JP2014031792A - Internal gear pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve conventional internal gear pumps.SOLUTION: The present invention relates to an internal gear pump (1) comprising an axial disk (18) in contact with both gears (2, 3). To seal a pressurized region (22) thereof, the present invention presents a packing device comprising: a packing ring (25) having an L-shaped ring cross section and disposed in an outline part of the pressurized region (22); and an O ring (26) disposed inside an inner hollow surface of the packing ring (25).

Description

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

  The internal gear pump has an internal gear called an internal gear and an external gear called a pinion that meshes with the internal gear. In the crescent-shaped pump chamber located between these gears, a separating member for separating the suction region in the pump chamber from the pressurizing region is disposed. The suction area communicates with the pump suction section, and the pressurization area communicates with the pump discharge section. The separation member is often called a sickle-like member or a crescent-like member because of its typical shape, but is also called a filling member. The tooth head of the pinion abuts on the inside of the separating member, and the outside tooth head of the tooth of the internal gear abuts on the outside. When the internal gear pump is operated, the tooth head is separated when the gears are driven to rotate. Slide along the inside and outside of the member. The separating member is a liquid in the hydraulic vehicle brake device that is transported from the suction area of the pump chamber to the pressurizing area along the inside and outside of the separating member during rotation of the gear during operation. , Contain in the middle tooth space.

  In order to perform sealing in the axial direction, an axial disk that is in contact with an end face of a gear of an internal gear pump and an end face of a separating member and is comparable to an axial slide bearing is known. An axial disk, also called a control plate or a pressure plate, is non-rotatable and movable in the axial direction. The axial disk is an outer surface on the side opposite to the gear of the internal gear pump, and is usually subjected to the action of pressure from the pressurizing region or the pump discharge portion, and is thereby pressed against the end surfaces of the gear and the separating member. As described above, this pressing can be compared with an axial slide bearing, and the gear can rotate even though the axial disk is pressed on the side. The conveyed brake fluid reaches between the axial disk and the gear and forms a lubricating film that facilitates sliding. A complete seal of the pump chamber is not necessary and leakage is acceptable. However, efforts should be made to obtain an appropriate compromise between low friction, wear, and excellent sealing of the brake fluid conveyed in the intermediate space of the internal gear pump gear.

  The axial disk has a so-called pressurizing region on the outer surface on the side opposite to the gear and the separating member due to the action of pressure. The pressurizing zone is a shallow concave portion provided on the outer surface of the axial disk and extends substantially over the pressurizing zone of the pump chamber, and typically has a crescent or semi-crescent shape. The pressurization zone is in communication with the pump discharge and / or the pressurization zone for the action of pressure.

  Patent Document 1 discloses an example of such an internal gear pump. However, in this document, the pressurizing zone is not provided on the outer surface of the axial disk, but the inner surface of the axial casing side of the pump casing end wall of the internal gear pump (the axial disk between this inner surface and the gear pump). Is provided). The pressurizing region of this known internal gear pump has a groove in which an O-ring as a packing for sealing the pressurizing region is enclosed along the contour of the pressurizing region.

German patent 1961833B4 specification

  The present invention is an improvement over conventional internal gear pumps.

  The internal gear pump according to the present invention having the configuration of claim 1 includes a packing device including a packing ring and an elastic ring for sealing one pressurizing region or a plurality of pressurizing regions. Yes. The packing ring has an L-shaped ring cross section and a shape that at least substantially corresponds to the contour of the pressurizing region in an undeformed state. One leg of the L-ring cross-section is axially parallel to or substantially parallel to the internal gear pump and is directed towards the bottom of the pressurizing zone. The other leg of the L-shaped ring cross section is on the outer surface of the axial disk and is used to seal the pressure zone, for example the inner surface of the end wall of the pump casing The axial disk is placed on the

