JP2008008165A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compressor having an expansion mechanism part with a little heat transfer loss. <P>SOLUTION: An oil pump 55 is provided between the expansion mechanism part 200 and a compression mechanism part 100. An oil supply channel 53 leading oil from an oil pocket 51 in a hermetic vessel 1 to the oil pump 55 and a suction opening part 52 thereof are arranged at surfaces upper than the expansion mechanism part 200. Consequently, oil around the expansion mechanism part 200 resides and the expansion mechanism part 200 is always soaked in low temperature oil. As a result, the oil is not replaced with oil after lubrication of the compression mechanism part 100 and the motor part 300, and heat transfer can be reduced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a compressor having both an expansion mechanism part and a compression mechanism part in one sealed container.

  Currently, the use of carbon dioxide as the working fluid of the refrigeration apparatus is being studied, but from the viewpoint of energy efficiency, the use of an expander as the expansion apparatus is being studied. Since the expansion mechanism part and the compression mechanism part are common in structure, the structure conventionally used as the compression mechanism part can be used as the expansion mechanism part (see, for example, Patent Document 1).

FIG. 2 shows a conventional compressor described in Patent Document 1. The expansion mechanism unit 501 and the compression mechanism unit 502 are housed in a sealed container 510, and the shafts of the mechanism units are connected to realize integration of the compressor and the expander. An oil pump 505 is provided on one of the shafts of the expansion mechanism portion 501 and the compression mechanism portion 502, and after sucking up oil from the oil reservoir 506 in the sealed container 510 and lubricating each sliding portion, again, The configuration returns to the oil reservoir 506.
JP-A-9-126171

  However, in the conventional configuration, heat transfer occurs between the expansion mechanism portion and the compression mechanism portion due to the oil in the oil reservoir. Since the compression mechanism unit compresses the working fluid, the temperature of the members constituting the compression mechanism unit increases with the compression operation of the working fluid. On the other hand, since the expansion mechanism section expands the working fluid, the temperature of the members constituting the expansion mechanism section decreases with the expansion operation of the working fluid. Accordingly, when the compression mechanism and the expansion mechanism are simply integrated and a common oil reservoir is provided in the sealed container, the oil always flows, so that the heat of the compression mechanism moves to the expansion mechanism via the oil. As a result, the working fluid is heated in the expansion mechanism. As a result, there has been a problem that the efficiency of the refrigeration cycle is lowered.

  The present invention provides a compressor having an expansion mechanism portion and a compression mechanism portion, which simultaneously suppresses heat transfer between the expansion mechanism portion and the compression mechanism portion, and at the same time secures a lubrication path to achieve high performance and high reliability. It aims at providing the compressor which was compatible.

  In order to solve the above-mentioned conventional problems, the compressor of the present invention is a compressor composed of a sealed container that houses a compression mechanism part in the upper part in the vertical direction, an expansion mechanism part in the lower part, and an electric motor part in the center part, An oil pump is provided between the expansion mechanism portion and the compression mechanism portion, and an oil supply path for guiding oil from an oil reservoir in the hermetic container to the oil pump and its suction opening are arranged on the upper surface from the expansion mechanism portion.

  According to such a configuration, the oil sucked from the oil reservoir is heated by lubricating the expansion mechanism portion, the compression mechanism portion, and the electric motor portion, and returns to the oil reservoir, but the oil suction port is located above the expansion mechanism portion. Since it is located, it will suck in the hot oil that has returned. In other words, the oil around the expansion mechanism part stays and is always immersed in oil at a low temperature. As a result, the heat transfer can be reduced without replacing the oil after lubricating the compression mechanism and the electric motor.

  The compressor of the present invention suppresses the heat transfer from the compression mechanism to the expansion mechanism by suppressing the flow of oil in the oil reservoir while including the expansion mechanism and the compression mechanism in the sealed container. And high performance can be realized.

  According to the first aspect of the present invention, the compressor includes a compression mechanism portion in the upper part in the vertical direction, an expansion mechanism portion in the lower portion, and an airtight container that houses the electric motor portion in the central portion, the expansion mechanism portion and the compression mechanism portion. An oil pump is provided between them, and an oil supply path for guiding oil from the oil reservoir in the sealed container to the oil pump and its suction opening are arranged on the upper surface from the expansion mechanism. According to this configuration, the oil sucked from the oil reservoir is heated by lubricating the expansion mechanism portion, the compression mechanism portion, and the electric motor portion, and returns to the oil reservoir, but the oil suction port is located above the expansion mechanism portion. The hot oil that has returned has to be sucked in again. In other words, the oil around the expansion mechanism part stays and is always immersed in oil at a low temperature. As a result, the heat transfer can be reduced without replacing the oil after lubricating the compression mechanism and the electric motor.

  In the present invention described in claim 2, the oil pump described in claim 1 is a positive displacement oil pump such as a trochoid pump or a rotary piston pump. In addition, according to this configuration, not only can a stable oil be supplied at all times, but there is almost no oil agitation unlike a centrifugal type or the like. As a result, it can be sucked up without disturbing the temperature distribution in the sealed container, and the positive heat transfer through the oil can be suppressed.

