Abstract: The present invention discloses a linear compressor including a shell, a compressor main body installed in the shell and composed of a cylinder, a piston reciprocated inside the cylinder to compress refrigerant, and a linear motor for driving the piston, and elastic members spaced apart from the bottom of the shell to support the compressor main body inside the shell. In this configuration, since installation positions of the elastic members approach a gravity center of the compressor main body, a rotation moment imparted to the elastic members can be lowered and vibration of the compressor main body can be reduced.

Abstract: A compressor may include a shell, a compression mechanism, a motor, a base member, and a mounting foot. The compression mechanism may be disposed within the shell and the motor may be drivingly engaged with the compression mechanism. The base member may be coupled to the shell and a mounting foot may be fixed to the base member. The mounting foot may include a mounting aperture extending therethrough and a slot intersecting said aperture that attenuates vibrations within an operating frequency range of the compressor.

Abstract: A fixing mechanism fixes a side of a fan frame having a plurality of cooling fans and provided with a locking elastic tab having a second locking portion to a bottom board of a housing of an electronic device. The fixing mechanism includes a fixing tab fixed to the bottom board; a locking tab corresponding to the locking elastic tab and vertically installed on the fixing tab for fixing the fan frame, the locking tab having a first locking portion for being locked to the second locking portion; and an elastic buffer installed between the first locking portion and the second locking portion, for reducing vibration generated due to the spinning of the cooling fans.

Abstract: An axially driven piston-cylinder unit comprising a cylinder, a piston that can be moved back and forth in the axial direction of the cylinder, between first and second piston positions, and a drive element that can be moved back and forth in the axial direction of the cylinder and is mechanically connected to the piston by means of a piston rod. The piston rod is connected to the piston or the drive element against the pretension of an elastic device, in such a way that it can be moved axially in relation to the piston or the drive element, such that when the piston head comes into contact with the front wall of the cylinder borehole, on the side of the cylinder head, the other movement of the drive element is performed against the force of the elastic device, thus braking the drive element.

Abstract: Disclosed is a compressor for hermetically sealed small refrigeration machines. Said compressor comprises a cylinder with a cylinder housing (4) and a piston that is guided in the piston bore of the cylinder and is used for compressing a working medium, the cylinder being closed in an axial direction by means of a cylinder head (1). According to the invention, a fastening element (2, 24, 25) is provided which fixes the cylinder head (1) to the cylinder housing (4) using contact pressure that is applied in the area of the axis of the piston bore. Said fastening element can be embodied as a clamp (2), a locking clip (24), or an elastically bendable fastening means (25) such as a rope (25). The clamp (2) can be provided with a base part (5) and lateral parts (6), for example, the base part (5) being disposed in front of the cylinder head (1) in an axial direction.

Abstract: A pre-compressed vibration damper is provided for inhibiting transfer of vibration to an apparatus during the evacuation thereof by a pump.

Abstract: A compact air pump and valve package includes pump and valve assemblies integral with a pressure housing defining inlet ports and a plurality of fittings for connecting air lines to an interior of the pressure housing. The linear diaphragm pump assembly has a permanent magnetic shuttle mounting two diaphragms reciprocated by an electromagnet. The valve assembly has a plurality of solenoid valves disposed within the pressure housing, each solenoid valve being operable to control flow into or out of the pressure housing through an associated one of the plurality of fittings. Thus, no tubes or hoses are required to transfer air from the pump assembly to the valves. The housing has special mounts to isolate vibration arising from movement of the shuttle.

Abstract: A mounting arrangement for a refrigerator fan, comprising an electric motor (11) to whose shaft is affixed a propeller (12) with an axial flow passing through a refrigerated air outlet (4b) provided through an internal divisional wall (6) of the refrigerator; a support frame (20) having a marginal portion (21) and incorporating a central hub (22) in which is affixed the electric motor (11); a flexible support (30) in the form of an annular flange presenting an outer portion (31), which is peripherally and removably affixed to the contour of the refrigerated air outlet (4b), an inner portion (32) provided with a central opening (35) and with retaining means (36), which are removably locked to the marginal portion (21) of the support frame (20); and an annular membrane portion (33) interconnecting the outer portion (31) and the inner portion (32), in order to allow for small relative axial and radial displacements therebetween.

