US20130034456A1 - Refrigerant compressor having linear drive - Google Patents
Refrigerant compressor having linear drive Download PDFInfo
- Publication number
- US20130034456A1 US20130034456A1 US13/515,583 US201013515583A US2013034456A1 US 20130034456 A1 US20130034456 A1 US 20130034456A1 US 201013515583 A US201013515583 A US 201013515583A US 2013034456 A1 US2013034456 A1 US 2013034456A1
- Authority
- US
- United States
- Prior art keywords
- piston
- permanent magnet
- refrigerant compressor
- front side
- valve plate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B17/00—Pumps characterised by combination with, or adaptation to, specific driving engines or motors
- F04B17/03—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors
- F04B17/04—Pumps characterised by combination with, or adaptation to, specific driving engines or motors driven by electric motors using solenoids
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B35/00—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for
- F04B35/04—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric
- F04B35/045—Piston pumps specially adapted for elastic fluids and characterised by the driving means to their working members, or by combination with, or adaptation to, specific driving engines or motors, not otherwise provided for the means being electric using solenoids
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/12—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by varying the length of stroke of the working members
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B2201/00—Pump parameters
- F04B2201/02—Piston parameters
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B2201/00—Pump parameters
- F04B2201/02—Piston parameters
- F04B2201/0206—Length of piston stroke
Definitions
- the invention relates to a refrigerant compressor having a hermetically sealed compressor housing, in whose interior a piston-cylinder unit which compresses a refrigerant is arranged, whose cylinder housing is frontally closed by means of a cylinder head, in which a suction opening and a pressure opening are provided, via which refrigerant is suctioned in via a suction valve through the suction opening and compressed via a pressure valve through the pressure opening, the piston-cylinder unit having at least one piston guided in a piston bore of the cylinder housing, a workspace for compressing a refrigerant being formed between the cylinder head and a first front side of the piston, a linear drive being provided, comprising at least one oscillating body enclosed by an exciter coil, which is connected to the piston in order to move it in an oscillating manner along a piston longitudinal axis, according to the preamble of claim 1 .
- the refrigerating machine process using azeotropic gases has been known per se for some time.
- the refrigerant is heated and finally superheated by absorbing energy from the space to be cooled in a vaporizer, which results in vaporization, and is compressed to a higher pressure level by means of a piston-cylinder unit of the refrigerant compressor, where it releases heat via a condenser and is conveyed back into the vaporizer again via a throttle, in which pressure reduction and cooling of the refrigerant occur.
- Such refrigerant compressors are used in the domestic and industrial fields, where they are typically arranged on the back side of a refrigerator or refrigerated shelf.
- the piston-cylinder unit comprises a cylinder housing provided with a piston bore, in which an oscillating piston is guided.
- the piston bore of the cylinder housing is closed in a first axial end area by a cylinder head or by a valve plate, while the piston bore is open in a second axial end area for accommodating the piston or is penetrated by a connecting rod in the installed state of the refrigerant compressor.
- the cylinder head can be implemented in general, on the one hand, as a solid, cap-shaped component, for example, having a pressure chamber and a suction chamber, which carries a valve plate on its inner side. It can be implemented as a ring-shaped component, which holds the valve plate on the cylinder housing, however, it can also be implemented solely as a valve plate, which is clamped by means of a clamping device on the cylindrical part of the cylinder housing.
- the suction opening for suctioning the refrigerant out of the refrigerant circuit is then arranged in the valve plate, as well as the pressure opening, through which the compressed refrigerant is expelled by the piston after the compression procedure in the refrigerant circuit.
- the valve plate is screwed together with the front side of the cylinder housing in the most widespread refrigerant piston compressors.
- bores are arranged both on the cylinder housing and also in the valve plate, the bores in the cylinder housing each being provided with a thread, via which the screw connection is performed.
- a cylinder cover is provided, which has a pressure chamber, in which compressed refrigerant expelled from the cylinder is briefly buffered in order to overflow into the refrigerant circuit thereafter.
- Exemplary embodiments are also known in which a suction chamber corresponding to the pressure chamber is provided, via which the refrigerant is suctioned through the suction opening into the cylinder. Pressure chamber and suction chamber are separated from one another by appropriate structural measures in the cylinder cover in such cases.
- a refrigerant compressor of conventional construction comprises an electric motor, which drives the piston oscillating in the piston bore via a crankshaft.
- the piston is to be prevented from striking in the region of the top dead center on the cylinder head or on the valve plate arranged in the cylinder head.
- the top dead center of the piston is also to be prevented from being displaced too far downward, or the piston approaching the cylinder head or the valve plate is to be prevented from executing a reversal movement excessively early, thus resulting in a performance-reducing dead space.
- the disadvantage of such systems is mechanical wear in the spring elements and the piston components.
- the spring elements occupy valuable space and have proven to be inflexible if the refrigerating capacity of the refrigerant compressor or the piston stroke are to be changed.
- Linear compressors also exist in which the piston is exclusively held in position during its oscillation by an electronic controller of the linear drive.
- Such solutions for delimiting the piston travel which are known, e.g., from WO 01/48379 A and WO 2009/103138 A2, are only implementable with provision of complex sensor and analysis technology, however.