  The elastic ring is disposed on the hollow inner surface of the L-ring cross section of the packing ring, and is circular when not deformed. The elastic ring is arranged in the L-shaped cross section of the packing ring to obtain the shape of the contour of the pressurizing zone. Thereby, a commercially available circular packing ring, for example, an O-ring, can be used as the elastic ring of the packing apparatus according to the present invention, and can be obtained at low cost as a mass-produced part. The elastic ring presses against and abuts the sealing leg of the L-ring cross section of the packing ring by the pre-tensioning force when the elastic ring is attached and / or by the action of pressure in the pressure zone. And seal. The elastic ring has a pre-tensioning force because its diameter or its axial height is greater than the free space provided to the elastic ring. As a result, the elastic ring is elastically compressed during installation. The action of the pressure in the pressure zone causes the elastic ring to be radially compressed with respect to the internal gear pump, so that the elastic ring causes the sealing leg of the packing ring to e.g. against the inner surface of the end wall of the pump casing of the internal gear pump. Press, abut and seal.

  The dependent claims are directed to advantageous configurations and other configurations of the invention according to claim 1.

  An advantage of the present invention is the simple configuration of the packing device, in particular the small size of the packing device as in the case of an internal gear pump used as a hydro pump in a hydraulic vehicle brake device. There is little risk of mounting errors and damage to the packing device. The packing device only requires one special part, i.e. only a packing ring.

  Next, the present invention will be described in detail with respect to the embodiments shown in the drawings.

1 is a diagram of an internal gear pump according to the present invention. FIG. 2 is a perspective view of an axial disk of the internal gear pump of FIG. 1 according to the present invention. FIG. 3 is an axial sectional view of the axial disk of FIG. 2.

  The internal gear pump 1 according to the present invention shown in FIG. 1 has an internal gear 2 and a pinion meshing with the internal gear 2, and the pinion is disposed on the pump shaft 4 so as not to be relatively rotatable. . The pinion 3 is an external gear, the internal gear 2 is an internal gear, and the pinion 3 and the internal gear 2 can also be called gears of the internal gear pump 1. The internal gear 2 is slidably supported by a support ring 5 so as to be rotatable. The pump casing is not shown.

  The internal gear 2 and the pinion 3 define a crescent-shaped pump chamber 6 between them, and the pump chamber 6 is divided into a suction region 8 and a pressurizing region 9 in the pump chamber. The half crescent-shaped separation member 7 is disposed. A suction hole 10 opens in the suction area 8, and a discharge hole 11 protrudes from the pressurization area 9. The separating member 7 is divided into a plurality of parts, and an inner part 12 and an outer part 13 which are pivotally connected to each other, and a leg spring 15 which is arranged in an intermediate space 14 between the inner part 12 and the outer part 13. And a packing 16 disposed in an intermediate space 14 between the inner portion 12 and the outer portion 13 in the same manner. The separating member 7 is supported by a support 17 on the suction side, and the support is formed as a pin penetrating the pump chamber 6 in the lateral direction in this embodiment. The intermediate space 14 between the inner part 12 and the outer part 13 of the separating member 7 communicates with the pressure area 9, so that the inner part 12 and the outer part 13 dominate within the leg spring 15 and the pressure area 9. The inner portion 12 is pressed inward against the tooth head of the pinion 3 and the outer portion 13 is pressed outward against the tooth head of the internal gear 2. The separating member 7 contains a liquid amount in an intermediate space between the teeth of the internal gear 2 and the teeth of the pinion 3, and as a result, when the internal gear pump 1 is operated and the gears 2 and 3 are rotationally driven. The liquid is transported from the suction area 8 to the pressure area 9. This is known per se and will not be described in detail here. For the configuration and function of the internal gear pump, refer to Patent Document 1 mentioned at the beginning.

  In order to seal the sides of the pump chamber 6, the internal gear pump 1 has an axial disk 18 which abuts against the end faces of the gears 2, 3 and the separating member 7. The axial disk 18 is held so as to be movable in the axial direction but not relatively rotatable. The contact of the axial disc 18 with the gears 2 and 3 is comparable to that of an axial slide bearing, and the gears 2 and 3 can rotate despite the axial disk 18 being pressed to the side. The liquid (brake liquid in this embodiment) conveyed by the contact gear pump 1 forms a lubricating film between the gears 2 and 3 and the axial disk 18.

