JP6420050B2 - Internal gear pump - Google Patents

Description

  The present invention relates to an internal gear pump for a hydraulic vehicle brake device having the structure described in the preamble of claim 1. Such an internal gear pump is used in place of the piston pump normally used in slip-controlled and / or power-type vehicle brake devices, and is not necessarily suitable, but is sometimes called a reverse pump.

  An internal gear pump is known and includes an internal gear and a pinion that is eccentrically disposed in the internal gear, and the pinion meshes with the internal gear at a peripheral portion. The internal gear is an internal gear, the pinion is an external gear, and the internal gear and the pinion can be regarded as gears of the internal gear pump. The names pinion and internal gear are used to distinguish them. A crescent-shaped free space (herein referred to as a pump chamber) located between the internal gear and the pinion is opposed to the peripheral portion where these gears are engaged. A partition member is disposed in the pump chamber, and the partition member abuts against the tooth tips of both gears from the outside and the inside to divide the pump chamber into a suction chamber and a pressurizing chamber. The partition member is sometimes called a crescent or crescent member because of its typical shape. Another name of the partition member is a filling member. The gear conveys fluid from the suction chamber to the pressurizing chamber by rotational driving. An internal gear pump without a partition member is also known and is called an annular gear pump for distinction.

  Patent Document 1 discloses an internal gear pump in which a pinion is fixed on a pump shaft provided for rotationally driving a pinion and for rotationally driving an internal gear meshed with the pinion via the pinion. doing. The pump shaft is rotatably supported by sliding bearings press-fitted into the pump case on both sides of the pinion.

German Patent Application Publication No. 4322239A1

  An internal gear pump having the configuration of claim 1 includes an internal gear, a pinion meshing with the internal gear, and a pump shaft for rotationally driving the pinion and the internal gear. Have. According to the present invention, the bearing for rotationally supporting the pump shaft is disposed inside the pinion. That is, the bearing is in the plane containing the pinion and never beside the pinion. However, the bearing may be longer in the axial direction than the pinion width and may protrude from the pinion on one or both sides. For example, the bearing passes through the central hole of the pinion, in particular the pinion and / or pump shaft is rotatably supported by the bearing, which is implemented, for example, as a bearing bush. The arrangement length of the internal gear pump is shortened by arranging the bearing inside the pinion. A further advantage is that the pinion is supported radially by bearings in the plane of the pinion so that an inward force acts on the pinion during operation of the internal gear pump, which inward force causes the fluid to flow outwards. Then, the fluid acts on the pinion, and the fluid is conveyed by the internal gear pump to be pressurized in the pressure chamber between the pinion and the internal gear. The radial force acting on the pinion is supported by bearings arranged inside the pinion without a moment about an axis transverse to the pump shaft. As a result, the additional advantage is obtained that the pump shaft is not bending loaded by radial forces acting on the pinion, which improves the rotation of the pump and reduces bearing wear. Since the pump shaft is not subjected to bending loads, an offset angle and / or radial offset of the drive gear (usually a gear that is relatively non-rotatable on the pump shaft to rotationally drive the pump shaft) is not required. This improves the concentric rotation of the internal gear pump and reduces wear, friction and noise generation on the drive gear. Overall, the pump shaft support accuracy and concentric rotation are improved by the present invention. The present invention allows for relatively large manufacturing tolerances.

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

  According to claim 2, a bearing integral with the case of the internal gear pump is provided, whereby a separate bearing and its mounting are omitted.

  The object of claim 3 is a driving body that couples the pinion to the pump shaft so as not to be relatively rotatable. With this configuration, it is possible to support the rotation of the pinion on the outer surface of the driving body and on the outer surface of the pump shaft provided in the bearing. The driver may be arranged on the side of the pinion and next to the bearing. The pump shaft may penetrate the drive body, or the drive body may be disposed at one end of the pump shaft.

  In order to form the bearing integrally with the case of the internal gear pump, according to claim 4, the case is made of cast iron, for example gray cast iron. This material is excellent in initial formability and cutting workability, and is excellent as a bearing material. This material may have a permanent lubrication in the area of the bearing.