- sensors are provided which ascertain the duration of a piston movement, which is compared thereafter by a microprocessor to a reference duration stored on a storage medium and the current position of the piston is calculated therefrom.
- Such systems are costly and are therefore hardly used in standard compressor manufacturing.
- the present invention is therefore based on the problem of proposing a simple and reliable possibility for delimiting the piston travel in refrigerant compressors having linear drive, which makes both provision of mechanical spring elements and also provision of complex sensor and control electronics for delimiting the piston travel superfluous. Dead space occurring in the cylinder housing is to be reduced as much as possible.
- the piston-cylinder unit is equipped with at least one permanent magnet arrangement, comprising respectively at least one first permanent magnet arranged on the piston or on a component connected to the piston and at least one second permanent magnet arranged on the cylinder housing or on a component connected to the cylinder housing, the first permanent magnet and the second permanent magnet respectively having the same magnetic pole direction to one another, in order to generate a repelling action between the two permanent magnets to delimit the piston travel in the region of the top dead center and/or in the region of the bottom dead center upon approach of the first permanent magnet to the second permanent magnet.
- the piston travel of the piston can be limited simply and reliably in this manner. Striking of the piston on elements of the cylinder housing, in particular on the valve plate, is also prevented without electronic sensor and control elements.
- first and second permanent magnets can be arranged in arbitrary position and configuration.
- the component connected to the piston, on which the at least one first—movable—permanent magnet is arranged can be the oscillating body or a piston shaft connecting the piston to the oscillating body in a special embodiment variant of the invention.
- the component connected to the cylinder housing, on or in which the at least one second—fixed—permanent magnet is arranged, is the cylinder head in a preferred embodiment variant of the invention.
- a valve plate can be arranged in the cylinder head, the at least one second permanent magnet being arranged on the valve plate, preferably being at least sectionally countersunk in the valve plate.
- the second permanent magnet can be arranged both externally and also internally on or even entirely or partially in the valve plate.
- the delimitation of the piston travel in the bottom dead center can also be performed using permanent magnets, however, it can also be performed conventionally, for example, by means of spring elements.
- the component connected to the cylinder housing, on or in which the at least one second permanent magnet is arranged is a housing enclosing the oscillating body.
- This housing preferably is a support for the exciter winding (the stator) or the exciter winding itself.
- the at least one second permanent magnet is arranged inside the piston bore of the cylinder housing, in particular inside the working space or delimiting the working space.
- one of the permanent magnets could be countersunk into the cylinder housing so that it delimits the working space using its front side.
- the working space is formed by the cylinder housing and designates the space within the cylinder housing which the piston passes through during its oscillation.
- the at least one first permanent magnet can also be arranged outside the piston bore or the working space, e.g., as already proposed above, on the oscillating body or on the piston shaft.
- the at least one second permanent magnet being arranged in an end region of the cylinder housing, the end region facing the cylinder head. It is sensible if the at least one first permanent magnet is arranged on a second front side of the piston facing away from the cylinder head or on a piston shaft.
- a particularly simple embodiment provides that the at least one first permanent magnet is arranged in the region of the first front side of the piston facing toward the cylinder head.
- the at least one first permanent magnet is sectionally or entirely countersunk in the front side and/or in the piston shaft.
- the countersunk first and/or second permanent magnet is sheathed, preferably sheathed on all sides, by the material of the piston or the cylinder head or the valve plate.
- the permanent magnet is countersunk into the front side of the piston and/or the valve plate so that at least one free space, which communicates with the working space, is provided between permanent magnet and piston or permanent magnet and valve plate.
- This free space preferably extends along the entire periphery of the permanent magnet.
- the gap-shaped recess promotes free unfolding of the magnetic action of the permanent magnet or expansion of the magnetic field lines originating from the permanent magnet.
- Expansion of the magnetic field lines originating from the permanent magnet is promoted further in that the free space is implemented as a gap according to a preferred embodiment variant of the invention, whose clear opening width widens in the direction of the working space.
- the free space can be filled using a non-ferromagnetic material, such as plastic.
- a non-ferromagnetic material such as plastic.
- the first permanent magnet arranged on the piston side is arranged opposite to the second permanent magnet arranged on the cylinder housing.
- both permanent magnets can be arranged congruently in the piston longitudinal axis.
- the permanent magnets can be implemented as substantially cylindrical.
- the permanent magnets can be implemented as substantially ring-shaped, the ring shape preferably extending rotationally-symmetric to the piston longitudinal axis.
- the permanent magnets preferably have a ring-cylindrical shape in this case, so that countersunk permanent magnets can be enclosed by a free space in the form of a ring gap.
- the permanent magnets can also be arranged rotationally-symmetric to an axis which is parallel to the piston longitudinal axis.
- ring shape Arbitrary modifications to the ring shape are also possible, e.g., oval or elliptical shapes.
- Alternative embodiment variants would be, e.g., spiral-shaped or lattice-shaped permanent magnets.
- multiple permanent magnets are arranged concentrically around the piston longitudinal axis.
