JP3752996B2 - Rotary pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary pump that sucks and discharges fluid, and is particularly suitable for an internal gear type or external gear type pump.
[0002]
[Prior art]
In the conventional internal gear type rotary pump, one central plate part is arranged between two side plate parts, and the inner rotor and outer rotor are eccentrically arranged in the space formed by these plate parts. Has been. In the inner rotor with outer teeth on the outer periphery and the outer rotor with inner teeth on the inner periphery, the inner teeth and outer teeth mesh with each other, and a plurality of gaps are formed by these teeth. Yes. If a line passing through both rotation center axes of the inner rotor and the outer rotor is a center line of the pump, suction ports and discharge ports communicating with the plurality of gaps are provided on both sides of the center line.
[0003]
FIG. 6 is a cross-sectional view showing a configuration of a portion that transmits the torque of the drive shaft to the inner rotor in the conventional rotary pump. The drive shaft 65 is inserted into the shaft hole 52b of the inner rotor 52, and the drive shaft A cylindrical pin 66 is inserted into the 65 key grooves 65 a and the key grooves 52 c of the inner rotor 52.
[0004]
The torque of the drive shaft 65 is transmitted to the inner rotor 52 through the pin 66, and the outer rotor (see FIG. (Not shown) also rotate in the same direction. At this time, while the outer rotor and the inner rotor 52 make one rotation, the volume of each gap portion changes to suck fluid from the suction port and discharge the fluid from the discharge port.
[0005]
Further, the shaft hole 52b is tapered at both ends in the axial direction as shown in FIG. 7 which is a cross-sectional view taken along the line II in FIG. 6 as a relief portion for preventing both ends of the shaft hole 52b from coming into contact with the drive shaft 65. A portion 52x is formed, or a counterbore portion 52y having a R-shaped cross section is formed as shown in FIG. 8, which is a view corresponding to the II cross section of FIG. Then, the radial positioning of the inner rotor 52 with respect to the drive shaft 65 is performed at the support portion 52z formed at the intermediate portion in the axial direction in the shaft hole 52b.
[0006]
[Problems to be solved by the invention]
However, when the torque of the drive shaft 65 is transmitted to the inner rotor 52, the pin 66 tilts due to the rattle between the key groove 65a of the drive shaft 65 and the pin 66, and therefore the inner rotor side key groove 52c The pin 66 does not come into contact with the side surface 52d, and the pin 66 comes into contact (point contact) only with the end portion (edge portion) 52f on the shaft hole 52b side in the key groove 52c.
[0007]
When the pin 66 comes into contact with the tapered portion 52x or the counterbore portion 52y at the end 52f on the shaft hole 52b side, the direction in which the inner rotor 52 is pressed against the side plate portion 71 as shown by the arrows in FIGS. The unbalanced load acts on the inner rotor 52. For this reason, the inner rotor 52 is pressed against the side plate portion 71 to be worn, and the gap between the inner rotor 52 and the side plate portion 71 is increased to increase the leakage amount of the discharged fluid. There was a problem of being lowered.
[0008]
The inner rotor 52 is always pushed from the high-pressure gap side to the low-pressure gap side, and the inner rotor 52 is obtained by the resultant force of the pressure pushing the inner rotor 52 due to the pressure difference of the gap and the above-described offset load. Is inclined with respect to the axis of the drive shaft 65. The inclination degree of the inner rotor 52 is greatest when the direction of the force pushing the inner rotor 52 due to the pressure difference in the gap is opposite to the direction of the force transmitted to the inner rotor 52 via the pin 66. It becomes the smallest when the direction of those forces is the same. That is, the inclination degree of the inner rotor 52 changes periodically with one rotation of the inner rotor 52 as one period.
