JP6581773B2 - Pump device - Google Patents

Description

  The present invention relates to a pump device.

  For example, as shown in Patent Document 1, an internal gear pump in which a gear has a tooth profile using a trochoid curve is known.

JP 2011-17318 A

  In the internal gear pump as described above, a lubricant, such as oil, sent by the internal gear pump enters the gap between the internal teeth and the external teeth, so that the lubricant in the portion where the internal teeth and the external teeth mesh with each other. Function as. However, in the internal gear pump as described above, the gap between the internal teeth and the external teeth is narrow, and it is difficult to supply a sufficient amount of fluid to the gap between the internal teeth and the external teeth. Therefore, there is a problem that the friction torque when the inner teeth and the outer teeth mesh with each other increases, and the torque efficiency of the internal gear pump decreases.

  On the other hand, if the gap between the inner teeth and the outer teeth is increased, a sufficient amount of fluid is easily supplied between the inner teeth and the outer teeth, and the friction torque when the inner teeth and the outer teeth are engaged with each other is increased. Can be reduced. However, if the gap between the inner teeth and the outer teeth is large, the flow rate leaking from the gap increases. Therefore, there is a problem that the volumetric efficiency of the internal gear pump is lowered.

  As described above, in the internal gear pump as described above, it is difficult to achieve both torque efficiency and volumetric efficiency, and as a result, the overall pump efficiency, which is a value obtained by multiplying torque efficiency and volumetric efficiency, is improved. It was difficult to do.

  In view of the above problems, an aspect of the present invention aims to provide a pump apparatus having a structure capable of improving the overall pump efficiency.

One aspect of the pump device of the present invention includes a drive unit having a shaft centered on a central axis extending in the axial direction, an inner rotor attached to the shaft and having the central axis as a first rotation axis , An annular outer rotor surrounding the radially outer side of the inner rotor, and a second rotating shaft of the outer rotor that is different from the first rotating shaft , wherein the inner rotor has a plurality of first tooth portions And the outer rotor has a second gear portion that is composed of a plurality of second gear portions and meshes with the first gear portion, and the tooth profile of the first gear portion. And the tooth profile of the second gear portion is a trochoidal tooth profile, and when viewed in the axial direction, from the first line segment connecting the rotation shaft of the inner rotor and the tooth tip of the first tooth portion, Before being positioned on the drive side of the first line segment From the first distance L1 to the inflection point of the first tooth portion and the first line segment to the inflection point of the first tooth portion located on the non-driving side of the first line segment. The second tooth portion located on the drive side of the second line segment from the second line segment connecting the second distance L2 and the rotation axis of the outer rotor and the tooth bottom of the second tooth portion. And a fourth distance L4 from the second line segment to the inflection point of the second tooth portion located on the non-driving side of the second line segment. And L2 ≦ L1, and L4> L3 , L2 <L4, and L3> L1, and on the counter-drive side of the external tooth portion provided on the outer periphery of the inner rotor, And a first gap between the inner teeth provided on the inner circumference of the outer rotor, and a second gap other than the first gap is provided at a substantially constant interval. The first gap is larger than the distance, and has a coordinate system in a line segment direction connecting the first rotation axis and the second rotation axis. When the inflection point located on the driving side of the tooth tip of the inner rotor and the inflection point located on the non-driving side of the tooth tip of the outer rotor coincide with the coordinate position in the line segment direction with reference to the coordinates The inflection point located on the anti-driving side of the tooth tip of the inner rotor and the inflection point located on the driving side of the tooth tip of the outer rotor are in a state where the position of the coordinate in the line segment direction does not match, The first gap is provided between a tooth bottom adjacent to the tooth tip on the non-driving side of the inner rotor and a tooth tip adjacent to the tooth bottom on the driving side of the outer rotor, The second gap is the tooth tip on the drive side of the inner rotor. A tooth bottom adjacent, is provided between the tooth tip adjacent the tooth bottom of the non-driven side of the outer rotor.

