DE102007054808A1 - Pump assembly for synchronous pressurization of two fluid circuits - Google Patents

Abstract

The invention relates to a pump assembly (10) for the synchronous pressurization of two fluid circuits, which comprises two internal gear pumps (11, 11 ') rotatably driven via their drive shaft (16) and arranged together in a pump housing (12), whose pinion gears (19, 19') lie in the associated pump chamber and in meshing engagement with its ring gear (21, 21 '), wherein the pump chambers of the internal gear pumps (11, 11') by a common partition (15) are partitioned from each other, which is designed as a separate housing part and in a hollow cross-section a housing part (13) forming the peripheral wall of one of the internal gear pumps (11, 11 '), and suction channels (24, 24') and pressure channels (25, 25 ') associated with the internal gear pumps (11, 11') following an axial length in FIG the lateral boundary wall of the associated pump chamber in a radially extending in the pump housing (12) extending longitudinal section. According to the invention, the suction channel (24, 24 ') and the pressure channel (25, 25') of one of the internal gear pumps (11, 11 ') are integrated in the dividing wall (15).

Description

State of the art

The The invention relates to a pump assembly for synchronous pressurization of two fluid circuits according to the genus of the independent Patent claim 1.

Such a pump assembly is z. B. from the DE 10053991 A1 known as a so-called pump insert for a hydraulic, wheel slip-controlled vehicle brake system, being supplied by the two internal gear pumps of the pump insert different brake circuits of the brake system with diagonal brake circuit distribution. The two internal gear pumps are separated from each other by a separately formed partition wall of the multi-part housing and are traversed transversely by a common drive shaft. On this drive shaft, the pinion of the two gear pumps are pushed and rotatably connected via a driver connection with her. In order to seal the pump chambers of the adjacent gear pumps against each other, two shaft seals are inserted into matched annular spaces of the partition bore at a distance from each other. If something passes through the thus sealed at both ends shaft passage some brake fluid, it is removed via a vent hole, which is arranged between the shaft seals under radial extent in the partition wall. To integrate the two internal gear pumps in the respective associated brake circuit, each internal gear pump is further associated with a suction channel and a pressure channel, which are seen in the axial direction at opposite end portions of the pump assembly, extending substantially radially and bending their end portion in the suction or pressure side of the associated pump room open. The belonging to the internal gear pump channel pairs have due to their lateral arrangement in addition to the front ends of the pump assembly ei nen considerable distance from each other, which must also be considered in the design and dimensioning of the pump housing.

Disclosure of the invention

The Inventive pump assembly with the features of the independent claim 1 has in contrast the advantage that the axial distance of the pairs with suction channel and Pressure channel of the internal gear pumps significantly reduced from each other can be. This allows a more compact design of the pump assembly be realized and possibly with a simplified version of Line system for the two fluid circuits go along. The suction channel and the pressure channel can also on technical easier to position accurately positioned in the partition, because the partition as an axial thrust washer for the wheelsets Pumps serves. So the partition is before installation in the pump housing accessible from all sides what z. B. a machining for generating or editing the hollow channels significantly easier. Also, the enclosing housing parts no longer at a distance from their front sides on the circumference the partition joined by means of rolled-up areas or the like but the division plane can run next to the partition wall and the annular end faces of the housing parts to be joined together can be joined on push. hereby can the connection intensity of the hollow cylindrical housing parts be substantially improved, so that the pump assembly is not the Insertion into a stabilizing pump housing needs.

By those listed in the dependent claims Measures and developments are advantageous embodiments and improvements in independent claim 1 specified pump assembly possible.

Especially Advantageously, the suction channels and the pressure channels Both internal gear pumps integrated into the partition. hereby are the pressure channels and the suction channels both Internal gear pumps very close to each other, which is a corresponding Compact design of the pump assembly makes possible. Becomes In addition, the leakage channel integrated into the partition, he can clearly be shortened and do not need its own outlet, when it enters a drain hole of one or both of the suction channels Dividing wall opens. Are all located directly on the pump rooms adjoining or with these flow-connected fluid channels of the pump assembly together with the leakage channel inside the dividing wall, then let yourself the fluid channels with little production effort fit exactly into the workpiece "dividing wall" or easily work on cast-in fluid channels.