  According to the third aspect of the present invention, a motor rotor is mounted on the first shaft that constitutes the compression mechanism portion according to the first or second aspect, and is supported by two or more bearing portions to constitute the expansion mechanism portion. The second shaft and the first shaft are connected by a joint. According to this configuration, the oil path can be provided inside the first shaft and the second shaft, and it is possible to lubricate the compression mechanism portion disposed in the upper portion of the sealed container through the shaft.

  In the present invention described in claim 4, in particular, as the expansion mechanism portion according to claims 1 to 3, an expansion chamber is formed between the fixed scroll and the orbiting scroll in which a spiral wrap rises from the end plate, When the orbiting scroll is swung along a circular orbit under the rotation restriction by the rotation restriction mechanism, the expansion chamber moves while changing the volume, and the scroll type performs suction and discharge. According to this configuration, unlike the rotary system using vanes, for example, there is no need to supply oil directly from the oil reservoir. That is, since the oil around the expansion mechanism part stays, the heating amount to the expansion mechanism part can be reduced.

  In the fifth aspect of the present invention, particularly in the compressor of the first to fourth aspects, the working fluid is a high-pressure refrigerant, for example, carbon dioxide. In this case, in particular, the temperature difference between the compression mechanism portion and the expansion mechanism portion increases, and the amount of heat that moves through the oil also increases, so that the effects of the present invention are remarkably exhibited and performance degradation can be prevented.

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

(Embodiment 1)
A compressor according to an embodiment of the present invention will be described below. FIG. 1 is a side sectional view of a compressor according to an embodiment of the present invention.

  First, the configuration will be described. As shown in FIG. 1, in the sealed container 1, a compression mechanism unit 100 is disposed in the upper part, an expansion mechanism part 200 is disposed in the lower part, and an electric motor part 300 is disposed in the central part. These are fixed to the sealed container 1 by welding or the like. A shaft is arranged at the center of each part, and the first shaft 11 is arranged in the compression mechanism unit 100 and the second shaft 21 is arranged in the expansion mechanism unit 200. In the present embodiment, the first shaft 11 and the second shaft 21 will be described as two shafts. When a crank portion or the like is required, it is necessary to divide the shaft as in the present embodiment and connect it with a joint or the like.

  An oil reservoir 51 is provided at the bottom of the sealed container 1. The oil accumulated in this portion is sucked up by the oil pump 55 and supplied to the sliding portions in the compression mechanism portion 100 and the expansion mechanism portion 200 for lubrication. The oil that has lubricated the sliding portion returns to the oil reservoir 51 again.

  Next, the operation will be described. This type of compressor constitutes a refrigeration cycle apparatus together with a radiator and an evaporator, and is used for applications such as air conditioning and hot water heaters. The working fluid is taken from the suction pipe 2 of the compression mechanism unit 100 into the compression mechanism unit 100, compressed, and then sent out from the discharge pipe 3 to an external radiator. The working fluid radiated by the radiator is taken from the suction pipe 4 of the expansion mechanism section 200 into the expansion mechanism section 200 and expanded, and then sent from the discharge pipe 5 to the evaporator. The working fluid evaporated in the evaporator is compressed again by the compression mechanism 100, and heat is transferred by this series of cycles.

  Regarding the internal operation of the compressor, a magnetic field is generated by passing a current through the winding of the stator 91 of the electric motor unit 300, and a rotational force is applied to the motor rotor 92 by the magnetic force. Since the motor rotor 92 is fixed to the first shaft 11 (or the second shaft 21), the first shaft 11 (or the second shaft 21) also rotates in synchronization with the rotation of the motor rotor 92. The first shaft 11 serves to drive the orbiting scroll 12 in the compression mechanism unit 100. The orbiting scroll 12 meshes with the fixed scroll 13 to form a plurality of compression chambers 14, and compresses by sucking the working fluid as the first shaft 11 rotates. When the working fluid reaches a predetermined pressure, it passes through the discharge valve 15 and is sent out of the compression mechanism 100. Thereafter, the working fluid is forcibly guided downward by the muffler 16 and reaches the lower end of the electric motor unit 300 through the motor rotor 92. The working fluid is turned back here, proceeds to the upper part through the outer peripheral notch portion of the stator 91, and is sent out from the discharge pipe 3 to the outside, for example, to a radiator. In the present embodiment, the scroll mechanism has been described as an example of the compression mechanism unit 100, but the present invention is not limited to this.

The working fluid radiated by the radiator flows into the expansion chamber 24 from the suction pipe 4 of the expansion mechanism unit 200. As the working fluid expands, the enthalpy decreases and power is recovered. The recovered power is transmitted from the second shaft 21 to the first shaft 11 and used as part of the power of the compression mechanism unit 100.
The expanded working fluid is sent out from the discharge pipe 5 to the outside, for example, to the evaporator.

  As described above, since the compressor of the present invention includes the expansion mechanism unit 200, low power consumption can be achieved. However, there is a problem in making the compression mechanism unit 100 and the expansion mechanism unit 200 coexist in the same sealed container. One of these is the transfer of heat.

