JP2015500953A - Inscribed gear pump - Google Patents

Abstract

An internal gear pump for pumping fluid, having an inner gear (22) having an internal ring gear, and having an outer gear (24) having an external ring gear, the inner gear and the outer gear The plurality of teeth (21) of (22, 24) mesh with each other, and the inner gear (22) or the outer gear (24) is driven, and the inner gear (22) and the outer gear (24) A work space (47) is formed between them, and the work space (47) is divided into an inflow work space (30) and an outflow work space (31). An inflow passage (28) that opens into the inflow work space (30) for introduction into the space (30), and a fluid to be pumped in the outflow work space. 31) and an outflow passage (29) that opens into the outflow work space (31), and the plurality of teeth (21) of the inner gear (22) and the outer gear ( 24) each of the plurality of teeth (21) has a drive side surface (51) and a free side surface (52) opposite to the drive side surface (51), and the inner gear (22) In order for the drive side surface (51) and the drive side surface (51) of the outer gear (22) to transmit torque from the driven gear (22, 24) to the non-driven gear (22, 24), In this case, the shape of the drive side surface (51) of the inner gear and / or outer gear (22, 24) is at least 2 of the inner gear and outer gear (22, 24). Of the inner gear (22) and the teeth (21) of the outer gear (24) between the teeth (21) of the inner gear (22) and the teeth (21) of the outer gear (24). Configured such that there is a gap or play. [Selection] Figure 4

Description

  The present invention relates to an internal gear pump according to the preamble of claim 1 and a high-pressure injection system according to the preamble of claim 12.

  The internal gear pump or trochoid pump has an inner gear and an outer gear. A plurality of teeth of the inner gear and the outer gear mesh with each other to form a work space between the inner gear and the outer gear. In this case, the work space is divided into an inflow work space and an outflow work space. Accordingly, the inflow work space forms the suction side of the inscribed gear pump, and the outflow work space forms the discharge side. An inflow passage opens in the inflow work space, and an outflow passage opens in the outflow work space. In this case, one gear is driven, and torque is transmitted from the driven gear to the non-driven gear at one contact point of the teeth of the inner gear and the outer gear. At this point of contact, the driving side surfaces of the two teeth that come into contact overlap each other.

  A tooth tip portion facing the meshing portion exists between the inner gear and the outer gear. At the tooth tip, torque is not transmitted from the outer gear to the inner gear, and leakage loss occurs between the inflow work space and the outflow work space. That is, the fluid under pressure flows from the outflow work space into the inflow work space. In order to correct manufacturing accuracy and thermal deformation, leakage occurs due to the provision of play between the inner gear and the outer gear at the tooth tip.

  It is also known to apply a preload pressure to the inner gear and the outer gear in the region of the tooth tip according to the so-called “Eckerle principle“ Eckerle-Prize ””. This can avoid or reduce leakage loss at the tip of the tooth, but the teeth of the inner and outer gears are heavily worn, and the mechanical friction loss at the tip of the tooth is significantly increased. As a result, the efficiency of the inscribed gear pump decreases or the energy loss increases.

  In this case, based on theoretical mathematical operations, it is possible to configure the inner and outer gears so that all teeth of the inner gear are in contact with all teeth of the outer gear. There is no leakage. For example, the plurality of teeth of the outer gear have a circular arcuate shape as viewed in a cross-sectional view perpendicular to the rotation axis of the outer gear, and the inner gear has a shape based on the shape of the plurality of teeth of the outer gear. Multiple tooth configurations are obtained. This is described in Non-Patent Document 1, for example. However, this type of gear pump cannot actually be manufactured. Because it is impossible to assemble based on manufacturing accuracy and thermal deformation, and very high preload pressure and friction loss occur between the inner gear teeth and the outer gear teeth during operation. is there.

  According to Patent Document 1, a vane pump or an inner-bearing gear pump having a plurality of closed pumping chambers is known, and the volume of the pumping chamber is reversed from a minimum value to a maximum value during a rotational movement and reversed. Changes from the maximum value to the minimum value. This pump is used in particular for fuel pumping of internal combustion engines. This pump has a suction passage and a discharge passage that enter the pressure feed chamber in the axial direction, and the opening cross section of the suction passage and the discharge passage is designed to pump without an inner seal. The inner seal is obtained by a stationary thrust washer that forms a check valve applied to the axial face of the pump part.

