Cylinder block of wobble plate type cylinder sleeve-free compressor

Abstract

The utility model provides a cylinder block of a wobble plate type cylinder sleeve-free compressor. The cylinder block comprises a plurality of cylinder holes, the piston assembly is arranged in the cylinder hole and suitable for reciprocating motion in the cylinder hole, and the piston assembly comprises a piston and a piston ring arranged on the piston; the piston ring is made of nylon or polytetrafluoroethylene materials. And a sliding fit clearance is formed between the inner wall of the cylinder hole and the peripheral surface of the piston ring. Through the core structure design of the sliding fit clearance between the piston ring made of a specific material and the cylinder hole, and in combination with the preferable structures of the piston, the connecting rod, the planetary plate and the driving and anti-rotation mechanism, the problems that the matching is too tight, the friction is increased and the like due to the fact that the thermal expansion characteristic of the nylon or polytetrafluoroethylene piston ring is not considered are effectively solved; and the operation efficiency and reliability of the compressor are improved.

Description

TECHNICAL FIELD

[0001] The utility model discloses a cylinder body of a swing plate type cylinderless compressor related to an air compressor. BACKGROUND

[0002] The swing plate type compressor has been widely applied in the automobile air conditioning system and other occasions requiring mobile or miniaturized refrigeration due to its compact structure, stable operation and high efficiency. Its core working principle usually relies on the rotation of the main shaft to drive the swash plate, and then drive the planetary plate (also known as the swing plate) to tilt and swing. The planetary plate is connected to the piston through multiple connecting rods, and the swinging motion of the planetary plate is converted into the reciprocating linear motion of the piston in the cylinder bore of the cylinder body, so as to realize the suction, compression and discharge of the refrigerant gas. The cylinder body, as the main component containing the piston assembly, planetary plate component and other core motion mechanisms, has a crucial influence on the overall performance, reliability and service life of the compressor due to the precision, structural design and matching relationship of the cylinder bore inside the cylinder body and the piston assembly.

[0003] In the existing swing plate type compressor technology, designers focus on the precise matching and adjustment between various moving parts to ensure stable and reliable operation of the compressor. For example, Chinese Patent No. CN221482088U discloses a swing plate type compressor with a spring. This prior art solution describes in detail an adjustment device for the anti-rotation mechanism inside the compressor. Its structure includes a fixed valve plate assembly, a fixed gear holding part, a fixed gear, a steel ball and a planetary plate, and the planetary plate drives the piston to move through the connecting rod. The key point is that one end of the fixed gear is connected with the steel ball, and the other end extends into the through groove in the fixed gear holding part, and a cavity is provided inside the other end to accommodate the spring. An adjustment screw passes through the valve plate assembly and contacts the end of the fixed gear containing the spring in the through groove. By rotating the adjustment screw, the pre-tightening force of the spring on the fixed gear can be applied or adjusted, and the axial position of the fixed gear is changed, the purpose is to adjust the engagement force or gap between the fixed gear, the steel ball and the corresponding toothed structure on the planetary plate. This scheme claims that through this adjustment, the jumping of the steel ball during movement due to the excessive gap of the anti-rotation mechanism can be avoided, thereby ensuring the stability of the swinging motion of the planetary plate. This design focuses on optimizing the matching state of the anti-rotation transmission chain at the rear end of the compressor through external adjustment means.

[0004] However, the inventors have found in their research that the prior art described above, while aiming to solve the stability problem of the anti-rotation mechanism, has its focus limited to the adjustment of the rear-end components of the compressor and has not fully considered the interaction between the cylinder bore and the piston assembly in the core working area of the compressor, especially the problems that may be caused when a specific material is used as the piston sealing element. Specifically, in modern swing plate type compressors, the volume of the piston ring will expand to a certain extent under the combined influence of the heat generated by the friction of the piston movement and the immersion in refrigeration oil during the operation of the compressor.

[0005] When the compressor operates at a high temperature and the piston ring expands, the actual gap between the outer circumferential surface of the piston ring and the inner wall of the cylinder bore will become too small, and even a negative gap (i.e., an interference fit) may occur. This tight structural fit between the piston ring and the inner wall of the cylinder bore caused by material expansion directly results in a sharp increase in the frictional resistance between the two. Practical new type content

[0006] The purpose of the present utility model is to provide a cylinder body of a swing plate type cylinder sleeveless compressor, and to solve the technical problem of a tight fit and increased friction between the piston ring and the cylinder bore caused by not fully considering the thermal expansion characteristics of a specific material piston ring in the background art.

