JPH10196537A - Reciprocating piston compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the assemblage of the large end part and the small end part of a connecting rod, and reduce a rotational load due to the shaft torsion of a large end hole and a small end hole, in a reciprocating piston compressor used for a domestic refrigerator and so on. SOLUTION: The cylindrical locking part 22c of the rod part 22b of a small end part 22 is inserted in a cylindrical hole part 25b formed transverse to the large end hole 25a of a large end part 25, and also a locking pin 26 is inserted in a fixed hole 25c, thereby a connecting rod 21 is assembled while having a few degrees of torsional freedom around the shaft of the rod part 22b. Therefore, the workability and assemblage of the connecting rod 21 can be, of course, improved, and the shaft torsion of the large end hole 25a and the small end hole 22a are absorbed, so that the reduction of a rotational load and a lowering of efficiency can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relatively small reciprocating piston compressor used in a home refrigerator or the like.

[0002]

2. Description of the Related Art In recent years, reciprocating piston compressors have been variously improved with the aim of miniaturization and improvement of assemblability. On the other hand, the market demands higher efficiency and lower noise.

A conventional reciprocating piston compressor of this type is disclosed in Japanese Patent Application Laid-Open No. 4-164174 and Japanese Patent Publication No. 5-848.
No. 37 is disclosed.

In a conventional reciprocating piston compressor disclosed in Japanese Patent Publication No. 5-84837, a compressor body 1 is suspended from a housing 3 by a spring 2 as shown in FIG. The crankcase 4 integrally forms a mounting part 4a of the motor stator 5, a bearing part 4b for supporting the crankshaft 7 on which the motor rotor 6 is fitted, and a cylinder 4c for reciprocating the piston 8. Reference numeral 7a denotes an eccentric shaft of the crankshaft 7. Next, FIG.
As shown in (5), after the small end 11 of the connecting rod 10 to which the piston 8 is connected by the piston pin 9 is fitted into the cylinder 4c from the outer side, the valve plate 12 and the cylinder head 13 are attached. On the other hand, the eccentric shaft 7a of the crankshaft 7
The large end 14 of the connecting rod 10 is fitted into the connecting rod. afterwards,
The small end 11 and the large end 14 are connected by welding or the like.

As for the detailed structure of the connecting rod 10, as shown in FIG. 21, the small end 11 is formed integrally with a rod 11b having a rectangular cross section extending radially from the center of the small end hole 11a. Is formed in a pair of parallel surfaces 11d having a rectangular cross section, and the ends of the parallel surfaces are formed into a V-shape. One large end 14 is integrally formed with a protruding portion 14b in the radial direction from the center of the large end hole 14a. A fitting hole 14c for fitting the tip 11c of the rod 11b of the small end 11 is formed at the center of the protrusion 14b.

Therefore, by connecting the small end 11 and the large end 14 of the connecting rod 10 in this manner, the rotation of the crankshaft 7 is converted into the reciprocating motion of the piston 8 and the refrigerant sucked into the cylinder 4c is removed. Compress.

[0007]

However, in the above-mentioned conventional construction, the connecting rod 10 has a small end 11 and a large end 1.
4 is connected to the tip 11 of the rod 11b of the small end 11.
c and the fitting hole 14c of the large end 14 are fitted. However, the tip 11c of the rod 11b and the fitting hole 14c of the large end 14 need to have a very high precision surface finish. There was a disadvantage that it is.

Further, the shaft center of the large end hole 14a and the fitting hole 14
c or the axis of the small end hole 11a and the rod 11
If the parallel surface 11d of the tip 11c of b is slightly displaced in parallel, the axes of the large end hole 14a and the small end hole 11a of the connecting rod 10 are twisted, and the rotational load in the compression and suction processes accompanying the rotation of the crankshaft 7 increases. There is a possibility that the efficiency may be reduced.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and facilitates the machining of parts, reduces the rotational load generated by the torsion of the large-end hole shaft and the small-end hole shaft of the connecting rod, and achieves high efficiency. It is an object to provide a reciprocating piston compressor.

Further, in the above-mentioned conventional configuration, the piston 8,
The vibration generated at the piston pin 9 and the small end portion 11 is directly transmitted to the large end portion 14, and there is a possibility that abnormal noise is generated between the large end portion 14 and the eccentric shaft 7a.

Another object of the present invention is to solve such a conventional problem and to provide a reciprocating piston compressor which does not generate abnormal noise.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a small end for attaching a piston to a small end hole via a piston pin, and an eccentric shaft of a crankshaft is loosely fitted in a large end hole. A reciprocating piston compressor including a connecting rod configured to connect the large end to the cylindrical end, wherein the large end communicates with the cylindrical hole facing the center of the large end hole. The small end portion is integrally formed, and the small end portion is formed integrally with a rod portion extending and formed opposite to the center of the small end hole and a cylindrical locking portion at an end portion of the rod portion. The end of the rod portion is loosely fitted or lightly press-fitted into the hole portion, and the locking portion and the cylindrical hole portion are locked while having a slight degree of freedom in twisting around the axis of the rod portion by a locking pin. And the geometric axis arrangement of the small end hole and the large end hole of the connecting rod Because they are kept on the same plane, it is possible to eliminate the increase in the rotational load in the compression and suction processes due to the rotation of the crankshaft and the decrease in efficiency due to it, and to improve the workability of the parts, Assembly can be facilitated.

