Wheel-end and center axle disconnects for an electric or HEV

• US 20030136597A1
• Filed: 01/18/2002
• Published: 07/24/2003
• Est. Priority Date: 01/18/2002
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Tyson, Curtis Lee, Woestman, Joanne Theresa, OʼRear, John, Raftari, Abbas, Garg, Vijay K.
• Granted Patent: US 6,793,034 B2
• Time in Patent Office: Days
• US Class Current: 180/242
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/914 Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/916 with plurality of drive axles

Abstract

This invention is a method and system to disconnect drive wheels from the powertrain of any electric powered vehicle. A vehicle controller monitors input from, for example, an inertia switch and electric motor generator conditions and can disconnect the output shaft from the drive wheels in predetermined vehicle conditions such as during a rear-end collision, or abnormal electric motor conditions such as over-torque, over-temperature, or over-current. The invention can be configured to monitor and respond to driver demand for four-wheel drive, two-wheel drive, and neutral tow. The disconnect device can comprise a disconnect actuator and joint attached to an axle disconnect. The axle disconnect can be electric or vacuum powered and positioned as a center disconnect or a wheel-end disconnect. The invention can be configured for conventional or limited slip axles.

Claims

1. A system to disconnect at least one drive wheel from a vehicle with an electric motor connected to a powertrain, comprising:

the powertrain having an electric motor mechanically connected to an output shaft, the output shaft mechanically connected to at least one axle, the axle mechanically connected to at least one drive wheel;

the axle further comprising a means to mechanically disconnect the output shaft from at least one drive wheel;

a vehicle system controller comprising input from an inertia switch and electric motor conditions and can activate the means to mechanically disconnect the output shaft from the drive wheels in predetermined vehicle conditions.

2. The system of claim 1 wherein the predetermined vehicle conditions comprise activation of the inertia switch.

3. The system of claim 1 wherein the predetermined vehicle conditions comprise abnormal electric motor conditions.

4. The system of claim 1 wherein the VSC further comprises monitors for driver demand for four wheel drive, two wheel drive, and neutral tow and activates the means to mechanically disconnect the output shaft from at least one drive wheel to meet that demand.

5. The system of claim 1 wherein the VSC further comprises input to monitor whether a means to reset an activated inertia switch has been activated and accordingly deactivates the means to mechanically disconnect the output shaft from the drive wheels.

6. The system of claim 3 wherein the electric motor conditions comprise motor over-current, motor over-torque, and motor over-temperature.

7. The system of claim 1 wherein the means to mechanically disconnect the output shaft from the drive wheels comprises a disconnect actuator and joint attached to an axle disconnect.

8. The system of claim 7 wherein the axle disconnect is electric powered.

9. The system of claim 7 wherein the axle disconnect is vacuum powered.

10. The system of claim 7 wherein the axle disconnect is a center disconnect.

11. The system of claim 7 wherein the axle disconnect is a wheel-end disconnect.

12. The system of claim 10 wherein the axle is a conventional axle.

13. The system of claim 11 wherein the axle is a limited slip axle.

14. A method for disconnecting at least one drive wheel from a vehicle with an electric motor connected to a powertrain having an electric motor mechanically connected to an output shaft, the output shaft mechanically connected to at least one axle, the axle mechanically connected to at least one drive wheel, the steps comprising:

monitoring input from an inertia switch and electric motor conditions;

predetermining vehicle conditions to disconnect the output shaft from the drive wheels; and

disconnecting the output shaft from at least one drive wheel when the predetermined vehicle conditions occur.

15. The method of claim 14 wherein the step of predetermining vehicle conditions to disconnect the output shaft from the drive wheels comprises the step of determining that the inertia switch has been activated.

16. The method of claim 14 wherein the step of predetermining vehicle conditions to disconnect the output shaft from the drive wheels comprises the step of determining abnormal electric motor conditions exist.

17. The method of claim 14 wherein the step of disconnecting the output shaft from at least one drive wheel uses electric power.

18. The method of claim 14 wherein the step of disconnecting the output shaft from at least one drive wheel uses vacuum power.