JP2014526648A - Internal gear pump - Google Patents

Abstract

The present invention relates to an internal gear pump as a reverse pump of a hydraulic vehicle brake device having traction control. In the present invention, the ring gear (4) of the internal gear pump (1) is placed in a support ring (5) made of plastic having a pressure pocket (12) on the discharge side P of the internal gear pump (1). It is proposed that the pressure pocket (12) is subjected to the action of the outlet pressure of the internal gear pump (1). The present invention causes the ring gear (4) to cancel out the radial force.
[Selection] Figure 1

Description

  The present invention relates to an internal gear pump having the structure of the preamble of claim 1.

  Patent document 1 is disclosing the internal gear pump provided with the internal gear ring gear and the pinion. The pinion is eccentrically arranged in the ring gear and meshes with the ring gear at the peripheral portion. As a result, the ring gear is also rotated by the rotational drive of the pinion, and the internal gear pump conveys the hydraulic fluid in a known manner. The ring gear is rotatably supported in the pump case. The ring gear is an internal gear, and the pinion is an external gear. This external gear is referred to as a pinion here to distinguish it from a ring gear. A ring gear and a pinion can also be called the gear of an internal gear pump. A crescent-shaped hollow space (herein referred to as a pump chamber) is provided between the ring gear and the pinion on the outer side of the peripheral portion where both gears of the internal gear pump mesh with each other. A separation member is disposed in the pump chamber. This separating member is also called a crescent or crescent because of its shape. The tooth head of the ring gear abuts against the outer surface of the separating member, and the tooth head of the pinion abuts against the inner surface of the separating member, so that the working fluid is confined in the tooth hollow space of these gears, and the internal gear pump When the gear is driven to rotate, it is conveyed from the suction side to the discharge side. The separation member divides the pump chamber into a suction region and a discharge region, the suction region communicates with the pump inlet, and the discharge region communicates with the pump outlet.

German patent 1961833B4 specification

  The internal gear pump according to the present invention having the structure of claim 1 has a support ring, the support ring is disposed in the pump case so as not to be relatively rotatable, and the ring gear is rotatably supported in the support ring. Yes. The support ring allows a material for rotatably supporting the ring gear, which is different from the pump case material, for example allowing a more wear-resistant material and / or less friction material, or a material for the support ring It also makes it possible to produce pump cases from less expensive materials.

  The support ring of the internal gear pump according to the present invention has a pressurizing pocket subjected to the action of pressure in the pressurizing region of the pump chamber, and the pressurizing pocket opens inward with respect to the ring gear. The pressurizing pocket is a hollow space or a kind of recess and does not need to be deeply formed in the radial direction, and may be flat. Due to the pressure, the ring gear is subjected to pressure from the outside in the pressurizing region of the pump chamber. Thereby, the action of the pressure on the ring gear from the inside in the pressurizing region of the pump chamber is ideally canceled or at least partially cancelled. The radial force produced by the action of the pressure from the inside is completely or at least partly canceled out and in some cases is over canceled, so that the radial force acting on the ring gear is zero or at least small or at least reduced. The degree of cancellation is the pressure in the pressure pocket expressed by the ratio of the peripheral area of the ring gear that applies pressure to the pressure pocket of the support ring and the area that acts on the ring gear from the inside and the area that acts from the inside. Depends on the strength of the action. By providing a pressure pocket in the support ring, the internal gear pump according to the invention has a complete or partial radial offset of the ring gear.

  The present invention was originally made for an internal gear pump that has a separating member in the pump chamber and is called a crescent pump because the separating member has a substantially crescent shape. However, the present invention is also applicable to a so-called annular gear pump that does not have a separation member in the pump chamber.

  The dependent claims are directed to advantageous configurations and further configurations of the invention as defined in claim 1.

  According to claim 2, the pressurization pocket communicates with the pressurization region of the pump chamber and / or the pump outlet, in which case the pressurization region communicates with the pump outlet and as a result of the flow of hydraulic fluid by the internal gear pump. If pressure loss is exaggerated, the same pressure will dominate both. In this configuration of the invention, the pressure action on the ring gear from the outside in the pressurization pocket is adapted to the pressure action from the inside in the pressurization area of the pump chamber, so that the radial offset is within the pressurization area of the pump chamber. And has the advantage of having little to do with pressure changes in the pump outlet.

