WO2021130858A1

WO2021130858A1 - Rotary pump

Info

Publication number: WO2021130858A1
Application number: PCT/JP2019/050625
Authority: WO
Inventors: 翔一高田; 真人魚住; 誠中林; 小林　英一; 一秋池田
Original assignee: 住友電工焼結合金株式会社; 住友電気工業株式会社
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2021-07-01
Also published as: DE112019008001T5; CN114585815A; US20220403841A1; JPWO2021130858A1

Abstract

A rotary pump equipped with a pump rotor which has a flat lateral rotor surface facing the axial direction, also equipped with a housing main body which has an axial-direction opening and a flat flange surface formed around the opening, and rotatably houses the pump rotor in the opening in a manner such that the lateral rotor surface and the flange surface are aligned in the same plane, and also equipped with a cover member which has a flat contact surface pressed against and secured to the flange surface by being bolted thereto and a flat sliding guide surface which slides on and guides the lateral rotor surface, wherein the cover member is formed from a crosslinked fluorine resin and a metal body, the metal body is provided with the contact surface and a recess which recesses in the axial direction relative to the contact surface in a region which corresponds to the sliding guide surface, and the crosslinked fluorine resin fills the recess interior in a manner such that the sliding guide surface is formed in the same plane as is the contact surface.

Description

Rotary pump

This disclosure relates to a rotary pump.

A rotary pump described in Patent Document 1 is known as a rotary pump that sucks and discharges a fluid by rotating a pump rotor. The rotary pump of Patent Document 1 has a pump rotor and a housing that rotatably accommodates the pump rotor.

Generally, a clearance is set between the housing and the sliding surface of the pump rotor to allow the pump rotor to rotate. If this clearance is large, the amount of fluid leakage increases and the discharge amount of the pump decreases. Therefore, it is preferable that the clearance between the housing and the sliding surface of the pump rotor is small. However, if this clearance is made too small, there is a problem that seizure easily occurs between the housing and the pump rotor. Therefore, the clearance between the housing and the sliding surface of the pump rotor is usually set to a size of several tens of μm or more.

Here, the applicant of the present application has developed a rotary pump capable of setting the clearance between the housing and the sliding surface of the pump rotor to be extremely small while preventing seizure between the housing and the pump rotor. As such a rotary pump, the one of Patent Document 2 is proposed.

The rotary pump of Patent Document 2 has a pump rotor and a housing for rotatably accommodating the pump rotor, and one or both of the housing and the pump rotor are coated with a crosslinked fluororesin. Since the crosslinked fluororesin has the characteristics of low friction coefficient and high wear resistance, when one or both of the housing and the pump rotor are coated with the crosslinked fluororesin, the sliding surface between the housing and the pump rotor is coated. Even when the clearance is set extremely small, seizure between the housing and the pump rotor can be prevented for a long period of time.

Japanese Unexamined Patent Publication No. 2014-47751 Japanese Unexamined Patent Publication No. 2014-173513

The rotary pump according to one aspect of the present disclosure is
A pump rotor with a flat rotor side facing the axis,
It has an axial opening and a flat flange surface formed around the opening, and the pump rotor can be rotated into the opening so that the rotor side surface and the flange surface are aligned on the same plane. The housing body to be accommodated and
A rotary pump including a flat mating surface that is pressed and fixed to the flange surface by tightening a bolt, and a cover member having a flat sliding guide surface that slides and guides the side surface of the rotor.
The cover member is formed of a crosslinked fluororesin and a metal body, and is formed of a crosslinked fluororesin and a metal body.
The metal body is provided with the mating surface and a recess in which a region corresponding to the sliding guide surface is recessed in the axial direction with respect to the mating surface.
The crosslinked fluororesin is provided by filling the recess so as to form the sliding guide surface on the same plane as the mating surface.
It is a rotary pump.

FIG. 1 is an exploded perspective view of the rotary pump according to the first embodiment of the present disclosure. FIG. 2 is a front view of the rotary pump of FIG. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. FIG. 5 is an enlarged view of the vicinity of the pump rotor of FIG. FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. FIG. 7 is an explanatory view of the manufacturing process of the side cover shown in FIG. FIG. 8 is an exploded perspective view of the rotary pump according to the second embodiment of the present disclosure. FIG. 9 is an enlarged cross-sectional view showing the rotary pump of FIG. 8 corresponding to FIG. FIG. 10 is an exploded perspective view of the rotary pump according to the third embodiment of the present disclosure. FIG. 11 is an enlarged cross-sectional view showing the rotary pump of FIG. 10 corresponding to FIG. FIG. 12 is a diagram showing a rotary pump according to a fourth embodiment of the present disclosure corresponding to FIG. FIG. 13 is a cross-sectional view taken along the line XIII-XIII of FIG. FIG. 14 is an enlarged view of the vicinity of the pump rotor of FIG.

[Issues to be solved by this disclosure]
As in Patent Document 2, the inventors of the present application have in-house developed a rotary pump in which at least one of the housing and the pump rotor is coated with a crosslinked fluororesin, and as such a rotary pump, the housing is crosslinked with fluoropolymer. We considered mass-producing resin-coated products.

