KR20080059446A - Hermetic compressor - Google Patents

Abstract

A hermetic compressor includes a shaft having a connecting section formed between an eccentric shaft portion and a countershaft portion, the connecting section provided with an axial length sufficient for shifting a large end hole of a connecting rod to a position coaxial with the eccentric shaft portion. The shaft also has an extended surface of the eccentric shaft portion formed on the connecting section at one side opposite an eccentric axis thereof. This structure facilitates alignment of the center of axes of the eccentric shaft portion and the large end hole by simply sliding the extended surface of the shaft along a sliding surface of the large end hole, so as to ease insertion of the eccentric shaft portion into the large end hole, and prevent damages to the sliding surfaces of the eccentric shaft portion and the large end hole, thereby improving workability and productivity of assembling the shaft as well as reliability of the compressor.

Description

Hermetic compressor {HERMETIC COMPRESSOR}

The present invention relates to a hermetic compressor mainly used in a domestic refrigerator.

Japanese Patent Laid-Open No. 2004-137926 discloses a conventional hermetic compressor, which employs a shaft having a coaxial shaft and a main shaft portion interposed therebetween with an eccentric shaft portion interposed therebetween.

Hereinafter, the conventional hermetic compressor will be described with reference to the drawings.

15 is a longitudinal sectional view of a conventional hermetic compressor, FIG. 16 is an enlarged view of an essential part of a conventional shaft, and FIGS. 17 to 21 are enlarged cross-sectional views of an essential part of a circumference of a shaft for explaining the assembling steps of the conventional shaft in detail. .

As shown in FIGS. 15 to 21, the sealed container 1 is driven by a motor element 9 and a motor element 9 consisting of a stator 5 and a rotor 7 with windings 3. The compression element 11.

The compression element 11 is a cylinder having a compression chamber 21 substantially cylindrical in shape with a shaft 19 having a coaxial portion 15 and a main shaft portion 17 provided coaxially on the upper and lower sides of the eccentric shaft portion 13. A block 23 and a piston 25 reciprocating in the compression chamber 21 are included.

The compression element 11 is also provided with a connecting rod 27 having a small end hole 33 and a large end hole 37 which are integrally formed for connecting the piston 25 and the eccentric shaft portion 13, which are Is integrally assembled with the cylinder block 23. The compression element 11 has a subaxial bearing 29 for supporting the subaxial part 15 in an axial direction, and a cylinder block 23 made of aluminum-based material and fixed to the axial direction for supporting the main shaft part 17. The spindle bearing 31 is further provided. A screw or the like is used to fix the spindle bearing 31 to the cylinder block 23.

The hermetic compressor configured as described above operates as described below.

When the rotor 7 of the motor element 9 rotates the shaft 19, the rotational movement of the eccentric shaft portion 13 is transmitted to the piston 25 through the connecting rod 27, so that the piston 25 is compressed. The reciprocating motion is made in the chamber 21. As a result, the refrigerant gas is sucked into the compression chamber 21 from the cooling system (not shown in the figure), compressed, and discharged back to the cooling system.

Next, the shaft assembly step will be described.

As shown in FIG. 17, the piston 25 and the connecting rod 27 are first connected to the small end hole 33 by the piston pin 35 to assemble the piston con-rod assembly 43. do. Thereafter, the piston 25 is installed in the compression chamber 21 of the cylinder block 23. At this time, the cylinder block 23 is placed so that the compression chamber 21 faces downward. Since the piston cone rod assembly 43 is not fixed to the cylinder block 23, it slides down to the upper side 23a of the cylinder block 23 by its own weight.

Next, the minor shaft portion 15 of the shaft 19 is inserted into the cylinder block 23 from the opposite side of the minor shaft bearing 29. At this stage, the subshaft 15 is inserted into the large end hole 37 of the connecting rod 27 while lifting the piston cone rod assembly 43.

