JP2015514915A - Internal gear pump - Google Patents

Abstract

The present invention relates to an internal gear pump (1) having a leg spring as a separating piece (7) between a suction side (8) and a pressure side (9). The present invention relates to the transition of the central region (a, b) of the leg (13, 14) of the separating piece (7) from the free end of the separating piece (7) to the yoke (15). Of the gear (2, 3) of the internal gear pump (1) with a high initial stress until the leg (13, 14) reaches its free end. It is proposed to contact the tooth tip. In order to reduce the mechanical stress in the region of the yoke (15) of the separating piece (7), a large curvature is intended at the transition (c, d) from the leg (13, 14) to the yoke (15). The [Selection] Figure 1

Description

  The present invention relates to an internal gear pump comprising the constituent features of the preamble of claim 1.

  Patent Document 1 discloses a hydraulic vehicle brake equipment having a ring gear with internal teeth and a pinion with external teeth arranged eccentrically in the ring gear so as to mesh with the ring gear in one circumferential area. An internal gear pump is disclosed. The ring gear is a gear with internal teeth, the pinion is a gear with external teeth, and the names pinion and ring gear are selected for distinction. The ring gear and the pinion can be combined to be called an internal gear pump gear. Outside the circumferential area where the pinion and the ring gear mesh with each other, the pinion and the ring gear divide the crescent-shaped pump chamber between each other, and the suction side of the internal gear pump is pumped from the pressure side to this pump chamber. Separating pieces that are separated from each other in the chamber are arranged. The separating piece of the known internal gear pump is a leg spring with a width equal to each gear of the internal gear pump. The inner and outer legs of the separation piece are curved according to the gears of the internal gear pump, the tooth tip of the pinion abuts the inner leg, and the tooth tip of the ring gear is the leg. Abuts on the outer leg of the separating piece configured as a spring, so that the liquid is surrounded in the middle space of each gear tooth and is driven from the suction side in a manner known per se by the rotational drive of each gear. It is sent out to the pressure side. Both legs of the separating piece are unitary and are connected to each other in a resilient manner by a yoke.

  About the name: The inside of the leg of the separating piece is the side of each leg facing each other. The outside of the leg abuts against the tooth tip of each gear.

German Patent Application No. 102007049704A1

  The separation piece of the internal gear pump of the present invention having the constituent elements of claim 1 is also configured as a leg spring having leg portions that contact the tooth tips of the pinion and ring gear. Each leg is thicker than the respective free end and the transition of the separating piece to the yoke in the respective central region. Each leg tapers from the thick central region toward the free end and toward the transition to the yoke. The central region of each leg of the separating piece extends in the longitudinal direction of the leg, that is, extends in the circumferential direction of the internal gear pump and each of its gears. The central region of the leg ends at a distance from the free end of the leg and ends at a distance from the transition from the yoke to the leg. The central region does not have to be in the longitudinal center of the leg, but may be near the free end or the transition to the yoke. Depending on the thickness distribution of the legs of the separating piece, the spring stiffness of the legs changes over its length.

  The invention improves the abutment of the leg of the separating piece, which is configured as a leg spring, against the tooth tip of the gear of the internal gear pump, and accordingly improves the sealing of the intermediate space of the teeth. The legs of the separating piece of the internal gear pump according to the invention make better contact with the gear teeth over the entire length. In the prior art, the leg portion of the separation piece is substantially pressed against the tooth tip of the gear of the internal gear pump in the vicinity of the yoke based on the spring force of the separation piece. In the internal gear pump, the spring force of the separation piece presses the leg portion against the tooth tip even in the region of its free end. In an advantageous case, the leg is pressed evenly against the tooth tip throughout its length. The crimping force of the leg of the separation piece against the tooth tip of the gear of the internal gear pump based on the spring force of the separation piece configured as a leg spring is as grasped as it is, or inscribed Considering the internal pressure due to the hydraulic pressure between the legs during the operation of the gear pump, this internal pressure is constant over the length of the leg, and therefore a constant force is applied over the length of the leg. The inner leg is raised inward in the radial direction and the outer leg is raised outward.

  It is also possible to provide the thickness distribution and shape of the leg portion of the separation piece in which the pressure-bonding force of the leg portion against the tooth tip of the gear of the internal gear pump increases in the direction of the free end of the leg portion. In this case, the crimping force of the leg of the separation piece increases in the direction toward the pressure side of the internal gear pump, thereby acting to prevent the leg from contacting the tooth tip. It becomes large where the hydraulic pressure in the intermediate space is large. Thereby, the sealing action can be improved.

