber tank 13 and on the other side at the rolling bearing outer surface 15. It is to be understood that the respective outer ring channel 21, analogous to the corrosion protection channels 16, which connect the ring tanks 11, 12 with the rolling bearing outer surface 15, can be designed as an axial outer ring channel (not shown), radial outer ring channel 22, slant outer ring channel 23 or mixed shape channel 24.

[0022] Furthermore, the channel assembly 14 of the rolling bearing 1, according to the present example, has an additional corrosion protection channel 16, namely a sealing washer channel 25. The sealing washer channel 25 penetrates one of the sealing washers 8, 9 and thus opens on one side into the rolling element chamber 13 and on the other side onto an outer sealing washer surface 26 of the rolling bearing 1. In this example, the sealing washers 8, 9 each have a sealing washer channel 25, although it is conceivable that each sealing washer 8, 9 has two or more sealing washer channels 25. The respective sealing washer channel 25 can be designed as an axial sealing washer channel 27 or as an inclined sealing washer channel 28, as is shown by way of example in Fig. 1 is shown.

[0023] Two or more outer ring tank parts 11a and / or two or more inner ring tank parts 12a can be connected to each other by means of a connecting channel 29, so that rust protection agent can pass from one of the connected ring tank parts 11a, 12a to the other of the ring tank parts 11a, 12a.

[0024] During operation of the rolling bearing 1 or the motor vehicle containing the rolling bearing 1, the rust inhibitor flows from the rust inhibitor tanks 11, 12, 13 and into the associated rust inhibitor channels 16 to exit the rust inhibitor channels 16 at the outer surface 15 of the rolling bearing. In this way, the rust inhibitor stored in the rust inhibitor reservoir 10 reaches the outer surface 15 of the rolling bearing via the channel assembly 14, thus reducing, and ideally preventing, material abrasion between the rolling bearing 1 and a bearing seat in which the rolling bearing 1 is installed in its intended position.

[0025] One way to fill the rolling bearing 1 or the rust inhibitor reservoir 10 with rust inhibitor, particularly when the rolling bearing 1 is mounted and in its installed position, is provided, according to the present example, by a filling coupling 30 of the rolling bearing 1, which communicates fluidically with the rust inhibitor reservoir 10. The filling coupling 30 is configured to be fluidically coupled with a corresponding coupling 31 of a rust inhibitor dispenser (not shown, for example, a grease gun).

[0026] The rolling bearing 1 and the motor vehicle each demonstrate a way in which fretting corrosion between the bearing and the bearing seat can be avoided particularly efficiently and with simple means. Reference symbol list 1 rolling bearing 2. Rust protection device 3 outer bearing ring 4 inner bearing ring 5 rolling elements 6 rolling element space 7 rolling element cage 8 Sealing washer 9 Sealing washer 10 Rust protection reservoir 11 Outer ring tank 11a Outer ring tank part 12 inner ring tank 12a Inner ring tank part 13 rolling element chamber tank 14 Channel equipment 15 Rolling bearing outer surface 16 Rust protection channel 17 Axial canal 18 Radial canal 19 inclined channel 20 Mixing mold channel 21 Outer ring channel 22 Radial outer ring channel 23 Slanted outer ring channel 24 Mixing channel 25 Sealing disc channel 26 Sealing disc outer surface 27 Axial sealing disc channel 28 Angled sealing disc channel 29 Connection channel 30 filling coupling 31 Coupling of a rust inhibitor dispenser QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 2010 158 424 A1

[0003] WO 2016 123 196 A1

[0003] WO 2007 087 701 A1

[0003]

Claims

[1] Rolling bearing (1) with - a bearing outer ring (3), - a bearing inner ring (4) arranged coaxially to the bearing outer ring (3), - rolling elements (5) arranged radially between the bearing rings (3, 4), - a rust protection device (2), comprising: - a rust inhibitor reservoir (10), - a channel device (14) with a rust protection agent channel (16) which opens on the one hand into the rust protection agent reservoir (10) and on the other hand into a rolling bearing outer surface (15). [2] Rolling bearing (1) according to claim 1, characterized by that the rust inhibitor reservoir (10) - has an outer ring tank (11) which is integrated into the bearing outer ring (3), and / or - an inner ring tank (12) which is integrated into the bearing inner ring (4). [3] Rolling bearing (1) according to claim 2, characterized bythat the channel device (14) has one or more of the following rust protection agent channels (16) for each ring tank (11, 12): - an axial channel (17) axially penetrating the corresponding bearing ring (3, 4) from the corresponding ring tank (11, 12), - a radial channel (18) radially penetrating the corresponding bearing ring (3, 4) from the corresponding ring tank (11, 12), - an inclined channel (19) penetrating the corresponding bearing ring (3, 4) at an angle from the corresponding ring tank (11, 12), - a mixed-form channel (20) which penetrates the corresponding bearing ring (3, 4) axially, radially and / or obliquely from the corresponding ring tank (11, 12). [4] Rolling bearing (1) according to one of the preceding claims, characterized bya pair of sealing discs, by means of which a rolling element chamber (6), in which the rolling elements (5) are arranged between the bearing rings (3, 4), is sealed axially on both sides in a rust-proof manner, wherein the rust-proof reservoir (10) has the rolling element chamber (6) as a rolling element chamber tank (13). [5] Rolling bearing (1) according to claim 4, characterized by that the channel device (14) has an outer ring channel (21) which penetrates the bearing outer ring (3) and thereby opens on the one hand into the rolling element chamber tank (13) and on the other hand at an outer peripheral bearing seat surface (15) of the rolling bearing (1). [6] Rolling bearing (1) according to claim 4 or 5, characterized by that the channel device (14) has a sealing disc channel (25) which penetrates one of the sealing discs (8, 9) of the sealing disc pair and thereby opens on the one hand into the rolling element chamber tank (13) and on the other hand at a sealing disc outer surface (26) of the rolling bearing (1). [7] Rolling bearing (1) according to one of the preceding claims, characterized by that the rust protection device (2) has a lateral filling coupling (30) communicating with the rust protection agent reservoir (10), to which a corresponding coupling (31) of a rust protection agent dispenser can be connected in order to fill the rust protection agent reservoir (10) with rust protection agent. [8] Motor vehicle with a rolling bearing (1) designed according to one of claims 1 to 7. [9] Motor vehicle according to claim 8, characterized by that an electric traction machine of the motor vehicle has the rolling bearing (1) as part of a rotor shaft bearing.

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