U.S. patent application number 10/519618 was filed with the patent office on 2005-07-28 for resonant arrangement for a linear compressor.
This patent application is currently assigned to Empresa Brasileira De Compressores S.A. Embraco. Invention is credited to Berwanger, Egidio, Puff, Rinaldo.
Application Number | 20050163635 10/519618 |
Document ID | / |
Family ID | 36746222 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050163635 |
Kind Code |
A1 |
Berwanger, Egidio ; et
al. |
July 28, 2005 |
Resonant arrangement for a linear compressor
Abstract
A resonant arrangement for a linear compressor, comprising a
non-resonant assembly formed by a motor and a cylinder (1); a
resonant assembly formed by a piston (2) reciprocating inside the
cylinder (1); an actuating means (3) operatively coupling the
piston (2) to the motor, and at least one spring means presenting
an elongated tubular body (50) which is coaxial to the axis of the
piston (2) and is operatively coupled to the actuating means (3)
and to the non-resonant assembly, said tubular body (50) having at
least part of the extension therof folded in circumferential
sectors (53), each circumferential sector (53) being elastically
deformed in the axial direction upon displacement of the piston
(2).
Inventors: |
Berwanger, Egidio;
(Joinville-SC, BR) ; Puff, Rinaldo; (Joinville-SC,
BR) |
Correspondence
Address: |
DARBY & DARBY P.C.
P. O. BOX 5257
NEW YORK
NY
10150-5257
US
|
Assignee: |
Empresa Brasileira De Compressores
S.A. Embraco
Joinville-SC
BR
|
Family ID: |
36746222 |
Appl. No.: |
10/519618 |
Filed: |
February 11, 2005 |
PCT Filed: |
July 8, 2003 |
PCT NO: |
PCT/BR03/00090 |
Current U.S.
Class: |
417/415 ;
417/416; 417/417; 417/418; 417/545 |
Current CPC
Class: |
F04B 35/045
20130101 |
Class at
Publication: |
417/415 ;
417/417; 417/418; 417/416; 417/545 |
International
Class: |
F04B 017/00; F04B
035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2002 |
BR |
PI 0202830-1 |
Claims
1. A resonant arrangement for a linear compressor, comprising a
non-resonant assembly formed by a motor and a cylinder (1); a
resonant assembly formed by a piston (2) reciprocating inside the
cylinder (1); an actuating means (3) operatively coupling the
piston (2) to the motor, and at least one spring means, mounted to
the resonant assembly and which is elastically and axially deformed
toward the displacement of the piston (2), characterized in that
the spring means presents an elongated tubular body (50), which is
coaxial in relation to the axis of the piston (2) and has and end
(51) operatively coupled to the actuating means (3) and an opposite
end (52) operatively coupled to the non-resonant assembly, said
tubular body (50) having at least part of the extension thereof
folded in circumferential sectors (53) that are symmetric in
relation to the axis of said tubular body (50), each
circumferential sector (53) being elastically deformed in the axial
direction upon displacement of the piston (2).
2. The resonant arrangement according to claim 1, characterized in
that the circumferential sectors (53) present the same cross
section profile.
3. The resonant arrangement according to claim 2, characterized in
that each circumferential sector (53) presents a substantially "V"
shaped profile, each circumferential sector (53) being elastically
deformed by variation of its respective dihedral angle.
4. The resonant arrangement according to claim 3, characterized in
that the circumferential sectors (53) present the same dihedral
angle.
5. The resonant arrangement according to claim 1, characterized in
that the circumferential sectors (53) are orthogonal to the
longitudinal axis of the tubular body (50).
6. The resonant arrangement according to claim 1, characterized in
that the tubular body (50) presents a non-hollow lateral surface
(54).
7. The resonant arrangement according to claim 1, characterized in
that the fixation of each end (51, 52) to the adjacent part defined
by the cylinder (1) and the actuating means (3) is obtained by one
of the processes of welding, gluing and screwing.
8. The resonant arrangement according to claim 7, characterized in
that each one of the ends (51, 52) of the tubular body (50) is
defined by a respective tubular extension not presenting the
circumferential sectors (53) and dimensioned to provide a fitting
to the respective part to which it is affixed.