[0007] To achieve the above-mentioned purpose, the technical solution provided by the present utility model comprises:

[0008] A cylinder body of a swing plate type cylinder sleeveless compressor, comprising a plurality of cylinder bores; and at least one piston assembly arranged in the cylinder bores and adapted to reciprocate therein, the piston assembly comprising a piston and a piston ring arranged on the piston; the piston ring is made of nylon or polytetrafluoroethylene material; a sliding fit gap is formed between the inner wall of the cylinder bore and the outer circumferential surface of the piston ring.

[0009] Preferably, the piston has an outer circumferential surface, the piston ring is arranged in an annular groove near the top of the outer circumferential surface of the piston; the piston has an outer protrusion beside the annular groove, and the outer protrusion is located on the outer circumferential surface.

[0010] Preferably, the piston assembly further comprises a connecting rod, the connecting rod is in the form of an elongated rod, and one end of the connecting rod is connected to the piston through a groove formed by the inner protrusion of the piston.

[0011] Preferably, the inner protrusion and the outer protrusion form a recess, and an end surface of the inner protrusion facing the recess extends along the axial direction of the piston.

[0012] Preferably, a planet disc is further included, the planet disc is a disc-like member, and a plurality of hinge points are circumferentially provided; the other end of the connecting rod is hingedly connected to one of the hinge points of the planet disc.

[0013] Preferably, a main shaft and a swash plate fixed on the main shaft are further included, the swash plate has an inclined end surface inclined to the axis of the main shaft; the planet disc is installed on the inclined end surface of the swash plate through a thrust bearing.

[0014] Preferably, a fixed gear, an oscillating gear and a plurality of steel balls arranged between the fixed gear and the oscillating gear are further included; the oscillating gear is connected to or is a part of the planet disc, and the fixed gear and the oscillating gear are engaged through the steel balls.

[0015] The technical effects of the utility model are embodied in:

[0016] By explicitly limiting the piston ring to adopt nylon or polytetrafluoroethylene, which has a specific thermal expansion coefficient, and ensuring that a sliding fit gap (i.e., a positive gap) is formed between the outer circumferential surface of the piston ring and the inner wall of the cylinder hole, the structure of the utility model fundamentally adapts to the physical properties of such materials expanding due to heat and oil immersion during operation. Even if the piston ring expands, the pre-set sliding fit gap can still ensure that the two do not form a tight or even interference contact, avoiding excessive friction caused by expansion, thereby reducing the operating power consumption of the compressor and improving related noise and carbon deposition problems.

[0017] Further, the piston ring is arranged in the annular groove near the top of the outer circumference of the piston, ensuring accurate positioning of the piston ring on the piston, so that it can play a sealing role at the correct position, thereby effectively utilizing the formed sliding fit gap; at the same time, the outer protruding structure arranged beside the annular groove, as part of the piston body, helps to improve the guidance of the piston in the cylinder hole or the distribution of the lubricating oil film, and assists in maintaining the stable movement and cooperation state between the piston ring and the cylinder hole.

[0018] The hinge connection between the groove formed by the inner protrusion of the piston and one end of the connecting rod provides a reliable and large force transmission connection method, ensuring that the piston assembly can be stably driven for reciprocating motion, which is the basis for realizing and maintaining the dynamic operation of the sliding fit state between the piston ring and the cylinder hole.

[0019] The recess formed by the inner protrusion and the top wall surface of the piston (where the outer protrusion is located) and the axial extension of the inner protrusion in a specific direction together constitute the specific internal and top structure of the piston head. This structure design affects the overall strength, mass distribution and stability of the connection with the connecting rod of the piston, optimizes the top space, is conducive to airflow or reduces the dead point volume, and further assists the smooth and efficient compression process.

[0020] The other end of the connecting rod is connected with the hinged point of the planetary disc in the circumferential direction, establishing the upstream part of the complete motion transmission chain from the planetary disc to the connecting rod and then to the piston. The planetary disc serves as the output end of the swing motion, which drives the piston reciprocating motion through the connecting rod, so that the piston ring can slide in the cylinder bore, thereby embodying the function of the sliding fit clearance.

[0021] The planetary disc is installed on the inclined end face of the swash plate and supported by bearings, constituting the core driving mechanism for converting the rotation motion of the main shaft into the swing motion of the planetary disc. This explains the source of the planetary disc motion, which is the most upstream power conversion structure for the compressor to realize the compression function, and provides the power basis for the reciprocating motion of the piston assembly.

