DE102012215023A1 - Internal gear pump used as hydraulic pump for fuel injection system for motor car, has fluid storage space that is formed between radially outward facing surface of ring gear and radially inward facing surface of ring bearing - Google Patents

Abstract

The gear pump (10) has housing (12) that is provided with a receiving space (14). A ring bearing (30) is provided for rotatably supporting an inner spline ring gear (24) which is meshed with an outer spline pinion (22). The ring gear and axial washers are provided on both sides of pinion with respect to a drive axis (28). A fluid storage space (44) is formed between a radially outward facing surface (42) of ring gear and a radially inward facing surface (40) of ring bearing. A leakage region is arranged axial washers and ring gear along an axial direction.

Description

State of the art

The invention relates to an internal gear pump according to the preamble of claim 1.

From the DE 101 09 770 A1 an internal gear pump is known, with a housing, a rotating in the housing internally toothed ring gear and a rotatably mounted in the housing, meshing with the ring gear external gear. The ring gear is mounted by means of a bearing ring in the housing, wherein the bearing ring is received with play in the housing. The bearing ring is pivotable in the context of the available game about a parallel to the axes of the ring gear and the pinion pivot axis. The pivot axis is formed in the form of a pin, which simultaneously forms a safeguard against rotation of the bearing ring about its axis.

The above-described mounting of the bearing ring makes it possible to compensate for a radial gap which occurs in the region of the transition between the suction and pressure space between the teeth of the ring gear and the pinion. This compensation makes it possible to reduce a leakage current between the pressure chamber and the suction chamber. To seal the pressure chamber of the pump and to compensate for leakage currents occurring in the radial direction pinion and ring gear between two axial discs are added.

Disclosure of the invention

Object of the present invention is to provide an internal gear pump, which has a high overall efficiency.

This object is achieved by an internal gear pump with the features of claim 1.

Advantageous developments are specified in the subclaims. In addition, the invention features important features in the following description and in the drawing, wherein the features both alone and in different combinations may be important for the invention, without being explicitly referred to again.

According to the invention, a leakage current applied in the radial direction is used in order to fill a fluid storage space which is effective in the radial direction with fluid. The fluid storage space makes it possible to build a "pressure pad" of leakage fluid, which reduces the bearing friction forces acting between the ring gear and the ring bearing. Thus, a (unused in the prior art) leakage current to minimize friction of the bearing of the ring gear used and the mechanical efficiency and thus the overall efficiency of the internal gear pump can be increased. The minimization of friction between ring gear and ring bearing is also associated with a significant reduction in wear and thus with an increase in the life of the internal gear pump.

It is particularly preferred if the fluid storage space extends along the circumference of the ring gear only over part of the circumference. In this way, a locally limited "fluid cushion" can be created, which is the load distribution of the ring gear customizable.

For example, the fluid storage space extends along the circumference of the ring gear at the level of a pressure space formed between the teeth of the ring gear and the pinion. In this way, a compressive force which presses the ring gear at the level of the pressure chamber radially outward against the ring bearing, at least partially compensated and thus a corresponding bearing load can be reduced.

A compact and easy to produce fluid storage space results when it is formed in the form of a ring segment whose volume is limited by at least one provided in the ring bearing Materialausnehmung.

Preferably, the leakage area is bounded radially outwardly by an annular fluid collecting space. This allows a defined discharge of leakage fluid from the fluid collection chamber.

The fluid collecting space is preferably designed in the form of a groove whose volume is limited by at least one material recess, which is provided in a side surface of the ring gear and / or one of the side surface of the ring gear facing surface of the at least one axial disc. Thus, an annular fluid collecting space can be provided in a simple manner.

It is furthermore preferred if a fluid distributor space which can be supplied with leakage fluid is provided, which extends along the circumference of the ring gear and is connected in a fluid-effective manner to the fluid storage space. This makes it possible to feed a limited fluid storage space along the circumference irrespective of a rotational position of the ring gear with leakage fluid.

A particularly simply constructed fluid distribution space results when it is formed in the form of a groove whose volume is limited by at least one material recess, which in the Outer surface of the ring gear and / or is provided in the bearing surface of the ring bearing.

A particularly space-saving arrangement results when the fluid-effective connection between the leakage area and the fluid storage space comprises at least one fluid line formed in the ring gear. These fluid lines may be formed for example in the form of bores or bore sections.

In a further preferred embodiment of the invention, it is provided that the leakage region and a pressure chamber formed between the toothings of the ring gear of the pinion are fluidically connected to one another by means of an additional leakage line. This makes it possible to ensure that the leakage area is supplied with a minimum amount of leakage fluid. The leakage line can be formed, for example, in the form of a groove which extends in the radial direction between the pressure chamber and the leakage chamber, preferably up to a possibly existing fluid collection chamber.