One aspect of the pump device of the present invention includes a drive unit having a shaft centered on a central axis extending in the axial direction, an inner rotor attached to the shaft and having the central axis as a first rotation axis , An annular outer rotor surrounding the radially outer side of the inner rotor, and a second rotating shaft of the outer rotor that is different from the first rotating shaft , wherein the inner rotor has a plurality of first tooth portions And the outer rotor has a second gear portion that is composed of a plurality of second gear portions and meshes with the first gear portion, and the tooth profile of the first gear portion. And the tooth profile of the second gear portion is a trochoidal tooth profile, and when viewed in the axial direction, from the first line segment connecting the rotation shaft of the inner rotor and the tooth tip of the first tooth portion, Before being positioned on the drive side of the first line segment From the first distance L1 to the inflection point of the first tooth portion and the first line segment to the inflection point of the first tooth portion located on the non-driving side of the first line segment. The second tooth portion located on the drive side of the second line segment from the second line segment connecting the second distance L2 and the rotation axis of the outer rotor and the tooth bottom of the second tooth portion. And a fourth distance L4 from the second line segment to the inflection point of the second tooth portion located on the non-driving side of the second line segment. the, L2 <L1, and, L4 ≧ L3, L2 <L4 , and, L3> L1 was filled, in the non-driven side of the external tooth portion provided on an outer periphery of the inner rotor, and the outer teeth And a first gap between the inner teeth provided on the inner circumference of the outer rotor, and a second gap other than the first gap is provided at a substantially constant interval. The first gap is larger than the distance, and has a coordinate system in a line segment direction connecting the first rotation axis and the second rotation axis. When the inflection point located on the driving side of the tooth tip of the inner rotor and the inflection point located on the non-driving side of the tooth tip of the outer rotor coincide with the coordinate position in the line segment direction with reference to the coordinates The inflection point located on the anti-driving side of the tooth tip of the inner rotor and the inflection point located on the driving side of the tooth tip of the outer rotor are in a state where the position of the coordinate in the line segment direction does not match, The first gap is provided between a tooth bottom adjacent to the tooth tip on the non-driving side of the inner rotor and a tooth tip adjacent to the tooth bottom on the driving side of the outer rotor, The second gap is the tooth tip on the drive side of the inner rotor. A tooth bottom adjacent, is provided between the tooth tip adjacent the tooth bottom of the non-driven side of the outer rotor.

  According to one aspect of the present invention, a pump device having a structure capable of improving the overall pump efficiency is provided.

FIG. 1 is a cross-sectional view showing the pump device of the present embodiment. FIG. 2 is a bottom view showing the pump unit of the present embodiment. FIG. 3 is a bottom view showing a portion of the pump portion of the present embodiment. FIG. 4 is a bottom view showing a portion of the pump portion of the present embodiment.

  Hereinafter, a pump device according to an embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each structure easy to understand, the actual structure may be different from the scale, number, or the like in each structure.

  In the drawings, an XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is a direction parallel to the axial direction of the central axis J shown in FIG. The Y-axis direction is a direction parallel to the direction in which the rotation axis C1 of the inner rotor 31 and the rotation axis C2 of the outer rotor 32 shown in FIG. 2 are aligned, that is, the vertical direction in FIG. The X-axis direction is a direction orthogonal to both the Y-axis direction and the Z-axis direction, that is, the left-right direction in FIG.

In the following description, the positive side (+ Z side) in the Z-axis direction is referred to as “rear side”, and the negative side (−Z side) in the Z-axis direction is referred to as “front side”. The rear side and the front side are simply names used for explanation, and do not limit the actual positional relationship and direction. Unless otherwise specified, a direction parallel to the central axis J (Z-axis direction) is simply referred to as an “axial direction”, and a radial direction around the central axis J is simply referred to as a “radial direction”. circumferential direction around the, i.e., about the axis of the central axis J of (theta _Z direction) simply referred to as "circumferential direction".

  FIG. 1 is a cross-sectional view showing a pump device 1 of the present embodiment. FIG. 2 is a bottom view showing the pump unit 20 of the present embodiment. FIG. 3 is a bottom view showing a portion of the pump unit 20 of the present embodiment. 2 and 3 show a state in which the pump cover 42 is removed.

  In this specification, the bottom view means viewing from the front side (−Z side) toward the rear side (+ Z side). Further, in this specification, the bottom view means a view seen from the front side toward the rear side.

  The pump device 1 of this embodiment is an internal gear pump. As illustrated in FIG. 1, the pump device 1 includes a drive unit 10 and a pump unit 20. The drive unit 10 drives the pump unit 20. The pump unit 20 is driven by the driving unit 10 to send fluid. The fluid sent by the pump unit 20 is, for example, oil used in an automobile. Examples of oil used in automobiles include ATF (Automatic Transmission Fluid). Hereinafter, each part will be described in detail.

[Drive part]
The drive unit 10 includes a motor housing 16, a rotor 12, a stator 13, a rear bearing 14, and a front bearing 15.
The motor housing 16 has a bottomed cylindrical shape that opens to the front side (−Z side). A rear bearing holding portion 17 is provided at the bottom of the motor housing 16.