  According to Patent Document 2, a positive displacement machine having at least two gear machines is known, and a hydraulic circuit specific to or common to the gear machine is arranged correspondingly, and a common pumping flow of the gear machine is disclosed. Can be changed by a control member, which is arranged in the housing part of the positive displacement machine.

  Patent Document 3 discloses an internal gear pump including at least one ring gear having internal teeth and a rotor having external teeth meshing with the ring gear. The internal gear pump further includes a crescent (crescent shaped). Member) or not, and an electric drive device is provided. In this electric drive device, the ring gear is arranged inside the rotor of the brushless electric motor, and the stator is adjacent to the rotor. In this case, the rotor including the ring gear is held eccentrically and rotatably in a bearing or a sliding bearing, and the stator is relative to the rotor and to the interior of the pump. By being shielded and sealed against each other, the bearing or the sliding bearing existing between the stator and the rotor does not allow liquid to pass through, and the both end surfaces can be used. It is sealed connected to each closure cover Te.

German Patent No. 3624532 German Patent Publication No. 3406349 German Utility Model Registration No. 29913367

"Modeling and learning of a new pump concept for braking systems" by Boris Mathieu, Ecole superieur des sciences et technologies de l'ingenieur de Nancy 2 (Modeling Diplom or master thesis on the theme of and a new pump concept for braking systems, Rue Jean Lamour, 54519 Vandoeuvre les Nancy Cedex, 2005 February 14-August 12, 2005

  An internal gear pump for pumping fluid according to the present invention, particularly for automobiles, has an inner gear with an internal ring gear and an outer gear with an external ring gear. A plurality of teeth of the outer gear mesh with each other, the inner gear or the outer gear is driven, and a work space is formed between the inner gear and the outer gear, and the work space includes the inflow work space and the outflow work space. And an inflow passage that opens into the inflow work space for introducing the fluid to be pumped into the inflow work space, and for deriving the fluid to be pumped from the outflow work space. An outflow passage that opens into the outflow work space, preferably the inflow work space and the outflow work space. It is separated from each other at the tooth tip portion and the meshing portion between the inner gear and the outer gear, and the plurality of teeth of the inner gear and the plurality of teeth of the outer gear are respectively on the driving side surface and the opposite side of the driving side surface. The drive side of the inner gear and the drive side of the outer gear overlap each other in order to transmit torque from the driven gear to the non-driven gear. Alternatively, the shape of the driving side surface of the outer gear is such that at least two teeth of the inner gear and the outer gear are overlapped with each other, and at the tooth tip portion, the interval between the plurality of teeth of the inner gear and the plurality of teeth of the outer gear, or It is configured so that there is play. Thereby, in a preferred manner, the teeth of the inner and outer gear are in contact with each other so that, on the one hand, when the teeth overlap or contact each other on the drive side, No leakage occurs in the area of the work space, on the other hand, by the presence of play or spacing at the tip location and in the vicinity of the tip location between the teeth of the inner and outer gears, The inner gear and the outer gear can be assembled, and very little preload pressure and friction loss are generated between the teeth of the inner gear and the outer gear.

  According to additional embodiments, the shape of the free side surface of the inner gear and / or outer gear is configured such that the teeth of the inner gear and outer gear have spacing or play on the free side surface. Thereby, in a preferred manner, there is virtually no frictional force or preload pressure on the free side, very little preload pressure is generated on the drive side, and the preload pressure is substantially reduced by the driven gear. Corresponds only to the pressing force required for transmission from the gear to the non-driven gear.

  According to another variation, the plurality of teeth of the inner gear and the plurality of teeth of the outer gear have tooth tips, and the shape of the tooth tips of the inner gear and / or outer gear is determined by the plurality of teeth of the inner gear. The tooth tips of the outer gear are not in contact with the teeth of the outer gear, in particular the tooth tips, and the free sides of the teeth, and / or the tooth tips of the teeth of the outer gear are It is configured so as not to contact the teeth, in particular the tooth tips, and the free sides of the teeth. Thereby, in a preferred manner, substantially no preload pressure and friction force are generated at the tooth tip, particularly at the tooth tip location.