Further, a locking hole is formed in the cylindrical locking portion at the end of the rod portion, and the locking portion of the rod portion is loosely fitted or lightly press-fitted into the cylindrical hole portion at the large end, and is locked. The locking portion and the cylindrical hole portion are locked while giving a slight degree of freedom in twisting around the axis of the rod portion by a pin, and the geometrical axes of the small end hole and the large end hole of the connecting rod are provided. Are maintained on the same plane, so that assembling is easy and dimensional accuracy is easily ensured, and an increase in rotational load and a decrease in efficiency due to this can be prevented.

Further, a key groove is formed on the side surface of the cylindrical locking portion at the end of the rod portion, and the locking portion of the rod portion is loosely fitted or lightly pressed into the cylindrical hole at the large end. The locking pin is used to lock the locking portion and the cylindrical hole while giving a slight degree of freedom in twisting around the axis of the rod portion, and the geometric axes of the small end hole and the large end hole of the connecting rod are arranged. Are maintained on the same plane, the assembling is easy and the dimensional accuracy is easily obtained, and it is possible to prevent an increase in rotational load and a decrease in efficiency due to the increase.

Further, a circumferential groove is formed in the circumference of the cylindrical locking portion at the end of the rod portion, and the locking portion of the rod portion is loosely fitted or lightly press-fitted into the cylindrical hole at the large end. At the same time, by inserting a locking pin into the fixing hole and fitting it into the circumferential groove, the locking portion and the cylindrical hole are locked while having a slight degree of freedom in twisting around the axis of the rod portion. In addition, the arrangement of the geometric axis of the small end hole and the large end hole of the connecting rod is maintained on the same plane, so that assembly is easy and dimensional accuracy is easy to obtain, so that the rotational load increases and the efficiency decreases due to it. Can be prevented.

Further, a circumferential groove or a key groove is formed on the circumference of the cylindrical locking portion at the end of the rod portion, and the locking portion of the rod portion is loosely fitted into the cylindrical hole at the large end. Alternatively, while lightly press-fitting, inserting a forked pin into the fixing hole and fitting it into the circumferential groove or key groove, the locking portion and the cylindrical portion while having a slight degree of freedom in twisting around the axis of the rod portion. The small holes and the large ends of the connecting rods are locked on the same plane to keep the geometric axes of the connecting rods in the same plane. An increase and a decrease in efficiency due to the increase can be prevented.

Further, there is provided a connecting rod constituted by connecting a small end for attaching a piston to the small end hole via a piston pin, and a large end on which the eccentric shaft of the crankshaft is loosely fitted to the large end hole. A reciprocating piston compressor, wherein the large end is formed integrally with a cylindrical hole facing the center of the large end hole, a groove, and a fixing hole communicating with the groove. A rod portion extended to face the center of the end hole and a locking portion having a circumferential groove at an end portion of the rod portion are integrally formed, and the end portion of the rod portion is loosely fitted into the cylindrical hole portion. Alternatively, lightly press-fitting and inserting at least one ball into the locking space formed by the groove and the circumferential groove through the fixing hole, and inserting a locking pin into the fixing hole. While giving the degree of freedom of twist around the axis of the rod part Locked serial engaging portion and said cylindrical hole portion, since the arrangement of the geometric axis of said larger end hole and said small end hole of the connecting rod so as to maintain on the same plane,
It is easy to assemble and easy to obtain dimensional accuracy, and it is possible to prevent an increase in rotational load and a decrease in efficiency due to the increase.

Still further, a connecting rod constituted by connecting a small end for attaching a piston to the small end hole via a piston pin and a large end on which the eccentric shaft of the crankshaft is loosely fitted in the large end hole. The reciprocating piston compressor provided, wherein the large end is formed integrally with a cylindrical hole facing the center of the large end hole, and a bearing is locked in the cylindrical hole by press fitting or the like. The small end is free to twist around the axis of the rod by fixing the end of the rod by press-fitting or the like to the inner periphery of the bearing. The arrangement of the geometric axes of the small end hole and the large end hole of the connecting rod is maintained on the same plane while increasing the degree of accuracy, so that assembling is easy and dimensional accuracy is easily obtained, and the rotational load is increased. And the resulting reduction in efficiency It can be.

