Patent Description:
Heretofore, for example, an internal intermediate pressure multi-stage (two stages) compression rotary compressor comprising first and second rotary compression elements has been known.

Such a rotary compressor has a configuration including, in a sealed container, a drive motor and first and second rotary compression mechanisms that are driven with this drive motor. Refrigerant gas is taken into a low pressure chamber side of a cylinder through an intake port of the first rotary compression mechanism, and compressed by an operation of a roller and a vane to obtain an intermediate pressure, and the gas is discharged from a high pressure chamber side of the cylinder through a discharge port and a discharge muffler into the sealed container. The intermediate pressure refrigerant gas in this sealed container is taken into a low pressure chamber side of the cylinder through an intake port of the second rotary compression mechanism, and subjected to second stage compression by an operation of a roller and a vane. Resulting high-temperature high-pressure refrigerant gas is discharged from the high pressure chamber side to the outside. This technology is disclosed.

In the rotary compressor in which such two-stage compression is performed, a compressed refrigerant is discharged from a second stage compression chamber directly to the outside of the rotary compressor, and hence the refrigerant and oil cannot be separated. Consequently, a mainstream lies in a mechanism on which an oil separator is externally mounted and in which oil is returned in a system circuit.

Therefore, for example, a conventional technology is disclosed in which oil separation means for reducing discharge of oil to the outside of a sealed container by centrifugal separation is used, so that the oil can be separated in the rotary compressor (e.g., see Patent Literature <NUM>).

Patent Literature <NUM> relates to a so-called internal intermediate pressure multistage compression type rotary compressor making it possible to prevent the pressure inside a roller from inconveniently increasing and also to permit smooth and reliable supply of oil into a cylinder of a second rotary compressing element. A lubrication groove for providing communication between an oil bore and a low-pressure chamber in the cylinder is formed in a surface of an intermediate partitioner that is adjacent to the cylinder of the second rotary compressing element. Furthermore, a through bore for providing communication between a hermetically sealed vessel and the inside of the roller is formed in the intermediate partitioner.

Patent Literature <NUM> relates to a rotary compressor comprising an electric element, and first and second rotary compression elements driven by the electric element. These components are provided in a hermetically sealed container. Gas compressed by the first rotary compression element is discharged into the hermetically sealed container, and the discharged gas of intermediate pressure is further compressed by the second rotary compression element wherein cylinders constitute the respective rotary compression elements. An intermediate diaphragm is provided between the cylinders to partition each rotary compression element. A support member is adapted to seal an opening surface of each cylinder and is provided with a bearing of a rotary shaft and an oil hole formed in the rotary shaft wherein the intermediate diaphragm includes an oil supply path for communicating the oil hole with a suction side of the second rotary compression element.

In a technology of Patent Literature <NUM>, however, there is a problem that performance loss due to pressure bypass is generated in a process of returning oil separated in a rotary compressor. Generally, in the rotary compressor of a two-stage compression direct discharge specification, intermediate pressure oil in a sealed container is always supplied into compression chambers for improvement of sealability in a second stage compression chamber.

Therefore, there is a problem that an amount of oil to be discharged from the second stage compression chamber definitely increases. Furthermore, there is also a situation where it is difficult to decrease an amount of oil to be supplied to the second stage compression chamber due to manufacturing process constraint such as processing accuracy.

The present invention has been developed in view of the above described respects, and an object of the present invention is to provide a rotary compressor in which an amount of oil to be supplied through an oil supply hole can be properly adjusted with a simple configuration.

To achieve the above object, according to the present invention, provided is a rotary compressor as defined in claim <NUM> comprising, i. a sealed container, a drive motor, a first stage rotary compression mechanism and a second stage rotary compression mechanism that are rotated and driven by rotation of the drive motor, and an intermediate partition plate provided between the first stage rotary compression mechanism and the second stage rotary compression mechanism, wherein in the intermediate partition plate, an oil supply passage that extends from a center of the sealed container toward outside is provided, an oil supply hole that communicates between the oil supply passage and a second compression chamber of the second stage rotary compression mechanism is formed, and the oil supply hole is formed at a position to be opened where a second roller of the second stage rotary compression mechanism is at a position other than a compression stroke.

Consequently, the oil supply hole to be opened where the second roller is at the position other than the compression stroke is provided, and hence the oil supply hole can be held in an opened state or a closed state in accordance with a crank angle of the second roller. This makes it possible to adjust an amount of oil to be supplied through the oil supply hole.

According to the present invention, an oil supply hole is provided to be opened where a second roller is at a position other than a compression stroke, and hence the oil supply hole can be held in an opened state or a closed state in accordance with a crank angle of the second roller. This makes it possible to adjust an amount of oil to be supplied through the oil supply hole with a simple configuration.