[0022] The anti-rotation mechanism including the fixed gear, steel ball and swing gear restricts the rotation of the planetary disc through their meshing, ensuring that the planetary disc only performs pure swing. This stable swing motion directly ensures that the motion transmitted by the connecting rod to the piston is stable axial reciprocating linear motion, which is crucial for maintaining the long-term, reliable and uniform sliding fit clearance between the piston ring and the inner wall of the cylinder bore, avoiding abnormal wear or sealing failure caused by unstable piston posture.

[0023] In summary, the core structure design of the sliding fit clearance between the piston ring and the cylinder bore of a specific material, combined with the optimized structure of the piston, connecting rod, planetary disc and driving and anti-rotation mechanism, effectively solves the problems of tight fit and increased friction caused by not considering the thermal expansion characteristics of nylon or polytetrafluoroethylene piston rings, improving the operating efficiency and reliability of the compressor. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Fig. 1 is a structural schematic view of the cylinder body of the swing disc type cylinder sleeveless compressor according to an embodiment of the present utility model.

[0025] Figure 2 Fig. 2 is a structural schematic view of the piston assembly and cylinder bore according to another embodiment of the present utility model. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the present utility model clearer and more apparent, the present utility model will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present utility model and do not limit the present utility model.

[0027] Figure 1 Fig. 1 is a structural schematic view of the cylinder body of the swing disc type cylinder sleeveless compressor according to an embodiment of the present utility model. Figure 2 Fig. 2 is a structural schematic view of the piston assembly and cylinder bore according to another embodiment of the present utility model.

[0028] Referring to Figure 1 and Figure 2 , the utility model provides a kind of specific embodiment of the cylinder body of swing plate type sleeveless compressor (for conciseness, subsequent expression changes into cylinder body 6).The cylinder body 6 constitutes the main structure of compressor.

[0029] The cylinder body 6 includes multiple cylinder holes 28.These cylinder holes 28 are cylindrical inner cavities on the cylinder body 6, for accommodating piston assembly 4 and guiding its movement.

[0030] At least one piston assembly 4 is arranged in cylinder hole 28, and can reciprocate therein to compress refrigerant.The piston assembly 4 at least includes one piston 11 and one piston ring 12 mounted on piston 11.Piston ring 12 is the key component to realize dynamic sealing.

[0031] According to the core feature of the utility model, the piston ring 12 is made of nylon or polytetrafluoroethylene material.These two materials have specific physical properties, including volume expansion under certain temperature and oil immersion conditions.At the same time, the inner wall of cylinder hole 28 and the outer peripheral surface of the piston ring 12 made of nylon or polytetrafluoroethylene form a sliding fit gap in structure.The existence of this sliding fit gap means that even if the piston ring 12 expands due to working conditions, it can still maintain a proper positive clearance between the inner wall of cylinder hole 28, avoiding seizure or dramatic increase in friction due to excessive expansion.This is the basic structure of the utility model to solve the background technical problem.

[0032] Further, referring to Figure 2 , in order to ensure the correct positioning and function of piston ring 12, piston 11 has an outer peripheral surface, and piston ring 12 is accurately arranged in a specially designed annular groove near the top of the outer peripheral surface of piston 11.This arrangement ensures that the piston ring is in a stable working position during the reciprocating motion of the piston.In addition, beside the annular groove, piston 11 also integrally has an outer protrusion 111 on the outer peripheral surface of piston 11.The existence of this outer protrusion 111 changes the local geometry of the outer surface of the piston, which helps to improve the guiding, oil scraping effect of the piston or enhance the structural strength of the piston head, thereby assisting the piston ring 12 and cylinder hole 28 to form a stable and reliable sliding fit relationship.

[0033] Further, referring to Figure 1, the piston assembly 4 further comprises a connecting rod 10. The connecting rod 10 is generally in the form of an elongated rod, which serves to transmit motion and force. One end of the connecting rod 10 needs to be reliably connected to the piston 11. In the present embodiment, this connection is achieved by means of a special structure inside the piston 11, namely an inner protrusion 112. The inner protrusion 112 encloses a slot or space for accommodating the end of the connecting rod 10, which is placed in the slot and connected to the piston 11 by means of a pin or the like. This connection structure formed by the inner protrusion 112 is not only firm and reliable enough to withstand the huge forces during compression, but also allows the connecting rod 10 to swing relative to the piston 11 by a certain angle to meet the needs of motion conversion.