Still further, a connecting rod constituted by connecting a small end for attaching a piston to the small end hole via a piston pin and a large end on which the eccentric shaft of the crankshaft is loosely fitted to the large end hole. A reciprocating piston compressor comprising: a large end integrally formed with a cylindrical hole facing a center of the large end hole and a fixing hole communicating with the cylindrical hole; A loose fit or a light press fit between a rod portion extended to face the center of the small end hole, a cylindrical locking portion at the end of the rod portion, and a bottom surface of the cylindrical hole portion via a cushioning material. In addition, by inserting a locking pin into the fixing hole, the arrangement of the geometric axes of the small end hole and the large end hole of the connecting rod is maintained on the same plane. And abnormal noise can be reduced.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to solve the above-mentioned problems, the present invention provides a small end in which a piston is mounted via a piston pin in a small end hole, and an eccentric shaft of a crankshaft is loosely fitted in a large end hole. A reciprocating piston compressor provided with a connecting rod formed by connecting the large end to the cylindrical end, wherein the large end is a cylindrical hole facing the center of the large end hole and a fixed hole communicating with the cylindrical hole. The small end portion is formed integrally with a rod portion extending toward the center of the small end hole and a cylindrical locking portion at an end portion of the rod portion. The end portion of the rod portion is loosely fitted or lightly press-fitted, and the locking portion and the cylindrical hole portion are locked while having a slight degree of freedom in twisting around the axis of the rod portion by a locking pin, and Position the geometric axes of the small end hole and the large end hole in the same plane It is obtained so as to maintain.

Further, a locking hole is formed in the cylindrical locking portion at the end of the rod portion, and the locking portion is loosely fitted or lightly pressed into the cylindrical hole at the large end, and the locking pin is fixed. The rod and the cylindrical hole are locked while being inserted in communication with the hole and the locking hole so as to have a slight degree of freedom in twisting around the axis of the rod. The arrangement of the geometric axes of the end holes is maintained on the same plane.

Further, a key groove is formed on the side surface of the cylindrical locking portion at the end of the rod portion, and this locking portion is loosely fitted or lightly pressed into the cylindrical hole at the large end and inserted into the fixing hole. By fitting a locking pin into the key groove, the locking portion and the cylindrical hole are locked while allowing a slight degree of freedom in twisting around the axis of the rod portion, and a small end hole and a large end hole of a connecting rod are provided. Are maintained on the same plane.

Further, a circumferential groove is formed in the circumference of the cylindrical locking portion at the end of the rod portion, and this locking portion is loosely fitted or lightly pressed into the cylindrical hole at the large end and fixed. By fitting a locking pin into the circumferential groove through the hole, the locking portion and the cylindrical hole are locked with a small degree of freedom in twisting around the axis of the rod portion, and a small connecting rod is provided. The arrangement of the geometric axes of the end hole and the large end hole is maintained on the same plane.

Further, a circumferential groove or a key groove is formed on the circumference of the cylindrical locking portion at the end of the rod portion, and this locking portion is loosely fitted or lightly pressed into the cylindrical hole at the large end. At the same time, by inserting a bifurcated pin into the fixing hole and fitting it into the circumferential groove or the key groove, the locking portion and the cylindrical hole portion are provided with a slight degree of freedom in twisting around the axis of the rod portion. The connecting rod is maintained so that the geometric axes of the small end hole and the large end hole of the connecting rod are arranged on the same plane.

Further, according to the present invention, a small end for attaching a piston to the small end hole via a piston pin is connected to a large end in which an eccentric shaft of a crankshaft is loosely fitted in the large end hole. A reciprocating piston compressor provided with a connecting rod, wherein a large end is integrally formed with a cylindrical hole facing the center of the large end hole, a groove, and a fixing hole communicating with the groove, and a small end is formed of the small end. A rod portion extended at the center of the end hole and a locking portion having a circumferential groove at the end of the rod portion are integrally formed, and the locking portion is loosely fitted or lightly fitted into the cylindrical hole portion at the large end. By press-fitting, and inserting at least one or more balls into the locking space formed by the groove and the circumferential groove through the fixing hole, and inserting a locking pin into the fixing hole, The locking section and the locking section are provided with a degree of freedom of twist around the axis of the rod section. Locking the tubular hole, in which in order to maintain coplanar the arrangement of the geometric axis of the small end hole and big end hole of the connecting rod.

According to the present invention, the small end for attaching the piston to the small end hole via the piston pin is connected to the large end where the eccentric shaft of the crankshaft is loosely fitted in the large end hole. A reciprocating piston compressor having a connecting rod, wherein a large end is formed integrally with a cylindrical hole facing the center of the large end hole,
A bearing is locked into this cylindrical hole by press fitting, etc.
The small end is extended to face the center of the small end hole, and the end of this rod is fixed to the inner periphery of the bearing by press fitting or the like, so that the rod has a degree of freedom in twisting around the axis of the rod. However, the arrangement of the geometric axes of the small end hole and the large end hole of the connecting rod is maintained on the same plane.

Still further, the present invention is configured such that a small end for attaching a piston to a small end hole via a piston pin and a large end in which an eccentric shaft of a crankshaft is loosely fitted to a large end hole. Reciprocating piston compressor with a connecting rod,
A rod with a large end integrally formed with a cylindrical hole facing the center of the large end hole and a fixed hole communicating with the cylindrical hole, and a small end formed with an extension facing the center of the small end hole. A loose fit or a light press fit between the portion and the cylindrical locking portion at the end of the rod portion and the bottom surface of the cylindrical hole portion via a cushioning material, and inserting a locking pin into the fixing hole. Thus, the arrangement of the geometric axes of the small end hole and the large end hole of the connecting rod is maintained on the same plane.