- front side of the at least one first permanent magnet arranged on the piston side extends substantially parallel to the front side of the at least one second permanent magnet arranged on the cylinder housing side, uniform implementation of the magnetic field is ensured.
- the first permanent magnet arranged on the piston side substantially has an equal field strength, therefore, in the case of identical material preferably a substantially equal mass, as the second permanent magnet arranged on the cylinder housing side. A symmetrical magnetic field is thus generated.
- a uniform magnetic field is also achieved if multiple permanent magnets are arranged on a circle extending concentrically to the piston longitudinal axis, the angle spacing of adjacent permanent magnets being substantially equal.
- the piston-side permanent magnets and the cylinder-housing-side permanent magnets are expediently respectively arranged on a circle, piston-side permanent magnets and cylinder-housing-side permanent magnets being diametrically opposite (i.e., being congruent viewed in the piston longitudinal axis).
- the piston can be implemented as a double piston, comprising two piston sections arranged on opposing end regions of the double piston, each forming one front side of the double piston.
- a first working space is formed between the first front side of the double piston and a first cylinder head comprising a first valve plate and a second working space is formed between the second front side of the double piston and a second cylinder head comprising a second valve plate.
- the oscillating body is arranged between the two front sides of the double piston, preferably enclosed by the double piston, an arrangement according to the invention of permanent magnets being provided for each cylinder head-piston section pair.
- the piston-cylinder unit is implemented according to one of claims 1 to 20 and in the case of predefined permanent magnets, the drive strength of the linear drive is set so that the piston changes its movement direction in a predefined top dead center and/or bottom dead center without using a mechanical spring element.
- the piston only changes its movement direction because of a permanent magnet arrangement in each case both at the top dead center and also at the bottom dead center.
- the piston only changes its movement direction because of a permanent magnet arrangement in one dead center, while a known spring element is used for the change of the movement direction in the other dead center.
- the piston forms a nonlinear mass-spring system jointly with the oscillating body and optionally the piston shaft.
- Different resonance frequencies are therefore possible in this mass-spring system if the full travel of the mass-spring system is not utilized, while in a linear mass-spring system, for example, in the case of exclusive use of spring elements, only one resonance frequency occurs, at which the piston is normally operated.
- a specific frequency of the linear drive is additionally predefined.
- the drive strength and/or frequency of the linear drive are set based on measured position data of the piston or magnetic field strengths.
- Hall sensors as in inductive encoders or current-voltage measurements of the exciter winding can be used.
- FIG. 1 shows a schematic view of a linear compressor according to the invention
- FIG. 2 shows a longitudinal section through a piston-cylinder unit according to the invention
- FIG. 3 shows a piston-cylinder unit according to the invention having a spring element
- FIG. 4 shows a piston-cylinder unit according to the invention having permanent magnets on the oscillating body of the linear drive
- FIG. 5 shows the embodiment variant according to FIG. 4 , the piston being located in its bottom dead center
- FIG. 6 shows a detail “B” from FIG. 4
- FIG. 7 shows a modification of the embodiment variant according to FIG. 4 with spring element
- FIG. 8 shows a schematic view of the magnetic fields developed in the region of the permanent magnets in the form of field lines (piston in bottom dead center)
- FIG. 9 shows a view as in FIG. 8 (piston on the path in the direction of top dead center)
- FIG. 10 shows a view as in FIG. 8 (piston reaches top dead center)
- FIG. 11 shows a force-distance diagram to illustrate the increase of the magnetic force upon approach of the first permanent magnet to the second permanent magnet
- FIG. 12 shows a piston-cylinder unit according to the invention having double piston
- FIG. 13 shows a schematic view of a linear compressor according to the invention arranged in a compressor housing.
- FIG. 1 schematically shows the construction of a linear compressor 23 according to the invention, which is arranged by means of a suspension device 28 within a hermetically sealed compressor housing 29 (shown in FIG. 13 ) of a small refrigerant compressor.
- the linear compressor 23 comprises a piston-cylinder unit 21 having at least one piston 3 guided in a piston bore 2 of a cylinder housing 1 .
- the cylinder housing 1 is frontally closed using a cylinder head 4 , more specifically using a valve plate 5 held in the cylinder head 4 .
- the piston 3 is movable in an oscillating manner by a linear drive 6 along a piston longitudinal axis 9 .
- the linear drive 6 comprises an oscillating body 7 , which is rigidly connected or articulated with the piston 3 , enclosed by an exciter winding (a stator) 8 .
- the oscillating body 7 is connected by means of a piston rod or a piston shaft 22 to the piston 3 .
- the piston-cylinder unit 21 is equipped with at least one permanent magnet arrangement (namely two here: 11 a and 12 a; 11 b and 12 b ), respectively comprising at least one first permanent magnet 11 a, 11 b arranged on the piston 3 or on a component connected to the piston 3 —in particular, this could be the oscillating body 7 or the piston shaft 22 in this case—and comprising at least one second permanent magnet 12 a, 12 b arranged on the cylinder housing 1 or on a component connected to the cylinder housing 1 .