The rotor 12 has a shaft 11. That is, the drive unit 10 has a shaft 11. The shaft 11 is centered on a central axis J extending in the axial direction (Z-axis direction). Shaft 11 is rotatably supported around a central axis J (± θ _Z direction) by a rear bearing 14 and the front bearing 15.
The stator 13 surrounds the outer side of the rotor 12 in the radial direction. The stator 13 is fixed inside the motor housing 16.

The rear bearing 14 is disposed on the rear side (+ Z side) of the stator 13. The rear bearing 14 is held by a rear bearing holding portion 17 of the motor housing 16.
The front bearing 15 is disposed on the front side (−Z side) of the stator 13. The front bearing 15 is held by a front bearing holding portion 41b of the pump housing 40 described later.

[Pump part]
The pump unit 20 is provided on the front side (−Z side) of the drive unit 10. The pump unit 20 includes a pump housing (housing) 40, an inner rotor 31, and an outer rotor 32. That is, the pump device 1 includes an inner rotor 31, an outer rotor 32, and a pump housing 40.

(Inner rotor and outer rotor)
The inner rotor 31 is attached to the shaft 11. More specifically, the inner rotor 31 is fitted and fixed to an end portion on the front side (−Z side) of the shaft 11. Thus, the inner rotor 31 is rotated about the axis of the central axis J together with the shaft 11 (± θ _Z direction). That is, as shown in FIG. 2, the rotation axis C <b> 1 of the inner rotor 31 coincides with the central axis J. The inner rotor 31 rotates clockwise as viewed from the front side (−Z side).

  The inner rotor 31 has an external gear portion (first gear portion) 35. The external gear portion 35 is provided on the outer periphery of the inner rotor 31. The external gear portion 35 includes a plurality of external tooth portions (first tooth portions) 33. The plurality of external teeth 33 are provided at equal intervals along the circumferential direction around the rotation axis C1. In the example of FIG. 2, for example, seven external teeth 33 are provided.

  As shown in FIG. 1, a supported hole portion 31 b that is recessed on the rear side (+ Z side) is provided on the rotor front surface 31 a on the front side (−Z side) of the inner rotor 31. The bottom view shape of the supported hole portion 31b is a circular shape concentric with the rotation axis C1, as shown in FIG.

  The outer rotor 32 has an annular shape that surrounds the radially outer side of the inner rotor 31. The outer rotor 32 rotates around the rotation axis C2. Although illustration is omitted, the rotation axis C2 is an axis parallel to the central axis J. That is, the rotation axis C2 is an axis parallel to the rotation axis C1 of the inner rotor 31. The rotation axis C2 is located on the + Y side of the rotation axis C1 of the inner rotor 31. That is, the rotation axis C <b> 2 of the outer rotor 32 is different from the rotation axis C <b> 1 of the inner rotor 31. The outer rotor 32 rotates clockwise as viewed from the front side (−Z side).

  The outer rotor 32 has an internal gear portion (second gear portion) 36 that meshes with the external gear portion 35. The internal gear portion 36 is provided on the inner periphery of the outer rotor 32. The internal gear part 36 includes a plurality of internal tooth parts (second tooth parts) 34. The plurality of inner teeth 34 are provided at equal intervals along the circumferential direction around the rotation axis C <b> 2 of the outer rotor 32. One inner tooth portion 34 is provided more than the outer tooth portion 33. That is, for example, eight internal teeth 34 are provided in the example of FIG. The outer rotor 32 is rotated by a rotational driving force transmitted from the inner rotor 31 when the internal gear portion 36 and the external gear portion 35 are engaged with each other.

In the present specification, the circumferential direction around the rotation axis C <b> 1 of the inner rotor 31 is defined as the driving direction Din of the inner rotor 31. In the present specification, the circumferential direction around the rotation axis C <b> 2 of the outer rotor 32 is defined as the driving direction Dout of the outer rotor 32. Since the rotation axis C1 of the inner rotor 31 which coincides with the center axis J, the driving direction Din is the same as the circumferential direction around the center axis J (theta _Z direction).

In the present specification, as shown in FIG. 3, the side where the external teeth 33 in the driving direction Din proceeds (+ Din side, + theta _Z side), and the internal teeth 34 advances in the driving direction Dout side (+ Dout side ) Is called the drive side. In the present specification, the side opposite to the side where the external teeth 33 in the driving direction Din is advanced (-DIN side, - [theta] _Z side), and the internal teeth 34 advances in the driving direction Dout side opposite the side (- Dout side) is called the non-driving side.

