JP2014025425A - Hermetic type compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hermetic type compressor including a main bearing extension part formed on an upper part of a thrust surface of a cylinder block and a thrust ball bearing arranged on the upper surface of the thrust surface and an outer peripheral part of the main bearing extension part, capable of preventing a contact state between a ball and a lower race from becoming unstable and capable of improving reliability.SOLUTION: By forming an oil reservoir groove 184 among a thrust surface 116, an oil fence 180 and a main bearing extension part 157 and forming an oil discharge mechanism 182 on the bottom of the oil reservoir groove 184, sufficient lubricant 103 is supplied to a lower race 169, and by stabilizing a contact state between a ball 165 and the lower race 169 and preventing damage of the ball 165 and the lower race 169 by removing metallic powder from the lubricant 103 through the oil discharge mechanism 182, reliability can be improved.

Description

  The present invention relates to a hermetic compressor used mainly in a refrigeration cycle such as an electric refrigerator-freezer.

  In recent years, for hermetic compressors used in refrigeration equipment such as refrigerators and refrigerators, the main bearing upper end is extended and a main bearing extension is provided from the viewpoint of high efficiency to reduce power consumption, and the outer periphery is thrust. Some have a ball bearing (see, for example, Patent Document 1).

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

  4 is a vertical cross-sectional view of a conventional hermetic compressor described in Patent Document 1, FIG. 5 is an enlarged view of the main part of FIG. 4, and FIG. 6 is a lubricating oil near the main bearing extension. It is a schematic diagram which shows the flow.

  4 to FIG. 5, the lubricating oil 3 is stored at the bottom in the sealed container 1, and the compressor body 5 is elastically supported in the sealed container 1 by the suspension spring 7. The sealed container 1 is filled with R600a (isobutane), which is a refrigerant with a low global warming potential.

  The compressor body 5 includes an electric element 11 including a stator 13 and a rotor 15, and a compression element 17 disposed above the electric element 11. The hermetic container 1 includes a terminal 26 and is connected to the electric element 11 by a lead wire (not shown).

  The shaft 19 constituting the compression element 17 has a main shaft portion 23 and an eccentric shaft portion 25 formed eccentric to the main shaft portion 23. The main shaft portion 23 includes an oil supply mechanism 28 formed of a spiral groove provided on the surface. The cylinder block 29 has a substantially cylindrical cylinder 37 and a main bearing 31 that supports the main shaft portion 23. The main bearing 31 includes a thrust surface 16 that is a flat portion perpendicular to the shaft center, and a main bearing extension 57 that extends further upward than the thrust surface 16 and has an inner surface facing the main shaft portion 23.

  A thrust ball is stacked on the upper surface of the thrust surface 16 so as to surround the main bearing extension 57 in a state where the support member 71, the lower race 69, the ball bearing 63 composed of the holder 67 and the ball 65, and the upper race 61 are in contact with each other. A bearing 59 is arranged.

  The upper race 61 and the lower race 69 are annular and metal flat plates whose upper and lower surfaces are parallel.

  The holder 67 is formed of a resin material such as polyamide, has an annular shape, and has a plurality of holes in which the balls 65 are movably accommodated.

  The thrust ball bearing 59 is a bearing in which the ball 65 rolls in a point contact state with the upper race 61 and the lower race 69, and can rotate while supporting a vertical load such as the weight of the shaft 19 and the rotor 13 or the like. .

  The piston 33 is reciprocally inserted into the cylinder 37. In addition, the connecting means 43 connects the eccentric shaft portion 25 and the piston 33 by fitting the holes provided at both ends into the piston pin 35 and the eccentric shaft portion 25 attached to the piston 33, respectively.

  The cylinder 37 and the piston 33 form a compression chamber 41 together with a valve plate 39 attached to the opening end surface of the cylinder 37. Further, the cylinder head 53 is fixed so as to cover the valve plate 39 and cover it.

  The suction muffler 55 is molded of a resin such as PBT, forms a sound deadening space 56 inside, and is sandwiched between the cylinder head 53 and the valve plate 39.

