Internal gear pump with pressure relief channel

Abstract

The utility model discloses an internal gear pump with a pressure relief channel, which comprises a shell, the shell comprises a working cavity, an oil inlet and an oil outlet, a gear and a gear ring are arranged in the working cavity, a gear shaft penetrates through the shell, two bearings are arranged between the gear shaft and the shell, and the two bearings are distributed in the front-back direction of the working cavity. A low-pressure path is formed between the working cavity and the oil inlet, a high-pressure path is formed between the working cavity and the oil outlet, side plates are arranged between the two ends of the gear and the gear ring and the two axial side walls of the working cavity, high-pressure cavities are formed between the side plates and the axial side walls, and low-pressure cavities are further formed in the positions, corresponding to the outer ends of the bearings, of the two ends of the shell. The shell is provided with a pressure relief channel, the two ends of the pressure relief channel are connected with the high-pressure path and the low-pressure path respectively, and the pressure relief channel is used for leaking oil on the high-pressure path to the low-pressure path. According to the gear pump, the rotating speed of the gear pump during operation can be increased, and the heat dissipation capacity and the lubricating effect on the bearing are improved.

Description

Technical Field

[0001] The utility model relates to an internal meshing gear pump with a pressure relief channel. Background Art

[0002] In the field of hydraulic systems, internal gear pumps are widely used due to their compact structure and uniform flow.

[0003] Existing internal gear pumps are prone to bearing burnout when running for a long time at low speed and pressure. This is because the gear pump has a high volumetric efficiency. Under low speed and high pressure working conditions, most of the flow generated in the pump is used to make up for internal leakage, resulting in very little or no flow output at the outlet. At the same time, the low speed makes it difficult for the heat generated by the friction between the bearing and the gear shaft to be effectively removed by the oil, and the heat continues to accumulate at the bearing. As the temperature continues to rise, once the failure temperature of the bearing is reached, the bearing will be damaged, seriously affecting the normal operation and service life of the gear pump, and increasing the maintenance cost and downtime of the equipment. Utility Model Content

[0004] In order to overcome the defects of the prior art mentioned above, the utility model provides an internal meshing gear pump with a pressure relief channel, which can increase the rotation speed of the gear pump during operation and improve the heat dissipation capacity and lubrication effect of the bearing.

[0005] The utility model discloses an internal meshing gear pump with a pressure relief channel, comprising a shell, the shell comprising a working chamber, an oil inlet and an oil outlet connected to the working chamber, a gear and a gear ring are arranged in the working chamber, based on the cooperation of the gear and the gear ring, a high pressure area connected to the oil outlet and a low pressure area connected to the oil inlet are formed in the working chamber, a gear shaft connected to the gear is penetrated through the shell, the gear and the gear ring are driven to rotate in sequence by the gear shaft, two bearings are arranged between the gear shaft and the shell, the two bearings are distributed in the front and rear directions of the working chamber, and are used to support the rotation of the gear shaft, a low pressure path is formed between the low pressure area of ​​the working chamber and the oil inlet, and the working chamber A high-pressure path is formed between the high-pressure area and the oil outlet, side plates are arranged between the two ends of the gear and the gear ring and the two axial side walls of the working chamber, a high-pressure chamber connected to the working chamber is formed between the side plates and the axial side walls, the oil pressure in the high-pressure chamber is applied to the side plates, so that the side plates can be better pressed and contacted on the ends of the gear and the gear ring, low-pressure chambers are also arranged at the outer ends of the two ends of the outer shell at the corresponding bearings, and a connecting hole is also provided between the low-pressure chamber and the low-pressure area of ​​the working chamber for balancing the oil pressure, the outer shell is provided with a pressure relief channel, the two ends of the pressure relief channel are respectively connected to the high-pressure path and the low-pressure path, for leaking the oil on the high-pressure path to the low-pressure path.

[0006] When the gear pump is operating at low speed and high pressure, part of the hydraulic oil in the high-pressure path flows to the low-pressure path through the pressure relief channel. The flow of oil changes the pressure distribution in the pump, thereby increasing the operating speed of the pump and forming convection in the pump. This convection is conducive to the diffusion of heat in the pump, taking away the heat generated by friction, alleviating the problem of heat accumulation in the bearings under low-speed and high-pressure conditions, extending the operating time of the gear pump in this state, and reducing the noise caused by overheating. At the same time, it also makes it easier to form an oil film in the contact area between the gear shaft and the bearing, reducing the friction between the bearing and the gear shaft.

