JP2013224593A - Hermetic type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly-efficient and highly-reliable hermetic type compressor that, in rolling of a ball of a thrust ball bearing, suppresses the generation of wear of raceways on rolling surfaces of an upper race and a lower race where the ball rolls and that prevents an increase in input.SOLUTION: A plurality of balls 168 are arranged in a holder 170 so that a distance of radius of gyration of the balls 168 is not same as the center of gyration of a shaft 140. A gap is provided between an inner diameter part 176 of the holder 170 and an outer periphery 178 of a main shaft 142. Rolling on the same raceway of each of the balls 168 is greatly reduced, whereby the efficiency is improved by an input reduction and the reliability is also improved by prevention of sliding wear.

Description

  The present invention relates to improving the reliability of a hermetic compressor (hereinafter referred to as a compressor).

  In recent years, with respect to hermetic compressors used in refrigeration apparatuses such as refrigerators and refrigerators, higher efficiency, lower noise, and higher reliability for reducing power consumption are desired.

  Conventionally, this type of hermetic compressor employs a thrust ball bearing for the purpose of improving efficiency and has a structure in which a shaft can freely rotate with respect to a main bearing (see, for example, Patent Document 1).

  The conventional compressor will be described below with reference to the drawings.

  4 is a longitudinal sectional view of a conventional hermetic compressor described in Patent Document 1, FIG. 5 is an enlarged view of a main part of FIG. 4, and FIG. 6 is a perspective view of a conventional thrust ball bearing.

  4 to 6, the hermetic container 2 accommodates an electric element 8 composed of a stator 4 and a rotor 6 and a compression element 10 that is rotationally driven by the electric element 8, and lubricates the bottom. Oil 12 is stored. The electric element 8 and the compression element 10 are assembled together to form a compression mechanism 14, and the compression mechanism 14 is elastically supported in the sealed container 2 by a plurality of coil springs 16.

  The compression element 10 includes a shaft 26 having an eccentric shaft portion 24 formed through a main shaft portion 20 and a flange portion 22, a cylinder block 32 forming a compression chamber 30, and a shaft block provided in the cylinder block 32 to support the shaft 26. Main bearing 34. Further, the compression element 10 includes a piston 36 that reciprocates in the compression chamber 30, and a connection mechanism 38 that connects the piston 36 and the eccentric shaft portion 24. The compression element 10 includes an upper race seating surface 42 provided at a lower portion 39 of the flange portion 22 of the shaft 26 and provided substantially at a right angle to the axis 40 a of the main shaft portion 20, and an upper portion of the main bearing 34. A thrust sliding portion 44 provided substantially at right angles to the shaft center 40b and supporting the load in the gravity direction of the shaft 26 and the rotor 6, and a thrust ball provided between the upper race seating surface 42 and the thrust sliding portion 44. A bearing 46 is further provided to form a reciprocating hermetic compressor.

  The shaft 26 supplies an oil supply mechanism 50 having one end communicating with the lubricating oil 12 stored in the sealed container 2 and a part of the lubricating oil 12 pumped up by the oil supply mechanism 50 to the main shaft portion 20 to the thrust sliding portion 44. And an oil supply groove 52.

  The electric element 8 includes a stator 4 fixed below the cylinder block 32 and a rotor 6 fixed to the main shaft portion 20 by shrink fitting.

  The thrust ball bearing 46 includes a plurality of balls 60, a holder portion 62 that holds the balls 60, and an upper race 64 and a lower race 66 that are respectively disposed above and below the ball 60. The upper race 64 is in contact with the upper race seating surface 42 of the collar portion 22, and the lower race 66 is in contact with the thrust sliding portion 44.

A plurality of balls 60 have raceways 74a and 74b on which the balls 60 roll as one ring on the rolling surfaces 72a and 72b on the side where the balls 60 roll while contacting the upper race 64 and the lower race 66, respectively. The holder part 62 is disposed on a circumference 76 having the same radius so as to remain.

  The operation of the hermetic compressor configured as described above will be described below.

  When the electric element 8 is energized from an external power source (not shown), the rotor 6 rotates and the shaft 26 rotates accordingly. Then, the motion of the eccentric shaft portion 24 is transmitted to the piston 36 via the coupling mechanism 38. As a result, the piston 36 reciprocates in the compression chamber 30, and the compression element 10 performs a predetermined compression operation.

  Thereby, the refrigerant gas is sucked into the compression chamber 30 from the cooling system (not shown), compressed, and then discharged to the cooling system again.

  At this time, the oil supply mechanism 50 of the shaft 26 draws up the lubricating oil 12 and lubricates each sliding portion (not shown). A part of the lubricating oil 12 is supplied from the oil supply groove 52 to the thrust sliding portion 44 to lubricate the thrust ball bearing 46.