Here, the housing is composed of a housing body and a cover member fixed to the housing body with bolts. The housing body has an axial opening and a flat flange surface formed around the opening, in which the pump rotor is rotatably housed. The cover member is a flat mating surface that is fixed by pressing it against the flange surface around the opening of the housing body by tightening bolts, and a flat slide that slides and guides the flat axial side surface (rotor side surface) of the pump rotor. It has a dynamic guide surface. The mating surface and the sliding guide surface are continuous flat surfaces.

Then, the inventors crosslink one surface of the metal cover member (that is, a continuous flat surface including a mating surface with the housing body and a sliding guide surface for sliding guide the rotor side surface of the pump rotor). A prototype coated with a resin film was manufactured in-house, and the cover member of the prototype was fixed to the housing body containing the pump rotor with bolts, and when the pump performance was evaluated, the pump rotor was driven to rotate. It was found that the torque for this may be larger than expected.

Therefore, as a result of the inventors investigating the cause of the torque for rotationally driving the pump rotor becoming larger than expected, the following was found. That is, when the cover member is fixed to the housing body with a bolt, the tightening force of the bolt compresses and deforms the crosslinked fluororesin film provided on the mating surface of the cover member with the housing body. The thickness of the crosslinked fluororesin film is reduced by about 1 μm to about 10 μm, and the position of the sliding guide surface of the cover member is slightly displaced in the axial direction by that amount. As a result, the axial clearance between the cover member and the pump rotor is slightly smaller than the design value, and the pump rotor is rotationally driven, especially when the clearance size is set to an extremely small size of 20 μm or less. It was found that the torque for the pump tends to be larger than expected.

Therefore, when the sliding guide surface of the cover member with respect to the pump rotor is formed of crosslinked fluororesin and the cover member is fixed to the housing body with bolts, the axial clearance between the cover member and the pump rotor is accurately controlled. It is an object of the present invention to provide a rotary pump capable of providing a rotary pump.

[Effect of the present disclosure]
According to the present disclosure, when the sliding guide surface of the cover member with respect to the pump rotor is formed of crosslinked fluororesin and the cover member is bolted to the housing body, the axial clearance between the cover member and the pump rotor Can be managed accurately.

[Explanation of Embodiments of the present disclosure]
(1) The rotary pump according to one aspect of the present disclosure is
A pump rotor with a flat rotor side facing the axis,
It has an axial opening and a flat flange surface formed around the opening, and the pump rotor can be rotated into the opening so that the rotor side surface and the flange surface are aligned on the same plane. The housing body to be accommodated and
A rotary pump including a flat mating surface that is pressed and fixed to the flange surface by tightening a bolt, and a cover member having a flat sliding guide surface that slides and guides the side surface of the rotor.
The cover member is formed of a crosslinked fluororesin and a metal body, and is formed of a crosslinked fluororesin and a metal body.
The metal body is provided with the mating surface and a recess in which a region corresponding to the sliding guide surface is recessed in the axial direction with respect to the mating surface.
The crosslinked fluororesin is provided by filling the recess so as to form the sliding guide surface on the same plane as the mating surface.
It is a rotary pump.
In this way, since the sliding guide surface of the cover member with respect to the pump rotor is formed of crosslinked fluororesin, even when the clearance between the cover member and the pump rotor is set to be extremely small, the cover member and the pump rotor It is possible to prevent seizure during a long period of time. Since the mating surface of the cover member to the housing body is provided on the metal body constituting the cover member, the tightening force of the bolt can be supported by the metal body portion with rigidity, and the cover member slides. It is possible to prevent the position of the guide surface from being displaced in the axial direction due to the tightening force of the bolt. Therefore, when the cover member is bolted to the housing body, it is possible to accurately manage the axial clearance between the cover member and the pump rotor.
(2) It is preferable that the cover member adopts a flat plate-shaped side cover that is sandwiched and fixed between the housing body and the cover body arranged so as to face the flange surface of the housing body.
In this way, the rotary pump according to one aspect of the present disclosure can be obtained by additionally incorporating a flat plate-shaped side cover between the housing body and the cover member of the existing rotary pump.
(3) The recess also includes a region corresponding to a part of the mating surface so that the crosslinked fluororesin filled in the recess contacts the flange surface in a continuous annular region around the opening. It is preferable to use one having a shape recessed in the axial direction including the one.
In this way, the crosslinked fluororesin filled in the recesses comes into contact with the flange surface in a continuous annular region around the opening of the housing body, so that the crosslinked fluororesin between the cover member and the contact surface of the housing body is crosslinked. It is possible to prevent fluid leakage by sealing with resin. Moreover, since the crosslinked fluororesin constituting the mating surface is continuous with the crosslinked fluororesin constituting the sliding guide surface, the manufacturing cost can be kept low.
(4) The mating surface and the sliding guide surface can be a continuous finished surface having a surface roughness of _{10-point average roughness Rz JIS 6.3 μm or less.}
In this way, the mating surface and the sliding guide surface can be finished at the same time, so that the cost is low. Further, since the surface roughness of the mating surface and the sliding guide surface is Rz _JIS 6.3 μm or less, it is possible to control the axial clearance between the cover member and the pump rotor with extremely high accuracy.
(5) The pump rotor has an inner rotor having a plurality of outer teeth on the outer circumference and a plurality of inner teeth rotatably supported around a position eccentric from the center of the inner rotor and meshing with the outer teeth. It can be configured with an annular outer rotor.
(6) The pump rotor can be composed of a rotor body having a plurality of vane accommodating grooves on the outer periphery and a plurality of vanes accommodated in the plurality of vane accommodating grooves so as to be slidable in the radial direction.

