DE102008059636A1 - pump assembly - Google Patents

Abstract

A pump arrangement for conveying a fluid comprises at least a first (110) and a second pump unit (120), each comprising: a cylinder housing (111; 121) surrounding a fluid supply line (114; 124) for supplying the fluid and a fluid discharge ( 115, 125) for discharging the fluid. The at least one first (110) is identical in construction to the second (120) cylinder housing (111; 121) and the at least one first (110) and second fluid discharge (115; 125) are outside the at least one first and one second cylinder housing (111; 121) hydraulically coupled.

Description

The The invention relates to a pump arrangement for conveying a fluid.

Fuel injection systems of internal combustion engines have a near-engine high-pressure accumulator or a memory line, from or out of the individual fuel injection valves are fed. This high pressure accumulator is often referred to as common rail. The pump that supplies the high-pressure accumulator, should the necessary volume flow and the required fluid pressure precise and can provide efficiently. This pump may have a plurality of pistons having a common Supply high-pressure accumulator.

It it is an object of the invention to provide a pump assembly the cost-effective can be produced.

These Task is solved by a pump arrangement with the features of claim 1.

A Pump arrangement for delivery a fluid comprises at least a first and a second pump unit. The pump units each comprise a cylinder housing, the a fluid supply line for feeding surrounding the fluid. The cylinder housing further surrounds a fluid drainage for draining the fluid. The at least one first and the second cylinder housing are identical. The fluid discharges are outside of the at least one first and a second cylinder housing hydraulically coupled.

By a structurally identical design the cylinder housing and the hydraulic merging of the Fluid discharges outside the cylinder housing are less different components needed. As a result, a pump arrangement according to the invention cost-effective getting produced.

According to one another embodiment The pump assembly includes an element for merging the Fluid drains coupled to the first of the fluid drains can be. The pump assembly may further comprise a tubular element, coupled to the second of the fluid outlets and the merge element, so that the at least one first and second fluid drain hydraulic are coupled. So can the Fluid discharges particularly easy outside the at least one first and a second cylinder housing are hydraulically combined.

According to one another embodiment For example, the pump assembly includes a valve having a closure body. The valve is disposed on the first of the fluid outlets, so that a movement of the closing body in a direction is limited by the element for merging. Thereby, that the merge element as Stop for the valve is used, the construction of the pump assembly can continue be simplified.

The Merge element and the first of the cylinder housings can a common contact area have, so that the element for merging and the first of the cylinder housing hydraulically are tightly coupled. This makes the construction very easy will be realized.

The Merge element in one embodiment each round and / or oval cross sections of different diameters on. As a result, the assembly can be simplified.

The Merge element may be at least a first and a second supply line and at least have a derivative, so that the first of the leads with the derivation is aligned and the second of the leads transversely to the derivative is arranged.

In a further embodiment the pump arrangement comprises at least one means for mechanical Coupling of the element for merging with the first of the cylinder housing. That at least a means may comprise a spring ring which is in an annular groove on the outer surface of a Supply line of the element is held for merging. The spring ring can with an annular groove on an inner circumferential surface of the first of the fluid discharges corresponds. Such a locking connection by means of an elastic deformable spring ring is very simple and inexpensive in the production and leaves easy to assemble and disassemble if necessary.

The Pump arrangement comprises in a further embodiment, a coupling element for coupling the tubular element with the second of the fluid discharges. The pump assembly may include a further valve having a having another closing body and which is disposed on the second of the fluid discharges, so that a movement of the closing body in a direction is limited by the coupling element. As a result of that the coupling element as a stop for the other valve is used, the structure of the pump assembly can continue be simplified.

The Coupling element and the second of the cylinder housing may have a common contact surface, so that the coupling element for merging and the second of the cylinder housing hydraulically are tightly coupled.

Further Features, advantages and developments emerge from the following explained in conjunction with the figure Examples.

The FIG. 1 shows a schematic representation of a pump arrangement according to a Embodiment.

The figure shows a pump arrangement 100 , The pump arrangement 100 has a pump unit 110 and another pump unit 120 on. The pump units 110 and 120 are each with a crankshaft 101 coupled, so that the pump units by rotation of the crankshaft 101 can be driven.