  In a preferred form, the tooth tips of the inner and outer gear teeth are of radial dimensions of the inner gear and outer gear teeth toward the rotational axis of the respective inner gear and outer gear. The last 30%, 20% or 10%, preferably the drive side and / or the free side are formed outside the tooth tips of the inner and outer gear teeth.

  According to a supplementary variation, the spacing or play between the teeth of the inner gear and the outer gear at the free side surfaces and / or the tooth tip locations of the teeth of the inner gear and the outer gear is at least 5 μm, 10 μm. , 20 μm, 40 μm or 60 μm and / or less than 200 μm, 150 μm, 100 μm or 80 μm and / or between 10 μm and 150 μm, in particular between 20 μm and 100 μm. This amount of play or spacing is necessary to compensate for manufacturing accuracy and thermal deformation.

  According to additional embodiments, the shape of the drive side of the inner gear and / or outer gear is configured such that at least three, four or five teeth of the inner gear and outer gear overlap each other. This ensures that no leakage occurs in a wide area of the inflow or outflow work space.

  Preferably, the inscribed gear pump is a trochoid pump.

  According to another embodiment, the inscribed gear pump has an electric motor including a stator and a rotor, and the driven gear is formed by the rotor.

  According to a supplementary embodiment, a permanent magnet of the rotor is mounted or incorporated in the driven gear.

  In a preferred form, the stator is formed concentrically around the rotor.

  According to another embodiment, the outer gear or the inner gear is formed by a rotor.

  In particular, a permanent magnet of the rotor is attached or incorporated in the outer gear or the inner gear.

  According to another embodiment, the inflow passage is only partially open into the inflow work space having an expanding volume, and the outflow passage is in the outflow work space with a contracting volume, and even partially. Opened into the inflow work space.

  According to an additional variation, the inflow angle range is equal to or greater than the pressure angle range, the outflow angle range is greater than 180 °, so there are no contacts in the seal angle range, and the preferred form All contacts are in the inflow angle range, or the inflow angle range is smaller than the pressure angle range and the outflow angle range is greater than 180 °, so that the contacts are in the seal angle range. If there is no contact in the seal angle range between the inflow angle range and the outflow angle range, there will be little leakage between the inflow passage and the outflow passage due to small play or small spacing. In this case, the play or spacing of the last contact gradually increases towards the tooth tip of the tooth at the tooth tip location. For example, if the first tooth behind the last tooth is provided in the seal angle range when viewed in the direction toward the tip of the tooth tip, a slight leak will occur based on a slight play or a small interval. If the contact is provided in the seal angle range, substantially no leakage occurs between the inflow passage and the outflow passage. This is because, in the contact, almost perfect sealing is guaranteed based on the contact.

  According to a supplementary embodiment, the outflow passage is only partially open into an outflow work space having a decreasing volume, and the inflow passage is open into an inflow work space having an expanding volume. Furthermore, it opens partially in the outflow work space.

  According to another embodiment, the outflow angle range is equal to or greater than the pressure angle range, and the inflow angle range is greater than 180 °, so that there is no contact in the seal angle range, and preferably All contacts are in the outflow angle range, or the outflow angle range is smaller than the pressure angle range and the inflow angle range is greater than 180 °, so that the contacts are in the seal angle range.

  According to a supplementary variation, the pressure angle range starts at the meshing location in the running direction for the driven inner gear and starts from the meshing location in the direction opposite to the travel direction for the driven outer gear. Yes.

  In a preferred form, the teeth have only one virtual contact at the meshing point.

  According to another embodiment, the inflow angle range and the outflow angle range extend in opposite directions starting from the meshing location, preferably the inflow angle range ends at the end of the inflow passage, and the outflow angle range is Preferably, it ends at the end of the outflow passage or, alternatively, the inflow angle range is provided only in the inflow passage and the outflow angle range is provided only in the outflow passage.

  The high-pressure injection system according to the invention, in particular for an internal combustion engine for motor vehicles, comprises a high-pressure pump, a high-pressure rail, and preferably an electric feed pump for pumping fuel from a fuel tank to the high-pressure pump. This feed pump is configured in accordance with the feed pump described in this patent specification.

  According to a variant embodiment, the inner gear and the outer gear are bearing eccentrically with respect to each other.

  In a preferred form, the pump, preferably with a built-in motor, advantageously has an electronic control unit for controlling the power supply to the electromagnet and / or the pump motor is an electronically commutated motor. It is.