Abstract: A vehicle fan motor for an electric fan assembly includes a motor housing, a motor assembly enclosed in the motor housing, and a universal mounting arrangement radially and outwardly extended from the motor housing for securely mounting the motor housing to the electric fan assembly. The universal mounting arrangement contains first through sixth alignment holes radially and spacedly provided on a circumferential side of the motor housing. Therefore, the motor housing is adapted for securely mounting to the electric fan assembly having three mounting holes when the first, third and fifth alignment holes of the universal mounting arrangement are coaxially aligned with the three mounting holes respectively, and the motor housing is adapted for securely mounting to the electric fan assembly having four mounting holes when the first, second, fourth and sixth alignment holes of the universal mounting arrangement are coaxially aligned with the four mounting holes respectively.

Abstract: A gas turbo pump assembly for connection to a port of a vacuum chamber and having high throughput with low vibration. The assembly comprises a turbo pump and a vibration damper. The pump has a pump body with an external surface and a center axis defining a first axial end and a second axial end of the pump. The pump also has a pump inlet port, the inlet port being coupled to the vacuum chamber port disposed at the first axial end of the pump, and an exit port disposed proximate the second axial end of the pump. The assembly vibration damper is structured to enclose a substantial portion of the pump in a nested arrangement.

Abstract: In a reliability-improving structure of a reciprocating compressor, by minimizing vibration noise occurred in operation, adjusting a quantity of compression gas accurately, measuring an air gap in order to uniform an air gap of a reciprocating motor in an assembly process and firming combination between an inner stator combined with a piston for compressing gas so as to perform a linear reciprocating motion with the piston and a magnet fixedly combined with the inner stator, reliability of a reciprocating compressor can be improved.

Abstract: A single piece offset mounting foot is positioned between the compressor and the floor of a cabinet for the compressor. The offset mounting foot has a main body having a geometric shape with a top and bottom surface connected by sidewalls that form a perimeter. A depression in the top surface receives a compressor and is offset in the direction of one of the sidewalls. A plurality of substantially equally spaced legs extend outward from the main body. The thickness of the offset mounting foot may be substantially uniform through the main body. The profile of the top surface in the main body is substantially concave forming a bowl-like surface that transitions smoothly from a minimum within the concave surface or concavity to a maximum in the direction toward the periphery and in the direction away from the center of the concavity. The bottom surface of the main body is configured or profiled to contact the floor or base of the cabinet into which the compressor is to be installed.

Abstract: A compressor assembly including a housing, a motor operatively linked to a compressor mechanism, a support structure, and a sheet of closed cell foam material. The motor and compressor mechanism are disposed within the housing. The housing, motor, and compressor mechanism define a compressor assembly weight. The foam material includes a first and an opposite second surface. The first and second surfaces are adhered to the housing and support structure, respectively, and substantially all of the compressor assembly weight is supported by the foam material. A method of mounting a compressor assembly including coupling a motor and a compressor mechanism, mounting the motor and compressor mechanism within a housing, and mounting the housing to a support structure wherein a sheet of closed cell foam material is disposed between the housing and the support structure and substantially all of the compressor assembly weight is supported by the foam material.

Abstract: A refrigerator comprises: a body having a storage chamber and a mechanical chamber; a base plate arranged in the mechanical chamber without a direct contact with the body, and having a compressor; a first supporting member coupled to the body and supporting the body; and a second supporting member installed at a bottom of the base plate and supporting the base plate. A load of the body and a load of components inside the mechanical chamber are individually supported, so that vibration generated from the compressor, etc. is prevented from being transmitted to the body.

Abstract: A hermetic electric compressor including sealed container and coil spring provided for elastically supporting electric compression element housed in sealed container. A consideration has been made to avoid the coincidence in the resonance frequency between coil spring mounted with electric compression element and mechanical vibration caused by electric compression element, or a cavity formed in space. By so doing, creation of a resonation with coil spring is suppressed, and noises and vibrations with the hermetic electric compressors are reduced.

Abstract: In the invention, the atmosphere in a process chamber is conditioned using a primary pump, a secondary pump, speed control means for controlling the speed of the primary pump, and at least first gas analyzer means adapted for analyzing the extracted gases upstream from the primary pump and for producing first analysis signals. First signal processing means control the pumping speed as a function of the first analysis signals, so as to determine the variation in the pressure inside the process chamber during the transient stages of the treatment. In this way, deposits and turbulence are avoided in the process chamber, as are deposits in the pumping line, so that the secondary pump can be placed in the immediate vicinity of the process chamber.