[0009]
The amount of fluid leakage from the gap between the inner rotor 52 and the side plate portion 71 and the amount of fluid leakage from the gap between the inner tooth portion and the outer tooth portion are periodically changed according to the inclination degree of the inner rotor 52. The discharge pressure fluctuates (generation of pulse pressure) due to the change in the amount of fluid leakage, and there is a problem that sound and vibration are generated by the pulse pressure.
[0010]
Similarly, in an external gear-type rotary pump that includes a drive-side rotor and a driven-side rotor that both have outer teeth on the outer periphery, an unbalanced load is applied to the drive-side rotor to which the torque of the drive shaft is transmitted via a pin. There is a problem that the drive-side rotor is pressed against the side plate portion and is worn out, and the discharge amount is reduced. In addition, the degree of inclination of the drive-side rotor periodically changes due to the influence of the offset load, thereby causing a problem that a pulse pressure is generated and noise and vibration are generated.
[0011]
Furthermore, even in a rotary pump having only a rotor to which the torque of the drive shaft is transmitted via a pin (that is, not having the driven-side rotor described above), an uneven load acts on the rotor, and the rotor is a side plate portion. There is a problem in that they are worn out and worn out, and the discharge amount decreases. In addition, the degree of inclination of the rotor periodically changes due to the influence of the offset load, thereby causing a problem that a pulse pressure is generated and noise and vibration are generated.
[0012]
The present invention has been made in view of the above points, and in a rotary pump in which the torque of a drive shaft is transmitted to a rotor via a pin, a discharge amount is reduced by preventing an uneven load from acting on the rotor during torque transmission. The purpose is to prevent or suppress the generation of pulse pressure.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, the drive shaft (65), the outer teeth (52a) formed on the outer periphery, and the shaft hole (52b) into which the drive shaft (65) is inserted are provided. A rotor (52) having a drive shaft key groove (65a) formed on the drive shaft (65) and a pin (66) inserted into the rotor key groove (52c) formed on the rotor (52). 65) In the rotary pump in which the torque of 65) is transmitted to the rotor (52) via the pin (66), the rotor key groove (52c) is located more than the end (52f) on the shaft hole (52b) side of the rotor key groove (52c). On the bottom (52g) side of the pin, the pin (66) abuts on the rotor key groove (52c), and torque is transmitted.
[0014]
According to this, since the pin abuts on the rotor key groove on the bottom side of the end portion on the shaft hole side and torque is transmitted, the above-described offset load does not act on the rotor, and therefore the offset load is caused. It is possible to prevent or suppress a decrease in discharge amount and generation of pulse pressure.
[0015]
As in the second aspect of the present invention, the surface of the pin (66) that contacts the rotor key groove (52c) when torque is transmitted is defined as the pin contact surface (66a), and the pin contact surface ( 66a) and a radial line passing through the rotation center of the drive shaft (65) is defined as a reference line (G), and an offset amount from the pin contact surface (66a) to the reference line (G) is defined as L, When the width of the rotor key groove (52c) is W, by setting W ≧ 2L, the torque can be transmitted by bringing the pin into contact with the rotor key groove on the bottom side rather than the end on the shaft hole side.
[0016]
Further, as in the invention described in claim 3, the width of the rotor key groove (52c) is narrowed from the end (52f) on the shaft hole (52b) side toward the bottom (52g) side, thereby Torque can be transmitted by bringing the pin into contact with the rotor key groove on the bottom side from the end on the side.
[0017]
In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on embodiments shown in the drawings.
[0019]
(First embodiment)
FIG. 1 shows a schematic diagram of a brake pipe of a vehicle brake device to which a trochoid pump, which is one of internal gear pumps, is applied as a rotary pump. Hereinafter, the basic configuration of the brake device will be described with reference to FIG. In this example, in a front-wheel drive four-wheeled vehicle, an example in which the brake device according to the present invention is applied to a vehicle that constitutes a hydraulic circuit of X piping having piping systems of right front wheel-left rear wheel and left front wheel-right rear wheel. explain.