  According to the structure of the present invention, the support ring is made of plastic (Claim 3), for example, polytetrafluoroethylene (PTFE; Claim 4). Polytetrafluoroethylene has excellent sliding bearing characteristics with low frictional resistance and high wear stability. A further advantage of plastics, in particular polytetrafluoroethylene, is the axial calibration of the support ring by precisely matching the gear of the internal gear pump and, if provided, the width of the separating member.

  According to the further structure of this invention, the packing lip which contact | abuts the outer surface of a ring gear is provided in the peripheral end of the sealing pocket (Claim 5). Preferably, such packing lips are provided at both peripheral ends of the sealing pocket. The elasticity of the support ring, especially when it is made of plastic, makes it possible to form such a packing lip.

  For sealing purposes, according to claim 6, the outer surface of the packing lip is subjected to the prevailing pressure action in the pressure pocket. As a result, the packing lip is relatively strongly pressed against the outer surface of the ring gear at a relatively high pressure, and thus the sealing lip is suitably sealed at a high pressure as in the case of a low pressure.

  According to claim 7, the sealing pocket is open at the side. Sealing at the boundary end wall of the pump case or sealing at the so-called thrust disk, which defines the pump chamber and the sealing pocket at the side, is a packing under the influence of the dominant pressure in the sealing pocket. To do. The prevailing pressure acting on the packing in the sealing pocket compresses the packing radially, which causes the packing to stretch laterally. This means that as the pressure rises, the packing comes into stronger contact with the end wall of the pump case or the thrust disk, and as a result, the sealing action when the pressure rises is improved. This achieves a suitable seal at low pressure as in the case of high pressure.

  According to claim 8, the packing of the sealing pocket is made of an elastomer. Elastomers are particularly suitable for side sealing of the sealing pockets due to their material properties, especially when the pressure varies.

  In particular, the internal gear pump according to the invention is provided as a hydropump of a hydraulic vehicle brake device, for example as a so-called reverse pump of a hydraulic vehicle brake device with traction control and / or pressure of a hydraulic vehicle power brake device. Provided for generation. This is the subject of claim 9. Since the brake fluid has poorer lubrication characteristics than the hydraulic fluid, when the internal gear pump according to the present invention is used in a hydraulic vehicle brake device, the ring gear is not supported directly in the pump case but by a unique support ring. It is particularly advantageous to support the rotation. In addition, for small size (the gear of the internal gear pump according to the present invention has a width of approximately 2 to 3 mm as a hydropump of a hydraulic vehicle brake device), there is a special demand for manufacturing accuracy, in particular. This can be more preferably solved by using the configuration according to the present invention than when the ring gear is directly supported in the pump case.

  The pump case of the internal gear pump according to the invention may be a so-called hydraulic block or may be a region of such a hydraulic block of a hydraulic vehicle brake device (claim 8). Such hydraulic blocks are known from hydraulic vehicle brake devices with traction control. Within the hydraulic block, in addition to one or more hydro pumps (ie internal gear pumps here) or for each brake circuit of such internal gear pumps, solenoid valves, hydro accumulators, and Other hydraulic components of the traction control are incorporated and are hydraulically connected to each other. An electric motor as a pump motor for driving an internal gear pump is usually flange-coupled to a hydraulic block.

  The present invention will now be described in detail with respect to an embodiment illustrated in the drawings.

It is a side view of the internal gear pump by this invention.

  The internal gear pump 1 according to the present invention shown in the drawings is provided as a hydro pump or a so-called reverse feed pump in a hydraulic vehicle brake device having a traction control. The pinion 2 is arranged eccentrically in an internal gear ring gear 4 that is rotatably received in the support ring 5. The pinion 2 meshes with the ring gear 4 at the circumferential portion. The ring gear 4 is rotationally driven together by the rotational drive of the pinion 2 by the pump shaft 3, so that the internal gear pump 1 delivers fluid in a manner known per se, the illustrated embodiment of the internal gear pump 1 according to the invention. Then, the brake fluid is conveyed. The pinion 2 and the ring gear 4 are also referred to as gears 2 and 4 of the internal gear pump 1. The internal gear pump 1 has a crescent-shaped pump chamber 6 between the pinion 2 and the ring gear 4 so as to face the peripheral portion where the gears 2 and 4 mesh with each other. In the regions at both ends of the pump chamber 6, holes are opened in the pump chamber 6 in parallel with the pump shaft 3. One of these two holes forms a pump inlet 7 and the other hole forms a pump outlet 8. The pump inlet 7 can be regarded as the suction side of the internal gear pump 1 and the pump outlet 8 can be regarded as the discharge side.