  The axial disk 18 may be a disk that covers the entire internal gear 2 from the side. In this embodiment, the axial disk 18 does not extend over 360 ° but extends over 180 °. The axial disk has the shape of a circular slice, occupies more than half of one circle, and has a stepped withdrawal portion at one end of the chord portion defining the circular slice (FIG. 2). The axial disk 18 has a pump shaft 4, a support 17, and through holes 19, 20, 21 for the pump discharge part 11. One axial disk of the two axial disks 18 is shown in FIG. 2 and the side that is visible in this case is on the side opposite to the gears 2, 3 and the separating member 7, and the pump casing (not shown) This is the outer surface of the axial disk 18 on the inner surface side of the end wall. The axial disk 18 has a pressurizing area 22 on the outer surface, and this pressurizing area is a flat semi-crescent shaped counterbore, between the outer periphery of the axial disk 18 and the through hole 19 for the pump shaft 4. It extends over less than about 180 ° and covers the pressurizing region 9 and the separating member 7 almost to the vicinity of the suction region side end of the separating member. The penetrating part 21 of the pump discharge part 11 opens into the pressurization area 22, and as a result, the pressurization area 22 communicates with the pressurization area 9 and the pump discharge part 11, that is, the pressurization area 22 includes The pressure of the discharge part 11 dominates.

  The pressurizing zone 22 has a counterbore 23 extending along the contour of the pressurizing zone 22 at the bottom thereof. The counterbore 23 is provided with a groove 24 (FIG. 3) which is deepened at its outer edge along the contour of the pressure zone 22. A packing device is disposed in the spot facing portion 23, and the packing device includes a packing ring 25 having an L-shaped ring cross section and an elastic ring 26. Since the ring cross-section of the packing ring 25 is L-shaped, it is also simply referred to as an L-shaped ring below. The packing ring 25 is made of, for example, a thermoplastic material such as polyamide or PPS (polyphenylene sulfide), and has a half crescent shape that is an outline of the pressure region 22 in an undeformed state. Since the ring cross-section of the packing ring 25 is L-shaped, it has two legs. In the following, one leg is referred to as a fixed leg 27 and the other leg is referred to as a sealing leg 28. To. The fixed leg 27 is parallel to the axis of the internal gear pump 1, protrudes into the groove 24 at the contour of the pressurizing zone 22, and is inscribed in the wall 29 surrounding the pressurizing zone 22. The fixed leg 27 has a compression element 30 that holds a clamped state in the groove 24 and protrudes laterally in the groove 24. The compression element is a warp-like projection or a nose-like projection protruding to the side, and extends in the circumferential direction of the packing ring 25 and may be formed continuously in the circumferential direction, or includes an interruption portion. Each piece may extend with a width.

  The sealing leg 28 is substantially located at the height of the outer surface of the axial disk 18 on the side opposite to the gears 2, 3 and the separating member 7, and is inclined at an acute angle, so that the sealing leg 28 is free The end protrudes from the outer surface of the axial disk 18. The degree of protrusion of the sealing leg 28 is indicated by the alternate long and short dash line 31 at the height of the outer surface of the axial disk 18 in FIG. The sealing leg portion 28 of the packing ring 25 abuts against the inner wall (not shown) of the pump casing of the internal gear pump 1 like a kind of packing collar to perform a sealing function. The pressure zone 22 of the axial disk 18 which is subjected to the action of the dominant pressure is sealed.

