DE102018210503A1 - pump assembly - Google Patents

Abstract

The invention relates to a pump arrangement (11) with at least one main feed pump (18) for fuel, which comprises a pump piston (5) which can be moved back and forth by means of a plunger device (9) which is located in an annular space (10) radially outside the pump piston (5) can be moved back and forth in translation, is driven by a camshaft (16), which is arranged rotatably about an axis of rotation in an engine compartment (17) of a pump housing body (2), and with an auxiliary feed pump (19), the tappet device ( 9) is used as a displacer of the auxiliary feed pump (19) and the annular space (10) radially outside the pump piston (5) as an auxiliary pump chamber (20). In order to reduce the design effort when providing fuel with the pump arrangement (11), the Auxiliary feed pump (19) designed as a lubricant pump.

Description

The invention relates to a pump arrangement with at least one main feed pump for fuel, which comprises a pump piston which can be moved back and forth and which is driven by a camshaft via a tappet device which can be moved back and forth translationally in an annular space radially outside the pump piston an axis of rotation is rotatably arranged in an engine space of a pump housing body, and with an auxiliary feed pump, the tappet device being used as a displacer of the auxiliary feed pump and the annular space radially outside the pump piston as an auxiliary pump chamber.

State of the art

From the European patent application EP 1 184 568 B1 A fuel pump is known, comprising a plurality of radially spaced pump arrangements, each of which has a pump piston, which can be moved back and forth within a piston bore formed in a pump housing under the influence of a corresponding driven driver element, this driver element having the function of one To transmit force to the pump piston while it is performing a forward stroke, the piston bore defining a pump chamber within which compression of fuel occurs to a relatively high value due to the reverse movement of the pump piston within the pump bore, one end region of the driver element with another Bore is provided, wherein a surface connected to the end region of the driver element partially delimits an annular auxiliary pump chamber for fuel, the further bore delimiting a working chamber which is arranged to receive fuel, wherein a force can be generated on the driver element that acts in the reverse direction to increase the volume of the pump chamber during a backward stroke of the pump piston, wherein the fuel pump further comprises a first supply path that connects between the auxiliary pump chamber, a first pump arrangement and the pump chamber represents at least one of the other pump arrangements, such that fuel displaced from the auxiliary pump chamber can be released during operation through the first supply path to the at least one of the other pump chambers, the auxiliary pump chambers and the first supply path being designed and designed to ensure that Fuel can flow through the second fuel supply path at a given rotational speed of the pump at a substantially constant flow rate.

Disclosure of the invention

The object of the invention is to reduce the design effort when providing fuel with a pump arrangement according to the preamble of claim 1 in a fuel injection system of a motor vehicle with an internal combustion engine.

The object is in a pump arrangement with at least one main feed pump for fuel, which comprises a pump piston which can be moved back and forth and which is driven by a camshaft via a tappet device which can be moved back and forth translationally into an annular space radially outside the pump piston Is rotatable about an axis of rotation in an engine room of a pump housing body, and with an auxiliary feed pump, the plunger device being used as a displacer of the auxiliary feed pump and the annular space radially outside the pump piston as an auxiliary pump chamber, in that the auxiliary feed pump is designed as a lubricant pump. A different medium, such as oil, is not used as the lubricant. In motor vehicles, especially in commercial vehicles, such as trucks, oil-lubricated fuel pumps are often arranged in the back of the supply chain in an engine oil circuit. Among other things, this can mean that when the engine is started it takes a while for the fuel pump to be supplied with lubricant, in particular with oil. The claimed pump arrangement provides the advantage that the fuel pump, ie the main feed pump of the pump arrangement, supplies itself with lubricant via the auxiliary feed pump.

A preferred exemplary embodiment of the pump arrangement is characterized in that the auxiliary pump chamber is assigned a lubricant inlet region and a lubricant outlet region. Lubricant, in particular oil, is advantageously sucked into the auxiliary pump chamber via the lubricant inlet area. The suctioned lubricant is pressurized in the auxiliary pump chamber by the plunger device, which can be moved back and forth. The pressurized lubricant then exits the auxiliary pump chamber through the lubricant outlet area.