Abstract: A reciprocating compressor with a linear motor having an actuating means operatively coupling a reciprocating piston to the motor; and a resonant spring means mounted under constant compression to the actuating means by the mutual seating of a pair of supporting surface portions, at least one of the latter being operatively associated with one of the spring means and the actuating means, against a respective pair of convex surface portions, each of the latter being operatively associated with the other of said parts, the convex surface portions being symmetrical and opposite in relation to the axis of cylinder, the supporting surface portions and the convex surface portions being mutually seated and operatively associated with the respective parts of the spring means and the actuating means, in order to transmit, by the mutually seated surface portions, the opposite axial forces with such intensity as to minimize the moments on the piston.

Abstract: A cooling mechanism for cooling an electric driving part of an injection molding machine, includes a cooling part for cooling the electric driving part; and an actuating part actuated by being supplied an actuating fluid, the actuating fluid being in fluid communication with the cooling part. The actuating fluid may be used as a cooling fluid for cooling the electric driving part.

Abstract: An arrangement of an oil-free compressor apparatus on a rail vehicle for supplying compressed air to pneumatic units assigned to the rail vehicle. The arrangement includes an oil-free compressor and a cooler unit connected with the compressor. The arrangement also includes a rail vehicle having a floor with at least one opening. The compressor is fastened on at least one side to the vehicle floor such that a main axis of rotation of the compressor is arranged essentially vertical with respect to the vehicle floor. The cooler unit interacts with the at least one opening that is configured to take in cooling air to cool the compressor.

Abstract: A vibration isolating fuel pump assembly comprises a stationary support (14) to be mounted in a fuel tank. An inner retainer (16) is fitted in the stationary support (14). The inner retainer (16) has a retainer body (18) and at least two flexible legs (20) extending substantially vertically and connected to the periphery of the retainer body (18), the upper ends of the flexible legs (20) being firmly supported by the stationary support (14) in the upper part thereof. A fuel pump (12) is received in the retainer body. Each flexible leg has its lower end connected to the retainer body via a resilient connecting element having a generally S-shape profile.

Abstract: A reciprocating compressor includes a case to which a suction pipe and a discharge pipe are respectively connected, having a closed space; a reciprocating motor disposed inside the case, for generating a reciprocating force; a compressing unit receiving the reciprocating force generated from the reciprocating motor, for compressing a fluid; and a separation plate for dividing the closed space of the case into a low pressure portion into which a fluid is sucked through the suction pipe and a high pressure portion from which a fluid compressed in the compressing unit is discharged. Accordingly, the reciprocating compressor cuts off vibration generated from the compressing unit and the reciprocating motor and thus reduce the vibration transmitted to the compressor case and other elements so that noise can be reduced, life spans of other elements can be lengthened, and reliability of the compressor can be improved.

Abstract: An electric fuel pump includes a pump proper (1) having a pump body (2) that includes an induction orifice (3), a delivery orifice (4), and electrical terminals (5,6). A cage (7) is arranged around said pump body. A filtering element (15) is connected to the cage and communicates with the induction orifice. A tubular vibration damping element (16) is arranged about the cage. A pump casing (17) is assembled about the vibration damping element so that the vibration damping element is disposed between the pump casing and the cage to prevent contact.

Abstract: A device comprising a rotor and fan rotatably mounted on a shaft which is rigidly fixed relative to a vehicle surface. The device is fixable on a vehicle surface by means of two clamping portions which are moveable towards each other along the shaft to press against a surface between them.

Abstract: A fuel tank comprises a shell made by assembling together at least two tank portions each made by molding a thermoplastic material and, when assembled together, defining the inside surface of the tank. The tank has a fuel pump fixed to its inside surface before the tank portions are assembled together.

Abstract: A method and apparatus for reducing the vibration and noise from a pump that is located in an analyzer. Vibration and noise dampening materials are used to secure the pump so that the vibration and noise are kept to a minimum, thereby, making it more comfortable for an operator to hold the device.

