An internal gear pump

Abstract

The present invention provides an internal gear pump, which relates to the technical field of gear pumps, and comprises: an internal gear, an external gear ring, a front cover, a rear cover, a shaft sleeve, a pump body and a shaft, wherein the internal gear, the external gear ring and the shaft are motion components, the front cover, the rear cover and the shaft sleeve are friction components, and the pump body is a structural component. The motion component is made of tungsten carbide, an alloy material with high hardness and strength, the friction component is made of zirconium oxide, a ceramic material with high hardness and wear resistance, and the structural components with complex structures are made of stainless steel materials that are easy to process. Therefore, the internal gear pump provided by the present invention can reduce the processing cost under the premise of ensuring that product quality is not affected.

Description

Technical Field

[0001] The invention relates to the technical field of gear pumps, in particular to an internal gear pump. Background Art

[0002] The internal gear pump is a positive displacement pump, which consists of front and rear covers, an outer gear ring and an eccentrically placed internal gear. There is a difference in the number of teeth between the internal gear and the outer gear ring. During one rotation of the internal gear, a number of closed spaces with continuous volume expansion and contraction cycles are formed between the tooth tops of the internal gear and the tooth valleys of the outer gear ring. When the volume expands, a vacuum is generated in the pump suction chamber, sucking the liquid into the pump. When the volume decreases, pressure is generated in the pump discharge chamber, discharging the liquid out of the pump. The above process is repeated to complete the suction and discharge process of the pump.

[0003] In order to improve the working performance and life of the gear pump in the prior art, it is necessary to reduce the matching clearance in the pump as much as possible and improve the wear resistance of the working parts of the pump, which requires high-precision wear-resistant material parts. The industry mostly uses ceramic or cemented carbide materials, but due to the characteristics of high strength, high hardness and high brittleness of ceramic and cemented carbide, traditional machining methods such as turning, milling and drilling are difficult to meet the precision requirements. Initially, only grinding methods could be used for machining, and the structures that can accurately control the size are mostly the outer diameter, plate thickness, etc., which has limitations. With the development of mechanical processing technology, the processing techniques that can be used have also increased, such as chemical processing, electrical processing, optical processing, etc., but the processing cost and efficiency may not be superior to abrasive processing. In view of the need to strictly control the cost of water pump products to expand the application range of the market, the processing technology of ceramic and cemented carbide should try to use abrasive chips. However, the existing gear pumps, whether they are moving components, structural parts or fasteners, use ceramic or cemented carbide materials, which leads to extremely high processing costs for gear pumps. Summary of the invention

[0004] The object of the present invention is to provide an internal gear pump to solve the problems existing in the above-mentioned prior art and to reduce the processing cost without affecting the product quality.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides an internal meshing gear pump, comprising: an internal gear, an external gear ring, a front cover, a rear cover, a shaft sleeve, a pump body and a shaft, wherein the internal gear is arranged in the external gear ring and meshes with the teeth in the external gear ring, the shaft sleeve is sleeved on the outer periphery of the external gear ring, a receiving cavity for accommodating the internal gear, the external gear ring and the shaft sleeve is arranged in the pump body, the shaft sleeve is fixed in the receiving cavity, the external gear ring can rotate around its own axis in the shaft sleeve, the front cover and the rear cover are respectively arranged in the receiving cavity The outer gear ring and the inner gear are both in contact with the end surfaces of the front cover and the rear cover facing the accommodating cavity, one end of the shaft passes through the rear cover, extends into the accommodating cavity and is inserted into the shaft hole of the inner gear, and the other end is used for transmission connection with the driving device, and the shaft and the inner gear are relatively fixed along the circumferential direction; the inner gear, the outer gear ring and the shaft are all made of tungsten carbide, the bushing, the front cover and the rear cover are all made of zirconium oxide, and the pump body is made of stainless steel.

[0007] Preferably, a channel is provided in the pump body, the accommodating cavity is formed by part of the channel, the front cover and the rear cover are both provided in the channel, the outer circumferential surfaces of the front cover, the rear cover and the sleeve are all in close contact with the inner circumferential surface of the channel, and the outer circumferential surface of the sleeve is interference fit with the inner circumferential surface of the channel.

[0008] Preferably, both ends of the shaft are provided with a first limiting surface extending from the end toward the center of the shaft, the first limiting surface is parallel to the center line of the shaft, and the shaft hole of the internal gear is provided with a second limiting surface matching the first limiting surface, the second limiting surface extends from one end of the shaft hole to the other end, after one end of the shaft is inserted into the shaft hole, the first limiting surface is parallel to and in contact with the second limiting surface, and the first limiting surface at the other end of the shaft is used to match with the corresponding structure on the driving device.