  In a preferred manner, the housing of the feed pump and / or the housing of the high-pressure pump and / or the inner and / or outer gear are at least partly made of metal, for example steel or aluminum.

  In a preferred form, the pressure angle range corresponds to the size of the inflow or outflow passage.

  In particular, the discharge amount of the electric feed pump can be controlled in an open loop and / or closed loop.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

1 is a highly simplified view of a high pressure injection system. It is a perspective view of the internal gear pump except a housing and a stator. FIG. 3 is an exploded view of the inscribed gear pump shown in FIG. 2. FIG. 3 is a cross-sectional view of the inscribed gear pump shown in FIG. 2 in which a permanent magnet is incorporated in the inner gear. FIG. 3 is a cross-sectional view of the internal gear pump shown in FIG. 2 in which a permanent magnet is incorporated in the inner gear, and an inflow passage and an outflow passage are configured differently from FIG. 2. It is a figure which shows the detail of the tooth tip part of the internal type gear pump shown to FIG. 4 and FIG.

  FIG. 1 shows a pump device 1 of a high-pressure injection system 2 for a vehicle not shown. The electric feed pump 3 pumps fuel from the fuel tank 41 through the fuel pipe 35. Next, the fuel is pumped from the electric feed pump 3 to the high-pressure pump 7. The high pressure pump 7 is driven by the internal combustion engine 39 via the drive shaft 44.

  The electric feed pump 3 has an electric motor 4 and a pump 5 (FIGS. 2 and 3). The electric motor 4 of the pump 5 is incorporated in the pump 5, and the electric feed pump 3 is directly disposed on the high-pressure pump 7 (not shown). The high-pressure pump 7 pumps fuel to the high-pressure rail 42 through the high-pressure fuel pipe 36 under high pressure, for example, under pressure of 1000, 3000 or 4000 bar. From the high-pressure rail 42, fuel is supplied to a combustion chamber (not shown) of the internal combustion engine 39 by an injector 43 under high pressure. Fuel that does not need to be burned is guided back to the fuel tank 41 by the fuel return pipe 37 again. The fuel is sucked from the fuel tank 41 through the fuel pipe 35 through the inflow passage 28 (FIGS. 3 and 4) of the electric feed pump 3, and the fuel is supplied to the high-pressure pump 7 through the fuel pipe 35 through the outflow passage 29. Supplied.

  A fuel filter 38 is incorporated in a fuel pipe 35 that leads from the fuel tank 41 to the electric feed pump 3. In this way, the fuel pipe 35 that leads from the fuel tank 41 to the electric feed pump 3 can be constructed at a low cost. This is because the fuel pipe 35 does not need to overcome the overpressure. The electric motor 4 (FIGS. 3 and 4) of the electric feed pump 3 is driven by three-phase alternating current or alternating current, and the output can be controlled in an open loop and / or closed loop. Three-phase alternating current or alternating current for the electric motor 4 is provided from a DC voltage network of an in-vehicle power source of the automobile 40 by power electronics (not shown). Therefore, the electric feed pump 3 is an electronically rectified feed pump 3.

  The electric feed pump 3 has a housing 8 having a bowl-shaped housing 10 and a housing cover 9 (FIG. 3). Inside the housing 8 of the feed pump 3, a pump 5 as an inscribed gear pump 6 or a trochoid pump 26 and a motor 4 are arranged. The pot-shaped housing 10 includes a notch 54. The electric motor 4 includes a stator 13 having a coil 14 as an electromagnet 15 and a soft iron core 45 as a soft magnetic core 32, and the soft iron core 45 is configured as a laminated steel plate 33. In the stator 13, a pump 5 as an internal gear pump 6 having an inner gear 22 having an internal ring gear 23 and an outer gear 24 having an external ring gear 25 are positioned. Therefore, the inner gear and the outer gears 22 and 24 constitute the gear 20 and the rotor 18, and the internal ring gear and the external ring gears 23 and 25 have a plurality of teeth 21 as the pressure feeding element 19. A work space 47 is formed between the inner gear 22 and the outer gear 24. Since the permanent magnet 17 is incorporated in the outer gear 24, the outer gear 24 also forms the rotor 16 of the electric motor 4. Therefore, the electric motor 4 is incorporated in the pump 5 or vice versa. Since the electromagnets 15 of the stator 13 are alternately supplied with power, the rotor 16 or the outer gear 24 is rotated about the rotation axis 27 or 27b based on the magnetic field generated in the electromagnet 15.

