US 6,305,762 B1 · Valve assembly for controlling actuation of an actuator of a track tensioning system

Abstract

A valve assembly for controlling actuation of an actuator of a track tensioning system for adjusting tension on a drive track chain includes a valve housing defining (i) a master chamber, (ii) a slave chamber, (iii) a fluid passage which fluidly couples the master chamber to the slave chamber, and (iv) a fluid outlet which fluidly couples the slave chamber to the actuator. The valve assembly also includes a master valve member positioned within the master chamber. The master valve member (i) isolates the master chamber from the slave chamber when the master valve member is positioned in a first master position, and (ii) places the master chamber in fluid communication with the slave chamber when the master valve member is positioned in a second master position. The valve assembly further includes a slave piston positioned within the slave chamber, the slave piston (i) isolates the fluid outlet from the slave chamber when the slave piston is positioned in a first slave position, and (ii) places the fluid outlet in fluid communication with the slave chamber when the slave piston is positioned in a second slave position. Movement of the master valve member from the first master position to the second master position causes movement of the slave piston from the first slave position to the second slave position. Movement of the slave piston from the first slave position to the second slave position causes actuation of the actuator, whereby tension on the drive track chain is adjusted by the actuator.

Claims18

Dependent claims

A valve assembly for controlling actuation of an actuator of a track tensioning system for adjusting tension on a drive track chain, comprising:

a valve housing defining (i) a master chamber, (ii) a slave chamber, (iii) a fluid passage which fluidly couples said master chamber to said slave chamber, and (iv) a fluid outlet which fluidly couples said slave chamber to said actuator;
a master valve member positioned within said master chamber, said master valve member (i) isolates said master chamber from said slave chamber when said master valve member is positioned in a first master position, and (ii) places said master chamber in fluid communication with said slave chamber when said master valve member is positioned in a second master position;
and
a slave piston positioned within said slave chamber, said slave piston (i) isolates said fluid outlet from said slave chamber when said slave piston is positioned in a first slave position, and (ii) places said fluid outlet in fluid communication with said slave chamber when said slave piston is positioned in a second slave position,
wherein movement of said master valve member from said first master position to said second master position causes movement of said slave piston from said first slave position to said second slave position, and
wherein movement of said slave piston from said first slave position to said second slave position causes actuation of said actuator, whereby tension on said drive track chain is adjusted by said actuator.

3 more elements

An undercarriage assembly of a work machine, comprising:

a pressurized hydraulic fluid source;
a drive track chain;
an actuator mechanically coupled to said drive track chain so as to adjust tension on said drive track chain;
and
a valve assembly for controlling actuation of said actuator, said valve assembly having:
(i) a valve housing defining (a) a fluid chamber, (b) a chamber inlet, and (c) a chamber outlet,
(ii) a piston positioned within said fluid chamber so as to divide said fluid chamber into a spring chamber portion and a high-pressure chamber portion, and
(iii) a biasing spring positioned in said spring chamber portion so as to exert a spring bias on an outer surface of said piston,
wherein (i) said chamber inlet fluidly couples said hydraulic fluid source to said spring chamber portion, (ii) said chamber outlet fluidly couples said high-pressure chamber portion to said actuator, (iii) said piston has a first fluid contact surface which is positioned in said spring chamber portion, (iv) said piston further has a second fluid contact surface which is positioned in said high-pressure chamber portion, (v) said first fluid contact surface has a first diameter, (vi) said second fluid contact surface has a second diameter, and (vii) said first diameter is greater than said second diameter.

6 more elements

An undercarriage assembly of a work machine, comprising:

a first frame member;
a second frame member which is movable relative to said first frame member;
an actuator mechanically coupled to said second frame member so as to move said second frame member relative to said first frame member;
an idler wheel rotatably secured to said second frame member;
a drive track chain which is advanced around said idler wheel;
a pressurized hydraulic fluid source;
and
a valve assembly for controlling actuation of said actuator, said valve assembly having:
(i) a valve housing defining (a) a fluid chamber, (b) a chamber inlet, and (c) a chamber outlet,
(ii) a piston positioned within said fluid chamber so as to divide said fluid chamber into a spring chamber portion and a high-pressure chamber portion, and
(iii) a biasing spring positioned in said spring chamber portion so as to exert a spring bias on an outer surface of said piston,
wherein (i) said chamber inlet fluidly couples said hydraulic fluid source to said spring chamber portion, (ii) said chamber outlet fluidly couples said high-pressure chamber portion to said actuator, (iii) said piston has a first fluid contact surface which is positioned in said spring chamber portion, (iv) said piston further has a second fluid contact surface which is positioned in said high-pressure chamber portion, (v) said first fluid contact surface has a first diameter, (vi) said second fluid contact surface has a second diameter, and (vii) said first diameter is greater than said second diameter.

9 more elements

Dependencies are inferred from the claim text.

Valve assembly for controlling actuation of an actuator of a track tensioning system

Life of this patent

Valve assembly for controlling actuation of an actuator of a track tensioning system

Life of this patent

Abstract

Claims18