[0020]
As shown in FIG. 1, the brake pedal 1 is connected to a booster device 2, and the brake pedal force and the like are boosted by the booster device 2.
[0021]
The booster 2 has a push rod or the like that transmits the boosted pedaling force to the master cylinder 3, and the push rod presses a master piston disposed in the master cylinder 3, whereby the master cylinder Pressure is generated. The brake pedal 1, the booster 2, and the master cylinder 3 correspond to brake fluid pressure generating means.
[0022]
The master cylinder 3 is connected to a master reservoir 3 a that supplies brake fluid into the master cylinder 3 and stores excess brake fluid in the master cylinder 3.
[0023]
The master cylinder pressure is transmitted to the wheel cylinder 4 for the right front wheel FR and the wheel cylinder 5 for the left rear wheel RL via an antilock brake device (hereinafter referred to as ABS). The following description will be made on the right front wheel FR and the left rear wheel RL side, but the same applies to the left front wheel FL and the right rear wheel RR side which are the second piping system, and the description will be omitted.
[0024]
The brake device includes a pipe line (main pipe line) A connected to the master cylinder 3, and the pipe line A is provided with a control valve 40. The pipe A is divided into two parts by the control valve 40. That is, the pipe A is divided into a pipe A1 that receives the master cylinder pressure between the master cylinder 3 and the control valve 40, and a pipe A2 between the control valve 40 and the wheel cylinders 4 and 5.
[0025]
The control valve 40 is a two-position valve that is normally in communication. When the master cylinder pressure is lower than a predetermined pressure, the control valve 40 is shut off when the wheel cylinders 4 and 5 are suddenly braked or TRC. The differential pressure between the cylinder side and the wheel cylinder side is maintained.
[0026]
Further, in the pipeline A2, the pipeline A is branched into two, and one of the openings is provided with a pressure increase control valve 30 for controlling the increase of the brake fluid pressure to the wheel cylinder 4, and the other is provided. A pressure increase control valve 31 for controlling the increase in brake fluid pressure to the wheel cylinder 5 is provided.
[0027]
These pressure-increasing control valves 30 and 31 are configured as two-position valves that can control the communication / blocking state by an ABS electronic control unit (hereinafter referred to as ECU). When the two-position valve is controlled to be in communication, the master cylinder pressure or the brake fluid pressure generated by discharging the brake fluid from the pump can be applied to the wheel cylinders 4 and 5.
[0028]
Note that the first and second pressure-increasing control valves 30 and 31 are always controlled to communicate during normal braking when ABS control is not being executed. The pressure increase control valves 30 and 31 are provided with safety valves 30a and 31a, respectively, so that brake fluid is removed from the wheel cylinders 4 and 5 side when the brake depression is stopped and the ABS control is finished. It has become.
[0029]
Further, an ABS ECU is provided in a pipeline B connecting the pipeline A between the first and second pressure increase control valves 30, 31 and the wheel cylinders 4, 5 and the reservoir hole 20a of the reservoir 20. Depressurization control valves 32 and 33 that can control the communication / blocking state are respectively provided. These pressure reduction control valves 32 and 33 are always cut off in the normal brake state (when the ABS is not operating).
[0030]
A rotary pump 10 and a safety valve 10b are disposed in a pipe C connecting the control valve 40 of the pipe A, the pressure increase control valves 30 and 31, and the reservoir hole 20a of the reservoir 20. A motor 11 is connected to the rotary pump 10, and the rotary pump 10 is driven by the motor 11. A detailed description of the rotary pump 10 will be given later.
[0031]
In addition, a damper 12 is disposed on the discharge side of the rotary pump 10 in the pipe C in order to reduce the pulsation of the brake fluid discharged by the rotary pump 10. A pipe line (auxiliary pipe line) D is provided so as to connect between the reservoir 20 and the rotary pump 10 and the master cylinder 3, and the rotary pump 10 is connected to the pipe line via the pipe line D. The brake fluid of A1 is pumped up and discharged to the pipe A2, so that the wheel cylinder pressure in the wheel cylinders 4 and 5 is made higher than the master cylinder pressure to increase the wheel braking force. Note that the control valve 40 maintains a differential pressure between the master cylinder pressure and the wheel cylinder pressure at this time.
