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EP-4741224-A1 - GEAR WHEEL ASSEMBLY, TRANSMISSION AND ADJUSTMENT DEVICE FOR A MOTOR VEHICLE

EP4741224A1EP 4741224 A1EP4741224 A1EP 4741224A1EP-4741224-A1

Abstract

Gear assembly (10) comprising a gear (14) and at least one thrust washer (30, 32) with a substantially annular thrust surface (54), wherein the gear (14) has an axis of rotation (16) and a toothing (18) rotating about the axis of rotation (16) with teeth (22) and tooth gaps (24) arranged alternately in a circumferential direction (20) about the axis of rotation (16), wherein the toothing (18) has at least one axial end face (34, 36) with a recess (38) rotating about the axis of rotation (16), wherein the at least one thrust washer (30, 32) has at least one disc projection (56) projecting radially beyond the thrust surface (54), and is arranged in the recess (38) such that the at least one disc projection (56) engages radially in each of the tooth gaps (24), and Transmission (72) with a gear assembly (10), and adjustment device for a motor vehicle, in particular for a motor vehicle seat.

Inventors

  • Fuchs, Gabriel
  • Hengstler, Manuel
  • WEINERT, JOHANNES

Assignees

  • IMS Gear SE & Co. KGaA

Dates

Publication Date
20260513
Application Date
20241111

Claims (15)

  1. Gear assembly (10) comprising a gear (14) and at least one thrust washer (30, 32) with a substantially annular thrust surface (54), wherein the gear (14) has an axis of rotation (16) and a toothing (18) rotating about the axis of rotation (16) with teeth (22) and tooth gaps (24) arranged alternately in a circumferential direction (20) about the axis of rotation (16), wherein the toothing (18) has at least one axial end face (34, 36) with a recess (38) rotating about the axis of rotation (16), characterized by the fact that the at least one thrust washer (30, 32) has at least one disc projection (56) projecting radially beyond the thrust surface (54), and is arranged in the recess (38) such that the at least one disc projection (56) engages radially in each of the tooth gaps (24).
  2. Gear assembly according to claim 1, characterized by the fact that which has at least one end face (34, 36) at least one step (48) radially limiting the recess (38).
  3. Gear assembly according to claim 2, characterized by the fact that the at least one shoulder (48) has a shoulder diameter (49), wherein the shoulder diameter (49) is smaller than a pitch circle diameter (44) of the gearing (18) and larger than a root circle diameter (46) of the gearing (18) is trained.
  4. Gear assembly according to one of claims 2 to 3, characterized by the fact that the at least one paragraph (48) is arranged to limit the recess (38) radially inwards and/or the recess (38) radially outwards.
  5. Gear assembly according to one of claims 2 to 4, characterized by the fact that the toothing (18) has a tooth height (50) and the at least one shoulder (48) has a shoulder height (52), wherein the ratio of the shoulder height (52) to the tooth height (50) is 0.05 to 0.3 and preferably 0.05 to 0.15.
  6. Gear assembly according to one of the preceding claims, characterized in that the gear (14) and the at least one thrust washer (30, 32) are exclusively positively connected to each other.
  7. Gear assembly according to one of the preceding claims, characterized in that a projection contour (64) of the at least one disc projection (56) is formed at least sectionally mathematically similar to a gap contour (66) of one of the tooth gaps (24).
  8. Gear assembly according to one of the preceding claims, characterized in that which has at least one thrust washer (30, 32) and several washer projections (56).
  9. Gear assembly according to one of the preceding claims, characterized in that the gear (14) has at least one radial bearing seat (68) arranged axially adjacent to the toothing (18).
  10. Gear assembly according to one of the preceding claims, characterized in that the gear (14) is designed as a spindle nut (12).
  11. Gear assembly according to one of the preceding claims, characterized in that a first thrust washer (30) of the at least one thrust washer (30, 32) is arranged on a first end face (34) of the at least one end face (34, 36) and a second thrust washer (32) of the at least one thrust washer (30, 32) is arranged on a second end face (36) of the at least one end face (34, 36), wherein the second end face (36) is arranged axially opposite the first end face (34).
  12. Transmission (72), in particular for an adjustment device for a motor vehicle, comprising a gear assembly (10) according to one of the preceding claims.
  13. Gearbox according to claim 12, characterized by the fact that the gearbox (72) has at least one plain bearing (76), wherein the at least one plain bearing (76) has an axial bearing section (78) which is arranged axially adjacent to the thrust surface (54) of the at least one thrust washer (30, 32).
  14. Transmission according to one of claims 12 to 13, wherein the gear assembly is designed according to claim 9, characterized by the fact that the at least one sliding bearing (76) has a radial bearing section (82) formed at right angles to the axial bearing section (78), wherein the radial bearing section (82) is arranged adjacent to the radial bearing seat (68), and wherein • an axial inner diameter (84) of the axial bearing section (78) is greater than or equal to a thrust surface inner diameter (86) of the thrust surface (54), and/or • an axial outer diameter (88) of the axial bearing section (78) is less than or equal to a thrust surface outer diameter (90) of the thrust surface (54).
  15. Adjustment device for a motor vehicle, in particular for a motor vehicle seat, with a transmission (72) according to one of claims 12 to 14.

