FULLY AUTOMATIC LOCKING INTERAXLE DIFFERENTIAL FOR TANDEM VEHICLES

• US 3,706,350 A
• Filed: 12/09/1970
• Issued: 12/19/1972
• Est. Priority Date: 12/09/1970
• Status: Expired due to Term

• Current Assignee: Ronald D. Bokovoy
• Original Assignee: Ronald D. Bokovoy
• Inventors: Bokovoy, Ronald D.
• Primary Examiner(s): Hoffman, Drayton E.
• Assistant Examiner(s): Abraham, George F.
• Application Number:
  US05/096,569
• Time in Patent Office: 741 Days
• Field of Search: 180/24.09,23
• US Class Current: 180/24.09
• CPC Class Codes: B60K 17/36 for driving tandem wheels

Abstract

An interaxle differential mechanism adapted to deliver torque from a driving shaft to the rear axles and the rear-rear axles of a tandem drive vehicle wherein provision is made for distributing the torque to the rear-rear axles and the rear axles without incurring individual rear-rear axle spin-out or forward-rear axle spin-out, and wherein provision is made also for automatically disconnecting from the driveline either the rear axles or the rear-rear axles when a tendency exists for one or both rear axles or one or both rear-rear axles to overrun due to turning maneuvers.

Claims

1. A tandem axle driveline for road vehicles comprising, a pair of rear-rear axles, a pair of rear axles, a drive shaft connecting said axles, a first differential assembly connecting one end of said drive shaft to each of said rear-rear axles including differential gearing having an input member connected to said drive shaft and two output members connected respectively to said rear-rear axle shafts, a second differential assembly having a power input element and two power output elements connected respectively to each of said rear axle shafts, an interaxle differential assembly having a power input member, a common housing for said interaxle differential assembly and said second differential assembly having separate portions enclosing each, drive gearing adjacent said interaxle differential assembly in the housing portion for the latter, said interaxle differential assembly having a pair of output elements, one of said interaxle differential output elements being connected drivably through said drive gearing to the power input element of said second differential assembly, the other interaxle differential output element being concentric with said power input member of said interaxle differential assembly and connected to the other end of said drive shaft, a first clutch member connected drivably to the power input element for said interaxle differential, a pair of output clutch elements with registering clutch teeth connected respectively to the torque output elements of said interaxle differential assembly, and cam means for selectively disengaging each of said pair of clutch elements from said input clutch member comprising registering cam parts carried by each of said clutch elements and by said input clutch member whereby the clutch teeth of one clutch element and said input clutch member are moved out of engagement when a tendency exists for an associated axle shaft to overrun.

2. A tandem axle driveline for road vehicles comprising, a pair of rear-rear axles, a pair of rear axles, a drive shaft connecting said axles, a first differential assembly connecting one end of said drive shaft to each of said rear-rear axles including differential gearing having an input member connected to said drive shaft and two output members connected respectively to said rear-rear axle shafts, a second differential assembly having a power inpuT element and two power output elements connected respectively to each of said rear axle shafts, an inter-axle differential assembly having a power input member, a common housing for said interaxle differential assembly and said second differential assembly having separate portions enclosing each, drive gearing adjacent said interaxle differential assembly in the housing portion for the latter, said interaxle differential assembly having a pair of output elements, one of said interaxle differential output elements being connected drivably through said drive gearing to the power input element of said second differential assembly, the other interaxle differential output element being concentric with said power input member of said interaxle differential assembly and connected to the other end of said drive shaft, a first clutch member connected drivably to the power input element for said interaxle differential, a pair of output clutch elements connected respectively to the torque output elements of said interaxle differential assembly, and means for selectively disengaging each of said pair of clutch elements from said input clutch member comprising registering parts carried by each of said clutch elements and by said input clutch member whereby an output clutch element and said input clutch member are moved out of engagement when a tendency exists for an associated axle shaft to overrun.

3. The combination set forth in claim 1 wherein each differential assembly comprises a power input pinion, a ring gear, a pair of side gears, one side gear being connected to one of the associated axle shafts and the other side gear being connected to the other of the associated axle shafts, a carrier connected to said ring gear, and planet pinions carried by said carrier in meshing engagement with each of said side gears.

4. The combination set forth in claim 1 wherein the other output element of said interaxle differential assembly comprises a cross shaft disposed transversely with respect to the axis of said rear axles and having one end thereof connected drivably to said other end of said drive shaft whereby the torque delivered to said interaxle differential is divided between the rear-rear axles and the rear axles when the motions of the rear-rear axles and the rear axles are in synchronism.

5. The combination as set forth in claim 1, wherein the other output element of said interaxle differential assembly comprises a cross shaft journaled in said common housing in a direction parallel to the axis of rotation of the power input member of said interaxle differential assembly, said cross shaft being connected through said drive shaft to power input portions of said first differential assembly.

6. The combination as set forth in claim 3, wherein the other output element of said interaxle differential assembly comprises a cross shaft journaled in said common housing in a direction parallel to the axis of rotation of the power input member of said interaxle differential assembly, said cross shaft being connected through said drive shaft to power input portions of said first differential assembly.

7. The combination as set forth in claim 4, wherein said cross shaft is journaled in said common housing in a direction parallel to the axis of rotation of the power input member of said interaxle differential assembly, said cross shaft being connected through said drive shaft to power input portions of said first differential assembly.

8. A tandem axle driveline for use in a wheeled vehicle having an engine, rear-rear traction wheels, a first differential assembly having torque output elements connected to a separate one of said rear-rear traction wheels, a second differential assembly having an input element and two output elements connected to separate ones of said rear axles, an interaxle differential having two output elements and an input element, the input element of said interaxle differential being adapted to be connected to said engine, a geared connection between one output eLement of said interaxle differential and the input element of said second differential assembly, the input element of said first differential assembly being connected to the other output element of said interaxle differential, disengageable clutch means for drivably connecting the input element of said interaxle differential with each of the output elements thereof, cam means including registering parts connected to said input element of said interaxle differential and each of the output elements thereof for disconnecting the clutch means associated with said one and said other output elements of said interaxle differential when one associated differential output element tends to overrun with respect to another, said second differential assembly and said interaxle differential having a common differential housing, the geared connection between said one output element of said interaxle differential and the input element of said second differential assembly being situated within said common housing, and a cross shaft journaled in said common housing in a direction parallel to the axis of rotation of the power input member of said interaxle differential, and said cross shaft being connected to the other output element of said interaxle differential and to power input portions of said first differential assembly.