  The housing cover 9 is used as a bearing 11, a thrust bearing 11, or a sliding bearing 11 for the inner gear or outer gear 22, 24. An inflow passage 28 and an outflow passage 29 are formed in the housing cover 9. The fluid to be pumped, that is, fuel, flows into the feed pump 3 through the inflow passage 28, and the fuel flows out of the feed pump 3 again through the outflow passage 29. Each of the bowl-shaped housing 9 and the housing cover 10 has three holes 46, and screws (not shown) are screwed into the holes 46 so that the bowl-shaped housing 9 and the housing cover 10 are screwed together. In this case, the bowl-shaped housing 9 and the housing cover 10 are fluidly overlapped with each other with a seal (not shown).

  The internal gear pump 6 or the trochoid pump 26 has a work space 47. In this case, the work space 47 is divided into an inflow work space 30 as the suction side and an outflow work space 31 as the discharge side (FIG. 4). In the inflow work space 30, the work space 47 is expanded, and in the outflow work space 31, the work space 47, that is, the pressure feeding space between the plurality of teeth 21 of the inner gear and the outer gears 22 and 24 is reduced. In this case, the angle range of the inflow work space and the angle range of the outflow work space are each 180 °.

In the internal gear pump 6 shown in FIG. 4, unlike FIGS. 2 and 3, the inner gear 22 is driven instead of the outer gear 24, that is, the permanent magnet 17 is placed in the inner gear 22. Installed or incorporated, the inner gear 22 forms the rotor 16 of the electric motor 4. The inner gear and the outer gears 22 and 24 are driven in the rotation direction 34. The inner and outer gears 22 and 24 are eccentrically supported with an eccentricity e. In this case, the inner gear 22 performs a rotational motion about the rotational axis 27a, the outer gear 24 performs a rotational motion about the rotational axis 27b, and the two rotational axes 27a and 27b have an interval e. Have. The outer gear 24 has a radius of curvature R _az at the innermost position of the tooth tip 50, and has a radius of curvature R _am at the lowest position between the plurality of teeth 21. Therefore, the difference between R _az and R _am corresponds to the radial dimension of the teeth 21 of the outer gear 24. In FIG. 5, the tooth tip 50 is distinguished from the other teeth 21 by a horizontal parallel oblique line. Therefore, the tooth tip 50 of the tooth 21 of the outer gear 24 occupies the last approximately 30% of the radial dimension of the tooth 21 toward the rotation axis 27 b of the outer gear 24. In a similar manner, the row of teeth 21 of the inner gear 22 has a radius of curvature R _iz at the outermost position of the tooth tip 50 and a radius of curvature R _im at the lowest position between the plurality of teeth 21. Have.

