Oscillating gear pump and refrigeration system

Abstract

The utility model provides a kind of cycloidal gear pump and refrigeration system, cycloidal gear pump includes: pump body;Outer rotor, rotatably mounted in the inside of pump body, outer rotor includes multiple inner teeth;Inner rotor, rotatably mounted in the inside of pump body, and inner rotor is located in the inside of outer rotor, inner rotor is eccentrically arranged relative to outer rotor, inner rotor includes multiple outer teeth, the number of outer tooth is less than the number of inner tooth, outer rotor is engaged with inner rotor;Multiple rollers, roller is installed between the outer circumferential surface of outer rotor and the inner circumferential surface of pump body, outer circumferential surface and the inner circumferential surface of pump body are all contacted with roller, multiple rollers are spaced distribution along the circumference of outer rotor, when outer rotor rotates relative to pump body, roller rolls. The cycloidal gear pump can reduce the friction and wear between outer rotor and pump body, improve the performance and life of cycloidal gear pump.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration technology, and in particular to a cycloidal gear pump and refrigeration system. Background Technology

[0002] Cycloidal gear pumps (internal meshing cycloidal gear pumps) are widely used in the refrigerant pump field of air conditioning systems due to their advantages such as compact structure, low flow pulsation, and low noise. They can be used to transport refrigerant. In existing technology, a cycloidal gear pump includes a pump body, an outer rotor, and an inner rotor. The inner rotor meshes with the outer rotor, and the outer rotor is installed in a circular hole in the pump body. When the outer rotor rotates, its outer circumferential surface directly contacts and rubs against the wall of the circular hole in the pump body.

[0003] Friction between the outer rotor and the pump body reduces the mechanical efficiency of the cycloidal gear pump, resulting in power waste and affecting its performance. This friction also leads to severe wear on both the outer rotor and the pump body, impacting the pump's lifespan. Utility Model Content

[0004] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a cycloidal gear pump that can reduce friction and wear between the outer rotor and the pump body, thereby improving the performance and lifespan of the cycloidal gear pump.

[0005] This utility model also proposes a refrigeration system including the above-mentioned cycloidal gear pump.

[0006] A cycloidal gear pump according to a first aspect of the present invention includes: a pump body; an outer rotor rotatably mounted inside the pump body, the outer rotor including a plurality of internal teeth; an inner rotor rotatably mounted inside the pump body, the inner rotor being located inside the outer rotor, the inner rotor being eccentrically arranged relative to the outer rotor, the inner rotor including a plurality of external teeth, the number of external teeth being less than the number of internal teeth, the outer rotor meshing with the inner rotor; and a plurality of rollers mounted between the outer peripheral surface of the outer rotor and the inner peripheral surface of the pump body, both the outer peripheral surface and the inner peripheral surface of the pump body being in contact with the rollers, the plurality of rollers being circumferentially spaced along the outer rotor, the rollers rolling when the outer rotor rotates relative to the pump body.

[0007] The cycloidal gear pump according to the embodiments of the present invention has at least the following beneficial effects: In existing technology, the outer circumferential surface of the outer rotor directly contacts the wall of the circular hole at the center of the pump body, forming a sliding friction pair. This sliding friction between the outer rotor and the pump body generates a large frictional torque, resulting in significant frictional losses, reduced mechanical efficiency of the cycloidal gear pump, and wasted power. The high friction between the outer rotor and the pump body makes them prone to wear. After wear occurs, the gap between the outer rotor and the pump body may become uneven, causing the outer rotor to jam or vibrate abnormally during rotation, thus reducing the reliability and service life of the cycloidal gear pump. Furthermore, the sliding friction pair is highly sensitive to contaminants in the fluid flowing through the cycloidal gear pump; tiny particles in the fluid exacerbate wear.

[0008] In this embodiment of the cycloidal gear pump, rollers are provided between the outer circumferential surface of the outer rotor and the inner circumferential surface of the pump body, and the outer circumferential surface of the outer rotor does not directly contact the inner circumferential surface of the pump body. The friction between the outer rotor and the rollers is rolling friction, and the friction between the pump body and the rollers is rolling friction. Since rolling friction is less than sliding friction, this embodiment helps to reduce the friction experienced by the outer rotor and the pump body, thereby reducing the wear of the outer rotor and the pump body and improving the performance, reliability, and lifespan of the cycloidal gear pump.

