Novel piston type air cylinder

Abstract

According to the novel piston type air cylinder, the oil ducts are arranged in the crankshaft and the connecting rod, and lubricating oil of an external lubricating oil source is conveyed to the connecting rod nozzle formed in the small end of the connecting rod and sprayed into the inner cavity of the piston to be atomized. The atomized lubricating oil enters a cylinder cavity through an oil outlet hole near the bottom of the piston to lubricate the piston and the inner wall of the cylinder, so that the friction force between the piston and the inner wall of the cylinder is reduced. According to the utility model, the rotating gap between the large end of the connecting rod and the crankshaft is creatively contained in the oil path at the joint of the crankshaft and the connecting rod, so that the problem that the oil path is cut off during rotating connection is solved. By adopting a brand-new scheme of feeding oil from the interior of the piston, an oil feeding point moves in the cylinder along with the piston, and the defects that in a piston type cylinder in the prior art, oil is fed to the piston and the inner wall of the cylinder from the exterior of the piston only through a fixed point arranged on the wall surface of the cylinder, and an effective oil film is difficult to form because the oil cannot move along with the piston; and poor lubrication is easily caused.

Description

Technical Field

[0001] The utility model relates to the technical field of cylinders, in particular to a novel piston cylinder. Background Art

[0002] The piston cylinder includes a cylinder body and a piston matching the cylinder cavity. In the cylinder cavity, an expandable and compressible working medium, usually a gas, is set. When working, the expansion and contraction of the working medium in the cylinder cavity drives the piston to move back and forth along the inner wall of the cylinder. Specifically, when the working medium is subjected to heat, such as an explosion, it will expand and deform, push the piston to move horizontally, and expand the capacity of the cylinder sealing cavity; when the medium cools and contracts, the pressure in the sealing cavity decreases, and the reset mechanism works at the same time, the piston moves in the opposite direction, reducing the capacity of the sealing cavity and balancing the pressure in the sealing cavity, thus forming a reciprocating motion.

[0003] The step-type cylinder includes a two-stage sealed cylinder (one large and one small) and two pistons that match the inner diameters of the corresponding cylinders. The basic structure of the existing step-type cylinder piston is as follows: Figure 1 As shown, it includes two-stage pistons, each stage piston includes a ring portion with a piston ring seal ring transversely sleeved thereon and a cylindrical guide portion, and the free end of the outermost guide portion is rotatably connected to the small end of the connecting rod through a piston pin 50. Among them, the diameter of the first-stage piston is larger than that of the second-stage piston, the first-stage guide portion 55 is arranged below the first-stage ring portion 54, the second-stage guide portion 57 is arranged below the second-stage ring portion 56, and the piston pin 50 is connected to the small end of the connecting rod at the second-stage guide portion 57.

[0004] When the piston moves back and forth in the cylinder, the guide part is in close contact with the inner wall of the cylinder, which generates great sliding friction. This not only wastes energy and reduces the efficiency of the cylinder, but also causes deformation due to severe heat generation, reduces the sealing of the cylinder, and may damage the cylinder and reduce the service life of the cylinder. Therefore, when the cylinder is working, it is necessary to continuously add lubricating oil between the piston and the inner wall of the cylinder.

[0005] In the prior art, the first-stage cylinder is basically lubricated by fixed-point forced oil injection, that is, a fixed oil supply port is set on the inner wall surface of the first-stage cylinder to feed lubricating oil into the cylinder cavity, and a group of oil return holes 53 are arranged radially under the second ring portion of the first-stage piston, so that the lubricating oil scraped off by the first two piston rings returns to the oil pool in the crankcase from the oil return holes 53.

[0006] The structure and lubrication method of this differential piston makes it difficult to form an effective oil film between the inner wall of the cylinder and the piston ring and the piston guide, resulting in poor lubrication and even dry friction. Therefore, in actual test operation, the first-stage cylinder often has multiple cylinder pulling phenomena, that is, the piston scratches the inner wall of the cylinder, which is manifested as obvious longitudinal mechanical scratches and scrapes on the inner wall of the cylinder within the range of motion of the piston ring. This seriously affects the working effect and service life of the cylinder. Therefore, the existing technology needs to be further improved and enhanced. Summary of the invention

[0007] The utility model aims to provide a novel piston type cylinder, which can provide effective lubrication for the cylinder and the piston to reduce the friction in the cylinder.

