Transmission drive unit having a self-locking device

• US 8,823,228 B2
• Filed: 06/23/2009
• Issued: 09/02/2014
• Est. Priority Date: 07/04/2008
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Mili, Tarek, Lauk, Detlef, Merkelbach, Uwe
• Primary Examiner(s): Leung, Quyen
• Assistant Examiner(s): DESAI, NAISHADH N
• Application Number:
  US13/002,534
• Publication Number:
  US 20110221291A1
• Time in Patent Office: 1,897 Days
• Field of Search: 310/77, 310/83, 310/89
• US Class Current: 310/83
• CPC Class Codes: E05F 11/505 for vehicle windows
• CPC Class Codes: E05Y 2201/49 Wrap springs
• CPC Class Codes: E05Y 2900/55 Windows
• CPC Class Codes: F16H 1/16 comprising worm and worm-wheel
• CPC Class Codes: H02K 1/17 Stator cores with permanent magnets
• CPC Class Codes: H02K 7/102 with friction brakes
• CPC Class Codes: H02K 7/1166 comprising worm and worm-wheel structural association with bearings specially adapted for worm gear drives H02K7/081

Abstract

Transmission drive unit (10), in particular for adjusting movable parts in the motor vehicle, having a drive motor (12) and a transmission (14) which is driven thereby, wherein the transmission (14) has an output element (70) and a self-locking device (60) with a locking element (63, 55), and the locking element locks the transmission (12) with respect to torques which are applied to the transmission (12) by the output element (70), wherein the transmission (12) with its transmission toothing (47) and a motor shaft bearing (32, 28) is designed to have optimized efficiency and minimal friction, and the drive motor (12) has, as an exciter magnet, a sleeve-shaped annular magnet (18) which is arranged in a pole pot (16) which forms a magnetic return.

Claims

1. A transmission drive unit (10), comprising:

a drive motor (12); and

a transmission (14) which is driven by the drive motor, the transmission (14) having an output element (70) and a self-locking device (60) with a locking element (62, 55), and the locking element (62, 55) locking the transmission (12) for torques which are introduced into the transmission (12) by the output element (70),

characterized in that the transmission (12) is configured with transmission toothing (47) and a motor shaft bearing (32, 28) in a manner which is optimized with respect to the degree of efficiency with minimum friction, and the drive motor (12) has, as an exciter magnet, a sleeve-shaped toric magnet (18) which is arranged in a pole pot (16) which forms a magnetic yoke,

characterized in that a drive shaft (22) is mounted in the pole pot (16) by means of a sliding bearing (28), which is mounted in the transmission housing (36) by means of a ball bearing (32), and

characterized in that the ball bearing (32) is positioned approximately in a central region of the drive shaft (22), and the drive shaft (22) is supported in the transmission housing (36) and in the pole pot (16) only in an axial direction (23) as a fixed bearing formed by the ball bearing (32).

2. The transmission drive unit (10) as claimed in claim 1, characterized in that the toric magnet (18) has two or more magnetic poles (19) in a circumferential direction.

3. The transmission drive unit (10) as claimed in claim 1, characterized in that the toric magnet (18) has a radial wall thickness (102) of between 0.5 and 3 mm and/or a ratio of the external diameter (100) to the wall thickness (102) of between 15:

1 and 40;

1.

4. The transmission drive unit (10) as claimed in claim 1, characterized in that the toric magnet (18) is configured as a high-energy magnet and contains rare earth elements.

5. The transmission drive unit (10) as claimed in claim 1, characterized in that the pole pot (16) is configured as a deep drawn part with a circular external diameter (101) of approximately from 25 to 33 mm and has a radial wall thickness (103) of from 1 to 2 mm.

6. The transmission drive unit (10) as claimed in claim 1, characterized in that the drive motor (12) has a rotor with a stack of laminations (20) for the electric wire winding (24), the laminations (21) having a material thickness in the axial direction (23) of less than 1.0 mm.

7. The transmission drive unit (10) as claimed in claim 1, characterized in that the transmission (14) is configured as a worm gear (14) worm toothing (47) having a reduced engagement angle of, in particular, from 4°

to 8° and

a coefficient of friction of approximately 0.025.

8. The transmission drive unit (10) as claimed in claim 1, characterized in that the drive shaft (22) is mounted in the transmission housing (36) and the pole housing (16) in the axial direction (23) exclusively by the ball bearing (32) which is configured as a locating bearing.