  As shown in FIG. 2, the external gear portion 35 and the internal gear portion 36 mesh with each other on the −Y side of each gear portion. A space TS is provided between the external gear portion 35 and the internal gear portion 36. The space TS is a space composed of an external gear portion 35, an internal gear portion 36, and a wall portion of a pump chamber 44 described later. The space TS increases from the portion where the external gear portion 35 and the internal gear portion 36 are engaged to the drive side, and is opposite to the portion where the external gear portion 35 and the internal gear portion 36 are engaged (+ Y side). Is the largest. The space TS decreases from the opposite side to the drive side from the portion where the external gear portion 35 and the internal gear portion 36 are engaged, and is minimized at the portion where the external gear portion 35 and the internal gear portion 36 are engaged. .

  Next, the tooth profile of the external gear portion 35 in the inner rotor 31 and the tooth profile of the internal gear portion 36 in the outer rotor 32 will be described in detail.

  The tooth shape of the external gear portion 35 and the tooth shape of the internal gear portion 36 are trochoidal tooth shapes. That is, the external shape of the external gear portion 35 and the external shape of the internal gear portion 36 in the bottom view (XY view) are composed of trochoidal curves.

  As shown in FIG. 3, the tooth tip 33a of the external tooth portion 33 is determined at one point. The tooth bottom 33d of the external tooth portion 33 is a boundary between the external tooth portions 33 adjacent to each other in the driving direction Din. That is, the tooth bottom 33d between the external tooth portions 33 adjacent to each other in the driving direction Din is determined at one point.

  Here, the tooth tip 33a of the external tooth portion 33 is the point where the radial distance from the rotation axis C1 in the external tooth portion 33 is the largest. The tooth bottom 33d of the external tooth portion 33 is the point where the radial distance from the rotation axis C1 in the external tooth portion 33 is the smallest.

  In the present specification, the radial distance from the rotation axis means the distance from the rotation axis in the radial direction around the rotation axis.

  The external tooth portion 33 has inflection points 33b and 33c one by one on both sides in the driving direction Din of the tooth tip 33a. The inflection point 33b is located on the drive side (+ Din side) of the tooth tip 33a. The inflection point 33c is located on the counter drive side (−Din side) of the tooth tip 33a.

  In the present specification, the inflection point means that the position of the radius of curvature in the outline of the tooth portion is from the radially outer side centered on the rotation axis to the radially inner side with respect to the tooth portion outline, or This is a point that changes from the radially inner side to the radially outer side.

  The tooth tip 34a of the internal tooth portion 34 is determined at one point. The tooth bottom 34d of the inner tooth portion 34 is a boundary between the inner tooth portions 34 adjacent to each other in the driving direction Dout. That is, the tooth bottom 34d between the inner tooth portions 34 adjacent to each other in the driving direction Dout is determined at one point.

  Here, the tooth tip 34a of the internal tooth portion 34 is a point where the radial distance from the rotation axis C2 in the internal tooth portion 34 is the smallest. The tooth bottom 34d of the internal tooth portion 34 is the point where the radial distance from the rotation axis C2 in the internal tooth portion 34 is the largest.

  The internal tooth portion 34 has inflection points 34b and 34c one by one on both sides of the driving direction Dout of the tooth tip 34a. The inflection point 34b is located on the drive side (+ Dout side) of the tooth tip 34a. The inflection point 34c is located on the counter drive side (−Dout side) of the tooth tip 34a.

  When viewed in the axial direction (Z-axis direction), a line segment connecting the rotation axis C1 of the inner rotor 31 and the tooth tip 33a of the external tooth portion 33 is defined as a first line segment Lr1. When viewed in the axial direction, a line segment connecting the rotation axis C2 of the outer rotor 32 and the tooth bottom 34d of the internal tooth portion 34 is defined as a second line segment Lr2.

  A distance from the first line segment Lr1 to the inflection point 33b of the external tooth portion 33 located on the drive side (+ Din side) of the first line segment Lr1 is defined as a first distance L1. A distance from the first line segment Lr1 to the inflection point 33c of the external tooth portion 33 located on the non-driving side (−Din side) of the first line segment Lr1 is defined as a second distance L2.

  A distance from the second line segment Lr2 to the inflection point 34c of the internal tooth portion 34 located on the drive side (+ Dout side) of the second line segment Lr2 is defined as a third distance L3. A distance from the second line segment Lr2 to the inflection point 34b of the internal tooth portion 34 located on the non-driving side (−Dout side) of the second line segment Lr2 is defined as a fourth distance L4.

  In this specification, the distance from each line segment to the inflection point is the shortest distance among the distances between each line segment and the inflection point when viewed in the axial direction (Z-axis direction). That is, the distance from each line segment to the inflection point is a distance in a direction orthogonal to each line segment between each line segment and the inflection point when viewed in the axial direction.