  The dependent claims are directed to preferred embodiments and developments of the invention as defined in claim 1.

  The object of claim 7 is a curved shape on the outer side and inner side or outer surface and inner surface of the separation piece in the region of the yoke and in the region of the transition part from the yoke to the leg part integral with the yoke. At the transition from the yoke to the leg, the outer side of the separation piece is convexly arcuate, that is, the outer surface is a convex cylindrical surface. Between the transition portions to the respective leg portions, the outer surface of the yoke of the separation piece is curved in a concave cylindrical shape. At the transition from the yoke to the inner leg, the inner surface of the separation piece is concavely curved in a cylindrical shape, and this radius of curvature is greater than the radius of curvature at the outer side of the transition from the yoke to the inner leg. Is also big. The exact cylindrical shape is not important. This embodiment of the present invention improves the yoke area and the transition from the yoke to the leg of the separating piece with respect to the mechanical stress acting on the separating piece, and the mechanical stress is better distributed. In addition, locally high stresses are avoided or mechanical stress peaks are reduced.

  The constituent features of claim 7 may be embodied without the constituent features of the characterizing portion of the main claim in the embodiment of the present invention.

  Next, the present invention will be described in detail with reference to the embodiments shown in the drawings. The drawing shows the following:

It is a side view which shows the internal gear pump by this invention. FIG. 2 is an enlarged view showing a partial piece of the internal gear pump of FIG. 1 according to the present invention as a single part.

  The drawings are to be understood as schematic and simplified figures for understanding and explanation of the present invention.

  The internal gear pump 1 according to the present invention shown in FIG. 1 has two gears 2, 3, that is, a ring gear 2 with internal teeth and a gear with external teeth, here called a pinion 3. doing. The pinion 3 is eccentrically arranged in the ring gear 2, and both gears 2, 3 have axes parallel to each other and mesh with each other. The ring gear 2 is rotatably supported by a bearing ring 4, and the pinion 3 is disposed on the pump shaft 5 so as not to rotate. For clarity of illustration, the housing of the internal gear pump 1 is not shown. In order to operate the internal gear pump 1, the pump shaft 5 is rotationally driven, and the pinion 3 that cannot be rotated by the pump shaft 5 rotates together with this to rotationally drive the meshed ring gear 2. The direction of rotation is indicated by arrow P.

  The gears 2 and 3 surround the crescent-shaped pump chamber 6 between each other in a circumferential area where the gears 2 and 3 are not meshed with each other. The pump chamber 6 can be grasped as a partial crescent shape or a half crescent shape, and a crescent-shaped separation piece 7, which is often referred to as a crescent or a crescent body, is arranged. The separation piece 7 separates the suction side 8 from the pressure side 9 in the pump chamber 6 of the internal gear pump 1. An intake hole 10 communicates with the suction side 8, and a discharge hole 11 communicates with the pressure side 9. The tooth tips of the gears 2 and 3 of the internal gear pump 1 are in contact with the outside or the inside of the separation piece 7, and when the gears 2 and 3 are driven to rotate, they slide along the outside or the inside of the separation piece 7. Move. The separating piece 7 has the same width as the gears 2 and 3, and these gears both have the same width. The separating piece 7 surrounds the liquid volume in the middle space of the teeth of the gears 2, 3, so that the rotational drive of the gears 2, 3 causes the delivery of liquid from the suction side 8 to the pressure side 9. The separation piece 7 is supported by a bolt called a receiving portion 12 which penetrates the pump chamber 6 sideways at the end portion on the suction side.