  A separation member 9 is disposed in the pump chamber 6 between the pump inlet 7 and the pump outlet 8, and the separation member is also called a crescent body or a crescent member because of its shape. The separating member 9 separates the suction inlet side S of the pump chamber 6 from the pressurized outlet side P. The outer surface of the separating member 9 is in contact with the tooth head of the tooth of the ring gear 4, and the inner surface of the separating member 9 is in contact with the tooth head of the tooth of the pinion 2. The separation member 9 is supported by a pin on the suction side S, and the pin penetrates the pump chamber 6 parallel to the pump shaft 3 on the suction side S of the separation member 9 to form an opposing support member 16 for the separation member 9. doing.

  The support ring 5 is disposed in the pump case 10 so as not to be relatively rotatable. The support ring has a pinion 2, i.e. an external gear arranged on the pump shaft 3 so as not to rotate relative to it. The case cover is not shown in order to make the internal member of the internal gear pump 1 visible. The side of the pump chamber 6 is defined by an axial plate 11, which is in contact with the end faces of the gears 2, 4 of the separating member 9 and the end face of the support ring 5. The pump shaft 3 and the opposing support member 16 pass through the axial plate 11, whereby the axial plate is held so as not to be relatively rotatable. The axial plate 11 is movable in the axial direction, and its outer surface on the side opposite to the gears 2 and 4 is subjected to the dominant pressure in the pump outlet 8, whereby the end surfaces of the gears 2 and 4 and the separating member are separated. It is pressed against the end face of 9 and abuts in a sealed state. The axial plate 11 covers the discharge side P and the separating member 9, and reaches a part of the suction side S that is partially covered by the axial plate 11. For the pump outlet, at least one of the two axial plates 11 has a hole congruent with the pump outlet 8. The pump inlet 7 is outside the axial plate 11.

  The support ring 5 has a pressurization pocket 12 in the region on the discharge side P of the pump chamber 6, and the pressurization pocket meshes with the gears 2 and 4 from the central region of the separation member 9 in the circumferential direction. It extends to the vicinity of the area. The pressurizing pocket 12 is a drawing portion opened on the inner surface of the support ring 5. Among them, the pressure from the pump outlet 8 or the discharge side P of the pump chamber 6 is dominant. In the illustrated embodiment, the pressure pocket 12 in the support ring 5 communicates with the discharge side P through a notch 13 provided on the inner surface of the axial plate 11 on the gears 2 and 4 side. The notch 13 is T-shaped, and its shaft portion extends from the discharge side P to the outside in the radial direction to the pressure pocket 12, where the shaft tip portion of the notch 13 partially extends in the circumferential direction. ing. This shape of the notch 13 is not compulsory for the present invention, it is important that the pressurization pocket 12 communicates with the pressure on the discharge side P or the pump outlet 8, which is basically an axial. You may implement | achieve in the aspect different from the aspect which provided the notch 13 in the inner surface of the plate 11. FIG.

  The outer surface of the ring gear 4 is subjected to the action of the same pressure as the pressure that the ring gear 4 acts on the discharge side P from the inside in the region of the pressure pocket 12. This is performed regardless of the magnitude of the pressure on the discharge side P, that is, even if the pressure in the pump outlet 8 changes. The pressurizing pocket 12 under the action of the pressure on the discharge side P provides a complete or partial or excessive cancellation of the radial force caused by the pressure on the inner surface of the ring gear 4. The amount of thrust force cancellation depends on how much the pressurizing pocket 12 extends in the circumferential direction. If the pressure pocket 12 is relatively long, the radial force directed inward is exerted on the ring gear 4, and if the pressure pocket 12 is relatively short in the circumferential direction, the radial force directed outward is exerted on the ring gear 4. Normally, the effort is made to obtain a pressure pocket 12 that counteracts the radial force, so that the ring gear 4 is not subjected to a radial force, or the support ring 5 that faces the pressure gear 12 against the ring gear 4. A slight over-compensation is performed such that the surface is pressed with a slight force.

  The pressure pocket 12 is open at the side. Sealing with respect to the axial plate 11 is performed by using a striped packing 14, which is arranged at the bottom of the pressure pocket 12, that is, on the outer surface. The packing 14 is subjected to the action of the dominant pressure in the pressure pocket 12, that is, the action of the outlet pressure of the internal gear pump 1. This pressure action causes the packing 14 to compress radially, which causes the packing to extend laterally. As a result, when the outlet pressure increases, the packing 14 is strongly pressed against the axial plate 11 laterally outward, and the packing seals well even when the outlet pressure is high. The packing 14 is made of an elastomer and is suitable for sealing the side of the pressure pocket 12 due to its characteristics.

