Patent Description:
A rotary compressor is used in a refrigeration cycle apparatus such as an air conditioner. In the rotary compressor, a refrigerant is compressed in such a manner that an eccentric portion of a rotary shaft is eccentrically rotated by a compression mechanism.

In this type of the rotary compressor, the rotary shaft has a supply channel for supplying a lubricating oil stored inside a case to a sliding portion between the rotary shaft and a bearing. However, when the refrigerant compressed by the compression mechanism enters the supply channel, there is a possibility that desired lubrication performance may not be obtained.

<CIT> discloses a rotary compressor comprising:.

<CIT> relates to a rotary compressor including a casing in the lower part of which an oil reservoir space is formed, cylinders, pistons forming suction compression chambers in the cylinders, a shaft connected to the pistons, and an upper bearing journaling the shaft. In the shaft, a first contact surface contacting the upper bearing is formed. In the first contact surface, an oil groove is formed extending downward from the upper part of the first contact surface to the cylinders. Inside the shaft, there are formed an oil supply main pathway into which oil flows from the oil reservoir space, second and third oil supply sub pathways through which the oils flows from the oil supply main pathway to the suction compression chamber, and a first oil supply sub pathways which is communicated with the upper part of the oil groove. The compressor comprises a cover at a position below a bearing, the cover having a through-hole, and a shaft with a portion protruding downward from the through-hole. There is no balancer at a position below said bearing, and said cover is not a balancer cover. <CIT>, <CIT>, <CIT>, <CIT> disclose further compressors with a similar arrangement.

An object of the present invention is to provide a rotary compressor, a method for manufacturing a rotary compressor, and a refrigeration cycle apparatus which are capable of obtaining desired lubrication performance.

A rotary compressor according to an embodiment includes a case, a rotary shaft, a compression mechanism, a balancer, and a balancer cover. A lubricating oil is stored in the case. The rotary shaft is disposed inside the case, and has an eccentric portion. The compression mechanism has a cylinder, a main bearing, and an auxiliary bearing. The cylinder accommodates the eccentric portion. The main bearing rotatably supports the rotary shaft from above the cylinder. The auxiliary bearing rotatably supports the rotary shaft from below the cylinder. A through-hole is formed at a position of the balancer cover facing the rotary shaft in the axial direction. The rotary shaft has a thrust sliding portion, a protruding portion, and a supply channel. The thrust sliding portion of the rotary shaft comes into contact with a seal located around the through-hole of the balancer cover, in the axial direction, thereby blocking communication between the inside and the outside of the balancer cover through the through-hole. The protruding portion is located on an inner peripheral side of the thrust sliding portion, and protrudes downward from the through-hole through the through-hole. The supply channel is open on a lower end surface of the protruding portion to guide the lubricating oil. The rotary shaft is displaceable by a predetermined distance in the axial direction with respect to the compression mechanism. The protruding portion protrudes from the lower end of the through-hole to be longer than the predetermined distance.

Hereinafter, a rotary compressor according to an embodiment, a method for manufacturing a rotary compressor, and a refrigeration cycle apparatus will be described with reference to the drawings.

First, a refrigeration cycle apparatus <NUM> will briefly be described. <FIG> is a schematic configuration diagram of the refrigeration cycle apparatus <NUM> including a sectional view of a rotary compressor <NUM> according to a first embodiment.

As shown in <FIG>, the refrigeration cycle apparatus <NUM> according to the present embodiment includes the rotary compressor <NUM>, a condenser <NUM> serving as a radiator connected to the rotary compressor <NUM>, an expansion device <NUM> connected to the condenser <NUM>, and an evaporator <NUM> serving as a heat absorber connected between the expansion device <NUM> and the rotary compressor <NUM>.

The rotary compressor <NUM> is a so-called rotary-type compressor. The rotary compressor <NUM> compresses an internally fetched low-pressure gas refrigerant and obtains a high-temperature and high-pressure gas refrigerant. A specific configuration of the rotary compressor <NUM> will be described later.

The condenser <NUM> dissipates heat from the high-temperature and high-pressure gas refrigerant fed from the rotary compressor <NUM>, and obtains a high-pressure liquid refrigerant.

The expansion device <NUM> lowers a pressure of the high-pressure liquid refrigerant fed from the condenser <NUM> and obtains a low-temperature and low-pressure liquid refrigerant.

The evaporator <NUM> vaporizes the low-temperature and low-pressure liquid refrigerant fed from the expansion device <NUM> and changes the low-temperature and low-pressure liquid refrigerant into a low-pressure gas refrigerant. In the evaporator <NUM>, when the low-pressure liquid refrigerant vaporizes, heat of vaporization is taken from surroundings, and the surroundings are cooled. The low-pressure gas refrigerant passing through the evaporator <NUM> is fetched into the above-described rotary compressor <NUM>.

In this way, in the refrigeration cycle apparatus <NUM> according to the present embodiment, the refrigerant serving as a working fluid circulates while changing a phase between the gas refrigerant and the liquid refrigerant. In the refrigeration cycle apparatus <NUM> according to the present embodiment, as the refrigerant, it is possible to use an HFC-based refrigerant such as R410A and R32, an HFO-based refrigerant such as R1234yf and R1234ze, or a natural refrigerant such as CO<NUM>.

Next, the above-described rotary compressor <NUM> will be described.

The rotary compressor <NUM> according to the present embodiment includes a compressor body <NUM> and an accumulator <NUM>.

The accumulator <NUM> is a so-called gas-liquid separator. The accumulator <NUM> is provided between the above-described evaporator <NUM> and the compressor body <NUM>. The accumulator <NUM> is connected to the compressor body <NUM> through a suction pipe <NUM>. The accumulator <NUM> supplies only the gas refrigerant to the compressor body <NUM>, out of the gas refrigerant vaporized by the evaporator <NUM> and the liquid refrigerant not vaporized by the evaporator <NUM>.

