Two-stage oil-free piston type air compressor and railway vehicle

Abstract

The utility model relates to the technical field of air compressors, in particular to a two-stage oil-free piston type air compressor and a railway vehicle. According to the two-stage oil-free piston type air compressor, a first low-pressure cavity, a second low-pressure cavity, a first high-pressure cavity and a second high-pressure cavity are formed in an air cylinder, the axis of the first low-pressure cavity, the axis of the second low-pressure cavity, the axis of the first high-pressure cavity and the axis of the second high-pressure cavity are parallel to one another and are perpendicular to a first straight line, and meanwhile the axis of the first high-pressure cavity is perpendicular to a second straight line. The first low-pressure cavity and the second low-pressure cavity are distributed on one side of the first straight line, and the first high-pressure cavity and the second high-pressure cavity are distributed on the other side of the first straight line. According to the utility model, the vibration generated by the movement of each low-pressure piston assembly is offset by the vibration generated by the high-pressure piston assembly corresponding to the low-pressure piston assembly, so that the vibration of the air compressor caused by the reciprocating movement of the high-pressure piston assembly and the low-pressure piston assembly is reduced.

Description

Technical Field

[0001] This utility model relates to the field of air compressor technology, and in particular to a two-stage oil-free piston air compressor and a rail vehicle. Background Technology

[0002] For example, patent document CN209414074U discloses a prior art air compressor in which the low-pressure piston chamber for accommodating the low-pressure piston assembly and the high-pressure piston chamber for accommodating the high-pressure piston assembly are both distributed on the same side relative to the output shaft of the motor. This results in the vibration generated by the reciprocating motion of the low-pressure piston assembly and the vibration generated by the reciprocating motion of the high-pressure piston assembly being unable to cancel each other out. The vibration generated by the reciprocating motion of the low-pressure piston assembly and the vibration generated by the reciprocating motion of the high-pressure piston assembly act on the air compressor itself at the same time, making the overall vibration of the air compressor strong. Since the air compressor is usually installed on the chassis below the driver's cab, this also leads to a reduction in the driver's riding comfort.

[0003] Therefore, the technical problem in the prior art is how to reduce the vibration of the air compressor caused by the reciprocating motion of the high and low pressure piston assemblies. Utility Model Content

[0004] To address the technical problem of reducing air compressor vibration caused by the reciprocating motion of high and low pressure piston assemblies in existing technologies, this utility model provides a two-stage oil-free piston air compressor and a rail vehicle.

[0005] This utility model is achieved through the following technical solution:

[0006] A two-stage oil-free piston air compressor includes a motor and a cylinder. The motor housing is connected to the cylinder, and a crankshaft is installed inside the cylinder. The output shaft of the motor is used to drive the crankshaft to rotate, and the output shaft of the motor extends along a first straight line.

[0007] The cylinder is provided with a first low-pressure chamber, a second low-pressure chamber, a first high-pressure chamber, and a second high-pressure chamber. The axes of the first low-pressure chamber, the second low-pressure chamber, the first high-pressure chamber, and the second high-pressure chamber are all parallel to each other and perpendicular to the first straight line. Meanwhile, the first low-pressure chamber and the second low-pressure chamber are distributed on one side of the first straight line, and the first high-pressure chamber and the second high-pressure chamber are distributed on the other side of the first straight line.

[0008] The crankshaft includes a first shaft body and a second shaft body. The axis of the first shaft body is parallel to the axis of the second shaft body and there is a gap between them. Both extend along a first straight line.

[0009] The first low-pressure chamber, the second low-pressure chamber, the first high-pressure chamber, and the second high-pressure chamber are respectively equipped with a first low-pressure piston assembly, a second low-pressure piston assembly, a first high-pressure piston assembly, and a second high-pressure piston assembly; wherein, the first low-pressure connecting rod of the first low-pressure piston assembly and the first high-pressure connecting rod of the first high-pressure piston assembly are rotatably connected to the first shaft of the crankshaft, and the second low-pressure connecting rod of the second low-pressure piston assembly and the second high-pressure connecting rod of the second high-pressure piston assembly are rotatably connected to the second shaft of the crankshaft.

[0010] Furthermore, the cylinder includes a first cylinder head, a first valve plate, and a cylinder block;

[0011] An air intake is provided on one side of the cylinder block, and a cavity is provided inside the cylinder block to accommodate the crankshaft. The air intake is used to connect the atmosphere outside the cylinder to the cavity.