Another preferred exemplary embodiment of the pump arrangement is characterized in that a check valve is arranged in each case in the lubricant medium inlet area and in the lubricant medium outlet area. The check valve in the lubricant inlet area opens in the direction of the auxiliary pump chamber and blocks in the opposite direction. The check valve in the lubricant outlet area locks in the direction the auxiliary pump chamber and opens in the opposite direction. This ensures continuous operation of the auxiliary feed pump as a lubricant pump in a simple manner.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the lubricant medium inlet region and the lubricant medium outlet region are designed as lubricant medium channels in the pump housing body. This reduces the manufacturing effort.

A further preferred exemplary embodiment of the pump arrangement is characterized in that the lubricant medium outlet area is connected to two slide bearings for the camshaft via lubricant medium channels. As a result, the service life of the pump arrangement is easily extended. The lubricant medium channels can advantageously be equipped with hydraulic resistors, for example in the form of throttle bores, in order to reduce the flow rate if necessary.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the tappet device is designed as a roller tappet with a roller that is rotatably supported by a hydrodynamic bearing in a roller shoe, which comprises at least one lubricant medium channel, through the lubricant from the auxiliary pump chamber to the hydrodynamic bearing in the roller shoe. This can further extend the life of the pump assembly. The lubricant medium channel can advantageously be equipped with a hydraulic resistor, for example in the form of a throttle bore, in order to reduce the flow rate, if necessary.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the engine compartment comprises a lubricant sump with a lubricant outlet. The lubricant reaches the lubricant sump, for example, via the hydrodynamic bearing of the roller in the roller shoe. Excess lubricant can be fed to a central lubricant sump of the internal combustion engine via the drain, for example.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the pump arrangement is designed as a radial piston pump. The radial piston pump is designed or similar to a conventional radial piston pump. The radial piston pump comprises, for example, two or more pump elements. For example, the two pump elements can be arranged essentially in a V-shape.

Another preferred exemplary embodiment of the pump arrangement is characterized in that the pump arrangement is designed as an in-line piston pump. The in-line piston pump comprises, for example, two pump elements arranged in series, which are driven by a common camshaft.

The invention further relates to a pump housing body and / or a roller shoe for a pump arrangement described above. The parts mentioned can be traded separately.

Further advantages, features and details of the invention emerge from the following description, in which various exemplary embodiments are described in detail with reference to the drawing.

list of figures

• 1 eine Pumpenanordnung mit einer Hauptförderpumpe und einer Hilfsförderpumpe, die als Schmiermediumpumpe ausgeführt ist, im Schnitt;
• 2 eine ähnliche Pumpenanordnung wie in 1 mit einem hydrodynamischen Lager, das durch die Hilfsförderpumpe mit Schmiermedium versorgt wird;
• 3 eine ähnliche Pumpenanordnung wie in den 1 und 2 mit einer Nockenwelle, die durch zwei Gleitlager gelagert ist, die durch die Hilfsförderpumpe mit Schmiermedium versorgt werden;
• 4 eine ähnliche Pumpenanordnung wie in den 1 bis 3 in einer Ausführung als Reihenkolbenpumpe; und
• 5 die Ansicht eines Schnitts entlang der Linie V-V in 4.

Show it:

• 1 a pump arrangement with a main feed pump and an auxiliary feed pump, which is designed as a lubricant pump, in section;
• 2 a similar pump arrangement as in 1 with a hydrodynamic bearing that is supplied with lubricant by the auxiliary feed pump;
• 3 a similar pump arrangement as in the 1 and 2 with a camshaft, which is supported by two plain bearings, which are supplied with lubricant by the auxiliary feed pump;
• 4 a similar pump arrangement as in the 1 to 3 in a version as an in-line piston pump; and
• 5 the view of a section along the line V - V in 4 ,

Description of the embodiments

In the 1 to 5 are four embodiments of a pump arrangement 11 ; 21 ; 41 ; 51 shown in different sectional views. The same reference numerals are used to designate the same or similar parts. In order to avoid repetitions, the same or similar parts are essentially only described once.

The in the 1 to 3 Pump arrangement shown 11 ; 21 ; 41 is a radial piston pump with a housing 1 executed. The housing 1 includes a pump housing body 2 , the can be made in one part or in several parts. The radial piston pump comprises, for example, two pump elements 4 , which are arranged in a V-shape.

The pump element 4 includes a pump piston 5 that in a cylinder head 6 is guided to move back and forth. In the cylinder head 6 the pump piston limits 5 an element space 7 , Via a suction valve 8th is in operation of the pump assembly 1 ; 21 ; 41 Fuel into the element space 7 sucked.