The compressor body <NUM> includes a rotary shaft <NUM>, an electric motor unit <NUM>, a compression mechanism <NUM>, and a case <NUM> for accommodating the rotary shaft <NUM>, the electric motor unit <NUM>, and the compression mechanism <NUM>. The compressor body <NUM> according to the present embodiment is disposed in a state where an axial direction of the rotary shaft <NUM> is an upward-downward direction.

The case <NUM> is formed in a cylindrical shape, and both end portions in the axial direction are closed. A lubricating oil J is accommodated inside the case <NUM>. A portion of the compression mechanism <NUM> is immersed into the lubricating oil J.

The rotary shaft <NUM> is disposed coaxially with an axis line O of the case <NUM>. In the following description, a direction extending along the axis line O will simply be referred to as the axial direction, a direction orthogonal to the axial direction will be referred to as a radial direction, and a direction turning around the axis line O will be referred to as a circumferential direction.

The electric motor unit <NUM> is disposed on a first side inside the case <NUM> in the axial direction. The compression mechanism <NUM> is disposed on a second side inside the case <NUM> in the axial direction. In the following description, the electric motor unit <NUM> side along the axial direction will be referred to as an upper side, and the compression mechanism <NUM> side will be referred to as a lower side.

The electric motor unit <NUM> is a so-called inner rotor type DC brushless motor. Specifically, the electric motor unit <NUM> includes a stator <NUM> and a rotor <NUM>.

The stator <NUM> is fixed to an inner wall surface of the case <NUM> by means of shrink fitting.

The rotor <NUM> is fixed to an upper portion of the rotary shaft <NUM> in a state where an interval is formed inside the stator <NUM> in the radial direction.

A counter bore <NUM> is formed in an inner peripheral portion on a lower surface of the rotor <NUM>. The counter bore <NUM> is an annular recess portion recessed upward from the lower surface of the rotor <NUM>, and formed over an entire periphery of the rotor <NUM>. A balancer <NUM> is provided in an outer peripheral portion on the lower surface of the rotor <NUM>. For example, the balancer <NUM> is formed in an arc shape in a plan view when viewed in the axial direction. The balancer <NUM> is provided in a portion in the circumferential direction on the lower surface of the rotor <NUM>.

The compression mechanism <NUM> includes a cylinder <NUM> having a cylindrical shape through which the rotary shaft <NUM> penetrates, and a main bearing <NUM> and an auxiliary bearing <NUM> which individually close both end opening portions of the cylinder <NUM> and rotatably support the rotary shaft <NUM>. A space formed by the cylinder <NUM>, the main bearing <NUM>, and the auxiliary bearing <NUM> forms a cylinder chamber <NUM>.

An eccentric portion <NUM> eccentric in the radial direction with respect to the axis line O is formed in a portion located inside the cylinder chamber <NUM> in the above-described rotary shaft <NUM>. In the present embodiment, an eccentric direction of the eccentric portion <NUM> is set on a side opposite to the balancer <NUM> across the axis line O.

A roller <NUM> is externally inserted into the eccentric portion <NUM>. The roller <NUM> is configured to be eccentrically rotatable with respect to the axis line O while an outer peripheral surface is in sliding contact with an inner peripheral surface of the cylinder <NUM> as the rotary shaft <NUM> is rotated.

<FIG> is a sectional view of the compression mechanism <NUM> corresponding to line II-II in <FIG>.

As shown in <FIG>, in the cylinder <NUM>, a blade groove <NUM> recessed outward in the radial direction is formed in a portion in the circumferential direction. The blade groove <NUM> is formed over in the axial direction (upward-downward direction) of the cylinder <NUM>. The blade groove <NUM> communicates with the inside of the case <NUM> in an outer end portion in the radial direction.

A blade <NUM> is provided in the blade groove <NUM>. The blade <NUM> is configured to be slidable in the radial direction with respect to the cylinder <NUM>. The blade <NUM> is biased inward in the radial direction by a biasing member (not shown). An inner end surface of the blade <NUM> in the radial direction is in contact with an outer peripheral surface of the roller <NUM> inside the cylinder chamber <NUM>. In this manner, the blade <NUM> moves forward and rearward inside the cylinder chamber <NUM> as the roller <NUM> is eccentrically rotated.

The cylinder chamber <NUM> is divided into a suction chamber 46a and a compression chamber 46b by the roller <NUM> and the blade <NUM>. In the compression mechanism <NUM>, a compression operation is performed inside the cylinder chamber <NUM> by a rotation operation of the roller <NUM> and a forward/rearward operation of the blade <NUM>.

In the cylinder <NUM>, a suction hole <NUM> that penetrates the cylinder <NUM> in the radial direction is formed in a portion located on an inner side (left side of the blade groove <NUM> in <FIG>) of the blade groove <NUM> along a rotation direction of the roller <NUM> (refer to an arrow in <FIG>). The above-described suction pipe <NUM> (refer to <FIG>) is connected to the suction hole <NUM> from an outer end portion in the radial direction. On the other hand, an inner end portion of the suction hole <NUM> in the radial direction is open into the cylinder chamber <NUM> (suction chamber 46a).

The main bearing <NUM> closes an upper end opening portion of the cylinder <NUM>. The main bearing <NUM> rotatably supports a portion located above the cylinder <NUM> in the rotary shaft <NUM>. Specifically, the main bearing <NUM> includes a cylinder portion <NUM> into which the rotary shaft <NUM> is inserted, and a flange portion <NUM> protruding outward in the radial direction from a lower end portion of the cylinder portion <NUM>.

An upper end portion of the cylinder portion <NUM> is accommodated inside the above-described counter bore <NUM>. In this manner, the rotary compressor <NUM> (compressor body <NUM>) is miniaturized in the axial direction.

A main bearing discharge hole <NUM> that penetrates the flange portion <NUM> in the axial direction is formed in a portion of the flange portion <NUM> in the circumferential direction. The main bearing discharge hole <NUM> communicates with the inside of the cylinder chamber <NUM> (compression chamber 46b). A discharge valve mechanism <NUM> is disposed in the flange portion <NUM>. The discharge valve mechanism <NUM> opens the main bearing discharge hole <NUM> as the pressure inside the cylinder chamber <NUM> (compression chamber 46b) increases, and discharges the refrigerant outward of the cylinder chamber <NUM>.

