Hitachi, Ltd.

Hatachi Ltd

Shimizu Engineering Co., Ltd.

Hiroaki Kuno

Naoshi Uchikawa

Akira Murayama

Takao Mizuno

Takahiro Tamura

Masao Shiibayashi

Tetsuya Arata

Sumihisa Kotani

Kiyoshi Fukatsu

Kazutaka Suefuji

Eiichi Hazaki

Shigekazu Nozawa

Katsuaki Kikuchi

Hiroshi Takagi

Masayuki Urashin

Yoshikatsu Tomita

Yasushi Izunaga

Jyoji Okamoto

Kazumi Aiba

Yasuro Ohishi

Shintaro Sado

Atushi Amata

Hiroyuki Imamura

Mitsuhiko Miyagawa

Ryoichi Kuroshima

Mitsuo Ikeda

Masao Shibayashi

Minoru Tomono

A capacity controllable compressor apparatus has a plurality of high-pressure chamber compressors which are connected in parallel to a common refrigerant suction pipe and a common refrigerant discharge pipe, and oil equalizing pipes through which oil sumps of the plurality of compressors are communicated with each other. One of the plurality of compressors is operated with its chamber kept at a higher internal pressure than other compressors. The compressor apparatus comprises an oil separator disposed to the common discharge pipe; device for returning lubricating oil separated by the oil separator to a suction side of one of the compressors operated with its chamber kept at a higher internal pressure; first control device disposed in the oil equalizing pipes so as to prevent the lubricating oil from flowing into one of the two compressors communicated with each other by the oil equalizing pipe, said one being made inoperative when the capacity of the compressor apparatus is controlled; and valve device disposed in a discharge pipe of the inoperative compressor so as to prevent refrigerant from flowing into the inoperative compressor.

Capacity controllable compressor apparatus

An air conditioner provided with a refrigerant circuit formed by connecting with piping a refrigerant compressor, a condenser, an expansion means and an evaporator, an inverter power supply means for controlling the rotational speed of an electric motor for driving the refrigerant compressor, a load detector, and a controller for controlling the inverter power supply means on the basis of an output from the load detector. A refrigerant flow passage controlling mechanism is provided to change the rate at which the refrigerant flows through the condenser on the basis of a control command from the controller, thereby making it possible to reduce or increase the discharge rate without extending the range of changes in the rotational speed of the compressor. The compressor can be controlled according to a wide range of changes in the load to operate with an operation range which ensures high efficiency of the compressor operation.

Capacity-controllable air conditioner

In a scroll compressor, an open end of an oil extraction pipe which is placed in oil stored in a bottom portion of a hermetic casing is positioned at a location higher than an open end of an oil suction pipe that opens in the same stored oil, and a thermostat is provided for sensing a temperature rise of a compressed gas to cause the compressor to be stopped. Accordingly, even when an amount of oil injected into the compressed gas decreases, an amount of oil necessary for lubrication of a bearing portion is assured. The provision of the thermostat enables the compressor to be stopped before an amount of supply of the lubrication oil to the bearing portion has decreased. It is, accordingly, possible to positively prevent burning of the bearing portion of a crankshaft.

Mechanism for prevention of burning of bearing portions in a hermetic

A scroll compressor is provided with a two groups of commmunication ports formed in and extending through an end plate of a stationary scroll member. Each group includes two or more communication ports. A lead valve is associated with each of the two groups of communication ports and is operable by a pressure differential in between an associated compression chamber and the discharge chamber to communicate the communication ports of the group to the discharge chamber to prevent the occurrence of over-compression in the compression chamber.

Scroll compressor with valved port for each compression chamber

A sealed scroll compressor comprises a scroll compressor section, an electric motor, a sealed container, an oil storage, a fixed and orbiting scroll members, and a wire mesh member for improvement of oil separation in refrigerant gas. A shell portion of said sealed container is lined annularly with the wire mesh member and the gas containing oil is adapted to flow downwardly along the wire mesh member. When the gas flows downwardly, the oil sticks to the wire mesh member and is separated from the gas. The oil collected on the wire mesh member drops down into the oil storage. The gas from which the oil is separated is, after that, discharged out of the compressor.

Sealed type scroll compressor with wire mesh oil separating member

A scroll-type fluid machine for an air conditioning machine comprises a hermetically closed vessel which houses therein an orbiting scroll member and a stationary scroll member forming together a compressor portion, an Oldham ring member for preventing the orbiting scroll member from rotating about its own axis, a driving motor having a driving shaft connected to the orbiting scroll member for driving the same, and a frame for supporting the shaft, a low pressure liquid introducing passage for making the interior of the hermetically closed vessel a low pressure chamber, and a high pressure fluid discharge passage. A sealing member is provided at the back of the orbiting scroll member with its surfaces slidably contacting the frame and the orbiting scroll member to form a chamber separated from the low pressure chamber. A fluid which is in mid course of being compressed and has an intermediate pressure between suction pressure and discharge pressure is introduced into the separated chamber to maintain the same at the intermediate pressure, thereby overcoming a thrust force exerted on the orbiting scroll member to press the same against the stationary scroll member and effecting a proper supply of lubricating oil to moving portions of the machine.