Then, as shown in FIG. 18, in order to insert the sub-shaft 15 into the sub-shaft 29 of the cylinder block 23, the shaft center of the sub-shaft 15 coincides with the axis of the sub-shaft bearing 29. The shaft 19 is moved upward while the piston cone rod assembly 43 is lifted to a height to be increased. Thereafter, the minor shaft portion 15 is pressed to be inserted into the minor shaft bearing 29.

As shown in FIGS. 19 to 21, the tip portion of the minor shaft portion 15 begins to enter the minor shaft bearing 29, and the minor shaft portion 15 completely passes through the large end hole 37. Thus, after the minor shaft portion 15 passes through the large end hole 37, the piston cone rod assembly 43 falls on the curved surface 41 of the connecting portion 39 by its own weight.

In order to fit the eccentric shaft portion 13 into the large end hole 37, the piston cone rod assembly 43 in the rest position on the curved surface 41 is again lifted up, and then the shaft of the eccentric shaft portion 13 has the large end hole. The eccentric shaft portion 13 is fitted into the large end hole 37 when it coincides with the axis of 37.

After the assembly of the shaft 19 is completed in the manner described above, the main shaft bearing 31 is fitted to the main shaft portion 17 of the shaft 19, and is fixed to the cylinder block 23 with a screw 45.

However, in the above-described conventional assembly step, the shaft of the eccentric shaft portion 13 when fitting the shaft 19 while lifting the piston cone rod assembly 43 upward from the curved surface 41 on which the large end hole 37 is placed. It does not easily coincide with the axis of this large end hole 37. Therefore, when the eccentric shaft portion 13 and the large end hole 37 are forcibly rubbed against each other, the sliding surface may be damaged and a considerable time is required for assembling, resulting in poor workability and low productivity.

The present invention addresses the problems of the prior art, and aims to provide a hermetic compressor with good workability of assembly and high productivity while preventing damage of the sliding surface during insertion of the eccentric shaft portion of the shaft into a large end hole. do.

The hermetic compressor of the present invention comprises a compression element enclosed in a hermetic container. The compression element includes a cylinder block forming a substantially cylindrical compression chamber, and a shaft integrally formed with a coaxial shaft and a main shaft portion interposed between the eccentric shaft portion and the eccentric shaft portion. The compression element further includes a sub-axial bearing formed in the cylinder block to support the sub-axis part in the axial direction, a main shaft bearing formed in the cylinder block to support the main axis in the axial direction, a piston for reciprocating motion in the compression chamber, and a piston and an eccentric shaft part. And a connecting rod provided with a large end hole fitted in the eccentric shaft portion. The connecting portion is formed between the eccentric shaft portion and the minor shaft portion of the shaft, and has an axial length sufficient to allow a large end hole to move to a position coaxial with the eccentric shaft portion, and an extension surface of the eccentric shaft portion is formed on the side of the connecting portion opposite to the eccentric shaft portion. do.

According to this structure, the eccentric shaft portion can be easily inserted into the large end hole by using the extension surface of the connecting portion after passing the minor shaft portion through the large end hole. Therefore, such a structure can prevent damage of the large end hole and the sliding surface of the eccentric shaft part of a shaft, and can improve workability and productivity in an assembly process.

1 is a longitudinal sectional view of a hermetic compressor according to the first embodiment of the present invention.

2 is an enlarged view of an essential part of the shaft according to this embodiment.

3 is an enlarged cross-sectional view of the main part around the shaft for explaining in detail the assembling step of the shaft according to this embodiment.

4 is another enlarged sectional view of the main part around the shaft for explaining the assembling step of the shaft according to this embodiment in detail.

Fig. 5 is another enlarged cross-sectional view of the main part around the shaft for explaining in detail the assembling step of the shaft according to this embodiment.

Fig. 6 is another enlarged sectional view of the main part around the shaft for explaining in detail the assembling step of the shaft according to this embodiment.

7 is a perspective view of an essential part of the shaft according to this embodiment.

8 is another enlarged sectional view of the main part around the shaft for explaining the assembling step of the shaft according to this embodiment in detail.

9 is a longitudinal sectional view of the hermetic compressor according to the second embodiment of the present invention.

