Anti-rotation structure of vortex air compressor, oil-free vortex air compressor and oxygen generator

Abstract

An anti-rotation structure of a vortex air compressor is characterized in that an oil-free vortex air compressor is provided with a static vortex plate and a dynamic vortex plate, and the two vortex plates are connected through a plurality of anti-rotation structures; the anti-rotation structure comprises a crank throw, the two ends of the crank throw are each provided with at least one bearing, and the bearings at the two ends are installed in bearing holes in the two scroll plates respectively; wherein one orifice of the bearing hole positioned on the opposite surfaces of the two scroll plates is used as a press-in opening of the bearing, and the other orifice of the bearing hole positioned on the opposite surfaces of the two scroll plates is provided with a step surface to form limitation of the bearing in the press-in direction; the two ends of the crank throw are further provided with locking structures, the two locking structures apply axial pre-tightening force in the same direction as the press-in direction to the opposite faces of the bearings at the two ends respectively, and the opposite faces of the two scroll plates are attached and locked. The step faces are arranged at the bearing holes in the front faces of the two scroll plates, and the bearings are pressed into the bearing holes from the back faces and then locked on the back faces, so that the bearings are supported in a balanced and stable mode and are not prone to disengaging from the bearing holes.

Description

Technical Field

[0001] The utility model relates to the technical field of oxygen concentrators, in particular to the technical field of vortex air compressors used in small and micro oxygen concentrators, and specifically to a vortex air compressor anti-self-rotation structure, an oil-free vortex air compressor and an oxygen concentrator. Background Art

[0002] The traditional scroll air compressor is composed of a movable scroll, a fixed scroll, a bracket, an anti-rotation mechanism and a driving part. The anti-rotation mechanism includes a crank and a bearing, usually in three groups; the driving part includes a motor and an eccentric main shaft, wherein the eccentric part of the eccentric main shaft is connected to the movable scroll through a bearing, and the other end is connected to the motor. The eccentric main shaft is driven by the motor to rotate and drive the movable scroll, and under the restriction of the crank, it is prevented from rotating, so that the movable scroll moves relative to the fixed fixed fixed scroll in a predetermined trajectory, and the movable scroll cooperates with the fixed scroll to achieve air compression. Since this type of scroll air compressor has the advantages of fewer parts, stable operation, low noise, and long life, it is increasingly used in oil-free environment air compression systems.

[0003] At present, oil-free scroll air compressors are often used in centralized oxygen supply systems or medium-to-large oxygen supply equipment such as micro-pressure oxygen supply warehouses, which have low requirements for the size of the compressor. When oil-free scroll air compressors are used in small and micro oxygen generators, they have higher requirements for the size of the structure; therefore, the oil-free scroll air compressors used in centralized oxygen supply systems or micro-pressure oxygen supply warehouses can be scaled down and then used in small and micro oxygen generators.

[0004] like Figure 6 The figure shows the structure of the movable scroll of a commonly used oil-free scroll air compressor, where the side with the scroll teeth is defined as the front side and the other side is defined as the back side; the bearing of the anti-self-rotation mechanism is pressed into the bearing hole from the front side through interference, but since the scroll is usually made of aluminum alloy as the raw material and the bearing is usually made of steel as the raw material, the thermal expansion coefficients of the two are different, and the bearing is subjected to the axial preload from the nut, which is opposite to the force of the pressed bearing. Therefore, the heat generated during the operation of the scroll will cause it to deform differently from the bearing, which will affect the interference and cause the bearing to loosen. To solve this problem, the current solution is to add a pair of bolt holes next to each bearing hole and limit the bearing through the bolt head. This solution has the following shortcomings:

[0005] 1. Due to the space limitation of small and micro oxygen concentrators, the bolt specifications are generally small, the contact area between the bolt head and the bearing is limited, the limiting force provided is small, and there is also a risk of the bearing coming out of the bearing hole;

[0006] 2. Due to the influence of spatial layout, the bolts cannot be distributed symmetrically (this situation is different from the present invention Figure 2-3The screw arrangement is the same as in the example above), which will cause unbalanced force and generate torque, thus affecting the service life;

[0007] 3. Since the bearing is installed from the front of the scroll and there is a tolerance on the bearing height, when the two scrolls are assembled, the bearing will increase the axial cumulative tolerance, which increases the difficulty of assembly and matching (see Figure 8 ).

