WO2014009224A1

WO2014009224A1 - High-pressure pump

Info

Publication number: WO2014009224A1
Application number: PCT/EP2013/064061
Authority: WO
Inventors: Ngoc-Tam Vu
Original assignee: Continental Automotive Gmbh
Priority date: 2012-07-10
Filing date: 2013-07-03
Publication date: 2014-01-16
Also published as: EP2872778B1; EP2872778A1; DE102012211976B3

Abstract

The invention relates to a high-pressure pump (10) for delivering a fluid, having a pump housing (12), a shaft element (15) which extends in the direction of a longitudinal axis (Z) and is mounted in a housing recess (13) of the pump housing (12), a drive shaft (16) which is mounted rotatably on the shaft element (15), and a drive element (40) which is coupled fixedly to the drive shaft (16) and is configured for driving the drive shaft (16). The high-pressure pump (10) has a bearing element (46) which is coupled fixedly to the pump housing (12) or is configured integrally with the pump housing (12), and which has a recess (48), in which the shaft element (15) is mounted. The recess (48) of the bearing element (46) is arranged relative to the housing recess (13) in such a way that the drive element (40) is arranged axially between the recess (48) of the bearing element (46) and the housing recess (13).

Description

description

high pressure pump

The invention relates to a high-pressure pump.

Preferably, such a high-pressure pump is used as a pump for delivering fluid for a storage injection system for internal combustion engines of motor vehicles.

Storage injection systems for internal combustion engines of motor vehicles, for example in common-rail systems, should be able to provide the necessary volume flow and the required fluid pressure. The high-pressure pump is subject to strong loads in memory injection systems for motor vehicles, in particular mechanical stresses. In particular, large forces must be able to be absorbed by such high-pressure pumps. This places high demands on the material as well as on the construction of the high pressure pump.

Since high-pressure pumps are exposed to pressures of up to more than 2000 bar, for example, they have to withstand high stresses.

The object of the invention is to sheep ^¬ fen a high-pressure pump, which allows reliable and precise operation even under heavy mechanical stresses. At the same time, the high-pressure pump should be inexpensive to produce.

The object is solved by the features of the independent claim. Advantageous embodiments of the invention are characterized in the subclaims. The invention is characterized by a high-pressure pump for delivering a fluid, with a pump housing, extending in the direction of a longitudinal axis axle member which is mounted in a housing recess of the pump housing, a rotatably mounted on the axle drive shaft, and a fixedly coupled to the drive shaft Drive element, which is designed to drive the drive shaft. The high-pressure ^¬ pump has a bearing element which is fixedly coupled to the pump housing or formed integrally with the pump housing, and having a recess in which the axle is mounted. The recess of the bearing element is arranged relative to the housing recess such that the drive element axially between the recess of the bearing element and the

Housing recess is arranged.

This has the advantage that a very precise alignment of the shaft element can be achieved. This is especially true when large forces are transmitted from the drive element via the drive shaft to the axle. Furthermore, it can be achieved that only a slight wear on the axle and the drive shaft occurs. It can thus be achieved that the drive power required to overcome the frictional forces is small.

In an advantageous embodiment, the drive element extends substantially in a plane perpendicular to the longitudinal axis. In the plane radially between the axle and the drive shaft, a sliding bearing is arranged. This has the advantage that the sliding bearing lies in the plane in which the forces of the drive element act. This can be avoided that edges of components of the high-pressure pump act on the sliding bearing. Thus, the plain bearing allow low friction between the axle and the drive shaft, too when the forces exerted by the drive element on the drive shaft and the axle element are large.

In a further advantageous embodiment, the high-pressure pump has at least one pump unit which can be driven by the drive shaft and which extends essentially in a further plane perpendicular to the longitudinal axis. The further plane is arranged axially between the recess of the bearing element and the housing recess. This has the advantage that a very precise alignment of the shaft element can be achieved. This is especially true when large forces are transmitted from the drive shaft to the pump unit. The wide ^¬ ren can be achieved that only a slight wear on the axle and the drive shaft occurs. Thus, it can be ^¬ enough that the required for overcoming the frictional forces drive power is small.

