JP2015052280A - Oil pump rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve problems that pump efficiency is deteriorated by oil leakage from a delivery side to a suction side through an inter-tooth gap of a pump rotor, and collision noise is generated in collision of the pump rotor.SOLUTION: An inner rotor 12A and an outer rotor 12B are made of a soft magnetic body, a tooth tip 12Aa and a tooth bottom 12Ab of an external tooth of the inner rotor 12A, and a tooth tip 12Ba and a tooth bottom 12Bb of an internal tooth of the outer rotor 12B are respectively magnetized in the radial direction, and the tooth tip 12Aa of the external tooth of the inner rotor 12A and the tooth tip 12Ba of the internal tooth of the outer rotor 12B are magnetized to the same pole, and the tooth bottom 12Ab of the external tooth of the inner rotor 12A and the tooth bottom 12Bb of the internal tooth of the outer rotor 12B are magnetized to the same pole.

Description

  The present invention relates to a rotor for an inscribed gear pump.

  2. Description of the Related Art Conventionally, an internal gear type oil pump is known as a pump used in an automobile hydraulic circuit or the like. As an example, a trochoid pump is shown in FIG.

  The pump body 11 of the trochoid pump 10 is formed by a pump head cover 11A and a pump body 11B, and a circular pump rotor housing hole 15 is formed in the pump body 11B. The pump rotor housing hole 15 houses an inscribed gear type pump rotor 12, and the pump rotor 12 is constituted by an inner rotor 12A and an outer rotor 12B.

  The outer rotor 12 </ b> B is formed in a columnar shape and is rotatably accommodated in the pump rotor accommodation hole 15. The outer rotor 12B is formed with an inner rotor storage chamber 16 for storing the inner rotor 12A. The inner rotor storage chamber 16 has star-shaped inner teeth.

  The inner rotor 12 </ b> A also has star-shaped outer teeth and is rotatably accommodated in the inner rotor storage chamber 16. A drive shaft 14 is connected to the inner rotor 12 </ b> A and is configured to be rotated by the drive shaft 14.

  The number of inner teeth of the inner rotor storage chamber 16 is set to be larger than the number of outer teeth of the inner rotor 12A. Accordingly, when the inner rotor 12A is rotated together with the outer rotor 12B by the drive shaft 14, the volume of the space formed between the inner rotor 12A and the outer rotor 12B is changed according to the rotation angle as shown in FIG. The oil is sucked from the suction port 17 by using this volume change, and is configured to be discharged from the discharge port 18.

  In this trochoid pump, the outer teeth of the inner rotor 12A and the inner teeth of the inner rotor storage chamber 16 of the outer rotor are engaged with each other and rotate while sliding. Therefore, as shown in FIG. 19 exists.

JP 2012-167621 A

  However, the conventional trochoid pump has a problem that oil leakage from the discharge side to the suction side occurs due to the gap, resulting in a decrease in pump efficiency.

  In addition, when mounted on a vibrating place such as in-vehicle use, there is a problem that a collision sound is generated based on an impact at the time of a collision between the inner rotor and the outer rotor.

The present invention has been made to solve such problems, and provides an oil pump that suppresses oil leakage in the interdental gap and suppresses the impulsive noise of the pump rotor, with almost the same components. Objective.

  In order to achieve the above object, the present invention according to claim 1 includes a pump body 11B having a cylindrical concave pump rotor housing hole 15 having a center axis at a position eccentric to the drive shaft 14, and an annular shape. The outer rotor 12B is formed and is rotatably accommodated in the cylindrical concave pump rotor accommodating hole 15, and has an outer rotor 12B having inner teeth in the inner rotor accommodating chamber 16, and outer teeth meshing with the inner teeth of the outer rotor 12B. The inner rotor 12A disposed on the drive shaft 14, the pump head cover 11A that closes the pump rotor housing hole 15 to form a pump rotor housing portion, and at least one of the pump body 11B and the pump head cover 11A are formed. In an internal gear type trochoid pump 10 having a suction port 17 and a discharge port 18, an inner rotor 12A and The outer rotor 12B is made of a soft magnetic material, and the outer teeth 12Aa and the teeth bottom 12Ab of the inner rotor 12A, the inner teeth 12Ba and the teeth 12Bb of the outer rotor 12B are magnetized in the radial direction, and The outer teeth 12Aa of the inner rotor 12A and the inner teeth 12Ba of the inner teeth of the outer rotor 12B are magnetized to the same polarity, and the outer teeth 12Ab of the inner rotor 12A and the inner teeth 12Bb of the outer rotor 12B are The oil pump rotor is characterized by being magnetized to the same polarity.