[0009] Preferably, two first limiting surfaces are provided at both ends of the shaft, and two second limiting surfaces are also provided in the shaft hole.

[0010] Preferably, a sealing plug is further sleeved on the shaft, and the sealing plug is located in the channel on the side of the rear cover away from the accommodating chamber, and a first flange extending outward and perpendicular to the axial direction of the sealing plug is provided on the side of the sealing plug away from the rear cover, and a second flange matching with the first flange is provided in the channel on the side of the first flange facing the accommodating chamber, and the first flange abuts against the second flange.

[0011] Preferably, the front cover is provided with a fluid inlet and a fluid outlet communicated with the accommodating cavity.

[0012] Preferably, the pump body comprises a front sealing cap and a rear pump body, the outer diameters of the front cover, the shaft sleeve, the rear cover and the sealing plug become smaller in sequence, the front sealing cap and the rear pump body are respectively provided with a first sub-channel and a second sub-channel, the front cover is arranged in the first sub-channel, a third flange extending from the inner wall of the first sub-channel to the center line of the first sub-channel is arranged in the first sub-channel on the side of the front cover away from the accommodating chamber, the end surface of the third flange facing the front cover abuts against the front cover, a sealing ring groove is arranged on the end surface of the third flange facing the front cover, a sealing ring is arranged in the sealing ring groove, the shaft sleeve, the rear cover and the sealing plug are all arranged in the second sub-channel, one end of the rear pump body is embedded in one end of the front sealing cap, and a second sealing ring is arranged at the connection between the rear pump body and the front sealing cap.

[0013] Compared with the prior art, the present invention has achieved the following technical effects:

[0014] The internal gear pump provided by the present invention comprises: an internal gear, an external gear ring, a front cover, a rear cover, a shaft sleeve, a pump body and a shaft, wherein the internal gear, the external gear ring and the shaft are motion components, the front cover, the rear cover and the shaft sleeve are friction components, and the pump body is a structural component. Therefore, the motion component is made of tungsten carbide, an alloy material with high hardness and strength, the friction component is made of zirconium oxide, a ceramic material with high hardness and wear resistance, and the structural components with complex structures are made of stainless steel materials that are easy to process. The internal gear pump provided by the present invention can reduce the processing cost without affecting the product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A cross-sectional view of the internal gear pump provided by the present invention;

[0017] Figure 2 An appearance diagram of the internal gear pump provided by the present invention;

[0018] Figure 3 It is a schematic diagram of the structure after the shaft, internal gear, external gear ring and shaft sleeve are assembled;

[0019] Figure 4 It is a schematic diagram of the structure after the shaft, internal gear, external gear ring, front cover, rear cover, sealing plug and shaft sleeve are assembled;

[0020] Figure 5 It is a schematic diagram of the structure of the rear pump body and its internal components;

[0021] Figure 6 is a schematic diagram of the structure of the shaft;

[0022] In the figure: 1-pump body, 2-shaft, 3-sleeve, 4-external gear ring, 5-internal gear, 6-front cover, 7-rear cover, 8-sealing plug, 9-sealing ring groove, 11-rear pump body, 12-front sealing cap, 61-fluid inlet, 62-fluid outlet. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide an internal gear pump to solve the problems existing in the prior art and reduce the processing cost without affecting the product quality.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The present invention provides an internal gear pump, such as Figures 1 to 6As shown, it includes: an internal gear 5, an external gear ring 4, a front cover 6, a rear cover 7, a sleeve 3, a pump body 1 and a shaft 2. The internal gear 5 is arranged in the external gear ring 4 and meshes with the teeth in the external gear ring 4. The internal gear 5 is eccentrically arranged in the external gear ring 4. The sleeve 3 is sleeved on the outer periphery of the external gear ring 4. A receiving cavity for accommodating the internal gear 5, the external gear ring 4 and the sleeve 3 is provided in the pump body 1. The sleeve 3 is fixed in the receiving cavity. The external gear ring 4 can rotate around its own axis on the sleeve 3. The front cover 6 and the rear cover 7 are respectively arranged at both ends of the receiving cavity, and the external gear ring 4 and the internal gear 5 are both abutted on the end surfaces of the front cover 6 and the rear cover 7 facing the receiving cavity. The external gear ring 4 and the internal gear 5 can rotate relative to the front cover 6 and the rear cover 7. One end of the shaft 2 passes through the rear cover 7, extends into the receiving cavity and is inserted into the shaft hole of the internal gear 5, and the other end of the shaft 2 passes through the rear cover 7, extends into the receiving cavity and is inserted into the shaft hole of the internal gear 5. The end is used for transmission connection with the driving device, and the shaft 2 and the internal gear 5 are relatively fixed along the circumferential direction; the internal gear 5, the outer gear ring 4, and the shaft 2 are all made of tungsten carbide, the sleeve 3, the front cover 6 and the rear cover 7 are all made of zirconium oxide, and the pump body 1 is made of stainless steel. There is a difference in the number of teeth between the internal gear 5 and the outer gear ring 4. During the process of one rotation of the internal gear 5, a number of closed spaces with continuous expansion and contraction cycles of volume are formed between the tooth tops of the internal gear 5 and the tooth valleys of the outer gear ring 4. When the volume expands, a vacuum is generated at the pump suction chamber to suck the liquid into the pump. When the volume decreases, pressure is generated at the pump discharge chamber to discharge the liquid to the outside of the pump. The above process is repeated to complete the suction and discharge process of the pump. When in use, the driving device drives the shaft 2 to rotate, and the shaft 2 drives the internal gear 5 and the outer gear ring 4 to rotate to realize the suction and discharge process.