[Details of Embodiments of the present disclosure]
Specific examples of the rotary pump according to the embodiment of the present disclosure will be described below with reference to the drawings. It should be noted that the present invention is not limited to these examples, and is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

1 to 6 show the rotary pump according to the first embodiment of the present disclosure. The rotary pump includes a pump rotor 2 that is rotationally driven by a rotary shaft 1, a housing body 3 that houses the pump rotor 2, and a first cover body 4a and a first cover body 4a that are arranged on one side of the housing body 3 in the axial direction. The side cover 5a and the second cover main body 4b and the second side cover 5b arranged on the other side in the axial direction of the housing main body 3 are provided.

As shown in FIGS. 1 and 4, the pump rotor 2 is an inner rotor 7 having a plurality of outer teeth 6 on the outer circumference and an annular outer rotor 9 having a plurality of inner teeth 8 meshing with the outer teeth 6 on the inner circumference. It is configured. The inner rotor 7 and the outer rotor 9 are rotatably housed in the axial opening 10 formed in the housing body 3.

As shown in FIG. 3, the inner rotor 7 is formed with a shaft hole 11 into which the rotating shaft 1 is inserted. The rotating shaft 1 and the shaft hole 11 are fitted so that the rotating shaft 1 and the inner rotor 7 rotate integrally. The fitting of the rotating shaft 1 and the shaft hole 11 includes a two-sided width fitting as shown in the figure, a spline fitting, a keyway fitting, and a fitting with a tightening allowance between cylindrical surfaces (hard fitting and fitting). Fitting by press fitting) may be adopted.

As shown in FIG. 4, the outer rotor 9 has an outer peripheral cylindrical surface 12. The outer peripheral cylindrical surface 12 is fitted to the inner circumference of the opening 10 of the housing body 3 with a gap, and the outer rotor 9 is rotatably supported by the fitting. Here, the outer rotor 9 is rotatably supported around a position eccentric from the center position of the inner rotor 7 (that is, the rotation center position of the rotation shaft 1). When the inner rotor 7 is rotated, the outer rotor 9 rotates together with the inner rotor 7 due to the meshing of the inner teeth 8 and the outer teeth 6. The rotation direction of the inner rotor 7 is clockwise in the figure.

The number of internal teeth 8 of the outer rotor 9 is one more than the number of external teeth 6 of the inner rotor 7. A plurality of chambers 13 (spaces for accommodating fluids) partitioned by the outer teeth 6 and the inner teeth 8 are formed between the outer circumference of the inner rotor 7 and the inner circumference of the outer rotor 9. Here, the plurality of chambers 13 are configured so that their volumes change as the inner rotor 7 and the outer rotor 9 rotate. That is, the volume of the chamber 13 is maximized at the angle position where the center of the inner rotor 7 and the center of the outer rotor 9 are farthest (upper position in the figure), and the center of the inner rotor 7 and the center of the outer rotor 9 are closest to each other. It becomes smaller as it approaches (lower position in the figure). Therefore, when the inner rotor 7 and the outer rotor 9 rotate, the center of the inner rotor 7 and the center of the outer rotor 9 move from the farthest angle position to the closest angle position between the center of the inner rotor 7 and the center of the outer rotor 9. On the moving side (on the right side in the figure), the volume of the chamber 13 is reduced to discharge the fluid, while the inner rotor 7 is located at the closest angle between the center of the inner rotor 7 and the center of the outer rotor 9. On the side where the center of the outer rotor 9 and the center of the outer rotor 9 move toward the farthest angular position (on the left side in the figure), the volume of the chamber 13 gradually increases, so that a fluid suction action occurs.

As shown in FIG. 5, the inner rotor 7 has a flat first inner rotor side surface 14a facing one side in the axial direction (left side in the figure) and a flat first inner rotor 7 facing the other side in the axial direction (right side in the figure). It has 2 inner rotor side surfaces 14b. The first inner rotor side surface 14a and the second inner rotor side surface 14b are parallel planes facing opposite to each other in the axial direction. Further, the outer rotor 9 has a flat first outer rotor side surface 15a facing one side in the axial direction and a flat second outer rotor side surface 15b facing the other side in the axial direction. The first outer rotor side surface 15a and the second outer rotor side surface 15b are parallel planes facing opposite to each other in the axial direction.

Here, the axial width dimension of the inner rotor 7 from the first inner rotor side surface 14a to the second inner rotor side surface 14b is the outer rotor 9 from the first outer rotor side surface 15a to the second outer rotor side surface 15b. It is the same as the axial width dimension of. The first inner rotor side surface 14a and the first outer rotor side surface 15a are located on the same plane, and the second inner rotor side surface 14b and the second outer rotor side surface 15b are also located on the same plane. Both the inner rotor 7 and the outer rotor 9 are sintered bodies. The sintered body is a member obtained by heating a powder molded body obtained by compression molding an iron-based powder material with a mold at a high temperature below the melting point.