According to the invention, a rotary compressor comprises, in a sealed container, a drive motor, a first stage rotary compression mechanism and a second stage rotary compression mechanism that are rotated and driven by rotation of the drive motor, and an intermediate partition plate provided between the first stage rotary compression mechanism and the second stage rotary compression mechanism, wherein in the intermediate partition plate, an oil supply passage that extends from a center of the sealed container toward outside is provided, an oil supply hole that communicates between the oil supply passage and a second compression chamber of the second stage rotary compression mechanism is formed, and the oil supply hole is formed at a position to be opened where a second roller of the second stage rotary compression mechanism is at a position other than a compression stroke.

Consequently, the oil supply hole to be opened where the second roller is at the position other than the compression stroke is provided, and hence the oil supply hole can be held in an opened state or a closed state in accordance with a crank angle of the second roller. This makes it possible to adjust an amount of oil to be supplied through the oil supply hole with a simple configuration.

In an example, the oil supply hole is provided in a range from <NUM>° to <NUM>° on a suction passage side from a position of a second vane of the second stage rotary compression mechanism so that the oil supply hole communicates at a crank angle of the second roller in a range from <NUM>° to <NUM>°.

Consequently, the oil supply hole is provided in the range from <NUM>° to <NUM>° on the suction passage side from the position of the second vane of the second stage rotary compression mechanism so that the oil supply hole communicates at the crank angle of the second roller in the range from <NUM>° to <NUM>°. Therefore, when the second roller is at the position other than the compression stroke, the oil supply hole can be opened. This makes it possible to adjust the amount of the oil to be supplied through the oil supply hole.

Hereinafter, description will be made as to an embodiment of the present invention with reference to the drawings.

<FIG> is a schematic vertical cross-sectional view showing the embodiment of a rotary compressor of the present invention. <FIG> is an enlarged view of the rotary compressor.

As shown in <FIG> and <FIG>, a rotary compressor <NUM> comprises a vertical cylindrical sealed container <NUM> made of a steel plate, and a lid body <NUM> is attached to an upper part of the sealed container <NUM>. In an upper part of an interior of the sealed container <NUM>, a drive motor <NUM> is contained.

A terminal <NUM> is attached to a center of an upper surface of the lid body <NUM>, to supply power to the drive motor <NUM>.

The drive motor <NUM> comprises an annular stator <NUM> attached along an inner peripheral surface of an upper space of the sealed container <NUM>, and a rotor <NUM> inserted and disposed inside the stator <NUM> with a gap. A rotary shaft <NUM> that extends in an axial direction of the sealed container <NUM> is attached to a center of the rotor <NUM>.

The stator <NUM> comprises a laminate body <NUM> made of laminated annular electromagnetic steel plates, and a stator coil <NUM> wound around the laminate body <NUM>. Furthermore, the rotor <NUM> comprises a laminate body <NUM> made of laminated electromagnetic steel plates, and a permanent magnet <NUM> disposed in the laminate body <NUM>.

In a lower part of the interior of the sealed container <NUM>, a first stage rotary compression mechanism <NUM> rotated and driven by the rotary shaft <NUM> of the drive motor <NUM> and a second stage rotary compression mechanism <NUM> located on an upper side are arranged. An intermediate partition plate <NUM> is disposed between the first stage rotary compression mechanism <NUM> and the second stage rotary compression mechanism <NUM>.

An upper support member <NUM> that closes an upper surface opening of the second stage rotary compression mechanism <NUM> is disposed above the second stage rotary compression mechanism <NUM>, and a lower support member <NUM> that closes a lower surface opening of the first stage rotary compression mechanism <NUM> is disposed below the first stage rotary compression mechanism <NUM>.

The first stage rotary compression mechanism <NUM> comprises a first cylinder <NUM> including a first compression chamber <NUM> to compress a refrigerant therein, a first eccentric member <NUM> provided in the first cylinder <NUM>, a first roller <NUM> fitted in the first eccentric member <NUM> to be eccentrically rotated, and a first vane that abuts on an outer peripheral surface of the first roller <NUM> to divide the first compression chamber <NUM> in the first cylinder <NUM> into a low pressure chamber side and a high pressure chamber side.

Similarly, the second stage rotary compression mechanism <NUM> comprises a second cylinder <NUM> including a second compression chamber <NUM> to compress the refrigerant therein, a second eccentric member <NUM> provided in the second cylinder <NUM>, a second roller <NUM> fitted in the second eccentric member <NUM> to be eccentrically rotated, and a second vane <NUM> that abuts on an outer peripheral surface of the second roller <NUM> to divide the second compression chamber <NUM> in the second cylinder <NUM> into a low pressure chamber side and a high pressure chamber side.