[0007] In the first preferred embodiment, the two ends of the pressure relief channel are connected to the oil inlet and the oil outlet, respectively. The working chamber is located at the center of the shell, and the oil inlet and the oil outlet are distributed on two adjacent side walls of the shell, and the pressure relief channel obliquely connects the oil inlet and the oil outlet. The pressure relief channel can be formed by only simple processing on the shell, and the structure is simple, the processing is relatively convenient, and the oil circuit layout is relatively simple. On the three-section shell structure, that is, the shell structure composed of the front cover, the pump body, and the rear cover, it is only necessary to process the pressure relief channel on the pump body, which is simple to process and low in cost.

[0008] In the second preferred embodiment, there are at least two pressure relief channels, and the two ends of the two pressure relief channels are respectively connected to the corresponding high-pressure chamber and low-pressure chamber, and part of the oil in the high-pressure chamber enters the low-pressure chamber through the pressure relief channel, passes through the contact area between the bearing and the gear shaft, and part of the oil enters the low-pressure area of ​​the working chamber through the connecting hole to achieve reflux, which can improve the heat dissipation and lubrication effect of the bearing.

[0009] Furthermore, the directions of both ends of the pressure relief channel are the same as the axial direction of the gear shaft, one end of the pressure relief channel is provided with an opening on the axial side wall, and the other end of the pressure relief channel is provided with an opening on the side wall of the low-pressure chamber. This facilitates the processing of the pressure relief channel and shortens the oil path. On a three-section housing structure, that is, a housing structure consisting of a front cover, a pump body, and a rear cover, it is only necessary to process the pressure relief channel on the front cover and the rear cover respectively, which is simple to process and low in cost.

[0010] Furthermore, the middle section of the pressure relief channel has a narrow hole, and the provision of the narrow hole can limit the flow rate of the oil flowing through the oil channel and increase the oil pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is an axial cross-sectional view of an embodiment of the utility model;

[0012] Figure 2 It is a radial cross-sectional view of another embodiment of the utility model. DETAILED DESCRIPTION

[0013] An internal gear pump with a pressure relief channel according to an embodiment of the utility model, such as Figure 1-2 As shown, it includes a shell, which includes a working chamber 10, an oil inlet 101 and an oil outlet 102 connected to the working chamber 10. The shell adopts a three-section structure, including a front cover 11, a pump body 12, and a rear cover 13. The working chamber 10 is composed of the front cover 11, the pump body 12, and the rear cover 13. A gear 21 and a gear ring 22 are arranged in the working chamber 10. Based on the cooperation of the gear 21 and the gear ring 22, a high-pressure area connected to the oil outlet 102 and a low-pressure area connected to the oil inlet 101 are formed in the working chamber 10. A gear shaft 23 connected to the gear 21 is penetrated by the shell, and the gear 21 and the gear ring 22 are driven to rotate in turn through the gear shaft 23. Two bearings 3 are arranged between the gear shaft 23 and the shell. The two bearings 3 are distributed in the front and rear directions of the working chamber 10 for supporting the rotation of the gear shaft 23. When the gear 21 and the gear ring 22 are meshed and rotated, they will rotate in the working chamber 10. A low-pressure zone and a high-pressure zone are respectively formed in the working chamber 10, a low-pressure path is formed between the low-pressure zone of the working chamber 10 and the oil inlet 101, and a high-pressure path is formed between the high-pressure zone of the working chamber 10 and the oil outlet 102. Side plates 4 are arranged between the two ends of the gear 21 and the gear ring 22 and the two axial side walls of the working chamber 10, and the two axial side walls are respectively located on the front cover 11 and the rear cover 13. A high-pressure chamber 51 connected to the working chamber 10 is formed between the side plate 4 and the axial side wall, and the oil pressure in the high-pressure chamber 51 is applied to the side plate 4, so that the side plate 4 can better press and contact the ends of the gear 21 and the gear ring 22. Low-pressure chambers 52 are also arranged at both ends of the housing at the outer end positions corresponding to the bearing 3, and a connecting hole 61 is also provided between the low-pressure chamber 52 and the low-pressure zone of the working chamber 10 for balancing the oil pressure. The two low-pressure chambers 52 are respectively arranged on the front cover 11 and the rear cover 13. The low-pressure chamber 52 located at the front side of the working chamber 10 is formed by the gear shaft 23, the shaft hole and the shaft sealing assembly located between the gear shaft 23 and the shaft hole, and the low-pressure chamber 52 located at the rear side of the working chamber 10 is formed by the gear shaft 23 and the pit connected to the end of the shaft hole.

[0014] like Figure 1 As shown, the housing is provided with a pressure relief channel, and both ends of the pressure relief channel are respectively connected to the high-pressure path and the low-pressure path, so as to leak the oil in the high-pressure path to the low-pressure path.