  In the present embodiment, the crescent-shaped separation piece 7 is a leg spring. The leg spring is a U-shaped leaf spring having two leg portions 13 and 14 that are curved in an arc shape in the same direction. As described above, the leg springs of the teeth of the gears 2 and 3 are provided on these leg portions. The tip contacts. The tooth tip abuts on the outside of the leg portions 13, 14, and the outside of the leg portion 13 inside the separating piece 7 faces inward with respect to the internal gear pump 1, and forms the inside of the separating piece 7. The inner sides of the leg portions 13 and 14 of the separation piece 7 face each other. A yoke 15 connects both the leg portions 13 and 14 and abuts against the receiving portion 12. The leg springs forming the separating piece 7 are open at the pressure side end, so that the internal space 16 between the leg spring legs 13, 14 is urged by the pressure generated on the pressure side 9, This pressure urges the outer legs 14 away from the legs 13, 14, that is, outwards toward the teeth of the teeth of the ring gear 2, and the inner legs 13 inwardly the pinion 3. Energize toward the tip of the teeth. Thereby, the leg portions 13 and 14 of the leg springs forming the separating piece 7 of the internal gear pump 1 can be added to the tooth tips of the gears 2 and 3 of the internal gear pump 1 even when the pressure condition is changed. Always abuts to seal. In addition to this, the legs 13 and 14 abut against the tooth tips of the gears 2 and 3 with initial stress based on the spring force of the separating piece 7 configured as a leg spring, that is, for example, the internal gear pump 1. Abuts even when there is no pressure.

  The leg of the separating piece 7 has a thickness that varies over its length, and thus has a spring stiffness that varies over its length. The shape and thickness transition of the separation piece 7 can be seen well in FIG. 2 showing the separation piece 7 as a single part. The inner leg portion 13 is thicker than the free end far from the yoke 15 in the central region a, and is thicker than the transition portion c to the yoke 15. The central region a ends at a distance from the free end and ends at a distance from the transition portion c from the yoke 15 to the inner leg 13. In this embodiment, the thick central region a of the inner leg is not symmetric with respect to the longitudinal center of the inner leg 13, but is closer to the free end. However, this is not mandatory for the present invention. The inner leg 13 tapers not only from the central region a toward the free end but also toward the transition c with the yoke 15. Due to the relatively large thickness, the inner leg 13 of the separating piece 7 has a relatively high spring stiffness in its central region a. In this embodiment, the thickness of the inner leg portion in the central region a and the resulting spring stiffness are substantially constant, but this is not compulsory for the present invention. It can be understood that the central region a of the inner leg 13 has a plateau shape. The inside of the inner leg 13 facing towards the outer leg 14 is not only towards the free end of the inner leg 13 at both ends of the central area a, but also the yoke of the separating piece 7. Also in the direction of the transition part c to 15, it is first convex and then concave.

  The outer leg 14 also has a central area b, in which the outer leg 14 is thick, and the spring stiffness is also transferred to its free end or yoke 15 accordingly. It is higher than the part d. However, the outer leg portion 14 does not have a constant thickness in the central region b, but the thickness continuously increases from the transition portion d to the yoke 15 from the central region b to the free end thereafter. It is decreasing again. The thickest portion of the outer leg portion 14 may be substantially at the longitudinal center of the leg portion 14. In this embodiment, the thickest portion is closer to the free end than the yoke 15. The thickness distribution of the outer leg 14 is realized by an outer convex curve that is stronger than the inner concave curve. The outer side is in contact with the tooth tip of the ring gear 2 and is circular, that is, the outer surface is cylindrical. The inside of the outer leg 14 has a weaker curvature in the central region b than towards the free end and the yoke 15. The concave curvature on the inside of the outer leg 14 is weaker than the convex curvature on the outside. A relatively large thickness in the central region of the leg 14 is realized by the inner shape and position relative to the circular outer side, and is also possible by the circular inner side, the inner radius of curvature being smaller than the outer radius of curvature. Preferably not.

  In the present embodiment, the thickest portion of the inner and outer legs 13 and 14 is the thickest portion of the separation piece 7.

  The shaping of the legs 13 and 14 of the separating piece 7 having a relatively thick central area a and b, in particular the thickness distribution, is such that the legs 13 and 14 have a substantially constant initial stress over their entire length. This results in a contact with the tip of a few teeth. Due to the thick central regions a and b, the leg portions 13 and 14 can contact the tooth tips of the gears 2 and 3 with relatively high initial stress even near the free end far from the yoke 15. That is, that is, even on the pressure side 9 where the pressure in the middle space of the teeth of the gears 2 and 3 is high, the leg portions 13 and 14 of the separating piece 7 abut against the tooth tip with initial stress, and in the middle space of the tooth Enclose the hydraulic fluid.