FIG. 4 shows a cross-sectional view perpendicular to the rotation axes 27a and 27b. In this case, the teeth 21 of the outer gear 24 are formed outside as a segment of a circle having a center point M and a radius of curvature S (FIG. 5). In this case, K is an interval from M with respect to the rotation axis 27 b of the outer gear 24. The shape of the teeth 21 of the inner gear 22 is configured as a cycloid according to Non-Patent Document 1 in relation to the shape of the teeth 21 of the outer gear 24. In this case, the structure or mathematical calculations of the teeth 21 of the inner gear 22, the actual radius of curvature S and virtual radius of curvature S _f of the teeth 21 of the outer gear 24 and is used, the radius of curvature S _f The virtual It is larger than the actual curvature radius S. Therefore, the teeth 21 of the outer gear 24 actually have only the radius of curvature S indicated mainly by the solid line in FIG. The virtual curvature radius S _f and the transition area 53 are indicated by broken lines. The imaginary curvature radius S _f of the teeth 21 of the outer gear 24 protrudes outside the drive side surface 51 of the teeth 21 of the outer gear 24, and the imaginary curvature radius S _f becomes the curvature radius S in the continuous transition region 53. Be adapted. Therefore, the virtual curvature radius S _f exists on the tooth tip 50 and the free side surface 52. The driving side surface 51 has a curvature radius S. The shape of the teeth 21 of the inner gear 22 is the driving side 51, is constructed or calculated based on the radius of curvature S, the free side 52 and the tooth tip 50, is configured or calculated based on a virtual radius of curvature S _f . The transition region 53 also occurs on the teeth 21 of the inner gear 22. In FIG. 5, the actual teeth 21 of the inner gear 22 are shown by solid lines. The solid line in the drive side 51, have been created based on the actual radius of curvature S, the solid line in the addendum 50 and the free side 52, have been created based on the virtual radius of curvature S _f. The broken lines in the tooth tip 50 and the free side surface 52 of the tooth 21 of the inner gear 22 are created based on the actual curvature radius S. Accordingly, the transition region 53 occurs in the inner gear 22 in the actual line indicated by the solid line. Thus, in FIG. 5 there is a spacing or play between the teeth 21 of the outer gear 24 and the teeth 21 of the inner gear 22 not shown in FIG. As a result, a play or interval not shown in FIG. 4 is generated between the tooth 21 of the inner gear 22 and the tooth 21 of the outer gear 24 between the tooth tip 50 and the free side surface 52. In order to transmit torque from the inner gear 22 to the outer gear 24, contact between the teeth 21 of the inner gear 22 and the teeth 21 of the outer gear 24 occurs at the three contacts 40 only on the driving side surface 51. This is because the shape of the teeth 21 of the inner gear 22 on the drive side surface 51 is configured or calculated according to the actual radius of curvature S of the teeth 21 of the outer gear 24. In FIG. 4, only the contact 40 is shown, and based on the three-dimensional dimensions of the inner gear 22 and the outer gear 24 in a direction perpendicular to the projection plane, the contact 40 is an actual contact line. . Accordingly, in the pressure angle range α _K with the contact 40, there is substantially no leakage or fluid loss between the pressure-feeding spaces between the teeth 21 of the inner gear 22 and the teeth 21 of the outer gear 24. This is because the driving side surfaces 51 of the teeth 21 of the inner gear 22 and the outer gear 24 are under pressure based on torque transmission from the inner gear 22 to the outer gear 24. Preferably, the pressure angle range corresponds to the dimensions of the inflow passage 28 (not shown). Inlet passage 28 is present in the inlet passage angle range alpha _Z, the inflow passage angle range alpha _Z, starting from point 49 meshing with counter-clockwise direction, the ends of the inlet passage 28 in the region of the tooth tip point 48 since ends with an inlet passage angle range alpha _Z has an angle of about 170 °. The pressure angle range α _K with a plurality of contacts 40 again starts from the meshing point 49 in the counterclockwise direction and ends at the end of the three contacts 40, so the pressure angle range α _K is about 70 °. . The outflow passage 29 is in the outflow passage angle range α _A , and this outflow passage angle range α _A starts at the meshing point 49 in the clockwise direction, and therefore the outflow passage angle range α _A is an angle of about 170 °. have. Sealing angle range alpha _D is in the region of the tip point 48 between the inflow passage angle range alpha _Z and the outflow passage angle range alpha _A. Therefore, a large leakage loss occurs between the inflow passage 28 and the outflow passage 29 due to the large spacing or play between the plurality of teeth 21 in the region of the tooth tip 48.

  In another embodiment not shown, it is the outer gear 24 that is driven rather than the inner gear 22. Therefore, the contact 40 does not start from the meshing point 49 in the counterclockwise direction, but starts from the meshing point 49 in the clockwise direction. The drive side surface 51 is formed on the tooth 21 on the opposite side compared to the tooth 21 of FIGS. 4 and 5. Preferably, in this embodiment not shown, the pressure angle range corresponds to the dimension of the outflow passage 29 (not shown).