  The second distance L2 is less than or equal to the first distance L1, and the fourth distance L4 is greater than the third distance L3. That is, the first distance L1, the second distance L2, the third distance L3, and the fourth distance L4 satisfy L2 ≦ L1 and L4> L3.

  In the present embodiment, for example, the second distance L2 is smaller than the first distance L1. That is, in the present embodiment, for example, the first distance L1 and the second distance L2 satisfy L2 <L1.

  As an example, in the present embodiment, the ratio of the second distance L2 to the first distance L1 is 0.92 or less. That is, in the present embodiment, for example, the first distance L1 and the second distance L2 satisfy L2 / L1 ≦ 0.92. When the first distance L1 and the second distance L2 satisfy such a relationship, the torque efficiency of the pump device 1 can be further improved. Note that L2 / L1 is greater than zero.

  As an example, in the present embodiment, the fourth distance L4 with respect to the third distance L3 is 1.09 or more. That is, in the present embodiment, for example, the third distance L3 and the fourth distance L4 satisfy L4 / L3 ≧ 1.09. Since the third distance L3 and the fourth distance L4 satisfy such a relationship, the torque efficiency of the pump device 1 can be further improved.

  In the present embodiment, for example, the third distance L3 is larger than the first distance L1. That is, in the present embodiment, for example, the first distance L1 and the third distance L3 satisfy L3> L1.

  As an example, the ratio of the third distance L3 to the first distance L1 is greater than 0 and equal to or less than 1.005. That is, the first distance L1 and the third distance L3 satisfy 0 <L3 / L1 ≦ 1.005. By satisfying such a relationship between the first distance L1 and the third distance L3, it is possible to suppress interference between the external gear portion 35 and the internal gear portion 36 while suppressing a decrease in volumetric efficiency. .

(Pump housing)
As shown in FIG. 1, the pump housing 40 includes a pump body 41 and a pump cover 42.
The pump body 41 is attached to the front side (−Z side) of the motor housing 16. The pump body 41 has a front bearing holding portion 41b. The front bearing holding portion 41b is located at the end of the pump body 41 on the rear side (+ Z side).

  The body front surface 41a on the front side (−Z side) of the pump body 41 is provided with a recess 45a that is recessed on the rear side (+ Z side). The bottom view shape of the recess 45a is, for example, a circular shape concentric with the rotation axis C2 of the outer rotor 32, as shown in FIG.

  As shown in FIG. 1, a through hole 45 b that penetrates the pump body 41 in the axial direction (Z-axis direction) is provided on the bottom surface of the recess 45 a. The through hole 45b has, for example, a circular shape concentric with the central axis J. A part of the shaft 11 is inserted inside the through hole 45b in the radial direction.

  As shown in FIG. 2, the pump body 41 is provided with a suction port 46 and a discharge port 47. The suction port 46 and the discharge port 47 are open to the space TS. The suction port 46 is provided on the side (−X side) where the space TS increases as it advances toward the driving side. The discharge port 47 is provided on the side where the space TS becomes smaller (+ X side) as it goes to the drive side.

  As shown in FIG. 1, the pump cover 42 is attached to the front side (−Z side) of the pump body 41. The pump cover 42 closes the opening of the recess 45 a of the pump body 41. The pump cover 42 includes a cover main body 43a and a support portion 43b.

  A cover rear surface 43 c on the rear side (+ Z side) of the cover main body 43 a is in contact with the body front surface 41 a of the pump body 41. The support portion 43b protrudes rearward from the cover rear surface 43c of the cover main body 43a. The support portion 43 b is inserted into the supported hole portion 31 b of the inner rotor 31. Thereby, the inner rotor 31 is supported by the support part 43b. Therefore, the inner rotor 31 can be prevented from tilting.

  A pump chamber 44 is configured by the inner surface of the recess 45 a of the pump body 41 and the cover rear surface 43 c of the cover body 43 a in the pump cover 42. That is, the pump housing 40 has a pump chamber 44. The pump chamber 44 accommodates the inner rotor 31 and the outer rotor 32.

  When the inner rotor 31 is rotated through the shaft 11 of the driving unit 10, the outer rotor 32 is rotated in conjunction with the inner rotor 31. Thereby, the space TS moves in the driving direction while changing the size. On the −X side, the space TS is increased, and the fluid sent by the pump device 1 is sucked into the space TS through the suction port 46. The sucked fluid is sent in the driving direction in the pump chamber 44 by the space TS. The fluid in the space TS is discharged from the space TS through the discharge port 47 as the space TS becomes smaller. In this way, the pump device 1 sends the fluid.

  According to the present embodiment, since the first distance L1 to the fourth distance L4 satisfy L2 ≦ L1 and L4> L3, it is possible to suppress the reduction in volumetric efficiency of the pump device, and Torque efficiency can be improved. This will be described in detail below.