In the upper support member <NUM> and the lower support member <NUM>, a suction passage (not shown) that communicates with interiors of the second cylinder <NUM> and first cylinder <NUM> in an unshown suction port is provided, and an upper cover <NUM> and a lower cover <NUM> are provided on an upper surface of the upper support member <NUM> and a lower surface of the lower support member <NUM>, respectively. In the lower surface of the lower support member <NUM>, an intermediate pressure first stage discharge muffler <NUM>, partially formed in a recess shape, is provided. Furthermore, in the upper surface of the upper support member <NUM>, a high pressure second stage discharge muffler <NUM>, partially formed in a recess shape, is provided.

Furthermore, in the second stage rotary compression mechanism <NUM>, a suction passage <NUM> is provided to communicate from the second compression chamber <NUM> to the interior of the sealed container <NUM>.

Additionally, in the intermediate partition plate <NUM>, an oil supply passage <NUM> is formed to extend from a center of the sealed container <NUM> toward outside, and intermediate pressure oil is supplied to the oil supply passage <NUM>. In the oil supply passage <NUM>, an oil supply hole <NUM> is formed to be opened in the second compression chamber <NUM> of the second stage rotary compression mechanism <NUM>.

The oil supply hole <NUM> is formed at a position to be opened where the second roller <NUM> is at a position other than a compression stroke. Specifically, as an example that does not fall under the scope of the claim, when a position of the second vane <NUM> is set to <NUM>° so that the oil supply hole communicates at a crank angle of the second roller <NUM> in a range from <NUM>° to <NUM>°, the oil supply hole <NUM> is provided in a range from <NUM>° to <NUM>° on a suction passage <NUM> side from the second vane <NUM>. Furthermore, a distance of the oil supply hole <NUM> from a center of the rotary shaft <NUM> is also appropriately set.

Here, the oil supply hole <NUM> is formed at the position to be opened where the second roller <NUM> is at the position other than the compression stroke, because there is concern that the oil flows backward due to pressure of compression, if the oil supply hole <NUM> opens where the second roller <NUM> is at a position of the compression stroke.

Thus, the angle of the oil supply hole <NUM> from the second vane <NUM> and the distance of the hole from the center of the rotary shaft <NUM> are set, so that even in a case where an eccentric amount of the second roller <NUM> varies, it is possible to set a period in which the oil supply hole <NUM> is opened while the second roller <NUM> rotates once.

Note that in the present example, the oil supply hole <NUM> is provided in the range from <NUM>° to <NUM>° on the suction passage <NUM> side from the second vane <NUM>, but this is not restrictive. That is, the oil supply hole is provided from <NUM>° on the suction passage <NUM> side from the second vane <NUM>, because in consideration of a width dimension of the second vane <NUM>, the oil supply hole <NUM> cannot be formed at a position that overlaps with the second vane <NUM>. Consequently, the position of the oil supply hole <NUM> may be set to a range from <NUM>° to <NUM>° in accordance with the width dimension of the second vane <NUM>.

<FIG> is a view showing an example where the oil supply hole <NUM> is formed at a position having a distance of <NUM> from the center of the rotary shaft <NUM> and an angle of <NUM>° from the second vane <NUM>. <FIG> is a view showing an example where the oil supply hole <NUM> is formed at a position having a distance of <NUM> from the center of the rotary shaft <NUM> and an angle of <NUM>° from the second vane <NUM>.

As shown in <FIG>, in a case where the oil supply hole <NUM> is formed at the position having the distance of <NUM> from the center of the rotary shaft <NUM> and the angle of <NUM>° from the second vane <NUM> and in a case where the crank angle of the second roller <NUM> is <NUM>°, the oil supply hole <NUM> is closed. Even if the second roller <NUM> rotates to the crank angle of <NUM>°, the oil supply hole <NUM> is closed.

Then, when the crank angle of the second roller <NUM> reaches <NUM>°, the oil supply hole <NUM> starts opening, and when the crank angle of the second roller <NUM> is <NUM>°, the oil supply hole <NUM> finishes opening.

Furthermore, as shown in <FIG>, in a case where the oil supply hole <NUM> is formed at the position having the distance of <NUM> from the center of the rotary shaft <NUM> and the angle of <NUM>° from the second vane <NUM> and in a case where the crank angle of the second roller <NUM> is <NUM>°, the oil supply hole <NUM> is closed. Even when the second roller <NUM> rotates to the crank angle of <NUM>°, the oil supply hole <NUM> is closed, and when the crank angle of the second roller <NUM> is <NUM>°, the oil supply hole <NUM> starts opening. Then, when the crank angle of the second roller <NUM> is <NUM>°, the oil supply hole <NUM> finishes opening.

Next, an operation of the present embodiment will be described.