[0008] Therefore, how to solve the above-mentioned deficiencies in the prior art has become a topic to be studied and solved in the present invention. Utility Model Content

[0009] The utility model aims to provide a scroll air compressor anti-self-rotation structure, an oil-free scroll air compressor and an oxygen generator.

[0010] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0011] In a first aspect of the utility model, a scroll air compressor anti-self-rotation structure is provided, wherein the scroll air compressor comprises a fixed scroll and a movable scroll, and the two scrolls are connected by a plurality of the anti-self-rotation structures;

[0012] The anti-rotation structure comprises a crank, at least one bearing is disposed at each end of the crank, and the bearings at both ends of the crank are respectively installed in the bearing holes on the fixed scroll and the orbiting scroll;

[0013] Wherein, one opening of the bearing hole located on the opposite back surfaces of the two scrolls serves as the pressing inlet of the bearing, and the other opening of the bearing hole located on the opposite surfaces of the two scrolls has a step surface, constituting a restriction on the pressing direction of the bearing;

[0014] A locking structure is also provided at both ends of the crank, and the two locking structures respectively apply an axial preload force which is the same as the pressing direction to the opposite back sides of the bearings at both ends, thereby forming a fitting and locking relationship between the opposite sides of the two scroll plates.

[0015] Preferably, the bearing adopts a deep groove ball bearing, which has an interference fit with the bearing hole; there are many small-sized deep groove ball bearings on the market, which are easy to choose and low in cost, and are therefore more suitable for use in the utility model; the number of deep groove ball bearings in each bearing hole can be selected based on the required load-bearing capacity and the material of the bearing.

[0016] Further preferably, at least two of the deep groove ball bearings are installed in the bearing hole, and a gasket is arranged between two adjacent deep groove ball bearings, and the thickness of the gasket is equal to or slightly larger than the axial clearance of the two deep groove ball bearings; arranging two deep groove ball bearings in one bearing hole is the optimal solution, and by utilizing the setting of the gasket, the position of the inner ring and the outer ring can be fixed after the bearing is locked, without axial movement, thereby avoiding affecting the distance between the moving and static scroll plates, thereby reducing the difficulty of assembling and matching the two scroll plates.

[0017] More preferably, the gasket contacts with the inner ring or the outer ring of the deep groove ball bearing correspondingly, and when the gasket contacts with the inner ring, it is difficult to position and install the gasket.

[0018] Preferably, the step surface is arranged in an annular shape, and the annular step surface can provide the bearing with uniform supporting force, and cooperate with the locking structure to achieve a certain self-locking effect.

[0019] Preferably, the locking structure comprises a nut, which cooperates with the screw groove at the end of the crank, and the nut abuts against the bearing at the outer end of the crank to apply the axial preload force to the bearing.

[0020] Preferably, the bearing may also adopt other bearings of smaller size, such as small angular contact bearings, which are less available on the market or need to be customized and are costly. When small angular contact bearings are adopted, angular contact bearings need to be arranged in pairs in each bearing hole, and the paired angular contact bearings have no axial clearance to avoid axial cumulative tolerance caused by the axial clearance when assembling the two scroll plates, thereby increasing the difficulty of assembly and matching.

[0021] Preferably, the anti-rotation structure also includes a bearing outer end limiting structure arranged at the one orifice for limiting the bearing from escaping from the bearing hole from the pressing inlet. The limiting structure applies another axial preload force to the bearing, and the direction of the axial preload force is the same as the pressing direction, so as to prevent the bearing from escaping from the pressing inlet.

[0022] Further preferably, the bearing outer end limiting structure includes a screw, the screw cap abuts against the outer ring of the bearing, and the screw body is fixedly connected to the corresponding scroll plate. The screw is easy to assemble and the assembly cycle can be shortened.

[0023] Further preferably, the bearing outer end limiting structure includes a retaining spring, and the retaining spring is installed in the one hole. The retaining spring limiting is also relatively simple and the assembly difficulty is also relatively low.

[0024] A second aspect of the utility model provides an oil-free scroll air compressor, which includes the scroll air compressor anti-self-rotation structure.

[0025] A third aspect of the utility model provides an oxygen concentrator, which includes the above-mentioned oil-free scroll air compressor.