  According to claim 5, the pinion is not arranged directly on the pump shaft, for example, as already mentioned, the pinion is arranged on the outside and the pump shaft is arranged in the bearing, so that the bearing comprises the pinion and the pump shaft. Between.

  The internal gear pump according to the invention is provided in place of a normally used piston pump, in particular as a hydropump for hydraulic, slip-control and / or power-type vehicle brake devices. In the slip control type vehicle brake device, the hydro pump is also called a reverse pump. In this case, the case of the internal gear pump according to the invention is configured in particular for the installation, insertion or press-fitting of the slip control system provided for this into the receiving part of the hydraulic block. In this case, the case of the internal gear pump can be regarded as a cartridge.

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

It is a shaft section perspective view of an internal gear pump by the present invention.

  An internal gear pump 1 according to the present invention shown in the drawings has an internal gear (herein referred to as an internal gear 2) and an external gear (herein referred to as a pinion 3). It is arranged eccentrically in the internal gear 2 so as to mesh with the internal gear 2. Both gears 2 and 3 have parallel axes, have the same width, and are arranged in the same plane. The internal gear 2 is press-fitted into a support ring 4 that is slidably supported in the case 5. The pinion 3 is rotatably slidably supported by a bearing 6, which in the illustrated and described embodiment of the invention is hollow cylindrical, i.e. tubular, and can also be regarded as a support ring or a bearing bush. The bearing 6 is an integral component of the case 5 of the internal gear pump 1. The case 5 and therefore the bearing 6 integral with the case 5 are also made of gray cast iron for suitable cutting workability and suitability as a bearing material, and are provided with permanent lubrication portions inside and outside the bearing 6. The gray cast iron for the case 5 of the internal gear pump 1 according to the present invention is not compulsory, and the case 5 with the bearing 6 may be made of other metallic or non-metallic materials.

  The peripheral part in which the gears 2 and 3 are engaged with each other is cut away in the axial section shown and is therefore not visible. What can be seen is a peripheral portion of the gears 2 and 3 where the gears 2 and 3 are not engaged with each other. In this peripheral portion, there is a crescent-shaped intermediate space between the internal gear 2 and the pinion 3, and this crescent-shaped intermediate space is referred to as a pump chamber 7 here. A partition member 8 that divides the pump chamber 7 into a suction chamber 9 and a pressurizing chamber 10 is disposed in the pump chamber 7. The partition member 8 has a crescent shape and is therefore also called a crescent or crescent member, and another name for the partition member 8 is a filling member. The partition member 8 has the same width as the gears 2 and 3, and the outer surface and the inner surface of the partition member 8 are convex or concave so that the tooth tips of the gears 2 and 3 abut against the outer surface and the inner surface of the partition member 8. Is. When the gears 2 and 3 are driven to rotate, the tooth tips of the gears 2 and 3 slide along the inner surface and the outer surface of the partition member 8, and the gears 2 and 3 suck the fluid in the tooth intermediate space 9. Are conveyed in a known manner along the outer and inner surfaces of the partition member 8 into the pressure chamber 10. When the internal gear pump 1 is used as a hydropump of a hydraulic vehicle brake device, the fluid is a liquid, that is, a brake fluid.

  On both sides of the gears 2, 3 and the partition member 8, a plurality of axial disks 11 that are not relatively rotatable and are movable in the axial direction are arranged. The axial disk is in contact with the gears 2 and 3 and the end face of the partition member 8 and covers the pump chamber 7 from the side at least in the region of the pressurizing chamber 10 and the region of the partition member 8. The upper axial disk is not shown because it covers the gears 2 and 3 and the partition member 8 of the internal gear pump 1. Such an axial disk 11 is known and is also called a control disk or a pressure plate.

  The internal gear pump 1 has a pump shaft 12 that is slidably supported in a tubular bearing 6 so as to rotate. The pump shaft 12 is sealed by a shaft seal ring 13 provided in the case 5 on the side near the pinion 3 and the illustrated axial disk 11, and on the side of the shaft seal ring 13 opposite to the pinion 3, The other bearing 14 is rotatably supported in the case 5. In the illustrated embodiment of the present invention, the other bearing 14 is a ball bearing, but this is not necessarily mandatory for the present invention. In order to drive the internal gear pump 1, the gear as the drive gear 15 is pressed to the end of the pump shaft 12 on the end surface side of the case 5, or is fixed to the pump shaft 12 in a non-rotatable manner in another manner. Yes.