  The weight of the shaft 26 and the rotor 6 is supported by a thrust ball bearing 46, and the ball 60 rolls between the upper race 64 and the lower race 66 when the shaft 26 rotates. As a result, the torque for rotating the shaft 26 is smaller than that of the thrust slide bearing. Therefore, the loss in the thrust bearing can be reduced and the input can be reduced, so that the compression operation can be performed with high efficiency.

JP 2005-127305 A

  However, in the above-described conventional configuration, all of the plurality of balls 60 roll only on one track 74a, 74b on the rolling surfaces 72a, 72b of the upper race 64 and the lower race 66, respectively. For this reason, when the operation time becomes longer, the number of sliding between the tracks 74a and 74b and the ball 60 may increase excessively, and uneven portions may be generated on the track, and the ball 60 repeatedly passes the tracks 74a and 74b. Repeated rolling has the problem of increased frictional resistance and increased input.

  The present invention solves the above-mentioned conventional problems, and suppresses the occurrence of wear on the raceway on the rolling surface of the upper race and the lower race where the ball rolls in rolling of the ball of the thrust ball bearing. The present invention provides a highly efficient hermetic compressor that suppresses the increase.

  In order to solve the above-described conventional problems, a compressor according to the present invention includes a thrust ball including a plurality of balls and a holder portion that holds the balls on a thrust sliding portion that supports a load in a gravity direction of a shaft and a rotor. A bearing is arranged, and the balls are arranged on the holder portion so that the rotation radius distances of the plurality of balls are not the same with respect to the rotation center of the shaft. In the rolling of the ball of the thrust ball bearing, the wear resistance between the upper race and the lower race where the ball rolls can be reduced, and the increase in input can be suppressed.

The compressor of the present invention can provide a highly efficient hermetic compressor that suppresses an increase in input.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. The principal part enlarged view of the hermetic compressor in Embodiment 1 of this invention The perspective view of the thrust ball bearing in Embodiment 1 of this invention Vertical section of a conventional hermetic compressor Enlarged view of main parts of a conventional hermetic compressor A perspective view of a thrust ball bearing of a conventional hermetic compressor

  According to a first aspect of the present invention, lubricating oil is stored in an airtight container, and an electric element including a stator and a rotor and a compression element driven by the electric element are accommodated, and the compression element is arranged in a vertical direction. A shaft in which the rotor is fixed to a main shaft portion that extends to the main shaft portion, a main bearing that supports the main shaft portion of the shaft, and a compression chamber that changes volume as the shaft rotates. A thrust ball bearing having a plurality of balls and a holder portion for holding the balls is disposed on a thrust sliding portion for supporting a load in the gravity direction of the rotor, and the plurality of the balls with respect to the rotation center of the shaft. The balls are arranged in the holder part so that the rotation radius distances thereof are not the same, and a gap is provided between the inner diameter part of the holder part and the outer peripheral part of the main shaft part.

  Thereby, since the rolling trajectories of the plurality of balls are not the same, each ball is less likely to roll on a specific trajectory, and the number of sliding times and the sliding distance between the balls and the trajectory are greatly reduced. As a result, it is possible to prevent the occurrence of unevenness on the track and prevent the ball from rolling easily, so that it is possible to provide a highly efficient hermetic compressor that suppresses an increase in input.

  According to a second aspect of the present invention, the ball is disposed in the holder so that the center of the inner diameter of the holder is not the same as the center of a circle formed by connecting a plurality of balls. In addition to the effects of the described invention, each ball is less likely to roll on a specific track, and the number of sliding and the sliding distance between the ball and the track are reduced. As a result, it is possible to prevent the raceway from being worn and prevent the ball from rolling easily, and thus it is possible to provide a highly efficient hermetic compressor that suppresses an increase in input.

According to a third aspect of the present invention, the plurality of balls are arranged on the same circumference, and the balls are arranged in the holder so that the center point on the circumference is not the same as the rotation center point of the shaft. Thus, in addition to the effects of the first and second aspects of the invention, each ball is less likely to roll on a specific track, and the number of sliding times and the sliding distance between the ball and the track are reduced.
As a result, it is possible to prevent the occurrence of unevenness in the track and prevent the ball from rolling easily, and thus it is possible to provide a highly efficient hermetic compressor that suppresses an increase in input.

  In the fourth aspect of the invention, one or more upper races are disposed between the ball and the thrust surface of the shaft, and since the sliding sound of the ball can be prevented from being transmitted directly to the shaft, it is highly efficient and low in performance. A noise hermetic compressor can be provided.