  FIG. 4 is a bottom view showing a portion of the pump unit 20. FIG. 4 shows a portion where the outer tooth portion 33 and the inner tooth portion 34 are engaged with each other. In FIG. 4, the first line segment Lr1 and the second line segment Lr2 are both parallel to and overlapping the direction in which the rotation axes C1 and C2 are arranged (Y-axis direction).

  As shown in FIG. 4, when the second distance L2 is equal to or less than the first distance L1 and the fourth distance L4 is larger than the third distance L3, the non-drive side ( -Din side), the dimension L5 of the gap Ga between the outer tooth portion 33 and the inner tooth portion 34 is increased. Therefore, the fluid sent by the pump device 1 easily enters the gap Ga. The fluid that has entered the gap Ga covers the surfaces of the outer tooth portion 33 and the inner tooth portion 34 that are next engaged with each other. Thereby, the external tooth part 33 and the internal tooth part 34 contact via a fluid, and the friction torque between the external tooth part 33 and the internal tooth part 34 can be reduced. Therefore, according to the present embodiment, the torque efficiency of the pump device 1 can be improved.

  The dimension L5 of the gap Ga is the dimension of the gap Ga in a direction (X-axis direction) orthogonal to the direction in which the rotation axis C1 and the rotation axis C2 are aligned and orthogonal to the central axis J.

  In addition, according to the present embodiment, among the gaps between the outer teeth portion 33 and the inner teeth portion 34, the gaps other than the gap Ga on the non-driving side are set to a substantially constant narrow interval, thereby reducing the flow rate leaking from the gap. it can. Therefore, according to this embodiment, it can suppress that the volumetric efficiency of the pump apparatus 1 falls.

  As described above, according to the present embodiment, it is possible to improve the torque efficiency of the pump device 1 while suppressing a decrease in the volumetric efficiency of the pump device 1. Here, the total pump efficiency of the pump device 1 is a value obtained by multiplying the torque efficiency and the volumetric efficiency. Therefore, according to this embodiment, the pump apparatus which has a structure which can improve the pump whole efficiency is obtained.

  Further, according to the present embodiment, the first distance L1 and the second distance L2 satisfy L2 <L1, and thus the dimension L5 of the gap Ga can be further increased. As a result, the amount of fluid entering the gap Ga can be increased, and the friction torque between the outer tooth portion 33 and the inner tooth portion 34 can be further reduced. Therefore, according to this embodiment, the torque efficiency of the pump device 1 can be further improved, and as a result, the overall pump efficiency can be further improved.

  Further, according to the present embodiment, since the first distance L1 and the third distance L3 satisfy L3> L1, when the external tooth portion 33 and the internal tooth portion 34 are engaged, the external tooth portion 33 is It is easy to enter between the inner teeth 34. Thereby, it can suppress that the external tooth part 33 and the internal tooth part 34 mutually interfere.

  Further, according to the present embodiment, the rotation axis C <b> 2 of the outer rotor 32 is different from the rotation axis C <b> 1 of the inner rotor 31. Therefore, the size of the space TS between the inner rotor 31 and the outer rotor 32 can be changed along the driving direction. Thereby, by accommodating the fluid in the space TS between the inner rotor 31 and the outer rotor 32, the fluid can be sent from the suction port 46 to the discharge port 47.

  Further, according to the present embodiment, the pump housing 40 having the pump chamber 44 is provided. Therefore, a space TS for sending fluid can be configured by the wall portion of the pump chamber 44, the external gear portion 35, and the internal gear portion 36.

  In the present embodiment, the following configuration may be employed.

In the present embodiment, the first distance L1 and the second distance L2 may be the same.
In the present embodiment, the first distance L1 and the third distance L3 may be the same.

  In the present embodiment, a configuration in which the second distance L2 is smaller than the first distance L1 and the fourth distance L4 is not less than the third distance L3 may be employed. That is, in the present embodiment, the first distance L1, the second distance L2, the third distance L3, and the fourth distance L4 satisfy L2 <L1 and L4 ≧ L3. Also good. In this configuration, the third distance L3 and the fourth distance L4 may be the same.

  According to this configuration, similarly to the configuration satisfying L2 ≦ L1 and L4> L3 described above, the dimension L5 of the gap Ga can be increased, so that a pump device having a structure capable of improving the overall pump efficiency is obtained.

  The effects of the present embodiment were verified by comparing Examples 1 to 3 of the above-described embodiment with Comparative Examples 1 and 2. In each example and each comparative example, the fluid sent by the pump device was ATF. The temperature of ATF was 120 ° C. The discharge pressure of the fluid discharged from the pump chamber was 0.2 MPa. The flow rate discharged from the pump chamber was 2 L / min.