[0032]
The pipe D is provided with a control valve 34. The control valve 34 communicates when the brake is not operated, and is always cut off during normal braking.
[0033]
Next, the structure of the rotary pump 10 is demonstrated based on FIG. 2, FIG. 2 is a cross-sectional view showing the configuration of the rotary pump 10, and FIG. 3 is a cross-sectional view taken along the line EE in FIG.
[0034]
The rotary pump 10 includes a first pump 10A for the first piping system of the brake device and a second pump 10B for the second piping system. Since both pumps 10A and 10B have the same configuration, the first pump 10A will be described below, and the second pump 10B will be denoted by the same reference numerals in the same parts as the first pump 10A and the description thereof will be omitted.
[0035]
In the rotor chamber 50a of the casing 50 of the rotary pump 10, an outer rotor (driven rotor) 51 and an inner rotor (driving side rotor) 52 have respective rotation center axes (point X and point Y in the figure). Are assembled and stored in an eccentric state. The outer rotor 51 includes an inner tooth portion 51a on the inner periphery, and the inner rotor 52 includes an outer tooth portion 52a on the outer periphery. The outer rotor 51 and the inner rotor 52 are meshed with each other by forming a plurality of gap portions 53 by the tooth portions 51a and 52a.
[0036]
As can be seen from FIG. 2, the rotary pump 10 according to the present embodiment has a partition plate (crescents) in which a gap portion 53 is formed by the inner tooth portion 51 a of the outer rotor 51 and the outer tooth portion 52 a of the inner rotor 52. Multi-tooth trochoid type pump without). Further, in order to transmit the torque of the inner rotor 52 to the outer rotor 51, the inner rotor 52 and the outer rotor 51 have a plurality of contact points.
[0037]
A drive shaft 65 that is coupled to the motor 11 (see FIG. 1) and rotates in the direction of the arrow R is inserted into a shaft hole 52b formed through the central portion of the inner rotor 52. The drive shaft 65 One end of the pin 66 is inserted into the drive shaft key groove 65 a formed on the inner rotor 52, and the other end of the pin 66 is inserted into the rotor key groove 52 c formed on the inner rotor 52. Then, torque is transmitted from the drive shaft 65 to the inner rotor 52 via the pin 66, and the outer rotor 51 is also rotated in the same direction by the meshing of the outer tooth portion 52a and the inner tooth portion 51a as the inner rotor 52 rotates. To do.
[0038]
The outer rotor 51, the inner rotor 52, the drive shaft 65, and the pin 66 are made of SUJ2 (high carbon chrome bearing steel) and are tempered and tempered.
[0039]
As shown in FIG. 3, the casing 50 includes a first side plate portion 71 and a second side plate portion 72 arranged so as to sandwich both rotors 51 and 52 from both sides, and the first and second side plate portions 72 and 72. It is comprised between the side plate parts 71 and 72, and is comprised from the center plate part 73 in which the hole which accommodates the outer rotor 51 and the inner rotor 52 was provided, and the rotor chamber 50a is formed by these.
[0040]
A rotating part constituted by the outer rotor 51 and the inner rotor 52 is rotatably incorporated in the rotor chamber 50a, the outer rotor 51 rotates around the point X, and the inner rotor 52 rotates around the point Y. It will be.
[0041]
Furthermore, when a line passing through the point X and the point Y serving as the respective rotation axes of the outer rotor 51 and the inner rotor 52 is a center line Z of the rotary pump 10, the center line Z is sandwiched between the first side plate portions 71. On the left and right sides, a suction port 60 and a discharge port 61 communicating with the rotor chamber 50a are formed. The suction port 60 and the discharge port 61 are disposed at positions that communicate with the plurality of gaps 53. The brake fluid from the outside can be sucked into the gap 53 through the suction port 60 and the brake fluid in the gap 53 can be discharged to the outside through the discharge port 61.