Scroll-type fluid machine with seal to aid lubrication

A scroll-type fluid machine includes an orbiting scroll member and a stationary scroll member each of which has an end plate and a spiral wrap protruding upright therefrom. The scroll members are assembled together such that their wraps mesh with each other. Closed spaces are defined by the wraps and end plates of both scroll members, and are progressively moved towards the center of the scroll members while decreasing their volumes in accordance with an orbiting movement of the orbiting scroll member. The edges of the projecting end of the wrap of each scroll member are chamfered. Also, steps are formed in conformity with the configuration of each spiral wrap on respective corners of the groove bottom between adjacent turns of the wrap. The chamfered edges of the projecting end of the wrap of each scroll member faces the steps on the groove bottom of the opposing scroll member, respectively, when the scroll members are assembled together.

Scroll-type fluid machine with configured wrap edges and grooves

A scroll compressor including a stationary scroll and an orbiting scroll, with an intermediate pressure chamber being defined on a back side of the orbiting scroll member and being in communication with a pressure chamber through a communication hole to produce a force for pressing the orbiting scroll against the stationary scroll. Oil in an oil sink is supplied to sliding portions by a differential pressure between a pressure in the air tight container and a pressure in the intermediate pressure chamber. A valve is provided for switching the connection of the intermediate pressure chamber to a higher intermediate pressure side or to a lower intermediate pressure side of the compressor. The valve is constructed such that the intermediate pressure chamber is connected to the lower intermediate pressure side of the compressor when a discharge pressure of the compressor is lower than a certain value and connected to the higher intermediate pressure side of the compressor when the discharge pressure is higher than a certain value so that a proper oil supply pressure is maintained over a wide operational range.

Scroll compressor with pressure differential maintained for supplying oil

A scroll fluid apparatus including a fixed scroll member and an orbiting scroll member each having an end plate and a wrap, the two scroll members being maintained in meshing engagement with each other with the respective wraps facing inwardly to allow the orbiting scroll member to move in orbiting movement with respect to the fixed scroll member without rotating on its own axis. The fixed scroll member is formed with a discharge port at its central portion and a suction port at its outer peripheral surface to draw a gas by suction through the suction port and allow same to flow in a sealed space defined between the two scroll members and reducing its space during operation to thereby compress the gas and discharge the compressed gas through the discharge port. A clearance is defined between an outer peripheral surface of the end plate of the orbiting scroll member and a wall facing the outer peripheral surface and successively changing its volume as the orbiting scroll member moves in orbiting movement, and at least one pressure relieving space is provided to communicate with the clearance for conveniently discharging a fluid from the clearance to avoid compression of the fluid.

Scroll fluid apparatus

Disclosed is a scroll-type fluid machine which has an orbiting scroll member and a stationary scroll member each having an end plate and a spiral wrap protruding upright therefrom. The scroll members are assembled together such that their wraps mesh with each other to form therebetween closed chambers of volumes which are progressively decreased as the chambers are moved toward the centers of the scroll members as a result of an orbital movement of the orbiting scroll member with respect to the stationary scroll member. The machine is suitable for use as a refrigerant compressor in a refrigeration system. A fluid check valve is disposed in the refrigerant gas suction passage connected to the suction side of the machine, so as to prevent any reversing of the orbiting scroll member. A passage is formed to provide a communication between a suction chamber defined by the scroll members and another closed chamber. A relief valve is disposed in this communication passage so as to relief any abnormal high pressure from the suction chamber.

Scroll device with suction chamber pressure relief

A scroll-type fluid machine having an orbiting scroll member and a stationary scroll member each having an end plate and a spiral wrap of at least two turns protruding upright from one of the sides of the end plates. The orbiting scroll member has a back pressure chamber formed on the back side thereof and communicating with the compression spaces of the fluid machine through pressure equalizing ports formed in the orbiting scroll member, so that the pressure of the fluid under compression is introduced to the back pressure chamber to produce an axial thrusting force for pressing the orbiting scroll member towards the stationary scroll member. The positions of the pressure equalizing ports in terms of the wrap angle .lambda. of the wraps are selected to meet the following condition:

Scroll-type fluid machine with back pressure chamber biasing an orbiting

In a sealed type scroll compressor including an intermediate pressure chamber in which a pressure intermediate in magnitude between a discharge pressure and a suction pressure prevails, a bearing device including a roller bearing and a plain bearing mounted on a frame for supporting a shaft section of a crankshaft. To reduce application of unsymmetrical load to the bearings and prevent an increase in a bearing friction loss, the roller bearing is located in a position close to a crank section of the crankshaft and the plain bearing is located in a position remote from the crank section.

Bearing device of sealed type scroll compressor

A scroll-type compressor has an orbital scroll member and a stationary scroll member each having a disc-shaped end plate and a spiral wrap protruding upright from the end plate. The scroll members are assembled together with their wraps meshing with each other to define compression chambers therebetween. The orbital scroll member executes an orbital movement without rotating around its own axis. A discharge port and a suction port are formed in a central portion and a peripheral portion of the end plate of the stationary scroll member, respectively. As the orbital scroll member makes the orbital movement, the compression chambers are moved towards the center while decreasing their volumes thereby to progressively compress a gas drawn through the suction port and to discharge the compressed gas through the discharge port. The compressor further has a check valve disposed in a gas passage which is formed through the thickness of the end plate of the stationary scroll member so as to communicate with a suction chamber formed between the scroll members.

Scroll-type compressor

About 1 to about 25% by weight of a liquid refrigerant is mixed into a refrigerant gas to be introduced into a screw compressor by suction on the basis of the refrigerant gas in a refrigerator comprising a screw compressor, a condenser, and an expansion valve and an evaporator connected to one another in series. A cooling effect as well as a sealing effect can be satisfactorily attained thereby.

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Shimizu, Japan

Hiroaki Kuno