10 is an enlarged view of an essential part of the shaft according to this embodiment.

Fig. 11 is an enlarged cross-sectional view of the main part around the shaft for explaining in detail the assembling step of the shaft according to this embodiment.

12 is another enlarged sectional view of the main part around the shaft for explaining in detail the assembling step of the shaft according to this embodiment.

13 is another enlarged sectional view of the main part around the shaft for explaining the assembling step of the shaft according to this embodiment in detail.

14 is another enlarged sectional view of the main part around the shaft for explaining the assembling step of the shaft according to this embodiment in detail.

15 is a longitudinal sectional view of a conventional hermetic compressor.

16 is an enlarged cross-sectional view of a main portion of a conventional shaft.

17 is an enlarged cross-sectional view of a main portion around a conventional shaft for explaining the assembling step of the shaft in detail.

18 is another enlarged cross-sectional view of a main portion around a conventional shaft for explaining the assembling step of the shaft in detail.

19 is another enlarged sectional view of the main part around the conventional shaft for explaining the assembling step of the shaft in detail.

20 is another enlarged cross-sectional view of the main part around the conventional shaft for explaining the assembling step of the shaft in detail.

21 is another enlarged sectional view of the main part around the conventional shaft for explaining the assembling step of the shaft in detail.

<Description of the symbols for the main parts of the drawings>

101, 102 airtight containers

109, 209 compression element

111, 211 eccentric shaft

113, 213 minor shaft

115, 215 spindle

117, 217 shaft

119, 219 compression chamber

121, 221 Cylinder Block

123, 223 minor shaft bearing

125, 225 spindle bearing

127, 227 piston

129, 229 connecting rod

131, 231 large end hole

133, 233 connection

135, 235 elongated surface

137, 237 end face

139, 239 Curved Geometry

141, 241 end face

143, 243 Curved Geometry

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)

1 is a longitudinal sectional view of a hermetic compressor according to a first embodiment of the present invention, FIG. 2 is an enlarged view of a main part of the shaft, and FIGS. 3 to 6 are main parts of the circumference of the shaft for explaining the assembly steps of the shaft in detail. An enlarged view of. Fig. 7 is a perspective view of the main part of the shaft, and Fig. 8 is another enlarged sectional view of the main part around the shaft for explaining the assembling step in detail.

1 to 8, a hermetic compressor according to this embodiment of the present invention will now be described.

1 to 8, the sealed container 101 is filled with a refrigerant (not shown), and also stores a refrigeration oil (not shown). In this example, the refrigerant is R600a, which is a hydrocarbon-based refrigerant, and the refrigeration oil is a mineral oil having compatibility with the refrigerant.

The motor element 103 includes a rotor 107 disposed inside the stator 105 at a predetermined distance from the stator 105 connected to an external power source (not shown).

The compression element 109 is made of a material such as a shaft 117 having an auxiliary shaft 113 and a main shaft 115 formed coaxially on the upper and lower sides of the eccentric shaft 111, a material such as an iron-based casting material, and is substantially cylindrical. A cylinder block 121 having a compression chamber 119 having a shape therein, and a piston 127 reciprocating in the compression chamber 119 shaft.

The compression element 109 also includes a connecting rod 129 having a small end hole 130 and a large end hole 131 formed therein for connecting the piston 127 and the eccentric shaft 111. The compression element 109 further comprises a minor shaft bearing 123 provided in the cylinder block 121 for axially supporting the minor shaft 113 of the shaft 117. The compression element 109 also includes a spindle bearing 125 made of aluminum-based material and fixed to the cylinder block 121 to support the main shaft portion 115 of the shaft 117 in the axial direction. A screw 132 is used to fix the spindle bearing 125 to the cylinder block 121.

