Piston and oil-free piston electric air compressor with improved guide piston ring life

Abstract

The utility model discloses a kind of piston and oil-free piston type electric air compressor for improving the service life of guide piston ring, at least one annular or arc-shaped first groove is arranged between the upper and lower ends of guide piston ring groove, active expansion body with greater thermal expansion coefficient than the piston body is installed in the first groove, by the establishment of active expansion body, the priority worn part of guide piston ring is changed, powder medium can be stripped between the upper and lower ends of guide piston ring in corresponding position, and the powder medium is effectively guided into micro-network grooves, after the powder medium entering micro-network grooves is stripped, it can still fall into the micro annular groove of the outer circumferential surface of active expansion body corresponding guide piston ring, and in the reciprocating motion of new round, it enters micro-network grooves and forms friction lubrication, so as to reduce the stripping of guide piston ring caused by powder medium stripping again, improve the service life of guide piston ring. Furthermore, air compressor using the above piston is also provided.

Description

Technical Field

[0001] This utility model relates to the field of piston technology, specifically to a piston for an oil-free piston electric air compressor that can improve the life of the guide piston ring, and an oil-free piston electric air compressor using the piston. Background Technology

[0002] In existing oil-free reciprocating electric air compressors, the piston structure generally includes a piston body, guide piston rings, and a piston pin. The guide piston rings are located in guide piston ring grooves in the middle of the piston and cover both ends of the piston pin bore. The piston cylinder, which mates with the piston structure, typically has a cross-shaped micro-textured structure on its inner wall. This structure is designed to store the powdery medium shed from the friction between the guide piston rings and the inner wall of the piston cylinder, thus achieving lubrication. However, in existing piston structures, during the reciprocating motion, the upper and lower ends of the guide piston rings are often worn first, releasing powdery medium that fills the micro-textured grooves. With each reciprocating motion, some of the powdery medium in the grooves is released, and the guide piston ring surface is worn again. This cycle repeats, resulting in poor guide piston ring life. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a piston for improving the life of the guide piston ring, which includes a piston body, a guide piston ring groove formed on the piston body, and a guide piston ring installed in the guide piston ring groove; at least one annular or arc-shaped first groove is provided between the upper and lower ends of the guide piston ring groove, and an active expansion body with a thermal expansion coefficient greater than that of the piston body is installed in the first groove.

[0004] When the piston reciprocates, the friction between the guide piston ring and the inner wall of the piston cylinder generates heat, which is transferred to all parts of the piston. Because the active expansion body, with a coefficient of thermal expansion greater than that of the piston body, is installed in the first groove, its volume expansion is greater than that of the piston body. However, the expansion of the active expansion body towards the first groove is counteracted by the wall (aluminum alloy) of the first groove, and the force has little effect on the wall of the first groove. The guide piston ring is made of a softer material than the metal active expansion body, and the expansion direction of the active expansion body is mainly radial towards the guide piston ring. Due to the action of the active expansion body, the guide piston ring at the corresponding position protrudes radially. During the reciprocating motion, this protruding part of the guide piston ring is preferentially rubbed and peeled off, releasing the powder medium, which then enters the micro-textured grooves. Furthermore, when the micro-textured grooves contain enough powder medium peeled off from the guide piston ring, the outer circumferential surface of the guide piston ring completely adheres to the inner wall of the piston cylinder in a hot state, and the powder medium filling the micro-texture acts as a lubricant. When the entire machine is stopped or in a cold state, microscopic annular grooves are formed on the outer circumferential surface of the guide piston ring, which is pressed against by the active expander. At this time, the powder medium detached from the groove will preferentially enter the microscopic annular groove. With the reciprocating motion of the piston and the warm-up process, the powder medium in the microscopic annular groove will be pushed into the microscopic groove. It can be seen that by setting up the active expander, the preferential wear area of ​​the guide piston ring is changed, and the powder medium can be peeled off at the corresponding position between the upper and lower ends of the guide piston ring. The powder medium is effectively guided into the microscopic groove. After detaching, the powder medium that enters the microscopic groove can still fall into the microscopic annular groove on the outer circumferential surface of the guide piston ring corresponding to the active expander, and enter the microscopic groove in the microscopic groove during the new round of reciprocating motion to form a frictional lubrication effect. This reduces the re-detachment of the guide piston ring caused by the powder medium, thereby improving the service life of the guide piston ring.

[0005] Preferably, an annular first groove is provided at both the upper and lower ends of the piston pin hole.

[0006] Furthermore, a second annular groove is provided at both the upper and lower ends of the guide piston ring groove. The purpose of providing the second groove is to allow the upper and lower ends of the guide piston ring to expand into the second groove during thermal expansion in a hot-engine state, reducing expansion towards the inner wall of the piston cylinder, thereby avoiding wear at both ends of the guide piston ring and improving its service life; alternatively, reduced wear at both ends of the guide piston ring results in better sealing.

[0007] Furthermore, a sealing body located inside the piston pin hole is provided between both ends of the piston pin and the guide piston ring.