[0012] The first low-pressure chamber and the second low-pressure chamber are respectively constrained by the first valve plate and the cylinder body. A first one-way air intake valve is provided on the piston of the first low-pressure piston assembly. The first one-way air intake valve is used to unilaterally guide the air chamber toward the first low-pressure chamber. A second one-way air intake valve is provided on the piston of the second low-pressure piston assembly. The second one-way air intake valve is used to unilaterally guide the air chamber toward the second low-pressure chamber.

[0013] The first valve plate and the first cylinder head also jointly restrict the formation of a low-pressure air chamber. A first one-way valve and a second one-way valve are provided on the first valve plate. The first one-way valve is used to unilaterally guide the first low-pressure chamber toward the low-pressure air chamber, and the second one-way valve is used to unilaterally guide the second low-pressure chamber toward the low-pressure air chamber.

[0014] The cylinder also includes a second cylinder head and a second valve plate. The first high-pressure chamber and the second high-pressure chamber are formed by the second valve plate and the cylinder body, respectively. Furthermore, the second cylinder head and the second valve plate also jointly form a gas storage chamber and a high-pressure gas chamber. A third check valve and a fourth check valve are provided on the second valve plate. The third check valve is used to unilaterally guide the gas storage chamber toward the first high-pressure chamber, and the fourth check valve is used to unilaterally guide the gas storage chamber toward the second high-pressure chamber. A fifth check valve and a sixth check valve are also provided on the second valve plate. The fifth check valve is used to unilaterally guide the first high-pressure chamber toward the high-pressure gas chamber, and the sixth check valve is used to unilaterally guide the second high-pressure chamber toward the high-pressure gas chamber.

[0015] The two-stage oil-free reciprocating air compressor also includes an intercooler, the input end of which is connected to the low-pressure air chamber, and the output end of the input end of the intercooler is connected to the air storage chamber.

[0016] The two-stage oil-free reciprocating air compressor also includes an aftercooler, the input end of which is connected to the high-pressure air chamber;

[0017] The two-stage oil-free reciprocating air compressor has a compressed air passage, an air inlet, an air cavity, a first low-pressure cavity or a second low-pressure cavity, a low-pressure air cavity, a cooling cavity of an intercooler, an air storage cavity, a first high-pressure cavity or a second high-pressure cavity, a high-pressure air cavity, and a cooling cavity of an aftercooler connected in sequence, and each of these is a component of the compressed air passage. The output end of the aftercooler is used to output the two-stage compressed air.

[0018] Furthermore, the housings of the intercooler and the aftercooler are connected and jointly mounted on one side of the cylinder.

[0019] Furthermore, it also includes couplings, which are used to connect the crankshaft and the motor shaft;

[0020] The first section is the part of the coupling that is connected to the crankshaft, and the second section is the part of the crankshaft that is connected to the coupling. The second section is provided with a coaxial mounting groove, and the first section extends into the mounting groove.

[0021] A spring is installed inside the mounting slot. One end of the spring abuts against the bottom wall of the mounting slot, and the other end abuts against the side face of the first section facing the crankshaft.

[0022] Furthermore, the mounting groove includes a large-diameter groove and a small-diameter groove arranged coaxially, and a stepped surface is provided at the junction of the large-diameter groove and the small-diameter groove. The end face of the first section facing the crankshaft is restricted outside the small-diameter groove by the stepped surface.

[0023] A wear-resistant bushing is rotatably fitted on the outer circumference of the first section. The first section with the wear-resistant bushing extends deep into the large-diameter groove, and the groove wall of the large-diameter groove restricts the radial movement of the first section through the wear-resistant bushing.

[0024] The spring is set in the small-diameter groove. Along the radial direction of the spring, the spring is constrained by the groove wall and is coaxial with the small-diameter groove.

[0025] Furthermore, it also includes an intake filter and an intake pipe. The intake filter is connected to the intake port through the intake pipe and is located on the main body side of the motor.

[0026] Furthermore, a first damping pad and a second damping pad are provided on the motor housing, and a third damping pad and a fourth damping pad are provided on the outer wall of the cylinder. The upper surfaces of the first damping pad, the second damping pad, the third damping pad, and the fourth damping pad are respectively on the same preset plane, which is distributed on one side of the first straight line.

[0027] Furthermore, a rail vehicle is proposed, which includes the aforementioned two-stage oil-free piston air compressor.

