Connecting rod structure for crankshaft of refrigerator compressor

Abstract

The utility model discloses a connecting rod structure, particularly discloses a connecting rod structure for a crankshaft of a refrigerator compressor, and belongs to the technical field of design and manufacturing of air conditioner parts. According to the connecting rod structure for the refrigerator compressor crankshaft, the self-strength can be remarkably improved, and the service life can be remarkably prolonged. The connecting rod structure comprises a large-hole connector and a small-hole connector, the connecting rod structure further comprises a frustum-shaped reinforced connecting rod body, the large-hole connector is fixedly connected with the large end of the frustum-shaped reinforced connecting rod body, and the small-hole connector is fixedly connected with the small end of the frustum-shaped reinforced connecting rod body; at least two bevel edges of the frustum-shaped reinforced connecting rod body in the length direction are one section of two isosceles three-angle bevel edges with the front end wall of the inner hole of the small-hole connector as the vertex and the diameter of the inner hole of the large-hole connector as the bottom edge respectively.

Description

Technical Field

[0001] This utility model relates to a connecting rod structure, and more particularly to a connecting rod structure for a refrigerator compressor crankshaft, belonging to the field of air conditioner component design and manufacturing technology. Background Technology

[0002] The connecting rod of a refrigerator compressor is a key component connecting the crankshaft and piston. Its performance directly affects the compressor's operating efficiency and lifespan. Therefore, minimizing wear and maximizing lifespan are crucial for the product. In current refrigerator compressors, the motor drives the crankshaft to rotate. The large end of the connecting rod engages with the short shaft of the crankshaft, transmitting force to the piston pin and then to the piston. However, in actual operation, the force exerted on the connecting rod by the short shaft of the crankshaft is often multi-directional, not entirely along the rod's direction. Therefore, the connecting rod's bending and torsional resistance is very important. Deformation of the connecting rod will exacerbate frictional wear at both ends.

[0003] Currently, most connecting rods are designed with parallel shafts, meaning that the projections of each segment of the shaft onto its cross-section form regular rectangles of equal shape and size. These existing traditional connecting rod structures have the following significant problems:

[0004] 1. Uneven force transmission: The unreasonable force structure design of traditional connecting rods can easily lead to stress concentration and reduce service life.

[0005] 2. Short fatigue life: Because the connecting rod is in contact with the crankshaft and piston pin, the surface of the moving pair is subjected to large forces, which reduces the life strength of the connecting rod and even the entire moving pair.

[0006] 3. Energy loss, obstructed power transmission path, and the transmitted force being used for useless work, reducing the compressor's working efficiency. Utility Model Content

[0007] The technical problem to be solved by this utility model is to provide a connecting rod structure for a refrigerator compressor crankshaft that can significantly improve its own strength and significantly extend its service life.

[0008] The technical solution adopted to solve the above-mentioned technical problems is: a connecting rod structure for a refrigerator compressor crankshaft, including a large-hole connector and a small-hole connector. The connecting rod structure also includes a frustum-shaped reinforcing connecting rod body. The large-hole connector is fixedly connected to the large end of the frustum-shaped reinforcing connecting rod body, and the small-hole connector is fixedly connected to the small end of the frustum-shaped reinforcing connecting rod body. At least the two inclined sides of the frustum-shaped reinforcing connecting rod body along its length are segments of two inclined sides of an isosceles triangular angle with the front wall of the inner hole of the small-hole connector as the vertex and the diameter of the inner hole of the large-hole connector as the base.

[0009] Furthermore, at least on the end where the frustum-shaped reinforcing connecting rod connects to the large-hole connector, an envelope ring extending circumferentially is provided, which increases the contact area between the frustum-shaped reinforcing connecting rod and the large-hole connector with the cooperation of the envelope ring.

[0010] The preferred embodiment of the above scheme is that an envelope ring is provided on both sides of the frustoconical reinforcing connecting rod body along the circumferential direction. The length of the envelope ring that wraps around the outer wall of the large hole connector along the circumferential direction is a 45° range on both sides with the axial center line of the connecting rod structure as the reference. The radial thickness of each envelope ring is not less than 2.25 mm.