In a further advantageous embodiment is arranged in the further plane radially between the axle and the drive shaft ^¬ at least one further sliding bearing. This has the advantage that the further sliding bearing lies in the plane in which the forces of the pump unit also act. Thus, the sliding bearing allow a low friction between the axle and the drive shaft, even if the forces between the drive shaft and the axle are large.

In a further advantageous embodiment, this is

Bearing element formed as a bracket, which is coupled to a first Bügelab ^{¬ section} fixed to the pump housing. The Lagerele ^¬ ment has at one with respect to the first bracket portion distal the second strap portion on the recess of the bearing element. This has the advantage that the high pressure pump can be easily constructed. This allows the high pressure pump to be easy to assemble and thus be manufactured at low cost. Embodiments of the invention are explained in more detail below with reference to the schematic drawings. Show it:

Figure 1 is a partially sectioned, partially perspective

View of a high pressure pump, and Figure 2 is a detail view of the high pressure pump.

Elements of the same construction or function are

cross-figure provided with the same reference numerals. 1 shows a high pressure pump 10 with a pump housing 12. The pump housing 12 is preferably formed wholly or partly of a metal. The pump housing 12 is in the illustrated embodiment in two parts from a first part 12 a and a second part 12 b executed. The first part 12 a is in particular pot-shaped. The second part 12 b is formed in particular as a flange. However, the pump housing 12 may also be made in one piece or have more than two parts. In the embodiment illustrated here, the high-pressure pump 10 has a pump unit 14. In other embodiments, however, the high-pressure pump 10 may also have two or more pump units.

The high-pressure pump 10 has centrally an axle 15. The shaft element 15 has a longitudinal axis Z. The pump housing 12 has a housing recess 13. The axle element 15 is mounted in the housing recess 13.

The second part 12b of the pump housing 12 designed as a flange is firmly connected to the first part 12a of the pump housing 12. pelt. The axle 15 is in operative connection with a drive shaft 16 designed as a camshaft. Instead of the drive shaft 16 designed as a camshaft, an eccentric shaft can also be used.

The pump unit 14 essentially consists of a cylinder housing 17 coupled to the pump housing 12, a cylinder chamber 18 arranged in the cylinder housing 17, a spring 20 and a high-pressure piston 21. The cylinder housing 17, the cylinder chamber 18, the high-pressure piston 21 and the spring 20 are mutually aligned arranged coaxially.

The high-pressure piston 21 is mounted axially movable in the cylinder chamber 18 of the cylinder housing 17. The high-pressure piston 21 is held in constant operative connection with the drive shaft 16 by means of the spring 20, which is preferably supported on the cylinder housing 17 and cooperates with the high-pressure piston 21.

In order to be able to fill the cylinder chamber 18 with fluid, the cylinder housing 17 has a supply line 22, in which preferably an inlet valve 24 is arranged. The inlet valve 24 facilitates the filling of the cylinder chamber 18 and prevents the backflow of the fluid from the feed line 22 during the compression phase. The cylinder housing 17 further has a drain line 26 and an outlet valve 28 arranged therein. Via the drain line 26 and the outlet valve 28, the fluid can be ejected from the cylinder chamber 18.

In the embodiment shown here, the pump unit 14 has a roller tappet 32 coupled to the high pressure piston 21. The roller tappet 32 is operatively connected to the drive shaft 16 via a cylindrical roller 30. In alternative embodiments, the pump unit 14 may also be used be formed with an eccentric ring and coupled to the high pressure piston shoe.

Radial between the axle 15 and the drive shaft 16, a sliding bearing 36 and a further sliding bearing 38 are arranged. In further embodiments, more than two plain bearings between the axle 15 and the drive shaft 16 can be angeord ^¬ net. The sliding bearings 36, 38 allow that only a slight friction between the shaft member 15 and the drive shaft 16 occurs, even if the forces occurring between the axle 15 and the drive shaft 16 are large.

The high-pressure pump 10 further has a drive element 40. The drive element 40 is fixedly coupled to the drive shaft 16. The drive element 40 is preferably designed as a belt pulley or as a sprocket.