  According to the second aspect of the present invention, the magnetic poles of the outer tooth tip 12Aa and the tooth bottom 12Ab of the inner rotor 12A and the inner tooth tip 12Ba and the tooth bottom 12Bb of the outer rotor 12B are respectively magnetized in the radial direction. The oil pump rotor according to claim 1, wherein the oil pump rotor is magnetized to have different polarities at the end portions in the thrust direction.

  The present invention according to claim 3 is the oil pump rotor according to claim 1 or 2, wherein the inner rotor 12A and the outer rotor 12B are made of a magnetic material.

  The present invention according to claim 4 is characterized in that a magnetic material is embedded in each of the outer teeth 12Aa of the inner rotor 12A and the inner teeth 12Ba of the outer rotor 12B. In the oil pump rotor.

  According to the present invention, oil leakage between the suction side and the discharge side in the interdental gap can be reduced, and the pump efficiency can be improved.

  In addition, it is possible to suppress a collision sound that is generated based on an impact at the time of a collision between the inner rotor and the outer rotor.

(A) Exploded perspective view of oil pump in embodiment 1 of the present invention (b) Rotor plan view showing magnetization arrangement in embodiment 1 of the present invention (c) Enlarged view of rotor in embodiment 1 of the present invention ( d) Enlarged view of conventional rotor The perspective sectional view of the trochoid pump in Embodiment 2 of the present invention Plan view of a pump rotor in Embodiment 4 of the present invention

  Hereinafter, the details of the embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
An internal gear type oil pump is provided in, for example, an automatic transmission mounted on a vehicle, and supplies hydraulic oil or lubricating oil to a hydraulic control device of the automatic transmission.

  Fig.1 (a) shows the structure of the trochoid pump 10 in Embodiment 1 of this invention as a disassembled perspective view. In the following embodiments, a trochoid pump will be described as an example of an internal gear type oil pump.

  As shown in FIG. 1A, the trochoid pump 10 includes a pump head cover 11A and a pump body 11B. A circular pump rotor storage hole 15 is formed in the pump body 11, and the pump rotor storage hole 15 is formed. The pump rotor 12 is housed inside.

  The pump rotor 12 is composed of an inscribed gear type trochoid gear, and is composed of an inner rotor 12A that is a normal drive gear and an outer rotor 12B that is a driven gear. The outer rotor 12 </ b> B is formed in a columnar shape and is rotatably accommodated in the pump rotor accommodation hole 15. The outer rotor 12B is formed with an inner rotor storage chamber 16 for storing the inner rotor 12A. The inner rotor storage chamber 16 has star-shaped inner teeth. The inner rotor 12 </ b> A also has star-shaped outer teeth and is rotatably accommodated in the inner rotor storage chamber 16.

  A drive shaft 14 is connected to the central portion of the inner rotor 12A serving as a drive gear, and is configured to transmit drive torque from a power source such as an electric motor and to be rotated.

  Further, an oil seal 13 for preventing oil leakage is inserted between the drive shaft 14 and the pump body 11B.

  The number of inner teeth of the inner rotor storage chamber 16 is set to be larger than the number of outer teeth of the inner rotor 12A. Accordingly, when the inner rotor 12A is rotated together with the outer rotor 12B by the drive shaft 14, the volume of the space formed between the inner rotor 12A and the outer rotor 12B is changed according to the rotation angle as shown in FIG. The oil is sucked from the suction port 17 by using this volume change, and is configured to be discharged from the discharge port 18.

  The material of the component parts is that the pump head cover 11A and the pump body 11B are die-cast aluminum, the inner rotor 12A constituting the pump rotor 12, the outer rotor 12B is an iron-based sintered soft magnetic material, and the drive shaft 14 is carbon. The steel and oil seal 13 is made of a rubber material considering heat resistance and oil resistance.