[0011] Furthermore, an envelope ring extending circumferentially is also provided on the end of the frustum-shaped reinforcing connecting rod that connects to the small hole connector, and the frustum-shaped reinforcing connecting rod is set with a uniform thickness in the thickness direction.

[0012] The preferred embodiment of the above scheme is to provide a weight-reducing hole and a weight-reducing groove at the large end of the frustum-shaped reinforcing connecting rod.

[0013] Furthermore, the connecting rod structure also includes an oil film lubrication mechanism, which reduces the coefficient of friction between the large-hole connector and / or the small-hole connector and the corresponding crankshaft and / or piston pin under the cooperation of the oil film lubrication mechanism.

[0014] The preferred embodiment of the above scheme is that the oil film lubrication mechanism includes at least a lubrication groove disposed axially on the inner wall of the small hole connector, and the piston pin inserted into the inner hole of the small hole connector forms an oil film lubrication by the oil splashed out and stored in the lubrication groove for a short time.

[0015] Furthermore, one or two lubrication grooves are provided on the inner wall of the small hole connector along the circumferential direction. Each lubrication groove has a circumferential width of 1 mm and a radial depth of 0.3 mm.

[0016] A preferred embodiment of the above scheme is that the oil film lubrication mechanism further includes an oil supply groove provided on the crankshaft connection end, and the crankshaft inserted into the inner hole of the large-hole connector forms an oil film lubrication through the oil supplied in the oil supply groove at any time.

[0017] Furthermore, the length of the envelope ring set on the end where the frustum-shaped reinforcing connecting rod body connects to the small hole connector is also within a 45° range on both sides of the axial centerline of the connecting rod structure.

[0018] The beneficial effects of this utility model are as follows: The technical solution provided in this application sets the connecting rod body of the connecting large-hole connector and the small-hole connector into a frustum-shaped reinforced connecting rod body, and then fixes the large-hole connector to the large end of the frustum-shaped reinforced connecting rod body, and fixes the small-hole connector to the small end of the frustum-shaped reinforced connecting rod body; and when designing the frustum-shaped reinforced connecting rod body, at least the two hypotenuses along the length direction of the frustum-shaped reinforced connecting rod body are segments of the two hypotenuses of an isosceles triangle with the front wall of the inner hole of the small-hole connector as the vertex and the diameter of the inner hole of the large-hole connector as the base. In this way, since the various cross sections of the connecting rod body along the length direction gradually increase in the shape of isosceles triangles, it not only solves the problem of insufficient load-bearing capacity caused by using parallel rod bodies in the prior art, but also the problem of significantly shortened service life caused by uneven force during operation. The connecting rod with the above-mentioned structure of this application has the largest stress section at the high-frequency, high-input power end of the frustum-shaped reinforced connecting rod body that plays a load-bearing role, and then gradually decreases, thereby achieving the purpose of significantly improving its own strength and significantly extending its service life. Attached Figure Description

[0019] Figure 1 This is a three-dimensional structural diagram of the connecting rod structure used in the crankshaft of a refrigerator compressor according to this utility model;

[0020] Figure 2 This is a front view of the connecting rod structure of the refrigerator compressor crankshaft according to this utility model;

[0021] Figure 3 for Figure 2 Top view;

[0022] Figure 4 This is a three-dimensional structural diagram of the connecting rod structure of the refrigerator compressor crankshaft of this utility model in use.

[0023] The following are labeled in the diagram: 1. Large hole connector; 2. Small hole connector; 3. Frustum-shaped reinforced connecting rod; 4. Envelope ring; 5. Weight reduction hole; 6. Weight reduction groove; 7. Crankshaft; 8. Piston pin; 9. Lubrication groove; 10. Oil supply groove. Detailed Implementation

