IP Library Granted Patent US 7,628,240
Granted Patent B2
US 7,628,240 · App. 11/277,054 · Granted Dec 8, 2009

Fluid transmission with improved traction control

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Quick Facts
Patent No.
US 7,628,240
App. No.
11/277,054
Granted
Dec 8, 2009
Kind
B2
Abstract

An electronic traction control system for a vehicle having multiple hydraulic driven wheels includes a plurality of digital displacement pumps, a plurality of drive systems having counterbalance valves and motors used to drive wheels, and electronic flow control valves used in association with each drive assembly. Additionally the system has a steering mechanism that is electrically connected to a digital sensor and a proportional sensor that sends signals to a system controller that operates the functioning of the digital displacement hydraulic pumps.

Claims (11)

1. A hydraulic transmission comprising:

a steering mechanism;

a system controller fluidly connected to the steering mechanism;

a plurality of digital displacement hydrostatic pumps operably connected to the system controller;

a plurality of drive assemblies fluidly connected to the plurality of the digital displacement pumps that receive fluid from the plurality of digital displacement pumps to rotate a plurality of wheels

wherein each digital displacement pump is fluidly connected to a separate drive assembly;

a sensor electrically connected to the system controller that sends a sequence of pulses to a commutating valve within one of the plurality of digital displacement hydrostatic pumps such that a sequence of flow pulses is produced, a time average of which corresponds to a correct hydraulic flow to one of the plurality of drive assemblies to rotate a wheel based upon the sensor and operator inputs.

2. The device of claim 1 wherein the digital displacement pump is within an open circuit having a fluid reservoir.

3. The device of claim 1 further comprising bi-directional valve fluidly connected to the digital displacement pump.

4. The device of claim 1 wherein the drive system comprises at least one counterbalance valve fluidly connected to a motor such that the motor generates driving and braking torque to control rotation of the wheel.

5. The device of claim 1 wherein the sensor is a digital sensor.

Assignments (2)
CHANGE OF NAME Recorded Apr 9, 2014
From: SAUER-DANFOSS INC.
To: DANFOSS POWER SOLUTIONS INC.
Reel/Frame 032641/0351 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 21, 2006
From: CALDWELL, NIALL J.
To: SAUER-DANFOSS INC.
Reel/Frame 017337/0850 →