[0042]
Of the plurality of gaps 53, the closed portion 53 a on the side with the largest volume and the closed portion 53 b on the side with the smallest volume do not communicate with either the suction port 60 or the discharge port 61. The closed portions 53a and 53b hold the differential pressure between the suction pressure at the suction port 60 and the discharge pressure at the discharge port 61.
[0043]
As shown in FIG. 3, the second pump 10B for the second piping system is formed by the second side plate portion 72, the third side plate portion 74, and the second central plate portion 75. Arranged in the rotor chamber. The two pumps 10A and 10B have the same configuration, but the second pump 10B is arranged by rotating the first pump 10A by 180 ° about the drive shaft 65.
[0044]
Next, the structure of the pin 66 and the key grooves 52c and 65a will be described with reference to FIG. FIG. 4 is an enlarged view of a portion F (around the engaging portion of the pin 66) in FIG.
[0045]
In FIG. 4, the pin 66 has a columnar shape, and more specifically, a cylindrical shape. The drive shaft keyway 65a has a hole shape, more specifically, a cylindrical hole shape.
[0046]
The rotor key groove 52c penetrates from the side surface on one end side in the axial direction of the inner rotor 52 to the side surface on the other end side, and the opposing first and second side surfaces 52d and 52e are end portions (edges) on the shaft hole 52b side. Part) 52f extends radially outward to the bottom 52g. Further, the first and second side surfaces 52d and 52e are parallel to each other, and are also parallel to the axis of the drive shaft 65 when the inner rotor 52 and the drive shaft 65 are assembled.
[0047]
Here, when torque is transmitted, a part of the outer peripheral surface of the pin 66 comes into contact with the first side surface 52d. The surface 66a of the pin 66 on the side in contact with the first side surface 52d is in contact with the pin. A surface. A radial line G that is parallel to the pin contact surface 66a and passes through the rotation center of the drive shaft 65 (common with the rotation center axis Y of the inner rotor 52) is used as a reference line, and the pin contact surface 66a. The offset amount from the reference line G to the reference line G (the length between the pin contact surface 66a and the reference line G in the direction perpendicular to the reference line G) is L.
[0048]
The width of the rotor key groove 52c (the length in the direction perpendicular to the reference line G between the first and second side surfaces 52d and 52e) W is set to satisfy W ≧ 2L.
[0049]
Although not shown, tapered portions 52x (see FIG. 7) or countersinks having an R-shaped cross section are provided at both ends in the axial direction of the shaft hole 52b of the inner rotor 52 as relief portions for preventing contact with the drive shaft 65. A portion 52y (see FIG. 8) is formed. Furthermore, a support portion 52z (see FIGS. 7 and 8) for positioning the inner rotor 52 in the radial direction with respect to the drive shaft 65 is formed in the axial direction intermediate portion of the shaft hole 52b.
[0050]
Next, the operation of the brake device and the rotary pump 10 configured as described above will be described.
[0051]
In the rotary pump 10, the inner rotor 52 rotates according to the rotation of the drive shaft 65 by driving the motor 11, and the outer rotor 51 also rotates in the same direction due to the meshing of the inner tooth portion 51 a and the outer tooth portion 52 a. To do. At this time, the volume of each gap portion 53 changes in size while the outer rotor 51 and the inner rotor 52 make one rotation, so that the brake fluid is sucked from the suction port 60 and is directed from the discharge port 61 toward the pipeline A2. Exhale brake fluid. The wheel cylinder pressure is increased by the discharged brake fluid.
