JPH0542686U - Inscribed oil pump - Google Patents

Abstract

(57) [Abstract] [Purpose] The inner rotor of an oil pump designed to prevent the inner rotor from performing unstable behavior due to the presence of a side clearance between the inner rotor and the cover side and causing wear and fluctuations in the discharge amount. Offer. [Structure] An annular groove 10 is provided around an inner rotor facing surface of a spigot type bearing portion 7 of a pump housing 5, and a communication passage 1 for guiding discharged oil from a discharge chamber 11 to the annular groove 10 is formed.
An internal contact type oil pump in which 2 is provided to bias the inner rotor toward the inner wall surface of the cover 6 by the hydraulic pressure of the pressure oil on the discharge side guided to the annular groove 10.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an inscribed oil pump, and more specifically, an inner rotor fitted to a drive shaft extending from a crankshaft and an outer rotor inscribed in the inner rotor are housed in a pump housing, and a cover is provided on the pump housing. Of the inscribed type oil pump.

[0002]

[Prior Art]

 As a conventional inscribed oil pump of this type, for example, the one disclosed in Japanese Utility Model Laid-Open No. 59-71985 is known. In such a conventional inscribed oil pump, the rotation of the inner rotor fitted to the drive shaft causes the outer rotor accommodated in the pump housing to move eccentrically with respect to the inner rotor, so that the outer teeth of the inner rotor and the inner teeth of the outer rotor are interlocked with each other. The oil is guided to the formed volume chamber from the suction chamber side and is guided to the discharge chamber side.

[0003]

[Problems to be solved by the device]

 However, in the internal oil pump as in the above-mentioned conventional example, the housing cover is attached to the pump housing in such a manner that the inner rotor and the outer rotor are rotatably accommodated in the pump housing. In this case, the inner surface of the cover and the inner rotor are Generally, there is a clearance (side clearance) between the side surface and the inner rotor, which is rotating, is pressed against the cover side or mounted on the opposite housing side. Move to. If the inner rotor is biased toward the housing in such a state, the side clearance becomes maximum and the inner rotor is prone to incline, which makes the behavior unstable. Therefore, there has been a problem that such an inclination causes partial contact between the inner rotor and the cover, which causes great wear between the inner rotor and the cover, and changes in the side clearance make the oil discharge amount unstable.

An object of the present invention is to provide an inscribed type oil pump in which the stable rotation of the inner rotor ensures a stable oil discharge amount in order to solve the above-mentioned conventional problems. It is in.

[0005]

[Means for Solving the Problems]

 In order to achieve such an object, in the internal oil pump according to claim 1 of the present invention, an inner rotor fitted to a pump drive shaft and an outer rotor eccentrically inscribed in the inner rotor are housed in a pump housing. However, in an inscribed oil pump in which the rotating inner rotor is held between the bearing portion on the pump housing side and the inner wall surface of the housing cover, an annular groove is formed around the inner rotor side surface of the bearing portion. And a communication passage for guiding the pressurized oil discharged between the annular groove and the oil discharge chamber of the pump housing is provided, and the inner rotor is fixed to the housing cover by the pressure oil guided to the annular groove. It is configured to be biased toward the inner wall surface of the.

Further, in the inscribed oil pump according to claim 2 of the present invention, in particular, the inner rotor is made of a magnetic material, and a permanent magnet is provided on a surface of the housing cover facing the inner rotor side. The inner rotor is biased toward the inner wall surface of the housing cover by the magnetic force of a permanent magnet.

Further, in the inscribed oil pump according to the third aspect of the present invention, in particular, an annular groove is circumferentially provided on the opposing surface of the inner rotor side surface, and the annular groove and the oil suction chamber of the pump housing are provided. A negative pressure communication passage communicating with each other is formed, and the inner rotor is biased toward the inner wall surface of the housing cover by the negative pressure generated in the suction chamber by the pump action.

Further, in the inscribed oil pump according to the fourth aspect of the present invention, in particular, a permanent magnet is provided on the surface facing the inner rotor, and the inner rotor on the surface facing the permanent magnet repels the permanent magnet. The permanent magnets are provided in the direction of rotation, and the inner rotor is biased toward the inner wall surface of the housing cover by the repulsive force of both permanent magnets.

[0009]

[Action]

 In the inscribed oil pump according to the first aspect of the present invention, the pressurized oil is introduced from the discharge chamber through the communication passage to the annular groove provided on the opposite surface of the inner rotor side surface of the bearing portion. By displacing the inner rotor toward the inner wall surface of the cover, the rotating inner rotor behaves in an unstable manner and slidably contacts the inner wall surface of the cover, causing wear and oil discharge between them. Prevent instability.

