Power transfer unit (ptu) assembly with hydraulically actuated disconnect rear output shaft

Patent metadata

Field	Value
Publication number	US-2016288642-A1
Application number	US-201615084959-A
Country	US
Kind code	A1
Filing date	Mar 30, 2016
Priority date	Apr 2, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

An arrangement of a vehicle is provided having normal transverse engine/transmission normal two-wheel drive operation which can be selectively placed into four-wheel drive operation wherein a pump which powers the coupling or uncoupling is independent of the transmission lubrication pump and is powered by the transmission.

First claim

What is claimed is:

1 . An arrangement for an automotive passenger vehicle having normal front-wheel drive and selective four-wheel drive, said arrangement comprising:
a transmission transversely mounted in said vehicle powered by a transversely-mounted vehicle engine, said transmission having a lubrication pump; a front axle differential powered by said transmission having a casing extending transversely to said vehicle main axis, said front axle differential having front wheel shafts connecting with side gears for powering front wheel of said vehicle; a rear axle input shaft connected with front axle differential casing and encircling at least one of said front wheel shafts; a rear axle input gear rotatably mounted on said rear axle input shaft for powering a torsionally connected prop shaft; a rear axle differential torsionally connected with said prop shaft; a shift collar having a first position torsionally coupling said rear axle input shaft with said rear axle input gear and a second position decoupling said rear axle input gear with said rear axle input shaft; a hydraulic actuator for translating said shift collar; and a hydraulic pump independent of said transmission lubrication pump, said hydraulic pump being powered by said transmission, said hydraulic pump powering said hydraulic actuator.

2 . An arrangement as described in claim 1 wherein said actuator includes a cylinder with a piston pressurizable on both sides of said piston and said actuator is provided within a frame rotatively mounting at least an end of said rear axle input shaft.

3 . An arrangement as described in claim 2 wherein each side of said piston has individual solenoid actuated control to deliver fluid to said side of said piston or to release said side of said piston to a sump.

4 . An arrangement as described in claim 1 wherein said rear axle differential has a ring gear torsionally connected with the prop shaft and said ring gear is connected with a casing having a clutch connection with one of said rear wheels.

5 . An arrangement as described in claim 1 wherein said actuator includes a piston mounted inside a frame rotatively mounting at least an end of said rear axle input shaft and wherein said piston is fabricated from aluminum and said shift collar is fabricated from steel.

6 . An arrangement as described in claim 1 having an actuator with a piston inside a frame rotatively mounting at least one end of said rear axle input shaft wherein said piston can be assembled within the frame from one side of the frame.

7 . An arrangement as described in claim 1 wherein said actuator includes a piston having a leg aligned by a groove provided in a frame rotatively mounting at least an end of said rear axle input shaft.

8 . An arrangement as described in claim 2 wherein said actuator has an applied pressure chamber and a release pressure chamber sealed at a common radius.

9 . An arrangement as described in claim 1 wherein said hydraulic pump is torsionally connected to said one of said wheel shafts that is encircled by said rear axle input shaft by a gear train.

10 . An arrangement as described in claim 1 wherein said hydraulic pump is connected with an accumulator.

11 . An arrangement as described in claim 10 wherein said hydraulic pump is connected with said accumulator via a check valve.

12 . An arrangement as described in claim 11 wherein the pressure within said accumulator pilots operation of said hydraulic pump.

13 . An arrangement as described in claim 10 wherein said hydraulic pump in a steady state does not have enough capacity to operate said hydraulic actuator and wherein said accumulator has enough capacity for operating said hydraulic actuator multiple times.

14 . An arrangement for an automotive passenger vehicle having a normal front-wheel drive and selective four-wheel drive, said arrangement comprising:
a transmission transversely mounted in said vehicle powered by a transversely-mounted vehicle engine, said transmission having a lubrication pump; a front axle differential powered by said transmission having a casing extending transversely to said vehicle main axis, said front axle differential having front wheel shafts connecting with side gears for powering front wheels of said vehicle; a rear axle input shaft connected with said front axle differential casing and encircling at least one of said front wheel shafts; a rear axle input gear rotatably mounted on said rear axle input shaft for powering a torsionally connected prop shaft; a rear axle differential with a ring gear torsionally connected with said prop shaft, said ring gear being connected with a casing having drive gears powering side gears connected with said rear wheel shafts, said rear wheel shafts powering rear wheels of said vehicle, said casing also having a clutch connection with one of said rear wheels, said rear axle differential having a first state of operation differentially powering said rear wheels and said rear axle differential having a second state wherein said casing has a disconnected clutch connection with one of said rear wheels to allow said rear wheels to be non-driven and freewheel with respect to one another; a shift collar mounted within a frame rotatively mounting an end of said rear axle input shaft for selectively coupling said rear axle input gear with said rear axle input shaft; said shift collar having a first position torsionally coupling said rear axle input gear with said rear axle input shaft, and said shift collar having a second position uncoupling said rear axle input shaft gear from said rear axle input shaft; a hydraulic actuator for translating said shift collar including a piston mounted within said frame, said piston having a seal separating an applied pressure chamber and a release pressure chamber, said piston being fabricated from aluminum having a bumper connection with said shift collar and said shift collar being fabricated from steel; a hydraulic pump torsionally gear connected with a gear connected on said wheel shaft that is encircled by said rear axle input shaft; and an accumulator fluidly connected with said pump and said hydraulic actuator to supply pressurized hydraulic fluid to said actuator.

15 . An arrangement for an automotive passenger vehicle having a normal front-wheel drive and selective four-wheel drive, said arrangement comprising:
a transmission transversely mounted in said vehicle powered by a transversely-mounted vehicle engine, said transmission having a lubrication pump; a front axle differential powered by said transmission having a casing extending transversely to said vehicle main axis, said front axle differential having front wheel shafts connecting with side gears for powering front wheels of said vehicle; a rear axle input shaft connected with said front axle differential casing and encircling at least one of said front wheel shafts; a rear axle input gear rotatably mounted on said rear axle input shaft for powering a torsionally connected prop shaft; a rear axle differential with a ring gear torsionally connected with said prop shaft, said ring gear being connected with a casing having drive gears powering side gears connected with said rear wheel shafts, said rear wheel shafts powering rear wheels of said vehicle, said casing also having a clutch connection with one of said rear wheels, said rear axle differential having a first state of operation differentially powering said rear wheels and said rear axle differential having a second state wherein said casing has a disconnected clutch connection with one of said rear wheels to a

Assignees

• Borgwarner Inc

Inventors

• Rode John H
• Cradit Jeremy L
• Feldt Keith V

Classifications

• B60K2023/0866

  with hydraulic means only · CPC title

• B60K23/0808

  for varying torque distribution between driven axles, e.g. by transfer clutch · CPC title

• B60K17/3515

  with a clutch adjacent to traction wheel, e.g. automatic wheel hub · CPC title

• B60K17/35

  including arrangements for suppressing or influencing the power transfer, e.g. viscous clutches · CPC title

• B60K17/344 Primary

  having a transfer gear · CPC title