Low-micro vibration piston body and application of low-micro vibration piston body in linear compressor

Abstract

The invention provides a low-micro vibration piston body and application thereof in a linear compressor, and the low-micro vibration piston body is a cylinder with a tapered end part. The compressor solves the problems of how to reduce radial micro-vibration of the piston in the compressor and how to reduce collision and friction between the piston and an air cylinder in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of low-micro-vibration piston bodies of linear compressors, and in particular to a low-micro-vibration piston body and application thereof in linear compressors. Background Art

[0002] Linear compressors generate pressure waves through the high-frequency reciprocating motion of the piston in the cylinder. The reciprocating motion of the piston will generate vibration, which is usually reduced by the method of two pistons moving opposite to each other or designing opposite vibration reduction. Even so, due to the uneven pressure on the piston cylindrical surface during the high-frequency reciprocating motion of the piston, the piston will vibrate radially, making the micro-vibration of the compressor larger, and even the piston will collide and rub against the cylinder wall, causing wear on the piston and cylinder surface.

[0003] Specifically, during the reciprocating motion of the compressor piston in the cylinder, it is affected by unbalanced lateral forces such as gravity and gas force, causing the piston to deflect to one side in the cylinder. Figure 1 As shown), when the piston compresses the gas, the average gas pressure p1 of the gap on the side of the piston away from the cylinder wall is greater than the average gas pressure p2 of the gap on the side of the piston close to the cylinder wall (as shown in Figure 2 As shown in the figure, the piston deviates further away from the cylinder axis and the lateral pressure on the piston increases.

[0004] As the requirements for micro-vibration in aviation, aerospace, and precision instruments become increasingly higher, it is necessary to reduce the micro-vibration generated by the operation of the compressor. Therefore, how to reduce the radial micro-vibration of the piston in the compressor and reduce the collision and friction between the piston and the cylinder has become a technical problem that needs to be solved. Summary of the invention

[0005] The object of the present invention is to provide a low-micro-vibration piston body and its application in a linear compressor

[0006] , mainly to solve the problem of how to reduce the radial micro-vibration of the piston in the compressor and reduce the collision and friction between the piston and the cylinder in the above-mentioned prior art.

[0007] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a low-micro vibration piston body, characterized in that the piston body is a cylinder with a tapered end.

[0008] Furthermore, the length of the piston body includes a tapered region length L1 and a non-tapered region length L2, where L1:L2=1±0.5.

[0009] Furthermore, the diameter D1 of the tapered end of the piston body is smaller than the diameter D2 of the non-tapered region of the piston body, and the difference between the diameters is in the range of 10 to 60 μm.

[0010] An application of a low-micro-vibration piston body as described above in a linear compressor is characterized in that: the inner diameter of the cylinder of the linear compressor is D, the piston body is located in the cylinder, and the diameter difference between the non-tapered area diameter D2 of the piston body and the inner diameter D of the cylinder is in the range of 10μm to 40μm.

[0011] In view of the above technical features, the present invention has the following beneficial effects:

[0012] 1. A low-micro-vibration piston body of the present invention is a cylinder with a tapered end, which helps to reduce the resultant force of the piston body deviating from the center position and reduce the vibration displacement of the piston body, that is, reduce the radial micro-vibration of the piston body in the compressor, reduce the operating micro-vibration of the linear compressor, and reduce the collision and friction between the piston and the cylinder.

[0013] 2. The application of a low-micro-vibration piston body of the present invention in a linear compressor reduces the uneven force on the piston surface caused by the displacement of the piston body, reduces the probability of contact with the cylinder wall and the positive contact pressure, reduces the wear of the piston body and the inner wall of the cylinder, reduces the micro-vibration of the compressor, and ensures the long life of the linear compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The invention relates to an application of a compression piston body in the prior art, which is a cylinder without a taper at the end and the piston body in a cylinder.

[0015] Figure 2 It is a curve diagram of the pressure of the gap between the piston body and the cylinder when the cylindrical piston body compresses gas in the prior art.