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

  When the electric element 11 is energized, the rotor 15 rotates together with the shaft 19 by the magnetic field generated in the stator 13. Further, the upper race 61 also rotates with the shaft 19. As the main shaft portion 23 rotates, the eccentric shaft portion 25 rotates eccentrically, and this eccentric motion is converted into a reciprocating motion via the connecting means 43, and the piston 33 is reciprocated in the cylinder 37 so that A refrigerant is sucked into the compression chamber 41 and compressed.

  Further, one end of the shaft 19 is immersed in the lubricating oil 3, and the lubricating oil 3 is supplied to each part of the compression element 17 by the oil supply mechanism 28 as the shaft 19 rotates to lubricate the sliding part.

  Further, as shown in FIG. 6, the lubricating oil 3 that has flowed out from the upper end of the main bearing extension 57 flows through the gaps between the main bearing extension 57 and the thrust ball bearing 59, and the balls 65, the upper race 61, and the lower race 69. Lubricate.

  The thrust ball bearing 59 has less friction than a generally used sliding bearing, and has recently been increasingly used for the purpose of improving efficiency.

JP 2005-500476 Gazette

  However, in the conventional configuration, the lubricating oil 3 supplied from the main shaft portion 23 is scattered from the gap between the upper race 61 and the ball 65 to the outer peripheral side by the centrifugal force because the upper race 61 rotates together with the shaft 19, and the lower race 69. Thus, there is a problem in reliability that the ball 65 and the lower race 69 are damaged due to insufficient oil supply.

  The present invention solves the above-described conventional problems, and by providing sufficient lubrication to the lower race, the contact state between the ball and the lower race is stabilized, and the ball and the lower race are prevented from being damaged. An object of the present invention is to provide a hermetic compressor with improved performance.

In order to solve the above-mentioned conventional problems, the hermetic compressor of the present invention includes a main bearing extension and a thrust ball bearing disposed on the outer periphery of the main bearing extension on the upper surface of the thrust surface, and the shaft has one end. An oil supply path is formed which communicates with the lubricating oil stored in the sealed container and the other part opens to the upper end of the eccentric shaft part through an oil supply mechanism provided in the main shaft part, and the thrust surface is provided with an oil fence provided on the outer peripheral part. An oil storage groove is formed with the main bearing extension, and an oil discharge mechanism is provided at the bottom of the oil storage groove. It is supplied from the main shaft and scattered from the gap between the upper race and the ball to the outer periphery due to centrifugal force. Lubricating oil is collected by an oil fence provided on the outer periphery of the thrust surface, stored in the oil storage groove, and sufficient lubricating oil can be supplied to the lower race, so that the contact state between the ball and the lower race is stabilized, and the ball and lower It has the effect of being able to prevent damage to the nest. Furthermore, since the metal powder staying at the bottom of the oil storage groove can be discharged by the oil discharge mechanism, the metal powder can be removed from the lubricating oil supplied to the lower race, so that the lower race and the ball can be prevented from being damaged. Have.

  The hermetic compressor of the present invention is reliable by preventing damage to the lower race by supplying sufficient lubricant from the oil storage groove to the lower race and removing metal powder from the lubricant by the oil discharge mechanism. Can be improved.

1 is a longitudinal sectional view of a hermetic compressor according to Embodiment 1 of the present invention. Main part enlarged view in the same embodiment Schematic diagram showing the flow of lubricating oil in the vicinity of the oil storage groove in the same embodiment Longitudinal sectional view of hermetic compressor described in Patent Document 1 Enlarged view of relevant parts described in Patent Document 1 Schematic showing the flow of lubricating oil near the main bearing extension described in Patent Document 1