  The bearing 6 is inside the pinion 3 and passes through the central hole of the pinion 3. The central hole is described here as a support hole 20, and the pinion 3 is slidably supported by the bearing 6. Although sliding support is advantageous, it is not mandatory for the present invention. By rotating and supporting the pinion 3 using the bearing 6 inside the pinion 3, that is, by rotating and supporting the pinion 3 in one plane including the pinion 3, the pinion 3 has a radius within this plane where the pinion 3 is provided. Supported in direction. During operation of the internal gear pump 1, the pressure that urges the pinion 3 radially inward is dominant in the pressurizing chamber 10. The pinion 3 is supported in the radial direction in the same plane as the surface on which the pinion is pressure-biased by the bearing 6 arranged inside the pinion 3 against the pressure bias in the radial direction. Therefore, the radial support of the pinion 3 receives no moment, and in particular, the tilting moment around the virtual axis in the radial direction does not act on the axis of the pinion 3. Similarly, bending stress of the pump shaft 12 is also avoided.

  In order to drive the pinion 3 by the pump shaft 12 for the purpose of operating the internal gear pump 1, the internal gear pump 1 has a drive body 16 that couples the pinion 3 to the pump shaft 12 so as not to be relatively rotatable. ing. In the embodiment of the invention shown and described here, the drive body 16 is arranged at the end of the pump shaft 12 away from the drive gear 15. In the embodiment of the present invention shown and described herein, the driver 16 is a plate punching member, bending member or deep drawing member having a triangular or three-star shape, and has a rectangular shape at its corners. The bending connecting member 17 engages with a pocket provided in the support hole 20 of the pinion 3, whereby the driving body 16 is coupled to the pinion 3 so as not to rotate relative to the pinion 3. The pocket is a flat recess provided in the support hole 20 of the pinion 3. The driving body 16 overlaps with the annular end surface of the bearing 6 and has a flat curved portion 18 formed by deep drawing in the center thereof and having a substantially square shape when viewed in the axial direction. It engages with a square settling part 19 provided at the center of the end face. The curved portion 18 integrated with the drive body 16 is coupled to the pump shaft 12 so as not to rotate relative to the pump shaft 12 by shape coupling at a square settling portion 19.

  Since the internal gear pump 1 is used for slip control of a hydraulic vehicle brake device, the cylindrical case 5 that can be regarded as a cartridge has a cylindrical receiving portion complementary to a hydraulic block (not shown). It is press-fitted. Such hydraulic blocks are known per se from hydraulic vehicle brake slip control and typically include two receptacles for two internal gear pumps 1, solenoid valves, hydro accumulators and the like. A block of aluminum, with other receptacles for the hydraulic components of a simple slip control system. Through the pilot hole in the hydraulic block, the receiving part or the hydraulic components inserted into the receiving part are hydraulically connected to each other.

DESCRIPTION OF SYMBOLS 1 Internal gear pump 2 Internal gear 3 Pinion 5 Case of internal gear pump 6 Bearing 12 Pump shaft

Claims (4)

An internal gear (2), a pinion (3) arranged eccentrically in the internal gear (2) and meshing with the internal gear (2), the pinion (3) and the internal gear ( 2) and a bearing (6) rotatably supporting the pump shaft (12) and / or the pinion (3). The bearing (6) is disposed inside the pinion (3) ,
The internal gear pump, wherein the bearing (6) is integral with a case (5) of the internal gear pump (1) . The said internal gear pump (1) has the drive body (16) which couple | bonds the said pinion (3) and the said pump shaft (12) so that relative rotation is impossible. The internal gear pump according to claim 1. The internal gear pump according to claim 1, characterized in that the case (5) of the internal gear pump (1) is made of gray cast iron . 2. Internal gear pump according to claim 1 , characterized in that the pinion (3) is not arranged directly on the pump shaft (12) .

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