As described above, when the large end of the crankshaft in which the eccentric shaft is loosely fitted is connected to the small end integrally formed with the rod by attaching the piston in the assembling process to make the connecting rod function. The connection between the large end and the small end, that is, the cylindrical hole at the large end and the locking portion at the end of the rod at the small end are cylindrical, so that the processing of each part is easy. In addition, the dimensional accuracy is easily obtained, and the assembly is simplified by simply inserting the locking pin. At the same time, there is a high degree of freedom in twisting around the axis of the rod. It absorbs and exerts a self-correction function so that the shafts always coincide with each other, thereby preventing an increase in the rotational load due to the torsion of the shafts.

Further, a circumferential groove is formed in the locking portion of the rod portion, and a groove and a fixing hole communicating with the groove are formed in the inner surface of the cylindrical hole at the large end facing the circumferential groove. The part and the cylindrical hole are fitted. Then, after inserting a ball made of metal or the like from the fixing hole, the locking pin is inserted into the fixing hole. Since the ball is loosely fitted in the locking space formed by the circumferential groove of the locking portion and the groove of the cylindrical hole, the rod does not come off from the cylindrical hole, and rotates around the axis of the rod. Has a torsional degree of rotation through the ball, so that even if there is slight axial runout between the small end hole and the large end hole, it is absorbed and the axes of the small end hole and the large end hole coincide. To self-correct
It is possible to prevent the rotational load from increasing due to the torsion of the shaft.

Further, since the bearing is fitted into the cylindrical hole at the large end and the locking portion of the rod is fitted to the inner ring of the bearing, the rod has a degree of freedom of rotation about the axis. It has a small axial runout between the small end hole and the large end hole, and self-corrects it so that the axes of the small end hole and the large end hole coincide with each other. Can be prevented and the efficiency can be prevented from lowering.

Further, a cushioning material is mounted between the bottom surface of the cylindrical hole at the large end and the front end surface of the locking portion of the rod, and the locking portion is loosely fitted into the cylindrical hole through the cushioning material. The large end and the small end are connected by inserting a locking pin into the hole, so the load vibration received by the rod is transmitted to the large end and the eccentric part via the cushioning material, so the vibration transmission is large. And the abnormal noise generated between the large end portion and the eccentric portion can be reduced.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. The same components as those in the related art are denoted by the same reference numerals, and detailed description is omitted.

(Embodiment 1) In FIG. 1, reference numeral 21 denotes a connecting rod, which is connected to a piston 24 via a piston pin 23 which is loosely fitted in a small end hole 22a of the small end 22, while a large end 25 is provided. The large end hole 25a is loosely fitted to the eccentric shaft 7a of the crankshaft 7.

FIG. 2 shows that the piston 24 incorporated in the small end portion 22 is inserted from the side of the cylinder 4c opposite the crankshaft 7,
The large end 25 shows an assembling method of inserting the eccentric shaft 7a of the crankshaft 7 from above vertically.

The large end 25 has a cylindrical hole 25b opposed to the center of the large end hole 25a and a fixing hole 25c penetrating therethrough.
Are formed integrally. The small end 22 has a small end hole 22a.
A rod portion 22b is formed integrally at right angles to the end portion, and an end portion thereof serves as a locking portion 22c.

3 and 4, after the locking portion 22c is inserted into the cylindrical hole 25b, the locking pin 26 is provided in the locking portion 22c of the small end portion 22 through the fixing hole 25c. 22d, and the small end 22 of the connecting rod 21 is inserted.
And the large end 25 are connected.

In the above configuration, the locking portion 22c which is a connecting portion between the cylindrical hole portion 25b of the large end portion 25 and the small end portion 22
Since each of them has a cylindrical shape, it is easy to machine and easily achieves high dimensional accuracy.

FIG. 5 is a view taken in the direction of arrow A shown in FIG. 4, in which a line C indicates the central axis of the large end hole 25a, and a line D and a line E
Indicates the center line of the small end hole 22a. Here, since the locking portion 22c, which is a connecting portion between the large end portion 25 and the small end portion 22, is cylindrical, before the locking pin 26 is inserted, a line D is formed around the axis of the rod portion 22b. Line E or Line E
However, after the locking pin 26 is inserted, the locking pin 26 is fixed so as to substantially coincide with the line C by the elastic force of the locking pin 26 itself.