  In the fifth aspect of the invention, one or more lower races are disposed between the ball and the thrust surface of the shaft bearing, and since the sliding sound of the ball can be prevented from being transmitted to the shaft bearing, high efficiency and A low noise hermetic compressor can be provided.

  In the sixth aspect of the invention, the race surface where the race and the ball come into contact is a flat surface, each ball is less likely to roll on a specific track, and the number of slides and the slide distance between the ball and the track are reduced. By significantly reducing the occurrence of unevenness in the track and preventing the ball from rolling, it is possible to provide a highly efficient hermetic compressor that suppresses an increase in input.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is a perspective view of a thrust ball bearing according to the same embodiment.

  1 to 3, an airtight container 102 includes an electric element 108 including a stator 104 and a rotor 106 that is driven by a power supply device (not shown), and a compression that is rotationally driven by the electric element 108. Each of the elements 110 is stored, and lubricating oil 112 is stored at the bottom.

  Further, the electric element 108 and the compression element 110 are assembled together to form a compression mechanism 114. The compression mechanism 114 is elastically supported in the sealed container 102 by a plurality of coil springs 116.

  Next, the main configuration of the compression element 110 will be described.

  A cylinder block 120 constituting the compression element 110 is formed with a compression chamber 122 on a cylinder, and a piston 124 is reciprocally inserted into the compression chamber 122. A main bearing 126 is formed at the lower part of the cylinder block 120, and a thrust sliding part 130 provided at a substantially right angle to the axis 128 a of the main bearing 126 is formed at the upper part of the main bearing 126.

  The shaft 140 is formed with an eccentric shaft portion 146 via a main shaft portion 142 and a flange portion 144. The main shaft 142 is pivotally supported by the main bearing 126 in the vertical direction. The shaft 140 has an oil supply mechanism 150 having one end communicating with the lubricating oil 112 stored in the sealed container 102, and a part of the lubricating oil 112 pumped up by the oil supply mechanism 150 to the main shaft portion 142 to the thrust sliding portion 130. The eccentric shaft portion 146 and the piston 124 are connected by a connecting mechanism 154.

  The electric element 108 is fixed to the lower part of the cylinder block 120 with bolts (not shown) and includes a stator 104 having a winding 156 and a rotor 106 fixed to the main shaft 142 of the shaft 140 by shrink fitting or the like. It is composed of

  An upper race seating surface 164 is formed on the lower portion 162 of the collar portion 144 of the shaft 140 so as to be provided substantially at right angles to the axis 128 b of the main shaft portion 142. A thrust ball bearing 166 is disposed between the upper race seating surface 164 and the thrust sliding portion 130 in order to support the load in the gravity direction of the shaft 140 and the rotor 106.

  The thrust ball bearing 166 includes twelve balls 168, a resin holder 170 that holds the balls 168, and an upper race 172 and a lower race 174 that are respectively disposed above and below the ball 168. The race surface where the upper race 172, the lower race 174, and the ball contact is a flat surface.

  A gap is provided between the inner diameter portion 176 of the holder portion 170 and the outer peripheral portion 178 of the main shaft portion 142, the upper race 172 is in contact with the upper race seating surface 164, and the lower race 174 is in contact with the thrust sliding portion 130. Yes.

  The twelve balls 168 are arranged on the same circumference 200, and the center point 200 a of the circumference 200 has an eccentricity e so as not to be the same as the axis 128 b of the main shaft portion 142, and is arranged on the holder portion 170. It is installed. The ball 168a is disposed at the maximum radial position with respect to the axial center 128b, and 168b is disposed at the minimum radial position with respect to the axial center 128b.

  The ball 168a rolls on the track 172a and the track 174a while contacting the upper race 172 and the lower race 174, and the ball 168b rolls on the track 172b and the track 174b while contacting the upper race 172 and the lower race 174.

  The operation and action of the hermetic compressor configured as described above will be described below.

  When power is supplied to the electric element 108 from the inverter power supply device, the rotor 106 rotates and the shaft 140 rotates accordingly. Then, the rotational movement of the eccentric shaft portion 146 is transmitted to the piston 124 via the coupling mechanism 154, whereby the piston 124 reciprocates in the compression chamber 122, and the compression element 110 performs a predetermined compression operation.

  As a result, the refrigerant gas is sucked into the compression chamber 122 from the cooling system (not shown) and compressed, and then discharged to the cooling system again.

  At this time, the shaft 140 pumps up the lubricating oil 112 by the oil supply mechanism 150 of the main shaft portion 142 and lubricates each sliding portion (not shown) with the lubricating oil 112. A part of the lubricating oil 112 is supplied from the oil supply groove 152 to the thrust sliding portion 130 to lubricate the thrust ball bearing 166.

