Hybrid electric vehicle auxiliary oil pump

• US 6,805,647 B2
• Filed: 09/27/2002
• Issued: 10/19/2004
• Est. Priority Date: 09/27/2002
• Status: Active Grant

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Ortmann, Walter Joseph, Silveri, Andrew John, Kraska, Marvin Paul
• Primary Examiner(s): HO, HA DINH
• Application Number:
  US10/065,242
• Publication Number:
  US 20040063533A1
• Time in Patent Office: 753 Days
• Field of Search: 477/3, 477/7, 475/4, 475/122, 475/123
• US Class Current: 475/4
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60K 6/547 the transmission being a stepped gearing
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• 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: F16H 61/0031 using auxiliary pumps, e.g. pump driven by a different power source than the engine
• CPC Class Codes: F16H 61/0206 Layout of electro-hydraulic control circuits, e.g. arrangement of valves for control of actuators selecting and moving final output members, e.g. shift forks F16H61/2807
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/919 Stepped shift
• CPC Class Codes: Y10S 903/945 Characterized by control of gearing, e.g. control of transmission ratio

Abstract

An automatic transmission for a hybrid electric vehicle where an engine is shut down during vehicle stops to improve fuel economy. The automatic transmission includes a main pump that is driven off of a transmission input shaft, and an electronically driven auxiliary pump. A shut down shuttle valve switches a hydraulic circuit connection from the main pump to the auxiliary pump for a low-reverse clutch and a forward clutch when the vehicle stops in drive or low gear. A pressure transducer, controller and steady state relay allow for closed loop feedback to control the auxiliary pump in order to assure sufficient hydraulic pressure while minimizing power consumption.

Claims

1. A transmission for a hybrid electric vehicle comprising:

an input shaft with a main transmission fluid pump drivingly connected thereto;

an electronically controlled hydraulic shift system;

a low-reverse clutch and a forward clutch connected to the hydraulic shift system;

an electronically driven fluid pump having a fluid output; and

a pressure transducer operatively engaging the fluid output;

a controller in communication with the pressure transducer, and a solid state relay electronically connected to and drivable by the controller, and with the electronically driven pump electronically connected to and drivable by the solid state relay;

a shut down shuttle valve operatively engaging the electrically driven fluid pump, the low/reverse clutch and the forward clutch and switchable to selectively engage and disengage the electronically driven pump from the hydraulic shift system.

2. The transmission of claim 1 further including a forward-reverse solenoid and a forward-reverse shuttle, and the shut down shuttle has a first position where the forward-reverse solenoid and forward reverse shuttle are exposed to fluid pressure from the main transmission fluid pump and a second position where the forward-reverse solenoid and forward-reverse shuttle are exposed to fluid pressure from the electronically driven fluid pump.

3. The transmission of claim 2 wherein the shut down shuttle is shiftable from the first position to the second position when the fluid pressure produced by the electronically driven fluid pump exceeds the fluid pressure produced by the main transmission fluid pump.

4. The transmission of claim 3 wherein the shut down shuttle is shiftable from the second position to the first position when the fluid pressure produced by the electronically driven fluid pump is less than the fluid pressure produced by the main transmission fluid pump.

5. The transmission of claim 2 wherein the shut down shuttle is shiftable from the second position to the first position when the fluid pressure produced by the electronically driven fluid pump is less than the fluid pressure produced by the main transmission fluid pump.

6. The transmission of claim 1 further including a second pressure transducer operatively engaging the forward clutch.

7. A hybrid powertrain for a vehicle comprising:

an internal combustion engine;

a traction motor drivingly connected to the engine; and

a transmission having an input shaft, with a main transmission fluid pump drivingly connected thereto, an electronically controlled hydraulic shift system, a low-reverse clutch and a forward clutch connected to the hydraulic shift system, an electronically driven fluid pump having a fluid output, a pressure transducer operatively engaging the fluid output, a controller in communication with the pressure transducer, a solid state relay electronically connected to and drivable by the controller, with the electronically driven pump electronically connected to and drivable by the solid state relay, and with a shut down shuttle valve operatively engaging the electrically driven fluid pump, the low/reverse clutch and the forward clutch and switchable to selectively engage and disengage the electronically driven pump from the hydraulic shift system.

8. The hybrid powertrain of claim 7 further including a forward-reverse solenoid and a forward-reverse shuttle, and the shut down shuttle has a first position where the forward-reverse solenoid and forward reverse shuttle are exposed to fluid pressure from the main transmission fluid pump and a second position where the forward-reverse solenoid and forward-reverse shuttle are exposed to fluid pressure from the electronically driven fluid pump.

9. The hybrid powertrain of claim 8 wherein the shut down shuttle is shiftable from the first position to the second position when the fluid pressure produced by the electronically driven fluid pump exceeds the fluid pressure produced by the main transmission fluid pump.