[0052]
As described above, the rotary pump 10 can perform a basic pump operation in which the brake fluid is sucked from the suction port 60 and the brake fluid is discharged from the discharge port 61 as the rotors 51 and 52 rotate.
[0053]
During the pump operation, the pin contact surface 66a of the pin 66 is inclined by the inclination angle θ1 with respect to the radial center line H of the drive shaft keyway 65a due to the difference in diameter between the drive shaft keyway 65a and the pin 66. The pin 66 transmits the torque of the drive shaft 65 to the inner rotor 52 in such a tilted state.
[0054]
At this time, as in the conventional pump (see FIG. 6), when the relationship between the width W of the rotor key groove 52c and the offset amount L is W <2L, the rotor key groove 52c with respect to the radial center line H of the drive shaft key groove 65a. Since the inclination angle θ2 of the first side surface 52d is smaller than the inclination angle θ1 of the pin contact surface 66a, the pin 66 abuts only on the end 52f of the rotor key groove 52c, and the inner rotor 52 is moved to the side plate portion side. An offset load in the direction of pressing against the inner rotor 52 acts on the inner rotor 52.
[0055]
On the other hand, when W = 2L, the first side surface 52d of the rotor key groove 52c and the pin contact surface 66a are parallel (that is, θ1 = θ2), so the pin 66 is pinned from the end 52f of the rotor key groove 52c. 66 abuts against the first side surface 52d in the range up to the radial tip.
[0056]
Further, when W> 2L, the inclination angle θ2 of the first side surface 52d is larger than the inclination angle θ1 of the pin contact surface 66a, so the pin 66 does not contact the end 52f of the rotor key groove 52c, The pin 66 is in contact with the first side surface 52d at the tip end in the radial direction.
[0057]
In this embodiment, since W ≧ 2L, when the torque of the drive shaft 65 is transmitted to the inner rotor 52, the pin 66 is the first side surface 52d on the bottom 52g side of the end 52f of the rotor key groove 52c. Always abut.
[0058]
In this way, when the torque of the drive shaft 65 is transmitted to the inner rotor 52 with the pin 66 always in contact with the first side surface 52d, the unbalanced load in the direction of pressing the inner rotor 52 against the side plate portion side is the inner load. It does not act on the rotor 52.
[0059]
Therefore, in this embodiment, since an unbalanced load does not act on the inner rotor 52, the discharge amount is reduced due to wear of the inner rotor 52 and the side plate portion, and pulse pressure is generated due to a periodic change in the amount of liquid leakage from the gaps between the portions. Can be prevented or suppressed.
[0060]
(Second Embodiment)
Next, a second embodiment shown in FIG. 5 will be described. FIG. 5 is a cross-sectional view showing the configuration around the engaging portion of the pin 66.
[0061]
In the first embodiment, when the torque of the drive shaft 65 is transmitted to the inner rotor 52, the pin 66 is necessarily brought into contact with the first side surface 52d on the bottom 52g side of the end 52f of the rotor key groove 52c. W ≧ 2L, the present embodiment is different in that the rotor key groove 52c is provided with a gradient. Other points are the same as in the first embodiment.
[0062]
By the way, when W <2L, in the conventional pump (see FIG. 6), the pin 66 abuts only on the end 52f of the rotor key groove 52c, and between the first side surface 52d of the rotor key groove 52c and the pin abutment surface 66a. A gap with an angle α is generated.
[0063]
Therefore, in the present embodiment, as shown in FIG. 5, the rotor key groove 52c is inclined at an angle θ3 so that the width becomes narrower from the end 52f toward the bottom 52g. Here, if a line parallel to the radial center line J of the rotor key groove 52c and passing through the end 52f is defined as a reference line K, the angle θ3 is defined between the reference line K and the side surfaces 52d and 52e of the rotor key groove 52c. It is an angle to make.