  The configuration of the pump unit in Examples 1 to 3 and Comparative Examples 1 and 2 was the same as the configuration of the pump unit 20 shown in FIG. 2 except for the first distance L1 to the fourth distance L4. The first distance L1 to the fourth distance L4 in the pump section are as shown in Table 1.

  In Table 1, the dimension L5 of the gap Ga is also described. The second distance L2, the third distance L3, the fourth distance L4, and the dimension L5 of the gap Ga are shown as a ratio when the first distance L1 is 1.

The pump part of Example 1 satisfies L2 <L1 and L4> L3.
The pump part of Example 2 satisfies L2 = L1 and L4> L3.
The pump part of Example 3 satisfies L2 <L1 and L4 = L3.

The pump unit of Comparative Example 1 satisfies L2 = L1 and L4 = L3.
The pump unit of Comparative Example 2 satisfies L2> L1 and L4> L3.
The pump parts of Examples 1 to 3 and Comparative Examples 1 and 2 satisfy L3> L1.

  For Example 1 to Example 3 and Comparative Examples 1 and 2, the discharge amount discharged from the pump chamber and the drive torque of the drive unit were measured, respectively, and the volumetric efficiency [%], torque efficiency [%], and pump Total efficiency [%] was calculated. The results are shown in Table 1 above.

  As shown in Table 1, in Examples 1 to 3, it was confirmed that the overall pump efficiency can be improved compared to Comparative Examples 1 and 2. When Example 1 was compared with Example 2 and Example 3, it was confirmed that the torque efficiency and total pump efficiency of Example 1 were higher than those of Example 2 and Example 3. Thus, it was confirmed that the torque efficiency and the overall pump efficiency can be further improved when the first distance L1 to the fourth distance L4 satisfy L2 <L1 and L4> L3.

  Further, Example 1, Example 2, and Comparative Example 2 have the same value for each distance except for the second distance L2. Example 1 and Example 2 have higher torque efficiency and pump efficiency than Comparative Example 2. Further, the torque efficiency and the pump efficiency of the first embodiment are larger than those of the second embodiment. In Example 1, L2 / L1 is 0.915. In Example 2, L2 / L1 is 1. In Comparative Example 2, L2 / L1 is 1.097. Thereby, it was confirmed that the first distance L1 and the second distance L2 satisfy L2 / L1 ≦ 0.92, whereby the torque efficiency can be further improved and the overall pump efficiency can be further improved.

  Further, Example 2 and Comparative Example 1 are the same except that the fourth distance L4 is different. In Example 2, the torque efficiency and the total pump efficiency are larger than those in Comparative Example 1. In Example 2, L4 / L3 is about 1.096. In Comparative Example 1, L4 / L3 is 1. Thereby, it was confirmed that the third distance L3 and the fourth distance L4 satisfy L4 / L3 ≧ 1.09, whereby the torque efficiency can be further improved and the overall pump efficiency can be further improved.

  DESCRIPTION OF SYMBOLS 1 ... Pump apparatus, 10 ... Drive part, 11 ... Shaft, 12 ... Rotor, 31 ... Inner rotor, 32 ... Outer rotor, 33 ... Tooth part, 33a, 34a ... Tooth tip, 33b, 33c, 34b, 34c ... Inflection Point, 33d, 34d ... tooth bottom, 33 ... external tooth portion (first tooth portion), 34 ... internal tooth portion (second tooth portion), 35 ... external gear portion (first gear portion), 36 ... Internal gear part (second gear part), 40 ... Pump housing (housing), 44 ... Pump chamber, J ... Central axis, C1, C2 ... Rotating shaft, L1 ... First distance, L2 ... Second Distance, L3 ... third distance, L4 ... fourth distance, Lr1 ... first line segment, Lr2 ... second line segment

Claims (6)