  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 includes the rotor A cylinder block having a shaft having a fixed main shaft portion and an eccentric shaft portion, a cylinder forming a compression chamber, a main bearing provided on the cylinder block for supporting the main shaft portion, and an upper portion of the main bearing A thrust surface provided on the thrust surface, a main bearing extension provided on an upper portion of the thrust surface, and a thrust ball bearing disposed on an outer peripheral portion of the main bearing extension on an upper surface of the thrust surface. The bearing includes a ball bearing having a plurality of balls held in a holder portion, and an upper race and a lower race respectively disposed above and below the ball bearing. The shaft forms an oil supply path having one end communicating with the lubricating oil and the other end opened to an upper end of the eccentric shaft portion through an oil supply mechanism provided in the main shaft portion, and the thrust surface is an oil provided on an outer peripheral portion. An oil storage groove is formed between the fence and the main bearing extension, and an oil discharge mechanism is provided at the bottom of the oil storage groove. The outer periphery of the outer race and the ball is supplied from the main shaft by centrifugal force. The lubricating oil splashed to the side is collected by the oil fence provided on the outer periphery of the thrust surface, stored in the oil storage groove, and sufficient lubricating oil can be supplied to the lower race, so that the contact state between the ball and the lower race is stabilized, Since damage to the ball and lower race can be prevented, reliability can be improved. Furthermore, since the metal powder staying at the bottom of the oil storage groove can be discharged by the oil discharge mechanism, it is possible to remove the metal powder from the lubricating oil supplied to the lower race, so that it is more reliable by preventing damage to the lower race. Can be improved.

  In the second invention, since the oil discharge mechanism of the hermetic compressor according to the first invention is formed by a through hole, the oil discharge mechanism can be easily formed by an inexpensive processing facility, so that productivity can be improved. it can.

  According to a third aspect of the present invention, the eccentric shaft portion of the hermetic compressor according to the first or second aspect of the present invention seals the tip opening, so that no lubricating oil is discharged from the tip opening and flows out from the main bearing extension. Since the amount of lubricating oil increases, sufficient lubricating oil can be supplied to the lower race, so that the contact state between the ball and the lower race is further stabilized, and the reliability is improved by preventing damage to the ball and the lower race. Can do.

According to a fourth aspect of the present invention, when the electric element of the hermetic compressor according to any one of the first to third aspects is driven at a plurality of operating frequencies by an inverter, particularly when the amount of oil supplied from the main shaft portion is small at a low speed. However, by storing lubricating oil in the oil storage groove, it is possible to supply sufficient lubricating oil to the lower race, so that the contact state between the ball and the lower race is stabilized and the ball and lower race are prevented from being damaged. Can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments.

(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 in the same embodiment. FIG. 3 is a schematic diagram showing the flow of lubricating oil in the vicinity of the oil storage groove in the same embodiment.

  In FIGS. 1 to 3, in the sealed container 101, the lubricating oil 103 is stored at the bottom, and the compressor main body 105 is elastically supported by the suspension spring 107. The sealed container 101 is filled with R600a (isobutane), which is a refrigerant with a low global warming potential.

  The compressor main body 105 includes an electric element 111 that includes a stator 113 and a rotor 115, and a compression element 117 that is disposed above the electric element 111. The sealed container 101 includes a terminal 126 and is connected to the electric element 111 by a lead wire (not shown). The compressor body 105 is attached to an inverter circuit (not shown) for driving at a plurality of operating frequencies.

  The shaft 119 constituting the compression element 117 includes a main shaft portion 123, a flange portion 121 provided at the upper end of the main shaft portion 123, and an eccentric shaft portion 125 extending from the upper surface of the flange portion 121. A tip opening 127 is provided at the upper end of the eccentric shaft 125, the main shaft 123 is rotatably supported by the main bearing 131 of the cylinder block 129, and the rotor 115 is fixed by shrink fitting or the like. .

  And it has the structure of the cantilever bearing supported with the main shaft part 123 and the main bearing 131 which are arrange | positioned under the eccentric shaft part 125 with respect to the eccentric shaft part 125 which receives a compressive load.

  Further, the shaft 119 includes an oil supply mechanism 128 including a spiral groove provided on the surface of the main shaft portion 123.

  In the present embodiment, the tip opening 127 of the eccentric shaft 125 is sealed with the sealing lid 186.