The main bearing <NUM> is provided with a muffler <NUM> that covers the main bearing <NUM> from above. A communication hole <NUM> that causes the inside and the outside of the muffler <NUM> to communicate with each other is formed in a central portion of the muffler <NUM> in the radial direction. The high-temperature and high-pressure gas refrigerant discharged through the above-described discharge hole <NUM> is discharged into the case <NUM> through the communication hole <NUM>.

The auxiliary bearing <NUM> closes a lower end opening portion of the cylinder <NUM>. The auxiliary bearing <NUM> rotatably supports a portion located below the cylinder <NUM> in the rotary shaft <NUM>. Specifically, the auxiliary bearing <NUM> includes a cylinder portion <NUM> into which the rotary shaft <NUM> is inserted, and a flange portion <NUM> protruding outward in the radial direction from the upper end portion of the cylinder portion <NUM>.

An auxiliary bearing discharge hole <NUM> that penetrates the flange portion <NUM> in the axial direction is formed in a portion of the flange portion <NUM> in the circumferential direction. The auxiliary bearing discharge hole <NUM> communicates with the inside of the cylinder chamber <NUM> (compression chamber 46b). A discharge valve mechanism <NUM> is provided in the flange portion <NUM>. The discharge valve mechanism <NUM> opens the auxiliary bearing discharge hole <NUM> as the pressure inside the cylinder chamber <NUM> (compression chamber 46b) increases and discharges the refrigerant outward of the cylinder chamber <NUM>.

The auxiliary bearing <NUM> is provided with a balancer cover <NUM> that covers the auxiliary bearing <NUM> from below. The balancer cover <NUM> is formed in a bottomed cylindrical shape that is open upward. A seal <NUM> is formed in a central portion in the radial direction in a bottom portion of the balancer cover <NUM>. The seal <NUM> is formed to bulge upward with respect to an outer peripheral portion in the bottom portion of the balancer cover <NUM>. However, the seal <NUM> may not bulge from the bottom portion of the balancer cover <NUM>. An upper surface of the seal <NUM> is formed to have a flat surface orthogonal to the axis line O. A through-hole <NUM> that penetrates the seal <NUM> in the axial direction is formed in a central portion (portion located on the axis line O) of the seal <NUM>.

The main bearing <NUM>, the cylinder <NUM>, and the auxiliary bearing <NUM> have a communication hole <NUM> for causing the inside of the inside of the muffler <NUM> and the inside of the balancer cover <NUM> to communicate with each other. The communication hole <NUM> penetrates the main bearing <NUM>, the cylinder <NUM>, and the auxiliary bearing <NUM> in the axial direction at a position where the communication hole <NUM> faces the above-described discharge holes <NUM> and <NUM> across the axis line O in the radial direction.

<FIG> is an enlarged view of a main part in <FIG>.

As shown in <FIG>, the rotary shaft <NUM> according to the present embodiment has a thrust sliding portion <NUM> and a protruding portion <NUM> located on an inner peripheral side of the thrust sliding portion <NUM> and protruding downward.

The rotary shaft <NUM> further has the above-described eccentric portion <NUM>, a main shaft portion <NUM>, and an auxiliary shaft portion <NUM>.

The main shaft portion <NUM> is a portion located above the eccentric portion <NUM> in the above-described rotary shaft <NUM>. The main shaft portion <NUM> is connected to an upper side of the eccentric portion <NUM> via a connecting portion 51a. The main shaft portion <NUM> is supported by the main bearing <NUM>, and the rotor <NUM> is fixed to the main shaft portion <NUM>.

On the other hand, the auxiliary shaft portion <NUM> is a portion located below the eccentric portion <NUM> in the rotary shaft <NUM>. The auxiliary shaft portion <NUM> is connected to a lower side of the eccentric portion <NUM> via a connecting portion 51b. The auxiliary shaft portion <NUM> is supported by the auxiliary bearing <NUM>. In the present embodiment, an outer diameter ϕDs of the auxiliary shaft portion <NUM> is smaller than an outer diameter ϕDm of the main shaft portion <NUM>. However, in the auxiliary shaft portion <NUM>, at least a portion protruding downward from the auxiliary bearing <NUM> may have a diameter smaller than that of the main shaft portion <NUM>. That is, a portion located inside the auxiliary bearing <NUM> in the auxiliary shaft portion <NUM> may have an outer diameter the same as that of the main shaft portion <NUM>.

The seal <NUM> of the balancer cover <NUM> receives an axial load acting on the rotary shaft <NUM> and supports the thrust sliding portion <NUM> of the rotary shaft <NUM> to be slidable. The thrust sliding portion <NUM> and the seal <NUM> come into contact with each other in the axial direction, thereby blocking communication between the inside and the outside of the balancer cover <NUM> through the through-hole <NUM>. The thrust sliding portion <NUM> according to the present embodiment is a lower end surface of the auxiliary shaft portion <NUM>. The thrust sliding portion <NUM> is a flat surface orthogonal to the axial direction. It is preferable that the thrust sliding portion <NUM> is pressed against the seal <NUM> by the weight of the rotary shaft <NUM> and the rotor <NUM>, or a magnetic force generated between the stator <NUM> and the rotor <NUM>. In the present embodiment, the base shaft portion is configured to include the eccentric portion <NUM>, the main bearing <NUM>, and the auxiliary bearing <NUM>.