[0027] The internal gear pump provided by the present invention comprises: an internal gear 5, an outer gear ring 4, a front cover 6, a rear cover 7, a shaft sleeve 3, a pump body 1 and a shaft 2, wherein the internal gear 5, the outer gear ring 4 and the shaft 2 are motion components, the front cover 6, the rear cover 7 and the shaft sleeve 3 are friction components, and the pump body 1 is a structural component. Therefore, the motion component is made of tungsten carbide, an alloy material with high hardness and strength, the friction component is made of zirconium oxide, a ceramic material with high hardness and wear resistance, and the structural components with complex structures are made of stainless steel materials that are easy to process. Therefore, the internal gear pump provided by the present invention can reduce the processing cost without affecting the product quality.

[0028] Furthermore, a channel is provided in the pump body 1, and the accommodating cavity is formed by part of the channel. The front cover 6 and the rear cover 7 are both provided in the channel. The outer circumferential surfaces of the front cover 6, the rear cover 7 and the shaft sleeve 3 are in close contact with the inner circumferential surface of the channel, and the outer circumferential surface of the shaft sleeve 3 and the inner circumferential surface of the channel are interference fit. The assembly process is simple and easy to operate. The front cover 6 and the rear cover 7 are both circular, and the shaft sleeve 3 is in a circular shape. The circular and circular structures are simple to process.

[0029] Furthermore, both ends of the shaft 2 are provided with a first limit surface extending from the end toward the center of the shaft 2, and the first limit surface is parallel to the center line of the shaft 2. A second limit surface matching the first limit surface is provided in the shaft hole of the internal gear 5, and the second limit surface extends from one end of the shaft hole to the other end. After one end of the shaft 2 is inserted into the shaft hole, the first limit surface is parallel and in contact with the second limit surface, so that the shaft 2 drives the internal gear 5 to rotate, and the first limit surface at the other end of the shaft 2 is used to match with the corresponding structure on the driving device. Preferably, two first limit surfaces are provided at both ends of the shaft 2, and two second limit surfaces are also provided in the shaft hole. The above-mentioned limit surface structure is easier to process than the existing keyway structure, and the axial positioning of the shaft 2, the internal gear 5 and the outer gear ring 4 is achieved by matching with the front cover 6 and the rear cover 7.

[0030] Furthermore, a sealing flood-plug 8 is sleeved on the shaft 2. The sealing flood-plug 8 is located in a channel on a side of the rear cover 7 away from the accommodating chamber. A first flange extending outward and perpendicular to the axial direction of the sealing flood-plug 8 is provided on a side of the sealing flood-plug 8 away from the rear cover 7. A second flange matching the first flange is provided in a channel on a side of the first flange facing the accommodating chamber. The first flange abuts against the second flange, and the sealing flood-plug 8 serves as a shaft dynamic seal.

[0031] Furthermore, a fluid inlet 61 and a fluid outlet 62 which are in communication with the accommodating cavity are provided on the front cover 6 . The fluid inlet 61 is used for sucking liquid, and the fluid outlet 62 is used for discharging liquid.