[0026] The working principle and advantages of this utility model are as follows:

[0027] The utility model provides a step surface at the front bearing holes of the two scroll plates, and the bearings are pressed into the bearing holes from the back sides of the two scroll plates and then locked at the back sides, so that the axial preload force applied to the bearing is the same as the pressing direction of the bearing, and the bearing is supported by the step surface in the force direction, the contact area with the bearing is large, the bearing support is balanced and stable, and it is not easy to fall out of the bearing hole. The entire anti-rotation structure has strong stability and a long service life.

[0028] The front sides of the two scroll plates of the utility model are provided with an annular step surface. After the two scroll plates are fitted and locked, the axial distance between the two scroll plates is determined by the platform height of the crank and the distance between the bearing end faces on the front sides of the two scroll plates. The height tolerance of the bearing will not cause the axial clearance tolerance between the scroll teeth between the two scroll plates. Therefore, the structural design can eliminate the cumulative tolerance brought by the bearings, reduce the difficulty of matching, and increase the performance consistency of the finished product.

[0029] In the utility model, the large diameter of the bearing hole is arranged on the back of the two scroll disks. When the scroll line is processed on the front of the scroll disk, the special tooling for the scroll line can be directly positioned through the bearing hole. The tooling fits with the large diameter inner wall of the bearing hole to increase the relative positioning accuracy of the scroll line and the bearing hole.

[0030] The utility model uses deep groove ball bearings in pairs in each bearing hole, and a gasket is arranged between the two deep groove ball bearings, the gasket can only contact with the outer ring of the bearing or the inner ring of the bearing, and the thickness of the gasket is equal to or slightly greater than the axial clearance of the two deep groove ball bearings. In this way, after locking, the positions of the inner ring of the bearing and the outer ring of the bearing are fixed without axial movement, and the distance between the dynamic and static scroll plates cannot be affected, thereby ensuring the overall stability of the air compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Attached Figure 1 This is an exploded view of the utility model;

[0032] Attached Figure 2 It is a three-dimensional diagram of the utility model;

[0033] Attached Figure 3 This is a back structural diagram of the static scroll disk of the utility model;

[0034] Attached Figure 4 This is a back structural diagram of the movable scroll of the utility model;

[0035] Attached Figure 5 This is a cross-sectional view of the anti-rotation structure of the utility model;

[0036] Attached Figure 6 This is the cross-section diagram of the anti-rotation structure before optimization;

[0037] Attached Figure 7This is the dimension diagram of the anti-rotation structure of the utility model;

[0038] Attached Figure 8 This is the dimension diagram of the anti-rotation structure before optimization;

[0039] Attached Fig. 9 This is a cross-sectional view of the utility model gasket located on the outer ring of the bearing;

[0040] Attached Fig.10 This is a cross-sectional view of the gasket of the utility model located on the inner ring of the bearing.

[0041] In the above figures: 1 static scroll; 2 orbiting scroll; 3 crank; 4 bearing; 5 bearing hole; 51 pressure inlet; 6 step surface; 7 locking structure; 8 gasket; 9 bearing outer end limit structure. DETAILED DESCRIPTION

[0042] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0043] Embodiment: The present invention will be clearly described below with diagrams and detailed descriptions. After understanding the embodiments of the present invention, any person skilled in the art can make changes and modifications based on the techniques taught by the present invention without departing from the spirit and scope of the present invention.

[0044] The terms used herein are only for describing specific embodiments and are not intended to be limiting of the present invention. Singular forms such as "a", "this", "here", "this" and "the" as used herein also include plural forms.

[0045] As used herein, “connected” or “positioned” may refer to two or more components or devices being in direct physical contact with each other, or being in indirect physical contact with each other, or may refer to two or more components or devices operating or moving with each other.

[0046] The terms “include,” “including,” “have,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0047] The terms used in this document generally have the ordinary meaning of each term used in this field, in the context of the case and in the specific context, unless otherwise noted. Certain terms used to describe the present invention will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the present invention.

[0048] See attached Figure 1-8 A scroll air compressor anti-rotation structure, the scroll air compressor comprises a fixed scroll 1 and a movable scroll 2, the two scrolls are connected by a plurality of the anti-rotation structures.