The pump unit 110 has a cylinder housing 111 on, that's a cylinder room 112 surrounds. In the cylinder room 112 is a pump piston 113 arranged. The pump piston 113 is axially movable in the cylinder space. The cylinder housing 111 surrounds a fluid supply line 114 and a fluid drainage 115 , About the fluid supply line 114 can fluid in the cylinder chamber 112 be encouraged. Through the fluid drainage 115 can remove fluid from the cylinder space 112 be dissipated.

At the fluid outlet 115 is a valve 116 arranged. The valve 116 has a movable closing body 119 on. The closing body 119 is pressed by a spring against a part of the cylinder housing, so that the fluid drainage 115 closed to the outside. Exceeds the pressure with which the fluid in the fluid discharge 115 or in the cylinder chamber 112 is applied, the pressure that the Fe on the closing body 119 exercise, the valve opens 116 and releases a fluid flow.

The movement of the closing body 119 is moving away from the fluid drain 115 from an element 117 limited to merge. The element 117 for merging has a supply line 171 , another supply line 172 and a derivative 173 on. The derivative 173 is with the supply line 171 and the supply line 172 each hydraulically coupled. The derivative 173 Aligns with the supply line 171 , The supply line 172 is transverse to the supply line 171 arranged. The supply lines 171 . 172 and the derivative 173 can also be arranged at different angles to each other, so that the supply lines 171 . 172 with the derivative 173 can communicate hydraulically.

The element 117 for merging is with an area adjacent to the feed line 171 is with the pump unit 110 coupled. The element 117 to merge with the cylinder housing 111 coupled so that the supply line 117 hydraulically via the valve 116 with the fluid drainage 115 is coupled. Fluid from the fluid discharge 115 can over the supply line 171 for derivation 173 reach.

The element 117 to merge is by a means 118 for mechanical locking with the cylinder housing 111 coupled. The coupling can be further elements, for example, for centering the element 117 include. The means 118 for mechanical locking have a spring ring, which deform elastically and into an annular groove of the element 117 can be introduced. The spring washer fixes the element 117 at least partially in the cylinder housing 111 , In particular, the spring element engages 118 in a groove of the cylinder housing 111 one to the item 117 with the cylinder housing 111 to pair. The spring element 118 can also engage in an annular groove of the other elements, for example in an annular groove of the centering element.

The element 117 to merge is so with the cylinder housing 111 coupled to the cylinder housing 111 and the element 117 to merge a common contact surface 104 exhibit. The common contact area 104 is between the supply line 171 and the fluid discharge 115 arranged so that the cylinder housing 111 and the element 117 are tightly coupled together. Fluid coming from the fluid drainage 115 over the supply line 171 for derivation 173 can not get to the contact surface 104 penetrate to the outside.

The pump unit 120 has a cylinder housing 121 on, that's a cylinder room 122 surrounds. In the cylinder room 122 is a pump piston 123 arranged. The pump piston 123 is axially movable in the cylinder space. The cylinder housing 121 surrounds a fluid supply line 124 and a fluid drainage 125 , About the fluid supply line 124 can fluid in the cylinder chamber 122 be encouraged. Through the fluid drainage 125 can remove fluid from the cylinder space 122 be dissipated.

At the fluid outlet 125 is a valve 126 arranged. The valve 126 has a movable closing body 129 on. The closing body 129 is pressed by a spring against a part of the cylinder housing, so that the fluid drainage 125 closed to the outside. Exceeds the pressure with which the fluid in the fluid discharge 125 or in the cylinder chamber 122 is applied, the pressure that the spring on the closing body 129 exercise, the valve opens 126 and releases a fluid flow.

The movement of the closing body 129 is moving away from the fluid drain 125 from a connection element 127 limited. The connection element 127 surrounds a fluid line 130 , The fluid management 130 is with the fluid drainage 125 hydraulically coupled. The fluid line 130 Aligns with the fluid discharge 125 ,

The connection element 127 is with an area adjacent to the feed line 171 is with the pump unit 120 coupled. The connection element 127 is with the cylinder housing 121 coupled so that the supply line 127 hydraulically via the valve 126 with the fluid drainage 125 is coupled. Fluid from the fluid discharge 125 can be used to fluid line 130 reach.