A balancer <NUM> is attached to a portion protruding downward from the auxiliary bearing <NUM> in the auxiliary shaft portion <NUM>. For example, the balancer <NUM> is formed in a disk shape. An attachment hole <NUM> that penetrates the balancer <NUM> in the axial direction is formed at a position eccentric with respect to the center of the balancer <NUM>. The auxiliary shaft portion <NUM> of the rotary shaft <NUM> is fixed inside the attachment hole <NUM> by means of press-fitting. In this case, the center of the balancer <NUM> is eccentric with respect to the axis line O in a direction opposite to an eccentric direction of the eccentric portion <NUM> (direction the same as that of the balancer <NUM>). That is, the balancer <NUM> and the eccentric portion <NUM> are disposed with a phase difference of <NUM>° in the circumferential direction. The shape of the balancer <NUM> is not limited to the disc shape.

In this way, in the present embodiment, the balancer <NUM> is provided in the auxiliary shaft portion <NUM>. Accordingly, for example, compared to a case where the balancer is provided on an upper surface of the rotor <NUM>, a distance between the balancer <NUM> and the bearing (in the present embodiment, the auxiliary bearing <NUM>) can be shortened. In this manner, it is possible to suppress bending of the rotor <NUM>.

Here, in the compressor body <NUM>, a centrifugal force is generated in the eccentric portion <NUM> and the respective balancers <NUM> and <NUM> as the rotary shaft <NUM> is rotated. In this case, in order to stabilize rotational balance of the rotary shaft <NUM>, it is preferable to satisfy two Equations ((<NUM>) and (<NUM>)) below.

Specifically, a centrifugal force acting on the eccentric portion <NUM> is defined as F0, a centrifugal force acting on the balancer <NUM> is defined as F1, and a centrifugal force acting on the balancer <NUM> is defined as F2. In this case, it is preferable that a resultant force of the respective centrifugal forces F0, F1, and F2 becomes <NUM> (refer to Equation (<NUM>) below). The respective centrifugal forces F0, F1, and F2 can be calculated by mrω<NUM> (m: mass, r: distance in the radial direction from the axis line O, and ω: angular velocity).

The center of action of the centrifugal force F0 is defined as a reference point, a distance in the axial direction from the reference point to the center of action of the centrifugal force F1 is defined as L1, and a distance in the axial direction from the reference point to the center of action of the centrifugal force F2 is defined as L2. In this case, it is preferable that a sum of moments acting on the rotary shaft <NUM> due to the centrifugal forces F1 and F2 becomes <NUM> (refer to Equation (<NUM>) below).

In the present embodiment, it is preferable that the distance L1 in the axial direction from the reference point to the center of action of the centrifugal force F1 is equal to or longer than the distance L2 in the axial direction from the reference point to the center of action of the centrifugal force F2 (L1≥L2). In this manner, the balancer <NUM> can be miniaturized, and the amount of eccentricity can be reduced. As a result, the protruding amount of the balancer <NUM> in the radial direction with respect to the axis line O can be particularly suppressed, and the compressor body <NUM> in the radial direction can be miniaturized.

The protruding portion <NUM> protrudes downward from an inner peripheral portion of the thrust sliding portion <NUM>. The protruding portion <NUM> protrudes downward from a lower end opening edge of the through-hole <NUM> through the through-hole <NUM>. Specifically, the protruding portion <NUM> according to the present embodiment protrudes downward from a lowest point (lower surface of the seal <NUM>) of the balancer cover <NUM>. The rotary shaft <NUM> is displaced (backlash in the upward-downward direction) by a predetermined distance in the axial direction with respect to the compression mechanism <NUM>, due to a difference between the height of the cylinder chamber <NUM> and the length in the axial direction of the connecting portions 51a and 51b provided upward and downward of the eccentric portion <NUM> and the eccentric portion <NUM>. Therefore, in the present embodiment, the protruding amount from the lower end opening edge of the through-hole <NUM> of the protruding portion <NUM> is larger than the predetermined distance which is a displacement amount of the rotary shaft <NUM>. That is, even when the rotary shaft <NUM> is displaced in the upward-downward direction by the amount of backlash, the protruding amount of the protruding portion <NUM> is set so that the protruding portion <NUM> always protrudes downward from the lower end opening edge of the through-hole <NUM> of the balancer cover <NUM>.

The rotary shaft <NUM> has a supply channel <NUM> for supplying the lubricating oil J to each sliding portion in the compression mechanism <NUM> (for example, a portion between the eccentric portion <NUM> and the roller <NUM>, and a portion between the rotary shaft <NUM> and the bearings <NUM> and <NUM>). The supply channel <NUM> has a main flow path <NUM> extending coaxially with the axis line O, and sub-flow paths <NUM> and <NUM> extending in the radial direction from the main flow path <NUM>.

A lower end portion of the main flow path <NUM> is open on a lower end surface of the rotary shaft <NUM> (protruding portion <NUM>). In this manner, the lubricating oil J inside the case <NUM> can flow into the main flow path <NUM>.

An upper end portion of the main flow path <NUM> is terminated in a lower end portion of the main shaft portion <NUM>. However, the length in the axial direction of the main flow path <NUM> can appropriately be changed as long as the length reaches at least the cylinder <NUM>. For example, the main flow path <NUM> may penetrate the rotary shaft <NUM> in the axial direction. A twist plate that promotes the lubricating oil J to rise as the rotary shaft <NUM> is rotated may be provided on an inner peripheral surface of the main flow path <NUM>.

The first sub-flow path <NUM> is formed in a connecting portion (connecting portion 51a) between the main shaft portion <NUM> and the eccentric portion <NUM> in the rotary shaft <NUM>. An inner end portion in the radial direction of the first sub-flow path <NUM> communicates with the inside of the above-described main flow path <NUM>. On the other hand, an outer end portion in the radial direction of the first sub-flow path <NUM> is open outward in the radial direction on an outer peripheral surface of the rotary shaft <NUM>.

The second sub-flow path <NUM> is formed in a portion located inside the auxiliary bearing <NUM> in the auxiliary shaft portion <NUM>. An inner end portion in the radial direction of the second sub-flow path <NUM> communicates with the inside of the above-described main flow path <NUM>. On the other hand, an outer end portion in the radial direction of the second sub-flow path <NUM> is open outward in the radial direction on the outer peripheral surface of the rotary shaft <NUM>.

