EP0255681A2
Expired / Lapsed
EP
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Flow control system for a hydraulic pump
Assignee: SPX Technologies Inc
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Filing: 1987-07-27
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Granted: —
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Expires: 2007-07-27
Abstract
Abstract A hydraulic control system (10) having a supply of low pressure hydraulic fluid and a hydraulic pump (12) having a fluid inlet and a fluid outlet through which fluid is delivered at a high operating pressure when the pump (12) is pumping at its capacity. A valve (16) is placed in fluid communication with the supply of hydraulic fluid (14) and the pump fluid inlet for permitting fluid communication between the supply of hydraulic fluid (14) and the pump fluid inlet when in one mode of operation and for substantially preventing fluid communication between the supply of hydraulic fluid and the pump fluid when in a second mode of operation. A control means prevents the valve (16) from assuming its second mode of operation until the magnitude of the pressure at the pump fluid outlet is below a predetermined pressure. The predetermined pressure is set to be substantially below the pump operating pressure. The valve (16) mounted in the fluid inlet is adapted to rotate therein from a first position in which fluid is free to flow through the fluid inlet to a second position in which the valve (16) substantially prevents the flow of fluid through the inlet. Hydraulically controlled means are provided for rotating the valve (16) back and forth between the first and second positions.
Inventors
- 👤 Charles J. Bowden
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 17:35
CPC Classifications
F; F04; F04B; F04B49/00; F04B49/22; F04B49/225
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
149 words
An hydraulic control system including a supply of low pressure hydraulic fluid and an hydraulic pump having a fluid inlet and a fluid outlet through which fluid is delivered at a high operating pressure when said pump is pumping fluid at its capacity, characterized by a first valve in fluid communication with said supply of hydraulic fluid and said pump fluid inlet for permitting fluid communication between said supply of hydraulic fluid and said pump fluid inlet in a first mode of operation and for substantially preventing fluid communication between said supply of hydraulic fluid and said pump fluid inlet in a second mode of operation; and control means for preventing said first valve from assuming said second mode of operation until the magnitude of the pressure at said pump fluid outlet is below a first predetermined pressure, said first predetermined pressure being substantially below said pump operating pressure.
Claim 2
Dependent Claim
149 words
An hydraulic control system including a supply of low pressure hydraulic fluid and an hydraulic pump having a fluid inlet and a fluid outlet through which fluid is delivered at a high operating pressure when said pump is pumping fluid at its capacity, characterized by a first valve in fluid communication with said supply of hydraulic fluid and said pump fluid inlet for permitting fluid communication between said supply of hydraulic fluid and said pump fluid inlet in a first mode of operation and for substantially preventing fluid communication between said supply of hydraulic fluid and said pump fluid inlet in a second mode of operation; and control means for preventing said first valve from assuming said second mode of operation until the magnitude of the pressure at said pump fluid outlet is below a first predetermined pressure, said first predetermined pressure being substantially below said pump operating pressure.
Claim 3
Dependent Claim
84 words
An hydraulic control system according to claim 1, characterized in that said control means includes signal means in fluid communication with said fluid outlet for generating a control pressure signal, said first valve assuming said first mode of operation when the magnitude of said control pressure signal exceeds a second predetermined pressure and assuming said second mode of operation when the magnitude of said control pressure signal is below said second predetermined pressure, said second predetermined pressure being less then said first predetermined pressure.
Claim 4
Dependent Claim
70 words
An hydraulic control system according to claim 2, characterized in that a second valve is in fluid communication with said pump fluid outlet and said fluid supply and is responsive to the difference between the magnitude of the pressure of the fluid in said pump fluid outlet and the magnitude of said control pressure signal for diverting the flow of fluid from said pump fluid outlet to said fluid supply.
Claim 5
Dependent Claim
44 words
An hydraulic control system according to claim 3, characterized in that a third valve is provided for permitting a limited amount of flow from said pump fluid outlet to said supply of fluid when said first valve restricts flow to said pump fluid inlet.
Claim 6
Dependent Claim
61 words
An hydraulic control system according to claim 4, characterized in that the signal means includes a variable orifice in fluid communication with said pump fluid outlet and a fixed orifice in fluid communication with said variable orifice and said third valve, and in that said control pressure signal is generated at a point between said fixed orifice and said third valve.
Claim 7
Dependent Claim
98 words
An hydraulic control system including a housing having a fluid inlet and a fluid outlet contained therein, characterized by means contained within said housing for delivering hydraulic fluid received at said fluid inlet to said fluid outlet, a valve mounted in said fluid inlet and adapted to rotate therein from a first position in which fluid is free to flow through said fluid inlet to a second position in which said valve substantially prevents the flow of fluid through said inlet, and hydraulically controlled means for rotating said valve back and forth between said first and second positions.
Claim 8
Dependent Claim
98 words
An hydraulic control system including a housing having a fluid inlet and a fluid outlet contained therein, characterized by means contained within said housing for delivering hydraulic fluid received at said fluid inlet to said fluid outlet, a valve mounted in said fluid inlet and adapted to rotate therein from a first position in which fluid is free to flow through said fluid inlet to a second position in which said valve substantially prevents the flow of fluid through said inlet, and hydraulically controlled means for rotating said valve back and forth between said first and second positions.
Claim 9
Dependent Claim
55 words
An hydraulic control system according to claim 6, characterized in that the fluid inlet includes a portion having a circular cross-section and in that said valve is a butterfly valve having a disc shaped valve member adapted to substantially prevent the flow of fluid through said inlet when said valve is in its closed position.
Claim 10
Dependent Claim
35 words
An hydraulic control system according to claim 7, characterized in that the butterfly valve includes means for permitting a lubricating flow of hyraulic fluid through said pump when said valve is in the closed position.
Claim 11
Dependent Claim
92 words
An hydraulic control system according to claim 6, characterized in that the hydraulically controlled means includes signal means in fluid communication with said fluid outlet for generating a control pressure signal, a linear actuator adapted to reciprocate in a linear direction in response to the magnitude of said control signal, and motion translating means connected to said valve for converting the linear movement of said linear actuator to rotational movement to thereby cause said valve to rotate to its open and closed positions in response to the magnitude of said control signal.
Claim 12
Dependent Claim
151 words
An hydraulic control system according to claim 9, characterized in that the fluid inlet includes a portion having a circular cross-section, in that said valve is a butterfly valve having a disc shaped valve member adapted to substantially prevent the flow of fluid through said inlet when said valve is in its closed position, in that the valve includes a pivot rod extending diametrically across said portion of said fluid inlet and wherein said disc shaped valve member is affixed thereto, and in that the motion translating means includes a bore in one end of said linear actuator, said bore having at least one helical guide in the wall thereof and at least one projection on one end of said pivot rod, said projection adapted to ride in said helical guide as said linear actuator reciprocates to thereby impart rotational motion to said pivot rod to open and close said valve.
References Cited (Backward Citations)
No citation records indexed.
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