Oil exchange in hydraulically operated and electro-hydraulically operated hydraulic valves

Patent metadata

Field	Value
Publication number	US-10100849-B2
Application number	US-201515320536-A
Country	US
Kind code	B2
Filing date	Jun 23, 2015
Priority date	Jun 23, 2014
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A hydraulic valve includes a valve body having first and second ends, a bore extending therebetween, and first and second drain passages opening to the bore; a spool disposed in the bore and biased in a neutral position, the spool having first and second ends and first and second annuli axially spaced from the first and second ends respectively, whereby when the spool is in the neutral position, the first and second drain passages are connected to first and second bores respectively via the respective annulus, and wherein the spool is axially movable relative to the body by fluid acting on one of the ends to block fluid flow from the first and second bores to the first and second drain passages.

First claim

What is claimed is:

1. A hydraulic valve including:
a valve body having a first end and a second end, a bore extending therebetween, a first drain passage formed as an annular groove on an interior surface of the valve body, and a second drain passage formed as a respective annular groove on the interior surface of the valve body;
a first end cap coupled to the first end of the valve body and defining with the first end of the valve body a first end bore;
a second end cap coupled to the second end of the valve body and defining with the second end of the valve body a second end bore; and
a spool disposed in the bore and biased in a neutral position, the spool separating the first end bore from the second end bore, wherein the spool has a first end and a second end, and wherein the spool includes (i) a first annular groove formed on an exterior surface of the spool such that the first annular groove is axially spaced from the first end of the spool, and (ii) a second annular groove formed on the exterior surface of the spool such that the second annular groove is axially spaced from the second end of the spool,
wherein when the spool is in the neutral position, the first annular groove forms a first axially extending flow passage that fluidly connects the first end bore to the first drain passage, and the second annular groove forms a second axially extending flow passage that fluidly connects the second end bore to the second drain passage,
wherein the spool is axially movable relative to the valve body by fluid acting on the first end of the spool or the second end of the spool, and wherein when the spool is axially shifted by a predetermined distance, the spool blocks fluid flow from the first end bore to the first drain passage or from the second end bore to the second drain passage.

2. The hydraulic valve according to claim 1 , wherein each of the first annular groove and the second annular groove has a first end and a second end closer to the respective end of the spool than the first end.

3. The hydraulic valve according to claim 2 , wherein the second end of the first annular groove or the second annular groove is configured to seal against the bore when the spool has been moved axially to block fluid flow through the first annular groove or the second annular groove.

4. The hydraulic valve according to claim 1 , wherein the spool blocks fluid flow from the first end bore to the first drain passage or from the second end bore to the second drain passage by axially moving the first annular groove or the second annular groove out of fluidic communication with a respective end bore and/or a respective drain passage.

5. The hydraulic valve according to claim 1 , further including one or more resilient members disposed in each end bore biasing the spool in the neutral position.

6. A hydraulic valve including:
a valve body having a first end and a second end, a bore extending therebetween, and at least one drain passage formed as an annular groove on an interior surface of the valve body;
a spool disposed in the bore, the spool having a first end and a second end and at least one annular groove proximate, and terminating before, the first end or the second end of the spool, wherein when the spool is in a neutral position, the at least one annular groove forms an axially extending flow passage that fluidly connects the at least one drain passage to an end bore disposed at the first end or the second end of the spool, and wherein the spool is axially movable relative to the valve body by fluid acting on the first end of the spool or the second end of the spool, and wherein when the spool is axially shifted by a predetermined distance, the spool blocks fluid flow from the end bore to the at least one drain passage by axially moving the at least one annular groove out of fluidic communication with the end bore and/or the at least one drain passage; and
one or more resilient members disposed in the end bore biasing the spool in the neutral position.

7. The hydraulic valve according to claim 1 , wherein when the spool is in the neutral position: (i) the first axially extending flow passage has a first end that partially overlaps with the first drain passage and a second end that is configured to be exposed to fluid disposed in the first end bore such that the first axially extending flow passage fluidly connects the first end bore to the first drain passage, and (ii) the second axially extending flow passage has a respective first end that partially overlaps with the second drain passage and a respective second end that is configured to be exposed to fluid disposed in the second end bore such that the second axially extending flow passage fluidly connects the second end bore to the second drain passage.

8. The hydraulic valve according to claim 7 , wherein when the spool is axially shifted by the predetermined distance, the second end of the first axially extending flow passage or the respective second end of the second axially extending flow passage is precluded via the interior surface of the valve body from being exposed to the first end bore or the second end bore, thereby blocking fluid flow from the first end bore to the first drain passage or from the second end bore to the second drain passage.

9. The hydraulic valve according to claim 1 , wherein when the spool is in the neutral position: (i) a fluid path is formed from the first end bore to the exterior surface of the spool, through the first axially extending flow passage to the first drain passage, and (ii) a second flow path is formed from the second end bore to the exterior surface of the spool, through the second axially extending flow passage to the second drain passage.

10. The hydraulic valve according to claim 6 , wherein the at least one annular groove has a first end and a second end that is closer to a respective end of the spool than the first end of the at least one annular groove, and wherein the second end of the at least one annular groove is configured to seal against the bore when the spool has been moved axially the predetermined distance, thereby blocking fluid flow through the at least one annular groove.

11. A hydraulic valve including:
a valve body having a first end and a second end, a bore extending therebetween, a first drain passage formed as an annular groove on an interior surface of the valve body, and a second drain passage formed as a respective annular groove on the interior surface of the valve body;
a spool disposed in the bore and having a first end and a second end, wherein the spool includes (i) a first annular groove formed on an exterior surface of the spool such that the first annular groove is axially spaced from the first end of the spool, and (ii) a second annular groove formed on the exterior surface of the spool such that the second annular groove is axially spaced from the second end of the spool;
a first end cap coupled to the first end of the valve body and defining with the first end of the valve body a first end bore;
a second end cap coupled to the second end of the valve body and defining with the second end of the valve body a second end bore; and
one or more resilient members disposed in each end bore biasing the spool in a neutral position at which the first annular groove forms a first axially extending flow passage that fluidly connects the first end bore to the first drain passage, and the second annular groove forms a second axially extending flow passage that fluidly connects the second end bore to the second drain passage,
wherein the spool is axially movable relative to the valve body by fluid acting on the first end of the spool or the second end of the spool, and wherein when the

Assignees

• Parker Hannifin Corp

Inventors

• Reynolds Dennis L
• Slattery Brian

Classifications

• F15B21/045

  Compensating for variations in viscosity or temperature · CPC title

• F15B13/042

  operated by fluid pressure {(F15B13/0401, F15B13/0416 take precedence)} · CPC title

• Y10T137/86582

  Pilot-actuated · CPC title

• F16K11/07

  with cylindrical slides · CPC title

• F15B13/043

  with electrically-controlled pilot valves · CPC title