The Partition can, despite the integration of two suction channels and two pressure channels have a relatively small thickness, when the four fluid channels are substantially in the same cross-sectional area of the Partition are arranged. For this to be possible, let each of the fluid channels in the partition by 90 degrees arranged offset from each other by the internal gear pumps of Pump assembly to be rotated 180 degrees against each other. This has the positive side effect that also in the opposite Direction acting compressive forces in the internal gear pumps largely cancel.

If in the line system one of the versor ing fluid circuits a valve assembly is provided, this arrangement can be integrated directly into the associated fluid channel of the partition. This valve arrangement may comprise one or two valves in one or both fluid circuits to be charged. A technically particularly useful equipment of the fluid circuits or the fluid circuits, each with two valves is present when a pressure relief valve in the suction channel or the suction channels of the partition wall and a pressure relief valve in the pressure channel or the pressure channels of the partition wall are arranged. For this valve arrangement thus an already existing space is used within the partition, so that it can be dispensed with an external arrangement of the valves in the system of the associated fluid circuit. This results in a corresponding space savings outside the pump assembly and possibly a simplification of the connected line system.

The Partition consists in a preferred embodiment a cylindrical disc with plane-parallel end faces, the perpendicular to the central longitudinal axis of the disc and each other run parallel, and is in a cylindrical hollow section of the associated housing part pressed. If the planing faces are ground, which is due to the disc shape cost-effective with high surface quality possible, they can be used directly as starting surfaces to serve for the gear sets. By pressing the disc in a cylindrical hollow section, z. B. with a Press fit, can be a position-securing mounting position the disc in the housing without additional fasteners to ensure. The press-in process must be done so that the radial ends of the fluid channels of the disc after the Pressing in to corresponding fluid channels in the housing aligned. By choosing a suitable interference fit may possibly one without additional sealant liquid-tight connection between the outer circumference of the disc and the inner circumference of the housing be created.

The Pressed partition can advantageously axially between each other opposite annular end faces of two housing parts be supported, wherein the outer diameter of a the housing parts the outer diameter of the partition largely corresponds. The adapted in the diameter of the partition tubular end portion can then, similar to the Partition, in the larger tubular end pressed or pushed the other housing part after which a telescopic length overlap the pipe ends. With sufficient axial security results through the assembly of the hollow housing parts and the partition a very stable composite.

Around a reliable seal of the tooth gaps of Wheelsets in the internal gear pumps on their from the partition wall To ensure opposite end faces, can be at the ends the pump assembly each a pressure piece from a usual for plungers Plastic material may be arranged on the front sides of the associated Wheel set on the one hand and on the opposite bore wall the pump space on the other hand is axially supported. Preferably are the plungers each with an associated Bearing sleeve for the drive shaft structurally combined, resulting in a desirable reduction in the number of parts in the pump assembly. The bearing sleeve itself can be formed integrally with the pressure piece and even form a plain bearing. Alternatively, the bearing sleeve However, a rolling bearing or bearing shells of a plain bearing record or enclose.

A advantageous embodiment of the invention is below illustrated by drawings and with reference to the Drawings described.

Brief description of the drawings

1 shows a schematic central longitudinal section through a pump assembly according to the invention.

2 shows a pump chamber of the pump assembly of 1 in side view.

3 shows a vertical section through a partition of the pump assembly according to the section line III-III in 1 ,

Embodiment of invention

How out 1 can be seen comprises a pump assembly 10 two internal gear pumps 11 and 11 ' , which lie side by side laterally and in a common pump housing 12 are arranged. When installed, the pump assembly is 10 Component of a pressure control device for a vehicle brake system, not shown, with diagonally split brake circuits, wherein the internal gear pumps 11 and 11 ' are each responsible for the pressure supply of one of the brake circuits in the course of known as such brake interventions for ABS or ESP applications. The common pump housing 12 is on the outside of two pot-like hollow housing parts 13 and 14 each composed of a pump space of the internal gear pump 11 respectively. 11 ' limit on three sides and are joined under length coverage of their end areas. Between these housing parts 13 and 14 is a partition 15 inserted as an internal housing part, which the pump chambers of the two internal gear pumps 11 and 11 ' bounded with its front pages on the fourth page. The partition 15 consists of a cylindrical disc with plane-parallel end faces, in a cylindrical hollow cross-section of the associated housing part 13 is pressed.

