Electrical generator or motor structure – Dynamoelectric – Linear
Reexamination Certificate
2000-01-22
2001-12-04
Ramirez, Nestor (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Linear
C310S020000, C310S017000
Reexamination Certificate
active
06326706
ABSTRACT:
TECHNICAL FIELD OF INVENTION
This invention relates to a linear motor and a compressor incorporating such a motor.
BACKGROUND OF INVENTION
The present invention provides improvements to the invention disclosed in my UK patent no. GB-2299715-B, its disclosure is incorporated herewith by reference.
SUMMARY OF INVENTION
A first object of this invention is to provide a linear motor and/or compressor with improved energy efficiency and more compact and cost effective structure.
According to one aspect of the invention, there is provided a linear motor comprising: a stator having a magnetic arrangement defining a first plurality of axially exposed magnetic gaps; a reciprocating (shuttle) member; and means for energising the stator and/or reciprocating member; wherein the reciprocating member has a magnetic arrangement defining a second plurality of axially exposed magnetic gaps for interacting with the magnetic gaps of said stator.
According to another aspect of the invention, there is provided a linear motor compressor comprising: a housing enclosing an inner space, a stator having a magnetic arrangement defining a first plurality of axially exposed magnetic gaps; a reciprocating member disposed as a free piston in the inner space; valve means for forming at least one fluid passage into and out of said inner space; and means for energising said stator and/or reciprocating member; wherein the reciprocating member has a magnetic arrangement defining a second plurality of axially exposed magnetic gaps for interacting with the magnetic gaps of said stator.
It is advantageous to arrange between the stator and the shuttle a series of magnetic gaps along the shuttle's operating axis so that the diameters of the stator and shuttle can be made small. It is also advantageous to arrange the stator and shuttle's magnetic gaps in an interposed relationship so that it improves not only the push-and-pull driving forces but also electromagnetic suspension effects on the shuttle, therefore improving energy efficiency and reducing working load on suspension springs. Preferably the stator windings are divided into two or more groups and a phase difference is introduced in their currents to further enhance suspension effects.
In case that a stronger driving force is required by a particular application, it can be achieved conveniently by arranging more magnetic gaps along the stator and shuttle structure, forming a longer and more powerful unit. Such a relatively thin and long configuration provides better heat dissipation which is highly beneficial to a high powered unit, especially when it uses temperature sensitive rare earth magnets.
It is preferable that the shuttle member is supported by a central guide to ensure its non-contact movements relative to the stator and to form a clearance seal allowing lubricant-free operation. The central guide can be a hollow shaft extending through said reciprocating member to circulate a coolant fluid through it. Alternatively, the central guide can be formed by a pair of coaxially aligned shafts with pistons carried by the reciprocating member.
It is also preferable to form a multi-stage compression arrangement by dividing the space inside the compressor into pre-compressing and further-compressing chambers so that a process fluid can be compressed stage by stage. Advantageously, an intermediate chamber can be formed to receive compressed fluid from said pre-compressing chamber for intercooling then to supply it to said further-compressing chamber. It is advantageous to arrange second stage compression chambers outside the linear motor structure to improve heat dissipation and energy efficiency.
A further object of this invention is to provide an improved suspension mechanism for a reciprocating member in a linear motor, therefore to make the motor operation more efficient and more reliable.
According to yet another aspect of the invention, there is provided a mechanism for suspending a reciprocating member in a linear motor, wherein said linear motor has a stator with pole means for interacting with pole means on said reciprocating member to cause the latter to reciprocate between two end positions; and wherein said suspension mechanism includes magnetic spring means arranged to interact with the pole means of said reciprocating member so as to generate a return force in response to its movement towards each said end position.
Preferably, said magnetic spring means have a nested permanent magnet structure forming internal flux concentration for acting with said reciprocating member when it enters the structure. Alternatively, said magnetic spring means is formed by an electromagnet with an axially exposed magnetic gap for acting with said reciprocating member.
A further object of this invention is to provide a linear motor with a flux switching arrangement for making the motor operation more efficient.
According to yet another aspect of the invention, there is provided a flux switching mechanism for a linear motor having a stator with pole means defining a plurality of magnetic gaps for interacting with pole means on a reciprocating member, wherein the pole means of said stator incorporate flux switching means for switching magnetic flux towards one axial direction according to the direction of an energising current supplied to the stator so as to improve magnetic linkage between the stator and the reciprocating member.
Preferably the stator pole means also have a pole face extension pattern extending in axial direction to further improve said magnetic linkage.
A further object of this invention is to provide a linear motor and/or compressor with a suspension mechanism for its vibration-free operation.
According to yet another aspect of the invention, there is provided a linear motor and/or compressor having a housing accommodating a stator and a reciprocating (shuttle) member; wherein both said stator and reciprocating member are suspended to make them movable relative to the housing so that when in operation the interaction between the stator and the reciprocating member would cause them to move in opposite directions.
Preferably the stator is suspended by disk spring means which also ensures its precise alignment with the housing. It is advantageous that the disk spring means also act as diaphragm means dividing the space between the stator and the housing into chambers so that the stator's movement would also produce compression effects.
REFERENCES:
patent: 3891874 (1975-06-01), Rotors et al.
patent: 3937600 (1976-02-01), White
patent: 4067667 (1978-01-01), White
patent: 4404503 (1983-09-01), Ward et al.
patent: 4533890 (1985-08-01), Patel
patent: 4613285 (1986-09-01), Sato et al.
patent: 4704553 (1987-11-01), Resnicow
patent: 5296767 (1994-03-01), Asselin
patent: 5779455 (1998-07-01), Steiger
patent: 0238109 (1987-09-01), None
patent: 0343350 (1989-11-01), None
patent: 1196418 (1970-06-01), None
patent: 1539201 (1979-01-01), None
patent: 2266932 (1993-11-01), None
patent: 2299715 (1996-10-01), None
ACIP International, Inc.
Jones Judson H.
Ramirez Nestor
Yu Samson G.
Z & D Limited
LandOfFree
Linear motor compressor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Linear motor compressor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Linear motor compressor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2585399