FIG. 5 shows another embodiment of the inscribed gear pump 6, and the following mainly describes differences from the embodiment shown in FIG. The inflow passage 28 is formed only in the region of the plurality of contacts 40, and four contacts 40 are provided. Of the four contacts 40, the contact 40 outside the inflow passage 28 has a seal angle. It exists in the range α _D and the outflow passage 29 is present only in the working space or spaces having a progressively smaller volume, i.e. in the tooth tip and meshing locations 48, 49, only on the right side in FIG. Instead, it partially exists also in one or a plurality of work spaces as the inflow work space 30 having a gradually increasing volume. Therefore, only two working spaces between the plurality of teeth 21 with a plurality of contacts 40 are used as working spaces for pumping fluid. As a result, substantially no leakage loss occurs between the inflow passage 28 and the outflow passage 29. This is because a contact 40 exists in the seal angle range α _D , that is, in the region between the inflow passage 28 and the outflow passage 29, and in this contact 40, an almost complete seal based on the contact is guaranteed. is there. Outside the pressure angle range α _K , the play or spacing between the teeth 21 in the pumping space having a volume that gradually increases in the counterclockwise direction toward the tooth tip 48 increases. In contrast to the embodiment of FIG. 5, if the inflow passage 28 is extended slightly beyond the last contact 40 towards the tip 48 and the outflow passage 29 is correspondingly shortened, slight leakage will occur. Generated and three working spaces between the teeth 21 are used to pump the fluid. In order to increase the discharge amount of the pump 5, it is preferable to increase the number of pumping spaces between a plurality of teeth with less leakage and pumping fluid.

  Overall, the inscribed gear pump 6 according to the invention offers significant advantages. Based on the play or spacing of the tooth tip 50 and the free side surface 52, the friction loss is very small, and increasing the number of contacts 40 results in a decrease in contact pressure and thus a decrease in wear at the contacts 40.

DESCRIPTION OF SYMBOLS 1 Pump apparatus 2 High pressure injection system 3 Electric feed pump 4 Electric motor 5 Pump 6 Internal gear pump 7 High pressure pump 8 Housing 9 Housing cover 10 Bowl-shaped housing 11 Bearing 13 Stator 15 Electromagnet 16 Rotor 17 Permanent magnet 18 Rotor 20 Gear 21 teeth 22 inner gear 23 internal gear ring gear 24 outer gear 25 outer gear ring gear 26 trochoid pumps 27, 27a, 27b rotation axis 28 inflow passage 29 outflow passage 30 inflow work space 31 outflow work space 32 soft magnetic core 35 fuel pipe 36 high pressure fuel Pipe 37 Fuel return pipe 38 Fuel filter 39 Internal combustion engine 40 Automobile 40 Contact point 41 Fuel tank 42 High pressure rail 43 Injector 44 Drive shaft 45 Soft iron core 47 Work space 48 Tooth point 49 meshing location 50 tooth tip 51 drive side 52 free side 53 transition region 54 notch K interval M center point S actual radius of curvature S _f virtual radius of curvature R _am , R _az , R _im , R _iz radius of curvature α _A outflow passage Angle range α _K Pressure angle range α _Z Inflow passage angle range α _D Seal angle range

Claims (14)