[0034] Further, with reference to Figure 2 In another embodiment, the internal structure of the piston 11 is further defined. The inner protrusion 112 mentioned above and the outer protrusion 111 located on the outer periphery of the piston top (or the wall surface of the piston top where it is located) jointly define and enclose a recess 113. This recess 113 is located in the central region of the top of the piston. At the same time, the side end surface of the inner protrusion 112 towards the recess 113 extends along the axial direction of the piston 11. This specific internal geometric design (the presence of the recess 113 and the shape and extension of the inner protrusion 112) not only optimizes the structure of the piston, reduces the weight of the piston to reduce the inertial force, or provides the necessary space for valve motion and gas flow, but also precisely defines the geometric characteristics of the connecting region with the connecting rod 10, affecting the connection strength and stability.

[0035] In addition, the inner protrusion 112 is a key structure connecting the piston top (which bears the combustion / compression pressure) and the piston pin / connecting rod. Its end surface extends along the axial direction, which means that a more solid and continuous axial support structure is formed below the piston top. The mass distribution and rigidity distribution of the internal structure of the piston will affect the stability of the posture of the piston during reciprocating motion in the cylinder bore, especially the inclination caused by lateral forces. By enhancing the rigidity of the piston top, this feature helps to maintain the precise shape of the ring groove, allowing the piston ring to float freely and fit the cylinder wall correctly even after expansion, achieving the designed sliding fit clearance.

[0036] Further, with reference to Figure 1 In order to drive the piston assembly 4 to move, the present embodiment further comprises a planet disc 9. The planet disc 9 is a disc-shaped member with multiple hinge points uniformly distributed around its circumference. The other end of the connecting rod 10 (i.e. the end away from the piston 11) is hingedly connected to one of the hinge points on the planet disc 9. Through this connection, the swinging motion of the planet disc 9 can be transmitted to the piston 11 through the connecting rod 10.

[0037] Further, referring to Figure 1 , the wobbling motion of the planetary disk 9 is generated by a higher level drive mechanism. The drive mechanism includes a main shaft that runs through the center of the compressor and a swash plate that is fixed on the main shaft. The swash plate is characterized by its end face that is inclined with respect to the axis of the main shaft. The planetary disk 9 is not directly fixed on the swash plate, but is mounted on the inclined end face of the swash plate through a rear thrust bearing. When the main shaft rotates, the fixed swash plate rotates with it, and its inclined end face forces the planetary disk 9 mounted on it to change its inclination regularly, i.e. to wobble. The rear thrust bearing ensures that the planetary disk 9 can smoothly wobble on the swash plate. This structure converts the rotation input of the main shaft into the wobbling output of the planetary disk.

[0038] Further, referring to Figure 1 , in order to ensure that the planetary disk 9 does not rotate around its own central axis (i.e. spin) during wobbling, so as to ensure that the piston 11 can stably reciprocate linearly along the axis of the cylinder bore 28, the present embodiment also includes an anti-spin mechanism. The mechanism is composed of a fixed gear 21, a wobble gear 23 and a steel ball 22 as a transmission medium. The steel ball 22 is arranged between the fixed gear 21 and the wobble gear 23. The fixed gear 21 is fixed relative to the cylinder block 6. The wobble gear 23 is connected with the planetary disk 9, or is itself a part of the planetary disk 9. Through the steel ball 22, the fixed gear 21 and the wobble gear 23 form a meshing relationship. When the planetary disk 9 attempts to spin, the wobble gear 23 will interfere with the fixed fixed gear 21 through the steel ball 22, thereby preventing the spin from occurring, ensuring that the planetary disk 9 only wobbles. This stable motion is crucial for maintaining uniform and reliable sliding fit clearance between the piston ring 12 and the cylinder bore 28.