Therefore, the compression of the reciprocating piston compressor,
In the suction process, the axes of the small end hole 22a and the large end hole 25a do not completely coincide with each other along the line C, and if the shaft is twisted, the small end hole 22a and the piston pin 23 or the large end hole 25a and the crank eccentric shaft 5a, the locking pin 26 moves slightly from the line D to the line E (as indicated by the line D in FIG. 5). Although the deflection of the line E is exaggerated, the deflection is actually about 100 μm with respect to the vertical axis of 100 mm) and the axes of the small end hole 22a and the large end hole 25a are absorbed. Since the self-correction is performed so that they coincide with each other and the operation is stabilized, it is possible to prevent an increase in rotational load due to the torsion of the shaft and a decrease in efficiency due to the increase.

(Embodiment 2) This embodiment is based on Embodiment 1. As shown in FIGS. 6 and 7, a small end hole is formed at the end of the locking portion 22c of the rod portion 22b of the small end 22. The locking rod 27 is formed to penetrate the locking hole 27 in parallel with the base rod 22a, and a fixing hole 28 communicating with the locking hole 27 is formed in the cylindrical hole 25b of the large end 25. Is assembled.

Therefore, in the assembling process, the small end portion 22 is formed.
When connecting the large end 25 with the locking hole 2 of the rod portion 22b,
Since the locking hole 27 of the large end 25 communicates with the locking pin 27, the locking pin 26 can be inserted from either side, so that the processing is simple and the dimensional accuracy can be easily obtained, and the assembling property is further improved. it can. In addition, it is possible to prevent an increase in rotational load due to the torsion of the shaft and a decrease in efficiency due to the increase.

(Embodiment 3) This embodiment is based on Embodiment 1. As shown in FIGS. 8 and 9, the small end hole 22a is formed in the side surface of the locking portion 22c of the rod portion 22b of the small end portion 22. A key hole 29 is formed in parallel with the fixing groove 30. On the other hand, a fixing hole 30 communicating with the key groove 29 is formed in the cylindrical hole 25b of the large end 25, and the locking pin 26 is inserted to connect the connecting rod 21 to the connecting rod 21.
Is assembled.

Therefore, in the assembling process, the small end 22
When connecting the large end 25 with the key groove 2 of the rod portion 22b,
9 and the fixing hole 30 of the large end 25 communicate with each other, so that they can be fitted from either side surface, and the assemblability is improved. In addition, the machining becomes easier because of the keyway machining. Of course, it is possible to prevent an increase in rotational load due to the torsion of the shaft and a decrease in efficiency due to the increase.

(Embodiment 4) This embodiment is based on Embodiment 1, and as shown in FIGS.
The locking portion 22c of the rod portion 22b has a circumferential groove 31 formed in the entire periphery thereof, while the fixing hole 32 penetrating the cylindrical hole portion 25b of the large end portion 25 so as to face the circumferential groove 31 is formed. Then, the connecting rod 21 is assembled by inserting the locking pin 26.

Therefore, in the assembling process, the small end 22
When connecting the large end 25 with the circumferential groove 3 of the rod portion 22b,
1 and the fixing hole 32 of the large end 25 are penetrated so that they can be locked to each other, so that the assemblability is improved. Moreover, since the locking portion 22c is cylindrical, the processing of the cross-sectional shape of the circumferential groove 31 such as an arc, a trapezoid, and a triangle is easy, and dimensional accuracy is easily secured. Further, the locking pin 26 is locked so as to press the circumferential groove 31, but since the circumferential groove 31 extends over the entire circumference, even a slight rotation of the rod portion 22b is possible, while the locking pin 26 itself has an elastic force. Therefore, these can absorb a slight shaft runout between the two cylindrical shafts of the small end hole 22a and the large end hole 25a, thereby preventing an increase in rotational load due to shaft torsion and a decrease in efficiency due to the rotation load.

(Embodiment 5) This embodiment is based on Embodiment 4, and as shown in FIGS.
A circumferential groove or a key groove 33 is formed in the entire circumference of the locking portion 22c of the rod portion 22b, while the cylindrical hole 2 of the large end 25 is formed.
The connecting rod 21 is assembled by penetrating two fixing holes 34 facing the circumferential groove or the key groove 33 in parallel with the large end hole 25a in the 5b and inserting the U-shaped bifurcated pin 35 into the fixing holes 34.

Therefore, in the assembling process, the small end portion 22 is formed.
When connecting the large end 25 with the circumferential groove or the key groove 33 of the rod portion 22b and the two fixing holes 34 of the large end 25 with the forked pin 35, the assemblability can be improved, of course. A more stable shaft runout adjustment function is exhibited, and it is possible to prevent an increase in the rotational load due to the torsion of the shaft and a decrease in efficiency due to the increase.

The bifurcated pin 35 is made of a material such as a spring material in addition to a steel material by appropriately setting the depth of the circumferential groove or the key groove 33 and the hole diameter of the fixing hole 34.
It is also possible to adjust the strength around the axis b.

(Embodiment 6) In FIGS. 14 and 15, the locking portion 22c of the small end portion 22 has a circumferential groove 36 on the entire circumference of the cylinder.
Has been removed. Inside the cylindrical hole portion 25b of the large end portion 25, a groove portion 37 is provided at a position facing the circumferential groove 36 when the locking portion 22c of the rod portion 22b is inserted,
The substantially cylindrical portion 38 is formed by the groove 37 and the circumferential groove 36.
Is formed. A fixing hole 39 communicating with the groove 37 is formed in the large end 25.