A lower circulation path <NUM> is formed on the outer peripheral surface of the rotary shaft <NUM> (auxiliary shaft portion <NUM>). The lower circulation path <NUM> is formed by a spiral groove formed on the outer peripheral surface of the rotary shaft <NUM>. A lower end portion of the lower circulation path <NUM> communicates with the inside of the second sub-flow path <NUM>. On the other hand, an upper end portion of the lower circulation path <NUM> is located in the upper end portion of the auxiliary shaft portion <NUM>. The lower circulation path <NUM> guides the lubricating oil J upward from below when the rotary shaft <NUM> is rotated. The lower circulation path <NUM> may be configured so that the lubricating oil J can be supplied between the outer peripheral surface of the auxiliary shaft portion <NUM> and the inner peripheral surface of the auxiliary bearing <NUM> (cylinder portion <NUM>). In this case, for example, a groove may be formed on the inner peripheral surface of the cylinder portion <NUM>. A shape or a layout of the lower circulation path <NUM> can appropriately be changed.

In the main bearing <NUM>, an upper circulation path (not shown) is formed on the inner peripheral surface of the cylinder portion <NUM>. The upper circulation path is formed in a spiral groove. The lower end portion of the upper circulation path communicates with the inside of the first sub-flow path <NUM>. On the other hand, the upper end portion of the upper circulation path communicates with the inside of the case <NUM>. The upper circulation path guides the lubricating oil J upward from below when the rotary shaft <NUM> is rotated. The upper circulation path may be formed on the outer peripheral surface of the main shaft portion <NUM>.

Next, an operation of the above-described rotary compressor <NUM> will be described.

As shown in <FIG>, when electric power is supplied to the stator <NUM> of the electric motor unit <NUM>, the rotary shaft <NUM> is rotated around the axis line O together with the rotor <NUM>. As the rotary shaft <NUM> is rotated, the eccentric portion <NUM> and the roller <NUM> are eccentrically rotated inside the cylinder chamber <NUM>. In this case, each of the rollers <NUM> comes into sliding contact with the inner peripheral surface of the cylinder <NUM>. In this manner, the gas refrigerant is fetched into the cylinder chamber <NUM> through the suction pipe <NUM>, and the gas refrigerant fetched into the cylinder chamber <NUM> is compressed.

Specifically, in the cylinder chamber <NUM>, the gas refrigerant is suctioned into the suction chamber 46a through the suction hole <NUM>, and the gas refrigerant previously suctioned from the suction hole <NUM> is compressed in the compression chamber 46b. In the compressed gas refrigerant, the gas refrigerant discharged into the muffler <NUM> through the main bearing discharge hole <NUM> is discharged into the case <NUM> through the communication hole <NUM> of the muffler <NUM>. On the other hand, in the compressed gas refrigerant, the gas refrigerant discharged into the balancer cover <NUM> through the auxiliary bearing discharge hole <NUM> flows into the muffler <NUM> through the communication hole <NUM>, and thereafter, is discharged into the case <NUM> through the communication hole <NUM> of the muffler <NUM>. The gas refrigerant discharged into the case <NUM> is fed to the condenser <NUM> as described above.

Incidentally, a pressure equivalent to a discharge pressure of the gas refrigerant acts on the lubricating oil J inside the case <NUM>. Therefore, the lubricating oil J flows into the main flow path <NUM>, and rises inside the main flow path <NUM> as the rotary shaft <NUM> is rotated. The lubricating oil J rising inside the main flow path <NUM> is distributed to each of the sub-flow paths <NUM> and <NUM> by the centrifugal force generated by the rotation of the rotary shaft <NUM>.

The lubricating oil J distributed to each of the sub-flow paths <NUM> and <NUM> is discharged on the outer peripheral surface of the rotary shaft <NUM> and is supplied to each sliding portion. For example, the lubricating oil J discharged from the first sub-flow path <NUM> rises inside the upper circulation path as the rotary shaft <NUM> is rotated and is supplied to a portion between the main shaft portion <NUM> and the main bearing <NUM>. On the other hand, the lubricating oil J discharged from the second sub-flow path <NUM> rises inside the lower circulation path <NUM> as the rotary shaft <NUM> is rotated and is supplied to a portion between the auxiliary shaft portion <NUM> and the auxiliary bearing <NUM> and a portion between the eccentric portion <NUM> and the roller <NUM>. The lubricating oil J supplied to each sliding portion is discharged from the compression mechanism <NUM> through a portion between the main shaft portion <NUM> and the main bearing <NUM> and through the cylinder chamber <NUM>.

Here, the present embodiment adopts a configuration as follows. The thrust sliding portion <NUM> of the rotary shaft <NUM> and the seal <NUM> of the balancer cover <NUM> are brought into contact with each other to seal a portion in the axial direction between the rotary shaft <NUM> and the balancer cover <NUM>.

According to this configuration, the portion in the axial direction between the rotary shaft <NUM> and the balancer cover <NUM> is sealed by the seal <NUM>. Accordingly, it is possible to suppress a possibility that the lubricating oil J accommodated inside the case <NUM> may enter the inside of the balancer cover <NUM>. The possibility that the lubricating oil J may enter the inside of the balancer cover <NUM> is suppressed. Accordingly, even when the balancer <NUM> is provided in the auxiliary shaft portion <NUM>, it is possible to suppress a possibility that the eccentric rotation of the balancer <NUM> may be hindered by the lubricating oil J when the rotary shaft <NUM> is rotated. In this manner, rotational resistance acting on the balancer <NUM> can be reduced when the rotary shaft <NUM> is rotated. As a result, the rotary shaft <NUM> can efficiently be rotated, and compression performance can be improved.

Incidentally, in the rotary compressor <NUM>, when the rotary shaft <NUM> is displaced upward due to vibration caused by the eccentric rotation, the thrust sliding portion <NUM> and the seal <NUM> may be separated from each other in some cases. In this case, there is a possibility that the gas refrigerant discharged into the balancer cover <NUM> through the auxiliary bearing discharge hole <NUM> may leak outward of the balancer cover <NUM> through the through-hole <NUM>.

