Reciprocating piston pump

Claim 2

A reciprocating piston pump, especially for high pressures, comprising a pump housing hAving an aperture therein, said aperture having a radially larger part and a radially smaller part axially separated by a shoulder from each other, a valve housing inserted into said aperture and having a radially enlarged part and a radially smaller part axially extending from one end of said enlarged part and separated from it by a shoulder abutting against said shoulder on the wall of said aperture in said pump housing, a pump chamber defined by a wall portion of said smaller aperture part of said pump housing and by the end of said smaller part of said valve housing, a flow channel extending through said valve housing for passing a pressure medium therethrough, suction channel means adapted to communicate with said pump chamber, a suction valve in said pump chamber for controlling said suction channel means, a pressure valve on said valve housing for controlling said flow channel, closure wall means closing said aperture in said pump housing at the side thereof opposite to the side of said valve housing facing said pump chamber, a pressure-valve chamber between said valve housing and said closure wall means and located behind said pressure valve, as seen in the direction of flow of said pressure medium from said pump chamber, and a compensating chamber separate from said pressure-valve chamber and communicating with said flow channel between said pump chamber and said pressure-valve chamber, said compensating chamber having a wall forming the other end of said enlarged part of said valve housing so that the pressure medium contained in said compensating chamber will act upon said other end of said enlarged part in the same direction as the pressure medium contained in said pressure-valve chamber acts upon said valve housing so as to press said valve housing in the direction toward said pump chamber and thereby to press said shoulder of said valve housing against said shoulder on the wall of said aperture in said pump housing, the surface area of said valve housing acted upon in said direction by said pressure medium in said pressure-valve chamber and in said compensating chamber being larger than the surface area of said valve housing acted upon by said pressure medium in the opposite direction.

Claim 3

A reciprocating piston pump as defined in claim 1, in which said surface area of said valve housing acted upon by the pressure medium in said compensating chamber in said direction toward said pump chamber has such a size that the difference between the surface areas of said valve housing acted upon by the pressure medium in said opposite direction in said pump chamber and in said first direction in said compensating chamber is at least substantially equal to the surface area of said valve housing acted upon by said pressure medium in said first direction in said pressure-valve chamber.

Claim 4

A reciprocating piston pump as defined in claim 1, in which said valve housing has a second radially smaller part axially extending from the other end of said radially larger part, said compensating chamber forming an annular chamber surrounding the part of said second smaller part adjacent to said other end of said larger part.

Claim 5

A reciprocating piston pump as defined in claim 3, in which said flow channel extends substantially axially through said valve housing, said valve housing having channel means extending substantially transverse to said flow channel and connecting the same to said compensating chamber.

Claim 6

A reciprocating piston pump as defined in claim 1, in which said suction channel means are provided in said valve housing and consist of longitudinal channels and transverse channels each having one end terminating into the associated channel, and further suction channel means in said pump housing, the other ends of said transverse channels being open at the outer periphery of said enlarged part of said valve housing and communicating with said further suction channel means, and the other ends of said longitudinal channels adapted to be opened and closed by said suction valve.

Claim 7

A reciprocating piston pump as defined in claim 5, in which said flow channel extends substantially axially through said valve housing, and said suction channel means in said valve housing extend radially outside of and around said flow channel, said suction valve forming an annular valve.

Claim 8

A reciprocating piston pump as defined in claim 6, in which said suction valve and said pressure valve are provided at the opposite ends of said valve housing, a valve shaft secured to a first of said valves and extending through said valve housing and also through and projecting from the other valve, a spring bearing mounted on the projecting end of said valve shaft, and a common valve spring having one end acting upon said other valve and another end acting upon said spring bearing, said valve spring tending to close both of said valves on said valve housing.

Claim 9

A reciprocating piston pump as defined in claim 7, in which said pressure valve is secured to one end of said valve shaft.

Claim 10

A reciprocating piston pump as defined in claim 7, in which said other valve is slidable along and guided by said valve shaft of said first valve.

Claim 11

A reciprocating piston pump as defined in claim 1, in which said closure wall means forms an insert inserted into said aperture and secured to said pump chamber and having an inner end surface forming a second wall opposite to and axially spaced from said first wall of said compensating chamber and defining the latter between said two walls, said insert containing said pressure-valve chamber having an outer diameter smaller than that of said compensating chamber.