[0028] Compared with existing technologies, the advantages of this utility model are:

[0029] 1. In this utility model, the first low-pressure chamber and the first high-pressure chamber, and the second low-pressure chamber and the second high-pressure chamber are respectively distributed on both sides of the output shaft of the motor, and the axes of the first low-pressure chamber, the first high-pressure chamber, the second low-pressure chamber, and the second high-pressure chamber are parallel to each other. This results in the following: during the operation of the air compressor, the movement of the low-pressure piston assembly in each low-pressure chamber is parallel to and opposite to the movement of the high-pressure piston assembly in its corresponding high-pressure chamber. For example, when the first low-pressure piston assembly in the first low-pressure chamber moves toward the first straight line, the first high-pressure piston assembly in the first high-pressure chamber also moves synchronously toward the first straight line. This results in the vibration generated by the movement of each low-pressure piston assembly being canceled out by the vibration generated by its corresponding high-pressure piston assembly, thereby reducing the air compressor vibration caused by the reciprocating motion of the high and low-pressure piston assemblies and further improving the driver's comfort.

[0030] 2. In this utility model, the outer shell of the intercooler and the outer shell of the aftercooler are connected and jointly installed on one side of the cylinder. This facilitates simultaneous inspection and maintenance of both the intercooler and the aftercooler during later maintenance.

[0031] 3. In this utility model, the spring is set between the coupling and the crankshaft, so that the coupling and the crankshaft are in elastic contact along the axial direction of the crankshaft. This avoids damage caused by excessive axial stress between the coupling and the crankshaft during installation or use, and extends the service life of the coupling and the crankshaft.

[0032] 4. Since the first section extends into the mounting groove for connection in this utility model, compared with the air compressor of the prior art, this utility model also shortens the axial connection length between the coupling and the crankshaft, and further reduces the overall axial dimension of the air compressor.

[0033] 5. In this utility model, an anti-wear bushing is provided on the outer side of the first section of the coupling, so that during the axial rotation of the first section in the large diameter groove, the first section contacts the inner wall of the large diameter groove through the anti-wear bushing, avoiding direct contact between the outer circumference of the first section and the inner wall of the large diameter groove, reducing the amount of wear and consumption of the outer circumference of the first section by the inner wall of the large diameter groove, and extending the service life of the coupling.

[0034] 6. In this utility model, the air intake filter filters the air entering the air intake port, ensuring the cleanliness of the air entering the air compressor from the air intake port.

[0035] 7. In this utility model, the air intake filter is located on the main body side of the motor, which makes it convenient to inspect the air intake filter and the main body of the motor at the same time during maintenance.

[0036] 8. When the two-stage oil-free piston air compressor of this utility model is installed on the chassis below the driver's cab by fasteners such as bolts, the first damping pad, the second damping pad, the third damping pad, and the fourth damping pad play the role of reducing the vibration force between the cylinder and the chassis, as well as between the motor housing and the chassis. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the two-stage oil-free piston air compressor of this utility model;

[0038] Figure 2 for Figure 1 A sectional view;

[0039] Figure 3 for Figure 1 A sectional view;

[0040] Figure 4 for Figure 3 A magnified structural diagram of the central circle region.

[0041] The diagram shows the following components: motor (1), cylinder (2), first cylinder head (201), first valve plate (202), cylinder block (203), second cylinder head (204), second valve plate (205), crankshaft (3), first shaft (301), second shaft (302), first low-pressure chamber (4), second low-pressure chamber (5), first high-pressure chamber (6), second high-pressure chamber (7), first low-pressure piston assembly (8), second low-pressure piston assembly (9), first high-pressure piston assembly (10), and second high-pressure piston assembly (11).

[0042] First one-way intake valve (12), cavity (13), second one-way intake valve (14), low-pressure air chamber (15), first one-way valve (16), second one-way valve (17), air storage chamber (18), high-pressure air chamber (19), third one-way valve (20), fourth one-way valve (21), intercooler (22), aftercooler (23), air inlet (24), coupling (25), first section (26), second section (27), mounting groove (28), spring (29), large diameter groove (30), small diameter groove (31), anti-wear bushing (32), intake filter (33), intake pipe (34), first shock absorber (35), second shock absorber (36), third shock absorber (37), fourth shock absorber (38). Detailed Implementation

[0043] The following detailed, non-limiting description of the utility model's technical solution, in conjunction with preferred embodiments and accompanying drawings, is provided. In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0044] Example 1