  The piston 133 is reciprocally inserted into a cylinder 137 having a substantially cylindrical inner surface formed in the cylinder block 129. Further, the connecting means 143 connects the eccentric shaft portion 125 and the piston 133 by fitting the hole portions provided at both ends into the piston pin 135 and the eccentric shaft portion 125 respectively attached to the piston 133.

  The cylinder 137 and the piston 133 form a compression chamber 141 together with the valve plate 139 attached to the opening end surface of the cylinder 137. Further, a cylinder head 153 is fixed so as to cover the valve plate 139 and cover it.

  The suction muffler 155 is molded of a resin such as PBT, forms a sound deadening space 156, and is sandwiched between the cylinder head 153 and the valve plate 139.

  Next, the thrust ball bearing 159 will be described.

  The main bearing 131 includes a thrust surface 116 that is a flat portion perpendicular to the shaft center, and a main bearing extension 157 that extends further upward than the thrust surface 116 and has an inner surface facing the main shaft portion 123.

  A thrust ball bearing 159 is stacked on the upper surface of the thrust surface 116 so as to surround the main bearing extension 157 in a state where a lower race 169, a ball bearing 163 composed of a holder 167 and a ball 165, and an upper race 161 are in contact with each other. Has been.

  The upper race 161 and the lower race 169 are annular and metal flat plates whose upper and lower surfaces are parallel.

  The holder 167 is formed of a resin material such as polyamide, has an annular shape, and has a plurality of holes in which the balls 165 are slidably accommodated.

  Next, the oil storage groove 184 will be described.

  The oil storage groove 184 is formed by a main bearing extension 157 of the cylinder block 129, a thrust surface 116, and an oil fence 180 disposed on the outer periphery of the thrust surface 116. The oil fence 180 is formed up to the height of the upper race 161. In addition, an oil discharge mechanism 182 formed with a through-hole capable of discharging metal powder collected at the bottom of the oil storage groove 184 is disposed at the bottom of the oil storage groove 184.

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

  When the electric element 111 is energized from the power terminal 109, the rotor 115 rotates together with the shaft 119 by the magnetic field generated in the stator 113. The electric element 111 is driven at a plurality of operating frequencies by an inverter circuit (not shown). As the main shaft portion 123 rotates, the eccentric shaft portion 125 rotates eccentrically, and the connecting means 143 converts the piston 133 into a reciprocating motion in the cylinder 137. By the reciprocating motion of the piston 133 in the cylinder 137, the volume of the compression chamber 141 changes, whereby the refrigerant in the sealed container 101 is sucked into the compression chamber 141 and compressed.

  In the suction stroke accompanying this compression operation, the refrigerant in the sealed container 101 is intermittently sucked into the compression chamber 141 via the suction muffler 155 and compressed in the compression chamber 141, and then the high-temperature and high-pressure refrigerant is sealed. It is sent from the container 101 to a refrigeration cycle (not shown).

  Next, the thrust ball bearing 159 will be described.

  The thrust ball bearing 159 has a plurality of balls 165 of the same size arranged between the flat upper race 161 and the lower race 169 so that each of them rolls in a point contact state. The efficiency of the hermetic compressor can be improved by reducing the sliding loss.

  Next, the flow of the lubricating oil 103 will be described.

One end of the shaft 119 is immersed in the lubricating oil 103, and when the shaft 119 rotates, the lubricating oil 103 is supplied to each part of the compression element 117 by the oil supply mechanism 128 to lubricate the sliding portion. As shown in FIG. 3, the lubricating oil 103 that has flowed out from the upper end of the main bearing extension 157 flows through the gaps between the main bearing extension 157 and the thrust ball bearing 159 and lubricates.

  In the present embodiment, the lubricating oil 103 supplied from the main shaft portion 123 and scattered by the centrifugal force from the gap between the upper race 161 and the ball 165 to the outer peripheral side is recovered by the oil fence 180 provided on the outer periphery of the thrust surface 116, and the oil storage groove It is stored in 184 and sufficient lubricating oil 103 can be supplied to the lower race 169. Therefore, the contact state between the ball 165 and the lower race 169 is stabilized, and the ball 165 and the lower race 169 can be prevented from being damaged. Further, since the metal powder staying at the bottom of the oil storage groove 184 can be discharged by the oil discharge mechanism 182, the metal powder can be removed from the lubricating oil 103 supplied to the lower race 169, so that the lower race 169 and the ball 165 are damaged. Can be prevented.