In the inscribed oil pump according to the second aspect of the present invention, the inner rotor is biased toward the inner wall surface of the cover by the magnetic force of the permanent magnet, so that the rotating inner rotor causes unstable behavior. The slanted contact with the inner wall surface of the cover prevents abrasion between them and unstable oil discharge.

In the internal oil pump according to the third aspect of the present invention, the negative pressure generated in the suction chamber by the pump action causes the inner rotor to be biased toward the inner wall surface of the cover, so that the rotating inner rotor becomes unstable. This behavior prevents the behavior of sliding the inner wall surface of the cover in an inclined manner, causing wear between them and unstable oil discharge rate.

In the inscribed oil pump according to the fourth aspect of the present invention, the revolving force of the permanent magnet causes the inner rotor to be biased toward the inner wall surface of the cover, so that the rotating inner rotor causes unstable behavior. The slanted contact with the inner wall surface of the cover prevents abrasion between the two and unstable oil discharge.

[0013]

【Example】

 Embodiments of the present invention will be specifically described below with reference to the drawings.

First, an embodiment corresponding to claim 1 of the present invention will be described. Here, in FIG. 1, 1 is a crankshaft, 2 is a pump drive shaft extending from the crankshaft 1, 3 is an inner rotor fitted to the pump drive shaft 2, and 4 is an inner rotor 3 inscribed in the inner rotor 3. An outer rotor 5 which is interlocked with the narotor 3 is a pump housing which rotatably stores the outer rotor 4, and 6 is a housing cover which is fixed to the pump housing 5 by bolts or the like (not shown). A driving force transmitting surface 2A parallel to each other is formed on the pump drive shaft 2 to which the inner rotor 3 is fitted, and the driving force is transmitted from the driving shaft 2 to the inner rotor 3 via the transmitting surface 2A. Further, a stepped spigot part 3A is circumferentially provided on the pump housing 5 side of the inner rotor 3, and the spigot part 3A is pivotally supported by a bearing part 7 on the pump housing 5 side fitted with the spigot part 3A. . Reference numeral 8 is an oil seal provided around the shaft on the pump housing 5 side.

In the internal oil pump having such a configuration, in this embodiment, the annular groove 10 is circumferentially provided on the radial wall surface of the bearing portion 7 to which the spigot portion 3A of the inner rotor 3 is fitted. Further, an oil communication passage 12 that communicates with the annular groove 10 from the discharge chamber 11 is bored so that the pressurized oil delivered to the discharge chamber 11 is guided from the communication passage 12 to the annular groove 10, and the oil The pressure causes the inner rotor 3 to be biased toward the inner wall 6A of the cover 6. Here, since the inner rotor 3 is fitted to the pump drive shaft 2 in such a manner as to allow axial movement, the inner rotor 3 slides along the drive shaft 2 by the above-mentioned hydraulic pressure and faces the inner rotor 3 of the cover inner surface wall 6A. The side surface of the rotor 3 is evenly and lightly pressed against the section. Therefore, it is possible to prevent the inner rotor 3 from tilting as in the conventional art due to the clearance between the inner rotor 3 and the cover 6 and the clearance between the inner rotor 3 and the pump drive shaft 2, and the inner wall 6A of the cover from being worn down. be able to.

Next, another embodiment of the present invention will be described. The same components as those in the above embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

In the embodiment shown in FIG. 2, the inner rotor 30 is made of a magnetic material such as iron, and the permanent magnet 9 is embedded in the surface of the housing cover 6 facing the inner rotor 30 side surface.

In this embodiment, the inner rotor 30 is biased toward the inner wall surface 6 A of the housing cover 6 by the magnetic force of the permanent magnet 9. Therefore, the same effect as that of the above embodiment can be obtained.

In the embodiment shown in FIG. 3, an annular groove 100 is provided around the wall surface of the housing cover 6 facing the inner rotor 3 side surface. Further, a negative pressure communication passage 120 communicating from the suction chamber 15 to the annular groove 100 is bored so that the negative pressure generated in the suction chamber 15 by the pump action is guided from the negative pressure communication passage to the annular groove 100. The suction negative pressure biases the inner rotor 3 toward the inner wall 6A of the cover 6. Therefore, the same effect as that of the above-mentioned embodiment can be obtained.

In the embodiment shown in FIG. 4, a permanent magnet 90 is provided on the facing surface of the side surface of the inner rotor 3 in the bearing portion 7, and the inner rotor 3 on the facing surface of the permanent magnet 90 is in a direction repelling the permanent magnet 90. Then, the permanent magnet 900 is provided, and the inner rotor 3 is biased toward the inner wall 6A of the cover 6 by the repulsive force of both the permanent magnets. Therefore, the same effect as that of the above embodiment can be obtained.