[0045] like Figures 1-3 As shown, this embodiment proposes a two-stage oil-free piston air compressor, which includes a motor 1 and a cylinder 2. The housing of the motor 1 is connected to the cylinder 2. A crankshaft 3 is disposed inside the cylinder 2. The output shaft of the motor 1 is used to drive the crankshaft 3 to rotate. The output shaft of the motor 1 extends along a first straight line. A first low-pressure chamber 4, a second low-pressure chamber 5, a first high-pressure chamber 6, and a second high-pressure chamber 7 are disposed inside the cylinder 2. The axes of the first low-pressure chamber 4, the second low-pressure chamber 5, the first high-pressure chamber 6, and the second high-pressure chamber 7 are all parallel to each other and perpendicular to the first straight line. At the same time, the first low-pressure chamber 4 and the second low-pressure chamber 5 are distributed on one side of the first straight line, and the first high-pressure chamber 6 and the second high-pressure chamber 7 are distributed on the other side of the first straight line. The crankshaft 3 includes a first shaft body. The crankshaft 301 and the second shaft 302 are parallel to each other and have a gap, and both extend along a first straight line. The first low-pressure chamber 4, the second low-pressure chamber 5, the first high-pressure chamber 6, and the second high-pressure chamber 7 are respectively equipped with a first low-pressure piston assembly 8, a second low-pressure piston assembly 9, a first high-pressure piston assembly 10, and a second high-pressure piston assembly 11. The first low-pressure connecting rod of the first low-pressure piston assembly 8 and the first high-pressure connecting rod of the first high-pressure piston assembly 10 are rotatably connected to the first shaft 301 of the crankshaft 3, and the second low-pressure connecting rod of the second low-pressure piston assembly 9 and the second high-pressure connecting rod of the second high-pressure piston assembly 11 are rotatably connected to the second shaft 302 of the crankshaft 3.

[0046] For example, patent document CN209414074U discloses a prior art air compressor in which the low-pressure piston chamber for accommodating the low-pressure piston assembly and the high-pressure piston chamber for accommodating the high-pressure piston assembly are both distributed on the same side relative to the output shaft of the motor. This results in the vibration generated by the reciprocating motion of the low-pressure piston assembly and the vibration generated by the reciprocating motion of the high-pressure piston assembly being unable to cancel each other out. The vibration generated by the reciprocating motion of the low-pressure piston assembly and the vibration generated by the reciprocating motion of the high-pressure piston assembly act on the air compressor itself at the same time, making the overall vibration of the air compressor strong. Since the air compressor is usually installed on the chassis below the driver's cab, this also leads to a reduction in the driver's riding comfort.

[0047] In this embodiment, the first low-pressure chamber 4 and the first high-pressure chamber 6, and the second low-pressure chamber 5 and the second high-pressure chamber 7 are respectively distributed on both sides of the motor's output shaft. Furthermore, the axes of the first low-pressure chamber 4, the first high-pressure chamber 6, the second low-pressure chamber 5, and the second high-pressure chamber 7 are parallel to each other. This results in the following situation during the operation of the air compressor: the movement of the low-pressure piston assembly in each low-pressure chamber is parallel to and opposite to the movement of the high-pressure piston assembly in its corresponding high-pressure chamber. For example, when the first low-pressure piston assembly 8 in the first low-pressure chamber 4 moves toward the first straight line, the first high-pressure piston assembly 10 in the first high-pressure chamber 6 also moves synchronously toward the first straight line. This results in the vibration generated by the movement of each low-pressure piston assembly being canceled out by the vibration generated by its corresponding high-pressure piston assembly, thereby reducing the air compressor vibration caused by the reciprocating motion of the high and low-pressure piston assemblies and further improving the driver's comfort.