  In the conventional trochoid pump, the outer teeth of the inner rotor 12A and the inner teeth of the inner rotor storage chamber 16 are engaged with each other and rotate while sliding. Therefore, as shown in FIG. Exists.

  The smaller the inter-tooth gap 19 is, the less oil leaks from the discharge side to the suction side. However, the outer teeth of the inner rotor 12A and the inner teeth of the outer rotor 12B are fitted and rotate smoothly while sliding. For this purpose, a certain amount of interdental gap 19 is necessary, which hinders improvement in pump efficiency.

Further, when such a trochoid pump 10 is mounted on an automobile, if an impact occurs due to the automobile traveling on a rough road or a step, an interdental gap 19 between the outer teeth of the inner rotor 12A and the inner teeth of the outer rotor 12B. , Each other collides and emits a collision sound.
Depending on the installation location of the pump, this collision sound reached the passenger's ear, which caused the passenger to feel uncomfortable.

  Next, with respect to this problem, the present embodiment is implemented to suppress the collision noise by suppressing the oil leakage from the discharge side to the suction side by minimizing the interdental gap 19 while maintaining the smooth rotation of the pump rotor 12. A detailed configuration of the embodiment will be described. In the present embodiment, the inter-tooth gap 19 which is a fitting portion between the outer teeth of the inner rotor 12A and the inner teeth of the outer rotor 12B is minimized, the oil leakage from the discharge side to the suction side is suppressed, and the collision In order to suppress the noise, the tooth top 12Aa and the tooth bottom 12Ab of the outer teeth of the inner rotor 12A, the tooth top 12Ba and the tooth bottom 12Bb of the inner teeth of the outer rotor 12B are respectively magnetized in the radial direction, and the inner rotor 12A The outer teeth 12Aa and the inner teeth 12Ba of the outer rotor 12B are magnetized to the same polarity, and the outer teeth 12Ab of the inner rotor 12A and the inner teeth 12Bb of the outer rotor 12B are the same. Magnetized in the pole.

  FIG. 1B is a plan view of the pump rotor 12. This figure is a diagram showing a specific magnetization arrangement in the pump rotor 12, as viewed from the thrust direction.

  As a specific example, the outer tooth tip 12Aa and the tooth bottom 12Ab of the inner rotor 12A are magnetized to the S pole, and the inner tooth tip 12Ba and the tooth bottom 12Bb of the outer rotor 12B are magnetized to the N pole. In order to avoid the complexity of the drawing, some of the magnetic poles are not shown.

  With respect to the inner rotor 12A, the outer rotor 12B is eccentrically arranged on the left side toward the paper surface, and is fitted on the right side toward the paper surface. At this time, since the inner rotor 12A and the outer rotor 12B are engaged with each other with different polarities, a magnetic attractive force acts. At that time, the interdental gap 19 shown in FIG. 1 (d) is minimized like the interdental gap 20 of the present invention shown in FIG. 1 (c), so that oil leakage from the discharge side to the suction side is suppressed. It becomes possible to do.

  Moreover, since it is like the interdental gap 20 of the present invention, when the impact occurs, the mutual moving distance between the inner rotor 12A and the outer rotor 12B is minimized, so that the impact sound when the two collide with each other is generated. Will be alleviated.

(Embodiment 2)
FIG. 2 is a perspective sectional view of the trochoid pump according to the second embodiment of the present invention.

  In the present embodiment, the tooth tops 12Aa and bottoms 12Ab of the outer teeth of the inner rotor 12A and the tooth tops 12Ba and bottoms 12Bb of the inner teeth of the outer rotor 12B are magnetized in the radial direction and the thrust direction, respectively.

  In the radial direction, the outer teeth 12Aa of the inner rotor 12A and the inner teeth 12Ba of the outer rotor 12B are magnetized to the same polarity, and the outer teeth 12Ab and outer rotor 12B of the inner rotor 12A are magnetized. The tooth bottom 12Bb of the inner teeth is magnetized to the same polarity.