In the above configuration, the large end 2
No. 5 locking portion 22c of rod portion 22b in cylindrical hole portion 25b
Is inserted, at least one ball 40 is inserted from the fixing hole 39, and is inserted into the substantially cylindrical portion 38. The fixing hole 39 is sealed by the locking pin 41, and the connecting rod 21 is formed.

Therefore, the ball 40 has a locking function by being held in the substantially cylindrical portion 38 instead of the locking pin 26, and since the ball 40 is used, the degree of freedom of rotation of the rod portion 22b about the axis is further increased. The height of the small end hole 22a and the cylindrical axis of the large end hole 25a are absorbed by a slight axial runout and stabilized by self-correction so that the axes of the small end hole 22a and the large end hole 25a coincide. Therefore, it is possible to prevent an increase in rotational load due to the torsion of the shaft and a decrease in efficiency due to the increase.

(Embodiment 7) In FIGS. 16 and 17, the outer peripheral portion 42a of the bearing 42 is engaged with the cylindrical hole portion 25b of the large end portion 25 by press-fitting or the like, and is fitted to the inner peripheral portion 42b of the bearing 42. The connecting rod 21 is assembled by fixing the locking portion 22c of the rod portion 22b by a method such as press fitting.

As described above, the small end portion 22 of the connecting rod 21 connects the locking portion 22c of the rod portion 22b to the cylindrical hole portion 25b of the large end portion 25 via the bearing 42. The portion 22b has a high degree of freedom of rotation about the axis, and absorbs a slight axial vibration between the cylindrical axis of the small end hole 22a and the cylindrical axis of the large end hole 25a to reduce the small end hole 22a.
And the axis of the large end hole 25a is self-corrected so that the axis coincides with the axis of the large end hole 25a, thereby stabilizing the rotation.

The size and specifications of the bearing 42 can be appropriately selected depending on the type of the reciprocating piston compressor, and it is easy to assemble the bearing 42 into various models.

(Eighth Embodiment) In FIG.
A gap is provided between the end surface 22e of the rod portion 22b and the bottom surface 25d of the cylindrical hole portion 25b, the cushioning material 43 is attached to the gap, and the locking portion 22c of the rod portion 22b is connected to the cylindrical hole portion 2b.
After fitting into 5b, the connecting pin 19 is formed by inserting the locking pin 26 into the fixing hole 25c.

With the above structure, the load vibration applied to the rod portion 22b is transmitted to the large end portion 25 and the crank eccentric portion 7a via the cushioning member 43 while the compressor is driven. Vibration transmission is greatly reduced, and abnormal noise generated between the large end portion 25 and the eccentric portion 7a can be reduced.

The cushioning member 43 includes a plastic member, a rubber member, a composite member such as plastic and metal, and the like. The locking portion 22c of the rod portion 22b and the cylindrical hole portion 25 are provided.
An appropriate material can be set according to the condition between b and abnormal noise can be reduced.

[0058]

As is apparent from the above description, claim 1
According to the described invention, the large end of the connecting rod integrally forms the cylindrical hole facing the center of the large end hole and the fixing hole communicating with the cylindrical hole, while the small end is the small end. A rod extending in opposition to the center of the hole and a cylindrical locking portion are integrally formed at the end of the rod, and the cylindrical locking portion of the rod is loosely fitted into the cylindrical hole at the large end. Or, after lightly press-fitting, insert the locking pin into the fixing hole and lock the locking part of the rod part and the cylindrical hole part of the large end while securing a slight degree of freedom around the axis of the rod part, Since the arrangement of the geometric axes of the small end hole and the large end hole of the connecting rod is maintained on the same plane, it is possible to prevent an increase in the rotational load due to the torsion of the shaft and a decrease in efficiency due to the rotation load. In addition, since the locking part, which is the connecting part between the large end and the small end, is cylindrical, it is easy to process and the processing dimensions Degrees is readily released, manufacture, and easy to assemble.

According to the second aspect of the invention, after the cylindrical hole at the large end and the locking portion at the small end are fitted, the locking pin is fixed to the fixing hole of the cylindrical hole and the rod. Although the locking holes of the locking portions are communicated and inserted and fixed, the locking pins can be inserted from any direction of the fixing holes and the assembling becomes easier.

According to the third aspect of the present invention, a key groove is formed on the side surface of the cylindrical locking portion of the rod portion, and a fixing hole is formed in the cylindrical hole at the large end so as to face the key groove. Then, the small end and the large end are connected through this fixing hole,
The workability is further improved due to the keyway processing.

According to the fourth aspect of the present invention, a circumferential groove is formed on the circumference of the cylindrical locking portion of the rod portion, and is fixed to the cylindrical hole at the large end so as to face the circumferential groove. A hole is formed, and the small end and the large end are connected through this fixing hole.
The cylindrical locking portion allows concentric and more efficient machining.