  In the present embodiment, the oil discharge mechanism 182 is formed at the bottom of the oil storage groove 184 with a through hole. By forming the through hole, the oil discharge mechanism 182 can be easily formed with simple processing equipment such as a drilling machine, so that productivity can be improved.

  Further, in the present embodiment, the eccentric shaft portion 125 seals the tip opening portion 127, so that the lubricating oil 103 is not discharged from the tip opening portion 127, and the amount of the lubricating oil 103 flowing out from the main bearing extension portion 157 is reduced. To increase. Therefore, since sufficient lubricating oil 103 can be supplied to the lower race 169, the contact state between the ball 165 and the lower race 169 can be further stabilized and the reliability can be improved by preventing damage to the ball 165 and the lower race 169. it can.

  In the present embodiment, electric element 111 is driven at a plurality of operating frequencies by an inverter circuit. In particular, when operating at a low operating frequency, the supply of the lubricating oil 103 from the main shaft portion 123 is reduced, but by storing the lubricating oil 103 in the oil storage groove 184, sufficient lubricating oil 103 is supplied to the lower race 169. it can. As a result, the contact state between the ball 165 and the lower race 169 is stabilized, and the reliability can be improved by preventing the ball 165 and the lower race 169 from being damaged.

  In the present embodiment, the electric element 111 is driven at a plurality of operating frequencies by an inverter circuit, but the same effect can be obtained even by a system driven only at the same operating frequency as the power supply frequency.

  As described above, the hermetic compressor according to the present invention prevents damage to the lower race by supplying sufficient lubricating oil from the oil storage groove to the lower race and removing metal powder from the lubricating oil by the oil discharge mechanism. Thus, the reliability can be improved, so that it can be widely applied not only to home electric refrigerator-freezers but also to air conditioners, vending machines and other refrigeration apparatuses.

DESCRIPTION OF SYMBOLS 101 Airtight container 103 Lubricating oil 111 Electric element 113 Stator 115 Rotor 116 Thrust surface 117 Compression element 119 Shaft 123 Main shaft part 125 Eccentric shaft part 128 Oil supply mechanism 127 End opening part 129 Cylinder block 131 Main bearing 133 Piston 141 Compression chamber 143 Connection Means 157 Main bearing extension 159 Thrust ball bearing 161 Upper race 163 Ball bearing 165 Ball 167 Holder 169 Lower race 180 Oil fence 182 Oil discharge mechanism 184 Oil storage groove

Claims (4)

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 a main shaft portion to which the rotor is fixed. And a cylinder block having a shaft having an eccentric shaft portion, a cylinder forming a compression chamber, a main bearing provided on the cylinder block for supporting the main shaft portion, and a thrust provided on an upper portion of the main bearing A thrust bearing provided on the outer periphery of the main bearing extension on the upper surface of the thrust surface, and a thrust ball bearing, A ball bearing having a plurality of balls held by a holder portion, and an upper race and a lower race respectively disposed above and below the ball bearing; An oil fence in which one end communicates with the lubricating oil and the other end opens through the oil supply mechanism provided in the main shaft portion and opens to the upper end of the eccentric shaft portion, and the thrust surface is provided in the outer peripheral portion. A hermetic compressor in which an oil storage groove is formed between the main bearing extension portion and an oil discharge mechanism at the bottom of the oil storage groove. The hermetic compressor according to claim 1, wherein the oil discharge mechanism is formed by a through hole. The hermetic compressor according to claim 1, wherein the eccentric shaft portion seals the opening at the tip. The hermetic compressor according to any one of claims 1 to 3, wherein the electric element is driven at a plurality of operating frequencies by an inverter circuit.