  In the thrust direction, magnetization is arranged in different polarities at each tooth tip and tooth bottom. As a specific example, the south pole is magnetized and arranged on the upper end face of the external tooth tip 12Aa of the inner rotor 12A, and the north pole is placed on the lower end face. The other portions are similarly magnetized and arranged with different polarities.

According to this embodiment, since there is a magnetic path not only in the radial direction but also in the thrust direction and the magnetomotive force loss from the N pole to the S pole can be reduced, a stronger magnetic force can be generated. Is possible.

  As a result, it is possible to further suppress oil leakage from the discharge side to the suction side, and to mitigate the impact sound when they collide with each other.

(Embodiment 3)
In the present embodiment, the inner rotor 12A and the outer rotor 12B are made of magnetic material.

  Therefore, it is possible to generate a stronger magnetic force.

  As a result, it is possible to further suppress oil leakage from the discharge side to the suction side, and to mitigate the impact sound when they collide with each other.

(Embodiment 4)
FIG. 3 is a plan view of a pump rotor according to the fourth embodiment of the present invention.

  In the present embodiment, the magnetic bodies 22 are respectively inserted or integrally formed in the outer teeth 12Aa of the inner rotor 12A and the inner teeth 12Ba of the outer rotor 12B.

  By inserting or integrally molding the magnetic body 22 into the pump rotor 12 made of a soft magnetic body, the material cost can be reduced and the magnetic body can be suppressed as compared with the third embodiment in which the pump rotor 12 is formed of a magnetic body. Since 22 is used, it is possible to obtain a stronger magnetic force than in the first and second embodiments.

  As described above, when the oil pump rotor of the present invention is used in a vehicle, oil leakage between the suction side and the discharge side in the interdental gap can be reduced, the pump efficiency can be improved, and the automobile is bad. Even when an impact is generated by traveling on a road or a step, it is possible to mitigate and suppress the impact sound generated by the collision.

  The inscribed gear type oil pump according to the first to fourth embodiments described above is magnetized by a magnetic field from an external magnetic field source.

  The present invention can also be applied to tooth forms other than trochoids.

  The present invention is suitable for on-vehicle use as described above, and can be used for other devices that require a highly efficient and quiet oil pump.

DESCRIPTION OF SYMBOLS 10 Trochoid pump 11 Pump main body 11A Pump head cover 11B Pump body 12 Pump rotor 12A Inner rotor 12B Outer rotor 13 Oil seal 14 Drive shaft 15 Pump rotor storage hole 16 Inner rotor storage chamber 17 Intake port 18 Discharge port 19 Interdental gap 20 This invention Interdental gap 21 Magnetic flux line 22 Magnetic body

Claims (4)

A pump body having a pump rotor housing hole formed at a position eccentric with respect to the drive shaft as a central axis; an outer rotor which is rotatably housed in the pump rotor housing hole and has internal teeth; and the outer rotor An inner rotor disposed on the drive shaft, a pump head cover that closes the pump rotor housing hole to form a pump rotor housing portion, the pump body, In an internal gear type oil pump having an inlet and an outlet formed in at least one of a pump head cover, the inner rotor and the outer rotor are made of a soft magnetic material, and the inner rotor, An oil pump rotor characterized in that each tooth tip and tooth bottom of the outer rotor are magnetized. 2. The oil pump rotor according to claim 1, wherein each tooth tip and bottom of each of the inner rotor and the outer rotor are magnetized to have different polarities in the thickness direction (thrust direction). A pump body having a pump rotor housing hole formed at a position eccentric with respect to the drive shaft as a central axis; an outer rotor which is rotatably housed in the pump rotor housing hole and has internal teeth; and the outer rotor An inner rotor disposed on the drive shaft, a pump head cover that closes the pump rotor housing hole to form a pump rotor housing portion, the pump body, In an internal gear type oil pump having a suction port and a discharge port formed in at least one of a pump head cover, the inner rotor and the outer rotor are made of a magnetic material, and the inner rotor, the outer rotor An oil pump rotor, wherein each tooth tip and tooth bottom of the rotor are magnetized. 3. The oil pump rotor according to claim 1, wherein a magnetic material is embedded in both the inner rotor and the outer rotor.

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