According to the fifth aspect of the present invention, a circumferential groove or a key groove is formed on the circumference of the cylindrical locking portion of the rod portion.
A bifurcated pin is inserted into the fixed hole formed in the cylindrical hole at the large end so as to face the circumferential groove or the key groove and to sandwich them, and connect the small end and the large end. Therefore, it is possible to more stably prevent an increase in the rotational load caused by the torsion of the shaft around the axis of the rod portion and a decrease in efficiency due to the increase.

According to the sixth aspect of the present invention, a circumferential groove is formed in the circumference of the cylindrical locking portion of the rod portion, and the circumferential groove is formed in the cylindrical hole portion of the large end so as to face the circumferential groove. After the fixing hole is provided and the small end and the large end are connected, at least one ball is inserted from the fixing hole into the substantially cylindrical portion formed by the groove and the circumferential groove, and the locking pin is inserted into the fixing hole. Since the connecting rod is assembled in this manner, it is possible to further increase the degree of freedom in twisting the rod portion around the axis, and to prevent an increase in rotational load due to the torsion of the axis and a decrease in efficiency due to the increase.

According to the seventh aspect of the present invention, the outer peripheral portion of the bearing is locked into the cylindrical hole portion at the large end by press-fitting or the like, and the cylindrical locking portion of the rod portion is fixed to the inner peripheral portion of the bearing. By assembling the connecting rod by press-fitting or the like, it is possible to further increase the degree of freedom in twisting the rod portion around the axis, thereby preventing an increase in rotational load due to the torsion of the shaft and a reduction in efficiency due to the rotation.

According to the eighth aspect of the present invention, a gap is provided between the end surface of the rod portion and the bottom surface of the cylindrical hole at the large end, and a cushioning material is attached to the gap, and After the engaging portion is inserted into the cylindrical hole, a locking pin is inserted into the fixing hole at the large end to form a connecting rod. The vibration is transmitted to the large end and the crank eccentric part, greatly reducing the vibration transmission, preventing the rotational load and the efficiency from decreasing due to the torsion of the shaft, and preventing the vibration from being transmitted between the large end and the eccentric part. The generated abnormal noise can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a reciprocating piston compressor according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of a connecting rod and a piston before the compressor is assembled.

FIG. 3 is a plan view before the connecting rod is assembled.

FIG. 4 is a partial vertical sectional view when the connecting rod is assembled.

FIG. 5 is a state diagram of a connecting rod when the compressor is driven.

FIG. 6 is a plan view of a reciprocating piston compressor before assembling a connecting rod according to a second embodiment of the present invention.

FIG. 7 is a partial longitudinal sectional view of the connecting rod when it is assembled.

FIG. 8 is a plan view of a reciprocating piston compressor before assembling a connecting rod according to a third embodiment of the present invention.

FIG. 9 is a partial longitudinal sectional view when the connecting rod is assembled.

FIG. 10 is a plan view of a reciprocating piston compressor before assembling a connecting rod according to a fourth embodiment of the present invention.

FIG. 11 is a partial longitudinal sectional view when the connecting rod is assembled.

FIG. 12 is an exploded perspective view of a reciprocating piston compressor according to a fifth embodiment of the present invention before assembling a connecting rod.

FIG. 13 is a longitudinal sectional view of a main part when the connecting rod is assembled.

FIG. 14 is a plan view of a reciprocating piston compressor according to a sixth embodiment of the present invention when a connecting rod is assembled.

FIG. 15 is a longitudinal sectional view of a main part when the connecting rod is assembled.

FIG. 16 is a plan view of a reciprocating piston compressor before assembling a connecting rod according to a seventh embodiment of the present invention.

FIG. 17 is a longitudinal sectional view of a main part when the connecting rod is assembled.

FIG. 18 is a longitudinal sectional view of a main part of a reciprocating piston compressor according to an eighth embodiment of the present invention when a connecting rod is assembled.

FIG. 19 is a longitudinal sectional view of a conventional reciprocating piston compressor.

FIG. 20 is an exploded sectional view of the connecting rod and the piston before assembly.

FIG. 21 is an exploded plan view of the connecting rod large end and small end.

[Explanation of symbols]

 7 Crankshaft 7a Eccentric shaft 8,24 Piston 9,23 Piston pin 10,21 Connecting rod 11,22 Small end 11a, 22a Small end hole 14,25 Large end 14a, 25a Large end hole 22b Rod 22c Lock Part 22d, 27 Locking hole 22e End face 25b Cylindrical hole 25c, 28, 30, 32, 34, 39 Fixing hole 25d Cylindrical hole bottom 26, 41 Locking pin 29 Key groove 31, 36 Circumferential groove 33 Circumference Groove or keyway 35 Bifurcated pin 37 Groove 38 Substantially cylindrical part 40 Ball 42 Bearing 42a Outer peripheral part 42b Inner peripheral part 43 Buffer material

Claims (8)

