Electronically actuated locking differential

• US 6,551,209 B2
• Filed: 06/08/2001
• Issued: 04/22/2003
• Est. Priority Date: 01/18/2000
• Status: Expired due to Term

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Eaton Corp. (Wisconsin) (Eaton Corporation PLC.)
• Inventors: Ludwig, Allan S., Rosiek, Joseph F., Cheadle, Ross K., McAuliffe, Lawrence Jr.
• Primary Examiner(s): Rodriguez, Saul
• Assistant Examiner(s): Parekh, Ankur
• Application Number:
  US09/877,830
• Publication Number:
  US 20010044355A1
• Time in Patent Office: 683 Days
• Field of Search: 475/150, 475/231, 475/239, 192/35, 192/84.92, 192/84.7
• US Class Current: 475/150
• CPC Class Codes: F16H 2048/204 Control of arrangements for suppressing differential actions
• CPC Class Codes: F16H 2048/346 using a linear motor
• CPC Class Codes: F16H 48/22 using friction clutches or brakes
• CPC Class Codes: F16H 48/24 using positive clutches or brakes
• CPC Class Codes: F16H 48/295 using multiple means for force boosting
• CPC Class Codes: F16H 48/30 using externally-actuatable means
• CPC Class Codes: F16H 48/34 using electromagnetic or electric actuators

Abstract

A differential gear mechanism including a first output gear (25), and a cam and ramp actuator (55) including first (59) and second (63) actuating plates, relative rotation of which results in axial movement of said first plate (59) toward said first output gear (25). The mechanism includes an electromagnetic actuator (57) operable to cause rotation of the second actuating plate (63), relative to a gear case (11). Both actuating plates (59,63) are disposed external to an end wall (53) of the gear case, the first actuating plate (59) having a plurality of actuation members (85) extending axially through openings (81) in the end wall. A locking plate (41) is disposed adjacent the first output gear (25), and is fixed to be non-rotatable relative to the gear case, but axially moveable therein. The output gear (25) defines an array of teeth (39) and the locking plate (41) defines a plurality of recesses (43), adapted to receive the teeth, and lock the locking plate (41) relative to the output gear whenever the cam and ramp actuator (55) and the actuation members (85) move the locking plate to a locked position (FIG. 4).

Claims

1. A differential gear mechanism including a gear case defining an axis of rotation and a gear chamber;

differential gearing disposed in said gear chamber including at least one input gear and first and second output gears;

means operable to limit rotation of said first output gear relative to said gear case for common rotation therewith;

actuation means for said rotation limiting means, said actuation means including first and second actuating plates comprising a cam and ramp actuator, wherein relative rotation of said first and second actuating plates from an unactuated condition to an actuated condition is effective to move said rotation limiting means toward an engaged condition;

said second actuating plate being disposed, in said unactuated condition, to rotate with said gear case;

an electromagnetic actuator disposed adjacent said second actuating plate and operable, in response to an electrical input signal, to cause rotation of said second actuating plate relative to said gear case;

characterized by;

(a) said first and second actuating plates being disposed external to a gear case end wall, and said first actuating plate being axially moveable toward said end wall and having associated therewith a plurality of actuation members extending axially through corresponding openings in said end wall;

(b) said rotation limiting means comprising a locking portion fixed for rotation with said first output gear;

(c) said locking portion and said plurality of actuation members cooperating to provide means for locking said first output gear to a non-rotatable locked position relative to said gear case when said first actuating plate moves toward said end wall, moving said actuation members toward a locked position relative to said first output gear; and

(d) said electromagnetic actuator comprising a stationary, generally annular electromagnetic coil disposed in a generally surrounding relationship to said second actuating plate, and said electromagnetic actuator including a member fixed to rotate with said second actuating plate.

2. A differential gear mechanism as claimed in claim 1, characterized by means biasing said first actuating plate from said locked position away from said gear case end wall when said first and second actuating plates are in said unactuated condition.

3. A differential gear mechanism as claimed in claim 1, characterized by said locking portion being generally annular about said axis of rotation, and said plurality of actuation members being disposed in a generally annular array about said axis of rotation and axially adjacent with said locking portion.

4. A differential gear mechanism as claimed in claim 1, characterized by said actuation means further comprising a plurality of cam members in operable engagement with said first and second actuating plates.