  In the transition portions c and d from the yoke 15 to the leg portions 13 and 14, the separation piece 7 is curved in a convex shape in an arc shape on the outside, and is curved in a concave shape in a circular arc shape between the transition portions c and d. ing. That is, the outer surface of the separation piece 7 is a convex cylindrical surface at the transition portions c and d from the yoke to the leg portions 13 and 14, and the outer surface of the yoke 15 is between the transition portions c and d. It is a concave cylindrical surface. Inside the separation piece 7, the transition part c from the yoke 15 to the inner leg part 13 is concavely arcuate, that is, the inner surface is concave at the transition part c from the yoke 15 to the inner leg part 13. It has a cylindrical surface. The radius is larger than the radius outside the transition portions c and d from the yoke 15 to the leg portions 13 and 14. The radius on the inside of the transition c from the yoke 15 to the inner leg 13 is greater than half of the maximum spacing between both legs 13,14. By providing such a shape of the separation piece 7 in the region of the yoke 15 and in the region of the transition portions c and d from the yoke 15 to the legs 13 and 14, the transition from the region of the yoke 15 and the yoke 15 to the legs 13 and 14. The mechanical stresses in the areas of the parts c, d are reduced and distributed evenly or at least relatively evenly. This mechanical stress is caused by the initial stress at which the legs 13 and 14 abut against the tooth tips of the gears 2 and 3 of the internal gear pump 1, and pressure urging by hydraulic fluid from the outside and the inside. Elicited by. At the yoke 15 and at the transitions c, d to the legs 13, 14, the mechanical stress at the separating piece 7 is highest, so at these points the mechanical stress is distributed as evenly as possible, The geometry of the separating piece 7 that avoids locally high stresses is important or at least preferred.

  The internal gear pump 1 is intended as a hydropump for hydraulic vehicle brake equipment, in particular for slip control of hydraulic vehicle brake equipment and / or for hydraulic external force vehicle brake equipment. It is intended as a so-called return pump for generating pressure.

DESCRIPTION OF SYMBOLS 1 Internal gear pump 2 Ring gear 3 Pinion 6 Pump chamber 7 Separation piece 8 Suction side 9 Pressure side 13 Inner leg 14 Outer leg 15 Yoke 16 Internal space

Claims (8)

  An internal gear having a ring gear (2) with internal teeth, and a pinion (3) with external teeth arranged eccentrically in the ring gear (2) and meshing with the ring gear (2) in one circumferential section A gear pump, wherein the ring gear (2) and the pinion (3) pass between crescent-shaped pump chambers (6) between each other outside the circumferential area where the pinion (3) meshes with the ring gear (2). A separating piece (7) for separating the suction side (8) from the pressure side (9) in the pump chamber (6) is arranged in the pump chamber, and the separating piece (7) A curved inner leg (13) that abuts against the tooth tip of the pinion (3), and a curved outer leg (14) that abuts against the tooth tip of the ring gear (2); A yoke (15) connecting both the legs (13, 14). In such an internal gear pump, the legs (13, 14) are thick in the central region (a, b) and towards their free ends and from the legs (13, 14). An internal gear pump characterized by tapering toward the transition part (c, d) to the yoke (15).   2. Internal gear pump according to claim 1, characterized in that the separating piece (7) has a maximum thickness in the central region (a, b) of the leg (13, 14).   2. Internal gear pump according to claim 1, characterized in that the inner leg (13) of the separating piece (7) has a substantially constant thickness in its central region (a).   The inner side of the inner leg part (13) of the separating piece (7) is the transition part (c) from the yoke (15) to the inner leg part (13) and the central area of the inner leg part (13). Internal gear pump according to claim 1, characterized in that it is curved concavely between and between the free end of the inner leg (13) and the central region (a).   The concave curvature on the inner side of the outer leg (14) of the separating piece (7) is at least as large as the outer convex cylindrical curve, preferably larger than this. The internal gear pump according to claim 1.   The concave curvature inside the leg (14) outside the separating piece (7) is reduced in the central region (b) of the leg (14), and is free from the free end and the yoke (15). 6. Internal gear pump according to claim 5, characterized in that it increases towards the transition part (d).   The separation piece (7) has a cylindrically convex outer surface at the transition portion (c, d) from the leg (13, 14) to the yoke (15), and a cylindrical concave surface therebetween. The transition part (c) from the inner leg (13) to the yoke (15) has a cylindrically concave inner surface, and its radius is on the inner side. 2. Internal gear pump according to claim 1, characterized in that it is larger than the radius of curvature of the outer surface at the transition (c) from the leg (13) to the yoke (15).   The internal space (16) of the separating piece (7) between the inner leg (13) and the outer leg (14) communicates with the pressure side (9) of the pump chamber (6). The internal gear pump according to claim 1, wherein the internal gear pump is characterized.

Images