The outer diameter of the minor shaft portion 113 of the shaft 117 is smaller than the outer diameter of the eccentric shaft portion 111. The connecting portion 133 is formed between the eccentric shaft portion 111 and the sub-shaft portion 113 of the shaft 117, the large end hole 131 of the connecting rod 129 inserted from the eccentric shaft portion 111 is the eccentric shaft portion ( Have a shaft length sufficient to move to a position coaxial with 111). The extended surface 135 of the eccentric shaft 111 is formed on the side of the connecting portion 133 facing the eccentric shaft. The extended surface 135 is processed simultaneously with the finishing processing of the eccentric shaft portion 111.

In other words, the extending surface 135 formed in the connecting portion 133 is coaxial with the eccentric shaft portion 111, and these have the same curvature with high precision. The eccentric shaft portion 111 is provided with an chamfered edge 136 on the end face 137 closer to the minor shaft portion 113.

Further, a curved shape 139 is formed between the eccentric shaft side of the connecting portion 133 and the end surface 137 of the eccentric shaft portion 111 of the shaft 117, which is the side of the minor shaft portion 113. A curved shape 143 is formed between one side of the connecting portion 133 facing the eccentric shaft side and the end surface 141 of the minor shaft portion 113 of the shaft 117 which is the eccentric shaft portion 111 side.

The rotor 105 is fitted to the main shaft 115 of the shaft 117. The stator 105 is fixed at a position below the cylinder block 121.

The hermetic compressor configured as described above operates in the manner described below.

The rotor 107 of the motor element 103 rotates the shaft 117. At this time, the rotational movement of the eccentric shaft 111 is transmitted to the piston 127 through the connecting rod 129. This reciprocates the piston 127 in the compression chamber 119. As a result, the refrigerant gas flows into the compression chamber 119 from the cooling system (not shown), is compressed, and is discharged again to the cooling system.

Next, the assembling step of the shaft 117 will be described.

As shown in FIG. 3, the piston cone rod assembly 147 is preassembled, and the piston 127 and the small end hole 130 in the connecting rod 129 are connected to the piston pin 145. After the piston 127 of the piston cone rod assembly 147 is installed in the compression chamber 119 of the cylinder block 121, the cylinder block 121 is placed so that the compression chamber 119 faces downward. Since the piston cone rod assembly 147 is not fixed, the piston cone rod assembly 147 slides down to the upper side 121a of the cylinder block 121 by its own weight.

Then, the minor shaft portion 113 of the shaft 117 is inserted into the cylinder block 121 from the opposite side of the minor shaft bearing 123. In this step, the piston cone rod assembly 147 is lifted up and the minor axis 113 is inserted into the large end hole 131 of the connecting rod 129.

Then, as shown in FIG. 4, in order to insert the sub-shaft 113 into the sub-shaft bearing 123 of the cylinder block 121, the axis of the sub-shaft 113 coincides with the axis of the sub-shaft bearing 123. The shaft 117 is moved upward while lifting the piston cone rod assembly 147 to the height. Thereafter, the minor shaft portion 113 is pushed in so as to be inserted into the minor shaft bearing 123.

As shown in FIG. 5, at the same time as the distal end portion of the minor shaft portion 113 begins to enter the minor shaft bearing 123, the minor shaft portion 113 completely passes through the large end hole 131. Thereafter, the piston cone rod assembly 147 falls by its own weight on the connecting portion 133 provided with the extension surface 135 having the same curvature as the inner wall of the large end hole 131 on the opposite side of the eccentric shaft.

In this example, as shown in FIG. 6, a curved portion is formed between one side of the connecting portion 133 facing the eccentric shaft and the end surface 141 of the minor shaft portion 113 that is the eccentric shaft portion 111 side of the minor shaft portion 113. Shape 143 is formed. Accordingly, the piston cone rod assembly 147 can slide along the curved shape 143 to the extended surface 135 while maintaining contact of the curved shape 143 with the inner sliding surface of the large end hole 131. . This structure can mitigate the impact that occurs when the large end hole 131 falls on the connecting portion 133, thereby preventing damage to the inner sliding surface of the large end hole 131 of the connecting rod 129.