[0009] According to some embodiments of the present invention, the cycloidal gear pump further includes a bearing ring, which is installed in the pump body and surrounds the outer periphery of the outer rotor, and the roller is rotatably installed on the bearing ring.

[0010] According to some embodiments of the present invention, the pump body defines an annular mounting groove, and the bearing ring is located within the mounting groove.

[0011] According to some embodiments of this utility model, in the radial direction of the pump body, the maximum wall thickness of the pump body is A, the depth of the mounting groove is B, and A / 4≤B≤A / 3.

[0012] According to some embodiments of the present invention, the high-pressure side end face of the pump body is provided with a plurality of through holes, the through holes are connected to the mounting groove, and the plurality of through holes are distributed at intervals along the circumference of the pump body.

[0013] According to some embodiments of the present invention, the pump body includes a main body and a boss portion, both of which are annular. The boss portion is connected to the main body and protrudes inward relative to the main body. In the axial direction of the pump body, the boss portion is located at one end of the main body. The inner circumferential surface of the main body and the inner end face of the boss portion both serve as part of the wall surface of the mounting groove. The cycloidal gear pump also includes a retaining ring, which is engaged in the mounting groove. The inner end face of the retaining ring abuts against one end face of the bearing ring, and the retaining ring abuts against the other end face of the bearing ring to prevent the bearing ring from disengaging from the mounting groove.

[0014] According to some embodiments of the present invention, the fixing ring is elastic and the fixing ring is an open ring shape.

[0015] According to some embodiments of this utility model, the number of rollers is N, where 40 ≤ N ≤ 60.

[0016] According to some embodiments of this utility model, the roller is a ball bearing or a needle roller.

[0017] The refrigeration system according to a second aspect embodiment of the present invention includes a cycloidal gear pump as described in the first aspect embodiment.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a front view of a cycloidal gear pump according to an embodiment of the present invention; Figure 2 for Figure 1 The exploded view of the cycloidal gear pump shown (inner rotor omitted); Figure 3 for Figure 1 The cycloidal gear pump shown is a cross-sectional view along the CC section (inner rotor omitted). Figure 4 for Figure 2 A cross-sectional view of the pump body.

[0020] Reference numerals: 101-Cycloidal gear pump, 102-Pump body, 103-Outer rotor, 104-Inner rotor, 105-Outer gear, 106-Through hole, 107-Fixing ring, 108-Opening, 109-Inner gear, 110-Bearing ring, 111-Roller, 112-Boss, 113-Main body, 114-Limiting part, 115-Mounting groove, 116-Inner end face, 117-High pressure side end face. Detailed Implementation The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0021] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0023] In the description of this utility model, unless otherwise explicitly defined, terms such as setting, installing, and connecting should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0024] Figures 1 to 3 A cycloidal gear pump 101 according to one embodiment of the present invention is shown. For example... Figure 1 and Figure 3As shown, the cycloidal gear pump 101 includes a pump body 102, an outer rotor 103, and an inner rotor 104. The cycloidal gear pump 101 also includes a pump housing (not shown), within which the pump body 102, outer rotor 103, and inner rotor 104 are all mounted. The pump body 102 and the pump housing are fixed to each other (e.g., connected by screws). The pump body 102 is generally annular, and the outer rotor 103 is rotatably mounted inside the pump body 102. The inner rotor 104 is rotatably mounted inside the pump body 102, and is located inside the outer rotor 103. The outer rotor 103 includes a plurality of internal teeth 109, and the inner rotor 104 includes a plurality of external teeth 105, the number of external teeth 105 being less than the number of internal teeth 109. In this embodiment, the number of external teeth 105 is 6, and the number of internal teeth 109 is 7, with one fewer external tooth 105 than internal tooth 109. In other embodiments, the number of external teeth 105 may also be two fewer than the number of internal teeth 109. Furthermore, the number of external teeth 105 and internal teeth 109 is not limited to... Figure 1 The specific tooth count settings are not listed here for each scenario. The outer rotor 103 meshes with the inner rotor 104, and the inner rotor 104 is eccentrically positioned relative to the outer rotor 103. "Eccentric" means that the rotation axis of the inner rotor 104 and the rotation axis of the outer rotor 103 do not coincide. The cycloidal gear pump 101 also includes a motor (not shown in the figure), which is connected to the inner rotor 104. The motor drives the inner rotor 104 to rotate, and the rotation of the inner rotor 104 in turn drives the outer rotor 103 to rotate, thereby drawing fluid from the inlet of the cycloidal gear pump 101 between the inner rotor 104 and the outer rotor 103, and delivering the drawn-in fluid to the outlet of the cycloidal gear pump 101. The inlet and outlet of the cycloidal gear pump 101 are located on the pump casing, not shown in the attached figure.