The internal gear pump according to the invention is particularly well suited for use in fuel injection systems for motor vehicles or aircraft, for hydraulic pumps of mobile or stationary working hydraulics, as a pump for use in brake, steering, anti-skidding or antisliding systems for motor vehicles, as an oil pump for internal combustion engines, as oil pumps and as oil additive pumps for shift, dual clutch, automatic and CVT transmissions, as a feed fluid pump, as a coolant pump (especially for thermal management in vehicles) and as a water pump in solar technology.

Hereinafter, an embodiment of the invention will be explained with reference to the drawings. In the drawing shows:

1 a side view of an embodiment of an internal gear pump;

1 a view of the internal gear pump according to 1 along a in 1 sectional plane designated II-II; and

3 a view of the internal gear pump according to 1 along a in 1 III-III cutting plane.

An embodiment of an in 1 total with the reference numeral 10 designated internal gear pump comprises a housing 12 with a cylindrical receiving space 14 ,

On the case 12 is an anti-rotation element 16 in the form of a bolt 18 fixed. The bolt 18 projects with a section radially inward into the receiving space 14 ,

The internal gear pump 10 includes a drive shaft 20 for arranging a pinion 22 , which with a ring gear 24 combs.

The pinion 22 and the ring gear 24 are by means of axial discs 26 in relation to an axis 28 the drive shaft 20 axially aligned relative to each other. The axial discs 26 are related to the drive axle 28 on opposite sides of the pinion 22 and the ring gear 24 arranged (cf. 2 ).

For storage of the ring gear 24 in the housing opening 14 is a total with the reference numeral 30 designated ring bearing provided.

The ring bearing 30 has a part-circular recess 32 on, which for the arrangement of that portion of the bolt 18 Serves radially inward into the receiving space 14 protrudes.

During operation of the internal gear pump 10 becomes the pinion 22 by means of the drive shaft 20 around the drive axle 28 driven, for example in a clockwise direction. As a result, in a conventional manner, a fluid from a suction chamber 34 in a pressure room 36 transfer. In a transition area 38 between suction chamber 34 and pressure room 36 should the facing teeth of the pinion 22 and the ring gear 24 with the formation of the smallest possible radial gap sealingly abut each other. This is achieved by the fact that the ring bearing 30 with game in by the housing 12 trained boundary of the reception room 14 is included. When the pressure room 36 is pressurized, the ring bearing 30 according to the direction of a resultant 39 pressed radially outward. This will cause the bolt 18 one on the ring bearing 30 acting torque generated so that the ring bearing 30 in the transition area 38 is pivoted radially inward.

The ring bearing 30 has a radially inwardly facing, cylindrical bearing surface 40 on, which for the storage of a radially outwardly facing outer surface 42 of the ring gear 24 serves.

The internal gear pump 10 includes a ring-segment-shaped fluid storage space 44 , This is for example in the form of one in the ring bearing 30 formed material recess formed. The fluid storage room 44 extends in the circumferential direction of the ring gear 24 seen, only over a portion of the circumference, preferably over an extension angle of between about 10 degrees and 90 Degrees, in particular between about 10 degrees and 60 degrees.

In the circumferential direction of the ring gear 24 seen is the fluid storage space 44 at the height of the pressure chamber 36 arranged. In the fluid storage room 44 stored leakage fluid relieves the storage of the ring gear 24 in the ring camp 30 at the height of the pressure chamber 36 , especially at the level of the resultant 38 ,

To the fluid storage room 44 to be able to fill with fluid, leakage fluid is used, which from the pressure chamber 36 in a leakage area 46 passes, which in the radial direction between an axial disc 26 and the ring gear 24 is provided. The leakage areas 46 are each between the axial discs 26 facing side surfaces 48 of the ring gear 24 and between these side surfaces 48 facing surfaces 50 the axial discs 26 limited. Radially outward are the leakage areas 46 by means of a respective annular fluid collecting space 52 limited. The fluid collection rooms 52 are formed for example in the form of grooves which in the side surfaces 48 and / or in the areas 50 the axial discs 26 are formed.

To the fluid collection room 52 close in the ring gear 24 provided fluid lines 54 at. For example, a first line section 56 provided, which on opposite sides of the ring gear 24 arranged fluid collection rooms 52 connects with each other. The pipe section 56 is with a running in the radial direction line section 58 connected to an annular fluid distribution chamber 60 empties. The fluid distribution chamber 60 is in particular along the entire circumference of the outer surface 42 of the ring gear 24 intended. Seen in the axial direction is the fluid distribution chamber 60 arranged so that it communicates with the fluid storage space 44 (Which is only over part of the circumference of the ring gear 24 extends) is aligned. In this way, regardless of the rotational position of the ring gear 24 Ensures that leakage fluid from the leakage area 46 over the fluid collecting rooms 52 , the fluid lines 54 and the fluid distribution chamber 60 in the fluid storage room 44 can get.