[0048] The air compressor in this embodiment is a two-stage compression oil-free reciprocating air compressor. The compressed air passage of the air compressor in this embodiment is arranged as follows:

[0049] like Figures 1-3As shown, the cylinder 2 includes a first cylinder head 201, a first valve plate 202, and a cylinder body 203. An air inlet 24 is provided on one side of the cylinder body 203, and a cavity 13 is provided inside the cylinder body 203 to accommodate the crankshaft 3. The air inlet 24 is used to connect the air outside the cylinder 2 with the cavity 13. A first low-pressure chamber 4 and a second low-pressure chamber 5 are formed by the first valve plate 202 and the cylinder body 203, respectively. A first one-way intake valve 12 is provided on the piston of the first low-pressure piston assembly 8, which is used to unidirectionally guide the cavity 13 towards the first low-pressure chamber 4. A second one-way intake valve 14 is provided on the piston of the second low-pressure piston assembly 9. The intake valve 14 is used to unidirectionally guide the air cavity 13 toward the second low-pressure chamber 5; the first valve plate 202 and the first cylinder head 201 also jointly restrict the formation of the low-pressure air chamber 15. A first one-way valve 16 and a second one-way valve 17 are provided on the first valve plate 202, wherein the first one-way valve 16 is used to unidirectionally guide the first low-pressure chamber 4 toward the low-pressure air chamber 15, and the second one-way valve 17 is used to unidirectionally guide the second low-pressure chamber 5 toward the low-pressure air chamber 15; the cylinder 2 also includes a second cylinder head 204 and a second valve plate 205. The first high-pressure chamber 6 and the second high-pressure chamber 7 are respectively restricted and formed by the second valve plate 205 and the cylinder body 203, and the second cylinder head 204 and the second valve plate 205 are also restricted and formed by the second valve plate 205 and the cylinder body 203. 05 also jointly restricts the formation of the air storage chamber 18 and the high-pressure air chamber 19. A third one-way valve 20 and a fourth one-way valve 21 are provided on the second valve plate 205. The third one-way valve 20 is used to unilaterally guide the air storage chamber 18 towards the first high-pressure chamber 6, and the fourth one-way valve 21 is used to unilaterally guide the air storage chamber 18 towards the second high-pressure chamber 7. A fifth one-way valve and a sixth one-way valve (not shown in the figure) are also provided on the second valve plate 205. The fifth one-way valve is used to unilaterally guide the first high-pressure chamber 6 towards the high-pressure air chamber 19, and the sixth one-way valve is used to unilaterally guide the second high-pressure chamber 7 towards the high-pressure air chamber 19. The two-stage oil-free reciprocating air compressor also includes an intercooler 22. The input end of the compressor 2 is connected to the low-pressure air chamber 15, and the output end of the input end of the intercooler 22 is connected to the air storage chamber 18. The two-stage oil-free reciprocating air compressor also includes an aftercooler 23, the input end of which is connected to the high-pressure air chamber 19. The two-stage oil-free reciprocating air compressor has a compression air passage. The air inlet 24, the air chamber 13, the first low-pressure chamber 4 or the second low-pressure chamber 5, the low-pressure air chamber 15, the cooling chamber of the intercooler 22, the air storage chamber 18, the first high-pressure chamber 6 or the second high-pressure chamber 7, the high-pressure air chamber 19, and the cooling chamber of the aftercooler 23 are connected in sequence and are all components of the compression air passage. The output end of the aftercooler 23 is used to output the two-stage compressed air.

[0050] The structure and configuration of the aforementioned check valves are all existing technologies and will not be elaborated upon here.

[0051] In use, outside air enters cavity 13 through air inlet 24. The first low-pressure piston assembly 8 moves to the lower dead center in the first low-pressure chamber 4. Gas in cavity 13 enters the first low-pressure chamber 4 through the first one-way air inlet valve 12. The first low-pressure piston assembly 8 moves to the upper dead center in the first low-pressure chamber 4, compressing the air for the first time. The compressed air enters the low-pressure air chamber 15 through the first one-way valve 16, undergoes the first cooling through the intercooler 22, and then enters the storage chamber 18. The first high-pressure piston assembly 10 moves to the lower dead center in the first high-pressure chamber 6. Air enters the first high-pressure chamber 6 through the storage chamber 18 through the third one-way valve 20. The first high-pressure piston assembly 10 moves to the upper dead center in the first high-pressure chamber 6, where the air is compressed for the second time. The air flows to the high-pressure air chamber 19 through the fifth one-way valve. The air in the high-pressure air chamber 19 enters the aftercooler 23 through the pipeline for the second cooling, and then is output to the air storage tank through the output end of the aftercooler 23.

[0052] The previous section describes the path of gas through inlet 24, cavity 13, first low-pressure cavity 4, low-pressure gas cavity 15, cooling cavity of intercooler 22, gas storage cavity 18, first high-pressure cavity 6, high-pressure gas cavity 19, and aftercooler 23. There is another path: inlet 24, cavity 13, second low-pressure cavity 5, low-pressure gas cavity 15, cooling cavity of intercooler 22, gas storage cavity 18, second high-pressure cavity 7, high-pressure gas cavity 19, and aftercooler 23. This path is similar to the one in the previous section and will not be described in detail here.