6 and 7, a curved shape 139 is formed between the eccentric shaft side of the connecting portion 133 and the end surface 137 of the eccentric shaft portion 111. Therefore, it is possible to increase the circumferential size of the extension surface 135 on the side closer to the eccentric shaft 111. Thus, the possibility that the large end hole 131 is inclined with respect to the extension surface 135 can be reduced. Additionally, it is easy to match the shaft center before fitting the eccentric shaft portion 111, which greatly improves the workability of inserting the eccentric shaft portion 111 into the large end hole 131.

Subsequently, as shown in FIG. 8, the shaft center of the eccentric shaft portion 111 already coincides with the axis of the large end hole 131, so that the shaft 117 can be pushed further using the extension surface 135. have. As a result, the large end hole 131 slides on the extension surface 135 to be easily fitted to the eccentric shaft portion 111, and thus the sub shaft portion 113 to the minor shaft bearing 123 of the cylinder block 121. Complete the fitting process.

Although the combination of refrigerant and refrigeration oil described herein is an example using R600a and mineral oil, R290, a mixed refrigerant including this and other refrigerants, R134a, R152, R407C, R404A, R410, and refrigeration oil compatible with the refrigerant It can be done with any type of refrigerant selected.

As mentioned above, the hermetic compressor of this embodiment includes a compression element 109 enclosed within the hermetic container 101. The compression element 109 includes a cylinder block 121 that forms a substantially cylindrical compression chamber 119, and a minor shaft portion 113 formed coaxially with an eccentric shaft portion 111 and an eccentric shaft portion 111 interposed therebetween. And a shaft 117 in which the main shaft portion 115 is integrally formed. The compression element 109 is formed in the cylinder block 121 to support the sub shaft portion 113 in the axial direction, and the sub shaft bearing 123 and the cylinder block 121 to support the main shaft portion 115 in the axial direction. The main shaft bearing 125, the piston 127 reciprocating in the compression chamber 119, and a large end hole connecting the piston 127 and the eccentric shaft 111 and fitted to the eccentric shaft 111 ( It also includes a connecting rod 129 having a 131. The connecting portion 133 is formed between the eccentric shaft portion 111 and the sub shaft portion 113 of the shaft 117, and has an axis sufficient to allow the large end hole 131 to move to a position coaxial with the eccentric shaft portion 111. Has a length. The extended surface 135 of the eccentric shaft 111 is formed on the side of the connecting portion 133 facing the eccentric shaft. In the assembling step of fitting the eccentric shaft portion 111 of the shaft 117 to the large end hole 131 in the connecting rod 129, the axial center coincides with the eccentric shaft portion 111 and the large end hole 131 and the large end hole. In order to easily complete the insertion of the eccentric shaft portion 111 into the 131, the minor shaft portion 113 of the shaft 117 is inserted into the large end hole 131 of the connecting rod 129 and then the eccentric shaft portion ( It is only necessary to slide the sliding surface of the large end hole 131 over the extension surface of 111. Therefore, this structure can prevent the eccentric shaft portion 111 of the shaft 117 and the sliding surfaces of the large end hole 131 of the connecting rod 129 from being damaged. Thus, this structure can improve the workability and productivity of the assembly process, and thus can provide a hermetic compressor with high reliability and productivity.

As described above, in the hermetic compressor according to this embodiment, at the same time as the finishing processing of the eccentric shaft portion 111, an arc of curvature having the same extension surface 135 beside the eccentric shaft portion 111 as the inner wall of the large end hole 131. It is processed into a cross-sectional shape. Therefore, since the extension surface 135 and the eccentric shaft portion 111 are simultaneously processed in the shape of the same curvature as the inner wall of the large end hole 131, the axial center of the eccentric shaft portion 111 is the extension surface 135 connected with the eccentric shaft portion 111. It can be easily coincided with the center of gravity. As a result, the above structure can further improve the workability and productivity of the assembly of the shaft 117, and can provide a hermetic compressor with high reliability and productivity.

