High-pressure pump, in particular for a common-rail injection system

Abstract

A high-pressure pump having a plurality of individual feed pumps is described, the feed pumps being designed as modular pump units and being able to be lined up next to one another via their housings, which are provided with fluid-connecting channels. At least one line module being provided which can be coupled at least on one side to a housing of a modular pump unit and in which the fluid-connecting channels of the respectively adjacent housings form intake and discharge channels which, on the one hand, lead on further and/or, on the other hand, lead outward.

1 . A high-pressure pump, in particular for a common-rail injection system for internal combustion engines, having a plurality of feed pumps which each comprises at least one plunger guided in a bore leading into a feed space, and are driven via a common drive shaft having eccentric sections assigned to the respective plungers, and each feed space is connected via a pressure-controlled inlet valve to a low-pressure supply line and via a pressure-controlled outlet valve to a high-pressure output line, wherein the individual feed pumps are designed as modular pump units and can be lined up next to one another via their housings, which are provided with fluid-connecting channels, and wherein at least one line module is provided which can be coupled at least on one side to a housing of a modular unit and in which the fluid-connecting channels of the respectively adjacent housings form intake and discharge channels which, on the one hand, lead on further and/or, on the other hand, lead outward.  
     
     
         2 . The high-pressure pump as claimed in  claim 1 , wherein the plunger bore accommodating the plunger and the feed space are formed in a high-pressure part screwed to the housing.  
     
     
         3 . The high-pressure pump as claimed in  claim 1  or  2 , wherein each modular pump unit in each case comprises at least two plungers which lie diametrically opposite each other and are actuated by the same eccentric section together with an associated feed space and common housing.  
     
     
         4 . The high-pressure pump as claimed in  claim 1 , wherein each plunger is guided in the housing via a cup tappet and is prestressed against the associated eccentric section by means of a restoring spring.  
     
     
         5 . The high-pressure pump as claimed  claim 1 , wherein the drive shaft is mounted at least in the outer end walls of the housings which are placed on the end side of a row of modules.  
     
     
         6 . The high-pressure pump as claimed in  claim 5 , wherein, instead of the drive shaft being mounted at both ends in a respective housing end wall, it is mounted at one end in a line module forming one end of the housing and is mounted at the other end in a housing end wall.  
     
     
         7 . The high-pressure pump as claimed in  claim 1 , wherein a bearing socket for the drive shaft is formed in each case in line modules which are arranged between adjacent housings.  
     
     
         8 . The high-pressure pump as claimed in  claim 7 , wherein the diameter of the bearing socket is at least slightly larger than double the value of the largest radius of the eccentric sections of the drive shaft.  
     
     
         9 . The high-pressure pump as claimed in  claim 1 , wherein a forced-oil supply into the bearings of the drive shaft, of the rolling rings or sliding shoes and preferably into annular lubricating channels of the cup tappets is provided via an end piece fitted onto a housing end wall or line module provided on the end side.  
     
     
         10 . The high-pressure pump as claimed in  claim 9 , wherein the forced-oil supply to the bearings takes place via bores in the drive shaft and to the annular lubricating channels via channels in the housings and line modules.  
     
     
         11 . The high-pressure pump as claimed in  claim 1 , wherein the channels, which are provided in the housings of the pump units and in the line modules, are mutually orientated in the axial direction of the high-pressure pump and are sealed at the transition points, are provided for the low-pressure supply and for the high-pressure removal of diesel oil, for the removal of leakage of a mixture of diesel oil and lubricating oil, for the forced-oil supply and for the oil return line.  
     
     
         12 . The high-pressure pump as claimed in  claim 1 , having a plurality of plungers which are moved to and fro via a common drive shaft provided with eccentric sections, are guided in each case in a plunger bore leading into a feed space and are actuated by an eccentric section counter to the action of a restoring spring , wherein an annular collecting space for overflow lubricating oil and overflow diesel oil is formed on the feed-space side in the wall of the plunger bore and is connected via channels to a diesel-oil tank.  
     
     
         13 . The high-pressure pump as claimed in  claim 1 , having a plurality of plungers which are moved to an fro via a common drive shaft provided with eccentric sections, are guided in each case in a plunger bore leading into a feed space and are actuated by an eccentric section counter to the action of a storing spring in particular via a cup tappet which is guided in a bore in the housing, wherein, firstly, an eccentric space through which the drive shaft passes and, secondly, at least one annular lubricating channel which surrounds the respective plunger or cup tappet and is formed in the housing are connected to a lubricating-oil pressure supply, and wherein an annular spaceconnected to a lubricating-oil return flow is provided in the region of that section of the plunger or of the cup tappet which is on the feed-space side.  
     
     
         14 . The high-pressure pump as claimed in  claim 12  or  13 , wherein a pressure-maintaining valve is arranged in a channel section which is common to all of the channels conducting a mixture of lubricating- and diesel-oil leakages.  
     
     
         15 . The high-pressure pump as claimed in  claim 14 , wherein the pressure-maintaining valve can be set or controlled.  
     
     
         16 . The high-pressure pump as claimed in one  claim 1 , having a plurality of plungers which are moved to an fro via a common drive shaft provided with eccentric sections, are guided in each case through a plunger bore leading into a feed space and are actuated by an eccentric section counter to the action of a restoring spring with the interconnection of rolling elements, wherein sliding shoes which are of two-part design are provided as the rolling elements.  
     
     
         17 . The high-pressure pump as claimed in  claim 16 , wherein the sliding-shoe halves which can be screwed to each other have planar bearing surfaces on the plunger side for the respective plunger or for a cup tappet assigned to the plunger.  
     
     
         18 . The high-pressure pump as claimed in  claim 16  or  17 , wherein a sliding bearing or ball bearing is provided between the respective eccentric section and the associated sliding shoe.