Therefore, the present embodiment adopts a configuration as follows. The protruding portion <NUM> protrudes downward from the lower end opening edge of the through-hole <NUM> of the balancer cover <NUM> more than the predetermined distance which is the displacement amount of the rotary shaft <NUM>.

According to this configuration, when the gas refrigerant discharged into the balancer cover <NUM> leaks outward of the balancer cover <NUM> through the through-hole <NUM>, it is possible to suppress a possibility that the gas refrigerant may flow into the main flow path <NUM> after turning around the protruding portion <NUM>. In this manner, it is possible to suppress a possibility that the gas refrigerant may flow into the supply channel <NUM> and the lubricating oil J may not spread to the sliding portion. That is, in the rotary compressor <NUM> according to the present embodiment, the lubricating oil J can effectively be supplied to the sliding portion, and the desired lubrication performance can be obtained.

The refrigeration cycle apparatus <NUM> according to the present embodiment includes the above-described rotary compressor <NUM>. Accordingly, it is possible to provide the refrigeration cycle apparatus <NUM> capable of improving operation reliability and compression performance over a long period of time.

<FIG> is a partial sectional view of a rotary compressor <NUM> according to a second embodiment. In the following description, the same reference numerals will be assigned to configurations the same as those of the above-described embodiment, and description thereof will be omitted.

The rotary compressor <NUM> according to the present embodiment is different from the above-described first embodiment in that a plurality of (for example, three) cylinders (upper cylinder <NUM>, intermediate cylinder <NUM>, and lower cylinder <NUM>) are aligned in the axial direction.

In the rotary compressor <NUM> shown in <FIG>, the upper cylinder <NUM> and the intermediate cylinder <NUM> abut each other in the axial direction while an upper partitioning portion <NUM> is interposed therebetween. The intermediate cylinder <NUM> and the lower cylinder <NUM> abut each other in the axial direction while a lower partitioning portion <NUM> is interposed therebetween. A configuration of each of the cylinders <NUM> to <NUM> is the same as that of the above-described embodiment. The upper cylinder <NUM>, the lower cylinder <NUM>, the main bearing <NUM>, the auxiliary bearing <NUM>, and the partitioning portions <NUM> and <NUM> form a compression mechanism <NUM> according to the present embodiment.

An upper end opening portion of the upper cylinder <NUM> is closed by the main bearing <NUM>. A space defined by the upper cylinder <NUM>, the main bearing <NUM>, and the upper partitioning portion <NUM> forms an upper cylinder chamber <NUM>.

A space defined by the intermediate cylinder <NUM> and the partitioning portions <NUM> and <NUM> forms an intermediate cylinder chamber <NUM>.

A lower end opening portion of the lower cylinder <NUM> is closed by the auxiliary bearing <NUM>. A space defined by the lower cylinder <NUM>, the auxiliary bearing <NUM>, and the lower partitioning portion <NUM> forms a lower cylinder chamber <NUM>.

The rotary shaft <NUM> includes a base shaft portion <NUM> provided with the thrust sliding portion <NUM>, and a supplementary shaft portion <NUM> fixed to the base shaft portion <NUM> and forming a protruding portion <NUM>.

The base shaft portion <NUM> includes a plurality of eccentric portions <NUM> to <NUM> accommodated in the respective cylinder chambers <NUM> to <NUM>. Specifically, the upper eccentric portion <NUM> is formed in a portion located inside the upper cylinder chamber <NUM> in the base shaft portion <NUM>. The intermediate eccentric portion <NUM> is formed in a portion located inside the intermediate cylinder chamber <NUM> in the base shaft portion <NUM>. The lower eccentric portion <NUM> is formed in a portion located inside the lower cylinder chamber <NUM> in the base shaft portion <NUM>. Each of the eccentric portions <NUM> to <NUM> has the same outer shape and the same size when viewed in the axial direction. Each of the eccentric portions <NUM> to <NUM> is eccentric with respect to the axis line O by the same amount in the radial direction while having a phase difference of <NUM>° in the circumferential direction. That is, eccentric directions of the respective eccentric portions <NUM> to <NUM> are set to be equal to each other in the circumferential direction. A roller <NUM> is fitted to each of the eccentric portions <NUM> to <NUM>. The lower end surface of the base shaft portion <NUM> serves as the thrust sliding portion <NUM>.

A base flow path <NUM> is formed in the base shaft portion <NUM>. The base flow path <NUM> extends coaxially with the axis line O. A lower end portion of the base flow path <NUM> is open on a lower end surface (thrust sliding portion <NUM>) of the base shaft portion <NUM>. The base flow path <NUM> communicates with each of the sub-flow paths <NUM> and <NUM>. In the base shaft portion <NUM>, the sub-flow path may be provided at a position corresponding to each of the partitioning portions <NUM> and <NUM>.

The protruding portion <NUM> including the supplementary shaft portion <NUM> is formed in a cylindrical shape extending coaxially with the axis line O. That is, the inside of the protruding portion <NUM> forms a protruding portion flow path <NUM> that penetrates the protruding portion <NUM> in the axial direction. An upper end portion of the protruding portion <NUM> is fixed inside the base flow path <NUM> by means of press-fitting. That is, the protruding portion <NUM> is fixed to the base shaft portion <NUM> in a state where the protruding portion <NUM> protrudes downward from the thrust sliding portion <NUM>, and the base flow path <NUM> and the protruding portion flow path <NUM> communicate with each other. The base flow path <NUM> and the protruding portion flow path <NUM> form a main flow path <NUM> according to the present embodiment. A method of fixing the base shaft portion <NUM> of the protruding portion <NUM> may be any desired method other than the press-fitting.

A balancer cover <NUM> according to the present embodiment includes a cover body <NUM> that covers the auxiliary bearing <NUM> from below, and a thrust plate <NUM> attached to the cover body <NUM>. Even in the present embodiment, the inside of the balancer cover <NUM> communicates with the inside of the muffler <NUM> through a communication hole (not shown).