[0053] Preferably, in this embodiment, the housings of the intercooler 22 and the aftercooler 23 are connected and jointly installed on one side of the cylinder 2. This facilitates simultaneous maintenance of both the intercooler 22 and the aftercooler 23 during later maintenance.

[0054] like Figures 2-4 As shown, in this further embodiment, the two-stage oil-free piston air compressor also includes a coupling 25, which is used to connect the crankshaft 3 and the motor 1 shaft. The section of the coupling 25 used to connect with the crankshaft 3 is a first section 26, and the section of the crankshaft 3 used to connect with the coupling 25 is a second section 27. The second section 27 is provided with a coaxial mounting groove 28, and the first section 26 extends into the mounting groove 28. A spring 29 is provided in the mounting groove 28, with one end of the spring 29 abutting against the bottom wall of the mounting groove 28 and the other end abutting against the side end face of the first section 26 facing the crankshaft 3.

[0055] In this embodiment, the spring 29 is disposed between the coupling 25 and the crankshaft 3, so that the coupling 25 and the crankshaft 3 are in elastic contact along the axial direction of the crankshaft 3. This avoids damage caused by excessive axial stress between the coupling 25 and the crankshaft 3 during installation or use, and extends the service life of the coupling 25 and the crankshaft 3.

[0056] Meanwhile, since in this embodiment, the first segment 26 extends into the mounting groove 28 for connection, compared with the air compressor of the prior art, this embodiment also shortens the axial connection length between the coupling 25 and the crankshaft 3, further reducing the overall axial dimension of the air compressor.

[0057] like Figures 2-4 As shown, specifically, the mounting groove 28 includes a large-diameter groove 30 and a small-diameter groove 31 arranged coaxially. A stepped surface is provided at the junction of the large-diameter groove 30 and the small-diameter groove 31. The end face of the first segment 26 facing the crankshaft 3 is restricted outside the small-diameter groove 31 by the stepped surface. A wear-resistant bushing 32 is coaxially and rotatably fitted on the outer circumferential surface of the first segment 26. The first segment 26 with the wear-resistant bushing 32 extends deep into the large-diameter groove 30. Along the radial direction of the first segment 26, the groove wall of the large-diameter groove 30 restricts the radial movement of the first segment 26 by the wear-resistant bushing 32. A spring 29 is disposed in the small-diameter groove 31. Along the radial direction of the spring 29, the spring 29 is restricted by the groove wall of the small-diameter groove 31 and is coaxial with the small-diameter groove 31.

[0058] In this embodiment, the wear-resistant bushing 32 is an annular bushing made of one of the wear-resistant materials in the prior art, such as a ceramic bushing; specifically, the first segment 26 and the inner ring of the wear-resistant bushing 32 are clearance fits and can rotate freely, while the outer ring of the wear-resistant bushing 32 and the groove wall of the large diameter groove 30 are interference fits and are relatively fixed.

[0059] In this embodiment, an anti-wear bushing 32 is fitted on the outer side of the first section 26 of the coupling 25, so that during the axial rotation of the first section 26 within the large diameter groove 30, the first section 26 contacts the inner wall of the large diameter groove 30 through the anti-wear bushing 32, thereby preventing the outer circumferential surface of the first section 26 from directly contacting the inner wall of the large diameter groove 30, reducing the amount of wear and tear on the outer circumferential surface of the first section 26 caused by the inner wall of the large diameter groove 30, and extending the service life of the coupling 25.

[0060] Furthermore, the two-stage oil-free piston air compressor of this embodiment also includes an intake filter 33 and an intake pipe 34. The intake filter 33 is connected to the intake port 24 through the intake pipe 34, and the intake filter 33 is disposed on the main unit side of the motor 1.

[0061] In this embodiment, the air intake filter 33 filters the air entering the air intake port 24, ensuring the cleanliness of the air entering the air compressor through the air intake port 24.

[0062] In this embodiment, the intake filter 33 is located on the main unit side of the motor 1, which facilitates simultaneous maintenance of both the intake filter 33 and the main unit of the motor 1.