  The elastic ring 26 is a conventional O-ring, is circular without being deformed, and has a hollow surface or an inner surface of an L-shaped ring cross section of the packing ring 25 and a counterbore portion 23 provided in the contour portion of the pressurizing region 22. It is hold | maintained by the shape of the outline part of the pressurization area 22 by arrange | positioning. Its diameter is greater than the clearance between the sealing leg 28 of the packing ring 25 and the bottom of the recess 23, so that the elastic ring 26, by virtue of its elasticity, makes the sealing leg 28 an end wall (not shown) of the pump casing. To seal the inner surface. The pressure action in the pressurizing zone 22 causes the elastic ring 26 to compress in the radial direction relative to the pump, so that its pressure increases in a direction parallel to the axis, so that the sealing leg 28 of the packing ring More strongly press against the inner surface of the end wall of the pump casing. Therefore, the pressure increase in the pressurizing zone 22 improves the sealing action of the packing device. The sealing leg portion 28 is in contact with the surface to be sealed, and can be compared with a packing collar pressed against the surface when pressure is applied.

  According to the present invention, the internal gear pump 1 is provided as a hydropump of a hydraulic vehicle brake device, a slip control type vehicle brake device, and / or a vehicle power brake device (not shown), and brake lock protection control, traction Used for slip control, such as slip control and / or dynamic drive control, and / or for generating brake pressure in a vehicle hydraulic power brake system. Such a hydropump is usually a piston pump today, and is not necessarily an accurate expression, but is also called a reverse pump. Abbreviations such as ABS, ASR, FDR, and ESP are used for the slip control, and the dynamic drive control is generally called stability control.

DESCRIPTION OF SYMBOLS 1 Internal gear pump 2 Internal gear 3 Pinion 6 Pump chamber 18 Axial disk 22 Pressurization area 25 Packing ring 26 O-ring (elastic ring)

Claims (9)

  In order to define the side of the pump chamber (6), the internal gear (2) and the pinion (3) of the internal gear pump (1) abut against the end faces of the internal gear (2) and the pinion (3). An axial disk (18) having a pressurizing zone (22) on the outer surface opposite to the side, and the pressurizing zone is sealed by a packing ring (25) surrounding the pressurizing zone (22) In the internal gear pump, the internal gear pump (1) has a packing device, and the packing device has a contour shape of the pressurizing zone (22) and an L-shaped ring cross section. An internal gear pump comprising a packing ring (25) and an elastic ring (26) enclosed inside the L-shaped ring cross section of the packing ring (25).   The internal gear pump according to claim 1, characterized in that the elastic ring (26) is circular when not enclosed in the packing ring (25).   Internal gear pump according to claim 1 or 2, characterized in that the elastic ring (26) is an O-ring.   Internal gear pump according to any one of claims 1 to 3, characterized in that the inner surface of the L-shaped ring cross section of the packing ring (25) faces the axial disk (18). .   The L of the packing ring (25) provided on the outer surface of the axial disk (18) opposite to the internal gear (2) and the pinion (3) of the internal gear pump (1). A sealing leg (28) with a cross-section of the shaped ring extends at an acute angle with respect to the outer surface of the axial disk (18) and protrudes from the outer surface of the axial disk (18) in an undeformed state; 5. The internal gear pump according to claim 1, wherein the internal gear pump is characterized by the following.   A fixed leg (27) parallel to the internal gear pump (1) of the L-shaped ring cross section of the packing ring (25) protrudes from the elastic ring (26). An internal gear pump according to any one of claims 1 to 5.   The fixed leg portion (27) of the L-shaped cross section of the packing ring (25) is clamped in a groove (24) provided at the bottom of the pressurizing zone (22) in the axial disk (18). The internal gear pump according to claim 6, wherein the internal gear pump is held.   The fixed leg (27) of the L-shaped ring cross-section of the packing ring (25) has a compression element (30) protruding sideways, together with the thickness of the fixed leg (27), The compression element is larger than the width of the groove (24) provided at the bottom of the pressure zone (22) in the axial disk (18) and holding the fixed leg (27). The internal gear pump according to claim 7, wherein the internal gear pump is characterized.   The internal gear pump according to any one or more of the preceding claims, characterized in that the internal gear pump (1) is a hydropump of a hydraulic vehicle brake device.

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