JPH0589880U - Oil pump - Google Patents

Abstract

(57) [Abstract] [Purpose] An oil pump used in a transfer device or the like is intended to be miniaturized by eliminating the need for a relief valve. [Structure] A check ball or check roller and a storage part for storing a spring for pressing the check ball or check roller against a drive gear are formed on the shaft, and a groove having an inclined surface into which the check ball or check roller is inserted is driven. I made it into a gear.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an oil pump used for a transfer device or the like.

[0002]

[Prior Art]

 Conventional oil pumps include those shown in FIGS. 6 and 7, for example. In FIG. 6, reference numeral 1 is a main shaft of the transfer device, and the main shaft 1 is rotatably supported by a casing 3 via a bearing 2.

A drive sprocket 4 is rotatably supported on a main shaft 1 via a bearing 5, and a chain 8 is installed between the drive sprocket 4 and a driven sprocket 7 integrally formed on a front drive shaft 6. ing. Further, an oil pump 11 including a driving gear 9 and a driven gear 10 is provided on the main shaft 1, and the oil pump 11 sucks the oil from which dust has been removed by the strainer 12 through the suction passage 13. ..

That is, the oil is sucked from the suction port 14, and pumped by the driving gear 9 and the driven gear 10 to discharge each oil from the discharge port 15 through the oil hole 16 formed in the main shaft 1 and the oil passage 17. It is pumped to the site. The drive gear 9 is fixed to the main shaft 1 by a pin 18. Here, as shown in FIG. 7, a relief valve 20 is provided in the oil passage 19 communicating with the discharge port 15.

The oil discharged from the oil pump 11 is designed to escape from the oil passage 21 to the suction port 14 by the relief valve 20 even if the discharge pressure rises due to some abnormality. That is, as shown in FIG. 8, the relief pressure 20 prevents the discharge pressure A from exceeding a prescribed pressure (relief pressure) B.

[0006]

[Problems to be solved by the device]

 However, in such a conventional oil pump, since a relief valve is separately provided so that the oil discharged from the oil pump does not exceed a specified pressure, there is a problem that the oil pump becomes large. was there. The present invention has been made in view of such conventional problems, and an object thereof is to provide an oil pump that can be downsized by eliminating the need for a relief valve.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a check ball or a check roller in an oil pump having, for example, a drive gear provided on a shaft and a driven gear provided outside the drive gear. A storage part for storing a spring for pressing the check ball or check roller against the drive gear is formed in the shaft, and a groove having an inclined surface into which the check ball or the check roller is inserted is formed in the drive gear. Is.

[0008]

[Action]

 According to the present invention, the check ball or the check roller is pressed against the groove of the driving gear by the spring during the normal running when the discharge pressure is less than the specified pressure, and the shaft and the driving gear rotate integrally with each other, and the normal oil pump Function as. On the other hand, when the discharge pressure exceeds the specified pressure, the drive resistance of the oil pump overcomes the check force, and the check ball or check roller comes off the groove of the drive gear, causing the shaft to idle.

Therefore, the oil pump does not operate as a pump, and the discharge pressure drops below the specified pressure. As a result, the relief valve, which was conventionally installed as a separate body, becomes unnecessary, and the size can be reduced.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 are views showing an embodiment of the present invention. First, the configuration will be described. In FIGS. 1 and 2, 31 is, for example, a main shaft (shaft) of the transfer device, and the shaft 31 rotates in a direction indicated by an arrow C.

Reference numeral 32 denotes a drive gear that is rotatable integrally with the shaft 31, and the drive gear 32 has a plurality of tooth portions 33. A driven gear 34 is provided outside the driving gear 32, and the driven gear 34 has a plurality of tooth portions 35 that mesh with the tooth portions 33 of the driving gear 32. The drive gear 32 and the driven gear 34 constitute an oil pump 36 as a whole.

A storage portion 37 is formed on the shaft 31, and a check ball 38, a ball holder 39 for holding the check ball 38, and a spring 40 for pressing the ball holder 39 are provided in the storage portion 37. It is stored. A check ball 38 and a ball retainer 39 that holds the check ball 38 are shown in FIG.

Instead of the check ball 38 and the ball holder 39, a check roller 41 and a roller holder 42 holding the check roller 41 as shown in FIG. 4 may be used. On the other hand, on the inner circumference of the drive gear 32, a groove 43 (V groove) having an inclined surface into which the check ball 38 is inserted is formed.

Next, the operation will be described. As shown in FIG. 5, during normal traveling in which the discharge pressure A is equal to or lower than the specified pressure (relief pressure) B, the check ball 38 is pressed into the groove 43 of the drive gear 32 by the spring 40 provided in the storage portion 37. As shown by arrows C and D, the shaft 31 and the drive gear 32 rotate integrally and function as a normal oil pump 36.

Next, as shown in FIG. 5, when the discharge pressure A exceeds the specified pressure B, the drive resistance of the oil pump 36 increases, so that the check ball 38 comes off from the groove 43 of the drive gear 32. , The shaft 31 idles as indicated by arrow E. Therefore, the oil pump 36 does not perform the pumping action, and the discharge pressure A drops below the specified pressure B.

As a result, the relief valve, which is conventionally installed as a separate body, becomes unnecessary, and the size can be reduced.

[0017]

[Effect of the device]

 As described above, according to the present invention, when the discharge pressure exceeds the specified pressure, the check ball or the check roller is disengaged from the groove of the drive gear due to the increase of the drive resistance, and the pump action is not performed. Therefore, the relief valve, which was conventionally installed as a separate body, is unnecessary, and the size can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an operation at the time of relief.

FIG. 3 is a diagram showing a check ball and a ball cage.

FIG. 4 is a diagram showing a check roller and a roller holder.

FIG. 5 is a graph showing discharge pressure and relief pressure.

FIG. 6 is a partial cross-sectional view of a transfer device.

FIG. 7 is a diagram showing a conventional oil pump.

FIG. 8 is a graph showing discharge pressure and relief pressure.

[Explanation of symbols]

 31: Shaft 32: Drive gear 33: Tooth part 34: Driven gear 35: Tooth part 36: Oil pump 37: Storage part 38: Check ball 39: Ball retainer 40: Spring 41: Check roller 42: Roller retainer 43 :groove

Claims (1)

[Scope of utility model registration request] 1. An oil pump having a drive gear provided on a shaft and a driven gear provided outside the drive gear, wherein a check ball or a check roller and the check ball or the check roller are driven by the drive roller. An oil pump, characterized in that an accommodating portion for accommodating a spring pressed against a gear is formed in the shaft, and a groove having an inclined surface into which a check ball or a check roller is inserted is formed in the drive gear.