[0063] like Figure 1As shown, the motor 1 housing is further provided with a first damping pad 35 and a second damping pad 36, and the cylinder 2 outer wall is provided with a third damping pad 37 and a fourth damping pad 38. The upper surfaces of the first damping pad 35, the second damping pad 36, the third damping pad 37, and the fourth damping pad 38 are respectively on the same preset plane, which is distributed on one side of the first straight line.

[0064] The first damping pad 35, the second damping pad 36, the third damping pad 37, and the fourth damping pad 38 are all made of elastic materials, such as rubber.

[0065] In this embodiment, when the two-stage oilless piston air compressor is installed on the chassis below the driver's cab using fasteners such as bolts, the first damping pad 35, the second damping pad 36, the third damping pad 37, and the fourth damping pad 38 serve to reduce the vibration force between the cylinder 2 and the chassis, as well as between the motor 1 housing and the chassis.

[0066] Example 2

[0067] This embodiment proposes a rail vehicle that includes the two-stage oil-free piston air compressor mentioned in Embodiment 1.

[0068] The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A two-stage oil-free reciprocating air compressor, characterized in that, It includes a motor (1) and a cylinder (2). The housing of the motor (1) is connected to the cylinder (2). A crankshaft (3) is installed inside the cylinder (2). The output shaft of the motor (1) is used to drive the crankshaft (3) to rotate. The output shaft of the motor (1) extends along a first straight line. A first low-pressure chamber (4), a second low-pressure chamber (5), a first high-pressure chamber (6), and a second high-pressure chamber (7) are provided in the cylinder (2). The axes of the first low-pressure chamber (4), the second low-pressure chamber (5), the first high-pressure chamber (6), and the second high-pressure chamber (7) are all parallel to each other and perpendicular to the first straight line. Meanwhile, the first low-pressure chamber (4) and the second low-pressure chamber (5) are distributed on one side of the first straight line, and the first high-pressure chamber (6) and the second high-pressure chamber (7) are distributed on the other side of the first straight line. The crankshaft (3) includes a first shaft body (301) and a second shaft body (302). The axis of the first shaft body (301) is parallel to the axis of the second shaft body (302) and there is a gap between them, and both extend along a first straight line. The first low-pressure chamber (4), the second low-pressure chamber (5), the first high-pressure chamber (6), and the second high-pressure chamber (7) are respectively equipped with a first low-pressure piston assembly (8), a second low-pressure piston assembly (9), a first high-pressure piston assembly (10), and a second high-pressure piston assembly (11); wherein the first low-pressure connecting rod of the first low-pressure piston assembly (8) and the first high-pressure connecting rod of the first high-pressure piston assembly (10) are rotatably connected to the first shaft (301) of the crankshaft (3), and the second low-pressure connecting rod of the second low-pressure piston assembly (9) and the second high-pressure connecting rod of the second high-pressure piston assembly (11) are rotatably connected to the second shaft (302) of the crankshaft (3).