- at least one permanent magnet arrangement namely two here: 11 a and 12 a; 11 b and 12 b
- this could be the oscillating body 7 or the piston shaft 22 in this case—and comprising at least one second permanent magnet 12 a, 12 b arranged on the cylinder housing 1 or on a component connected to the cylinder housing 1 .
- the at least one first permanent magnet 11 a, 11 b and the at least one second permanent magnet 12 a, 12 b respectively point in the same magnetic pole direction to one another, so that upon approach of the at least one first permanent magnet 11 to the at least one second permanent magnet 12 , a repelling effect arises between the two permanent magnets 11 and 12 and therefore an action which delimits the piston travel in the region of the top dead center and/or in the region of the bottom dead center of the piston 3 .
- a first permanent magnet 11 a is attached to the front side of the piston 3 and a further first permanent magnet 11 b, namely a ring-shaped permanent magnet, is attached to the opposing side.
- a second permanent magnet 12 a is attached to the cylinder head 4 or to its valve plate, and a further permanent magnet 12 b is attached to the opposing side of the cylinder housing 1 , where the piston shaft 22 passes through the cylinder housing 1 .
- the latter permanent magnet is implemented as ring-shaped.
- the permanent magnets 11 a and 12 a cooperate and determine on the basis of their field strength the force increase in the direction of the top dead center of the piston 3
- the permanent magnets 11 b and 12 b cooperate and establish on the basis of their field strength the force increase in the direction of the bottom dead center of the piston 3 .
- the points at which the piston 3 actually reverses can vary.
- FIG. 2 An embodiment similar to that in FIG. 1 is shown in FIG. 2 , except that in FIG. 2 a ring-shaped permanent magnet 11 is countersunk in the first front side 3 a of the piston 3 and a ring-shaped second permanent magnet 12 is countersunk corresponding thereto in the valve plate 5 of the piston 4 .
- the surface of the first permanent magnet 11 facing toward the working space 14 is in a plane with the first front side 3 a of the piston 3 .
- the surface of the second permanent magnet 12 facing toward the working space 14 is in a plane with the level inner surface of the valve plate 5 .
- the valve plate 5 has a suction opening 17 , which is closable on the inner side of the valve plate 5 using a suction valve 15 . Furthermore, it has a pressure opening 18 , which can be closed on the outer side of the valve plate 5 using a pressure valve 16 .
- the refrigerant flows via the suction opening 17 past the open suction valve 15 into a working space 14 formed between the valve plate 5 and a first front side 3 a of the piston 3 facing toward it.
- the compression stroke the piston 3 moves to the left
- refrigerant is conveyed back out of the interior of the cylinder housing 1 via the pressure opening 18 .
- the piston shaft 22 is not shown in FIG. 2 .
- the two permanent magnets 11 , 12 have identical dimensions and are manufactured from the same ferromagnetic material, so that they have equal magnetic field strength. They are implemented as ring cylinders, the inner and the outer surfaces therefore have the shape of a cylindrical sheath, the contact surface on the piston 3 has the shape of a circular ring, as does the surface of the permanent magnets 11 , 12 facing toward the working space 14 .
- Both permanent magnets 11 , 12 are countersunk in ring-shaped depressions of the piston 3 or the valve plate 5 , respectively, so that the surface of the permanent magnet 11 , 12 facing toward the working space 14 terminates level with the first front side 3 a of the piston or with the inner side of the valve plate 5 , respectively.
- the permanent magnets 11 , 12 each rest on the base of the ring-shaped depression, between the outer surface of the permanent magnets 11 , 12 , which is implemented as a cylindrical sheath, and the wall of the depression, however, a free space 13 is provided, so that the magnetic field lines—undisturbed by the metallic material of the piston 3 or the valve plate 5 —can exit through the outer surface in the form of a cylindrical sheath of the permanent magnets 11 , 12 .
- the free space 13 can also, as shown in the case of the piston 3 , be filled using a non-ferromagnetic material, for example, using plastic. The dead space is thus decreased, i.e., the space between the piston in the dead center and the valve plate which can be filled with refrigerant.
- the piston travel is delimited at the top dead center by the permanent magnets 11 , 12 using the embodiment according to FIG. 2 .
- a further first permanent magnet like permanent magnet 11 b in FIG. 1 , can also be arranged on the second front side 3 b of the piston 3 , with a corresponding permanent magnet 12 b on the cylinder housing.
- a spring element 27 can be provided, which establishes the bottom dead center of the piston 3 .
- the embodiment of the piston-cylinder unit is equivalent to that of FIG. 2 .
- the exciter winding 8 is also shown in FIG. 3 .
- the first permanent magnets 11 a, 11 b are not arranged on the piston 3 , but rather on the cylindrical oscillating body 7 of the linear drive 6 .
- the corresponding second permanent magnets 12 a, 12 b are arranged on the inner side of the housing 24 of the linear drive 6 , so that they align in the direction of the piston longitudinal axis 9 with the permanent magnets 11 a, 11 b.
- the permanent magnets 11 a, 11 b, 12 a, 12 b are also implemented as ring cylinders here, but are not countersunk in the oscillating body 7 or the housing 24 , respectively, but rather are fastened on the circular surfaces of the oscillating body 7 or on opposing inner walls of the housing 24 , respectively.