As also mentioned above, the hermetic compressor of this embodiment is provided with a curved shape 139 formed between the eccentric shaft side of the connecting portion 133 and the end face 137 of the eccentric shaft portion 111 on the side of the minor shaft 113. . Therefore, this structure is such that, while the shaft 117 is inserted into the large end hole 131 of the connecting rod 129, the connecting portion 133 on the eccentric shaft 111 side has an inner sliding surface of the large end hole 131. Can be prevented from being damaged. In addition, since the extension surface 135 has a larger circumferential size on the side closer to the eccentric shaft portion 111, the possibility that the large end hole 131 is inclined with respect to the extension surface 135 to facilitate the coincidence of the shaft centers. Can also be reduced. Therefore, the sliding surface of the large end hole 131 in the connecting rod 129 can be further prevented from being damaged. As a result, it is possible to improve the workability and productivity of the shaft assembly, and to provide a hermetic compressor with high reliability and productivity.

Additionally, as described above, in the hermetic compressor of this embodiment, the curved shape 143 formed between one side of the connecting portion 133 facing the eccentric shaft and the end surface 141 of the minor shaft 113 which is the eccentric shaft 111 side. This is provided. This structure has a large end hole 131 because the large end hole 131 slides along the curved shape 143 of the connection part 133 when it falls on the connection part 133 after passing through the sub-shaft part 113. ) Can be alleviated the impact when falling on the connecting portion (133). This can thus positively prevent damage to the eccentric shaft 111 of the shaft 117 and the sliding surfaces of the large end hole 131 of the connecting rod 129. Thus, this can further improve the workability and productivity of the shaft assembly, and can provide a hermetic compressor with much higher reliability and productivity.

(2nd Example)

9 is a longitudinal sectional view of the hermetic compressor according to the second embodiment of the present invention, FIG. 10 is an enlarged view of the main part of the shaft, and FIGS. 11 to 14 are the main parts of the circumference of the shaft for explaining the assembling step of the shaft in detail. It is a cross section.

9 to 14, a hermetic compressor according to this embodiment of the present invention will be described below.

9 to 14, the sealed container 201 is filled with a refrigerant (not shown), and also a refrigerator oil (not shown) is stored. In this example, the refrigerant is R600a, which is a hydrocarbon refrigerant, and the refrigeration oil is mineral oil compatible with this refrigerant.

The motor element 203 includes a rotor 207 disposed inside the stator 205 at predetermined intervals from the stator 205 connected to an external power source (not shown).

The compression element 209 is made of a material such as a shaft 217 having a sub-axial portion 213 and a main shaft portion 215 coaxially formed on the upper and lower sides of the eccentric shaft portion 211, an iron-based casting material, and formed therein. And a cylinder block 221 having a cylindrical compression chamber 219, and a piston 227 reciprocating in the compression chamber 219.

The compression element 209 also includes a connecting rod 229 provided with a small end hole 230 and a large end hole 231 for connecting the piston 227 and the eccentric shaft portion 211. The compression element 209 further includes a minor axis bearing 223 provided in the cylinder block 221 to axially support the minor axis 213 of the shaft 217. The compression element 209 also includes a spindle bearing 225 made of aluminum-based material and fixed to the cylinder block 221 to axially support the spindle 215 of the shaft 217. A screw 232 is used to fix the spindle bearing 225 to the cylinder block 221.

The outer diameter of the minor shaft portion 213 of the shaft 217 is the same dimension as the outer diameter of the eccentric shaft portion 211. The connecting portion 233 is formed between the eccentric shaft portion 211 and the sub shaft portion 213 of the shaft 217, and the large end hole 231 of the connecting rod 229 inserted from the eccentric shaft portion 211 is the eccentric shaft portion ( Have a shaft length sufficient to move to a position coaxial with 211). An extension surface 235 of the eccentric shaft portion 211 is formed on the side of the connection portion 233 opposite to the eccentric shaft. The extended surface 235 is processed simultaneously with the finishing processing of the eccentric shaft portion 211.

In other words, the extending surface 235 formed on the connecting portion 233 is coaxial with the eccentric shaft portion 211, and they have the same curvature with high precision. The eccentric shaft portion 211 is provided with an chamfered edge 236 on the end surface 237 closer to the minor shaft portion 213.

