JPH0628285U - Oil pump rotor lubrication structure - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the lubrication of the outer peripheral surface of the outer rotor and the sliding surface of the housing to eliminate noise and vibration. An outer rotor 5 having inner teeth 4 is rotatably accommodated in a housing 3, and an inner rotor 7 having outer teeth 6 meshing with the inner teeth 4 is rotatably accommodated in the outer rotor 5. Has been done. On the outer peripheral surface of the outer rotor 5, a plurality of oil pools 11 elongated in the axial direction are provided.
Are provided at predetermined intervals in the circumferential direction, and the oil sump 11
Thus, the oil on the discharge side is sent to the suction side, and a lubricating oil film is formed. The end of the oil sump 11 and the outer rotor 5
A small land portion 12 is provided between the outer peripheral edge portions of
There is no circumferential cut between adjacent oil sumps 11. For this reason, the foreign matter caught between the outer rotor 5 and the sliding surface of the housing 3 is taken into the oil sump 11 as soon as possible.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an oil pump rotor lubrication structure applied to a transmission control system of an automobile transmission.

[0002]

[Prior art]

 As shown in FIGS. 5 and 6, this type of oil pump rotatably houses an outer rotor 5 having internal teeth 4 in a pump chamber 3 of a housing 2 covered by a cover 1. An inner rotor 7 having outer teeth 6 meshing with its inner teeth 4 is housed in an outer rotor 5 in a rotatable manner. The housing 2 has a suction port 9 communicating with a plurality of closed spaces 8 on the right side in FIG. 6 among a plurality of closed spaces 8 formed by the inner teeth 4 and the outer teeth 6, and a plurality of left closed spaces. And a discharge port 10 communicating with 8. In this oil pump, when the inner rotor 7 is rotationally driven and oil is sucked into the closed space 8 between the inner teeth 4 and the outer teeth 6 from the suction port 9, the oil is closed as the inner rotor 7 rotates. When the volume of the charging space 8 changes, it is pressurized to a predetermined pressure and discharged from the discharge port 10.

[0003]

[Problems to be solved by the device]

However, in the conventional oil pump, as shown in FIG. 6, the pressure-receiving diameter D _{1 on} the inner peripheral surface of the outer rotor 5 is smaller than the pressure-receiving diameter D ₂ on the outer peripheral surface, so that it acts on the inner peripheral surface on the discharge side. than the pressing force F ₂ of the outer peripheral surface than the pressure of the pressing force F ₁ becomes larger, the outer rotor 5 is pushed into the suction side of the gap between the outer peripheral surface and the housing 2 of the suction side is reduced, the discharge side The higher the oil pressure of the outer rotor 5, the greater the force with which the outer rotor 5 presses the sliding surface of the housing 2 becomes, resulting in insufficient lubrication, noise and vibration, and scratches on the sliding surface. There was a problem. The present invention has been made in view of the above problems, and an object thereof is to provide a rotor lubrication structure for an oil pump that does not cause noise or vibration by improving the lubrication of the outer peripheral surface of the outer rotor and the sliding surface of the housing. It is what

[0004]

[Means for Solving the Problems]

 To achieve the above object, the present invention rotatably accommodates an outer rotor having internal teeth in a housing, and enables an inner rotor having external teeth meshing with the inner teeth to be rotationally driven in the outer rotor. In the contained oil pump, a plurality of oil pools elongated in the axial direction are provided at a predetermined interval in the circumferential direction on the outer peripheral surface of the outer rotor, and between the end of the oil pool and the outer peripheral edge of the outer rotor. A small land area is provided and adjacent oil pools overlap each other in the circumferential direction. The oil reservoir preferably has a width of 0.1 to 3 mm and a depth of 10 μ to 1 mm.

[0005]

[Action]

 According to the above configuration, even if the pressure on the discharge side rises and the outer rotor is pressed toward the suction side, the oil taken in by the discharge side into the oil reservoir provided on the outer peripheral surface of the outer rotor causes the outer rotor on the suction side. Since it is fed between the housing and the sliding surface of the housing, good lubrication is achieved. In addition, the oil pools of the outer rotor overlap each other in the circumferential direction and there is no break in the circumferential direction except for the land on the outer peripheral edge, so it is not possible to slip between the outer rotor and the sliding surface of the housing. The foreign matter that is trapped is taken into the oil puddle as soon as possible.