- the ring cylinders are arranged concentrically to the piston longitudinal axis 9 .
- the permanent magnets 11 a and 12 a When the piston 3 is located in the top dead center, see FIG. 4 , the permanent magnets 11 a and 12 a —viewed in the direction of the piston longitudinal axis 9 —have the least possible distance from one another because of the force of the linear drive 6 acting on the oscillating body 7 . However, the permanent magnets 11 b and 12 b have the greatest possible distance from one another, which essentially corresponds to the piston stroke of the piston 3 .
- the permanent magnets 11 b and 12 b viewed in the direction of the piston longitudinal axis 9 —have the least possible distance from one another because of the force of the linear drive 6 acting on the oscillating body 7 .
- the permanent magnets 11 a and 12 a have the greatest possible distance from one another, which essentially corresponds to the piston stroke of the piston 3 .
- FIG. 6 shows detail B from FIG. 4 in enlarged form.
- the permanent magnets 11 a and 12 a are visible of the one permanent magnet arrangement (a), only permanent magnet 11 b is visible of the second permanent magnet arrangement (b).
- the radial external diameter of the permanent magnets 11 a and 11 b almost corresponds to the radial diameter of the cylindrical oscillating body 7 , the diameter of the permanent magnets 11 a, 11 b, 12 a, 12 b is only approximately 1-5% smaller than that of the oscillating body 7 .
- FIG. 7 shows a modification of the embodiment variant according to FIG. 4 , in that the permanent magnet arrangement for establishing the bottom dead center from FIG. 4 is replaced by a spring element 27 .
- the permanent magnets 11 a and 12 a from FIG. 4 are maintained, the permanent magnets 11 b and 12 b are replaced by the spring element 27 .
- FIG. 8 shows a schematic view of the magnetic fields developed in the region of the permanent magnets 11 , 12 of FIGS. 2 and 3 in the form of field lines 25 or 26 , respectively, the piston 3 being located in the region of its bottom dead center.
- Magnetic field lines are closed, they each exit at the so-called “north pole” from the permanent magnets and enter therein at the so-called “south pole”.
- the south pole of a permanent magnet approaches the north pole of another permanent magnet, the permanent magnets attract and adhere to one another.
- the two permanent magnets repel, it is not possible or it is only possible using a specific force for the permanent magnets to approach close enough to one another so that their south poles touch.
- This principle is utilized in this invention. Since the repelling force between the magnetic poles of the same name is inversely proportional to the distance of the magnetic poles, the force for the approach of the piston 3 to the valve plate 5 is not linear to the distance between piston 3 and valve plate 5 . This is a substantial difference from a spring element arranged between valve plate 5 and piston 3 , in which the force is linearly dependent on the distance between valve plate 5 and piston 3 .
- valve plate 5 and also piston 3 are manufactured in this exemplary embodiment from steel, i.e., they are ferromagnetic themselves, therefore the magnetic field lines 25 , 26 can penetrate into the valve plate 5 and the piston 3 .
- the distance between piston 3 and piston bore 2 is shown exaggeratedly large here.
- FIG. 9 shows the piston-cylinder arrangement 21 during the progressing compression stroke, the piston is on the path in the direction of top dead center.
- the first permanent magnet 11 arranged on the first front side 3 a of the piston 3 approaches the fixed second permanent magnet 12 countersunk in the valve plate 5 .
- the magnetic fields of the two permanent magnets 11 , 12 influence one another significantly more than in FIG. 8 .
- the distance between the separate field lines 25 , 26 of the permanent magnets decreases, the magnetic field strength becomes greater, the field lines are “tensioned” similarly to a spring.
- the piston 3 has reached its top dead center. Striking of the first front side 3 a of the piston 3 on the valve plate 5 is prevented, since the two permanent magnets 11 and 12 each point toward one another with identical magnetic pole direction (with the “north pole”) and therefore repel one another. If the exciter field of the exciter winding 8 was now turned off, the piston 3 would be displaced to the right by the repelling force of the permanent magnets 11 , 12 .
- the piston travel in the region of the bottom dead center can also be delimited in the same fundamental way as the piston travel was delimited according to FIGS. 8-10 in the region of the top dead center.
- FIG. 11 shows a force-distance graph to illustrate the increase of the magnetic force during the approach of the first permanent magnet 11 to the second permanent magnet 12 .
- the distance between first permanent magnet 11 and second permanent magnet 12 in centimeters is plotted on the horizontal axis
- the magnetic force F in % is plotted on the vertical axis, 100% representing the repelling magnetic force in the top dead center.
- This force must be applied by the linear drive 6 and the mass inertia of the piston 3 having oscillating body 7 to hold the piston 3 for a short time in the top dead center.
- the top dead center is given at a distance of 0.05-0.5 mm between first permanent magnet 11 and second permanent magnet 12 . Both the rhomboid measuring points and also the measuring curve interpolated based on the measuring points are shown.
- FIG. 12 shows a piston-cylinder unit according to the invention having a double piston.
- the piston 3 is implemented as a double piston and comprises two piston sections 19 , 20 , arranged on opposing end regions and each forming one front side 3 a, 3 b of the double piston.