[0049] The anti-rotation structure includes a crank 3, at each end of which is provided with at least one bearing 4, preferably two, and the bearing 4 is preferably a deep groove ball bearing, and a gasket 8 is provided between the two deep groove ball bearings, and the gasket 8 is in contact with the inner ring or outer ring of the deep groove ball bearing, such as Fig. 9 The diagram shown is a schematic diagram of the gasket 8 corresponding to the outer ring of the bearing, as shown in Fig.10 Shown is a schematic diagram of the gasket 8 corresponding to the inner ring of the bearing.

[0050] The sides of the two scrolls with spiral teeth are defined as the front side, and the sides without spiral teeth are defined as the back side. Then, the opposite sides of the two scrolls are the two front sides, and the opposite sides are the two back sides. An opening of the bearing hole 5 located on the opposite back sides of the two scrolls is used as a pressure inlet 51 of the bearing 4. The bearings 4 at both ends of the crank 3 are respectively pressed into the bearing holes 5 on the two scrolls through the pressure inlet 51 to achieve interference fit between the bearing 4 and the bearing hole 5.

[0051] The other opening of the bearing hole 5 located on the opposite sides of the two scrolls is provided with a step surface 6, which limits the pressing direction of the bearing 4; the step surface 6 is preferably an annular step surface 6;

[0052] A locking structure 7 is also provided at both ends of the crank 3, and the locking structure 7 includes a nut, which cooperates with the screw groove at the end of the crank 3, and the nut abuts against the bearing 4 at the outer end of the crank 3; the two nuts respectively apply an axial preload force which is the same as the pressing direction to the opposite back sides of the bearings 4 at both ends, thereby forming a fitting and locking relationship between the opposite surfaces of the two scroll plates; the axial preload force is opposite to the direction in which the bearing 4 escapes from the bearing hole 5.

[0053] The anti-rotation structure also includes a bearing outer end limiting structure 9 disposed at the one orifice for limiting the bearing 4 from escaping from the bearing hole 5 from the pressure inlet 51; the bearing outer end limiting structure 9 may include a screw, the screw head of the screw abuts against the outer ring of the bearing 4, and the screw body is fixedly connected to the corresponding scroll plate (see Figure 2-4 ); The bearing outer end limiting structure 9 may also include a retaining spring, which is installed in the one hole (not shown in the figure).

[0054] This structural design allows the bearing 4 to be pressed into the bearing hole 5 from the back of the scroll disk when installed. After the locking structure 7 is assembled and locked, the axial preload force borne by the bearing 4 is the same as the pressing direction, and is supported by the annular step surface 6 in the axial force direction, so the support is balanced and stable.

[0055] In addition, since the large diameter of the bearing hole 5 is set on the back of the scroll disk, when the scroll line is processed on the front of the scroll disk, the special tooling for the scroll line can be directly positioned through the bearing hole 5. The tooling fits with the large diameter inner wall of the bearing hole 5, thereby increasing the relative positioning accuracy of the scroll line and the bearing hole 5.

[0056] Since the front of the two scrolls is provided with an annular step surface 6, after the two scrolls are fitted and locked, the axial distance between the two scrolls is determined by the platform height of the crank 3 and the distance between the end faces of the bearings 4 on the front of the two scrolls. The height tolerance of the bearings 4 will not cause the axial clearance tolerance between the scroll teeth between the two scrolls. Therefore, this structural design can eliminate the cumulative tolerance caused by the bearings 4 and reduce the difficulty of matching. For details, see Figure 5-8 ;

[0057] in, Figure 6 and Figure 8 For the anti-rotation structure before optimization, Figure 5 and Figure 7 The anti-rotation structure is optimized for the utility model; Figure 7 In the figure, the axial distance between the front of the orbiting scroll 2 and the front of the fixed scroll 1 is L12, the distance between the end faces of the crank 3 is L3, and the gap between the vortex top and the vortex bottom of the orbiting scroll 2 and the fixed scroll 1 is controlled by the difference between L12 and L3; Figure 8 In the figure, the value of L12 is determined by the sum of the distance L1 between the top surface of the vortex tooth of the fixed scroll 1 and the bottom surface of the bearing hole 5 and the distance L2 between the front surface of the movable scroll 2 and the bottom surface of the bearing hole 5. Both L1 and L2 can be controlled by machining. The distance L12 between the end surfaces of the bearing 4 of the two scrolls is obtained by subtracting the height of the bearing 4 from the sum of the above L1 and L2. The tolerance of L12 increases the height tolerance of the bearing 4. The clearance tolerance between the vortex tooth top and the vortex tooth bottom of the movable scroll 2 and the fixed scroll 1 becomes larger, which increases the difficulty of assembly and matching and reduces the performance consistency of the finished product.