Abstract: The present invention relates to an elastic member and apparatus for a refrigerator compressor. A vibration absorption apparatus for a refrigerator compressor according to the present invention is connected to a foot of the compressor for transmitting the vibration generated when the compressor is operated, and includes an elastic member having a hollow passing through the central portion in an axial direction is formed; a base pan installed on a bottom of the refrigerator machinery room, for supporting the elastic member; a stand coupled with the base pan and passing through the hollow of the elastic member; and a stopper installed on the stand, for preventing the elastic member from being escaped from the base pan. The elastic member comprises a body having a plurality grooves enclosing an inner surface and outer surface thereof to have a vertical section in a zigzag; a projection of an upper portion of the body to which the stopper is forcedly attached; and a base being a lower portion of the body.

Abstract: Disclosed is a vibration absorbing apparatus for a compressor of a refrigerator. The vibration absorbing apparatus includes: an elastic member for absorbing a vibration generated during an operation of a compressor; a base pan supporting the elastic member; a stand installed in the base pan to prevent the elastic member from being bent; and a stopper installed in an upper portion of the stand to prevent the elastic member from being escaped from the base pan during a vibration of the compressor. The elastic member includes: a body having a plurality of grooves enclosing an interior surface and an exterior surface thereof, and a hollow axially passing through a central portion of the body; and a base being a lower portion of the body and being mounted on the base pan.

Abstract: Provided is a connecting structure for a vacuum pump, which can block propagation of electrical noise, generated by a main body of the vacuum pump. Between both ends of a connection piping for connecting the vacuum pump to a vacuum chamber of an apparatus to be connected with and evacuated by the vacuum pump, there is interposedly provided an electrical insulating portion formed of an insulating material so as to provide electrical insulation therebetween. The electrical insulation portion may be provided to a connection piping member such as a damper (or a valve depending on the connection arrangement) for absorbing mechanical vibrations.

Abstract: A linear compressor vertically mounted inside a hermetic shell (8) and including: a reference assembly with elements including a block defining a cylinder (2); a resonant assembly with elements including an actuator (4) that carries a piston (1) within the cylinder (2). There are provided: a first resilient element (20) mounted between the resonant assembly (1,4,5) and one end of the shell (8); a second resilient element (21) mounted between the reference assembly (2) and the other end of the shell (8); and a third resilient element (22) mounted between the reference assembly (2) and the resonant assembly (4), with the first and the second resilient elements (20,21) applying opposite forces to the shell (8) upon reciprocation of the piston (1).

Abstract: A reciprocating compressor includes: a reciprocating motor, an outer stator and an inner stator provided with at least one step portion at both sides thereof, and an armature linearly moving therebetween; a compression unit having a cylinder and a piston inserted in the cylinder to receive a linear and reciprocal driving force of the reciprocating motor and compress a gas; a suction unit sucking a gas into the compression unit; a discharge unit discharging the gas compressed in the compression unit to outside the container; a resonance spring unit elastically supporting the piston and the armature; and a frame unit supporting the compression unit and the reciprocating motor. Because stable driving is achieved in its operation, generation of vibration and noise can be minimized, heightening reliability. In addition, the amount of gas discharge can be accurately controlled.

Abstract: A linear motor includes an outer yoke formed of a core made of thin magnetic plates laminated and a coil, an inner yoke formed of a core made of thin magnetic plates laminated and permanent magnets rigidly stuck on this laminated core, and an output shaft fixed to the inner yoke.

Abstract: A dishwasher pump mounting assembly is provided, and includes a pump mounting plate which is supported by the bottom wall of the dishwasher tub and extends through a hole in the bottom wall. A plurality of locking members secure the pump mounting plate to the bottom wall and prevent upward movement of the housing. Each lock member includes a pivotal lever moveable between locked and unlocked position, and a slideable plunger movable between extended and retracted positions within the lever. In the extended position, the plunger maintains the lever in the locked position. In the retracted position, the lever is free to be pivoted between the unlocked and locked positions.

Abstract: In a fuel feed unit, a pump holder has a plurality of sheet-metal strips for limiting the transmission of structured-borne sound from a fuel pump to an anti-surge pot. The sheet-metal strips can be manufactured cost-effectively and adapted to the particular fuel pump. This enables the fuel feed unit to be manufactured particularly cost-effectively.