The connection element 127 is by a means 128 for mechanical locking with the cylinder housing 121 coupled. The coupling can be further elements, for example, for centering the element 127 include. The means 128 for mechanical locking have a spring ring, which deform elastically and into an annular groove of the element 127 can be introduced. The spring washer fixes the element 127 at least partially in the cylinder housing 121 , In particular, the spring element engages 128 in a groove of the cylinder housing 121 one to the item 127 with the cylinder housing 121 to pair.

The fluid line 130 is with a pipe 102 hydraulically coupled. Fluid coming from the pump unit 120 is promoted, passes through the element 127 in the pipe 102 , The fluid passes through the pipe 102 in the supply line 172 and from there into the derivative 173 , In the element 117 becomes the fluid coming from the pump unit 110 is conveyed, and the fluid from the pump unit 120 funded is merged. The fluid coming from the pump unit 110 comes is via the supply line 171 for derivation 173 guided. The fluid coming from the pump unit 120 comes, gets over the pipe 102 and the line 172 for derivation 173 guided. About the derivation 173 can the fluid of the pump units 110 and 120 be conducted together. For example, the fluid from the drain 173 in a high pressure accumulator (not shown) of a common rail injection system out. By the element 117 will be operating both the fluid coming from the pump unit 110 is promoted, as well as the fluid from the other pump unit 120 is conveyed, led to a common high-pressure accumulator (not shown) of a common rail injection system.

This causes the fluid outside of the cylinder housing 111 . 121 in the element 117 can be merged, the cylinder housing 111 and 121 be executed identical. None of the housing requires integrated leads or leads for supplying, discharging or combining fluid from a plurality of pump units in the housing. As a result, pump assemblies can be formed with a plurality of pump units, wherein the respective pump units are of identical design, regardless of the number of pump units having the pump assembly. In particular, in each case the orientation of the fluid supply line 114 respectively 124 to the cylinder room 112 respectively 122 with both cylinder housings 111 respectively 121 equal. In particular, in each case the orientation of the fluid discharge 115 respectively 125 to the cylinder room 112 respectively 122 with both cylinder housings 111 respectively 121 equal. The fluid guide in the cylinder housing 111 corresponds to the fluid guide in the cylinder housing 121 , The structure of the cylinder housing 121 corresponds to the structure of the cylinder housing 111 , The cylinder housing of the pump assembly 110 are the same, regardless of the number of pump units of the pump assembly 110 ,

The element 117 to merge can also with the cylinder housing 121 the pump unit 120 be coupled. The connection element 127 is in then with the cylinder housing 111 the pump unit 110 , The pipe couples the element 117 for merging hydraulically with the connection element 127 , Fluid that from the pump unit 110 is promoted in operation, passes through the connection element 127 and the pipe to the element 117 to merge. The operation of the pump assembly as described above remains the same.

The pumped fluid of the pump units is combined outside the pump units in a separate element. A pump arrangement according to the invention can also have more than two pump units, for example three or more pump units. The element 117 for merging then has a corresponding number of leads 171 . 172 so that fluid from the plurality of pump units, for example the three or more pump units, into a drain 173 can be merged. For example, the item indicates 117 in one embodiment, three supply lines which are hydraulically coupled to a drain. One of the three supply lines is coupled to a pump unit such that the element for merging has a common contact surface with the pump housing of the pump unit. The other two supply lines are hydraulically coupled via pipe elements with one of the other two pump units.

In operation, by a rotational movement of the crankshaft 101 , which is rotatably mounted in a crank chamber, the pump piston 113 and the pump piston 123 moved radially to the drive shaft by the eccentric shape of the drive shaft. The crankcase is from a pump housing 103 surround. When moving in the direction of the drive shaft, the corresponding cylinder space 112 . 122 filled with fluid. The fluid is via the appropriate supply line 114 . 124 sucked into the cylinder space to be broken. By a further rotation of the crankshaft 101 the corresponding pump piston is moved axially away from the drive shaft and compresses the fluid located in the corresponding cylinder chamber. The compressed fluid may be following the compression stroke via the refractive fluid drain 115 . 125 be ejected. The fluid is then merged into a common fluid line and can be conveyed to a high-pressure fuel storage, the so-called common rail.