Description

The invention relates to a gear assembly, a transmission with such a gear assembly and an adjustment device for a motor vehicle. For the electrically driven longitudinal adjustment of seats in motor vehicles, seat longitudinal adjustment devices are frequently used. These devices often incorporate a spindle drive, which transmits speed and torque between a worm gear and a spindle. A spindle nut is mounted on the spindle, which in turn has a toothed ring with external teeth that meshes with the worm gear. Plain bearings are typically used to support the spindle nut, mounted on bearing seats located axially adjacent to the external gearing. Particularly with helical external gearing, it is necessary to support the spindle nut appropriately in the axial direction to withstand the resulting axial forces. Therefore, an axial bearing surface must be provided on the spindle nut to form a sliding contact with a plain bearing. To provide such a bearing surface on the axial end faces of the external gearing, it is state of the art to cover the axially open external gearing with a thrust washer. For the sliding contact between the plain bearing and the thrust washer to be defined, the thrust washer must be The thrust washer must be arranged in a rotationally fixed manner on the spindle nut. Various solutions are known to secure the thrust washer against rotation relative to the spindle nut. So the DE 10 2013 207 665 A1 The idea is to press the thrust washer onto the spindle nut. However, a disadvantage of this method is that pressing it on can lead to chip removal and deformation of the thrust washer. Both of these can result in premature gearbox failure. From the KR 101 920 222 B1 It is known to provide a thrust washer with an axial projection that can engage axially between two teeth of the external gear. A disadvantage of this solution is that the manufacturing of the thrust washer is relatively complex. The one in DE 103 62 040 B4 The thrust washer shown has a radial projection which, after the thrust washer is placed on the spindle nut, is bent in the axial direction, thus allowing it to engage axially between two teeth of the external gearing. A disadvantage of this system has been found to be that an additional manufacturing step is required to bend the radial projection when placing the thrust washer on the spindle nut. The invention is therefore based on the objective of providing a gear assembly in which the thrust washer can be easily and securely arranged on the face of the gear teeth. The invention is further based on the objective of providing a corresponding transmission and a corresponding adjustment device for a motor vehicle. The problems are solved according to the invention by a gear assembly with the features of claim 1, a transmission with the features of claim 12 and an adjusting device with the features of claim 15. Advantageous embodiments and further developments of the invention are specified in the dependent claims. A gear assembly according to the invention comprises a gear and at least one thrust washer with a substantially annular bearing surface, wherein the gear has an axis of rotation and a toothed section circumferentially around the axis of rotation, with teeth and tooth gaps arranged alternately in a circumferential direction around the axis of rotation, wherein the toothed section has at least one axial end face with a recess circumferentially around the axis of rotation. Each of the teeth can thus have a first section and a second section axially offset from the first section. The toothed section is preferably radially bounded on one side by a root diameter and on the other side by a tip diameter. The recess can thus be intersected by the tooth gaps. Preferably, the toothed section is designed as an external toothed section, such that the toothed section is preferably bounded radially outwards by the tip diameter and radially inwards by the root diameter. Unless otherwise specified, the terms "radial" and "axial" here and in the following refer to the axis of rotation. According to the invention, the at least one thrust washer has at least one radially projecting disc projection extending beyond the thrust surface and is arranged in the recess such that the at least one disc projection engages radially in each of the tooth gaps. This allows the At least one thrust washer should be easy to manufacture and secured against rotation on the gear in a single manufacturing step. The at least one thrust washer can thus be arranged on the gear such that the at least one washer projection bears against a tooth flank radially adjacent to the recess. Therefore, no additional locking structure, such as a locking groove (especially an axial one), is required on the gear side. Preferably, the at least one washer projection engages exclusively radially in one of the tooth gaps. The description of the thrust surface as essentially annular indicates that, in particular, a relief groove of the at