[0016] Figure 3 In the specific embodiment 1, the piston body is a cylinder with a tapered end and the application 1 of the piston body in the cylinder.

[0017] Figure 4 In the specific embodiment 1, the piston body is a cylinder with a tapered end and the application 2 of the piston body in the cylinder.

[0018] Figure 5 It is a curve diagram of the pressure in the gap between the piston body and the cylinder when the piston body with a taper at the end compresses gas in specific embodiment 1.

[0019] Figure 6 It is the lateral resultant force when the bevel length (ie, the tapered area length L1) and the non-bevel length (ie, the non-tapered area length L2) of the piston body in the specific embodiment 1 are in different proportions.

[0020] Figure 7 1 is a graph showing the relationship between the gas leakage rate caused by the gap and the gap between the piston and the cylinder in the specific embodiment 1. In the figure: 1, piston body; 2, cylinder;

[0021] V: piston movement speed;

[0022] Pc: Average gas pressure in the compression chamber (piston front end);

[0023] Pa: Average gas pressure in the back pressure chamber (rear end of the piston);

[0024] p1: average gas pressure at the gap between the piston and the cylinder wall;

[0025] p2: The average gas pressure in the gap between the piston and the cylinder wall. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0027] See also Figures 3 to 7 , Specific embodiment 1, this embodiment 1 provides a low-micro vibration piston body, the piston body 1 is a cylinder with a tapered end (such as Figure 3 As shown), when the piston body 1 compresses the gas, the average gas pressure p1 of the gap between the piston body 1 and the cylinder 2 wall is less than the average gas pressure p2 of the gap between the piston body 1 and the cylinder 2 wall (as shown). Figure 4 and Figure 5 As shown in the figure, the piston body 1 will be subjected to a force that returns to the axis of the cylinder 2 so that the piston body 1 is centered in the cylinder 2. The piston body 1 with a taper at the end helps to reduce the resultant force of the piston body 1 deviating from the center position, reduce the vibration displacement of the piston body 1, that is, reduce the radial micro-vibration of the piston body 1 in the compressor, reduce the operating micro-vibration of the linear compressor, and reduce the collision and friction between the piston and the cylinder 2.

[0028] Preferably, the length of the piston body 1 includes the length L1 of the tapered area and the length L2 of the non-tapered area, and L1:L2=1±0.5. For example, under the premise of effectively controlling the amount of air leakage, the bevel angle is increased (i.e., a taper design is added to the end of the piston body 1) so that the resultant force on the piston body 1 is as small as possible during the full motion cycle. Taking a compressor with a diameter of 20 mm as an example, the resultant force under different bevel ratios (such as Figure 6As shown), it can be seen that when the bevel length L1 (L1 is the length of the tapered area of ​​the piston body 1) is about half the length of the entire piston body 1 (i.e. L1+L2) (i.e. L1:L2=1), the resultant force on the piston body 1 is the smallest. When the ratio of L1:L2 is far away from 1, the resultant force on the piston body 1 increases. At the same time, considering the impact of leakage caused by excessive clearance, the amount of leakage is inversely proportional to the length of the non-beveled piston. When the bevel length of the piston body 1 is large, the amount of leakage will increase significantly, resulting in a significant deterioration in performance. Therefore, it is recommended that L1:L2=1±0.5. Within this size range, it can not only reduce the resultant force on the piston, but also ensure the performance of the compressor.

[0029] Preferably, the diameter D1 of the tapered end of the piston body 1 is smaller than the diameter D2 of the non-tapered region of the piston body 1 , and the difference between the diameters is in the range of 10 to 60 μm.