As shown in FIG. 3, the shaft hole 11 into which the rotating shaft 1 is inserted is a through hole that penetrates the inner rotor 7 in the axial direction. The rotating shaft 1 has a portion protruding from the inner rotor 7 on one side in the axial direction (left side in the drawing) and a portion protruding from the inner rotor 7 on the other side in the axial direction (right side in the drawing). It is inserted in the hole 11. The portion of the rotating shaft 1 protruding from the inner rotor 7 to one side in the axial direction is rotatably supported by the first bearing 16a attached to the first cover body 4a, and is rotatably supported from the inner rotor 7 of the rotating shaft 1. The portion protruding to the other side in the direction is rotatably supported by a second bearing 16b attached to the second cover body 4b. A portion of the rotating shaft 1 protruding from the inner rotor 7 to the other side in the axial direction (a portion supported by the second bearing 16b) is connected to a rotary driving device (electric motor or the like) (not shown).

As shown in FIG. 5, the first cover body 4a, the first side cover 5a, the housing body 3, the second side cover 5b, and the second cover body 4b are formed in the bolt insertion holes 17 formed in each member. A common bolt 18 is inserted and tightened in the axial direction with the bolt 18 to fix each other. Further, the first cover body 4a, the first side cover 5a, the housing body 3, the second side cover 5b, and the second cover body 4b have knock pins 20 common to the knock pin insertion holes 19 formed in the respective members. By inserting it, it is positioned in the direction perpendicular to the axis.

The housing body 3 has an opening 10 that opens to one side (left side in the drawing) and the other side (right side in the figure) in the axial direction, and a flat first flange formed around one side in the axial direction of the opening 10. It has a surface 21a and a flat second flange surface 21b formed around the other side of the opening 10 in the axial direction. The first flange surface 21a and the second flange surface 21b are parallel planes facing opposite to each other in the axial direction.

The first cover body 4a is arranged so as to face the first flange surface 21a of the housing body 3, and the first side cover 5a is sandwiched between the first cover body 4a and the housing body 3. .. The second cover body 4b is also arranged so as to face the second flange surface 21b of the housing body 3, and the second side cover 5b is sandwiched between the second cover body 4b and the housing body 3. ..

The first flange surface 21a is aligned with the first inner rotor side surface 14a and the first outer rotor side surface 15a. Further, the second flange surface 21b is aligned with the second inner rotor side surface 14b and the second outer rotor side surface 15b on the same plane. Here, the axial width dimension of the inner rotor 7 and the outer rotor 9 is slightly smaller than the axial width dimension of the housing body 3, and the difference is set to 20 μm or less (preferably 15 μm or less, more preferably 10 μm or less). Has been done.

The first side cover 5a and the second side cover 5b have a symmetrical configuration with the housing body 3 in between. Therefore, the first side cover 5a will be described, and the description of the second side cover 5b will be omitted by adding the same code or a code in which the last alphabet a is replaced with b in the corresponding portion.

The first side cover 5a slides a flat mating surface 22 fixed by pressing against the first flange surface 21a by tightening a bolt 18, a first inner rotor side surface 14a, and a first outer rotor side surface 15a. It has a flat sliding guide surface 23 for dynamic guidance.

The first side cover 5a is a flat plate-like member having a uniform thickness of 5 mm or less (preferably 4 mm or less). The first side cover 5a is formed of a crosslinked fluororesin 24 and a metal body 25. As the material of the metal body 25, a steel material or an aluminum alloy can be adopted. The metal body 25 is provided with a mating surface 22 made of metal and a recess 26 having a region corresponding to the sliding guide surface 23 recessed in the axial direction with respect to the mating surface 22. The recess 26 is a flat recess having a constant depth over the entire area. The depth of the recess 26 can be set to 0.5 mm or less (preferably 0.3 mm or less, more preferably 0.2 mm or less). The recess 26 has a contour that includes the contour of the opening 10 of the housing body 3 inside (in the figure, a circular contour having a diameter larger than the circle forming the contour of the opening 10). The recess 26 is filled with a crosslinked fluororesin 24, and the crosslinked fluororesin 24 forms a sliding guide surface 23 on the same plane as the mating surface 22. The mating surface 22 and the sliding guide surface 23 are continuous finished surfaces having a surface roughness of _{10-point average roughness Rz JIS} 6.3 μm or less (preferably Rz _{JIS 3.2 μm or less).}

Here, the ten-point average roughness Rz _JIS is referred to as "Annex JA (Reference)" of Japanese Industrial Standard JIS B0601: 2013 "Geometric characteristic specifications (GPS) of products-Surface texture: Contour curve method-Terms, definitions and surface texture parameters". ) Ten-point average roughness ”is a parameter specified. That is, the ten-point average roughness Rz _JIS extracts only the reference length from the roughness curve in the direction of the average line, and in this extracted portion, the average of the mountain heights from the highest mountain peak to the fifth mountain height and the highest. It is the sum of the average of the valley depths from the deepest valley bottom to the fifth in the deepest order.

The crosslinked fluororesin 24 is obtained by cross-linking between the molecules of the chain polymer constituting the fluororesin, and has a low friction coefficient equivalent to that of a general fluororesin (non-crosslinked fluororesin), but is generally used. It has extremely high wear resistance compared to fluororesin.