- a first working space 14 is formed between the first front side 3 a of the double piston and a first cylinder head 4 comprising a first valve plate 5
- a second working space 14 ′ is formed between the second front side 3 b of the double piston and a second cylinder head 4 ′ comprising a second valve plate 5 ′.
- the oscillating body 7 is arranged between the two front sides 3 a, 3 b of the double piston, preferably enclosed by the double piston 3 .
- One permanent magnet arrangement 11 a, 12 a or 11 b, 12 b according to the invention is provided for each cylinder head-piston section pair 4 / 19 or 4 ′/ 20 .
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
Abstract
Description
- The invention relates to a refrigerant compressor having a hermetically sealed compressor housing, in whose interior a piston-cylinder unit which compresses a refrigerant is arranged, whose cylinder housing is frontally closed by means of a cylinder head, in which a suction opening and a pressure opening are provided, via which refrigerant is suctioned in via a suction valve through the suction opening and compressed via a pressure valve through the pressure opening, the piston-cylinder unit having at least one piston guided in a piston bore of the cylinder housing, a workspace for compressing a refrigerant being formed between the cylinder head and a first front side of the piston, a linear drive being provided, comprising at least one oscillating body enclosed by an exciter coil, which is connected to the piston in order to move it in an oscillating manner along a piston longitudinal axis, according to the preamble of
claim 1. - The refrigerating machine process using azeotropic gases has been known per se for some time. The refrigerant is heated and finally superheated by absorbing energy from the space to be cooled in a vaporizer, which results in vaporization, and is compressed to a higher pressure level by means of a piston-cylinder unit of the refrigerant compressor, where it releases heat via a condenser and is conveyed back into the vaporizer again via a throttle, in which pressure reduction and cooling of the refrigerant occur. Such refrigerant compressors are used in the domestic and industrial fields, where they are typically arranged on the back side of a refrigerator or refrigerated shelf.
- The piston-cylinder unit comprises a cylinder housing provided with a piston bore, in which an oscillating piston is guided.
- The piston bore of the cylinder housing is closed in a first axial end area by a cylinder head or by a valve plate, while the piston bore is open in a second axial end area for accommodating the piston or is penetrated by a connecting rod in the installed state of the refrigerant compressor.
- The cylinder head can be implemented in general, on the one hand, as a solid, cap-shaped component, for example, having a pressure chamber and a suction chamber, which carries a valve plate on its inner side. It can be implemented as a ring-shaped component, which holds the valve plate on the cylinder housing, however, it can also be implemented solely as a valve plate, which is clamped by means of a clamping device on the cylindrical part of the cylinder housing. The suction opening for suctioning the refrigerant out of the refrigerant circuit is then arranged in the valve plate, as well as the pressure opening, through which the compressed refrigerant is expelled by the piston after the compression procedure in the refrigerant circuit.
- The valve plate is screwed together with the front side of the cylinder housing in the most widespread refrigerant piston compressors. For this purpose, bores are arranged both on the cylinder housing and also in the valve plate, the bores in the cylinder housing each being provided with a thread, via which the screw connection is performed. On the side of the valve plate opposite to the cylinder housing, in this most widespread type of refrigerant compressors, a cylinder cover is provided, which has a pressure chamber, in which compressed refrigerant expelled from the cylinder is briefly buffered in order to overflow into the refrigerant circuit thereafter. Exemplary embodiments are also known in which a suction chamber corresponding to the pressure chamber is provided, via which the refrigerant is suctioned through the suction opening into the cylinder. Pressure chamber and suction chamber are separated from one another by appropriate structural measures in the cylinder cover in such cases.
- A refrigerant compressor of conventional construction comprises an electric motor, which drives the piston oscillating in the piston bore via a crankshaft.
- To make the provision of a crankshaft superfluous, diverse linear compressor solutions exist, in which the piston is driven directly by an electric linear drive. In this case, the piston is connected to an oscillating body, which, enclosed by an exciter winding (also referred to as a stator) is set into movement in an oscillating manner along a piston longitudinal axis. The piston stroke (=piston travel) can be determined by a variably induced voltage on the linear drive.
- The exact delimitation of the piston travel during oscillation of the piston is problematic in such solutions. On the one hand, the piston is to be prevented from striking in the region of the top dead center on the cylinder head or on the valve plate arranged in the cylinder head. On the other hand, however, the top dead center of the piston is also to be prevented from being displaced too far downward, or the piston approaching the cylinder head or the valve plate is to be prevented from executing a reversal movement excessively early, thus resulting in a performance-reducing dead space.
- Mechanical spring elements for buffering the piston and therefore for delimiting the piston travel are proposed for this purpose in publications CN 101240793 A and
DE 10 2006 009 270 A. Changing the piston travel by means of adjustable spring elements is known fromDE 10 2006 009 256 A. - The disadvantage of such systems is mechanical wear in the spring elements and the piston components. The spring elements occupy valuable space and have proven to be inflexible if the refrigerating capacity of the refrigerant compressor or the piston stroke are to be changed.