In addition, an extension surface 238 of the sub-axis portion 213 is formed on the extension area 233 on the eccentric shaft portion 211 side of the shaft 217, and the extension surface 238 finishes the sub-axis portion 213. It is processed simultaneously with processing.

In other words, the extension surface 238 formed on the extension region 233 is coaxial with the eccentric shaft portion 213, and they form the same curvature with high precision.

A curved shape 239 is also formed between the eccentric shaft side of the extension region 233 and the end surface 237 of the eccentric shaft portion 211, which is closer to the minor shaft portion 213 of the shaft 217. A curved shape 243 is formed between the extension region 233 facing the eccentric shaft and the end surface 241 of the minor shaft portion 213 of the shaft 217 on the side of the eccentric shaft portion 211.

The rotor 207 is fitted to the main shaft portion 215 of the shaft 217. The stator 205 is fitted to the position below the cylinder block 221.

The hermetic compressor configured as described above operates in the manner described below.

Rotor 207 of motor element 203 rotates shaft 217. At this time, the rotational movement of the eccentric shaft portion 211 is transmitted to the piston 227 through the connecting rod 229. This reciprocates the piston 227 in the compression chamber 219. As a result, the refrigerant gas flows into the compression chamber 219 from the cooling system (not shown), is compressed, and is discharged back to the cooling system.

Next, the assembling step of the shaft 217 will be described.

As shown in FIG. 11, the piston cone rod assembly 247 is preassembled, with the piston 227 and the small end hole 230 in the connecting rod 229 connected to the piston pin 245. After the piston 227 of the piston cone rod assembly 247 is installed in the compression chamber 219 of the cylinder block 221, the cylinder block 221 is placed so that the compression chamber 219 faces downward. The piston cone rod assembly 247 is forced to move to the upper side 221a of the cylinder block 221 by its own weight. In this case, however, the auxiliary device 248 is used to hold the connecting rod 229 near the large end hole 231 to keep the piston cone rod assembly 247 raised. In this way, the position of the connecting rod 229 is maintained at a height at which the axial center of the large end hole 231 coincides with the axial center of the minor shaft bearing 223.

Then, the minor shaft portion 213 of the shaft 217 is inserted into the cylinder block 221 from the opposite side of the minor shaft bearing 223. Accordingly, the minor shaft portion 213 is inserted into the large end hole 231 of the connecting rod 229. In this step, the outer diameter of the minor axis portion 213 is made to be the same dimension as the outer diameter of the eccentric shaft portion 211 to which the large end hole 231 is fitted, so that the minor axis portion 213 has a small gap and has a large end hole. 231, which prevents the minor shaft portion 213 and the large end hole 231 from hitting each other, thereby avoiding damage to their sliding surfaces during insertion. As a result, this structure can positively prevent damage to the minor shaft portion 213 of the shaft 217 and the sliding surfaces of the large end hole 231 of the connecting rod 229.

Then, as shown in FIG. 12, the shaft 217 is further pushed to insert the minor shaft portion 213 into the minor shaft bearing 223 while maintaining the position of the piston cone rod assembly 247 with the auxiliary device 248. Is put in. In this step, the extended surface 238 formed in the connecting portion 233 is the coaxial portion 213 because the extending surface 238 of the connecting portion 233 is coaxial with the minor axis portion 213 and has the same curvature with high accuracy. May continue to move on the sliding face of the large end hole 231 even after passing through the large end hole 231. This structure can stabilize the position of the shaft 217, which helps to facilitate the insertion process.

As shown in FIG. 13, when the shaft 217 is pushed in by sliding on the sliding surface of the large end hole 231, the large end hole 231 is the eccentric shaft side and the minor shaft part of the connection part 233. As shown in FIG. It comes into contact with the curved shape 239 formed between the end faces 237 of the eccentric shaft portion 211, which is closer to 213. The piston cone rod assembly 247 is then pushed down along the curved shape 239 by the assist device 248 while further pushing the shaft 217. This causes the connecting rod 229 to move steadily and gradually over the curved shape 239 to the end face 237 of the eccentric shaft portion 211. If the connecting rod 229 is further pushed down along the end face 237, the sliding face of the large end hole 231 may be in constant contact on the extension face 235.