[0021]

[Effect of the device]

 As described above, according to claim 1 of the present invention, an annular groove is provided around the inner rotor side surface of the bearing portion so as to surround the annular groove and the oil discharge chamber of the pump housing. A communicating passage for guiding the pressurized oil discharged is provided between the inner and outer circumferential surfaces of the housing cover so that the inner rotor is biased toward the inner wall surface of the housing cover by the pressurized oil guided to the annular groove. The inner rotor can be biased toward the inner wall of the cover by the hydraulic pressure acting on the inner rotor. According to the second aspect of the present invention, the magnetic member is provided on the surface of the inner rotor facing the cover. The magnetic force of the magnetic member can bias the inner rotor toward the inner wall surface of the cover.

According to a third aspect of the present invention, an annular groove is provided around an inner rotor side surface of the housing cover, and a negative pressure communication passage is formed to communicate the annular groove with the oil suction chamber of the pump housing. The inner rotor can be biased toward the inner wall surface of the housing cover by the negative pressure generated in the suction chamber by the pump action.

Further, according to a fourth aspect of the present invention, a permanent magnet is provided on the facing surface of the inner rotor side surface of the bearing portion, and the inner rotor on the facing surface of the permanent magnet is in a direction repulsive to the permanent magnet. A permanent magnet is provided, and the inner rotor can be biased toward the inner wall surface of the cover by the repulsive force of both the permanent magnets. Therefore, in any case, it is possible to prevent the inner rotor from behaving in an unstable manner such as tilting during rotation, and the inner rotor and the inner wall may be worn down due to uneven contact with the inner wall of the inner rotor cover. It is possible to contribute to securing a stable discharge amount as well as suppressing the occurrence of

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of the structure of an inscribed oil pump according to claim 1 of the present invention.

FIG. 2 is a sectional view showing an example of the structure of an inscribed oil pump according to claim 2 of the present invention.

FIG. 3 is a sectional view showing an example of the structure of an inscribed oil pump according to claim 3 of the present invention.

FIG. 4 is a sectional view showing an example of the structure of an inscribed oil pump according to claim 4 of the present invention.

[Explanation of symbols]

 1 Crankshaft 2 Pump Drive Shaft 2A Drive Force Transmission Surface 3 Inner Rotor 3A Inlay Part 4 Outer Rotor 5 Pump Housing 6 Cover 6A Cover Inner Surface Wall 9,90,900 Permanent Magnets 10,100 Annular Groove 11 Discharge Chamber 12 Communication Passage 13 Side Clearance 14 Negative pressure communication passage 15 Suction chamber

Claims (4)

[Scope of utility model registration request] 1. An inner rotor fitted to a pump drive shaft and an outer rotor eccentrically inscribed in the inner rotor are housed in a pump housing, and the rotating inner rotor is provided with a bearing portion on the pump housing side and an inner wall surface of a housing cover. In the inward oil pump, which is configured to be held between the inner bearing and the inner rotor, a ring groove is provided around the inner rotor side surface of the bearing, and the ring groove is discharged between the ring groove and the oil discharge chamber of the pump housing. An inscribed oil pump, wherein a communication passage for introducing pressurized oil is provided, and the inner rotor is biased toward the inner wall surface of the housing cover by the pressurized oil guided to the annular groove. 2. An inner rotor fitted to a pump drive shaft and an outer rotor eccentrically inscribed in the inner rotor are housed in a pump housing, and the rotating inner rotor is provided with a bearing portion on the pump housing side and an inner wall surface of a housing cover. In an internal contact type oil pump that is held between the inner cover and the inner rotor, a permanent magnet is provided on the surface of the housing cover that faces the inner rotor side surface, and the inner rotor is biased toward the inner wall surface of the housing cover by the magnetic force of the permanent magnet. An inscribed type oil pump characterized in that 3. An inner rotor fitted to a pump drive shaft and an outer rotor eccentrically inscribed in the inner rotor are housed in a pump housing, and the rotating inner rotor is provided with a bearing portion on the pump housing side and an inner wall surface of a housing cover. In an inscribed oil pump held between the inner cover and the inner rotor side surface of the housing cover, an annular groove is formed around the annular groove, and the negative groove communicates with the annular groove and an oil suction chamber of the pump housing. The internal rotor type oil pump is characterized in that the inner rotor is biased toward the inner wall surface of the housing cover by the negative pressure generated in the suction chamber by the pump action. 4. An inner rotor fitted to a pump drive shaft and an outer rotor eccentrically inscribed in the inner rotor are housed in a pump housing, and the rotating inner rotor is provided with a bearing portion on the pump housing side and an inner wall surface of a housing cover. In the internal oil pump, the permanent magnet is provided on the facing surface of the inner rotor side surface of the bearing portion, and the inner rotor on the facing surface of the permanent magnet has a permanent magnet in a direction repelling the permanent magnet. An inscribed oil pump, wherein a magnet is provided, and the inner rotor is biased toward the inner wall surface of the housing cover by the repulsive force of both permanent magnets.