Drive Unit For Actuator Drive Including An Electric Motor And Actuator Drive

• US 20130104682A1
• Filed: 10/31/2012
• Published: 05/02/2013
• Est. Priority Date: 10/31/2011
• Status: Active Grant

• Current Assignee: Minebea Mitsumi, Inc.
• Original Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Inventors: SCHNEIDER, Helmut
• Granted Patent: US 9,163,700 B2
• Time in Patent Office: Days
• US Class Current: 74/421.A
• CPC Class Codes: F16H 1/20 involving more than two intermeshing members
• CPC Class Codes: F16H 1/22 with a plurality of driving or driven shafts; with arrangements for dividing torque between two or more intermediate shafts
• CPC Class Codes: F16H 2057/02082 for application in vehicles other than propelling, e.g. adjustment of parts
• CPC Class Codes: F16H 57/021 Shaft support structures, e.g. partition walls, bearing eyes, casing walls or covers with bearings
• CPC Class Codes: H02K 1/278 Surface mounted magnets; Inset magnets
• CPC Class Codes: H02K 7/116 with gears
• CPC Class Codes: Y10T 74/19684 Motor and gearing

Abstract

A drive unit for an actuator having an electric motor, wherein the drive unit comprises a gear train having at least a first gear stage and a last gear stage, wherein the gear train realizes a transmission ratio of greater than one from the electric motor to an output wheel, wherein each gear stage is formed by a gear drive and wherein in the last gear stage, one gear wheel or alternatively two gear wheels connected in parallel are provided that each mesh with an upstream gear wheel of the gear train and with the output wheel, so as to transmit the torque acting on the last gear stage to this stage via the one gear wheel or alternatively distributed over the two gear wheels connected in parallel, wherein the drive unit is accommodated in a housing of the actuator that has at least a first and a second bearing support for the gear wheels of the last gear stage, and to form this last gear stage, the two bearing supports are fitted with the one gear wheel or alternatively with the two gear wheels connected in parallel.

Claims

1. A drive unit for an actuator having an electric motor,

wherein the drive unit (1) comprises a gear train having at least a first gear stage and a last gear stage, wherein the gear train realizes a transmission ratio of greater than one from the electric motor to an output wheel (5′

″

, 81),

wherein each gear stage is formed by a gear drive and

wherein in the last gear stage one gear wheel (53″

) or alternatively two gear wheels (83, 83′

) connected in parallel are provided that each mesh with an upstream gear wheel (53′

, 79b) of the gear train and with the output wheel (53′

″

;

81), so as to transmit the torque acting on the last gear stage to this stage via the one gear wheel (53″

) or alternatively distributed over the two gear wheels (83, 83′

) connected in parallel,

wherein the drive unit (1) is accommodated in a housing (11) of the actuator that has at least a first and a second bearing support (59) for the gear wheels of the last gear stage, and to form this last gear stage, the two bearing supports (59) are fitted with the one gear wheel (53″

) or alternatively with the two gear wheels (83, 83′

) connected in parallel.

2. A drive unit according to claim 1 that is configured such that the output wheel (53′

″

, 81) rotates more slowly than the gear wheel (53″

) or the gear wheels (83, 83′

) respectively of the last gear stage.

3. A drive unit according to claim 1, wherein the gear wheels form a spur gear unit.

4. A drive unit according to claim 1, wherein the two gear wheels (83, 83′

) connected in parallel of the last gear stage are identical.

5. A drive unit according to claim 1, wherein the housing (11) of the actuator is designed to receive the entire gear train and to position the gear wheels of the gear stages with respect to one another and with respect to the electric motor.

6. A drive unit according to claim 1, wherein bearing supports (31, 59, 60, 62) for supporting the gear wheels of the gear stages are formed on the inner wall of the housing of the actuator.

7. A drive unit according to claim 6, wherein the bearing supports (31, 59, 60, 62) comprise pins (55a, 55b, 55c, 55d) on to which the gear wheels are placed.

8. A drive unit according to claim 1, wherein means of fastening, particularly pins (15) for positioning and fixing other functional units such as a circuit board (7) are integrally molded to the housing (11) of the actuator.

9. A drive unit according to claim 1, wherein a can (13) is integrally molded to an inner face of the housing (11) of the actuator, the can being designed to receive the electric motor, and wherein means of fastening are integrally molded to the can (13) that are designed to position and fix the electric motor accommodated in the can (13).

10. A drive unit according to claim 1, wherein the gear train is configured such that each gear stage realizes a transmission ratio of 2 to 8, or 4 to 5.

11. A drive unit according to claim 10, wherein the electric motor has a shaft (47) having a gear wheel (47′

) that meshes with a gear wheel (53;

79a) of the first gear stage.

12. An actuating drive for a flap actuator in a motor vehicle having a drive unit and a is brushless DC motor as the electric motor whose outside circumference is less than or equal to 60 mm, the drive unit comprising:

a gear train having at least a first gear stage and a last gear stage, wherein the gear train realizes a transmission ratio of greater than one from the electric motor to an output wheel (53′

″

, 81),

wherein each gear stage is formed by a gear drive and

wherein in the last gear stage one gear wheel (53″

) or alternatively two gear wheels (83, 83′

) connected in parallel are provided that each mesh with an upstream gear wheel (53′

, 79b) of the gear train and with the output wheel (53′

″

;

81), so as to transmit the torque acting on the last gear stage to this stage via the one gear wheel (53″

) or alternatively distributed over the two gear wheels (83, 83′

) connected in parallel,

wherein the drive unit (1) is accommodated in a housing (11) of the actuator that has at least a first and a second bearing support (59) for the gear wheels of the last gear stage, and to form this last gear stage, the two bearing supports (59) are fitted with the one gear wheel (53″

) or alternatively with the two gear wheels (83, 83′

) connected in parallel.

13. The actuating device according to claim 12, wherein the outside circumference is less than or equal to 30 mm.