Claim 12

A reciprocating piston pump as defined in claim 10, in which said valve housing has a second radially smaller part axially extending from the other end of said enlarged part and having a smaller diameter than said first part, said insert being cup-shaped, the rim part of said cup forming said second wall of said compensating chamber, the inner wall surface of the recess of said cup containing the free end of said second smaller part and further defining the side wall of said pressure-valve chamber which is further defined by the bottom of said cup and the free end wall of said second smaller part of said valve member, said free end wall into which said flow channel terminates forming a valve seat, said pressure valve projecting into said pressure-valve chamber and adapted to open and close said valve seat, and transverse outlet channel means extending from said pressure-valve chamber through the side wall of said cup and communicating with further outlet channel means in said pump housing.

Claim 13

A reciprocating piston pump as defined in claim 11, in which said insert has an outer diameter equal to the diameter of said radially larger part of said aperture in said pump housing.

Claim 14

A reciprocating piston pump, especially for high pressures, comprising a pump housing having an aperture therein, said aperture having a radially larger part and a radially smaller part axially separated by a shoulder from each other, a valve housing inserted into said aperture and having a radially enlarged part and a radially smaller part axially extending from one end of said enlarged part and separated from it by a shoulder abutting against said shoulder on the wall of said aperture in said pump housing, a pump chamber defined by a wall portion of said smaller aperture part of said pump housing and by the end of said smaller part of said valve housing, flow channel means extending from said chamber, suction channel means adapted to communicate with said pump chamber, a suction valve in said pump chamber for controlling said suction channel means, a pressure valve for controlling said flow channel means, closure wall means closing said aperture in said pump housing at the side thereof opposite to the side of said valve housing facing said pump chamber, a pressure-valve chamber between said valve housing and said closure wall means and located behind said pressure valve, as seen in the dIrection of flow of said pressure medium from said pump chamber, and a compensating chamber separate from said pressure-valve chamber and communicating with said flow channel means between said pump chamber and said pressure-valve chamber, said compensating chamber having a wall forming the other end of said enlarged part of said valve housing so that the pressure medium contained in said compensating chamber will act upon said other end of said enlarged part in the same direction as the pressure medium contained in said pressure-valve chamber acts upon said valve housing so as to press said valve housing in the direction toward said pump chamber and thereby to press said shoulder of said valve housing against said shoulder on the wall of said aperture in said pump housing, the surface area of said valve housing acted upon by the pressure medium in said compensating chamber in said direction toward said pump chamber has such a size that the difference between the surface areas of said valve housing acted upon by the pressure medium in said opposite direction in said pump chamber and in said first direction in said compensating chamber is substantially equal to the surface area of said valve housing acted upon by said pressure medium in said first direction in said pressure-valve chamber.

Claim 15

A reciprocating piston pump, especially for high pressures, comprising a pump housing having an aperture therein, said aperture having a radially larger part and a radially smaller part axially separated by a shoulder from each other, a valve housing inserted into said aperture and having a radially enlarged part and a radially smaller part axially extending from one end of said enlarged part and separated from it by a shoulder abutting against said shoulder on the wall of said aperture in said pump housing, a pump chamber defined by a wall portion of said smaller aperture part of said pump housing and by the end of said smaller part of said valve housing, flow channel means extending from said chamber, suction channel means adapted to communicate with said pump chamber, a suction valve in said pump chamber for controlling said suction channel means, a pressure valve for controlling said flow channel means, closure wall means closing said aperture in said pump housing at the side thereof opposite to the side of said valve housing facing said pump chamber, a pressure-valve chamber between said valve housing and said closure wall means and located behind said pressure valve, as seen in the dIrection of flow of said pressure medium from said pump chamber, and a compensating chamber separate from said pressure-valve chamber and communicating with said flow channel means between said pump chamber and said pressure-valve chamber, said compensating chamber having a wall forming the other end of said enlarged part of said valve housing so that the pressure medium contained in said compensating chamber will act upon said other end of said enlarged part in the same direction as the pressure medium contained in said pressure-valve chamber acts upon said valve housing so as to press said valve housing in the direction toward said pump chamber and thereby to press said shoulder of said valve housing against said shoulder on the wall of said aperture in said pump housing, the surface area of said valve housing acted upon by the pressure medium in said compensating chamber in said direction toward said pump chamber has such a size that the difference between the surface areas of said valve housing acted upon by the pressure medium in said opposite direction in said pump chamber and in said first direction in said compensating chamber is substantially equal to the surface area of said valve housing acted upon by said pressure medium in said first direction in said pressure-valve chamber.

Claim 16

A reciprocation piston pump as defined in claim 13, in which said flow channel means extends substantially axialy through said valve housing, said valve housing having channel means extending substantially transverse to said flow channel and connecting the same to said compensating chamber.