The drive of the two internal gear pumps 11 and 11 ' via a common drive shaft 16 , which is rotationally driven by an externally flanged DC motor, wherein the drive shaft 16 via a sealed shaft passage in the housing 12 is guided in and coaxial bearing bores interspersed, which from the front sides of the housing parts 13 and 14 as well as from the partition 15 are omitted. At the middle bearing point is the drive shaft 16 directly in the bore of the partition 15 rotatably mounted sliding while the drive shaft 16 at the lateral bearings via a bearing sleeve 17 and a bearing sleeve 17 ' is rotatably mounted plastic gliding. The bearing sleeves 17 and 17 ' are each formed as a hollow cylinder and are positively between the circumference of the drive shaft 16 and the associated bore wall of the housing part 13 respectively. 14 ,

Between the bearings passes through the drive shaft 16 following the bearing sleeve 17 respectively. 17 ' one pressure piece each 18 respectively. 18 ' that is integral with the associated bearing sleeve 17 respectively. 17 ' is formed, then a central insertion opening in the associated pinion 19 respectively. 19 ' the internal gear pumps 11 respectively. 11 ' and finally an associated shaft seal 20 respectively. 20 ' in an associated, stepped extension of the bearing bore for the drive shaft 16 in the partition 15 is pressed.

As in connection with the side view of the pump chamber of the internal gear pump 11 to 2 can be seen, passes through the drive shaft 16 with an approximately hexagonal cross-section, which has gently rounded edges, a matching hollow cross-section of the pinion 19 , whereby a rotationally secure driver connection between the pinion 19 and the drive shaft 16 given is. The external toothing of the pinion 19 meshes with the internal teeth of a ring gear 21 which, in turn, rotatable with the circular outer periphery in a bore portion of the associated housing part 13 is stored. The toothing engagement is located exactly in the middle of the upper portion of the internal toothing of the ring gear 21 , causing the head circles of pinion 19 and ring gear 21 delimiting a generally crescent-shaped annular space. This annular space is related to the vertical median plane of the wheelset, in which the axes of rotation of pinion 19 and ring gear 21 run, designed mirror-symmetrically. In the crescent-shaped annulus is centrally a filler 22 by means of a centrally located axle bolt 23 pivotally mounted. However, the pivoting mobility is limited to a minimum, since the outer peripheral side of the filler 22 with little play on the covered tooth tips of the internal teeth of the ring gear 21 and the inner peripheral side of the filler 22 with little play on the covered tooth tips of the pinion 19 is applied. In the partition 15 is also on the right suction side of the internal gear pump 11 a suction channel 24 and on the left pressure side, an associated pressure channel 25 to recognize the brake fluid.

Will now be with fully filled with brake fluid and vented internal gear pump 11 the drive shaft 16 z. B. rotated by an electric gear motor clockwise, so the pinion rotates 19 synchronous with and also the ring gear 21 becomes the pinion due to the meshing engagement 19 co-rotated in the same direction. Because of the filler 22 Covered tooth gaps on one end face of acted upon by corresponding axial force pressure piece 18 and on the opposite end by running on the partition 15 are sealed, the recorded from the tooth gaps hollow volumes of brake fluid with sufficient Ab seal the tooth heads against the filler 22 with appropriate pressure increase from the suction channel 24 to the pressure channel 25 the internal gear pump 11 be transported. The necessary sealing between tooth tips and filler 22 comes here alone due to a defined circumferential clearance of the filler 22 by which, during operation, a pressure distribution over the circumferential extent of the filler 22 that results in a sufficient rotational force of the filler 22 around the central longitudinal axis of the axle bolt 23 leads. When turning the pinion 19 in clockwise direction thus also results in a rotational force on the filler 22 in a clockwise direction, eliminating the inner peripheral side of the filler 22 from the lever arm on the left of the axle bolt 23 on the covered tooth heads of the pinion 19 and the outer peripheral side of the lever arm to the right of the axle bolt 23 on the tooth tips of the ring gear 21 is depressed. Due to the Verzwängung the lever ends of the filler 22 between the gears of pinion 19 and ring gear 21 results in an opposite same contact pressure of the filler 22 how to adequately seal between the covered tooth tips and the filler 22 is required.