[0024] like Figure 1 , Figure 2 , Figure 3 as well as Figure 4The diagram illustrates a connecting rod structure for a refrigerator compressor crankshaft, provided by this invention, which significantly improves its strength and extends its service life. The connecting rod structure includes a large-hole connector 1 and a small-hole connector 2. It also includes a frustum-shaped reinforcing connecting rod body 3. The large-hole connector 1 is fixedly connected to the large end of the frustum-shaped reinforcing connecting rod body 3, and the small-hole connector 2 is fixedly connected to the small end of the frustum-shaped reinforcing connecting rod body 3. At least two inclined sides of the frustum-shaped reinforcing connecting rod body 3 along its length are segments of two isosceles triangular angles with the front wall of the inner hole of the small-hole connector as the apex and the diameter of the inner hole of the large-hole connector as the base. The technical solution provided in this application sets the connecting rod body of the large-hole connector and the small-hole connector into a frustum-shaped reinforced connecting rod body. The large-hole connector is then fixedly connected to the large end of the frustum-shaped reinforced connecting rod body, and the small-hole connector is fixedly connected to the small end of the frustum-shaped reinforced connecting rod body. Furthermore, in designing the frustum-shaped reinforced connecting rod body, at least two hypotenuses along its length are segments of two hypotenuses of an isosceles triangle with the front wall of the small-hole connector's inner hole as the vertex and the diameter of the large-hole connector's inner hole as the base. Thus, because the various cross sections of the connecting rod body gradually increase in size along its length, forming isosceles triangles, it not only solves the problems of insufficient load-bearing capacity caused by parallel rod bodies in existing technologies and the significant shortened service life due to uneven stress during operation, but also significantly improves the strength and extends the service life of the connecting rod with the above-mentioned structure. This is because the frustum-shaped reinforced connecting rod body, which plays a load-bearing role, has the largest stress section at the high-frequency, high-input power end, and then gradually decreases in size.

[0025] In order to maximize the strength of the connecting rod itself, especially the strength of the connection between the connecting rod and the large-hole connector 1, this application provides at least one circumferentially extending envelope ring 4 at the end where the frustum-shaped reinforcing connecting rod 3 connects to the large-hole connector 1. The frustum-shaped reinforcing connecting rod 3, with the cooperation of the envelope ring 4, increases its contact area with the large-hole connector 1. Preferably, envelope rings 4 are provided on both sides of the frustum-shaped reinforcing connecting rod 3 circumferentially. The length of the envelope ring 4 wrapping around the outer wall of the large-hole connector circumferentially is within a 45° range on both sides, with the axial centerline of the connecting rod structure as the reference. The radial thickness of each envelope ring 4 is not less than 2.25 mm. Simultaneously, an envelope ring 4 extending circumferentially is also provided at the end where the frustum-shaped reinforcing connecting rod 3 connects to the small-hole connector 2. The frustum-shaped reinforcing connecting rod 3 has a uniform thickness in the thickness direction. Similarly, the length of the envelope ring 4 provided on the end where the frustum-shaped reinforced connecting rod body 3 connects to the small hole connector 2 is also within a 45° range on both sides based on the axial centerline of the connecting rod structure. Furthermore, in order to improve the balance characteristics of the connecting rod during use, this application provides a weight-reducing hole 5 and a weight-reducing groove 6 at the large end of the frustum-shaped reinforced connecting rod body 3.

[0026] Correspondingly, lubrication is also an important factor in improving the connection's operating environment and extending its service life. Therefore, the connecting rod structure described in this application also includes an oil film lubrication mechanism. The friction coefficient between the large-hole connector 1 and / or the small-hole connector 2 and the corresponding crankshaft 7 and / or piston pin 8 is reduced through the cooperation of the oil film lubrication mechanism. Considering the specific circumstances of use, the oil film lubrication mechanism of this application at least includes a lubrication groove 9 axially disposed on the inner wall of the small-hole connector. The piston pin 8 inserted into the inner hole of the small-hole connector forms an oil film lubrication through the oil temporarily stored in the lubrication groove 9. Preferably, one or two lubrication grooves 9 are disposed circumferentially on the inner wall of the small-hole connector, each lubrication groove 9 having a circumferential width of 1 mm and a radial depth of 0.3 mm. Furthermore, the oil film lubrication mechanism described in this application also includes an oil supply groove 10 disposed on the crankshaft connection end. The crankshaft 7 inserted into the inner hole of the large-hole connector forms an oil film lubrication through the oil supplied from the oil supply groove 10 at any time.

[0027] In summary, the technical solution provided in this application also has the following advantages:

[0028] 1. Reliability life results: A sample was subjected to a 168-hour extreme working condition reliability life test. The results showed that the surface of the moving parts was free of any polishing wear marks upon opening the casing, and was as good as new. The surface of the connecting rod large hole was almost free of wear, and the reliability life was effectively improved.