[0008] To achieve the above-mentioned purpose, the utility model provides a novel piston cylinder, comprising at least one cylinder cavity and a hollow piston adapted to the cylinder cavity, the guide portion of the piston being rotatably connected to a small end of a connecting rod through a piston pin, and the large end of the connecting rod being rotatably connected to a crankshaft; an oil inlet is provided at the end of the crankshaft, connected to an external lubricating oil source; a hollow crankshaft oil passage is provided inside the crankshaft along a substantially axial direction, the crankshaft oil passage at least extending to the position of the large end, and connecting the annular gap between the large end and the crankshaft through at least one crankshaft hole; a hollow connecting rod oil passage is provided inside the connecting rod from the large end to the small end, one end of the connecting rod oil passage being connected to the gap; the other end of the connecting rod oil passage is a nozzle, the nozzle opening being on the side of the small end facing the piston inner cavity; the piston inner cavity is provided with at least one oil outlet near the bottom away from the small end, for outputting lubricating oil gas to the cylinder cavity.

[0009] The new piston cylinder of the utility model is provided with oil passages inside the crankshaft and the connecting rod, and lubricating oil is fed in from an external lubricating oil source, and the lubricating oil is sprayed into the inner cavity of the piston through the connecting rod nozzle provided on the small end of the connecting rod for atomization. The atomized lubricating oil then enters the cylinder cavity through the oil outlet hole near the bottom of the piston, lubricates the piston and the inner wall of the cylinder, and reduces the friction between the piston and the inner wall of the cylinder. The utility model creatively incorporates the rotational clearance between the big end and the crankshaft into the oil passage at the connection between the crankshaft and the connecting rod, and solves the problem of the oil passage being cut off during the rotation connection. The utility model adopts a brand-new scheme of supplying oil from the inside of the piston, and the oil supply point moves with the piston in the cylinder, which overcomes the disadvantage of the piston cylinder of the prior art that the piston and the inner wall of the cylinder are supplied with oil from the outside of the piston only through a fixed point provided on the wall of the cylinder, and therefore cannot move with the piston to form an effective oil film, which easily leads to poor lubrication.

[0010] Preferably, the oil outlet hole opens at the ring portion of the piston, and is used to output lubricating oil gas to at least the guide portion. The oil outlet hole is arranged on any wall surface of the piston, and can continuously provide lubricating oil gas to the cylinder cavity, but the ring portion is preferred, because when the oil outlet hole is arranged on the ring portion, the lubricating oil gas can directly contact the sealing ring of the ring portion and the outer wall surface of the guide portion, and form an oil film with the inner wall of the cylinder cavity, providing good full-course lubrication.

[0011] More preferably, the oil outlet hole opens at the junction of the ring part and the guide part. The oil outlet hole is arranged at the junction of the ring part and the guide part, especially the opening is toward the guide part, which can ensure that sufficient oil and gas lubrication can be provided to the ring part and the guide part at the same time, thereby reducing the sliding friction between the ring part and the guide part and the inner wall of the cylinder.

[0012] Preferably, the small head is sleeved with the piston pin through a copper sleeve, and a copper sleeve oil groove connecting the connecting rod oil passage and the connecting rod nozzle is opened along the general circumference of the piston pin on the side of the copper sleeve facing away from the piston pin. Because the copper sleeve and the small head are usually interference fit, that is, approximately fixedly connected without relative displacement, it is very convenient to directly set the copper sleeve oil groove on the outside of the copper sleeve to feed the lubricating oil into the connecting rod nozzle.

[0013] More preferably, the copper sleeve is provided with at least one diffusion groove along the width direction, and the diffusion groove is connected to the copper sleeve oil groove, and is used to provide lubricating oil between the copper sleeve and the piston to lubricate the rotation between the two. Because the small head is rotatably connected to the piston through the copper sleeve, there is a large rotational friction between the copper sleeve and the piston. The diffusion groove, especially the tree-shaped diffusion groove, is provided to obtain part of the lubricating oil from the copper sleeve oil groove, which can provide lubrication for the rotation between the copper sleeve and the piston.

[0014] In one embodiment, the piston pin is a hollow tube with openings at both ends, and the hollow tube is provided with at least one transparent radial oil hole for connecting the copper sleeve oil groove with the interior of the hollow tube. In this way, lubricating oil can also be provided from the piston pin to the cylinder cavity.