As already explained, the internal gear pump becomes 11 ' from the drive shaft 16 co-driven, as well as the pinion 19 ' from the drive shaft 16 interspersed and over one of the pinion 19 corresponding driver connection rotatably connected thereto. Also the geometry of the internal gear pump 11 ' as such is largely consistent with that of internal gear pump 11 match, where the wheelset from tickling 19 ' and ring gear 21 ' 180 degrees from the sprocket wheel set 19 and ring gear 21 are arranged rotated. Because of this by 180 degrees against each other rotated Radsatzan order in the internal gear pumps 11 and 11 ' , So an opposite eccentric arrangement, the resultant of the compressive forces act on the pressure side of the internal gear pump 11 respectively. 11 ' in opposite radial directions, as in 1 indicated by thick arrows. Thus, these resulting radial forces largely cancel, resulting in a more favorable dimensioning of the pump housing 12 allows, since in the dimensioning of the same essentially only the forces acting through the axial displacement of the resultant moments must be considered constructively.

It is understood that in the counter eccentrically arranged internal gear pumps 11 and 11 ' also the pressure pieces 18 and 18 ' as well as the patches 22 and 22 ' must be arranged rotated 180 degrees against each other. The same applies to the suction channel 24 ' and the pressure channel 25 ' which also in the partition 15 integrated and to the pump chamber of the internal gear pump 11 ' are open.

As in the sectional view through the partition 15 according to 3 can be seen, lie in the pump chamber of the internal gear pump 11 opening suction channel 24 and the associated pressure channel 25 essentially in the same cross-sectional plane as in the pump chamber of the internal gear pump 11 ' opening suction channel 24 ' and the associated pressure channel 25 ' , In addition, they are arranged radially so far in the direction of the outer circumference, that they without impairing the function under axial overlap to the pressed-shaft seals 20 and 20 ' can stand. This requires the dividing wall 15 Overall, only have a slightly greater thickness than that for the integration of the axial and radial channel portion of the suction channel 24 respectively. 24 ' anyway required. In the same cross-sectional area is additionally a leakage channel 26 for removal into the bearing bore of the partition 15 Penetrated brake fluid arranged from the bearing bore of the partition 15 between the shaft seals 20 and 20 ' goes out, diagonally through the partition 15 extends and into the two suction channels 24 and 24 ' opens. It can also be seen that in the suction channels 24 and 24 ' one pressure-reducing valve each 27 respectively. 27 ' and in the pressure channels 25 and 25 ' one overpressure valve each 28 respectively. 28 ' is arranged, wherein the arrangement is made so that all of the partition 15 recorded valves 27 . 27 ' 28 and 28 ' in each switching state within bulkhead cavities.

At the pressure relief valves 28 and 28 ' it is identical, oppositely arranged pressure relief valves of conventional design, in which a ball is in the flow path of the pressure channel and is pressed by the force of a return spring to its sealing seat. As soon as the fluid pressure at the sealing seat is greater than the spring force, the ball is displaced and the flow path of the pressure channel is thus released. The pressure channels 25 and 25 ' with their radial length section diametrically opposite each other near the circumference in the partition wall 15 are integrated, are thus moved radially outwardly at an appropriate pressure against the spring load and thereby fluidly connected to the associated brake circuit or closed again with a corresponding change in the pressure ratios by spring force and thereby fluidly separated from the brake system.

In contrast, the pressure reducing valves 27 and 27 formed as a linear slide valves, which the radial flow path of the suction channel 24 respectively. 24 ' transversely transversely with a tapered control section and are also used in the opposite direction. The sliding instructions of the pressure reducing valves 27 and 27 ' extend to each other and to the radial lengths of the pressure channels 25 and 25 ' parallel. Also the valves of the pressure reducing valves 27 and 27 ' are each held by the spring force of an associated helical compression spring in an axial starting position, but the passage position of the pressure reducing valve 27 respectively. 27 ' equivalent. The helical compression spring is in each case supported on the annular end face of a piston section adjoining the control section, the seal being sealed in its bore of the dividing wall 15 slidably guided, and the control section engages with an end portion having a central bore in an associated blind hole bore of the partition wall 15 one. Now increases the fluid pressure in the suction channel 24 respectively. 24 ' above a predetermined limit value, the fluid which has flowed into the blind hole presses against the annular end face of the control section and thus displaces the piston of the pressure reducing valve 27 respectively. 27 ' against the force of the return spring, wherein the flow path of the suction channel 24 respectively. 24 ' increasingly displaced by the advancing control section and thereby causes a corresponding throttling of the fluid flow. In the present case, the assignment of the internal gear pumps 11 and 11 ' brake circuits of a brake system are the components of the pressure reducing valves 27 and 27 ' coordinated so that a pressure limit of about 10 bar on the suction side of the internal gear pumps 11 respectively. 11 ' can not be exceeded. This can cause unnecessary frictional forces in the internal gear pumps 11 and 11 ' be avoided, both in terms of the efficiency of the pump assembly 10 as well as in terms of their wear would adversely affect. If fluid gets out of the suction channel 24 respectively. 24 ' at the sealing level of the pressure reducing valve 27 respectively. 27 ' the same in the guide bore, so it can together with fluid from the leakage channel 26 drain as the Guide bore to the periphery of the partition 15 is open and thus additionally serves as a drain opening.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 10053991 A1 [0002]