9. The resonant arrangement according to claim 8, characterized in
that each part to which is affixed an adjacent end (51, 52) of the
tubular body (50) is provided with at least one circumferential
tooth (1a, 3a, 3b, 10a) which is coaxial to the axis of the piston
(1) for fitting said respective end (51, 52).
10. The resonant arrangement according to claim 9, characterized in
that each circumferential tooth (1a, 3a, 3b, 10a) is
continuous.
11. The resonant arrangement according to claim 6, in which the
cylinder (1) is closed by a cylinder head (30) defining between a
top portion of the piston (2) and said cylinder head (30) a
compression chamber (9), characterized in that the tubular body
(50) has an end (51) hermetically affixed to the cylinder (1) and
the opposite end (52) hermetically affixed to the actuating means
(3), in order to block the fluid communication between the
compression chamber (9) and the exterior of the cylinder (1)
through gaps existing between the piston (2) and the cylinder
(1).
12. The resonant arrangement according to claim 1, in which the
hermetic compressor comprises a hermetic shell (10), inside which
are mounted the resonant and the non-resonant assemblies,
characterized in that it comprises another spring means in the form
of a tubular body (50) having an end (51) affixed to the actuating
means (3) and the other end (52) affixed to the shell (10).
Description
FIELD OF THE INVENTION
[0001] The present invention refers, in general, to a constructive
arrangement for a resonant compressor of the type driven by a
linear motor to be applied in refrigeration systems and which
presents a piston reciprocating inside a cylinder.
BACKGROUND OF THE INVENTION
[0002] In a reciprocating compressor driven by a linear motor, the
gas suction and gas compression operations are performed by the
reciprocating axial movements of the piston inside a cylinder,
which is closed by a cylinder head and mounted within a hermetic
shell, in the cylinder head being positioned the suction and
discharge valves that control the admission and discharge of the
gas in relation to the cylinder. The piston is driven by an
actuating means that supports magnetic components driven by a
linear motor affixed to the shell of the compressor.
[0003] In some constructions, the piston is mounted against a
resonant spring means in the form of an assembly of flat springs,
affixed to the hermetic shell of the compressor to operate as
guides to the axial displacement of the piston and make the whole
assembly act resonantly in a predetermined frequency, allowing the
linear motor to be adequately dimensioned to continuously supply
energy to the compressor upon operation.
[0004] The piston is mounted against the spring assembly through a
flexible rod, said spring assembly is rigidly mounted against the
cylinder, and the piston, the actuator, the magnetic component, the
flexible rod, and the assembly of flat springs form together the
resonant assembly of the compressor.
[0005] In this construction, the piston is mounted against an
assembly of flat springs made of a spring steel plate, through a
flexible rod that has the function to neutralize the forces
resulting from errors occurred during production and assembly of
the parts, in order not to transmit said forces in their totality
to the piston, avoiding the wear of said piston in relation to the
cylinder.
[0006] This construction presents some disadvantages, such as the
need to have a flexible rod to neutralize the forces resulting from
the errors occurred during production and assembly of the parts.
This flexible rod is also a relatively difficult component to be
obtained, since it must be produced with special materials.
Furthermore, such flat springs are very expensive, as they require
very sophisticated cutting and finishing processes.
[0007] In another known construction, the assembly of flat springs
is replaced by a system of helical springs, in which a first
helical spring is mounted between the actuating means and the
cylinder, and a second helical spring is mounted between the
actuating means and the shell of the compressor and, in this
construction, the resonant assembly of the compressor is formed by
the piston, the actuating means, the magnet, and the helical
springs.
[0008] This construction also presents disadvantages, such as
requiring a compressor with larger dimensions, as a function of the
need to use a pair of helical springs, which cannot be properly
affixed to be submitted to traction forces.
[0009] Moreover, the helical springs have the characteristic of
generating eccentric and shearing forces on the surfaces on which
they are seated, provoking forces on the bearings of the piston of
the compressor, generating noise and wear and reducing the life of
the compressor.
