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

• US 6,793,034 B2
• Filed: 01/18/2002
• Issued: 09/21/2004
• 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
• Primary Examiner(s): Ilan, Ruth
• Application Number:
  US09/683,556
• Publication Number:
  US 20030136597A1
• Time in Patent Office: 977 Days
• Field of Search: B60/G 2.1055, 180/285, 180/282, 180/279, 180/247, 180/242, 180/65.2, 180/277, 180/274, 701/22, 701/69, 701/45
• US Class Current: 180/285
• 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 said 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 (“

VSC”

) receiving input from an inertia switch and electric motor condition sensors, with said VSC activating said means to mechanically disconnect the output shaft from the drive wheels in the event that the inertia switch is activated, with said VSC further comprising a subsystem to monitor whether a means to reset an activated inertia switch has been activated and which accordingly deactivates said means to mechanically disconnect the output shaft from the drive wheels.

2. 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.

3. The system of claim 2 wherein the axle disconnect is electric powered.

4. The system of claim 2 wherein the axle disconnect is vacuum powered.

5. The system of claim 2 wherein the axle disconnect is a center disconnect.

6. The system of claim 2 wherein the axle disconnect is a wheel-end disconnect.

7. The system of claim 6 wherein the axle is limited slip axle.

8. A method for disconnecting at least one drive wheel from a vehicle with an electric motor connected to a powertrain, and having said 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;

determining whether the inertia switch has been activated; and

disconnecting the output shaft from at least one drive wheel in the event that the inertia switch has been activated.

9. The method of claim 8 wherein the step of disconnecting the output shaft from at least one drive wheel uses electric power.

10. The method of claim 8 wherein the step of disconnecting the output shaft from at least one drive wheel uses vacuum power.