[0029] 2. Stress and deformation distribution optimization: Analysis results using finite element simulation tools show that the maximum deformation of the connecting rod generally decreases by 10%-20%, and the stress at the big end of the connecting rod decreases by about 30%.

[0030] 3. Vibration suppression: The overall design of this structure makes the connecting rod's operating posture more stable, which improves the noise reduction effect. The noise can be reduced by about 0.6dB, and the vibration amplitude of the compressor in the X and Z directions is also reduced by 0.2mm.

[0031] Attached is a table comparing the changes in data after the improvements:

[0032]

[0033] Example 1

[0034] To reduce the problems of excessive vibration and insufficient strength of existing connecting rods, this application adopts an improved connecting rod structure:

[0035] like Figure 1 , Figure 2 and Figure 3As shown, the improved connecting rod differs from the general connecting rod structure in the change of the rod body. Previously, a straight rod body was used; now, the new connecting rod structure uses a flared, figure-eight shaped rod body, improving and strengthening the original connecting rod. The connecting rod includes a large end, a small end, and a rod body connecting the two, characterized by:

[0036] Gradient-flare rod body: The rod body expands in a flare shape from point C in the small end inner hole of the connecting rod towards points A and B in the large end inner hole of the connecting rod, with its two side contour lines being continuous and smooth curves. Point C is the intersection of the center line of the connecting rod body and the contour line of the distal end of the connecting rod small end inner hole. Points A and B are the upper and lower intersection points of the line passing through the center of the connecting rod large hole and perpendicular to the center line of the rod body with the contour line of the connecting rod large end inner hole.

[0037] Force transmission path optimization: An envelope ring surrounds the connecting rod's big end ring. The outer thickness of the envelope ring is approximately 2.25mm greater than the outer diameter of the connecting rod's big end (this can be adjusted proportionally based on the overall structural dimensions). The envelope ring has two straight lines parallel to the rod's centerline at its upper and lower ends. The line connecting the intersection of these lines and the outer edge of the envelope ring to the center of the connecting rod's big end forms a 45° angle with the rod's centerline. This envelope ring increases the contact area, effectively transferring the force from the connecting rod body to the big end, while also improving stability and reducing vibration. Furthermore, the curved outer contour of the envelope ring effectively avoids stress concentration issues.

[0038] Increased lubrication capacity: A lubrication groove, approximately 1mm wide and 0.3mm deep, is added to the inner bore of the connecting rod small end (this can be scaled up or down proportionally depending on the overall structural dimensions). Its function is to store some of the oil splashed out during crankshaft operation. During the oscillation of the connecting rod small end, the ability to form an oil film between the inner bore of the connecting rod small end and the piston pin (②) is enhanced. The stability of the oil film reduces the coefficient of friction between the two contact surfaces, thereby reducing wear between the rotating parts and enhancing the reliability and lifespan of the entire system.

[0039] Lightweight design to balance inertial forces: By creating a through hole in the connecting rod (the hole size needs to be scaled and calculated according to the different connecting rod sizes), material usage can be reduced, and the overall weight of the rod can be reduced (compared to not creating a hole), thereby reducing the inertial forces generated by reciprocating motion. The lightweight design, combined with optimized compressor balance weights, can also reduce the amplitude of operational vibration.

[0040] Structural principle:

[0041] The improvement mechanism primarily revolves around reducing stress, minimizing structural deformation, and enhancing lubrication strength, thereby reducing overall system wear and increasing reliability and lifespan. Given that the vector force transmitted from the connecting rod big end to the rod body in actual operation is not entirely parallel to the rod body direction, appropriately increasing the contact area of ​​the force ensures that the force from the connecting rod big end is transmitted along the rod body direction as much as possible, reducing the deformation of the rod body itself and improving its torsional and bending resistance. This significantly optimizes the deformation and stress of the connecting rod big end, reducing the deformation and wear amplitude between the connecting rod and the crankshaft short shaft, and lowering the risk of seizure between the connecting rod and the crankshaft short shaft due to wear. Increased connecting rod body strength effectively ensures the perpendicularity of the connecting rod big end and small end bores to the rod body direction during operation; simultaneously, enhanced lubrication capacity in the small end section and reduced rod body weight balance reciprocating inertial forces, greatly increasing the overall service life of the system.