[0039] In the present embodiment, referring to Figure 1 and Figure 2The cylinder body 6 of the swing plate type sleeveless compressor is a core bearing component of the compressor, has an integral structure, and internally comprises a swing plate box area for accommodating the movement of a planet plate 9, a swash plate, a connecting rod 10 and the like, and a plurality of (for example, 5) precisely machined cylindrical cylinder holes 28. The diameter of the cylinder hole 28 is for example Φ33 mm, and the inner diameter size has a specific manufacturing tolerance, for example +0.02 to +0.05 mm. The tolerance range is a key point of the present application relative to a design that only considers cold fit, and reserves space to accommodate the expansion of the piston ring 12. The cylinder body 6 is usually provided with flange interfaces at both ends, for connecting front and rear covers to form a closed compressor shell. The piston assembly 4 is accommodated in each cylinder hole 28. The piston assembly 4 is composed of a piston 11 and a piston ring 12. The piston 11 is generally cylindrical, has a recess 113 at the top, and is provided with a ring groove near the top for mounting the piston ring 12, and has an outer protrusion 111 beside the ring groove. The internal structure of the piston 11 is complex, and comprises an inner protrusion 112 for connecting the connecting rod 10, which clamps a spherical or spherical-like end of the connecting rod 10 to achieve hinged connection. The piston ring 12 is a ring-shaped part with a specific cross-sectional shape, made of polytetrafluoroethylene (or other nylon), inlaid in the ring groove of the piston 11, and has a smooth outer cylindrical surface in direct contact with the smooth inner wall of the cylinder hole 28 to form a dynamic sealing surface. The connecting rod 10 is an elongated rod connecting the piston 11 and the planet plate 9, and both ends are spherical or spherical-like hinged joints. The planet plate 9 is a disc-shaped plate with a hole in the center, mounted on the swash plate through a rear thrust bearing, and is connected to the connecting rod 10 through a plurality of evenly distributed hinged points in the circumferential direction. The swash plate is fixed on the rotating main shaft, and the end surface is inclined. The anti-rotation mechanism is composed of a fixed gear 21 (fixed on the cylinder body 6 or a related stationary part), a swing gear 23 (linked with the planet plate 9), and a steel ball 22 between the two, which restricts the planet plate 9 from rotating by the meshing of the gear and the steel ball. All these components work together to achieve the compression cycle of the refrigerant under the drive of the main shaft. Through the selection of the material of the piston ring 12 and the setting of the sliding fit gap between the cylinder hole 28 and the piston ring 12, the present application ensures that even if the piston ring 12 expands under actual operating conditions, the gap between the two is still appropriate, thereby significantly reducing friction loss and improving the overall performance and reliability of the compressor.

[0040] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A cylinder block of a sleeveless wobble-plate compressor, characterized by, Comprise: a plurality of cylinder bores (28); and at least one piston assembly (4) disposed in the cylinder bores (28) and adapted to reciprocate therein, the piston assembly (4) comprising a piston (11) and a piston ring (12) disposed on the piston (11); the piston ring (12) is made of nylon or polytetrafluoroethylene material; a sliding fit gap is formed between the inner wall of the cylinder bore (28) and the outer circumferential surface of the piston ring (12). The piston (11) has an outer circumferential surface, and the piston ring (12) is disposed in an annular groove near the top of the outer circumferential surface of the piston (11); the piston (11) has an outer protrusion (111) beside the annular groove, and the outer protrusion (111) is located on the outer circumferential surface.

2. The wobble-plate, sleeveless compressor cylinder block of claim 1 wherein, The piston assembly (4) further comprises a connecting rod (10), which is an elongated rod structure, one end of which is connected to the piston (11) through a slot formed by an inner protrusion (112) of the piston (11).

3. The wobble-plate, sleeveless compressor cylinder block of claim 2 wherein, 4. The swing plate type cylinder body of the sleeveless compressor according to claim 3, wherein the inner protrusion (112) and the outer protrusion (111) form a recess (113), and the side end surface of the inner protrusion (112) facing the recess (113) extends along the axial direction of the piston (11). Further comprising a planetary disc (9), which is a disc-shaped member with a plurality of hinge points circumferentially; the other end of the connecting rod (10) is connected to one of the hinge points of the planetary disc (9).

5. The wobble-plate, sleeveless compressor cylinder block of claim 4 wherein, Further comprising a main shaft and a swash plate fixed on the main shaft, the swash plate has an end surface inclined to the axis of the main shaft; the planetary disc (9) is installed on the inclined end surface of the swash plate through a thrust bearing.

6. The wobble-plate, sleeveless compressor cylinder block of claim 5 wherein, Further comprising a fixed gear (21), a swing gear (23) and a plurality of steel balls (22) disposed between the fixed gear (21) and the swing gear (23); the swing gear (23) is connected to the planetary disc (9) or is a part of the planetary disc (9), and the fixed gear (21) and the swing gear (23) are engaged through the steel balls (22).

7. The wobble-plate, sleeveless compressor cylinder block of claim 6 wherein, ​

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