As the fluororesin to be crosslinked, polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) and the like can be adopted. .. It is preferable to use crosslinked PTFE as the crosslinked fluororesin 24. When the crosslinked PTFE is adopted, the crosslinked PTFE has a particularly low coefficient of friction among the above-mentioned fluororesins and is excellent in wear resistance, so that the crosslinked PTFE hardly wears and the pump efficiency can be effectively improved.

The first side cover 5a can be formed, for example, as follows.

As shown in the upper part of FIG. 7, first, a recess 26 is formed on the surface of a plate-shaped metal body 25 having a constant thickness. Next, as shown in the middle figure of FIG. 7, a film of the crosslinked fluororesin 24 is formed on the surface of the metal body 25 on the side of the recess 26. At this time, the recess 26 is filled with the crosslinked fluororesin 24, and the periphery of the recess 26 is also covered with the crosslinked fluororesin 24. After that, as shown in the lower figure of FIG. 7, the crosslinked fluororesin 24 is ground until the metal around the recess 26 is exposed, and further, the metal around the recess 26 and the crosslinked fluororesin 24 in the recess 26 are ground. To do. Here, the surface of the metal around the recess 26 corresponds to the mating surface 22, and the surface of the crosslinked fluororesin 24 in the recess 26 corresponds to the sliding guide surface 23. The mating surface 22 and the sliding guide surface 23 formed in this way form a continuous finished surface having the same surface roughness.

Here, the film of the crosslinked fluororesin 24 shown in the middle figure of FIG. 7 can be formed, for example, as follows. First, a dispersion liquid in which fine particles of fluororesin (for example, PTFE) are dispersed in water is applied to the surface of the metal body 25 on the side of the recess 26. Next, the applied dispersion liquid is dried to form a layer of fine particle particles of fluororesin on the surface of the metal body 25 on the side of the recess 26. Subsequently, by heating the metal body 25 and the layer of the fluororesin fine particles to a temperature equal to or higher than the melting point of the fluororesin, the fluororesin fine particles are fired and the fluororesin fine particles are fused to each other. After that, by irradiating radiation (for example, an electron beam) in a predetermined high-temperature anoxic atmosphere, a covalent bond is generated between the chain polymers constituting the fluororesin, and the molecules of the chain polymer are intermolecular. To bridge. Further, the radiation irradiated at this time also causes a chemical bond between the molecule of the chain polymer constituting the fluororesin and the surface of the metal body 25, and the chemical bond causes the film of the crosslinked fluororesin 24 to be formed. It adheres to the metal body 25 with extremely high adhesion. In this way, the film of the crosslinked fluororesin 24 shown in the middle figure of FIG. 7 can be formed.

As shown in FIG. 6, the first side cover 5a includes a first suction port 30a that opens on a surface facing the first inner rotor side surface 14a and the first outer rotor side surface 15a, and a first suction port. A first discharge port 31a that opens from the port 30a at intervals in the circumferential direction is provided.

Similarly, the second side cover 5b has a second suction port 30b that opens on a surface facing the second inner rotor side surface 14b and the second outer rotor side surface 15b, and a circumference from the second suction port 30b. A second discharge port 31b that opens at intervals in the direction is provided.

As shown in FIG. 1, both the first suction port 30a and the first discharge port 31a are opened in an arc shape centered on the rotation shaft 1. Similarly, both the second suction port 30b and the second discharge port 31b are opened in an arc shape centered on the rotation shaft 1.

The first suction port 30a and the second suction port 30b are opened at symmetrical positions with the inner rotor 7 and the outer rotor 9 sandwiched between them in the same shape. As a result, the pressure received by the first inner rotor side surface 14a and the first outer rotor side surface 15a from the fluid in the first suction port 30a and the second inner rotor side surface 14b from the fluid in the second suction port 30b. The pressure received by the second outer rotor side surface 15b is balanced, and the inner rotor 7 and the outer rotor 9 are prevented from being tilted.

Similarly, the first discharge port 31a and the second discharge port 31b are also opened at symmetrical positions with the inner rotor 7 and the outer rotor 9 sandwiched between them in the same shape. As a result, the pressure received by the first inner rotor side surface 14a and the first outer rotor side surface 15a from the fluid in the first discharge port 31a and the second inner from the fluid in the second discharge port 31b. The pressure received by the rotor side surface 14b and the second outer rotor side surface 15b is balanced to prevent the inner rotor 7 and the outer rotor 9 from being tilted.

As shown in FIGS. 4 and 6, the first suction port 30a and the second suction port 30b pass through a communication passage 32 formed at a position separated from the opening 10 accommodating the pump rotor 2 of the housing body 3. Communicate with each other. Further, as shown in FIGS. 2 and 6, the first suction port 30a communicates with the suction port 33 opening on the outer surface of the first cover body 4a, and the first discharge port 31a is the first cover. It communicates with the discharge port 34 that opens on the outer surface of the main body 4a.

In the above rotary pump, as shown in FIG. 5, since the sliding guide surface 23 of the first side cover 5a and the second side cover 5b is formed of the crosslinked fluororesin 24, the first side cover 5a And the clearance between the second side cover 5b and the pump rotor 2 (that is, the inner width dimension between the sliding guide surface 23 of the first side cover 5a and the sliding guide surface 23 of the second side cover 5b). And the first side even when the size (difference from the axial width dimension of the inner rotor 7 or the outer rotor 9) is set to an extremely small size (20 μm or less, preferably 15 μm or less, more preferably 10 μm or less). It is possible to prevent seizure between the cover 5a and the second side cover 5b and the pump rotor 2 for a long period of time.