The cover body <NUM> is formed in a bottomed cylindrical shape. An upper end portion of the cover body <NUM> is attached to the flange portion <NUM> of the auxiliary bearing <NUM>. An accommodation hole <NUM> is formed in a bottom portion of the cover body <NUM>. The accommodation hole <NUM> penetrates the bottom portion of the cover body <NUM> in the axial direction. A lower end portion of the base shaft portion <NUM> is accommodated inside the accommodation hole <NUM>. In the illustrated example, it is preferable that the thrust sliding portion <NUM> and the bottom portion (lower surface) of the cover body <NUM> are disposed flush with each other.

The thrust plate <NUM> is formed in a disk shape having a diameter larger than that of the above-described accommodation hole <NUM>. The thrust plate <NUM> closes the accommodation hole <NUM> from below in a state where an outer peripheral portion is fixed to the bottom portion of the cover body <NUM> by a screw <NUM>. In the thrust plate <NUM>, a through-hole <NUM> is formed in a portion that overlaps the main flow path <NUM> of the rotary shaft <NUM> when viewed in the axial direction. The inner diameter of the through-hole <NUM> is smaller than the inner diameter of the accommodation hole <NUM> and is larger than the outer diameter of the protruding portion <NUM>. The above-described protruding portion <NUM> penetrates into the through-hole <NUM>. In this manner, a lower end opening portion of the main flow path <NUM> communicates with the inside of the case <NUM> below the balancer cover <NUM> (lower surface of the thrust plate <NUM>).

The above-described thrust sliding portion <NUM> is in contact with a portion (seal 242a) located around the through-hole <NUM> in the axial direction, on the upper surface of the thrust plate <NUM>. In this manner, communication between the inside of the balancer cover <NUM> and the inside of the case <NUM> is blocked.

In the present embodiment, a gap S1 in the radial direction between the inner peripheral surface of the accommodation hole <NUM> and the outer peripheral surface of the base shaft portion <NUM> is larger than a gap S2 in the radial direction between the inner peripheral surface of the through-hole <NUM> and the outer peripheral surface of the protruding portion <NUM>. The gaps S1 and S2 do may not be uniform in the entire circumferential direction due to dimensional variations. The gap S1 may be equal to or smaller than the gap S2.

Next, a method for manufacturing the rotary compressor <NUM> according to the present embodiment will be described. In the following description, an assembly process of assembling the thrust plate <NUM> to the cover body <NUM> in a state where the rotary shaft <NUM> and the cover body <NUM> are assembled will be described.

<FIG> is a process drawing for describing the assembly process.

As shown in <FIG>, the assembly process of the thrust plate <NUM> according to the present embodiment includes a positioning process and a fixing process.

In the positioning process, a jig <NUM> is used to position the thrust plate <NUM> with respect to the protruding portion <NUM>. Specifically, the jig <NUM> is formed in a cylindrical shape disposed coaxially with the axis line O. The jig <NUM> has an operation portion <NUM> located in a lower portion and a plate holding portion <NUM> located in an upper portion.

The outer diameter of the operation portion <NUM> is larger than the inner diameter of the through-hole <NUM>.

The plate holding portion <NUM> is connected to an upper side of the operation portion <NUM>. The plate holding portion <NUM> is formed in a tapered shape whose outer diameter gradually decreases upward. A minimum outer diameter of the plate holding portion <NUM> is smaller than the inner diameter of the through-hole <NUM>.

The inside of the jig <NUM> forms an insertion hole <NUM> into which the protruding portion <NUM> can be inserted. The jig <NUM> is not limited to a cylindrical shape as long as a configuration has a plate holding portion for holding the inner peripheral surface of the through-hole <NUM> and an accommodation portion capable of accommodating the protruding portion <NUM>.

In the positioning process, the plate holding portion <NUM> is inserted into the through-hole <NUM> of the thrust plate <NUM>. Then, a lower end opening edge of the through-hole <NUM> is held by the outer peripheral surface of the plate holding portion <NUM>. It is preferable that the plate holding portion <NUM> holds the thrust plate <NUM> in a state where the plate holding portion <NUM> does not protrude upward from the through-hole <NUM>.

Subsequently, the jig <NUM> is disposed coaxially with the axis line O below the rotary shaft <NUM> (cover body <NUM>), and the thrust plate <NUM> and the jig <NUM> are raised. Then, the thrust plate <NUM> moves close to the cover body <NUM> while the protruding portion <NUM> is inserted into the insertion hole <NUM> of the jig <NUM>. The thrust plate <NUM> is raised until the thrust plate <NUM> abuts the lower surface of the cover body <NUM>. In this manner, the size of the gap between the through-hole <NUM> of the thrust plate <NUM> and the outer peripheral surface of the protruding portion <NUM> becomes substantially uniform in the circumferential direction, and the thrust plate <NUM> is positioned in the radial direction with respect to the protruding portion <NUM>. The thrust plate <NUM> may be rotated in the circumferential direction with respect to the cover body <NUM> to align a fixing portion between the thrust plate <NUM> and the cover body <NUM>.

Next, in the fixing process, the thrust plate <NUM> is fixed to the cover body <NUM> by a screw <NUM> (refer to <FIG>). Thereafter, the jig <NUM> is retreated to complete the assembly process of the thrust plate <NUM>.

In the present embodiment, in addition to achieving operational effects the same as those of the above-described first embodiment, the following operational effects are achieved.

That is, in the present embodiment, the base shaft portion <NUM> and the protruding portion <NUM> (supplementary shaft portion <NUM>) are separately formed. In this manner, the rotary shaft does not need to be processed into a stepped shape as in a case where the base shaft portion and the protruding portion are integrally formed. Therefore, the accurate thrust sliding portion <NUM> can easily be manufactured, and it is possible to provide the low cost rotary compressor <NUM> having excellent manufacturing efficiency. Since the base shaft portion <NUM> and the protruding portion <NUM> are separately formed, an optimum material can be selected for each component. Therefore, design can more freely be selected.