To further assist the delivery of leakage fluid into the fluid storage space 44 can be an extra leakage line 62 (see. 2 ), which are in the radial direction through the ring gear 24 extends through and the pressure chamber 36 with the leakage area 46 and / or with the fluid collection chamber 52 combines. The leakage line 62 should have a very small cross-section and has, for example, a width of only 0.2 millimeters and a depth of only 10 to 15 microns. Such a leakage line, for example, by laser processing of the side surface 48 of the ring gear 24 and / or the area 50 an axial disc 26 getting produced.

It is understood that the fluid collection rooms 52 also at least proportionally in the axial discs 26 may be formed and / or that the fluid distribution space 60 as a material recess in the ring bearing 30 can be trained. When the fluid collection rooms 52 exclusively in the axial discs 26 trained and the fluid distribution chamber 60 in the ring camp 30 is formed, it is sufficient, the ring gear 24 with fluid lines 54 to provide.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely 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.

Cited patent literature

• DE 10109770 A1 [0002]

Claims (10)

Internal gear pump ( 10 ), with a housing ( 12 ), in which a receiving space ( 14 ), wherein a ring bearing ( 30 ) with play in the recording room ( 14 ) and by means of an anti-rotation element ( 16 ) on the housing ( 12 ) is secured against rotation, wherein the ring bearing ( 30 ) for the rotatable mounting of an internally toothed ring gear ( 24 ), which with an externally toothed pinion ( 22 ) meshes, wherein with respect to a drive axle ( 28 ) of the pinion ( 22 ) on both sides of the pinion ( 22 ) and the ring gear ( 24 ) Axial discs ( 26 ) are provided, characterized in that in the region of a radially outwardly facing outer surface ( 42 ) of the ring gear ( 24 ) and a radially inwardly facing bearing surface ( 40 ) of the ring bearing ( 30 ) a fluid storage space which can be supplied with leakage fluid (US Pat. 44 ), which fluid-effectively with a in the axial direction between at least one of the axial discs ( 26 ) and the ring gear ( 24 ) arranged leakage area ( 46 ) connected is. Internal gear pump ( 10 ) according to claim 1, characterized in that the fluid storage space ( 44 ) along the circumference of the ring gear ( 24 ) extends only over part of the circumference. Internal gear pump ( 10 ) according to any one of the preceding claims, characterized in that the fluid storage space ( 44 ) along the circumference of the ring gear ( 24 ) seen at the level of one between the teeth of the ring gear ( 24 ) and the pinion trained pressure chamber ( 36 ) is arranged. Internal gear pump ( 10 ) according to any one of the preceding claims, characterized in that the fluid storage space ( 44 ) is formed in the form of a ring segment whose volume through at least one in the ring bearing ( 30 ) provided material recess is limited. Internal gear pump ( 10 ) according to one of the preceding claims, characterized in that the leakage area ( 46 ) radially outward through an annular fluid collection space ( 52 ) is limited. Internal gear pump ( 10 ) according to claim 5, characterized in that the fluid collecting space ( 52 ) is formed in the form of a groove whose volume is delimited by at least one material recess, which in a side surface ( 48 ) of the ring gear ( 24 ) and / or one of the side surfaces ( 48 ) of the ring gear ( 24 ) facing surface ( 50 ) of the at least one axial disc ( 26 ) is provided. Internal gear pump ( 10 ) according to one of the preceding claims, characterized in that a fluid distribution space ( 60 ) is provided, which along the circumference of the ring gear ( 24 ) and with the fluid storage space ( 44 ) is fluidically connected. Internal gear pump ( 10 ) according to claim 7, characterized in that the fluid distribution chamber ( 60 ) is formed in the form of a groove, whose volume is delimited by at least one material recess, which in the outer surface ( 42 ) of the ring gear ( 24 ) and / or in the storage area ( 40 ) of the ring bearing ( 30 ) is provided. Internal gear pump ( 10 ) according to one of the preceding claims, characterized in that the fluid-effective connection between the leakage area ( 46 ) and fluid storage space ( 44 ) at least one in the ring gear ( 24 ) formed fluid line ( 54 ). Internal gear pump ( 10 ) according to one of the preceding claims, characterized in that the leakage area ( 46 ) and between the teeth of the ring gear ( 24 ) and the pinion trained pressure chamber ( 36 ) by means of an additional leakage line ( 62 ) are fluidically interconnected.

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