9. The transmission drive unit (10) as claimed in claim 1, characterized in that the diameter (44) of the drive shaft (22) is between 5 and 7 mm and the worm (40) is roll formed onto the drive shaft (22) and has a greater external diameter (42) than the diameter (44) of the drive shaft (22).

10. The transmission drive unit (10) as claimed in claim 1, characterized in that the transmission (14) has a worm gear (46) which is mounted on a bearing pin (49) or bearing dome (48) made from plastic.

11. The transmission drive unit (10) as claimed in claim 1, characterized in that hammer brushes (85) extend in the axial direction (23) on a brush carrier (82) which is arranged in a circularly annular manner around the drive shaft (22), the hammer brushes (85) being arranged offset by approximately 90°

with regard to the circumferential direction.

13. The transmission drive unit (10) as claimed in claim 1, characterized in that the locking element (62, 55) is configured as a wrap spring (55) which is arranged, radially, between the worm gear (46) and the transmission housing (36).

15. The transmission drive unit (10) as claimed in claim 1, characterized in that the toric magnet (18) has exactly four magnetic poles (19) in the circumferential direction.

16. The transmission drive unit (10) as claimed in claim 1, characterized in that the toric magnet (18) has a radial wall thickness (102) of between 0.5 and 1.5 mm, and/or a ratio of the external diameter (100) to the wall thickness (102) of between 15:

1 and 40;

1.

17. The transmission drive unit (10) as claimed in claim 1, characterized in that the toric magnet (18) is configured as a high-energy magnet and contains rare earth elements, and is formed from NdFeB which is sintered or bonded in plastic.

18. The transmission drive unit (10) as claimed in claim 1, characterized in that a drive shaft (22) is mounted in the pole pot (16) by means of a sliding bearing (28), which is produced as a sintered bronze bush (29), and is mounted in the transmission housing (36) by means of a ball bearing (32).

12. A transmission drive unit (10), comprising:

a drive motor (12); and

a transmission (14) which is driven by the drive motor, the transmission (14) having an output element (70) and a self-locking device (60) with a locking element (62, 55), and the locking element (62, 55) locking the transmission (12) for torques which are introduced into the transmission (12) by the output element (70),

characterized in that the transmission (12) is configured with transmission toothing (47) and a motor shaft bearing (32, 28) in a manner which is optimized with respect to the degree of efficiency with minimum friction, and the drive motor (12) has, as an exciter magnet, a sleeve-shaped toric magnet (18) which is arranged in a pole pot (16) which forms a magnetic yoke,

characterized in that the pole pot (16) is connected to the transmission housing (36) by means of plastic material forming (94), and is pushed onto a sleeve-shaped axial projection (38) of the transmission housing (36).

14. A transmission drive unit (10), comprising:

a drive motor (12); and

a transmission (14) which is driven by the drive motor, the transmission (14) having an output element (70) and a self-locking device (60) with a locking element (62, 55), and the locking element (62, 55) locking the transmission (12) for torques which are introduced into the transmission (12) by the output element (70),

characterized in that the transmission (12) is configured with transmission toothing (47) and a motor shaft bearing (32, 28) in a manner which is optimized with respect to the degree of efficiency with minimum friction, and the drive motor (12) has, as an exciter magnet, a sleeve-shaped toric magnet (18) which is arranged in a pole pot (16) which forms a magnetic yoke,

characterized in that a wrap spring (55) of the self-locking device (60) comes to bear with its external diameter (42) against the inner wall (52) of the transmission housing (36) and is connected, directly, by way of its ends (56) to the worm gear (46) and the output element (70).

19. A transmission drive unit (10), comprising:

a drive motor (12); and

a transmission (14) which is driven by the drive motor, the transmission (14) having an output element (70) and a self-locking device (60) with a locking element (62, 55), and the locking element (62, 55) locking the transmission (12) for torques which are introduced into the transmission (12) by the output element (70),

characterized in that the transmission (12) is configured with transmission toothing (47) and a motor shaft bearing (32, 28) in a manner which is optimized with respect to the degree of efficiency with minimum friction, and the drive motor (12) has, as an exciter magnet, a sleeve-shaped toric magnet (18) which is arranged in a pole pot (16) which forms a magnetic yoke,

characterized in that the diameter (44) of the drive shaft (22) is 6 mm and the worm (40) is roll formed onto the drive shaft (22) and has a greater external diameter (42) than the diameter (44) of the drive shaft (22).