  The support ring 5 is made of plastic, and due to its elasticity, the packing lip 15 can be formed at the peripheral end of the pressure pocket 12. The packing lip 15 comes into contact with the ring gear 4 from the outside, and the pressure prevailing in the pressurizing pocket 12 acts on the outer surface thereof, that is, the outlet pressure of the internal gear pump 1 acts. This achieves a good sealing of the pressure pocket 12 at its peripheral edge. In the present embodiment, the support ring is made of polytetrafluoroethylene (PTFE), and the polytetrafluoroethylene has good sliding properties, low wear, and is suitable for the packing lip 15.

  The internal gear pump 1 is a hydropump of a hydraulic vehicle brake device (not shown), and is provided as a so-called reverse pump for traction control and / or pressure generation in a hydraulic vehicle power brake device. The pump case 10 is formed by a hydraulic block of a vehicle brake device, and a part of the hydraulic block surrounding the internal gear pump is shown in the drawing. Other hydraulic components such as a solenoid valve, a buffer chamber, and a hydro accumulator are arranged in the hydraulic block and are hydraulically connected to each other. Such hydraulic blocks are known for hydraulic vehicle brake systems with traction control and need not be described in further detail here.

DESCRIPTION OF SYMBOLS 1 Internal gear pump 2 Pinion 4 Ring gear 5 Support ring 6 Pump chamber 7 Pump inlet 8 Pump outlet 10 Pump case 12 Pressure pocket 14 Packing 15 Packing lip P Discharge side S Suction side

The pump case of the internal gear pump according to the invention may be a so-called hydraulic block or may be a region of such a hydraulic block of a hydraulic vehicle brake device (claim 10 ). Such hydraulic blocks are known from hydraulic vehicle brake devices with traction control. Within the hydraulic block, in addition to one or more hydro pumps (ie internal gear pumps here) or for each brake circuit of such internal gear pumps, solenoid valves, hydro accumulators, and Other hydraulic components of the traction control are incorporated and are hydraulically connected to each other. An electric motor as a pump motor for driving an internal gear pump is usually flange-coupled to a hydraulic block.

Claims (10)

  A pump case (10), an internal ring gear (4), an externally arranged pinion (2) that is eccentrically disposed in the ring gear (4) and meshes with the ring gear (4) at a peripheral portion; Between the ring gear (4) and the pinion (2), the pinion (2) is disposed outside the peripheral portion meshing with the ring gear (4) and communicates with the pump inlet (7). An internal gear pump comprising a pump chamber (6) in which a suction side (S) communicates with a discharge side (P) connected to a pump outlet (8). The internal gear pump (1) Has a support ring (5) disposed in the pump case (10) so as not to rotate relative to the pump case (10), and the ring gear (4) is disposed so as not to rotate relative to the support ring. (5) There is a pressure pocket (12) that receives the action of pressure in the region on the discharge side (P) of the pump chamber (6), and the pressure pocket is opened inward to the ring gear (4). An internal gear pump characterized by   2. Internal gear pump according to claim 1, characterized in that the pressure pocket (12) communicates with the discharge side (P) and / or the pump outlet (8).   2. Internal gear pump according to claim 1, characterized in that the support ring (5) is made of plastic.   The internal gear pump according to claim 3, wherein the support ring is made of polytetrafluoroethylene.   The said support ring (5) has the packing lip (15) contact | abutted to the outer surface of the said ring gear (4) in the surrounding end of the said pressurization pocket (12), The claim 1 characterized by the above-mentioned. The internal gear pump described.   6. Internal gear pump according to claim 5, characterized in that the outer surface of the packing lip (15) is subjected to the action of a dominant pressure in the pressure pocket (12).   The pressure pocket (12) is open at the side and has a packing (14), which seals the pressure pocket (12) from the side and the pressure pocket (12). The internal gear pump according to claim 1, wherein the internal gear pump is subjected to an action of pressure dominant in the internal gear pump.   The internal gear pump according to claim 7, characterized in that the packing (14) of the pressure pocket (12) is made of an elastomer.   The internal gear pump according to claim 1, characterized in that the internal gear pump (1) is a hydropump of a hydraulic vehicle brake device.   2. Internal gear pump according to claim 1, characterized in that the pump case (10) is formed by a hydraulic block of a hydraulic vehicle brake device.

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