2. The two-stage oil-free reciprocating air compressor according to claim 1, characterized in that, The cylinder (2) includes a first cylinder head (201), a first valve plate (202), and a cylinder block (203); An air inlet (24) is provided on one side of the cylinder block (203), and a cavity (13) is provided inside the cylinder block (203). The cavity (13) is used to accommodate the crankshaft (3), and the air inlet (24) is used to connect the atmosphere outside the cylinder (2) with the cavity (13). The first low-pressure chamber (4) and the second low-pressure chamber (5) are formed by the first valve plate (202) and the cylinder (203) respectively. A first one-way air intake valve (12) is provided on the piston of the first low-pressure piston assembly (8). The first one-way air intake valve (12) is used to unilaterally guide the cavity (13) toward the first low-pressure chamber (4). A second one-way air intake valve (14) is provided on the piston of the second low-pressure piston assembly (9). The second one-way air intake valve (14) is used to unilaterally guide the cavity (13) toward the second low-pressure chamber (5). The first valve plate (202) and the first cylinder head (201) also jointly restrict the formation of a low-pressure air chamber (15). A first one-way valve (16) and a second one-way valve (17) are provided on the first valve plate (202). The first one-way valve (16) is used to unilaterally guide the first low-pressure chamber (4) toward the low-pressure air chamber (15), and the second one-way valve (17) is used to unilaterally guide the second low-pressure chamber (5) toward the low-pressure air chamber (15). The cylinder (2) also includes a second cylinder head (204) and a second valve plate (205). The first high-pressure chamber (6) and the second high-pressure chamber (7) are respectively constrained by the second valve plate (205) and the cylinder body (203). Furthermore, the second cylinder head (204) and the second valve plate (205) also jointly constrain the formation of a gas storage chamber (18) and a high-pressure gas chamber (19). A third one-way valve (20) and a fourth one-way valve (21) are provided on the second valve plate (205). One-way valve (20) is used to unilaterally open the gas storage chamber (18) to the first high-pressure chamber (6), and the fourth one-way valve (21) is used to unilaterally open the gas storage chamber (18) to the second high-pressure chamber (7). A fifth one-way valve and a sixth one-way valve are also provided on the second valve plate (205). The fifth one-way valve is used to unilaterally open the first high-pressure chamber (6) to the high-pressure gas chamber (19), and the sixth one-way valve is used to unilaterally open the second high-pressure chamber (7) to the high-pressure gas chamber (19). The two-stage oil-free reciprocating air compressor also includes an intercooler (22), the input end of which is connected to the low-pressure air chamber (15), and the output end of the input end of the intercooler (22) is connected to the air storage chamber (18). The two-stage oil-free reciprocating air compressor also includes an aftercooler (23), the input end of which is connected to the high-pressure air chamber (19); The two-stage oilless piston air compressor has a compressed air passage, an air inlet (24), a cavity (13), a first low-pressure cavity (4) or a second low-pressure cavity (5), a low-pressure air cavity (15), a cooling cavity of an intercooler (22), an air storage cavity (18), a first high-pressure cavity (6) or a second high-pressure cavity (7), a high-pressure air cavity (19), and a cooling cavity of an aftercooler (23) connected in sequence, and each is a component of the compressed air passage. The output end of the aftercooler (23) is used to output the two-stage compressed air.

3. The two-stage oil-free reciprocating air compressor according to claim 2, characterized in that, The housing of the intercooler (22) and the housing of the aftercooler (23) are connected and are installed together on one side of the cylinder (2).

4. The two-stage oil-free reciprocating air compressor according to claim 2 or 3, characterized in that, It also includes a coupling (25) for connecting the crankshaft (3) and the motor (1) shaft; The first section (26) of the coupling (25) is used to connect with the crankshaft (3), and the second section (27) of the crankshaft (3) is used to connect with the coupling (25). The second section (27) is provided with a coaxial mounting groove (28), and the first section (26) extends into the mounting groove (28). A spring (29) is provided in the mounting groove (28). One end of the spring (29) abuts against the bottom wall of the mounting groove (28), and the other end abuts against the side end face of the first section (26) facing the crankshaft (3).

5. The two-stage oil-free reciprocating air compressor according to claim 4, characterized in that, The mounting slot (28) includes a large diameter slot (30) and a small diameter slot (31) arranged coaxially. A stepped surface is provided at the junction of the large diameter slot (30) and the small diameter slot (31). The end face of the first segment (26) facing the crankshaft (3) is restricted outside the small diameter slot (31) by the stepped surface. A wear-resistant bushing (32) is rotatably fitted on the outer circumferential surface of the first segment (26). The first segment (26) with the wear-resistant bushing (32) extends deep into the large diameter groove (30). Along the radial direction of the first segment (26), the groove wall of the large diameter groove (30) restricts the radial movement of the first segment (26) through the wear-resistant bushing (32). The spring (29) is set in the small diameter groove (31). Along the radial direction of the spring (29), the spring (29) is restricted by the groove wall of the small diameter groove (31) and is coaxial with the small diameter groove (31).

6. The two-stage oil-free reciprocating air compressor according to claim 2, characterized in that, It also includes an air intake filter (33) and an air intake pipe (34). The air intake filter (33) is connected to the air intake port (24) through the air intake pipe (34). The air intake filter (33) is located on the main body side of the motor (1).

7. The two-stage oil-free reciprocating air compressor according to claim 1, characterized in that, The motor (1) housing is provided with a first shock-absorbing pad (35) and a second shock-absorbing pad (36), and the cylinder (2) outer wall is provided with a third shock-absorbing pad (37) and a fourth shock-absorbing pad (38). The upper surfaces of the first shock-absorbing pad (35), the second shock-absorbing pad (36), the third shock-absorbing pad (37), and the fourth shock-absorbing pad (38) are respectively on the same preset plane, which is distributed on one side of the first straight line.

8. A rail vehicle, characterized in that, Includes the two-stage oil-free reciprocating air compressor as described in any one of claims 1-7.

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