[0030] The diameter D1 of the taper end of the piston body 1 is smaller than the diameter D2 of the non-tapered area of ​​the piston body 1, and the diameter difference range is 10 to 60 μm. This is to take into account that when the piston body 1 hits the wall of the cylinder 2 during the tilting process, the piston point A or B hits the cylinder 2, so that the piston end a and the cylinder 2 can form a wedge angle. Because the diameter difference between the diameter D2 of the non-tapered area of ​​the piston body 1 and the inner diameter D of the cylinder 2 is designed to be between 10 μm and 40 μm, and the distance between the piston shaft support point O and the piston end b is generally greater than 1 / 4 of the piston length. When the diameter difference between the non-tapered area diameter D2 of the piston body 1 and the inner diameter D of the cylinder 2 is 40 μm, the piston L1:L2=1.5, and the distance between the piston shaft support point O and the piston end b is 1 / 4 of the piston length, when the piston point A hits the cylinder 2 wall, the piston tilts 20 μm, and the piston end a tilts 38.5 μm toward the cylinder 2 wall. Considering that after the piston is tilted, the end a of the piston near the wall of cylinder 2 can still form a wedge angle with cylinder 2, the diameter difference between the end a of the piston and cylinder 2 should be greater than (38.5+10)*2=97μm, rounded to 100μm. Therefore, it is recommended that the maximum diameter difference between the diameter D1 of the taper end of the piston body 1 and the diameter D2 of the non-tapered area is 60μm (i.e. 100μm-40μm=60μm). When the diameter difference between the diameter D2 of the non-tapered area of ​​the piston body 1 and the inner diameter D of the cylinder 2 is 10μm, the piston L1:L2=1.5, the piston shaft support point O is far away, assuming that the distance from the end b of the piston is 4 times the length of the piston, when the piston point A hits the wall of cylinder 2, the piston tilts 5μm, and the end a of the piston tilts 5.7μm toward the wall of cylinder 2. Considering that after the piston body 1 is tilted, the end a of the piston close to the wall of the cylinder 2 can still form a wedge angle with the cylinder 2, the diameter difference between the end a of the piston and the cylinder 2 should be greater than (5.7+5)*2=21.4μm, rounded to 20μm. Therefore, it is recommended that the minimum diameter difference between the diameter D1 of the tapered end of the piston body 1 and the diameter D2 of the non-tapered area is 10μm (that is, 20μm-10μm=10μm). Therefore, it is recommended that the range of the diameter difference between the diameter D1 of the tapered end of the piston body 1 and the diameter D2 of the non-tapered area is 10 to 60μm. The application of a low-micro-vibration piston body in a linear compressor in this embodiment 1 is specifically as follows: the inner diameter of the cylinder 2 of the linear compressor is D, and the piston body 1 is located in the cylinder 2.

[0031] See also Figure 7 , the gas leakage rate caused by the gap (i.e. the gap between the piston body 1 and the wall side of the cylinder 2) is proportional to the cube of the gap between the piston body 1 and the cylinder 2. When the gap between the piston body 1 and the cylinder 2 is less than 20μm, the gas leakage rate is small and the performance change is not obvious. When the gap between the piston body 1 and the cylinder 2 is greater than 20μm, the gas leakage rate increases rapidly and the compressor performance is significantly reduced. Considering the smooth operation of the piston body 1, the gap between the piston body 1 and the cylinder 2 should be greater than 5μm. Therefore, it is recommended that the diameter difference between the non-tapered area diameter D2 of the piston body 1 and the inner diameter D of the cylinder 2 be in the range of 10μm to 40μm.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A low-vibration piston body, characterized in that: The piston body (1) is a cylinder with a tapered end.

2. A low-micro-vibration piston body according to claim 1, characterized in that: The length of the piston body (1) includes the length L1 of the tapered region and the length L2 of the non-tapered region, where L1:L2=1±0.

5.

3. A low-micro-vibration piston body according to claim 2, characterized in that: The diameter D1 of the tapered end of the piston body (1) is smaller than the diameter D2 of the non-tapered region of the piston body (1), and the difference between the two diameters is in the range of 10 to 60 μm.

4. Application of a low-micro-vibration piston body in a linear compressor, using the low-micro-vibration piston body according to claim 3, characterized in that: The inner diameter of the cylinder (2) of the linear compressor is D, the piston body (1) is located in the cylinder (2), and the diameter difference between the non-tapered area diameter D2 of the piston body (1) and the inner diameter D of the cylinder (2) is in the range of 10 μm to 40 μm.

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