Differential lock with non-rotating hydraulically actuated piston

• US 4,867,010 A
• Filed: 07/28/1988
• Issued: 09/19/1989
• Est. Priority Date: 07/28/1988
• Status: Expired due to Fees

• Current Assignee: Deere & Company Moline IL A Corporation of
• Original Assignee: Deere & Company
• Inventors: Stettler, Werner Jr.
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US07/225,426
• Time in Patent Office: 418 Days
• Field of Search: 74/711, 74/710.5
• US Class Current: 475/86
• CPC Class Codes: F16H 2048/204 Control of arrangements for suppressing differential actions
• CPC Class Codes: F16H 2200/2071 using three freewheel mechanism
• CPC Class Codes: F16H 48/08 comprising bevel gears
• CPC Class Codes: F16H 48/22 using friction clutches or brakes
• CPC Class Codes: F16H 48/30 using externally-actuatable means
• CPC Class Codes: F16H 48/32 using fluid pressure actuators
• CPC Class Codes: F16H 48/34 using electromagnetic or electric actuators
• CPC Class Codes: F16H 48/40 characterised by features of the rotating cases

Abstract

A differential lock is activated by a non-rotating piston mounted substantially inside the side quill of the differential. Non-rotating seals are provided between the side quill and the piston to form a pressure chamber for the piston. A thrust bearing is provided between the piston and the pressure plate of the clutch of the differential lock to transmit force from the piston to the clutch while allowing relative rotation therebetween.

Claims

1. A lockable differential comprising:

first and second non-rotatable side quills;

a differential housing rotatably mounted about said side quills;

first and second driven shafts extending into said housing through said first and second side quills, respectively;

first and second side gears fixed for rotation with said first and second shafts, respectively;

a plurality of pinion gears rotatably mounted in said differential housing and engaging said side gears;

clutch means for selectively fixing at least said first side gear for rotation with said housing; and

actuating means for selectively actuating said clutch means, said actuating means being positioned substantially within and non-rotating relative to said first side quill, said actuating means comprising;

a thrust bearing for applying pressure directly to said clutch;

a hydraulic piston for applying pressure directly to said thrust bearing.

2. The differential of claim 1, further characterized in that the bearing means is selected from the group consisting of needle bearings and thrust washers.

3. The differential of claim 1, further characterized in that a hydraulic chamber for driving the piston is formed between the piston and the side quill.

4. The differential of claim 3, further characterized in that seals extend between surfaces of the piston and the side quill, said hydraulic chamber being defined between said piston, side quill and seals.

5. The differential of claim 3, further characterized in that return spring means are provided for biasing the actuating means away from the clutch.

6. The lockable differential of claim 1, wherein said actuating means further comprises non-rotating seals extending between said piston and said first side quill to define a hydraulic chamber therebetween.

7. The lockable differential of claim 1, wherein said thrust bearing is selected from the group consisting of needle bearings and thrust washers.

8. A lockable differential comprising:

first and second non-rotatable side quills;

a differential housing rotatably mounted about said side quills;

first and second driven shafts extending into said housing through said first and second side quills, respectively;

first and second side gears fixed for rotation with said first and second shafts, respectively;

a plurality of pinion gears rotatably mounted in said differential housing and engaging said side gears;

clutch means for selectively fixing at least said first side gear for rotation with said housing; and

actuating means for selectively actuating said clutch means, said actuating means being positioned substantially within and non-rotating relative to said first side quill, and comprising;

a hydraulic piston;

non-rotating seals extending between said piston and said first side quill to define a hydraulic chamber therebetween;

an extension of said piston extending beyond said hydraulic chamber in a direction away from said clutch means;

a lock ring on said extension; and

a spring compressed between said lock ring and said first side quill to bias said hydraulic piston away from said clutch means.

9. A lockable differential comprising:

first and second non-rotatable side quills;

a differential housing rotatably mounted about said side quills;

first and second driven shafts extending into said housing through said first and second side quills, respectively;

first and second side gears fixed for rotation with said first and second shafts, respectively;

a plurality of pinion gears rotatably mounted in said differential housing and engaging said side gears;

clutch means for selectively fixing at least said first side gear for rotation with said housing; and

actuating means for selectively actuating said clutch means, said actuating means being positioned substantially within and non-rotating relative to said first side quill;

a cross shaft extending between said first and second side gears;

means for preventing axial and rotary motion of said cross-shaft relative to the other one of said side gears; and

means for preventing axial motion and allowing rotary motion of said cross-shaft relative to the other one of said side gears.