The present invention relates to a rotary compressor for use in a refrigeration cycle of an air conditioner device.
Rotary compressors include a compression unit that includes an annular cylinder provided with a suction port and a vane groove, an end plate that closes an end portion of the cylinder, an annular piston that is fitted to an eccentric portion of a rotating shaft rotationally driven by a motor and that revolves in the cylinder along a cylinder inner wall of the cylinder to form a working chamber with the cylinder inner wall, and a vane that protrudes into the working chamber from the inside of the vane groove provided in the cylinder and abuts on the annular piston to divide the working chamber into a suction chamber and a compression chamber, in which a discharge port is provided near the vane groove on the end plate to discharge a compressed refrigerant in the compression chamber to an outside of the compression chamber.
In rotary compressors having the above structure, the annular piston revolves in the cylinder and the vane moves in the vane groove as the rotationally driven rotating shaft rotates, so that sliding portions occur between the endplate and the annular piston and at other points in the working chamber. Therefore, it is necessary to take measures to improve sliding performance of the sliding portions.
For the measures, PTL 1 provides a recess in a sidewall portion of a vane to reduce a contact area with end plates, and retains lubricating oil in the recess to improve sliding performance of sliding portions.
However, in the conventional technology disclosed in PTL 1, there is no outlet for the lubricating oil retained in the recess of the sidewall portion of the vane to flow out of the recess, due to which sufficient lubricating oil is not supplied to the sliding portions between the end plates and the annular piston. Additionally, since the lubricating oil retained in the recess provided in the sidewall portion of the vane does not flow out, temperature of the lubricating oil retained in the recess rises due to sliding, and viscosity of the lubricating oil decreases, reducing lubricity and sealability in the working chamber.
In view of the above problems, the present invention provides a rotary compressor excellent in energy saving performance and reliability by actively supplying lubricating oil to sliding portions such as an annular piston and a vane in the working chamber of a rotary compressor to improve sliding performance of the sliding portions and ensure sealability in the working chamber.
According to one aspect of the present invention, there is provided with a rotary compressor including a motor arranged in a sealed container and a compression unit arranged in the sealed container and driven by the motor, the compression unit including: an annular cylinder configured to include a vane groove opening on an inner peripheral surface of the cylinder and communicating with an inside of the sealed container on an outer peripheral surface side of the cylinder; an end plate configured to close an end face-side opening of the cylinder; an annular piston fitted to an eccentric portion of a rotating shaft rotationally driven by the motor, the annular piston revolving in the cylinder along the inner peripheral surface of the cylinder to form a working chamber with the inner peripheral surface of the cylinder; a vane configured to protrude into the working chamber from an inside of the vane groove and abut on an outer peripheral surface of the annular piston at a leading end surface of the vane to divide the working chamber into a suction chamber and a compression chamber; a discharge port provided on the end plate on the compression chamber side; and a suction port opening on the inner peripheral surface of the cylinder on the suction chamber side, wherein an oil groove is formed at a position facing an end face of the vane on the end plate, one end side of the oil groove communicating with the inside of the sealed container, and an other end side of the oil groove being exposed in a gap between the leading end surface of the vane and the outer peripheral surface of the annular piston formed when the leading end surface of the vane is in abutment on the outer peripheral surface of the annular piston.
According to the present invention, an oil groove is formed at a position facing the end face of the vane on the end plate, in which one end side of the oil groove communicates with the inside of the sealed container, and the other end side of the oil groove is exposed in a gap between the leading end surface of the vane and the outer peripheral surface of the annular piston formed when the leading end surface of the vane is in abutment on the outer peripheral surface of the annular piston. Therefore, lubricating oil in the sealed container can flow out of the gap between the leading end surface of the vane and the outer peripheral surface of the annular piston formed when the leading end surface of the vane is in abutment on the outer peripheral surface of the annular piston through the oil groove. This allows for lubricating oil supply to sliding portions in the working chamber, enabling improved sliding performance of the sliding portions and ensured sealability in the working chamber.
An Example of a rotary compressor according to the present invention is described in detail with reference to the drawings. It should be noted that the present invention is not limited to the Example.
As illustrated in
A stator 111 of the motor 11 is formed in a cylindrical shape and is shrink-fitted and fixed to an inner peripheral surface of the compressor housing 10. A rotor 112 of the motor 11 is arranged inside the cylindrical stator 111, and is shrink-fitted and fixed to the rotating shaft 15 that mechanically connects the motor 11 to the compression unit 12.
