HYDRAULIC PUMP AND VALVE UNIT

• US 3,824,043 A
• Filed: 06/07/1973
• Issued: 07/16/1974
• Est. Priority Date: 06/06/1973
• Status: Expired due to Term

• Current Assignee: Randy J. Nordell
• Original Assignee: Randy J. Nordell
• Inventors: Nordell, Randy J.
• Primary Examiner(s): Freeh, William I.
• Assistant Examiner(s): Ward, Arnold F.
• Application Number:
  US05/367,713
• Time in Patent Office: 404 Days
• Field of Search: 137/625.23,625.43 417/441,437,485,568,440 60/477,462,481,461 254/93H,89H
• US Class Current: 417/440
• CPC Class Codes: B66F 3/42 with self-contained pumps, e.g. actuated by hand
• CPC Class Codes: F04B 53/10 Valves; Arrangement of valves
• CPC Class Codes: F04B 53/102 Disc valves
• CPC Class Codes: F04B 53/109 inlet and outlet valve forming one unit
• CPC Class Codes: F04B 7/00 Piston machines or pumps characterised by having positively-driven valving

Abstract

A hydraulic pump and valve unit for operating a hydraulically powered device, such as a hydraulic power cylinder for raising and lowering the cab of an automotive truck, includes a pump portion closely coupled to a valve portion, the latter having a cylindrical valve spool with an axial bore adapted to receive hydraulic fluid from the pump portion of the unit. The valve spool is rotatably mounted and arranged so as to supply inflowing hydraulic fluid under pressure to one port of the hydraulically powered device and to receive return fluid from another port of such device when in one position, and to reverse said supply and return in a rotated position. The pump is located between a hydraulic fluid reservoir and the valve, and the supply of hydraulic fluid from the former to the latter by the pump is through check-valved passage means providing a substantially direct and free flow path for the fluid.

Claims

1. A hydraulic pump and valve unit, comprising a pump portion and a valve portion closely coupled in fluid flow communication with each other through a flow passage extending therebetween, the pump portion being a reservoir for hydraulic fluid and the valve portion comprising a valve body and a valve spool rotatably mounted in the valve body and having an axial bore therein in direct fluid flow communication with said flow passage, said flow passage extending from said reservoir to said axial bore;

a pump cylinder and piston in said pump portion of the unit, the cylinder having a port opening into said flow passage between the reservoir and the valve for intake and discharge of hydraulic fluid on the suction and pressure strokes, respectively, of said piston;

check valve means between said port and said reservoir for permitting fluid to flow from the reservoir to the pump cylinder on the suction stroke of the piston but preventing backflow into said reservoir on the pressure stroke of the piston;

check valve means between said port and said valve for permitting fluid to flow from the pump cylinder into the valve on the pressure stroke of the piston by way of said flow passage and said axial bore but preventing backflow into said cylinder on the suction stroke of the piston;

sets of cooperative flow passages in said valve spool and said valve body for selective register by rotation of the valve spool to control outflow and return flow of hydraulic fluid from and to the unit;

return flow passage means extending from the valve body through the pump portion into communication with said reservoir;

means for operating the pump piston; and

means for rotating the valve spool.

2. A hydraulic pump and valve unit as defined in claim 1, wherein the second-named check valve means is located within the axial bore of the valve spool.

3. A hydraulic pump and valve unit as defined in claim 1, wherein flow passage means lead from the flow passage between pump portion and valve portion of the unit to the reservoir;

and wherein a pressure relief valve is positioned to control flow through said flow passage means.

4. A hydraulic pump and valve unit as defined in claim 1, wherein the sets of cooperative flow passages comprise a pair of divergent flow passages extending radially through the valve spool at a location in common along the length thereof and in communication with the axial bore thereof and opening into the exterior circumferential surface of the valve spool;

a pair of flow passages extending transversely through the valve body in circumferential alignment with said divergent flow passages;

a circumferential groove formed in the said exterior surface of the valve spool spaced longitudinally thereof from said dIvergent flow passages;

a longitudinal groove formed in the said exterior circumferential surface of the valve spool and extending from communication with said circumferential groove to a location on said exterior circumferential surface of the valve spool that lies between the port openings thereinto of said divergent flow passages; and

a flow passage in the valve body in registry with said circumferential groove and in flow communication with the return flow passage means.

5. A hydraulic pump and valve unit as defined in claim 4, wherein the port openings of the divergent flow passages are separated by 120* and the portion of the longitudinal groove that lies therebetween is separated from each of said port openings by 120*.

6. A hydraulic pump and valve unit as defined in claim 4, wherein a flow restriction is placed with respect to the return flow passage means and valve body flow passage in registry therewith so as to restrict return flow therethrough.

7. A hydraulic pump and valve unit as defined by claim 1, wherein the axial bore of the valve spool and the flow passage extending between pump portion and valve portion are rectilinearly aligned.