[0042] The improved new connecting rod uses the same installation method as the traditional connecting rod. The position and size of the big end and small end holes of the connecting rod have not changed, nor has the center distance between the two holes. The material and process are powder metallurgy sintered parts. It can also be extended to other connecting rod materials. Only the rod body structure has changed, and it can be well connected to the original products.

[0043] During assembly, the big end of the connecting rod is fitted onto the short shaft of the crankshaft, the small end hole of the connecting rod is aligned with the piston through hole, and then the piston pin is inserted. During operation, the motor drives the crankshaft to rotate, causing the connecting rod and piston to perform reciprocating cyclic motion.

Claims

1. A connecting rod structure for a crankshaft of a refrigerator compressor, comprising a large hole connecting head (1) and a small hole connecting head (2), characterized in that: The connecting rod structure also includes a frustum-shaped reinforcing connecting rod body (3), a large hole connector (1) fixedly connected to the large end of the frustum-shaped reinforcing connecting rod body (3), and a small hole connector (2) fixedly connected to the small end of the frustum-shaped reinforcing connecting rod body (3); at least the two inclined sides of the frustum-shaped reinforcing connecting rod body (3) along its length direction are segments of two inclined sides of an isosceles triangular angle with the front wall of the inner hole of the small hole connector as the vertex and the diameter of the inner hole of the large hole connector as the base.

2. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 1, characterized in that: At least on the end of the frustum-shaped reinforcing connecting rod (3) that is connected to the large hole connector (1), an envelope ring (4) extending in the circumferential direction is provided. With the cooperation of the envelope ring (4), the frustum-shaped reinforcing connecting rod (3) increases its contact area with the large hole connector (1).

3. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 2, characterized in that: Envelope rings (4) are provided on both sides of the frustum-shaped reinforcing connecting rod (3) along the circumferential direction. The length of the envelope ring (4) wrapping the outer wall of the large hole connector along the circumferential direction is within a 45° range on both sides with the axial center line of the connecting rod structure as the reference. The radial thickness of each envelope ring (4) is not less than 2.25 mm.

4. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 2 or 3, characterized in that: An envelope ring (4) extending circumferentially is also provided on the end of the frustum-shaped reinforcing connecting rod (3) that is connected to the small hole connector (2), and the frustum-shaped reinforcing connecting rod (3) is provided with equal thickness in the thickness direction.

5. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 4, characterized in that: A weight-reducing hole (5) and a weight-reducing groove (6) are provided at the large end of the frustum-shaped reinforcing connecting rod (3).

6. The connecting rod structure for a refrigerator compressor crankshaft according to claim 5, characterized in that: The connecting rod structure also includes an oil film lubrication mechanism, which reduces the coefficient of friction between the large-hole connector (1) and / or the small-hole connector (2) and the corresponding crankshaft (7) and / or piston pin (8) under the cooperation of the oil film lubrication mechanism.

7. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 6, characterized in that: The oil film lubrication mechanism includes at least a lubrication groove (9) arranged axially on the inner wall of the small hole connector. The piston pin (8) inserted into the inner hole of the small hole connector forms an oil film lubrication by the short-term stored oil in the lubrication groove (9).

8. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 7, characterized in that: One or two lubrication grooves (9) are provided on the inner wall of the small hole connector along the circumferential direction. Each lubrication groove (9) has a circumferential width of 1 mm and a radial depth of 0.3 mm.

9. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 8, characterized in that: The oil film lubrication mechanism also includes an oil supply groove (10) provided on the crankshaft connection end. The crankshaft (7) inserted into the inner hole of the large hole connector forms an oil film lubrication through the oil supplied in the oil supply groove (10) at any time.

10. The connecting rod structure for a crankshaft of a refrigerator compressor according to claim 9, characterized in that: The length of the envelope ring (4) set on the end where the frustum-shaped reinforcing connecting rod (3) connects to the small hole connector (2) is also within a 45° range on both sides of the axial centerline of the connecting rod structure.

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