Claims (10)

Pump assembly ( 10 ) for the synchronous pressurization of two fluid circuits, the two together in a pump housing ( 12 ), via its drive shaft ( 16 ) Rotary driven internal gear pumps ( 11 . 11 ' ) whose pinion ( 19 . 19 ' ) lie in the associated pump chamber and in meshing engagement with its ring gear ( 21 . 21 ' ), wherein the pump chambers of the internal gear pumps ( 11 . 11 ' ) by a common partition ( 15 ) are separated from each other, which is formed as a separate housing part and in a hollow cross-section of a peripheral wall of one of the internal gear pumps ( 11 . 11 ' ) forming housing part ( 13 ) and wherein the internal gear pumps ( 11 . 11 ' ) associated suction channels ( 24 . 24 ' ) and pressure channels ( 25 . 25 ' ) after an axial length in the lateral boundary wall of the associated pump chamber into a radially in the pump housing ( 12 ) extending longitudinal section, characterized in that the suction channel ( 24 . 24 ' ) and the pressure channel ( 25 . 25 ' ) one of the internal gear pumps ( 11 . 11 ' ) in the partition ( 15 ) are integrated. Pump assembly according to claim 1, characterized in that the suction channels ( 24 . 24 ' ) and the pressure channels ( 25 . 25 ' ) of both internal gear pumps ( 11 . 11 ' ) in the partition ( 15 ) are integrated. Pump assembly according to claim 1 or 2, characterized in that in the partition wall ( 15 ) a leakage channel ( 26 ) is integrated, which with a drain opening of a suction channel ( 24 . 24 ' ) in the partition ( 15 ) is fluidly connected. Pump assembly according to claim 1 or 2, characterized in that each suction channel ( 24 . 24 ' ) and each pressure channel ( 25 . 25 ' ) of the partition ( 15 ) are arranged in the same cross-sectional area of the same. Pump assembly according to claim 1 or 2, characterized in that in at least one suction channel ( 24 . 24 ' ) or pressure channel ( 25 . 25 ' ) of the partition ( 15 ) A valve arrangement is provided. Pump assembly according to claim 5, characterized in that in each suction channel ( 24 . 24 ' ) of the partition ( 15 ) a pressure reducing valve ( 27 . 27 ' ) and in each pressure channel ( 25 . 25 ' ) of the partition ( 15 ) a pressure relief valve ( 28 . 28 ' ) are arranged. Pump assembly according to claim 1, characterized in that the partition ( 15 ) is a cylindrical disc with plane-parallel end faces, which in a cylindrical hollow cross-section of the associated housing part ( 13 ) is pressed. Pump assembly according to claim 7, characterized in that the pressed partition ( 15 ) axially on an annular end face of the housing part ( 13 ) and on its opposite end face an annular end face of the subsequent housing part ( 12 ) are supported, wherein the tubular end portions of the housing parts ( 13 . 12 ) are joined under telescopic length coverage. Pump assembly according to claim 1, characterized in that the wheelsets of the internal gear pumps ( 11 . 11 ' ) on their ends of the pump assembly ( 10 ) facing end faces of an associated pressure piece ( 18 . 18 ' ) are axially loaded, the one bearing sleeve ( 17 . 17 ' ) for the drive shaft ( 16 ). Pump assembly according to claim 9, characterized in that the pressure piece ( 18 . 18 ' ) and the bearing sleeve ( 17 . 17 ' ) consist of plastic and are formed in one piece.