Further, in this rotary pump, when the first side cover 5a and the second side cover 5b are fixed to the housing body 3 with bolts 18, the sliding guide surface 23 is less likely to be displaced due to the tightening force of the bolts 18. , It is possible to accurately manage the axial clearance between the first side cover 5a and the second side cover 5b and the pump rotor 2 (inner rotor 7 or outer rotor 9).

That is, tentatively, the first side cover 5a and the second side cover 5b shown in FIG. 5 are attached to the entire one surface of the metal body 25 (that is, the sliding guide surface between the mating surface 22 to the housing body 3 and the pump rotor 2). Assuming that the entire continuous flat surface including the 23 is replaced with a side cover coated with a crosslinked fluororesin (at this time, the metal body 25 is not provided with the recess 26), the side cover is attached to the housing body 3 with a bolt 18. When fixing, the tightening force of the bolt 18 compresses and deforms the cross-linked fluororesin film provided on the mating surface 22 of the side cover to the housing body 3, and the compressive deformation causes the thickness of the cross-linked fluororesin film. Is reduced by about 1 μm to about 10 μm, and the position of the sliding guide surface 23 of the side cover is slightly displaced in the axial direction by that amount. For example, when four bolts 18 are tightened with a torque of 11 Nm each, a crosslinked fluororesin film having a thickness of 50 μm becomes thinner by about 1.6 μm due to compressive deformation due to the tightening force of the bolts 18 and becomes 150 μm. A film of crosslinked fluororesin having a thickness of about 4.8 μm is thin, and a film of crosslinked fluororesin with a thickness of 250 μm is thinned by about 8.0 μm. As a result, the axial clearance between the side cover and the pump rotor 2 becomes slightly smaller than the design value, and especially when the clearance size is set to an extremely small size of 20 μm or less, the pump rotor 2 is operated. There is a problem that the torque for rotationally driving becomes larger than expected.

In response to this problem, in the rotary pump according to the embodiment of the present disclosure, the mating surfaces 22 of the first side cover 5a and the second side cover 5b to the housing body 3 have the first side cover 5a and the second side cover 5a and the second side cover 5a. Since it is provided on the metal body 25 constituting the side cover 5b, the tightening force of the bolt 18 can be supported by the portion of the metal body 25 with rigidity, and the first side cover 5a and the second side cover 5b can be supported. It is possible to prevent the position of the sliding guide surface 23 from being displaced in the axial direction due to the tightening force of the bolt 18. Therefore, when the first side cover 5a and the second side cover 5b are fixed to the housing body 3 with bolts 18, the axial direction between the first side cover 5a and the second side cover 5b and the pump rotor 2 It is possible to manage the clearance of the housing accurately.

Further, this rotary pump can obtain the rotary pump of the embodiment by adding the first side cover 5a and the second side cover 5b to the existing rotary pump, and is low cost.

Further, in this rotary pump, the recess 26 filled with the crosslinked fluororesin 24 is provided not in the first cover body 4a to which the first bearing 16a is attached, but in a metal body 25 separate from the first cover body 4a. Therefore, rather than providing the recess 26 for directly filling the crosslinked fluororesin 24 on the surface of the first cover body 4a and filling the crosslinked fluororesin 24, the recess 26 is processed and the crosslinked fluororesin 24 is filled. Is easy. Similarly, since the recess 26 filled with the crosslinked fluororesin 24 is provided not in the second cover body 4b to which the second bearing 16b is attached, but in the metal body 25 separate from the second cover body 4b. , It is easier to process the recess 26 and fill the crosslinked fluororesin 24 than to directly provide the recess 26 for filling the crosslinked fluororesin 24 on the surface of the second cover body 4b and fill the crosslinked fluororesin 24. ing.

Further, in this rotary pump, the mating surface 22 and the sliding guide surface 23 are finished at the same time, so that the mating surface 22 and the sliding guide surface 23 are made to have a ten-point average roughness Rz _JIS 6.3 μm or less (preferably Rz). _{Since it is a} continuous finished surface with a surface roughness of JIS 3.2 μm or less), the cost is low. Further, since the surface roughness of the mating surface 22 and the sliding guide surface 23 is Rz _JIS 6.3 μm or less (preferably Rz _JIS 3.2 μm or less), the first side cover 5a, the second side cover 5b, and the pump rotor Clearance between 2 (that is, the inner width dimension between the sliding guide surface 23 of the first side cover 5a and the sliding guide surface 23 of the second side cover 5b, and the inner rotor 7 or the outer rotor 9 It is possible to manage the difference from the width dimension in the axial direction) with extremely high accuracy.