[0064]
When the gradient angle θ3 is set to be equal to or greater than the clearance angle α (that is, θ3 ≧ α), the pin 66 is more than the end 52f of the rotor key groove 52c when the torque of the drive shaft 65 is transmitted to the inner rotor 52. It always comes into contact with the first side surface 52d on the bottom 52g side.
[0065]
Accordingly, the unbalanced load in the direction in which the inner rotor 52 is pressed against the side plate portion does not act on the inner rotor 52, and therefore, as in the first embodiment, it is possible to prevent or suppress a decrease in discharge amount and generation of pulse pressure. it can.
[0066]
(Other embodiments)
In the above embodiment, the example in which the rotary pump of the present invention is applied to the ABS actuator of the vehicle brake device has been described. However, the rotary pump of the present invention can also be applied to other applications.
[0067]
In the above embodiment, the internal gear type rotary pump is shown. However, the present invention is applicable to a rotary pump using an external gear type, and further to a rotary pump using only one rotor (gear). is there.
[0068]
In the above-described embodiment, the drive shaft keyway 65a has a hole shape, but the drive shaft keyway 65a may be a groove extending in the axial direction of the drive shaft 65.
[Brief description of the drawings]
FIG. 1 is a pipe configuration diagram of a brake device including a rotary pump according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a specific configuration of the rotary pump in FIG.
3 is a cross-sectional view taken along the line E-E in FIG. 2;
4 is an enlarged view of a portion F in FIG. 2. FIG.
FIG. 5 is a cross-sectional view showing a main part of a second embodiment of the present invention.
FIG. 6 is a cross-sectional view showing a main part of a conventional pump.
7 is a cross-sectional view taken along the line II of FIG.
FIG. 8 shows another example of a conventional pump, and is a view corresponding to the II cross section of FIG.
[Explanation of symbols]
52 ... Rotor, 52a ... External teeth, 52b ... Shaft hole, 52c ... Rotor keyway,
52f ... end, 52g ... bottom, 65 ... drive shaft, 66 ... pin,
65a: Drive shaft keyway.

Claims (6)

Formed on the drive shaft (65), a rotor (52) having an external tooth portion (52a) formed on the outer periphery and a shaft hole (52b) into which the drive shaft (65) is inserted, and the drive shaft (65). And a pin (66) inserted into the rotor key groove (52c) formed in the rotor (52), and the torque of the drive shaft (65) is passed through the pin (66). In the rotary pump transmitted to the rotor (52),
The pin (66) is connected to the rotor key groove (52c) on the bottom (52g) side of the rotor key groove (52c) from the end part (52f) on the shaft hole (52b) side of the rotor key groove (52c). A rotary pump, wherein the torque is transmitted in contact with the rotary pump. A surface of the pin (66) that comes into contact with the rotor key groove (52c) when the torque is transmitted is defined as a pin contact surface (66a).
A radial line parallel to the pin contact surface (66a) and passing through the rotation center of the drive shaft (65) is defined as a reference line (G).
The offset amount from the pin contact surface (66a) to the reference line (G) is L,
When the width of the rotor key groove (52c) is W,
The rotary pump according to claim 1, wherein W ≧ 2L. 2. The rotary type according to claim 1, wherein a width of the rotor key groove (52 c) is narrowed from an end (52 f) on the shaft hole (52 b) side toward the bottom (52 g) side. pump. The driven rotor (51) having a tooth portion (51a) meshing with an external tooth portion (52a) of the rotor (52) and rotating following the rotor (52) is provided. 4. The rotary pump according to any one of 3. The said driven side rotor (51) has the said tooth | gear part (51a) in an inner periphery, The said rotor (52) is arrange | positioned inside the said driven side rotor (51), The Claim 4 characterized by the above-mentioned. The described rotary pump. The shaft hole (52b) includes a support portion (52z) for positioning the rotor (52) in the radial direction with respect to the drive shaft (65), and a relief portion for preventing contact with the drive shaft (65). (52x, 52y). The rotary pump according to any one of claims 1 to 5.

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