Upon driving of the drive motor <NUM>, the rotor <NUM> is rotated, and the rotary shaft <NUM> is rotated and driven, so that the first roller <NUM> and the second roller <NUM> are eccentrically rotated.

Consequently, low pressure refrigerant gas taken into the first cylinder <NUM> is compressed by an operation of the first roller <NUM> and the first vane to obtain an intermediate pressure, and is discharged from the first cylinder <NUM> into the sealed container <NUM>. In consequence, the gas obtains the intermediate pressure in the sealed container <NUM>.

Then, the intermediate pressure refrigerant gas in the sealed container <NUM> is taken into the second cylinder <NUM>, the taken intermediate pressure refrigerant gas is subjected to second stage compression by an operation of the second roller <NUM> and the second vane <NUM>, and the resulting high-temperature high-pressure refrigerant gas is discharged.

At this time, the oil mixed in the refrigerant gas flows into the oil supply passage <NUM> of the intermediate partition plate <NUM>, and flows through the oil supply hole <NUM> into the second cylinder <NUM>.

As described above, the oil supply hole <NUM> is held in the opened state or a closed state in accordance with the crank angle of the second roller <NUM>. Consequently, the oil supply hole <NUM> is not always opened, and hence an amount of oil to be supplied through the oil supply hole <NUM> can be properly adjusted.

As described above, in the present embodiment, the rotary compressor comprises, in the sealed container <NUM>, the drive motor <NUM>, the first stage rotary compression mechanism <NUM> and the second stage rotary compression mechanism <NUM> that are rotated and driven by rotation of the drive motor <NUM>, and the intermediate partition plate <NUM> provided between the first stage rotary compression mechanism <NUM> and the second stage rotary compression mechanism <NUM>, wherein in the intermediate partition plate <NUM>, the oil supply passage <NUM> that extends from the center of the sealed container <NUM> toward outside is provided, the oil supply hole <NUM> that communicates between the oil supply passage <NUM> and the second compression chamber <NUM> of the second stage rotary compression mechanism <NUM> is formed, and the oil supply hole <NUM> is formed at the position to be opened where the second roller <NUM> of the second stage rotary compression mechanism <NUM> is at the position other than the compression stroke.

Consequently, the oil supply hole <NUM> to be opened where the second roller <NUM> is at the position other than the compression stroke is provided, and hence the oil supply hole <NUM> can be held in the opened state or the closed state in accordance with the crank angle of the second roller <NUM>. This makes it possible to adjust the amount of the oil to be supplied through the oil supply hole <NUM>.

Furthermore, in an example, the oil supply hole <NUM> is provided in a range from <NUM>° to <NUM>° on a suction passage <NUM> side from a position of the second vane <NUM> of the second stage rotary compression mechanism <NUM> so that the oil supply hole communicates at the crank angle of the second roller <NUM> in a range from <NUM>° to <NUM>°.

Consequently, the oil supply hole <NUM> is provided in the range from <NUM>° to <NUM>° on the suction passage <NUM> side from the position of the second vane <NUM> of the second stage rotary compression mechanism <NUM> so that the oil supply hole communicates at the crank angle of the second roller <NUM> in the range from <NUM>° to <NUM>°. Therefore, when the second roller <NUM> is at the position other than the compression stroke, the oil supply hole <NUM> can be opened. This makes it possible to adjust the amount of the oil to be supplied through the oil supply hole <NUM>.

Note that the embodiment of the present invention has been described with reference to the drawings, but the present invention is not limited to the above embodiment, and can be modified without departing from the scope of the invention.

Claim 1:
A rotary compressor comprising
a sealed container (<NUM>),
a drive motor (<NUM>),
a first stage rotary compression mechanism (<NUM>) having a first roller (<NUM>) and a first vane (<NUM>), and
a second stage rotary compression mechanism (<NUM>) having a second roller (<NUM>) and a second vane (<NUM>), that are rotated and driven by rotation of the drive motor, and
an intermediate partition plate (<NUM>) provided between the first stage rotary compression mechanism and the second stage rotary compression mechanism,
wherein in the intermediate partition plate, an oil supply (<NUM>) passage that extends from a center of the sealed container toward outside is provided, an oil supply hole (<NUM>) that communicates between the oil supply passage and a second compression chamber (<NUM>) of the second stage rotary compression mechanism is formed,
the oil supply hole (<NUM>) is formed at a position to be opened where the second roller (<NUM>) of the second stage rotary compression mechanism (<NUM>) is at a position other than a compression stroke,
characterized in that
the oil supply hole (<NUM>) is provided at a position of <NUM>° on a suction passage side from a position of the second vane (<NUM>) of the second stage rotary compression mechanism (<NUM>) so that the oil supply hole (<NUM>) communicates at a crank angle of the second roller (<NUM>) in a range from <NUM>° to <NUM>°.