The heat transfer of the above problem will be described. Since the compression mechanism 100 performs compression, the working fluid becomes high temperature. On the other hand, since the working fluid that has passed through the radiator enters the expansion mechanism 200 and further expands, the working fluid has a low temperature. These perform heat exchange in the sealed container 1 and cause performance deterioration of the refrigeration cycle. The main factor of this heat exchange is the oil in the sealed container 1. Since the oil itself is at a high temperature, the point is how heat is not exchanged between the oil and the expansion mechanism 200.

  Therefore, an oil pump 55 is provided between the expansion mechanism unit 200 and the compression mechanism unit 100, and the oil supply path 53 for guiding oil from the oil reservoir 51 in the sealed container 1 to the oil pump 55 and its suction opening 52 are connected to the expansion mechanism unit. It is arranged on the upper surface from 200. As a result, the oil sucked from the oil reservoir is heated by lubricating the expansion mechanism unit 200, the compression mechanism unit 100, and the electric motor unit 300, and returns to the oil reservoir 51. However, the suction opening 52 is formed by the expansion mechanism unit 200. Since it is located on the upper surface, the hot oil that has returned is sucked again. That is, the oil around the expansion mechanism unit 200 stays and is always immersed in the oil having a low temperature. As a result, the heat transfer can be reduced without replacing the oil after lubricating the compression mechanism unit 100 and the electric motor unit 300.

  The oil pump 55 is preferably a positive displacement oil pump such as a trochoid pump or a rotary piston pump. If it is a positive displacement pump, it can not only always supply a stable oil, but unlike a centrifugal type etc., there is almost no oil agitation. As a result, it can be sucked up without disturbing the temperature distribution in the sealed container 1, and the positive heat transfer through the oil can be suppressed.

  The motor rotor 92 is preferably attached to the first shaft 11 constituting the compression mechanism unit 100, and the first shaft 11 is supported by two or more bearings and is connected to the second shaft 21 by a joint. In the present embodiment, the first shaft 11 is supported by the bearing 17 and the bearing 31, and the first shaft 11 and the second shaft 21 are splined and connected using a dedicated joint 32. . As a result, the oil path 56 can be provided inside the first shaft 11 and the second shaft 21, and the compression mechanism portion 100 disposed at the upper part of the hermetic container 1 can be lubricated through the shaft. .

  The expansion mechanism 200 is preferably a scroll method. Thus, unlike the rotary system using vanes, for example, there is no need to supply oil directly from the oil reservoir 51. That is, since the oil around the expansion mechanism unit 200 stays, the heating amount to the expansion mechanism unit 200 can be reduced.

  The working fluid can also be a high-pressure refrigerant, such as carbon dioxide. If the working fluid becomes a high-pressure refrigerant, the temperature difference between the compression mechanism unit 100 and the expansion mechanism unit 200 increases, and the amount of heat that moves through the oil also increases. Can be prevented.

  Since the compressor of the present embodiment includes an expansion mechanism portion, power recovery is possible and heat transfer between the compression mechanism portion and the expansion mechanism portion can be suppressed, so that a refrigeration cycle, particularly a hot water supply system is configured. It is particularly useful as a compressor.

Sectional drawing of the compressor in one Example of this invention Cross section of a conventional compressor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Airtight container 11 1st shaft 17 Bearing 21 2nd shaft 22 Orbiting scroll 23 Fixed scroll 24 Expansion chamber 28 Rotation restriction mechanism 31 Bearing 32 Joint 51 Oil reservoir 52 Suction opening 53 Oil supply path 55 Oil pump 100 Compression mechanism part 200 Expansion mechanism part 300 Electric motor part

Claims (5)

A compressor consisting of a compression mechanism part in the upper part in the vertical direction, an expansion mechanism part in the lower part, and a sealed container that houses the electric motor part in the center part,
An oil pump is provided between the expansion mechanism portion and the compression mechanism portion, and an oil supply path for guiding oil from the oil reservoir in the sealed container to the oil pump and its suction opening are arranged on the upper surface from the expansion mechanism portion. Compressor. The compressor according to claim 1, wherein the oil pump is a positive displacement oil pump such as a trochoid pump or a rotary piston pump. A motor rotor is attached to a first shaft that constitutes the compression mechanism portion, and is supported by two or more bearing portions, and the second shaft that constitutes the expansion mechanism portion and the first shaft are connected by a joint. The compressor according to claim 1 or 2. As the expansion mechanism portion, a fixed scroll and a turning scroll that rises from the end plate in a spiral shape are meshed to form an expansion chamber between the two, and the turning scroll is made into a circular orbit under the restriction of rotation by the rotation restriction mechanism. The compressor according to any one of claims 1 to 3, wherein the compressor is a scroll type that performs suction and discharge by moving the expansion chamber while changing its volume when swung along. The compressor according to any one of claims 1 to 4, wherein the working fluid is a high-pressure refrigerant, for example, carbon dioxide.

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