Pump unit

Abstract

A pump unit includes a housing which has an outwardly open recess, in which a pump is arranged. The recess is closed by a cover. The pump unit also has a pressure relief valve which is arranged in an opening of the housing which opens to the outside. The pressure relief valve has a valve seat which is formed in the opening and against which a seat valve member is loaded in the closing direction by way of a prestressed compression spring. The seat valve member can be loaded in the opening direction by the outlet pressure of the pump.

1 . A pump unit, comprising:
 a housing including an outwardly open recess, a pump arranged in the recess, and the recess closed by a cover; and   a pressure relief valve arranged in an opening of the housing, the pressure relief valve configured to open to an outside of the housing, the pressure relief valve including a valve seat formed in the opening, and the valve seat configured such that against the valve seat a seat valve member is loaded in a closing direction by way of a prestressed compression spring, the seat valve member configured to be loaded in an opening direction by an outlet pressure of the pump,   wherein the recess and the opening extend parallel to one another on a housing outer wall,   wherein the recess and the opening open to the outside out of the housing, and   wherein the recess and the opening are configured to be closed by the cover.   
     
     
         2 . The pump unit as claimed in  claim 1 , wherein the housing outer wall is planar in a region of orifices of the recess and the opening. 
     
     
         3 . The pump unit as claimed in  claim 2 , further comprising:
 a sealing groove configured to enclose the orifices of the recess and the opening jointly, the sealing groove formed in the housing outer wall; and   an elastic seal of corresponding shape inserted into the sealing groove,   wherein, in a closed position, the cover is in contact sealingly against the elastic seal.   
     
     
         4 . The pump unit as claimed in  claim 1 , wherein the cover is configured to be stressed into contact with the housing outer wall by way of screws configured to be screwed into threaded holes in the housing. 
     
     
         5 . The pump unit as claimed in  claim 1 , wherein the cover includes a guide attachment on a side which faces the housing, the guide attachment configured to correspond to a cross section of the orifice of the recess and to protrude into the recess. 
     
     
         6 . The pump unit as claimed in  claim 1 , wherein the compression spring which loads the seat valve member in the closing direction is supported on the cover. 
     
     
         7 . The pump unit as claimed in  claim 1 , wherein the seat valve member includes a coaxial guide shank on a side which faces away from the valve seat, the guide shank configured to be guided displaceably in a guide hole formed in the cover. 
     
     
         8 . The pump unit as claimed in  claim 7 , wherein the guide shank has at least one axial groove in a cylindrical circumferential face in a region which dips into the guide hole. 
     
     
         9 . The pump unit as claimed in  claim 6 , wherein the compression spring is a compression coil spring configured to enclose the guide shank at a radial spacing and is supported with a first end on the seat valve member and with a second end on the cover. 
     
     
         10 . The pump unit as claimed in  claim 1 , wherein the valve seat is a conical valve seat and the seat valve member is a conical seat valve member. 
     
     
         11 . The pump unit as claimed in  claim 1 , wherein an outlet side of the pressure relief valve is connected to an inlet of the pump via a channel formed in at least one of the housing and the cover. 
     
     
         12 . The pump unit as claimed in  claim 1 , wherein the pump is a charge pump, and an outlet of the charge pump is connected to an inlet of a main pump. 
     
     
         13 . The pump unit as claimed in  claim 12 , wherein the housing of the charge pump is configured to be flange-connected to the main pump.