[0015] Preferably, the big head covers the crankshaft through a bearing, an annular bearing groove is provided between the bearing and the crankshaft, the crankshaft hole communicates with the crankshaft oil passage and the bearing groove; the connecting rod oil passage opens into the bearing groove. In the prior art cylinder, the big head is usually wrapped with a bearing, the bearing is fixed to the big head of the connecting rod, and the crankshaft rotates in the bearing, so the crankshaft oil passage transports lubricating oil to the bearing groove through the crankshaft hole, and then transports lubricating oil to the connecting rod oil passage through the bearing groove. At the same time, the lubricating oil in the bearing groove can also provide lubrication for the rotation between the bearing and the crankshaft.

[0016] Preferably, a fixed oil inlet is also included, and the fixed oil inlet is opened on the inner wall surface of the cylinder cavity, and is used to input lubricating oil into the cylinder cavity. The fixed oil inlet is provided to transport lubricating oil from the outside to the inner wall of the cylinder and the piston, which further ensures the lubrication effect and prevents the cylinder from pulling.

[0017] More preferably, the cylinder cavity includes a primary cylinder with a larger inner diameter and a secondary cylinder with a smaller inner diameter, the inner cavities of the primary cylinder and the secondary cylinder are interconnected, and the fixed oil inlet opens on the inner wall surface of the primary cylinder. For a differential cylinder, a fixed oil inlet is only provided on the inner wall surface of the primary cylinder, and there is no need to provide a fixed oil inlet on the secondary cylinder, because the lubricating oil fed into the fixed oil inlet on the inner wall surface of the primary cylinder can flow into the secondary cylinder cavity to form a good oil film. At the same time, the piston pin at the connection between the secondary guide part and the connecting rod can also provide lubricating oil to the secondary cylinder cavity through the openings at both ends.

[0018] Preferably, a pressure pump is further included, connecting the lubricating oil source and the oil inlet. A pressure pump is arranged between the lubricating oil source and the oil inlet, and external lubricating oil is pressurized and injected into the oil inlet, and then sent to the connecting rod nozzle through the oil passage inside the crankshaft and the connecting rod. Under pressure, the lubricating oil will be sprayed into the piston cavity, collide with the bottom of the cavity, and be atomized to form a large amount of uniform oil mist, and then be input into the cylinder cavity through the oil outlet hole near the bottom to lubricate the piston and the inner wall of the cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a cylinder piston in the prior art;

[0020] Figure 2 This is a three-dimensional diagram of the overall structure of the piston cylinder of the utility model;

[0021] Figure 3 This is a cross-sectional view from a first angle of the piston cylinder of the utility model;

[0022] Figure 4 It is an enlarged side view of the connecting rod structure of the piston cylinder of the utility model;

[0023] Figure 5 This is an enlarged front view of the connecting rod structure of the piston cylinder of the utility model;

[0024] Figure 6 It is a cross-sectional view of the piston cylinder of the utility model at an angle of AA;

[0025] Figure 7 This is a schematic diagram of the piston structure of the piston cylinder of the utility model;

[0026] In the figure: 20-crankshaft, 21-oil inlet, 22-crankshaft oil channel, 23-crankshaft hole, 24-bearing, 25-bearing groove, 30-connecting rod, 31-connecting rod oil channel, 32-connecting rod nozzle, 33-copper sleeve, 34-copper sleeve oil groove, 35-diffusion groove, 36-radial oil hole, 50-piston pin, 51-first-stage piston, 52-second-stage piston, 53-oil return hole, 54-first-stage ring part, 55-first-stage guide part, 56-second-stage ring part, 57-second-stage guide part, 58-oil outlet, 61-first-stage cylinder, 62-second-stage cylinder, 63-first-stage cavity, 64-second-stage cavity, 65-fixed oil inlet. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the utility model belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0028] The overall structure of the utility model piston cylinder is shown in the three-dimensional diagram Figure 2As shown, it includes a cylinder cavity (the first-stage cylinder 61 and the second-stage cylinder 62 are shown in the figure) and a hollow piston arranged in the cylinder cavity and adapted to the cylinder cavity. The crankshaft 20 can be rotatably connected to the big end of the connecting rod 30, and there is a circumferential gap between the crankshaft 20 and the big end. The small end of the connecting rod 30 can be rotatably connected to the lower part of the piston. Through the up and down movement of the piston, the small end of the connecting rod 20 is driven to move up and down and rotate back and forth. Due to the limitation of the crankshaft 20, the big end of the connecting rod 30 can only push the crankshaft 20 to rotate in one direction around the rotation axis of the crankshaft 20. One end of the crankshaft 20 is preferably provided with an opening-oil inlet 21 connected to an external lubricating oil source with the rotation axis as the center. In this way, when the crankshaft 20 rotates, the oil inlet 21 only rotates in place around its center, so as to be conveniently connected to a fixed pipeline, and connected to an external lubricating oil source through a fixed pipeline or directly. Channels for conveying lubricating oil are provided inside the crankshaft 20 and the connecting rod 30. The lubricating oil is conveyed from the oil inlet 21 to the end of the small end of the connecting rod, and sprayed and atomized toward the bottom of the cavity inside the hollow piston. Preferably, a pressure pump is provided between the oil inlet 21 and the external lubricating oil source, for example, on a fixed pipeline, to pressurize the lubricating oil and then input it into the oil inlet 21, and maintain a certain pressure until it is sprayed out from the end of the small end and collides with the bottom under pressure to help atomization.