[0006]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a rotor lubrication structure according to the present invention. In FIG. 1, reference numeral 2 is a housing, 5 is an outer rotor, and 7 is an inner rotor. Since these operations are the same as those of the conventional one described above, the description thereof is omitted. To do. On the outer peripheral surface of the outer rotor 5, elongated oil reservoirs 11 are formed in the axial direction at predetermined intervals. In this embodiment, the oil sump 11 has a width W = 0.5 mm and a depth D = 30 μ, but the width W is preferably 0.1 to 3 mm and the depth D is preferably 10 μ to 1 mm. Specifically, it should be determined in consideration of the size of the rotor, oil suction and discharge pressure, oil properties, and the distance between adjacent oil sumps. As shown in FIG. 2, if the depth D is too deep, a space is created and the range where the oil film pressure is generated is narrowed. Therefore, the depth D should be made as shallow and wide as possible. The length L of the oil sump 11 is arbitrary, but in this embodiment, it is about 1/2 of the thickness of the outer rotor 5.

The oil sump 11 is located at the center of the outer rotor 5 in the thickness direction of the outer rotor 5 and the first oil sump 11 a which is close to the outer peripheral edge on the cover side via a land 12 of about 1 mm (indicated by A in the figure). It consists of a second oil sump 11b that is located and a third oil sump 11c that is adjacent to the housing, leaving a land 12 of about 1 mm (indicated by B in the figure) on the outer peripheral edge of the housing. They are arranged alternately and are arranged so that only the dimensions S ₁ and S ₂ appropriately overlap each other in the outer peripheral direction. Therefore, on the outer peripheral surface of the outer rotor 5, except for the land portion 12, there is an oil sump 11 which is continuous in the circumferential direction.

In the oil pump having the lubrication structure in which the oil pool 11 is formed on the outer peripheral surface of the outer rotor 5 as described above, as described above, the outer rotor 5 is sucked by the surface area difference between the inner and outer surfaces of the outer rotor 5. Pressed to the side. This pressure increases as the pressure on the discharge side increases, but the oil accumulated in the oil sump 11 on the discharge side on the outer peripheral surface of the outer rotor 5 is sent to the suction side as the outer rotor 5 rotates. Therefore, the oil film between the outer peripheral surface of the outer rotor 5 and the sliding surface of the housing 2 on the suction side is maintained without disappearing, and good lubrication is performed. Therefore, even if the pressure on the discharge side is high, no vibration or noise occurs.

Further, since the oil sumps 11 overlap each other in the circumferential direction and have no breaks along the outer peripheral surface of the outer rotor 5, foreign matter mixed in the oil film is always taken into one of the oil sumps 11. Be done. Therefore, the outer peripheral surface of the outer rotor 5 and the sliding surface of the housing 2 are not damaged by the foreign matter. The shape and the circumferential arrangement of the oil sump 12 are not limited to those shown in FIG. 1, but the staggered shape shown in FIG. 4 (a), the parallel shape shown in FIG. 4 (b), and the cross shape shown in FIG. 4 (c). Etc. can be arbitrarily set. In this case, as described above, it is important to leave the land portion 12 and to wrap the land portion 12 so that there is no break in the circumferential direction.

[0010]

[Effect of device]

 As is clear from the above description, according to the present invention, the oil pool provided on the outer peripheral surface of the outer rotor favorably lubricates the outer rotor and the sliding surface of the housing, and between them. The foreign objects caught in the oil trap are taken into the oil sump, so there is no vibration or noise, and the sliding surface is not scratched.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an oil pump to which a lubricating structure according to the present invention is applied.

FIG. 2 is a vertical cross-sectional view showing a lubricated state between an outer rotor and a housing of the oil pump shown in FIG.

FIG. 3 is a cross-sectional view showing a preferable lubrication state between the outer rotor and the housing of the oil pump shown in FIG.

FIG. 4 is a development view showing various other shapes of an oil pool on the outer peripheral surface of the outer rotor.

FIG. 5 is a vertical sectional view of an oil pump.

FIG. 6 is an enlarged front view showing a state where the cover of the oil pump shown in FIG. 5 is removed.

[Explanation of symbols]

2 ... Housing, 4 ... Inner teeth, 5 ... Outer rotor, 6 ... Outer teeth, 7 ... Inner rotor,
11 ... oil pool, 12 ... land part.

Claims (2)

[Scope of utility model registration request] 1. An oil pump in which an outer rotor having internal teeth is rotatably accommodated in a housing, and an inner rotor having external teeth meshing with the inner teeth is rotatably accommodated in the outer rotor, On the outer peripheral surface of the outer rotor, a plurality of oil reservoirs elongated in the axial direction are provided at predetermined intervals in the circumferential direction, and a small land portion is provided between the end of the oil reservoir and the outer peripheral edge of the outer rotor. A rotor lubrication structure for an oil pump, characterized in that adjacent oil reservoirs overlap each other in the circumferential direction. 2. The oil pool has a width of 0.1 to 3 mm.
And the depth is 10 μ to 1 mm, and the rotor lubrication structure for the oil pump according to claim 1.