The compression unit 12 includes a first compression unit 12S and a second compression unit 12T stacked above the first compression unit 12S. As illustrated in
As illustrated in
In the first cylinder 121S and the second cylinder 121T are formed a first vane groove 128S and a second vane groove 128T in a radial direction and over an entire cylinder height. The first vane groove 128S and the second vane groove 128T are open on the first cylinder inner wall 123S and the second cylinder inner wall 123T, and communicate with an inside of the compressor housing 10 on an outer peripheral surface 121Sa side of the first cylinder 121S and an outer peripheral surface 121Ta side of the second cylinder 121T. A first vane 127S and a second vane 127T each having a flat plate shape are slidably fitted into the first vane groove 128S and the second vane groove 128T.
As illustrated in
The first cylinder 121S and the second cylinder 121T are also formed with a first pressure introducing path 129S and a second pressure introducing path 129T that cause the far end of the first and second vane grooves 128S and 128T to communicate with the inside of the compressor housing 10 at an opening portion R illustrated in
The first cylinder 121S and the second cylinder 121T are provided with the first suction port 135S and the second suction port 135T that are open on the first cylinder inner wall 123S and the second cylinder inner wall 123T and that cause the first suction chamber 131S and the second suction chamber 131T to communicate with an outside in order to suction a refrigerant from the outside into the first suction chamber 131S and the second suction chamber 131T.
In addition, as illustrated in
A sub bearing portion 161S is formed on the lower end plate 160S, and a sub shaft portion 151 of the rotating shaft 15 is rotatably supported by the sub bearing portion 161S. A main bearing portion 161T is formed on the upper end plate 160T, and a main shaft portion 153 of the rotating shaft 15 is rotatably supported by the main bearing portion 161T.
The rotating shaft 15 includes a first eccentric portion 152S and a second eccentric portion 152T that are eccentric with a phase shift of 180° from each other. The first eccentric portion 152S is rotatably fitted to the first annular piston 125S of the first compression unit 12S, and the second eccentric portion 152T is rotatably fitted to the second annular piston 125T of the second compression unit 12T.
When the rotating shaft 15 rotates, the first annular piston 125S and the second annular piston 125T revolve counterclockwise in
As illustrated in
The lower muffler chamber 180S is a space formed in an annular shape, and is a part of a communication passage that allows a discharge side of the first compression unit 12S to communicate with an inside of the upper muffler chamber 180T through a refrigerant passage 136 (see
As illustrated in
The first cylinder 121S, the lower end plate 160S, the lower muffler cover 170S, the second cylinder 121T, the upper end plate 160T, the upper muffler cover 170T, and the intermediate partition plate 140 are integrally fastened by a plurality of through bolts 175 and the like. In the compression unit 12 integrally fastened by the through bolts 175 and the like, an outer peripheral portion of the large diameter portion of the upper end plate 160T is secured by spot welding to the compressor housing 10 to fix the compression unit 12 to the compressor housing 10.
On an outer peripheral wall of the cylindrical compressor housing 10, first and second through holes 101 and 102 are provided apart axially and in order from the lower part in order to allow first and second suction pipes 104 and 105 to pass therethrough. In addition, on an outer side portion of the compressor housing 10, an accumulator 25 composed of an independent cylindrical sealed container is held by an accumulator holder 252 and an accumulator band 253.
A system connection pipe 255 connected to an evaporator of a refrigeration cycle is connected to a top part center of the accumulator 25. A bottom through hole 257 provided at a bottom of the accumulator 25 is connected to a first low-pressure connection pipe 31S and a second low-pressure connection pipe 31T, one end of which is extended to an internal upper part of the accumulator 25, and an other end of which is connected to an other end of the first suction pipe 104 and the second suction pipe 105.
The first low-pressure connection pipe 31S and the second low-pressure connection pipe 31T, which guide a low-pressure refrigerant of the refrigeration cycle to the first compression unit 12S and the second compression unit 12T via the accumulator 25, are connected to the first suction port 135S and the second suction port 135T (see
A discharge pipe 107, which serves as a discharge unit that is connected to the refrigeration cycle and that discharges a high-pressure refrigerant gas to a condenser side of the refrigeration cycle, is connected to a top part of the compressor housing 10. In other words, the first discharge port 190S and the second discharge port 190T are connected to the condenser of the refrigeration cycle.
Lubricating oil is sealed in the compressor housing 10 approximately up to the height of the second cylinder 121T. Additionally, the lubricating oil is sucked up through an oil supply pipe 16 attached to a lower end portion of the rotating shaft 15 by a vane pump (not illustrated) inserted into a lower part of the rotating shaft 15, and circulates through the compression unit 12, lubricating sliding components and sealing minute gaps in the compression unit 12.
Next, an oil groove according to the present invention is described with reference to
The one end side of the linearly extending oil groove 165 extends to the outer peripheral surface of the end plate 160 (the outer peripheral surface of the small diameter portion 162 in the case of the upper end plate 160T) facing the internal space of the compressor housing 10, and has an opening portion 166 opening on the outer peripheral surface of the end plate 160. Therefore, the oil groove 165 communicates with the internal space in the high-pressure atmosphere state of the compressor housing 10 via the opening portion 166.