[0058] Due to the demand for miniaturized applications, the size of oil-free scroll air compressors is also developing in the direction of miniaturization. The commonly used models of paired angular contact bearings 4 are larger and cannot meet the miniaturization conditions. Therefore, the bearings 4 of the anti-reversal structure of this embodiment can only use commonly used models with smaller specifications of deep groove ball bearings. After using deep groove ball bearings, due to the axial clearance of bearings 4, the distance between the two will change accordingly, which is unstable as a whole and affects the capacity of the compressor. Therefore, we set a gasket 8 between the deep groove ball bearings used in pairs. The thickness of the gasket 8 is equal to or slightly larger than the axial clearance of the two deep groove ball bearings. In this way, after locking, the inner ring of the bearing 4 and the outer ring of the bearing 4 are fixed in position, without axial movement, and cannot affect the distance between the moving and static disks.

[0059] See also Figure 1-2 The utility model also provides an oil-free scroll air compressor, including the scroll air compressor anti-self-rotation structure as described above.

[0060] The utility model also provides an oxygen generator, comprising the oil-free vortex air compressor as described above; the oxygen generator can be a small or micro oxygen generator.

[0061] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A scroll air compressor anti-rotation structure, the scroll air compressor comprising a fixed scroll (1) and a movable scroll (2), the two scrolls being connected via a plurality of the anti-rotation structures, characterized in that: The anti-rotation structure comprises a crank (3), at least one bearing (4) being provided at each end of the crank (3), and the bearings (4) at both ends of the crank (3) are respectively mounted in bearing holes (5) on the fixed scroll (1) and the orbiting scroll (2); Wherein, one opening of the bearing hole (5) located on the opposite sides of the two scrolls serves as a pressing inlet of the bearing (4), and the other opening of the bearing hole (5) located on the opposite sides of the two scrolls has a step surface (6) constituting a restriction on the pressing direction of the bearing (4); A locking structure (7) is also provided at both ends of the crank (3), and the two locking structures (7) respectively apply an axial preload force in the same direction as the pressing direction to the opposite back surfaces of the bearings (4) at the two ends, thereby forming a fitting and locking relationship between the opposite surfaces of the two scroll plates.

2. The scroll air compressor anti-self-rotation structure according to claim 1, characterized in that: The bearing (4) is a deep groove ball bearing which is interference fit with the bearing hole (5).

3. The scroll air compressor anti-rotation structure according to claim 2, characterized in that: At least two of the deep groove ball bearings are installed in the bearing hole (5), and a gasket (8) is arranged between two adjacent deep groove ball bearings, and the gasket (8) is in corresponding contact with the inner ring or the outer ring of the deep groove ball bearing.

4. The scroll air compressor anti-self-rotation structure according to claim 1, characterized in that: The step surface (6) is arranged in a ring shape.

5. The scroll air compressor anti-rotation structure according to claim 1, characterized in that: The locking structure (7) comprises a nut, the nut cooperates with a screw groove at the end of the crank (3), and the nut abuts against the bearing (4) at the outer end of the crank (3).

6. The scroll air compressor anti-self-rotation structure according to claim 1, characterized in that: The anti-rotation structure also includes a bearing outer end limiting structure (9) disposed at the one hole opening and used to limit the bearing (4) from escaping from the bearing hole (5) through the pressure inlet.

7. The scroll air compressor anti-self-rotation structure according to claim 6, characterized in that: The bearing outer end limiting structure (9) comprises a screw, the screw cap of which abuts against the outer ring of the bearing (4), and the screw body is fixedly connected to the corresponding scroll plate.

8. The scroll air compressor anti-self-rotation structure according to claim 6, characterized in that: The bearing outer end limiting structure (9) comprises a retaining spring, and the retaining spring is installed in the one hole.

9. An oil-free scroll air compressor, characterized in that: It comprises the scroll air compressor anti-self-rotation structure as described in any one of claims 1-8.

10. An oxygen concentrator, characterized in that: It comprises the oil-free scroll air compressor as claimed in claim 9.

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