[0025] like Figure 2 and Figure 3 As shown, the cycloidal gear pump 101 also includes a plurality of rollers 111, which are spaced apart circumferentially along the outer rotor 103. The rollers 111 are mounted between the outer circumferential surface of the outer rotor 103 and the inner circumferential surface of the pump body 102, with both the inner circumferential surface of the pump body 102 and the outer circumferential surface of the rotor in contact with the rollers 111. In this embodiment, the rollers 111 roll when the outer rotor 103 rotates relative to the pump body 102. This results in less resistance to the outer rotor 103 during rotation and less wear on both the outer rotor 103 and the pump body 102.

[0026] In existing technology, the outer circumferential surface of the outer rotor directly contacts the wall of the circular hole at the center of the pump body, forming a sliding friction pair. This sliding friction between the outer rotor and the pump body generates a large frictional torque, resulting in significant frictional losses, reduced mechanical efficiency of the cycloidal gear pump, and wasted power. The high friction between the outer rotor and the pump body makes them prone to wear. After wear occurs, the gap between the outer rotor and the pump body may become uneven, causing the outer rotor to jam or vibrate abnormally during rotation, thus reducing the reliability and service life of the cycloidal gear pump. Furthermore, the sliding friction pair is highly sensitive to contaminants in the fluid flowing through the cycloidal gear pump; tiny particles in the fluid exacerbate wear.

[0027] In this embodiment of the cycloidal gear pump 101, rollers 111 are provided between the outer circumferential surface of the outer rotor 103 and the inner circumferential surface of the pump body 102, so that the outer circumferential surface of the outer rotor 103 does not directly contact the inner circumferential surface of the pump body 102. The friction between the outer rotor 103 and the rollers 111 is rolling friction, and the friction between the pump body 102 and the rollers 111 is rolling friction. Since rolling friction is less than sliding friction, this embodiment helps to reduce the friction experienced by the outer rotor 103 and the pump body 102, thereby reducing the wear of the outer rotor 103 and the pump body 102 and improving the performance, reliability, and lifespan of the cycloidal gear pump 101.

[0028] like Figure 2 As shown, in this embodiment, the cycloidal gear pump 101 further includes a bearing ring 110, which, together with a plurality of rollers 111, constitutes a bearing. The bearing ring 110 is installed inside the pump body 102 and wraps around the outer periphery of the outer rotor 103. The rollers 111 are rotatably mounted on the bearing ring 110. The bearing ring 110 may have a plurality of mounting positions (not shown) for mounting the rollers 111, which are through holes 106. A portion of the rollers 111 protrudes from the inner circumferential surface of the bearing ring 110 and contacts the outer rotor 103, while another portion of the rollers 111 protrudes from the outer circumferential surface of the bearing ring 110 and contacts the pump body 102. The bearing ring 110 may be fixed to the pump body 102, for example, by snap-fitting, bonding, or screwing. Alternatively, as described below, the retaining ring 107 presses the bearing ring 110 onto the boss portion 112, and the retaining ring 107 and the boss portion 112 clamp the bearing ring 110, thereby fixing the bearing ring 110 and the pump body 102 to each other.