OBJECTS OF THE INVENTION
[0010] Thus, it is an object of the present invention to provide a
resonant system for a linear compressor, presenting an easy and
reliable assembly and fixation, which allows said resonant system
to be submitted to traction and compressive forces during operation
of the compressor, without losing the positioning in relation to
the parts to which it is affixed, and which does not present radial
and lateral force components during the movement of the piston that
may result in radial forces to the piston.
[0011] A further object of the present invention is to provide a
resonant system of low cost and which dispenses the use of the
flexible rod and of the flat or helical springs.
SUMMARY OF THE INVENTION
[0012] These and other objectives are achieved through a resonant
arrangement for a linear compressor, comprising a non-resonant
assembly formed by a motor and a cylinder; a resonant assembly
formed by a piston reciprocating inside the cylinder; an actuating
means operatively coupling the piston to the motor, and at least
one spring means presenting an elongated tubular body, coaxial to
the axis of the piston, and which is operatively coupled to the
actuating means and to the non-resonant assembly, said tubular body
having at least part of the extension thereof folded in
circumferential sectors, each circumferential sector being
elastically deformed in the axial direction upon the displacement
of the piston.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The invention will be described below, with reference to the
enclosed drawings, in which:
[0014] FIG. 1 is a schematic longitudinal diametrical sectional
view of a hermetic compressor of the type driven by a linear motor
and presenting a resonant means, constructed according to the prior
art;
[0015] FIG. 2 is a schematic longitudinal diametrical sectional
view of a hermetic compressor of the type driven by a linear motor
and presenting another construction for the resonant means of the
prior art;
[0016] FIG. 3 is a schematic longitudinal diametrical sectional
view of a hermetic compressor of the type driven by a linear motor
and presenting a resonant means constructed according to the
present invention;
[0017] FIG. 4 illustrate, schematically, the compressor shown in
FIG. 3, in a constructive variation of the present invention;
[0018] FIG. 5 is a schematic lateral view of the resonant means of
the present invention; and
[0019] FIG. 6 is a schematic perspective view of the resonant means
of the present invention illustrated in FIG. 5.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0020] The present invention will be described in relation to a
reciprocating compressor driven by a linear motor of the type used
in refrigeration systems and comprising a motor-compressor
assembly, including a non-resonant assembly formed by a linear
motor and a cylinder 1, and a resonant assembly formed by a piston
2 reciprocating inside the cylinder 1, and an actuating means 3,
external to the cylinder 1 and carrying a magnet 4 that is axially
impelled upon energization of the linear motor, said actuating
means 3 operatively coupling the piston 2 to the linear motor.
[0021] According to the prior art construction illustrated in FIGS.
1 and 2, the components mentioned above are mounted inside a
hermetic shell 10.
[0022] As illustrated in the enclosed figures, the linear motor is
mounted around the cylinder 1 and the piston 2 and comprises a
stack of internal laminations 5 with a coil 6 inserted therein, and
a stack of external laminations 7.
[0023] In the construction illustrated in FIGS. 1 and 2, the
compressor also includes conventional resonant spring means,
mounted in constant compression to the resonant assembly and to the
non-resonant assembly, and which are elastically axially deformable
in the displacement direction of the piston 2.
[0024] In the construction of FIG. 1, the compressor comprises a
spring means, in the form of an assembly of flat springs 10 made of
a spring steel plate and to which is mounted the piston 2 through a
flexible rod 8.
[0025] In the embodiment of FIG. 2, the compressor comprises a pair
of spring means, for example a pair of helical springs 20, a first
helical spring 20 mounted between the actuating means 3 and the
cylinder 1, and a second helical spring 20 mounted between said
actuating means 3 and the shell 10 of the compressor.
[0026] According to the illustrations, the cylinder 1 has an end
closed by a valve plate 30, provided with a suction valve 31 and a
discharge valve 32, which allows the selective fluid communication
between a compression chamber 9 defined between a top portion of
the piston 2 and the valve plate 30 and respective internal
portions of a cylinder head 40 that are respectively maintained in
fluid communication with the low and high pressure sides of the
refrigeration system to which the compressor is coupled.