Abstract: Disclosed is a mounting structure of a blower for a vacuum cleaner comprising a mounting cover for fixing the blower to a body base so that the blower is structurally separated from a body cover. The mounting cover is put on the upper surface of the blower disposed on supporting ribs, and connected to the body base, and then the body cover is put on the body base. The blower is fixedly interposed between the supporting ribs and the mounting cover and separated from the body cover, thereby preventing oscillation generated by the blower from being transmitting to the body cover and then preventing the oscillation of the body cover and the consequently occurring noise of the body cover.

Abstract: An air compressor with shock-absorption rubber strips at a bottom thereof, wherein the air compressor has an air compressor. At least one shock-absorption rubber strip is installed to the air compressor bottom plate; the shock-absorption rubber strip is firmly secured to the air compressor bottom plate. The shock-absorption rubber strip is installed with a plurality of elastic foot pad so that when the air compressor is actuated, the elastic foot pad will absorb the shock of a casing of the air compressor.

Abstract: A vibration dampening system for a reciprocating compressor with a linear motor of the type comprising a motor-compressor assembly having a reference assembly (20) formed by a motor and a cylinder (4) and mounted inside a shell (1) and a resonant assembly (10) formed by a resonant spring (3) and piston (2) reciprocating inside the cylinder (4), the system comprising at least one first balancing means (30) connecting the reference assembly (20) to the shell (1), and at least one second balancing means (40) connecting the resonant assembly (10) to the shell (1), both balancing means (30, 40) actuating according to the displacement direction of the piston (2), said second balancing means (40) presenting a coefficient of elasticity proportional to the coefficient of elasticity of the first balancing means (30) by a factor defined by the ratio of the masses of the resonant assembly (10) and of the reference assembly (20), respectively.

Abstract: A compressor assembly including a motor, a compressor operably driven by the motor to discharge a compressed fluid, a tank in fluid communication with the compressor to receive compressed fluid discharged from the compressor, and at least one fluid chamber positioned between the compressor and a support surface, the at least one fluid chamber being configured to receive a portion of the compressed fluid discharged from the compressor to generate a desired fluid pressure within the fluid chamber to support the compressor relative to the support surface.

Abstract: A vacuum pump (1) includes a housing (2) in which a suction inlet opening (5) is defined. A vibration absorber (7) includes a suspension body (8) and an absorber jacket (9). The housing (2) of the vacuum pump (1) is connected directly to one end of the suspension body (8) in vacuum-tight connection and an opposite end of the suspension body carries a connecting port (14). By connecting the suspension body directly with the housing without mechanically releasable interconnection elements, the overall height of the pump and suspension body assembly is reduced.

Abstract: A water pump includes a driven portion, a shaft including a hollow portion for rotating with the driven portion as a unit, an impeller rotating with the shaft as a unit, a body including a cylindrical supporting portion inserted by the shaft, a bearing provided between an external peripheral surface of the supporting portion and an internal peripheral surface of the driven portion for rotatably supporting the driven portion, and a mechanical seal sealing one side of a cylindrical space defined between an external peripheral surface of the shaft and an internal peripheral surface of the supporting portion, wherein a vibration absorption member is provided in the hollow portion of the shaft.

Abstract: A hermetic compressor, in which a damping unit is mounted on an inner surface of a hermetic casing to stably and elastically support the hermetic casing and change a resonant frequency of the hermetic casing. The damping unit is provided at a predetermined position of an upper casing part of the hermetic casing to elastically support the upper casing part with predetermined elasticity. The damping unit has a mounting part at which the damping unit is mounted to the upper casing part, and an elastic support part to elastically support the upper casing part. The elastic support part has a flange part projected in a direction to a length which exceeds a plane aligned with a surface of the mounting part. The flange part thus elastically supports the hermetic casing in a state of being elastically deformed. The elastic support part also has a wing part to connect the flange part to the mounting part. The wing part is rounded in a direction opposite to a projected direction of the flange part.

Abstract: A structure for reducing noise and vibration in a scroll compressor includes an outer casing connected with a suction pipe and a discharge pipe respectively. The scroll compressor also includes an inner casing combined with the inner circumferential surface of the outer casing, a driving motor combined with the inner circumferential surface of the inner casing for generating a rotational force, a driving shaft combined with a rotor for transmitting the rotational force, a fixed scroll for forming a plurality of compression pockets which continuously move and which is combined with an orbiting scroll orbiting eccentrically with the driving shaft.