In addition, as shown in FIG. 14, the curved shape 239 between the eccentric shaft side of the connecting portion 233 and the end surface 237 of the eccentric shaft portion 211 is located closer to the eccentric shaft portion 211. The circumferential size of the extension surface 235 can be increased. This reduces the likelihood that the large end hole 231 is tilted with respect to the extension surface 235. As a result, the matching of the axial centers before fitting the eccentric shaft portion 211 is further facilitated, which significantly improves the workability of inserting the eccentric shaft portion 211 into the large end hole 231.

Thereafter, the axis of the large end hole 231 is already coincident with the axis of the eccentric shaft portion 211 by using the extension surface 235, so that the large end hole 231 is opened when the shaft 217 is pushed further. It may slide on the extension surface 235. Accordingly, the large end hole 231 can be easily fitted to the eccentric shaft portion 211, thereby completing the process of fitting the minor shaft portion 213 to the minor shaft bearing 223 of the cylinder block 221.

Although the combination of refrigerant and refrigeration oil described herein is an example using R600a and mineral oil, the present invention is compatible with R290, a mixed refrigerant of this and other refrigerants, R134a, R152, R407C, R404A, R410, and the refrigerant. It may be implemented with any type of refrigerant selected from refrigeration oil.

As mentioned above, the hermetic compressor of this embodiment includes a subshaft portion 213 provided with an outer diameter equal to the outer diameter of the eccentric shaft portion 211, which is fitted into the large end hole 231. Therefore, this structure allows the eccentric shaft portion 211 of the shaft 217 to connect the large end hole 231 of the rod 229 since the sub shaft portion 213 can be fitted into the large end hole 231 with a small gap. ), It is possible to prevent damage to the eccentric shaft portion 211 of the shaft 217 and the sliding surfaces of the large end hole 231 of the connecting rod 229 in the fitting step. This structure also improves the workability and productivity of the assembly process and provides a hermetic compressor with high reliability and productivity.

The hermetic compressor of the present invention can be applied not only to refrigerators but also to various applications such as vending machine mill air conditioners.

Claims (5)

Having a compression element enclosed in a hermetically sealed container, The compression element is A cylinder block forming a substantially cylindrical compression chamber; A shaft having an integral eccentric shaft portion, a sub-shaft portion, and a main shaft portion, the shaft being formed coaxially with an eccentric shaft portion therebetween; A minor shaft bearing formed in the cylinder block and supporting the minor shaft portion in an axial direction; A main bearing formed in the cylinder block to support the main shaft in an axial direction; A piston reciprocating in the compression chamber; And  A connecting rod connecting the piston and the eccentric shaft portion with a large end hole fitted to the eccentric shaft portion, A connecting portion is formed between the eccentric shaft portion and the minor shaft portion of the shaft, and the connecting portion has a shaft length sufficient to allow the large end hole to move to a position coaxial with the eccentric shaft portion, The extended surface of the said eccentric shaft part is formed in the side opposite to the eccentric aix of the said connection part. The method according to claim 1, The extended surface of the said eccentric shaft part is processed into the circular cross section which has the same curvature as the curvature of the inner wall of the said big end hole simultaneously with the finishing process of the said eccentric shaft part. The method according to claim 1 or 2, A hermetic compressor, in which a curved shape is formed between an eccentric shaft side of the connecting portion and an end surface that is the minor shaft portion side of the eccentric shaft portion. The method according to claim 1 or 2, A hermetic compressor, in which a curved shape is formed between one side of the connection portion facing the eccentric shaft side and an end face that is the side of the eccentric shaft portion of the minor shaft portion. The method according to claim 1 or 2, The said minor shaft part has the outer diameter of the same magnitude | size as the outer diameter of the said eccentric shaft part for fitting to the said big end hole.

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