[0032] Further, the pump body 1 includes a front sealing cap 12 and a rear pump body 11, the outer walls of the front sealing cap 12 and the rear pump body 11 are on the same cylindrical surface, the outer diameters of the front cover 6, the shaft sleeve 3, the rear cover 7 and the sealing plug 8 are successively smaller, and the front sealing cap 12 and the rear pump body 11 are respectively provided with a first sub-channel and a second sub-channel, the front cover 6 is provided in the first sub-channel, and the first sub-channel on the side of the front cover 6 away from the accommodating chamber is provided with a third flange extending from the inner wall of the first sub-channel to the center line of the first sub-channel, and the end surface of the third flange facing the front cover 6 abuts against the front cover 6, a sealing ring groove 9 is arranged on the end surface of the third flange facing the front cover 6, a sealing ring is arranged in the sealing ring groove 9, the shaft sleeve 3, the rear cover 7 and the sealing plug 8 are all arranged in the second sub-channel, one end of the rear pump body 11 is inserted into one end of the front sealing cap 12, and a second sealing ring is arranged at the connection between the rear pump body 11 and the front sealing cap 12. As shown in the figure, the pump body 1 is arranged as a split structure to facilitate the processing of the channel in the pump body 1, so that the inner wall of the channel can cooperate with the various moving components and friction components therein, and the sealing ring is a static seal.

[0033] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An internal gear pump, characterized in that: include: An internal gear, an external gear ring, a front cover, a rear cover, a sleeve, a pump body and a shaft, wherein the internal gear is arranged in the external gear ring and meshes with the teeth in the external gear ring, the sleeve is sleeved on the outer periphery of the external gear ring, a receiving cavity for receiving the internal gear, the external gear ring and the sleeve is arranged in the pump body, the sleeve is fixed in the receiving cavity, the external gear ring can rotate around its own axis in the sleeve, the front cover and the rear cover are respectively arranged at the two ends of the receiving cavity, and the external gear ring and the internal gear are both in contact with the end surfaces of the front cover and the rear cover facing the receiving cavity, one end of the shaft passes through the rear cover, extends into the receiving cavity and is inserted into The shaft hole of the internal gear has the other end used for transmission connection with the driving device, and the shaft and the internal gear are relatively fixed along the circumferential direction; the internal gear, the outer gear ring and the shaft are all made of tungsten carbide, the shaft sleeve, the front cover and the rear cover are all made of zirconium oxide, and the pump body is made of stainless steel; a channel is provided in the pump body, the accommodating cavity is formed by part of the channel, the front cover and the rear cover are both provided in the channel, the outer circumferential surfaces of the front cover, the rear cover and the shaft sleeve are in close contact with the inner circumferential surface of the channel, and the outer circumferential surface of the shaft sleeve is interference fit with the inner circumferential surface of the channel; a sealing plug is also sleeved on the shaft, and the sealing The universal plug is located in the channel on the side of the rear cover away from the accommodating chamber, and a first flange extending outward and perpendicular to the axial direction of the universal plug is provided on the side of the sealing universal plug away from the rear cover. A second flange matching with the first flange is provided in the channel on the side of the first flange facing the accommodating chamber, and the first flange abuts against the second flange. The pump body includes a front sealing cap and a rear pump body, and the outer diameters of the front cover, the shaft sleeve, the rear cover and the universal plug are successively reduced. The front sealing cap and the rear pump body are respectively provided with a first sub-channel and a second sub-channel, and the front cover is provided in the first sub-channel. A third flange extending from the inner wall of the first sub-channel to the center line of the first sub-channel is arranged in the first sub-channel on the side of the front cover away from the accommodating chamber, the end surface of the third flange facing the front cover abuts against the front cover, a sealing ring groove is arranged on the end surface of the third flange facing the front cover, a sealing ring is arranged in the sealing ring groove, the shaft sleeve, the rear cover and the sealing plug are all arranged in the second sub-channel, one end of the rear pump body is inserted into one end of the front sealing cap, and a second sealing ring is arranged at the connection between the rear pump body and the front sealing cap; a fluid inlet and a fluid outlet communicated with the accommodating chamber are arranged on the front cover.

2. The internal gear pump according to claim 1, characterized in that: Both ends of the shaft are provided with a first limiting surface extending from the end toward the center of the shaft, and the first limiting surface is parallel to the center line of the shaft. A second limiting surface matching the first limiting surface is provided in the shaft hole of the internal gear, and the second limiting surface extends from one end of the shaft hole to the other end. After one end of the shaft is inserted into the shaft hole, the first limiting surface is parallel to and in contact with the second limiting surface, and the first limiting surface at the other end of the shaft is used to match with the corresponding structure on the driving device.

3. The internal gear pump according to claim 2, characterized in that: Two first limit surfaces are provided at both ends of the shaft, and two second limit surfaces are also provided in the shaft hole.

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