- Linear compressors also exist in which the piston is exclusively held in position during its oscillation by an electronic controller of the linear drive. Such solutions for delimiting the piston travel, which are known, e.g., from WO 01/48379 A and WO 2009/103138 A2, are only implementable with provision of complex sensor and analysis technology, however. In particular, sensors are provided which ascertain the duration of a piston movement, which is compared thereafter by a microprocessor to a reference duration stored on a storage medium and the current position of the piston is calculated therefrom. Such systems are costly and are therefore hardly used in standard compressor manufacturing.
- The present invention is therefore based on the problem of proposing a simple and reliable possibility for delimiting the piston travel in refrigerant compressors having linear drive, which makes both provision of mechanical spring elements and also provision of complex sensor and control electronics for delimiting the piston travel superfluous. Dead space occurring in the cylinder housing is to be reduced as much as possible.
- These problems are solved according to the invention by a device having the characterizing features of
claim 1. - It is provided that the piston-cylinder unit is equipped with at least one permanent magnet arrangement, comprising respectively at least one first permanent magnet arranged on the piston or on a component connected to the piston and at least one second permanent magnet arranged on the cylinder housing or on a component connected to the cylinder housing, the first permanent magnet and the second permanent magnet respectively having the same magnetic pole direction to one another, in order to generate a repelling action between the two permanent magnets to delimit the piston travel in the region of the top dead center and/or in the region of the bottom dead center upon approach of the first permanent magnet to the second permanent magnet.
- The piston travel of the piston can be limited simply and reliably in this manner. Striking of the piston on elements of the cylinder housing, in particular on the valve plate, is also prevented without electronic sensor and control elements.
- Fundamentally, an arbitrary number of first and second permanent magnets can be arranged in arbitrary position and configuration.
- The component connected to the piston, on which the at least one first—movable—permanent magnet is arranged, can be the oscillating body or a piston shaft connecting the piston to the oscillating body in a special embodiment variant of the invention.
- The component connected to the cylinder housing, on or in which the at least one second—fixed—permanent magnet is arranged, is the cylinder head in a preferred embodiment variant of the invention.
- A valve plate can be arranged in the cylinder head, the at least one second permanent magnet being arranged on the valve plate, preferably being at least sectionally countersunk in the valve plate. In this way, the piston travel is delimited in the region of the top dead center. The second permanent magnet can be arranged both externally and also internally on or even entirely or partially in the valve plate. The delimitation of the piston travel in the bottom dead center can also be performed using permanent magnets, however, it can also be performed conventionally, for example, by means of spring elements.
- According to an alternative embodiment variant of the invention, the component connected to the cylinder housing, on or in which the at least one second permanent magnet is arranged, is a housing enclosing the oscillating body. This housing preferably is a support for the exciter winding (the stator) or the exciter winding itself.
- According to a particularly preferred embodiment variant of the invention, the at least one second permanent magnet is arranged inside the piston bore of the cylinder housing, in particular inside the working space or delimiting the working space. Thus, for example, one of the permanent magnets could be countersunk into the cylinder housing so that it delimits the working space using its front side. The working space is formed by the cylinder housing and designates the space within the cylinder housing which the piston passes through during its oscillation.
- As already mentioned, it would also be possible according to a further embodiment variant of the invention to arrange the second permanent magnet outside the piston bore or the working space.
- Of course, the at least one first permanent magnet can also be arranged outside the piston bore or the working space, e.g., as already proposed above, on the oscillating body or on the piston shaft.
- There can be provided a different or further permanent magnet arrangement, in order to delimit the piston travel alternatively or additionally in the region of the bottom dead center, the at least one second permanent magnet being arranged in an end region of the cylinder housing, the end region facing the cylinder head. It is sensible if the at least one first permanent magnet is arranged on a second front side of the piston facing away from the cylinder head or on a piston shaft.
- A particularly simple embodiment provides that the at least one first permanent magnet is arranged in the region of the first front side of the piston facing toward the cylinder head.
- To avoid dead space losses, it can be provided that—as already in the case of the second permanent magnets—the at least one first permanent magnet is sectionally or entirely countersunk in the front side and/or in the piston shaft. In particular, it is possible that the countersunk first and/or second permanent magnet is sheathed, preferably sheathed on all sides, by the material of the piston or the cylinder head or the valve plate.
- According to a refinement of the invention, it is provided that the permanent magnet is countersunk into the front side of the piston and/or the valve plate so that at least one free space, which communicates with the working space, is provided between permanent magnet and piston or permanent magnet and valve plate. This free space preferably extends along the entire periphery of the permanent magnet. The gap-shaped recess promotes free unfolding of the magnetic action of the permanent magnet or expansion of the magnetic field lines originating from the permanent magnet.
- Expansion of the magnetic field lines originating from the permanent magnet is promoted further in that the free space is implemented as a gap according to a preferred embodiment variant of the invention, whose clear opening width widens in the direction of the working space.
- The free space can be filled using a non-ferromagnetic material, such as plastic. Through such filling of the recess, undesired dead space (remaining space between piston and cylinder head or valve plate in the top dead center of the piston), which would decrease the performance of the refrigerant compressor, can be avoided.
- According to another preferred embodiment variant of the invention, the first permanent magnet arranged on the piston side is arranged opposite to the second permanent magnet arranged on the cylinder housing. For example, both permanent magnets can be arranged congruently in the piston longitudinal axis.