101

crankshaft

102

pipe

103

pump housing

104

contact area

105

contact area

110

pump unit

111

cylinder housing

112

cylinder space

113

pump pistons

114

fluid supply line

115

fluid discharge

116

Valve

117

element to merge

118

medium for mechanical locking

119

closing body

171

supply

172

supply

173

derivation

120

pump unit

121

cylinder housing

122

cylinder space

123

pump pistons

124

fluid supply line

125

fluid discharge

126

Valve

127

element

128

medium for mechanical locking

129

closing body

130

fluid line

Claims (11)

Pump arrangement for conveying a fluid, comprising: - at least one first ( 110 ) and a second pump unit ( 120 ), each comprising: - a cylinder housing ( 111 ; 121 ), the - a fluid supply line ( 114 ; 124 ) for supplying the fluid surrounds and - a fluid discharge ( 115 ; 125 ) for discharging the fluid, in which - the at least one first ( 110 ) and a second ( 120 ) Cylinder housing ( 111 ; 121 ) are identical and - the at least one first ( 110 ) and second fluid discharge ( 115 ; 125 ) outside the at least one first and a second cylinder housing ( 111 ; 121 ) are hydraulically coupled. Pump arrangement according to claim 1, comprising: - an element ( 117 ) for merging the fluid discharges with the first ( 115 ) of the fluid discharges is coupled, - a tubular element ( 102 ) that with the second ( 125 ) of the fluid discharges and the element ( 117 ) is coupled to merge, so that the at least one first ( 110 ) and second fluid discharge ( 115 ; 125 ) are hydraulically coupled. Pump arrangement according to claim 2, comprising: a valve ( 116 ), which has a closing body ( 119 ) and that at the first ( 115 ) of the fluid discharges is arranged, so that a movement of the closing body in a direction of the element ( 117 ) is limited to merge. Pump arrangement according to claim 2 or 3, in which the element ( 117 ) to merge and the first ( 111 ) the cylinder housing has a common contact surface ( 104 ), so that the element ( 117 ) to merge and the first ( 111 ) of the cylinder housing are hydraulically tightly coupled. Pump arrangement according to one of claims 2 to 4, wherein the element ( 117 ) for merging each round and / or oval cross-sections of different diameters. Pump arrangement according to one of claims 2 to 5, wherein the element ( 117 ) for merging at least a first ( 171 ) and a second ( 172 ) Supply line and at least one derivative ( 173 ), so that the first ( 171 ) of the supply lines with the derivative ( 173 ) is aligned and the second of the leads transverse to the derivative ( 173 ) is arranged. Pump arrangement according to one of claims 2 to 6, comprising: at least one means ( 128 ) for the mechanical coupling of the element ( 117 ) for merging with the first ( 111 ) the cylinder housing. Pump arrangement according to one of claims 2 to 7, wherein the at least one means ( 128 ) a spring washer ( 118 ), which in an annular groove on the outer circumferential surface of one of the supply lines ( 171 ) of the element ( 117 ) is held for merging. Pump assembly according to claim 8, wherein the spring washer ( 118 ) with an annular groove on an inner circumferential surface of the first ( 115 ) of the fluid discharges corresponds. Pump arrangement according to one of claims 1 to 9, comprising: - a coupling element ( 127 ) for coupling the tubular element ( 102 ) with the second ( 125 ) of the fluid discharges, - another valve ( 126 ), which has a further closing body ( 129 ) and that at the second ( 125 ) of the fluid discharges is arranged, so that a movement of the closing body in a direction of the coupling element ( 127 ) is limited. Pump arrangement according to one of claims 1 to 10, wherein the coupling element ( 127 ) and the second ( 121 ) the cylinder housing has a common contact surface ( 105 ), so that the coupling element ( 127 ) for merging and the second ( 121 ) of the cylinder housing are hydraulically tightly coupled.