The pump piston 5 is via a tappet device 9 with a drive cam 15 a camshaft 16 coupled. The ram device 9 is in an annulus 10 radially outside the pump piston 5 guided translationally back and forth. Therefore, the annulus 10 also as a guide space for the ram device 9 be designated.

The ram device 9 is as a roller tappet 12 with a roller shoe 13 executed. In the roller shoe 13 is a roller 14 with the help of a hydrodynamic bearing 29 rotatably mounted. On the roller 14 the drive cam engages 15 the camshaft 16 on. The camshaft 16 with the drive cam 15 is in an engine room 17 of the pump housing body 2 arranged.

The in the 1 to 3 Pump arrangement shown 11 ; 21 ; 41 is also referred to as a high-pressure fuel pump. During operation of the high-pressure fuel pump, there is a rotational movement of the camshaft 16 into a translational movement of the pump piston 5 converted to the fuel in the element space 7 to be pressurized. The high pressure fuel passes through a pressure valve located in an outlet area ( 36 in 3 ) from the element space 7 out.

The high pressure generation of the fuel is due to the translatory movement of the pump piston 5 reached that the volume of the element space 7 varies cyclically. The roller tappet 12 enables the translation of the rotational movement of the camshaft 16 into the translational movement of the pump piston 5 , The roller tappet transmits 12 the axial force of the pump piston 5 with low friction losses between the roller 14 and roller shoe 13 on the cam surface. The roller tappet 12 is inside the pump housing body 2 radially closely guided in order to be able to absorb the lateral forces arising from the cam engine for structural reasons.

The engine parts are advantageous in a lubricant sump 30 in the engine room 17 arranged. The auxiliary feed pump 19 includes an auxiliary pump chamber 20 that are in the annulus 10 from the plunger device which can be moved back and forth in translation 9 is limited. Over a lubricant inlet area 22 lubricant gets into the auxiliary pump chamber 20 ,

The lubricant inlet area 22 is as a lubricant channel 26 in the pump housing body 2 executed and with a check valve 24 fitted. Via a lubricant outlet area 23 the pressurized lubricant comes out of the auxiliary pump chamber 20 out. The lubricant outlet area 23 is as a lubricant channel 26 in the pump housing body 2 executed and with a check valve 25 fitted.

At the in 2 shown pump arrangement 21 is the roller shoe 13 with a lubricant channel 28 fitted. At the in 3 shown pump arrangement 41 are even two lubricant channels 37 . 38 in the roller shoe 13 shown. Via the lubricant channels 28 ; 37 ; 38 lubricant comes out of the auxiliary pump chamber 20 to the hydrodynamic bearing 29 the roller 14 , Excess lubricant passes through the roller 14 in the lubricant sump 30 ,

In 2 is by an arrow 31 indicated how excess lubricant through the lubricant drain 32 from the lubricant sump 30 in the engine room 17 exit. That about the lubricant drain 32 from the engine room 17 Leaking lubricant, for example, gets into an oil pan in the engine, where it is then sucked in again via an oil filter. Another lubricant channel 28 goes from the lubricant channel 27 out of the lubricant outlet area 23 in 2 represents. With an arrow 34 is in 2 indicated that lubricant from the lubricant channel 33 at various points in the pump arrangement 21 can be used for lubrication and / or cooling.

In 3 you can see that the drive shaft 16 the pump arrangement 41 with the help of two plain bearings 42 . 43 in the pump housing body 2 is rotatably mounted. The pump housing body 2 is in 3 executed in several parts. The plain bearing 43 is in the pump housing body 2 arranged. The plain bearing 42 is in an additional body 44 arranged.

The additional body 44 is fixed to the pump housing body 2 connected. A lubricant channel 39 extends through the pump housing body 2 and the additional body 44 to the plain bearing 42 , The lubricant channel 39 goes like in 3 is indicated by a lubricant channel 40 out. The lubricant channel 40 in turn goes from the lubricant channel 27 in the lubricant outlet area 23 out. The Lubricating medium channel 40 extends from the lubricant medium channel 27 to the plain bearing 43 ,

The lubricant channels 39 . 40 are advantageous in front of the plain bearings 42 . 43 equipped with a throttle bore to reduce the flow rate. The lubricant channels are for the same purpose 37 . 38 in the roller shoe 13 equipped with throttle bores. With an arrow 45 is in 3 indicated that this is from the lubricant outlet area 23 escaping lubricant can be used to supply other consumers with lubricant. The other consumers are, for example, engine mounts of the internal combustion engine.