An internal gear pump (6) for pumping fluid,
An inner gear (22) having an internal ring gear (23);
An outer gear (24) with an external ring gear (25);
A plurality of teeth (21) of the inner gear and outer gear (22, 24) mesh with each other, and the inner gear (22) or the outer gear (24) is driven,
A work space (47) is formed between the inner gear (22) and the outer gear (24), and the work space (47) includes an inflow work space (30) and an outflow work space (31). Is divided into
An inflow passage (28) opened in the inflow work space (30) for introducing the fluid to be pumped into the inflow work space (30), and the outflow work space (31). And an outflow passage (29) that opens into the outflow work space (31).
The plurality of teeth (21) of the inner gear (22) and the plurality of teeth (21) of the outer gear (24) are respectively on the drive side surface (51) and the drive side surface (51). A free side surface (52), and the drive side surface (51) of the inner gear (22) and the drive side surface (51) of the outer gear (24) are driven gears (22, 24). In order to transmit torque to the non-driven gear (22, 24) from
In the form of
The shape of the drive side surface (51) of the inner gear and / or outer gear (22, 24) is such that at least two teeth (21) of the inner gear and outer gear (22, 24) overlap each other. At the tip (48), there is a gap or play between the plurality of teeth (21) of the inner gear (22) and the plurality of teeth (21) of the outer gear (24). An inscribed gear pump, characterized in that   The shape of the free side surface (52) of the inner gear and / or outer gear (22, 24) is such that a plurality of teeth (21) of the inner gear and outer gear (22, 24) are formed on the free side surface (52). The internal gear pump according to claim 1, wherein the internal gear pump is configured to have a gap or play.   The plurality of teeth (21) of the inner gear (22) and the plurality of teeth (21) of the outer gear (24) have tooth tips (50), and the inner gear and / or outer gear (22, The shape of the tooth tip (50) of 24) is such that the tooth tip (50) of the plurality of teeth (21) of the inner gear (22) is the plurality of teeth (21) of the outer gear (24), in particular. The tooth tips (50) and the tooth tips (21) of the plurality of teeth (21) of the outer gear (24) so as not to contact the free side surfaces (2) of the teeth (21) and / or 50) is configured such that it does not contact the plurality of teeth (21) of the inner gear (22), in particular the tip (50) and the free side surface (2) of the plurality of teeth (21). Claims 1 or 2 Internal gear pump described.   The tooth tips (50) of the plurality of teeth (21) of the inner gear and outer gear (22, 24) are on the rotation axes (27a, 27b) of the inner gear and outer gear (22, 24), respectively. Towards the last 30%, 20% or 10% of the radial dimension of the plurality of teeth (21) of the inner gear and outer gear (22, 24), preferably the drive side (51) and / or the free side surface (52) is formed outside the tooth tip (50) of the plurality of teeth (21) of the inner gear and outer gear (22, 24). The inscribed gear pump according to claim 3.   The plurality of inner gears and outer gears (22, 24) at the free side surface (52) of the plurality of teeth (21) and / or the tooth tip (48) of the plurality of teeth (21) of the inner gear and outer gear (22, 24). The spacing or play between the teeth (21) is at least 5 μm, 10 μm, 20 μm, 40 μm or 60 μm and / or less than 200 μm, 150 μm, 100 μm or 80 μm and / or between 10 μm and 150 μm 5. The internal gear pump according to claim 1, characterized in that it is between 20 μm and 100 μm.   The shape of the drive side surface (51) of the inner gear and / or outer gear (22, 24) is such that at least three, four or five teeth (21) of the inner gear and outer gear (22, 24) are mutually connected. The internal gear pump according to any one of claims 1 to 5, wherein the internal gear pump is configured to overlap each other.   The inscribed gear pump according to any one of claims 1 to 6, wherein the inscribed gear pump (6) is a trochoid pump (26).   The inscribed gear pump (6) has an electric motor (4) having a stator (13) and a rotor (16), and driven gears (22, 24) are the rotor (16). The inscribed gear pump according to claim 1, wherein the inscribed gear pump is formed by:   9. Inscribed type according to claim 8, characterized in that a permanent magnet (17) of the rotor (16) is mounted or incorporated in the driven gear (22, 24). Gear pump.   The inflow passage (28) is only partially opened in the inflow work space (30) having an expanding volume, and the outflow passage (29) is in the outflow work space (31) having a contracting volume. The internal gear pump according to any one or more of claims 1 to 9, characterized in that the internal gear pump is further open in the inflow work space (30). The inflow angle range is equal to or greater than the pressure angle range and the outflow angle range is greater than 180 °, so there are no contacts (40) in the seal angle range and all contacts (40 ) Exists in the inflow angle range, or
The inflow angle range is smaller than the pressure angle range and the outflow angle range is greater than 180 °, so that a contact (40) exists in the seal angle range.
The inscribed gear pump according to claim 10, wherein:   The outflow passage (29) is only partially open into the outflow work space (31) having a volume that is reduced, and the inflow passage (28) is within the inflow work space (31) having an increase volume. The internal gear pump according to any one or more of the preceding claims, characterized in that it opens into the outlet and further partially opens into the outflow work space (31). Since the outflow angle range is equal to or greater than the pressure angle range and the inflow angle range is greater than 180 °, there are no contacts (40) in the seal angle range, preferably all contacts (40) exists in the outflow angle range, or
Since the outflow angle range is smaller than the pressure angle range and the inflow angle range is greater than 180 °, a contact (40) exists in the seal angle range.
The inscribed gear pump according to claim 12, wherein A high pressure injection system (2) for an internal combustion engine (39), comprising:
A high-pressure pump (7);
A high-pressure rail (42);
Preferably an electric feed pump (3) for pumping fuel from a fuel tank (41) to the high pressure pump (7);
In the type having
High-pressure injection system (2) for an internal combustion engine (39), characterized in that the feed pump (3) is configured according to any one or more of claims 1 to 13.

Images