On the drive shaft 16 in particular a nut 42 is arranged with a thread 44. By means of the mother 42, the

Drive element 40 to be fixedly coupled to the drive shaft 16. This can be avoided in particular a displacement or tilting of the drive member 40 relative to the axle 15 and the drive shaft 16. The high-pressure pump 10 also has a bearing element 46. The bearing element 46 is fixedly coupled to the pump housing 12. In an alternative embodiment, the bearing element 46 may also be formed integrally with the pump housing. The bearing element 46 has a recess 48. Particularly preferably, the bearing element 46 is formed as a bracket. The trained as a bracket bearing element 46 has a first bracket portion 50. The first bracket portion 50 is fixedly coupled to the pump housing 12. The bearing element 46 embodied as a bracket has a second bracket that is distal with respect to the first bracket section 50. section 52. In the second bracket portion 52, the recess 48 is arranged. The bearing element 46 further has a Zwischenab ^{¬ section} 54, which connects the first bracket portion 50 with the second bracket portion 52. Preferably, the bearing member 46 of the first bracket portion 50, the second bracket portion 52 and the intermediate portion 54 is integrally formed.

The axle element 15 is mounted in the recess 48 of the bearing element 46. The drive element 40 is arranged axially between the recess 48 and the housing recess 13. This has the advantage that a very precise alignment of the shaft member 15 can be achieved. Become particular of the

Drive element 40 large forces transmitted via the drive shaft 16 to the axle 15, so secure storage of the shaft member 15 in the pump housing 12 and in the bearing element 46 can be achieved. Thus, a slight wear on the axle 15 and on the drive shaft 16 can be achieved. This can also be achieved that required for overcoming the frictional forces drive power for

High pressure pump 10 can be small.

The drive member 40 extends substantially in a plane El, which is perpendicular to the longitudinal axis z. Thus, a stable mounting of the shaft member 15 and the drive shaft 16 can be achieved even with large acting in the direction of the plane El forces of the drive member 40. By means of the sliding bearing 36 can be further achieved that a low friction between the shaft member 15 and the drive shaft 16 occurs, even if the outgoing of the drive member 40 forces on the drive shaft 16 and the shaft member 15 are large.

The pump unit 14 extends substantially in a further plane E2 perpendicular to the longitudinal axis Z. The other sliding bearing 38 is radially between the shaft member 15 and the Drive shaft 16 arranged in the further plane E2. The other sliding bearing 38 is thus in the further plane E2, in which the forces of the pump unit 14, in particular of the high-pressure piston ^¬ 21 act. It is thus possible to achieve that the further sliding bearing 38 only leads to a low friction between the axle element 15 and the drive shaft 16. This is true even if the forces between the drive shaft 16 and the shaft member 15 are large. In the drive shaft 16, a lubricant supply passage 56 is formed, by means of which it is possible, in particular a space between the shaft member 15 and the drive shaft 16, in which the sliding bearings 36, 38 are arranged to rinse with a lubricant. By flushing the space between the axle 15 and the drive shaft 16, cooling and lubrication of the high-pressure pump 10 can be effected. The lubricant can be at ^¬ closing discharged from the space between the axle 15 and the drive shaft 16 preferably via the drive shaft 16 and the pump housing 12 via a lubricant return passage 58 from the high pressure pump 10 degrees.

FIG. 2 shows a detailed view of parts of the high-pressure pump 10. In particular, the drive element 40 embodied as a belt pulley or as a sprocket is shown, which is coupled to a transmission element 60. About the

Transmission element 60, a driving force, for example, from the internal combustion engine to the drive member 40 are transmitted. The transmission element 60 is preferably entspre ^¬ accordingly designed as a belt or a chain forming the drive element 40th Furthermore, Figure 2 shows the trained as a bracket bearing element 46, in which the axle 15 is mounted. Preferably, the bearing element 46 is fastened by means of fastening elements 62 ^¬ to a motor housing, not shown. In the following, the function of the high pressure pump 10 will be described with reference to Figures 1 and 2: By a rotational movement of the drive shaft 16, a suction stroke is performed first, that is, a movement of the high pressure ^¬ piston 21 in the direction of the longitudinal axis z of the shaft member 15 out. In this case, fluid from the supply line 22 via the

Inlet valve 24 is conveyed into the cylinder chamber 18, wherein the exhaust valve 28 is closed. By a further rotation of the drive shaft 16, a pumping stroke is then performed, that is, a movement of the high pressure piston 21 from the longitudinal axis Z of the shaft member 15 away. In this case, the fluid in the cylinder chamber 18 is compressed or discharged via the outlet valve 28 under high pressure, the inlet valve 24 being closed. If the high-pressure pump 10 is a high-pressure fuel pump, for example

Injection system of an internal combustion engine, so the pressurized fluid at high pressure can reach a high-pressure fuel storage, the so-called common rail.

