Rotary expansible chamber devices – Working member has planetary or planetating movement – Plural working members or chambers
Reexamination Certificate
2000-06-13
2001-12-25
Vrablik, John J. (Department: 3748)
Rotary expansible chamber devices
Working member has planetary or planetating movement
Plural working members or chambers
Reexamination Certificate
active
06332763
ABSTRACT:
TECHNICAL FIELD
The present invention relates to, for example, a pump, a compressor, an expander, etc., more specifically to a displacement type fluid machine.
BACKGROUND ART
As a conventional displacement type fluid machine, a reciprocating fluid machine for moving a working fluid by repeating a reciprocation of a piston in a cylindrical cylinder, a rotary (rolling piston type) fluid machine for moving the working fluid by eccentrically rotating a cylindrical piston in the cylindrical cylinder, a scroll fluid machine for moving the working fluid by engaging fixed scroll with an orbiting scroll having spiral wraps standing up on end plates and by gyrating the orbiting scroll are well known.
Since the reciprocating fluid machine is simply constructed, it is possible to prepare the machine easily and to be inexpensive. On the other hand, since a process from a suction completion to a discharge completion is short of shaft angle of 180° so that a flow velocity of the process for the discharge gets faster, there is a problem that a pressure loss is increased so that a performance is reduced. Further, since it is necessary to reciprocate the piston, so that a rotary shaft system can not be completely balanced, there is another problem that a vibration and a noise is larger.
Also, in the case of the rotary fluid machine, since the process from the suction completion to the pressure completion has the shaft angle of 360°, there is less problem that the pressure loss during the discharge process is increased compared to the reciprocating fluid machine. However, since the working fluid is discharged once per one rotation of the shaft, a variation of a gas compression torque is relatively higher, accordingly, there is the same problem of the vibration and noise as the reciprocating fluid machine.
Further, in the case of the scroll fluid machine, since the process from the suction completion to the discharge completion has the long shaft angle of 360° or more (the scroll fluid machine practically used as an air conditioner has usually 900°), so that the pressure loss during the process of the discharge is low, a plurality of working chambers are formed generally, so that there is an advantage that the variation of the gas compression torque is low and the vibration and noise is less. When the wraps are engaged, it is necessary to manage a clearance between the spiral wraps and the clearance between the end plate and a wrap tip. Thus, the fluid machine must be worked with high accuracy, so that there is further problem that the expense of working is expensive. Further, since the process from the suction completion to the discharge completion has the long shaft angle of 360° or more, it takes a long time for the compression process, so that there is further problem that an internal leakage is increased.
By the way, known is a displacement type fluid machine in which a displacer (a rotary piston) for moving the working fluid is not rotated relative to the cylinder in which the working fluid is suctioned, but is gyrated with an almost constant radius, that is, is gyrated to transmit the working fluid. This kind of displacement type fluid machines have been proposed in Japanese Patent Unexamined Publication No. 55-23353 (Document 1), U.S. Pat. No. 2,112,890 (Document 2), Japanese Patent Unexamined Publication No. 5-202869 (Document 3) and Japanese Patent Unexamined Publication No. 6-280758 (Document 4). These displacement type fluid machines comprise a petal-shaped piston having a plurality of members (vanes) radially extended from a center and a cylinder having a hollow portion having an almost the same shape as this piston, wherein this piston is gyrated in this cylinder in order to move the working fluid.
DISCLOSURE OF THE INVENTION
Since the displacement type fluid machines according to the Documents 1 to 4 do not have a portion for reciprocation of the reciprocating fluid machine, it is possible to balance the rotary shaft system completely. Thus, since the vibration is low, further a sliding velocity between the piston and the cylinder is low, the displacement type fluid machines are essentially provided with the advantageous characteristic that it is possible to reduce a friction loss.
However, the process from the suction completion to the discharge completion in each working chamber formed by the plurality of vanes constituting a piston and the cylinder has the short shaft angle &thgr;c of about 180° (210°) (about a half of that of the rotary fluid machine), the flow velocity during the discharge process gets faster, there is further problem that the pressure loss is increased, so that the performance is reduced. Also, in the fluid machines described in these Documents, the shaft angle from the suction completion to the discharge completion in each working chamber is short and a time lag is occurred from the suction completion to the next (compression) process (the suction completion) start and the working chamber from the suction completion to the discharge completion is one-sided around a drive shaft to be formed. Therefore, the fluid machines are not dynamically balanced and a rotating moment for prompting the piston itself to be rotated is excessively applied to the piston as a reaction from the compressed working fluid, thereby there is further problem of a reliability that the friction and abrasion of the vanes are occurred.
It is a first object of the present invention to provide a fluid machine which can reduce the fluid loss during the discharge process to the same extent of the scroll fluid machine and further can be more easily prepared than the scroll fluid machine.
It is a second object of the present invention to provide a more reliable displacement type fluid machine which can reduce the rotating moment to be applied to the rotary piston and solve the problem of the friction and abrasion.
It is a third object of the present invention to provide means for preparing the rotary piston inexpensively.
The first object is achieved by providing a displacement type fluid machine in which a displacer and a cylinder are located between end plates, one space is formed by an inner wall surface of said cylinder and an outer wall surface of said displacer when a center of said displacer is located on a center of rotation of a rotating shaft, and a plurality of spaces are formed when a positional relationship between said displacer and said cylinder is located on a center of gyration, wherein the curves of the inner wall surface of said cylinder and the outer wall surface of said displacer are formed so that a shaft angle &thgr;c of the process from the suction completion to the discharge completion in said plurality of spaces satisfies the following algorithm:
(((
N−
1)/
N·
360°)<&thgr;
c≦
360°,
where, N is the number of the extrusions extruded inwardly of said cylinder.
The second object is achieved by providing a displacement type fluid machine in which a displacer and a cylinder are located between end plates, one space is formed by an inner wall surface of said cylinder and an outer wall surface of said displacer when a center of said displacer is located on a center of rotation of a rotating shaft, and a plurality of spaces are formed when a positional relationship between said displacer and said cylinder is located on a center of gyration, wherein the curves of the inner wall surface of said cylinder and the outer wall surface of said displacer are formed so that a maximum value of the number of spaces in processes from a suction completion to a discharge completion in said plurality of spaces becomes more than the number of extrusions extruded inwardly of said cylinder.
The third object is achieved by providing a displacement type fluid machine comprising a cylinder having an inner wall whose section shape comprises a continuous curve, a displacer having an outer wall faced to the inner wall of said cylinder and forming a plurality of spaces by said inner wall and the outer wall of said displacer when the displacer is gyrated, and a drive shaft for driving said d
Hata Hiroaki
Hayase Isao
Inaba Koichi
Kohsokabe Hirokatsu
Takebayashi Masahiro
Antonelli Terry Stout & Kraus LLP
Hitachi , Ltd.
Vrablik John J.
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