The other end side of the linearly extending oil groove 165 extends into the working chamber 130. The other end side of the oil groove 165 is located at a position such that when the annular piston 125 is at a top dead center position, the other end side thereof is not exposed to an inner periphery 125u side of the annular piston 125 and is covered by an end face of the annular piston 125, while when the annular piston 125 is at a bottom dead center position, it is covered by the end face 127f of the vane 127. The radially extending oil groove 165 needs only to be exposed in the compression chamber at any position between the top dead center of the annular piston and the bottom dead center thereof, and does not have to be exposed at all times. In the present Example, a leading end surface 127a is a curved surface, but may also be a flat surface.
A leading end of the vane 127 on the annular piston 125 side has a curved leading end surface 127a. Between the leading end surface 127a and an outer peripheral surface 125a of the annular piston 125, a gap 167 is formed when the leading end surface 127a is in abutment on the outer peripheral surface 125a, and the oil groove 165 is exposed in the gap 167. In the present Example, the leading end surface 127a is curved, but may also be flat.
The opening portion 166 of the oil groove 165 serves as an inlet for lubricating oil, and the gap 167 in which the oil groove 165 is exposed serves as an outlet for the lubricating oil. Accordingly, the lubricating oil in the high-pressure atmosphere state of the compressor housing 10 flows in through the opening portion 166, flows out through the gap 167, and can be supplied to sliding portions.
Since the oil groove 165 is located on the compression chamber 133 side rather than on the widthwise center side of the vane 127, the gap 167 is arranged on the compression chamber 133 side relative to a contact point between the leading end surface 127a and the outer peripheral surface 125a. By arranging the gap 167 on the compression chamber 133 side, a pressure difference between the opening portion 166 and the gap 167 does not become too large, which can prevent inflow of a large amount of a refrigerant. In addition, in the present Example, the entire oil groove 165 is located on the compression chamber side rather than on the widthwise center side of the vane 127 to arrange the gap 167 on the compression chamber 133 side relative to the contact point between the leading end surface 127a and the outer peripheral surface 125a. However, as long as the gap 167 is located on the compression chamber 133 side relative to the contact point between the leading end surface 127a and the outer peripheral surface 125a, the oil groove 165 may be arranged, for example, diagonally with respect to the vane 127 to arrange the gap 167 on the compression chamber 133 side without locating the entire oil groove 165 on the compression chamber 133 side rather than on the widthwise center side of the vane 127.
Additionally, in the present Example, the gap 167 is arranged on the compression chamber 133 side relative to the contact point between the leading end surface 127a and the outer peripheral surface 125a, but may be arranged on the suction chamber 131 side or arranged on the compression chamber 133 side and the suction chamber side. The arrangement of the gap 167 may be determined so that the pressure difference between pressure at the opening portion 166 and pressure at the gap 167 is suitable for lubricating oil supply.
In addition, in the present Example, the end portion of the oil groove 165 on the end plate center side, which is the other end side thereof, extends into the working chamber 130. However, the end portion on the other end side of the oil groove 165 does not have to be extended into the working chamber 130 as long as the oil groove 165 is exposed in the gap 167 formed when the leading end surface 127a is in abutment on the outer peripheral surface 125a. For example, even when the end portion on the other end side of the oil groove 165 is located in the vane groove 128 and immediately before the working chamber 130, the oil groove 165 can be exposed in the gap 167 when the annular piston 125 is at the top dead center position as long as the leading end surface 127a of the vane 127 is curved. Thus, when the annular piston 125 comes to the top dead center position, the lubricating oil flowing in through the opening portion 166 can flow out through the gap 167.
In the present Example, the oil groove 165 is formed not on the intermediate partition plate 140 but on the end face of the end plate 160S that closes the lower end portion-side opening of the cylinder 121S and the end face of the end plate 160T that closes the upper end portion-side opening of the cylinder 121T. However, the oil groove 165 may be formed not on the end plates 160S and 160T but on end faces of the intermediate partition plate 140 that closes an upper end portion-side opening of the cylinder 121S and a lower end portion-side opening of the cylinder 121T. However, for a reason described below, the oil groove 165 is preferably formed on the end face of the end plate 160S closing the lower end portion-side opening of the cylinder 121S and the end face of the end plate 160T closing the upper end portion-side opening of the cylinder 121T.
In
While the present invention has been described with reference to the limited number of embodiments, the scope of rights of the present invention is not limited thereto. Modifications of the embodiments based on the above disclosure are obvious to those skilled in the art.
Number | Date | Country | Kind |
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2020-061246 | Mar 2020 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2021/013691 | 3/30/2021 | WO |