About the transmission element 60 are in the plane El

Tension forces Fg resulting in a lateral force FQ on the

Drive element 40 exercised. By the storage of the shaft member 15 in the recess 48 of the bearing member 46 and the

Housing recess 13 can be achieved, that the transverse force FQ is in particular also absorbed by the bearing element 46, and so a precise storage of the shaft member 15 and the

Drive shaft 16 is reached. This applies correspondingly to the forces exerted by the high-pressure piston 21 on the drive shaft 16 and the axle element 15 transverse to the longitudinal axis z in the further plane E2. The arrangement of the plain bearings 36, 38 in the planes El, E2 radially between the axle 15 and the drive shaft 16 can further be avoided that the slide bearings 36, 38 with respect to the axle 15 and the drive shaft 16 tilt. Thus, the wear on the axle 15 and the drive shaft 16 can be kept low. Thus, a small friction between the axle 15 and the drive shaft 16 can be achieved. Furthermore, by constructing the high-pressure pump 10 with the bearing element 46, in the recess 48 of which the axle element 15 is mounted, the high-pressure pump 10 can be formed as a compact unit. At the high-pressure pump 10, a defined interface for the customer can be provided.

Reference sign list

10 high pressure pump

12 pump housings

12a, 12b parts of 12

13 housing recess

14 pump unit

15 axis element

16 drive shaft

17 cylinder housing

18 cylinder combs

20 spring

21 high pressure pistons

22 supply line

24 inlet valve

26 drain line

28 exhaust valve

30 roll

32 roller tappets

36 plain bearings

38 other plain bearings

40 drive element

42 mother

44 thread

46 bearing element

48 recess of 46

50 1. bracket section

52 2nd bracket section

54 intermediate section

56 Lubricant inlet channel

58 lubricant return channel

60 transmission element (belt / chain)

62 fastener Planes longitudinal axis

Tension forces shear force

Claims

claims

1. High-pressure pump (10) for conveying a fluid, with

a pump housing (12),

a shaft element (15) extending in the direction of a longitudinal axis (Z) and mounted in a housing recess (13) of the pump housing (12),

- One on the axle (15) rotatably mounted drive shaft (16), and

- a fixed manner to the drive shaft (16) coupled to the drive ^¬ element (40) which is configured to drive the drive shaft (16),

wherein the high-pressure pump (10) has a bearing element (46) which is fixedly coupled to the pump housing (12) or formed integrally with the pump housing (12) and which has a recess (48) in which the axle element (15) is mounted is, and wherein the recess (48) of the bearing element (46) relative to the hous ^¬ eususnehmung (13) is arranged such that the drive ^¬ element (40) axially between the recess (48) of the bearing element (46) and the housing recess (13) is arranged.

2. High-pressure pump (10) according to claim 1, wherein the drive element (40) extends substantially in a plane (El) perpendicular to the longitudinal axis (Z), and in the plane (El) radially between the axle (15) and the Drive shaft (16) a sliding bearing (36) is arranged.

3. High-pressure pump (10) according to claim 1 or 2, wherein the high-pressure pump (10) comprises at least one of the

Drive shaft (16) drivable pump unit (14) which extends substantially in a further plane (E2) perpendicular to the longitudinal axis (Z), wherein the further plane (E2) axially between the recess (48) of the bearing element (46) and the housing recess (13) is arranged.

4. High-pressure pump (10) according to claim 3, wherein in the further plane (E2) radially between the axle element (15) and the drive shaft ^¬ (16) at least one further sliding bearing (38) is arranged.

5. High-pressure pump (10) according to one of the preceding

Claims, wherein the bearing element (46) is formed as a bracket which at a first bracket portion (50) fixed to the

Pump housing (12) is coupled, and the bearing element (46) at a relative to the first bracket portion (50) distal second bracket portion (52) has the recess (48) of the bearing element (46).