[0008] An oil-free piston electric air compressor includes the piston described above that improves the life of the guide piston rings. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the specific embodiments of this utility model, the drawings used in the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the piston of this utility model installed inside the piston cylinder;

[0011] Figure 2 yes Figure 1 Enlarged view of A in the middle;

[0012] Figure 3 This is a schematic diagram of the microstructure of the inner wall of the piston cylinder of this utility model;

[0013] Figure 4 yes Figure 1 A magnified schematic diagram of the hot state of component B;

[0014] Figure 5 yes Figure 1 A magnified cold-state diagram of B;

[0015] The reference numerals in the figure are as follows: 1-Guide piston ring groove; 2-Guide piston ring; 3-First groove; 4-Active expansion body; 5-Second groove; 6-Sealing body; 7-Piston cylinder; 8-Micro-texture; 9-Piston pin; 10-Groove; 11-Micro-annular groove. Detailed Implementation

[0016] The present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Other embodiments derived by those skilled in the art from the embodiments of the present invention without inventive effort are all within the scope of protection of the present invention.

[0017] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation 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.

[0018] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0019] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0020] Example 1

[0021] like Figure 1-3 As shown, this embodiment discloses a piston for improving the lifespan of a guide piston ring. It includes a piston body with a guide piston ring groove 1 for mounting a guide piston ring 2. At least one annular or arc-shaped first groove 3 is provided between the upper and lower ends of the guide piston ring groove 1. An active expansion body 4 with a thermal expansion coefficient greater than that of the piston body is installed within the first groove 3. Preferably, the active expansion body 4 does not extend beyond the first groove 3; in this embodiment, the active expansion body 4 just fills the first groove 3. The active expansion body 4 is preferably made of metal or a metal alloy. Since the piston body is generally made of aluminum alloy, the active expansion body 4 is preferably made of magnesium alloy with a thermal expansion coefficient greater than that of aluminum alloy. Of course, the material of the active expansion body 4 needs to be selected specifically based on the material of the piston body. Generally, a material with a thermal expansion coefficient slightly greater than that of the piston body is sufficient. If the difference is large, the placement of the active expansion body 4 in the first groove 3 needs to be adjusted, for example, by placing it at a distance from the groove opening.

[0022] As for the specific position of the first groove 3, it is mainly to avoid affecting the normal wear of the upper and lower ends of the guide piston ring 2. For example, the distance between the upper edge of the uppermost first groove 3 and the lower edge of the lowermost first groove 3 is four-fifths of the height of the guide piston ring groove 1, preferably one-half, and the distance between the upper and lower ends of this distance is equal to the distance between the upper and lower ends of the guide piston ring groove 1.

[0023] Preferably, an annular first groove 3 is provided at both the upper and lower ends of the piston pin hole, such as... Figure 1 and Figure 2 As shown.

[0024] Furthermore, an annular second groove 5 is provided at both the upper and lower ends of the guide piston ring groove 1. Specifically, the groove can be located on the sidewalls of the upper and lower ends of the guide piston ring groove 1, or on the sidewall between the upper and lower ends, preferably on the sidewall between the upper and lower ends. Figure 1 and Figure 2As shown.

[0025] A sealing body 6 is provided between the two ends of the piston pin 9 and the guide piston pin ring 2, and is located in the piston pin hole. The sealing body 6 is made of materials such as polytetrafluoroethylene or rubber.

[0026] As for the micro-network pattern 8 formed on the inner wall of the piston cylinder 7, as shown in Figure 3, the micro-network pattern 8 is preferably a cross-network structure, in which a groove 10 structure is formed. The above structure is an existing structure, and will not be described in detail.

[0027] Example 2

[0028] This embodiment discloses an oil-free piston electric air compressor, which includes the piston described in Embodiment 1 for improving the life of the guide piston ring.

[0029] The usage process of this utility model is as follows:

[0030] refer to Figure 4 and Figure 5 When the piston reciprocates, friction generates heat, causing the active expansion body 4 to expand beyond the piston body. This pushes the guide piston ring 2 against the inner wall of the piston cylinder 7. During the movement, the guide piston ring 7 at the protrusion is preferentially rubbed and peeled off, allowing powdered media to enter the grooves 10 in the micro-texture 8, thus achieving lubrication. When the piston stops moving, the active expansion body 4 cools and retracts. The outer circumferential surface of the guide piston ring 2, which is pushed out by the active expansion body 4, forms a micro-annular groove 11 due to friction. At this time, the powdered media in the grooves 10 of the micro-texture 8 detaches from the grooves 10 and preferentially enters the micro-annular groove 11. With the piston's reciprocating motion and heat generation, the powdered media in the micro-annular groove 10 is pushed into the grooves 10 of the micro-texture 8, thus creating a cycle.

[0031] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A piston for increasing the life of a pilot piston ring, characterized in that, The piston body includes a piston body with a guide piston ring groove formed thereon, and a guide piston ring is installed in the guide piston ring groove. At least one annular or arc-shaped first groove is provided between the upper and lower ends of the guide piston ring groove, and an active expansion body with a thermal expansion coefficient greater than that of the piston body is installed in the first groove.

2. The piston of claim 1 wherein, An annular first groove is provided at both the upper and lower ends of the piston pin hole.

3. The piston of claim 1 or 2, wherein, A second annular groove is provided at both the upper and lower ends of the guide piston ring groove.

4. The piston of claim 3 wherein, A sealing body located inside the piston pin hole is provided between the two ends of the piston pin and the guide piston ring.

5. An oil-free piston electric air compressor characterized by, It includes the piston with improved guide piston ring life as described in any one of claims 1-4.

Images