Since the base shaft portion <NUM> and the protruding portion <NUM> are separate from each other, a shaft length of each component can be shortened, and each component can accurately and easily be formed.

The present embodiment adopts a configuration as follows. The gap S1 in the radial direction between the inner peripheral surface of the accommodation hole <NUM> and the outer peripheral surface of the base shaft portion <NUM> is larger than the gap S2 in the radial direction between the inner peripheral surface of the through-hole <NUM> and the outer peripheral surface of the protruding portion <NUM>. According to this configuration, since the gap S1 is enlarged, the lubricating oil J existing inside the balancer cover <NUM> can easily be accommodated inside the gap S1.

In this manner, the lubricating oil J is likely to be interposed between the outer peripheral surface of the base shaft portion <NUM> and the inner peripheral surface of the accommodation hole <NUM>, and between the thrust sliding portion <NUM> and the seal 242a. Therefore, it is possible to improve lubrication performance.

On the other hand, since the gap S2 is reduced, a contact area (seal area) is likely to increase between the thrust sliding portion <NUM> and the seal 242a. In this manner, sealing performance can be improved, and a surface pressure acting between the thrust sliding portion <NUM> and the seal 242a can be reduced.

Therefore, it is possible to provide the power-saving and high-quality rotary compressor <NUM> excellent in operation reliability over a long period of time. When the position of the rotary shaft <NUM> is displaced upward, it is possible to suppress a leakage amount when the gas refrigerant discharged into the balancer cover <NUM> leaks outward of the balancer cover <NUM> through the through-hole <NUM>.

The present embodiment adopts a configuration as follows. The jig <NUM> having the plate holding portion <NUM> for holding the inner peripheral surface of the through-hole <NUM> and the insertion hole <NUM> into which the protruding portion <NUM> is inserted is used so that the thrust plate <NUM> is positioned with respect to the protruding portion <NUM>.

According to this configuration, it is possible to suppress contact between the protruding portion <NUM> and the thrust plate <NUM>. Therefore, it is possible to suppress friction during the operation.

The gap S1 is enlarged as described above. In this manner, it is easy to avoid contact between the base shaft portion <NUM> having a large turning radius in the rotary shaft <NUM> and the cover body <NUM>. In this manner, it is also possible to suppress the friction during the operation.

As a result, it is possible to provide the power-saving and high-quality rotary compressor <NUM> excellent in operation reliability over a long period of time.

In the second embodiment, a configuration having three cylinders has been described. However, a configuration having a plurality of cylinders other than three may be adopted.

In the second embodiment, a configuration in which each of the rotary shaft <NUM> and the balancer cover <NUM> is separately formed has been described. However, any one of the rotary shaft <NUM> and the balancer cover <NUM> may separately be formed.

In the second embodiment, a configuration in which the thrust plate <NUM> is assembled in a state where the rotary shaft <NUM> and the cover body <NUM> are assembled has been described. However, the present invention is not limited only to this configuration. For example, the cover body <NUM> may be assembled to the auxiliary bearing <NUM> in a state where the cover body <NUM> and the thrust plate <NUM> are assembled in advance.

In the above-described embodiment, a configuration in which the roller <NUM> and the blade <NUM> are separate from each other has been described. However, the present invention is not limited only to this configuration. For example, a type in which the blade and the roller are integrated with each other may be adopted.

According to at least one of the above-described embodiments, desired lubrication performance can be obtained.

Claim 1:
A rotary compressor (<NUM>, <NUM>) comprising:
a case (<NUM>) configured to store a lubricating oil;
a rotary shaft (<NUM>, <NUM>) disposed inside the case (<NUM>), and having an eccentric portion (<NUM>, <NUM>, <NUM>, <NUM>);
a compression mechanism (<NUM>) having
a cylinder (<NUM>, <NUM>, <NUM>, <NUM>) accommodating the eccentric portion (<NUM>, <NUM>, <NUM>, <NUM>),
a main bearing (<NUM>) configured to rotatably support the rotary shaft (<NUM>, <NUM>) from above the cylinder (<NUM>, <NUM>, <NUM>, <NUM>), and
an auxiliary bearing (<NUM>) configured to rotatably support the rotary shaft (<NUM>, <NUM>) from below the cylinder (<NUM>, <NUM>, <NUM>, <NUM>);
a balancer (<NUM>) attached to the rotary shaft (<NUM>, <NUM>) at a position below the auxiliary bearing (<NUM>); and
a balancer cover (<NUM>, <NUM>, <NUM>) configured to cover the balancer (<NUM>) from below,
wherein a through-hole (<NUM>, <NUM>) is formed at a position of the balancer cover (<NUM>, <NUM>, <NUM>) facing the rotary shaft (<NUM>, <NUM>) in an axial direction, and
the rotary shaft (<NUM>, <NUM>) includes
a thrust sliding portion (<NUM>) configured to come into contact with a seal (<NUM>, 242a) located around the through-hole (<NUM>, <NUM>) of the balancer cover (<NUM>, <NUM>, <NUM>), in the axial direction, thereby blocking communication between the inside and the outside of the balancer cover (<NUM>, <NUM>, <NUM>) through the through-hole (<NUM>, <NUM>),
characterized in that the rotary shaft (<NUM>, <NUM>) further includes
a protruding portion (<NUM>, <NUM>) located on an inner peripheral side of the thrust sliding portion (<NUM>), and protruding downward from a lower end of the through-hole (<NUM>, <NUM>) through the through-hole (<NUM>, <NUM>), and
a supply channel (<NUM>) open on a lower end surface of the protruding portion (<NUM>, <NUM>) to guide the lubricating oil,
wherein the rotary shaft (<NUM>, <NUM>) is displaceable by a predetermined distance in the axial direction with respect to the compression mechanism (<NUM>), and
the protruding portion (<NUM>, <NUM>) protrudes from the lower end of the through-hole (<NUM>, <NUM>) to be longer than the predetermined distance.