8 and 9 show the rotary pump according to the second embodiment of the present disclosure. In the second embodiment, only the configurations of the first side cover 5a and the second side cover 5b are different from those of the first embodiment, and the other configurations are the same as those of the first embodiment. Therefore, the parts corresponding to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The first side cover 5a slides a flat mating surface 22 fixed by pressing against the first flange surface 21a by tightening a bolt 18, a first inner rotor side surface 14a, and a first outer rotor side surface 15a. It has a flat sliding guide surface 23 for dynamic guidance. The metal body 25 is provided with a mating surface 22 made of metal and a recess 26 having a region corresponding to the sliding guide surface 23 recessed in the axial direction with respect to the mating surface 22. The recess 26 is formed on the mating surface 22 so that the crosslinked fluororesin 24 filled in the recess 26 comes into contact with the first flange surface 21a in a continuous annular region around the opening 10 of the housing body 3. It has a shape recessed in the axial direction including a part corresponding to the region. That is, in the first side cover 5a, a part of the mating surface 22 (a portion surrounding the periphery of the bolt insertion hole 17) is formed in the metal body 25, and the remaining portion of the mating surface 22 is filled in the recess 26. It is made of fluororesin 24. The second side cover 5b is also configured in the same manner as the first side cover 5a.

In this rotary pump, the crosslinked fluororesin 24 filled in the recess 26 contacts the first flange surface 21a and the second flange surface 21b in an annular region that is continuous without interruption around the opening 10 of the housing body 3. Therefore, it is possible to seal the contact surfaces between the first side cover 5a and the second side cover 5b and the housing body 3 with the crosslinked fluororesin 24 to prevent fluid leakage. Moreover, since the crosslinked fluororesin 24 constituting the mating surface 22 is continuous with the crosslinked fluororesin 24 forming the sliding guide surface 23, the manufacturing cost can be kept low.

10 and 11 show the rotary pump according to the third embodiment of the present disclosure. The parts corresponding to the above embodiments are designated by the same reference numerals, and the description thereof will be omitted.

The rotary pump includes a pump rotor 2 that is rotationally driven by a rotary shaft 1, a housing body 3 that houses the pump rotor 2, and a first cover that is arranged on one side (left side in the figure) of the housing body 3 in the axial direction. It has a main body 4a and a second cover main body 4b arranged on the other side (right side in the drawing) of the housing main body 3 in the axial direction.

As shown in FIG. 11, in the first cover body 4a, the housing body 3, and the second cover body 4b, a common bolt 18 is inserted into a bolt insertion hole 17 formed in each member, and the bolt 18 is used in the axial direction. They are fixed to each other by tightening. Further, the first cover body 4a, the housing body 3, and the second cover body 4b are positioned in the direction perpendicular to the axis by inserting a common knock pin 20 into the knock pin insertion holes 19 formed in each member.

The first cover body 4a slides a flat mating surface 22 fixed by pressing against the first flange surface 21a by tightening bolts 18, a first inner rotor side surface 14a, and a first outer rotor side surface 15a. It has a flat sliding guide surface 23 for dynamic guidance.

The first cover body 4a is formed of a crosslinked fluororesin 24 and a metal body 25. As the material of the metal body 25, a steel material or an aluminum alloy can be adopted. The metal body 25 is provided with a mating surface 22 made of metal and a recess 26 having a region corresponding to the sliding guide surface 23 recessed in the axial direction with respect to the mating surface 22. The recess 26 is filled with a crosslinked fluororesin 24, and the crosslinked fluororesin 24 forms a sliding guide surface 23 on the same plane as the mating surface 22. The second cover body 4b is also configured in the same manner as the first cover body 4a.

In this rotary pump as well, as in each of the above embodiments, the sliding guide surface 23 of the first cover body 4a and the second cover body 4b is formed of the crosslinked fluororesin 24, so that the first cover body 4a And the clearance between the second cover body 4b and the pump rotor 2 (that is, the inner width dimension between the sliding guide surface 23 of the first cover body 4a and the sliding guide surface 23 of the second cover body 4b). When the difference between the inner rotor 7 and the outer rotor 9 in the axial width dimension) is set to an extremely small size (20 μm or less, preferably 15 μm or less, more preferably 10 μm or less), the first cover main body It is possible to prevent seizure between the 4a and the second cover body 4b and the pump rotor 2 for a long period of time.

Further, in this rotary pump, the mating surface 22 of the first cover body 4a and the second cover body 4b to the housing body 3 constitutes the first cover body 4a and the second cover body 4b. Since it is provided in, the tightening force of the bolt 18 can be supported by the portion of the metal body 25 with rigidity, and the position of the sliding guide surface 23 of the first cover body 4a and the second cover body 4b is the bolt. The tightening force of 18 can prevent the displacement in the axial direction. Therefore, when the first cover body 4a and the second cover body 4b are fixed to the housing body 3 with bolts 18, the axial direction between the first cover body 4a and the second cover body 4b and the pump rotor 2 It is possible to manage the clearance of the housing accurately.

12 to 14 show the rotary pump according to the fourth embodiment of the present disclosure. In the fourth embodiment, only the configuration of the pump rotor 2 is different from the first embodiment, and the other configurations are the same as those in the first embodiment. Therefore, the parts corresponding to the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIGS. 12 and 13, the pump rotor 2 has a rotor main body 36 having a plurality of vane accommodating grooves 35 on the outer periphery, and a plurality of vanes slidably accommodated in the plurality of vane accommodating grooves 35, respectively. It is composed of 37. The radial outer end of the vane 37 is in sliding contact with the inner circumference of the cam ring 38 provided in the housing body 3. Inside the cam ring 38, an opening 10 for rotatably accommodating the pump rotor 2 is formed. A plurality of chambers 39 (spaces for accommodating fluids) partitioned by vanes 37 are formed between the outer circumference of the rotor body 36 and the inner circumference of the cam ring 38. The inner circumference of the cam ring 38 is configured so that the volume of each chamber 39 changes as the rotor body 36 rotates, and the fluid discharge action due to the volume reduction of the chamber 39 and the volume of the chamber 39 gradually increase. As a result, the inhalation action of the fluid occurs.