[0027] These constructions present the disadvantages discussed
above.
[0028] According to the present invention, the prior art
disadvantages are avoided with a resonant arrangement for a linear
compressor that comprises at least one spring means presenting an
elongated tubular body 50, which is coaxial to the axis of the
piston 2 and has an end 51 operatively coupled to the actuating
means 3, and an opposite end 52 operatively coupled to the
non-resonant assembly, said tubular body 50 having at least part of
its extension folded in circumferential sectors 53 that are
symmetric in relation to the axis of said tubular body 50, and for
example, orthogonal to the axis of the piston 2, each
circumferential sector 53 being elastically deformed in the axial
direction upon the displacement of piston 2.
[0029] According to a way of carrying out the present invention,
the circumferential sectors 53 present the same cross section
profile, for example a substantially "V" shaped profile, such as
illustrated in FIG. 5, or a substantially "U" shaped profile.
[0030] In the construction illustrated in which the circumferential
sector 53 has a "V" shaped profile, the elastic deformation of each
said circumferential sector 53 upon displacement of the piston
occurs by variation of its respective dihedral angle.
[0031] Although in the illustrated constructive alternative the
circumferential sectors 53 present the same dihedral angle, it
should be understood that the solutions in which the
circumferential sectors 53 present different cross section profiles
along the longitudinal extension of the tubular body 50 and
different dihedral angles to said circumferential sectors 53 are
also possible.
[0032] According to a way of carrying out the present invention,
the tubular body is hollow, allowing for the fluid communication
between the compression chamber 9 and the interior of the shell 10,
which in this case is of the conventional hermetic type.
[0033] In the embodiment of the invention, as illustrated, the
tubular body 50 presents a non-hollow lateral surface 54. In this
case, since an end 51 of the tubular body 50 is hermetically
affixed to the cylinder 1, and the opposite end 52 is hermetically
affixed to the actuating means 3, said tubular body 50 blocks the
fluid communication between the compression chamber 9 and the
exterior of cylinder 1 through gaps existing between the piston 2
and the cylinder 1. In this construction, the shell of the
compressor, if provided, does not need to be hermetic, since the
sealing between the compression chamber 9 and the interior of said
shell is obtained by the tubular body 50.
[0034] According to the illustration in FIG. 3, the compressor
further presents another spring means in the form of a tubular body
50, having an end 51 affixed to the actuating means 3, and the
other end 52 affixed to the shell 10. The fixation of each of the
ends 51, 52 of each tubular body 50 to the respective parts defined
by the cylinder 1, the actuating means 3, and the shell 10 is
achieved for example, by one of the processes of welding, gluing or
screwing.
[0035] In a form of executing the invention, each of the ends 51,
52 of each tubular body 50 is defined by a respective tubular
extension not presenting the circumferential sectors 53 and which
is dimensioned to provide a fitting to the respective part to which
it is affixed. However, other constructive forms for said ends 51,
52 are possible, such as radial projections to be orthogonally
affixed to the axis of the piston 2.
[0036] In the illustrated construction, each part to which is
affixed an adjacent end 51, 52 of the tubular body 50 is provided
with at least one circumferential tooth that is coaxial to the axis
of the piston 2 in order to fit said respective end 51, 52.
[0037] According to the illustrations in FIG. 3, a lower end
portion of the cylinder 1 is provided with an annular cutting 1a,
which defines the tooth for the fixation of an adjacent end 51 of
the tubular body 50, and the actuating means 3 is provided with a
first annular tooth 3a facing the cylinder 1 and securing the other
end 52 of the tubular body 50.
[0038] In the construction presenting two spring means, such as
illustrated in FIG. 4, the actuating means 3 is further provided
with a second annular tooth 3b, facing a lower portion of the shell
10 in order to affix an end 51 of other tubular body 50. In this
construction, the shell 10 presents a respective annular salience,
which is coaxial and aligned in relation to the second tooth 3b of
the actuating means 3 that secures the other end 52 of the tubular
body 50. In the illustrated constructions, the circumferential
teeth are continuous, coaxial and axially aligned to each
other.
* * * * *