  The weight of the shaft 140 and the rotor 106 is supported by a thrust ball bearing 166, and the ball 168 rolls between the upper race 172 and the lower race 174 when the shaft 140 rotates. Therefore, the torque for rotating the shaft 140 is smaller than that of the thrust slide bearing. As a result, the loss in the thrust bearing can be reduced and the input can be reduced, so that high efficiency can be achieved.

  Next, sliding relating to the thrust ball bearing 166 will be described.

  When the shaft 140 rotates, each of the twelve balls 168 deviates from the shaft axis 128c by an eccentric amount e, and further, the distance between the inner diameter portion 176 of the holder portion 170 and the outer peripheral portion 178 of the main shaft portion 142 corresponds to the distance. Is freely rolled around the shaft axis 128c.

  By the way, the ball 168a in which the holder portion 170 is located at the maximum radial distance with respect to the shaft center 128c has a maximum clearance distance between the inner diameter portion 176 of the holder portion 170 and the outer peripheral portion 178 of the main shaft portion 142. Then, the track 172a and the track 174a of the ball 168a become a sliding portion of the maximum distance in the radial direction of the upper race 172 and the lower race 174.

  On the other hand, at this time, the track 172b and the track 174b of the ball 168b become the sliding portions of the minimum distance in the radial direction of the upper race 172 and the lower race 174.

  That is, for the upper race 172, each ball 168 rolls in a range surrounded by the tracks 172a and 172b. Similarly, for the lower race 174, each ball 168 rolls in a range surrounded by the tracks 174a and 174b.

Therefore, as in the conventional configuration shown in FIGS. 4 to 6, all the balls 60 roll on one track on the rolling surface 72 a of the upper race 64 and one track on the rolling surface 72 b of the lower race 66. Compared with the case of rolling only on 74b, under the same operating conditions, the balls 168 passing through the same track are greatly reduced.

  Further, since the sliding portion of the upper race 172 and the ball 168 of the lower race 174 is a flat surface, the ball 168 rolls more smoothly.

  From the above, sliding loss due to contact between the ball 168 and the upper race 172 and the lower race 174 can be reduced, and the ball 168 can be prevented from becoming difficult to roll. This realizes a highly efficient hermetic compressor in which an increase in input is suppressed.

  Further, by making the contact portion of the ball 168 the upper race 172 or the lower race 174, it is possible to reduce the transmission of the sliding sound generated by sliding to the cylinder block 120 and the shaft 140, and to reduce the generation of noise. Can do.

  As described above, the hermetic compressor according to the present invention significantly reduces the rolling of a specific track of a plurality of balls of a thrust ball bearing, and is highly efficient and highly reliable with suppressed increase in input. Since a hermetic compressor can be provided, it can be applied to uses such as a refrigeration apparatus such as a refrigerator-freezer, a vending machine, a freezer showcase, and a dehumidifier.

DESCRIPTION OF SYMBOLS 102 Sealing container 104 Stator 106 Rotor 108 Electric element 110 Compression element 112 Lubricating oil 122 Compression chamber 126 Main bearing 130 Thrust sliding part 140 Shaft 142 Main shaft part 166 Thrust ball bearings 168, 168a, 168b Ball 170 Holder part 172 Upper race 174 Lower race 176 Inner diameter 178 Outer periphery 200 Circumference 200a Center point

Claims (6)

Lubricating oil is stored in a sealed container, and an electric element having a stator and a rotor and a compression element driven by the electric element are accommodated, and the compression element is attached to a main shaft portion extending in a vertical direction. A shaft to which the rotor is fixed; a main bearing that supports the main shaft portion of the shaft; and a compression chamber that changes a volume as the shaft rotates, in a gravity direction of the shaft and the rotor. A thrust ball bearing having a plurality of balls and a holder portion for holding the balls is disposed on a thrust sliding portion that supports a load, and the rotation radius distance of the plurality of balls is the same with respect to the rotation center of the shaft. A hermetic compressor in which the ball is arranged in the holder portion so that a gap is not provided between the inner diameter portion of the holder portion and the outer peripheral portion of the main shaft portion. 2. The hermetic compressor according to claim 1, wherein the ball is arranged in the holder portion so that a center point of an inner diameter of the holder portion and a circle formed by connecting a plurality of balls are not the same. The plurality of balls are arranged on the same circumference, and the balls are arranged on the holder portion so that the center point on the circumference is not the same as the rotation center point of the shaft. Hermetic compressor. The hermetic compressor according to any one of claims 1 to 3, wherein one or more upper races are disposed between the ball and the thrust surface of the shaft. The hermetic compressor according to any one of claims 1 to 4, wherein at least one lower race is disposed between the ball and the thrust surface of the shaft bearing. 6. The hermetic compressor according to claim 4, wherein the race surface where the race and the ball contact is a flat surface.