The in the 4 and 5 Pump arrangement shown 51 is as an in-line piston pump or in-line pump with two pump elements 52 . 53 executed. The two pump elements 52 . 53 are arranged adjacent in the axial direction. The pump arrangement 51 comprises a multi-part pump housing body 50 , Apart from the design as an in-line piston pump, the pump arrangement is similar 51 the pump arrangements 11 ; 21 and 41 in the 1 to 3 ,

In 4 you can see that a pestle device 54 of the pump element 52 is not a displacer of an auxiliary feed pump. Only one pusher device 55 of the pump element 53 works as an auxiliary feed pump 49 with an auxiliary pump chamber 70 , The auxiliary feed pump 49 with the auxiliary pump chamber 70 corresponds in structure and function to the auxiliary feed pump 19 in the 1 to 3 ,

In 5 you can see that the auxiliary pumping chamber 70 a lubricant inlet area 56 assigned. The lubricant inlet area 56 includes a lubricant channel 66 , In the lubricant channel 66 is a check valve 58 arranged. In 4 you can see that the auxiliary pump chamber 70 a lubricant outlet area 57 assigned. The lubricant outlet area 57 includes a lubricant channel 67 , In the lubricant channel 67 is a check valve 59 arranged.

From the lubricant channel 55 in the lubricant outlet area 57 extends a lubricant medium channel 61 to a plain bearing 62 the camshaft 16 , From the lubricant channel 61 again a lubricant channel extends 60 to the plain bearing 62 the camshaft 16 ,

With the pump arrangement 51 become the roller bearings of the rollers of the tappet devices in the pump elements 52 . 53 not actively lubricated with lubricant. The roller bearings are lubricated when the pumps are arranged 51 only by panicking in the lubricant sump.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1184568 B1 [0002]

Claims (10)

Pump arrangement (11; 21; 41; 51) with at least one main feed pump (18) for fuel, which comprises a pump piston (5) which can be moved back and forth by means of a plunger device (9) which is located radially outside in an annular space (10) of the pump piston (5) can be moved back and forth in translation, is driven by a camshaft (16) which is arranged in an engine room (17) of a pump housing body (2; 50) and can be rotated about an axis of rotation, and with an auxiliary feed pump (19), wherein the plunger device (9) is used as a displacer of the auxiliary feed pump (19) and the annular space (10) radially outside the pump piston (5) as an auxiliary pump chamber (20), characterized in that the auxiliary feed pump (19) is designed as a lubricant pump. Pump arrangement after Claim 1 , characterized in that the auxiliary pump chamber (20) is assigned a lubricant inlet region (22; 56) and a lubricant outlet region (23; 57). Pump arrangement after Claim 2 , characterized in that a check valve (24, 25; 58, 59) is arranged in each case in the lubricant medium inlet area (22; 56) and in the lubricant medium outlet area (23; 57). Pump arrangement after Claim 2 or 3 , characterized in that the lubricant medium inlet area (22; 56) and the lubricant medium outlet area (23; 57) are designed as lubricant medium channels (26, 27; 66, 67) in the pump housing body (2; 50). Pump arrangement according to one of the Claims 2 to 4 , characterized in that the lubricant medium outlet area (23; 57) is connected via lubricant medium channels (39.40; 60.61) to at least one slide bearing (42.43; 62.63) for the camshaft (16). Pump arrangement according to one of the preceding claims, characterized in that the tappet device (9) is designed as a roller tappet (12) with a roller (14) which is rotatably supported by a hydrodynamic bearing (29) in a roller shoe (13) which at least comprises a lubricant medium channel (29; 37, 38) through which lubricant passes from the auxiliary pump chamber (20) to the hydrodynamic bearing (29) in the roller shoe (13). Pump arrangement according to one of the preceding claims, characterized in that the engine compartment (17) comprises a lubricant medium sump (30) with a lubricant medium outlet (32). Pump arrangement according to one of the preceding claims, characterized in that the pump arrangement (11; 21; 41) is designed as a radial piston pump. Pump arrangement according to one of the preceding claims, characterized in that the pump arrangement (51) is designed as an in-line piston pump. Pump housing body (2; 50) and / or roller shoe (13) for a pump arrangement (11; 21; 41; 51) according to one of the preceding claims.

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