Abstract: Disclosed is a vibration absorbing apparatus for a compressor of a refrigerator. The vibration absorbing apparatus includes: an elastic member for absorbing a vibration generated during an operation of a compressor; a base pan supporting the elastic member; a stand installed in the base pan to prevent the elastic member from being bent; and a stopper installed in an upper portion of the stand to prevent the elastic member from being escaped from the base pan during a vibration of the compressor. The elastic member includes: a body having a plurality of grooves enclosing an interior surface and an exterior surface thereof, and a hollow axially passing through a central portion of the body; and a base being a lower portion of the body and being mounted on the base pan.

Abstract: A base for an air compressor includes a convex H-shaped member made of resilient material and provided with four legs, the convex H-shaped member being provided with a plurality of internally threaded tubular member on a top thereof, each of the legs having an end provided with raised lines; and four rubber pads each adapted to engage with the end of each of the Legs, whereby the base will function as a shock absorber for the air compressor thereby absorbing the vibration force generated by the air compressor and therefore reducing the noise. Furthermore, the air compressor can operate more smoothly and steadily.

Abstract: A linear compressor vertically mounted inside a hermetic shell (8) and including: a reference assembly with elements including a block defining a cylinder (2); a resonant assembly with elements including an actuator (4) that carries a piston (1); and a linear electric motor including a magnet member (5) and a coil (6) for driving the actuator that reciprocates the piston (1) within the cylinder (2). There are provided: a first resilient element (20) mounted between the resonant assembly (1, 4, 5) and one end of the shell (8); a second resilient element (21) mounted between the reference assembly (2) and the other end of the shell (8); and a third resilient element (22) mounted between the reference assembly (2) and the resonant assembly (4), with the first and the second resilient elements (20, 21) applying opposite forces to the shell (8) upon reciprocation of the piston (1).

Abstract: A foot plate for mounting a compressor includes a mounting plate, a pair of upwardly extending flanges, a pair of downwardly extending flanges and an upwardly extending mounting flange. The mounting flange is utilized to secure a compressor by being attached to the shell of the compressor. When tandem compressor assemblies are used, the pair of upwardly extending flanges provide clearance for a pair of rails which interconnect the tandem compressors without having to modify the foot plates. In one embodiment, the foot plates are welded or brazed to the rails. In another embodiment, a set of grommets position the foot plate on the rail and the foot plate is bolted to the rail. In another embodiment, a set of grommets position and secure the foot plate to the rail.

Abstract: An air pump having a high efficiency anti-vibration bottom seat is disclosed. The air pump includes a bending plate and a plurality of anti-vibration pegs. The vibration generated by the air pump is eliminated by the bending plate in combination with the anti-vibration pegs. The high frequency noise of the air pump is also reduced greatly by the combination of the bending plate and the anti-vibration pegs.

Abstract: Contact noise occurring continuously in a hermetic electrically driven compressor is reduced.

Abstract: A fuel supply module mounting structure for a fuel tank (1) is disclosed having a fuel tank module (6) comprised of a tilting mechanism (TM) disposed between an upper plate (5) and a case (8,30) and operative to cause the case to be tilted in a direction away from a valve (20) in response to vertically upward movement of the case in a value beyond a given amount of stroke upon abutting engagement of the case with a bottom wall portion (3) of the fuel tank, avoiding interference between the valve (20) and a pump (9) contained in the case (8,30).

Abstract: In a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, the vane member is discrete from the casing, a vibration propagation between the vane member and the casing is prevented or restrained, and a vibration of a pipe extending from the casing is absorbed.

Abstract: A linear compressor is provided in which a driving spring and an elastic supporting member for supporting a compressing mechanism portion are disposed such that a piston and the compressing mechanism portion move in opposite phases such that vibration of a hermetic vessel is canceled out. The linear compressor comprises a hermetic vessel having a compressing mechanism portion and a linear motor therein. The compressing mechanism portion includes a piston-side mechanism and a cylinder-side mechanism, the former includes the piston and the mechanism member which is movable together with the piston, the latter includes the cylinder and the stator which connects with the cylinder. The cylinder-side mechanism member is elastically supported at opposite ends in the hermetic vessel by a first elastic member, and a reciprocating force in the axial direction is given the piston-side mechanism by a second elastic member whose one end is supported by the hermetic vessel.