As shown in FIG. 14, the first side cover 5a has a flat mating surface 22 that is pressed and fixed to the first flange surface 21a by tightening a bolt 18 (see FIG. 12), a rotor body 36, and a vane. It has a flat sliding guide surface 23 that slides and guides a flat side surface of 37 that faces the axial direction. The second side cover 5b is also configured in the same manner as the first side cover 5a.

Further, the inner circumference of the cam ring 38 is coated with a crosslinked fluororesin film 40. The axial width dimension of the rotor body 36 is the same as the axial width dimension of the vane 37.

In this rotary pump, as shown in FIG. 12, since the sliding guide surface 23 of the first side cover 5a and the second side cover 5b is formed of the crosslinked fluororesin 24, the first side cover 5a and the second side cover 5b The clearance between the second side cover 5b and the pump rotor 2 (that is, the inner width dimension between the sliding guide surface 23 of the first side cover 5a and the sliding guide surface 23 of the second side cover 5b). Even when the rotor body 36 and the vane 37 (difference from the axial width dimension) are set to an extremely small size (20 μm or less, preferably 15 μm or less, more preferably 10 μm or less), the first side cover 5a It is possible to prevent seizure between the second side cover 5b and the pump rotor 2 for a long period of time.

Further, in this rotary pump, the mating surface 22 of the first side cover 5a and the second side cover 5b with respect to the housing body 3 constitutes the first side cover 5a and the second side cover 5b. Since it is provided in, the tightening force of the bolt 18 can be supported by the portion of the metal body 25 with rigidity, and the position of the sliding guide surface 23 of the first side cover 5a and the second side cover 5b is the bolt. The tightening force of 18 can prevent the displacement in the axial direction. Therefore, when the first side cover 5a and the second side cover 5b are fixed to the housing body 3 with bolts 18, the shaft between the first side cover 5a and the second side cover 5b and the pump rotor 2 It is possible to accurately manage the clearance in the direction.

1 Rotating shaft 2 Pump rotor 3 Housing body 4a First cover body 4b Second cover body 5a First side cover 5b Second side cover 6 External teeth 7 Inner rotor 8 Internal teeth 9 Outer rotor 10 Opening 11 Shaft hole 12 Outer cylindrical surface 13 Chamber 14a First inner rotor side surface 14b Second inner rotor side surface 15a First outer rotor side surface 15b Second outer rotor side surface 16a First bearing 16b Second bearing 17 Bolt insertion hole 18 bolt 19 Knock pin insertion hole 20 Knock pin 21a First flange surface 21b Second flange surface 22 Alignment surface 23 Sliding guide surface 24 Cross-linked fluororesin 25 Metal body 26 Recess 30a First suction port 30b Second suction port 31a First Discharge port 31b Second discharge port 32 Continuous passage 33 Suction port 34 Discharge port 35 Vane accommodation groove 36 Rotor body 37 Vane 38 Cam ring 39 Chamber 40 Cross-linked fluororesin film

Claims

A pump rotor with a flat rotor side facing the axis,
It has an axial opening and a flat flange surface formed around the opening, and the pump rotor can be rotated into the opening so that the rotor side surface and the flange surface are aligned on the same plane. The housing body to be accommodated and
A rotary pump including a flat mating surface that is pressed and fixed to the flange surface by tightening a bolt, and a cover member having a flat sliding guide surface that slides and guides the side surface of the rotor.
The cover member is formed of a crosslinked fluororesin and a metal body, and is formed of a crosslinked fluororesin and a metal body.
The metal body is provided with the mating surface and a recess in which a region corresponding to the sliding guide surface is recessed in the axial direction with respect to the mating surface.
The crosslinked fluororesin is provided by filling the recess so as to form the sliding guide surface on the same plane as the mating surface.
Rotary pump.
The rotary pump according to claim 1, wherein the cover member is a flat plate-shaped side cover that is sandwiched and fixed between the housing body and the cover body arranged so as to face the flange surface of the housing body. ..
The recess includes a region corresponding to a part of the mating surface so that the crosslinked fluororesin filled in the recess contacts the flange surface in a continuous annular region around the opening. The rotary pump according to claim 1 or 2, which has a shape recessed in the direction.
The aspect according to any one of claims 1 to 3, wherein the mating surface and the sliding guide surface are continuous finished surfaces having a surface roughness of 10-point average roughness Rz JIS 6.3 μm or less. Rotary pump.
The pump rotor is rotatably supported around an inner rotor having a plurality of outer teeth on the outer circumference and a position eccentric from the center of the inner rotor, and has a plurality of internal teeth meshing with the outer teeth on the inner circumference. The rotary pump according to any one of claims 1 to 4, which is composed of the outer rotor of the above.
Claims 1 to 4 wherein the pump rotor is composed of a rotor main body having a plurality of vane accommodating grooves on the outer periphery and a plurality of vanes slidably accommodated in the plurality of vane accommodating grooves. The rotary pump according to any one item.