Hydraulic power transmission and braking system for vehicles
AssigneeTex Trans Inc.
InventorBernhard Ulrich, Jr.
Life of this patent
Estimating the term…
Abstract
A hydraulic power transmission and braking system for vehicles in which individual hydraulic wheel motors are connected through suitable control apparatus to a variable displacement hydraulic pump which is driven by an appropriate power source. The displacement of the pump varies automatically in response to hydraulic fluid pressure and flow rate requirements imposed by the vehicle operating conditions. The power transmission control apparatus automatically switches from the 4-wheel drive mode to the 2-wheel drive mode as the vehicle accelerates past a predetermined speed. The braking control system proportions the braking force applied to each of the hydraulic wheel motors in accordance with the load imposed on that wheel by the vehicle operating conditions.
Claims16
A variable displacement hydraulic machine comprising:
- a cylindrical casing having a pair of parallel spaced end walls and a plurality of circumferentially spaced chambers, each chamber having a pair of hydraulic fluid ports in an end wall thereof;
- an orbiting member disposed within said cylindrical casing, said orbiting member having a pair of parallel spaced surfaces for intimately contacting said end walls of said cylindrical casing, and a plurality of legs extending radially into said circumferentially spaced chambers for covering and uncovering said hydraulic fluid ports during the orbiting motion of said orbiting member;
- a plurality of movable vanes connecting said orbiting member at points intermediate said legs to said cylindrical casing at points intermediate said chambers, said vanes intimately contacting said end walls of said cylindrical casing to provide fluid seals between adjacent chambers;
- an eccentric shaft having a first end and a second end, the first end of said eccentric shaft being rotatably mounted at a point on the axis of said cylindrical casing, said orbiting member being journaled on said eccentric shaft at a point intermediate its ends;
- and
- variable eccentric carrier means rotatably mounted on the axis of said cylindrical casing for rotatably engaging said second end of said eccentric shaft at a variable radius from the axis of said cylindrical casing so as to cause said second end of said eccentric shaft to follow an orbital path about the axis of said cylindrical casing whereby variation of the radius of said orbital path varies the radius of the orbital path of said orbiting member thus varying the displacement of said hydraulic machine.
A hydraulic machine comprising:
- a cylindrical casing having a plurality of circumferentially spaced chambers and a pair of parallel spaced end walls, said end walls having a pair of hydraulic fluid ports associated with each of said chambers;
- a shaft journaled centrally in said cylindrical casing;
- an orbiting member disposed within said cylindrical casing and journaled eccentrically on said shaft, said orbiting member having
- a pair of parallel spaced surfaces for intimately contacting said end walls of said cylindrical casing, and
- a plurality of legs, each of said legs extending into one of said circumferentially spaced chambers of said cylindrical casing for covering and uncovering said hydraulic fluid ports during orbital movement of said orbiting member;
- and a plurality of movable vanes connecting said orbiting member at points intermediate said legs to said cylindrical casing at points intermediate said chambers, said vanes intimately contacting said end walls of said cylindrical casing to provide fluid seals between adjacent chambers,
- each of said circumferentially spaced chambers being bounded by a portion of said cylindrical casing, a portion of said orbiting member, by one of said plurality of orbiting member legs, by at least two of said plurality of movable vanes in order that each of said chambers is essentially fluid tight,
- said cylindrical casing having a plurality of circumferentially spaced cavities, each of said cavities being positioned between each adjacent pair of said chambers, each of said plurality of vanes being movable within one of said cavities,
- means connecting each of said cavities to one of said chambers in order to reduce the pressure caused by the movement of said vanes within said cavities.
Dependencies are inferred from the claim text.