Apparatus for cooling and lubricating an off-axis motor/generator in a transmission having two motor/generators

• US 7,944,106 B2
• Filed: 02/08/2010
• Issued: 05/17/2011
• Est. Priority Date: 11/17/2006
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Miller, Kent A., Sowul, Henryk
• Primary Examiner(s): Leung; Quyen
• Assistant Examiner(s): Desai; Naishadh N
• Application Number:
  US12/701,866
• Publication Number:
  US 20100132504A1
• Time in Patent Office: 463 Days
• Field of Search: 310/112, 310/114, 310/89, 310/90, 310/83, 310/75.R, 903/906, 903/951, 180/65.21, 180/65.22, 475 1- 10, 475/159, 475/160, 477 2- 29, 746/06.A
• US Class Current: 310/112
• CPC Class Codes: B60K 2001/003 with means for cooling the electrical propulsion units
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/405 Housings
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: F16H 57/0412 Cooling or heating; Control of temperature
• CPC Class Codes: F16H 57/0421 on or within the casing, e.g. shields or baffles for collecting lubricant, tubes, pipes, grooves, channels or the like
• CPC Class Codes: F16H 57/043 within rotary parts, e.g. axial channels or radial openings in shafts
• CPC Class Codes: F16H 57/0434 relating to lubrication supply, e.g. pumps arrangement of pumps F16H57/0441; Pressure control grooves with pumping effect for supplying lubricant F16H57/0428; generation and variation of line pressure for transmission control F16H61/0021
• CPC Class Codes: H02K 9/19 for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10T 74/2189 Cooling

Abstract

The present invention provides a hybrid transmission with two motor/generators, one being “on-axis” and sharing an axis of rotation with an input and output shaft of the transmission, and another being “off-axis” with a distinct axis of rotation from that of the first motor/generator. The transmission is adapted for cooling and lubricating the off-axis motor/generator, and includes a case at least partially defining a manifold. A transmission cover is mounted to the case such that the off-axis motor/generator is retained therebetween. The transmission cover at least partially defines an oil passage. The manifold is adapted to transfer oil onto a bearing device so that the bearing device is lubricated. Oil is also transferred through the oil passage and onto a torque transfer device such that the torque transfer device is lubricated.

Claims

1. A hybrid transmission comprising:

an input shaft and an output shaft which together define a first axis of rotation;

a transmission case at least partially defining a manifold;

a transmission cover mounted to the transmission case, the transmission cover at least partially defining an oil passage;

a first motor/generator at least partially enclosed by the transmission case, and having a first rotor sharing the first axis of rotation;

a second motor/generator at least partially enclosed by the transmission case, and having a second rotor with a second axis of rotation that is distinct from the first axis of rotation, wherein the second motor/generator is disposed between the transmission case and the transmission cover, the second motor/generator comprising;

a generally cylindrical stator disposed within a stator housing, the stator circumscribing the second rotor;

a tube disposed along the central axis of the second rotor;

a rotor drum mounted to the second rotor;

a rotor hub mounted to the rotor drum;

a first bearing configured to rotatably support the rotor drum, wherein oil is transferable through the manifold in order to lubricate the first bearing;

a second bearing configured to rotatably support the rotor hub, wherein oil is transferable through the manifold, and through the tube in order to lubricate the second bearing; and

a torque transfer device coupled to the rotor hub such that output from the second motor/generator can be transferred to the output shaft, wherein oil is transferable through the manifold, through the tube, and through the oil passage in order to lubricate the torque transfer device.

2. The hybrid transmission of claim 1, further comprising a coolant chamber defined between the transmission case and the stator housing of the second motor/generator, wherein oil is transferable into the coolant chamber to cool the second motor/generator.

3. The hybrid transmission of claim 1, wherein the rotor drum of the second motor/generator defines at least one exhaust hole and a drum cavity adapted to direct the oil toward the at least one exhaust hole, thereby limiting an accumulation of the oil within the rotor drum.

4. The hybrid transmission of claim 1, wherein the torque transfer device is a chain configured to transfer output from the second motor/generator to the output shaft.

5. The hybrid transmission of claim 1, wherein the torque transfer device is a transfer gear.

6. The hybrid transmission of claim 1, further comprising:

a pressure regulator valve;

a cooler feed limit valve;

a cooler in fluid communication with the manifold through the cooler feed limit valve; and

a pump adapted for providing oil to the chamber through the pressure regulator valve, and to the cooler through the cooler feed limit valve.

7. A hybrid transmission having an input shaft and an output shaft defining a first axis of rotation, the transmission comprising:

an on-axis motor/generator having a first rotor that shares the first axis of rotation with the input shaft and the output shaft;

an off-axis motor/generator unit having a second rotor that defines a second axis of rotation that is distinct from the first axis of rotation;

a case at least partially defining a manifold, wherein the second motor/generator is retained within and secured to the case,

a transmission cover mounted to the transmission case, such that the second motor/generator is retained between the transmission case and the transmission cover, the transmission cover at least partially defining an oil passage;

a torque transfer device;

a tube disposed along the central axis of the second rotor, and adapted for transferring oil through the oil passage and onto the torque transfer device; and

a bearing device;

wherein the manifold is adapted for transferring oil onto the bearing device such that the bearing device is lubricated, and wherein the oil passage is adapted to transfer oil onto the torque transfer device such that the torque transfer device is lubricated.

8. The hybrid transmission of claim 7, further comprising:

a pressure regulator valve;

a cooler feed limit valve;

a cooler in fluid communication with the manifold through the cooler feed limit valve; and

a pump adapted for providing oil to the chamber through the pressure regulator valve and to the cooler through the cooler feed limit valve.

9. The hybrid transmission of claim 7, wherein the first bearing device is adapted to rotatably support a rotor drum, and wherein the second bearing device is adapted to rotatably support a rotor hub.