[0029] Figure 3 Shows Figure 2 In the cross-sectional view of the middle cylinder, a hollow crankshaft oil passage 22 is provided inside the crankshaft 20 along the substantially axial direction of the crankshaft 20. The crankshaft oil passage 22 extends along the length direction of the crankshaft 20, at least to the position where the big end of the connecting rod 30 is rotationally fixed to the crankshaft 20, and is connected to the annular gap between the big end and the crankshaft 20 through at least one crankshaft hole 23. In this way, the lubricating oil in the crankshaft oil passage 22 enters the gap through the crankshaft hole 23.

[0030] In a more preferred embodiment, if Figure 4 The lower end of the connecting rod 30 is shown in the figure, and the lower end is a concave section. The big end covers the crankshaft 20 through a bearing 24, and the crankshaft 20 rotates in the annular bearing 24. An annular bearing groove 25 is provided between the bearing 24 and the crankshaft 20, for example, a groove along the annular direction is provided in the middle of the bearing 24 in the figure. The crankshaft hole 23 connects the crankshaft oil passage 22 and the bearing groove 25, so that the lubricating oil in the crankshaft oil passage 22 is sent to the bearing groove 25 during the rotation of the crankshaft 20. One end of the connecting rod oil passage 31 opens to the bearing groove 25, so that the lubricating oil enters the connecting rod oil passage 31 from the bearing groove 25, and flows into the small end of the connecting rod 30 under the drive of pressure.

[0031] The opening of the connecting rod oil passage 31 at the small end is a connecting rod nozzle 32, which opens on the side of the small end facing the piston inner cavity. In this way, during the reciprocating translation of the piston, the connecting rod nozzle 32 swings back and forth with the small end, but always keeps aiming at the piston inner cavity, spraying lubricating oil into the piston inner cavity and generating a large amount of lubricating oil mist by colliding with the bottom of the piston inner cavity. Specifically, Figure 4 As shown in the upper end of the middle connecting rod 30, an annular copper sleeve 33 is fixed to the periphery of the small head, and the copper sleeve 33 is rotatably connected to the lower part of the piston. The copper sleeve 33 is provided with an annular copper sleeve oil groove 34, which connects the connecting rod oil passage 31 and the connecting rod nozzle 32, and sends the lubricating oil from the connecting rod oil passage 31 to the connecting rod nozzle 32, and sprays it to the bottom of the piston cavity. In a more preferred embodiment, considering the sliding friction between the copper sleeve 33 and the piston, at least one diffusion groove 35 is also opened on the sleeve 33 along the width direction, and the diffusion groove 35 is also connected to the copper sleeve oil groove 34, so that lubricating oil can be provided between the copper sleeve 33 and the lower part of the piston to lubricate the rotation between the two.

[0032] In a more preferred embodiment, if Figure 5 As shown, the piston pin 50 is a hollow tube with openings at both ends, and at least one transparent radial oil hole 36 is provided on the hollow tube. The radial oil hole 36 connects the copper sleeve oil groove 34 with the internal cavity of the hollow tube, and the lubricating oil is sent into the internal cavity of the hollow tube and into the cylinder through the openings at both ends, and also lubricates the sliding between the cylinder and the piston.