[0029] In some embodiments not shown, the cycloidal gear pump 101 may omit the bearing ring 110 and instead directly provide a mounting groove 115 for mounting the rollers 111 on the outer circumferential surface of the outer rotor 103, with a portion of the rollers 111 protruding from the mounting groove 115 and contacting the inner circumferential surface of the pump body 102. Alternatively, the mounting groove 115 for mounting the rollers 111 may be directly provided on the inner circumferential surface of the pump body 102, with a portion of the rollers 111 protruding from the mounting groove 115 and contacting the outer circumferential surface of the outer rotor 103.

[0030] In this embodiment, roller 111 is a needle roller, that is, roller 111 is cylindrical or needle-shaped. This is suitable for cases where the axial dimensions of the outer rotor 103 and the pump body 102 are large. In some other embodiments not shown, if the axial dimensions of the outer rotor 103 and the pump body 102 are small, roller 111 can also be set as a ball, that is, roller 111 is spherical.

[0031] The number of rollers 111 is N, and in some embodiments, 40 ≤ N ≤ 60. This arrangement allows the outer rotor 103 to rotate smoothly relative to the pump body 102. Furthermore, the multiple rollers 111 can be arranged at uniform intervals along the circumference of the outer rotor 103.

[0032] like Figure 4 As shown, the pump body 102 defines an annular mounting groove 115, within which the bearing ring 110 is located. The mounting groove 115 is used to accommodate the bearing ring 110 for positioning during assembly of the cycloidal gear pump 101. Specifically, the pump body 102 includes a main body portion 113, a boss portion 112, and a limiting portion 114, all of which are annular. Axially, the boss portion 112 is located at one end of the main body portion 113, and the limiting portion 114 is located at the other end. Both the boss portion 112 and the main body portion 113 protrude inward relative to the main body portion 113 (protruding radially inward along the main body portion 113). The main body portion 113, the boss portion 112, and the limiting portion 114 together define the mounting groove 115. The inner circumferential surface of the main body 113, the inner end face 116 of the boss 112, and the inner end face 116 of the limiting part 114 all serve as part of the wall of the mounting groove 115. The inner circumferential surface of the main body 113 can serve as the inner circumferential surface of the pump body 102, and the roller 111 contacts the inner circumferential surface of the main body 113.

[0033] like Figure 2 and Figure 3 As shown, the cycloidal gear pump 101 also includes a retaining ring 107, which is engaged within the mounting groove 115. (Please refer to...) Figure 3 and Figure 4The inner end face 116 of the boss portion 112 abuts against one end face (lower end face of the bearing ring 110), and the retaining ring 107 abuts against the other end face (upper end face of the bearing ring 110), thereby preventing the bearing ring 110 from disengaging from the mounting groove 115.

[0034] The following is combined Figure 3 and Figure 4 This describes the process of installing the bearing ring 110, which already has rollers 111 installed, into the pump body 102. First, the bearing ring 110 is placed into the mounting groove 115 of the pump body 102 from top to bottom, so that the boss portion 112 supports the bearing ring 110. The bearing ring 110 has a certain degree of elasticity and can deform slightly to pass through the limiting portion 114. Then, the retaining ring 107 is inserted into the mounting groove 115. The limiting portion 114 blocks the upper surface of the retaining ring 107 to prevent the retaining ring 107 from coming out. The lower surface of the retaining ring 107 abuts against the upper end face of the bearing ring 110, and the retaining ring 107 and the boss portion 112 clamp the bearing ring 110.

[0035] like Figure 2 As shown, in this embodiment, the retaining ring 107 is elastic and can be made of an elastic metallic or non-metallic material. The retaining ring 107 is annular with an opening 108, allowing it to deform in its radial and circumferential directions, thus facilitating its insertion into the mounting groove 115.

[0036] like Figure 4 As shown, in some embodiments, the maximum wall thickness of the pump body 102 in the radial direction is A, and the depth of the mounting groove 115 is B, where A / 4 ≤ B ≤ A / 3. This arrangement ensures that the depth of the mounting groove 115 is moderate, allowing it to adequately accommodate the bearing ring 110, and that the groove depth is not excessive, thus preventing insufficient strength of the pump body 102.