[0015] When the gear pump is in low-speed and high-pressure operation, part of the hydraulic oil in the high-pressure path flows to the low-pressure path through the pressure relief channel. The flow of oil changes the pressure distribution in the pump, thereby increasing the operating speed of the pump and forming convection in the pump. This convection is beneficial to the diffusion of heat in the pump, taking away the heat generated by friction, alleviating the problem of heat accumulation in the bearings under low-speed and high-pressure conditions, extending the operating time of the gear pump in this state, and reducing the noise caused by overheating. At the same time, it also makes it easier to form an oil film in the contact area between the gear shaft 23 and the bearing, thereby reducing the friction between the bearing and the gear shaft 23.

[0016] In this embodiment, if Figure 1 As shown, there are two pressure relief channels 62, and the two ends of the two pressure relief channels 62 are respectively connected to the corresponding high-pressure chamber 51 and low-pressure chamber 52. Part of the oil in the high-pressure chamber 51 enters the low-pressure chamber 52 through the pressure relief channel 62, passes through the contact area between the bearing 3 and the gear shaft 23, and part of the oil enters the low-pressure area of ​​the working chamber 10 through the connecting hole 61 to achieve reflux. This can improve the heat dissipation and lubrication effect of the bearing.

[0017] The two ends of the pressure relief channel 62 are in the same direction as the axis of the gear shaft 23. One end of the pressure relief channel 62 is provided with an opening on the axial side wall, and the other end of the pressure relief channel is provided with an opening on the side wall of the low-pressure chamber 52. The processing of the pressure relief channel is convenient, the oil path is shortened, and the processing is simple and low in cost. The middle section of the pressure relief channel 62 has a narrow hole 621, and the setting of the narrow hole 621 can limit the flow of oil flowing through the oil channel and increase the oil pressure.

[0018] In another embodiment, if Figure 2 As shown, another form of pressure relief channel 62 can also be used. Specifically, the two ends of the pressure relief channel 62 are respectively connected to the oil inlet 101 and the oil outlet 102. The working chamber 10 is located at the center of the shell, and the oil inlet 101 and the oil outlet 102 are distributed on two adjacent side walls of the shell. The pressure relief channel 62 obliquely connects the oil inlet 101 and the oil outlet 102. The pressure relief channel can be formed by simply processing the pump body 12 of the shell, with a simple structure, convenient processing, and simple oil circuit layout.

[0019] In order to further improve the effect, the above two types of pressure relief channels 62 can also be applied to the same product.

[0020] The above embodiment is only one of the preferred specific embodiments of the present invention. Common changes and substitutions made by those skilled in the art within the technical solution of the present invention are all included in the protection scope of the present invention.

Claims

1. An internal gear pump with a pressure relief channel, comprising a housing, the housing comprising a working chamber, an oil inlet and an oil outlet connected to the working chamber, a gear and a gear ring are arranged in the working chamber, a gear shaft connected to the gear is penetrated by the housing, two bearings are arranged between the gear shaft and the housing, the two bearings are distributed in the front and rear directions of the working chamber, a low-pressure path is formed between the working chamber and the oil inlet, a high-pressure path is formed between the working chamber and the oil outlet, side plates are arranged between the two ends of the gear and the gear ring and the two axial side walls of the working chamber, a high-pressure chamber connected to the working chamber is formed between the side plates and the axial side walls, low-pressure chambers are also arranged at the outer ends of the two ends of the housing at positions corresponding to the bearings, and a connecting hole is also provided between the low-pressure chamber and the working chamber, characterized in that: The housing is provided with a pressure relief channel, and both ends of the pressure relief channel are respectively connected to the high-pressure path and the low-pressure path, so as to leak the oil in the high-pressure path to the low-pressure path.

2. An internal gear pump with a pressure relief channel according to claim 1, characterized in that: The two ends of the pressure relief channel are connected to the oil inlet and the oil outlet respectively.

3. An internal gear pump with a pressure relief channel according to claim 2, characterized in that: The working chamber is located at the center of the shell, the oil inlet and the oil outlet are distributed on two adjacent side walls of the shell, and the pressure relief channel obliquely connects the oil inlet and the oil outlet.

4. The internal gear pump with a pressure relief channel according to claim 1, characterized in that: There are at least two pressure relief channels, and both ends of the two pressure relief channels are connected to the corresponding high-pressure chamber and low-pressure chamber respectively.

5. An internal gear pump with a pressure relief channel according to claim 4, characterized in that: The directions of both ends of the pressure relief channel are the same as the axial direction of the gear shaft. One end of the pressure relief channel is provided with an opening on the axial side wall, and the other end of the pressure relief channel is provided with an opening on the side wall of the low-pressure chamber.

6. An internal gear pump with a pressure relief channel according to any one of claims 2 to 5, characterized in that: The middle section of the pressure relief channel has a narrow hole.

Images