[0033] like Figure 6 As shown, at least one fixed oil inlet 65 can be provided on the side wall of the cylinder, which is also connected to an external lubricating oil source, for inputting lubricating oil into the cylinder to help lubricate the piston and the inner wall of the cylinder. When the cylinder is a differential cylinder, it includes two-stage cylinders that are connected to each other: a primary cylinder 61 with a larger diameter and a secondary cylinder 62 with a smaller diameter. Accordingly, the two-stage cylinders are provided with a primary piston 51 and a secondary piston 52 of corresponding sizes. In addition, the primary piston 51 reciprocates in the primary chamber 63, and the secondary piston 52 reciprocates in the secondary chamber 64 (see Figure 3 ) reciprocates in the first-stage cylinder 61. The fixed oil inlet 65 is arranged on the wall of the first-stage cylinder 61, and lubricating oil is input into the first-stage cavity 63 corresponding to the moving range of the first-stage piston 51, so as to help lubricate the first-stage piston 51 and the inner wall of the first-stage cavity 63. At the same time, a part of the lubricating oil may enter the second-stage cavity 64, and also help lubricate the second-stage piston 52 and the inner wall of the second-stage cavity 64.

[0034] The front view of the piston structure of the piston cylinder of the utility model is as follows: Figure 7As shown, the oil outlet hole 58 is provided at the connection between the ring part and the guide part. Especially for the step-type cylinder, the oil outlet hole 58 is provided at the junction of the primary ring part 54 and the primary guide part 55, and is preferably inclined toward the guide part, so as to ensure that a sufficient amount of lubricating oil mist falls on the guide part. The oil outlet hole 58 can also be provided between the secondary ring part 56 and the secondary guide part 57, but it is not very important. Because the lubricating oil mist diffused from the primary guide part 55 can also reach the secondary guide part.

[0035] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A new type of piston cylinder, characterized in that: It comprises at least one cylinder cavity and a hollow piston matched with the cylinder cavity, wherein the guide portion of the piston is rotatably connected to a small end of a connecting rod through a piston pin, and the large end of the connecting rod is rotatably connected to a crankshaft; The end of the crankshaft is provided with an oil inlet connected to an external lubricating oil source; the crankshaft is provided with a hollow crankshaft oil passage substantially axially inside, the crankshaft oil passage at least extending to the position of the big end, and communicating with the annular gap between the big end and the crankshaft through at least one crankshaft hole; A hollow connecting rod oil passage is provided inside the connecting rod from the large end to the small end, one end of which is connected to the gap; the other end of the connecting rod oil passage is a nozzle, which opens on the side of the small end facing the inner cavity of the piston; The inner cavity of the piston is provided with at least one oil outlet hole near the bottom away from the small head, which is used to output lubricating oil gas to the cylinder cavity.

2. The piston cylinder according to claim 1, characterized in that: The oil outlet hole opens at the ring portion of the piston and is used to output lubricating oil gas to at least the guide portion.

3. The piston cylinder according to claim 2, characterized in that: The oil outlet hole opens at the junction of the ring portion and the guide portion.

4. The piston cylinder according to claim 1, 2 or 3, characterized in that: The small head is sleeved with the piston pin through a copper sleeve, and a copper sleeve oil groove connecting the connecting rod oil passage and the connecting rod nozzle is opened on the side of the copper sleeve facing away from the piston pin along the approximate circumference of the piston pin.

5. The piston cylinder according to claim 4, characterized in that: The copper sleeve is provided with at least one diffusion groove along the width direction, and the diffusion groove is connected to the copper sleeve oil groove, and is used to provide lubricating oil between the copper sleeve and the piston to lubricate the rotation between the two.

6. The piston cylinder according to claim 4, characterized in that: The piston pin is a hollow tube with openings at both ends. The hollow tube is provided with at least one transparent radial oil hole for connecting the copper sleeve oil groove with the interior of the hollow tube.

7. The piston cylinder according to claim 1, 2 or 3, characterized in that: The big end covers the crankshaft through a bearing shell, an annular bearing shell groove is provided between the bearing shell and the crankshaft, the crankshaft hole communicates with the crankshaft oil passage and the bearing shell groove; the connecting rod oil passage opens into the bearing shell groove.

8. The piston cylinder according to claim 1, 2 or 3, characterized in that: It also includes a fixed oil inlet, which opens on the inner wall surface of the cylinder cavity and is used to input lubricating oil into the cylinder cavity.

9. The piston cylinder according to claim 8, characterized in that: The cylinder cavity comprises a primary cylinder with a larger inner diameter and a secondary cylinder with a smaller inner diameter. The inner cavities of the primary cylinder and the secondary cylinder are connected to each other, and the fixed oil inlet opens on the inner wall surface of the primary cylinder.

10. The piston cylinder according to claim 1, 2 or 3, characterized in that: It also includes a pressure pump connected to the lubricating oil source and the oil inlet.

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