A drive unit having a shaft centered on a central axis extending in the axial direction;
An inner rotor attached to the shaft and having the central axis as a first rotation axis ;
An annular outer rotor surrounding the radially outer side of the inner rotor, and a second rotating shaft of the outer rotor different from the first rotating shaft;
With
The inner rotor has a first gear portion composed of a plurality of first tooth portions,
The outer rotor has a second gear portion that includes a plurality of second tooth portions and meshes with the first gear portion,
The tooth profile of the first gear part and the tooth profile of the second gear part are trochoidal tooth profiles,
When viewed in the axial direction,
The first line segment connecting the rotation axis of the inner rotor and the tooth tip of the first tooth portion to the inflection point of the first tooth portion located on the drive side of the first line segment. A distance L1 of 1;
A second distance L2 from the first line segment to the inflection point of the first tooth portion located on the non-driving side of the first line segment;
The second line segment connecting the rotation axis of the outer rotor and the root of the second tooth portion to the inflection point of the second tooth portion located on the drive side of the second line segment. A distance L3 of 3;
The fourth distance L4 from the second line segment to the inflection point of the second tooth portion located on the non-driving side of the second line segment is:
L2 ≦ L1 and L4> L3 , L2 <L4 and L3> L1 are satisfied,
On the counter-drive side of the outer tooth portion provided on the outer periphery of the inner rotor, a first gap is provided between the outer tooth portion and the inner tooth portion provided on the inner periphery of the outer rotor. And
The second gap other than the first gap is a substantially constant interval, and the dimension of the first gap is larger than the interval,
Having a coordinate system in the direction of the line segment connecting the first rotation axis and the second rotation axis;
The coordinates in the line segment direction of the inflection point located on the drive side of the tooth tip of the inner rotor and the inflection point located on the non-drive side of the tooth tip of the outer rotor on the basis of the coordinates of the first rotation axis The inflection point located on the anti-driving side of the tooth tip of the inner rotor and the inflection point located on the driving side of the tooth tip of the outer rotor are in the position of the coordinates in the line segment direction. It does n’t match,
The first gap is provided between a tooth bottom adjacent to the tooth tip on the non-driving side of the inner rotor and a tooth tip adjacent to the tooth bottom on the driving side of the outer rotor,
The second gap is a pump device provided between a tooth bottom adjacent to the tooth tip on the drive side of the inner rotor and a tooth tip adjacent to the tooth bottom on the non-drive side of the outer rotor . A drive unit having a shaft centered on a central axis extending in the axial direction;
An inner rotor attached to the shaft and having the central axis as a first rotation axis ;
An annular outer rotor surrounding the radially outer side of the inner rotor, and a second rotating shaft of the outer rotor different from the first rotating shaft;
With
The inner rotor has a first gear portion composed of a plurality of first tooth portions,
The outer rotor has a second gear portion that includes a plurality of second tooth portions and meshes with the first gear portion,
The tooth profile of the first gear part and the tooth profile of the second gear part are trochoidal tooth profiles,
When viewed in the axial direction,
The first line segment connecting the rotation axis of the inner rotor and the tooth tip of the first tooth portion to the inflection point of the first tooth portion located on the drive side of the first line segment. A distance L1 of 1;
A second distance L2 from the first line segment to the inflection point of the first tooth portion located on the non-driving side of the first line segment;
The second line segment connecting the rotation axis of the outer rotor and the root of the second tooth portion to the inflection point of the second tooth portion located on the drive side of the second line segment. A distance L3 of 3;
The fourth distance L4 from the second line segment to the inflection point of the second tooth portion located on the non-driving side of the second line segment is:
L2 <L1 and L4 ≧ L3 , L2 <L4 and L3> L1 are satisfied,
On the counter-drive side of the outer tooth portion provided on the outer periphery of the inner rotor, a first gap is provided between the outer tooth portion and the inner tooth portion provided on the inner periphery of the outer rotor. And
The second gap other than the first gap is a substantially constant interval, and the dimension of the first gap is larger than the interval,
Having a coordinate system in the direction of the line segment connecting the first rotation axis and the second rotation axis;
The coordinates in the line segment direction of the inflection point located on the drive side of the tooth tip of the inner rotor and the inflection point located on the non-drive side of the tooth tip of the outer rotor on the basis of the coordinates of the first rotation axis The inflection point located on the anti-driving side of the tooth tip of the inner rotor and the inflection point located on the driving side of the tooth tip of the outer rotor are in the position of the coordinates in the line segment direction. It does n’t match,
The first gap is provided between a tooth bottom adjacent to the tooth tip on the non-driving side of the inner rotor and a tooth tip adjacent to the tooth bottom on the driving side of the outer rotor,
The second gap is a pump device provided between a tooth bottom adjacent to the tooth tip on the drive side of the inner rotor and a tooth tip adjacent to the tooth bottom on the non-drive side of the outer rotor . The pump device according to claim 1, wherein the first distance L1 and the second distance L2 satisfy L2 <L1. 4. The pump device according to claim 1, wherein the first distance L1 and the second distance L2 satisfy L2 / L1 ≦ 0.92. 5. 5. The pump device according to claim 1, wherein the third distance L3 and the fourth distance L4 satisfy L4 / L3 ≧ 1.09. The pump device according to any one of claims 1 to 5 , further comprising a housing having a pump chamber that houses the inner rotor and the outer rotor.

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