[Claims] 1. A connecting rod comprising a small end for attaching a piston to a small end hole via a piston pin, and a large end in which an eccentric shaft of a crankshaft is loosely fitted to a large end hole. A reciprocating piston compressor, wherein the large end is formed integrally with a cylindrical hole facing the center of the large end hole and a fixed hole communicating with the cylindrical hole. Is formed integrally with a rod portion extended to face the center of the small end hole and a cylindrical locking portion at an end portion of the rod portion, and the end portion of the rod portion is loosely fitted into the cylindrical hole portion. Alternatively, after lightly press-fitting, the locking portion and the cylindrical hole portion are locked while giving a slight degree of freedom of twist around the axis of the rod portion by the locking pin through the fixing hole, and The arrangement of the geometric axes of the small end hole and the large end hole was maintained on the same plane. A reciprocating piston compressor characterized in that: 2. A locking hole is formed in a cylindrical locking portion at an end portion of a rod portion, and the locking portion of the rod portion is loosely fitted or lightly press-fitted into a cylindrical hole portion at a large end portion. The locking portion and the cylindrical hole portion are locked by communicating the fixing hole with the locking hole while giving a slight degree of freedom in twisting around the axis of the rod portion by a locking pin. 1
A reciprocating piston compressor as described. 3. A key groove is formed on the side surface of the cylindrical locking portion at the end of the rod portion, and the locking portion of the rod portion is loosely or lightly press-fitted into the cylindrical hole at the large end. The locking portion and the cylindrical hole portion are locked while a locking pin is fitted into the key groove in the fixing hole so as to have a slight degree of freedom in twisting around the axis of the rod portion. Item 2. A reciprocating piston compressor according to Item 1. 4. A circumferential groove is formed on the circumference of the cylindrical locking portion at the end of the rod portion, and the locking portion of the rod portion is loosely fitted or lightly press-fitted into the cylindrical hole at the large end. By inserting a locking pin into the fixing hole and fitting it into the circumferential groove,
2. The reciprocating piston compressor according to claim 1, wherein the locking portion and the cylindrical hole are locked while giving a slight degree of freedom in twisting about the axis of the rod portion. 5. A circumferential groove or a key groove is formed on the circumference of the cylindrical locking portion at the end of the rod portion, and the locking portion of the rod portion is loosely fitted in the cylindrical hole at the large end. Alternatively, while lightly press-fitting, inserting a forked pin into the fixing hole and fitting it into the circumferential groove or key groove, the locking portion and the cylindrical portion while having a slight degree of freedom in twisting around the axis of the rod portion. 2. The reciprocating piston compressor according to claim 1, wherein said hole is locked. 6. A connecting rod comprising a small end for attaching a piston to a small end hole via a piston pin, and a large end for loosely fitting an eccentric shaft of a crankshaft to a large end hole. A reciprocating piston compressor, wherein the large end is formed integrally with a cylindrical hole facing the center of the large end hole, a groove, and a fixing hole communicating with the groove. A rod portion extended to face the center of the end hole and a locking portion having a circumferential groove at an end portion of the rod portion are integrally formed, and the end portion of the rod portion is loosely fitted into the cylindrical hole portion. Alternatively, lightly press-fitting and inserting at least one ball into the locking space formed by the groove and the circumferential groove through the fixing hole, and inserting a locking pin into the fixing hole. To allow the torsion degree of freedom around the axis of the rod part. A reciprocating piston compressor, wherein a portion of the connecting rod and the cylindrical hole are locked, and the arrangement of the geometric axes of the small end hole and the large end hole of the connecting rod is kept on the same plane. 7. A connecting rod comprising a small end for attaching a piston to a small end hole via a piston pin, and a large end for loosely fitting an eccentric shaft of a crankshaft to a large end hole. A reciprocating piston compressor, wherein the large end is formed integrally with a cylindrical hole facing the center of the large end hole, and a bearing is locked into the cylindrical hole by press fitting or the like; An end portion is formed by extending a rod portion facing the center of the small end hole and an end portion of the rod portion is fixed to an inner peripheral portion of the bearing by press-fitting or the like, so that a degree of freedom in twisting around the axis of the rod portion is achieved. A reciprocating piston compressor wherein the geometric axes of the small end hole and the large end hole of the connecting rod are maintained on the same plane while holding the connecting rod. 8. A connecting rod comprising a small end for attaching a piston to a small end hole via a piston pin, and a large end for loosely fitting an eccentric shaft of a crankshaft to a large end hole. A reciprocating piston compressor, wherein the large end is formed integrally with a cylindrical hole facing the center of the large end hole and a fixing hole communicating with the cylindrical hole, and the small end is A loose fit or a light press fit is carried out between the rod portion extended and formed facing the center of the small end hole, the cylindrical locking portion at the end of the rod portion, and the bottom surface of the cylindrical hole portion via the cushioning material. A reciprocating piston compressor wherein a geometrical axis arrangement of the small end hole and the large end hole of the connecting rod is maintained on the same plane by inserting a locking pin into the fixing hole. .