[0037] Please combine Figure 1 and Figure 4 In some embodiments, the high-pressure side end face 117 of the pump body 102 is provided with a plurality of through holes 106, which communicate with the mounting groove 115, and the plurality of through holes 106 are distributed at intervals along the circumference of the pump body 102. The cycloidal gear pump 101 passing through the pump body 102 flows from the low-pressure side of the pump body 102 to the high-pressure side of the pump body 102 (the fluid pressure increases after being compressed by the outer rotor 103 and the inner rotor 104). Figure 4For example, the lower side of the pump body 102 is the high-pressure side of the pump body 102, and the upper side of the pump body 102 is the low-pressure side of the pump body 102. A portion of the fluid flowing out from the high-pressure side end face 117 can flow into the mounting groove 115 through the through hole 106 and towards the vicinity of the roller 111. The fluid passing through smaller areas (such as the through hole 106, the gap between the roller 111 and the bearing ring 110) will cause a certain pressure loss. Correspondingly, the pressure of the outer rotor 103 on the roller 111 is reduced, which reduces friction between the two, thus reducing frictional loss.

[0038] The cycloidal gear pump of any of the above embodiments can be used in a refrigeration system to deliver refrigerant to the refrigeration system.

[0039] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A cycloidal gear pump, characterized in that, include: Pump body; An outer rotor is rotatably mounted inside the pump body, and the outer rotor includes a plurality of internal teeth; An inner rotor is rotatably mounted inside the pump body and is located inside the outer rotor. The inner rotor is eccentrically positioned relative to the outer rotor. The inner rotor includes a plurality of external teeth, the number of which is less than the number of internal teeth. The outer rotor meshes with the inner rotor. Multiple rollers are mounted between the outer circumferential surface of the outer rotor and the inner circumferential surface of the pump body. Both the outer circumferential surface and the inner circumferential surface of the pump body are in contact with the rollers. The multiple rollers are distributed at intervals along the circumferential direction of the outer rotor. When the outer rotor rotates relative to the pump body, the rollers roll.

2. The cycloidal gear pump according to claim 1, characterized in that, The cycloidal gear pump also includes a bearing ring, which is installed in the pump body and surrounds the outer periphery of the outer rotor, and the roller is rotatably installed on the bearing ring.

3. The cycloidal gear pump according to claim 2, characterized in that, The pump body defines an annular mounting groove, and the bearing ring is located within the mounting groove.

4. The cycloidal gear pump according to claim 3, characterized in that, In the radial direction of the pump body, the maximum wall thickness of the pump body is A, the depth of the mounting groove is B, and A / 4≤B≤A / 3.

5. The cycloidal gear pump according to claim 3, characterized in that, The high-pressure side end face of the pump body is provided with multiple through holes, which are connected to the mounting groove, and the multiple through holes are distributed at intervals along the circumference of the pump body.

6. The cycloidal gear pump according to claim 3, characterized in that, The pump body includes a main body and a boss portion, both of which are annular. The boss portion is connected to the main body and protrudes inward relative to the main body. In the axial direction of the pump body, the boss portion is located at one end of the main body. The inner circumferential surface of the main body and the inner end face of the boss portion are both part of the wall surface of the mounting groove. The cycloidal gear pump also includes a retaining ring, which is engaged in the mounting groove. The inner end face of the retaining ring abuts against one end face of the bearing ring, and the retaining ring abuts against the other end face of the bearing ring to prevent the bearing ring from disengaging from the mounting groove.

7. The cycloidal gear pump according to claim 6, characterized in that, The fixing ring is elastic and has an open ring shape.

8. The cycloidal gear pump according to claim 1, characterized in that, The number of rollers is N, where 40 ≤ N ≤ 60.

9. The cycloidal gear pump according to claim 1, characterized in that, The roller is either a ball bearing or a needle roller.

10. A refrigeration system, characterized in that, Including the cycloidal gear pump as described in any one of claims 1 to 9.

Images