- For optimal pairing of the first permanent magnet arranged on the piston side and the second permanent magnet arranged on the cylinder housing side, measures according to the invention are proposed hereafter. In each case a focused action of the permanent magnets on one another and a stable location of the piston, in particular during its reversal movement at the dead centers, are to be ensured.
- The permanent magnets can be implemented as substantially cylindrical.
- In particular, the permanent magnets can be implemented as substantially ring-shaped, the ring shape preferably extending rotationally-symmetric to the piston longitudinal axis. The permanent magnets preferably have a ring-cylindrical shape in this case, so that countersunk permanent magnets can be enclosed by a free space in the form of a ring gap.
- The permanent magnets can also be arranged rotationally-symmetric to an axis which is parallel to the piston longitudinal axis.
- Arbitrary modifications to the ring shape are also possible, e.g., oval or elliptical shapes. Alternative embodiment variants would be, e.g., spiral-shaped or lattice-shaped permanent magnets. In a special embodiment variant, multiple permanent magnets are arranged concentrically around the piston longitudinal axis.
- If the front side of the at least one first permanent magnet arranged on the piston side extends substantially parallel to the front side of the at least one second permanent magnet arranged on the cylinder housing side, uniform implementation of the magnetic field is ensured.
- According to a further preferred embodiment variant of the invention, the first permanent magnet arranged on the piston side substantially has an equal field strength, therefore, in the case of identical material preferably a substantially equal mass, as the second permanent magnet arranged on the cylinder housing side. A symmetrical magnetic field is thus generated.
- A uniform magnetic field is also achieved if multiple permanent magnets are arranged on a circle extending concentrically to the piston longitudinal axis, the angle spacing of adjacent permanent magnets being substantially equal. The piston-side permanent magnets and the cylinder-housing-side permanent magnets are expediently respectively arranged on a circle, piston-side permanent magnets and cylinder-housing-side permanent magnets being diametrically opposite (i.e., being congruent viewed in the piston longitudinal axis).
- In a special type of construction, the piston can be implemented as a double piston, comprising two piston sections arranged on opposing end regions of the double piston, each forming one front side of the double piston. A first working space is formed between the first front side of the double piston and a first cylinder head comprising a first valve plate and a second working space is formed between the second front side of the double piston and a second cylinder head comprising a second valve plate. The oscillating body is arranged between the two front sides of the double piston, preferably enclosed by the double piston, an arrangement according to the invention of permanent magnets being provided for each cylinder head-piston section pair.
- In a method according to the invention for establishing the piston travel of a linear compressor in a refrigerant compressor according to the preamble of
claim 1, it is provided that the piston-cylinder unit is implemented according to one ofclaims 1 to 20 and in the case of predefined permanent magnets, the drive strength of the linear drive is set so that the piston changes its movement direction in a predefined top dead center and/or bottom dead center without using a mechanical spring element. - It can be provided, e.g., that the piston only changes its movement direction because of a permanent magnet arrangement in each case both at the top dead center and also at the bottom dead center. However, it can also be provided that the piston only changes its movement direction because of a permanent magnet arrangement in one dead center, while a known spring element is used for the change of the movement direction in the other dead center.
- With the permanent magnets, the piston forms a nonlinear mass-spring system jointly with the oscillating body and optionally the piston shaft. Different resonance frequencies are therefore possible in this mass-spring system if the full travel of the mass-spring system is not utilized, while in a linear mass-spring system, for example, in the case of exclusive use of spring elements, only one resonance frequency occurs, at which the piston is normally operated.
- Therefore, different piston frequencies and therefore different refrigerating capacities are possible according to the invention.
- Correspondingly, it can therefore be provided that—to achieve different refrigerating capacities—a specific frequency of the linear drive is additionally predefined.
- As an additional safety measure, so that the piston does not strike on the valve plate, it can be provided that the drive strength and/or frequency of the linear drive are set based on measured position data of the piston or magnetic field strengths. For this purpose, for example, Hall sensors as in inductive encoders or current-voltage measurements of the exciter winding can be used.
- The invention will be explained in greater detail on the basis of an exemplary embodiment. In the figures:
-
FIG. 1 shows a schematic view of a linear compressor according to the invention -
FIG. 2 shows a longitudinal section through a piston-cylinder unit according to the invention -
FIG. 3 shows a piston-cylinder unit according to the invention having a spring element -
FIG. 4 shows a piston-cylinder unit according to the invention having permanent magnets on the oscillating body of the linear drive -
FIG. 5 shows the embodiment variant according toFIG. 4 , the piston being located in its bottom dead center -
FIG. 6 shows a detail “B” fromFIG. 4 -
FIG. 7 shows a modification of the embodiment variant according toFIG. 4 with spring element -
FIG. 8 shows a schematic view of the magnetic fields developed in the region of the permanent magnets in the form of field lines (piston in bottom dead center) -
FIG. 9 shows a view as inFIG. 8 (piston on the path in the direction of top dead center) -
FIG. 10 shows a view as inFIG. 8 (piston reaches top dead center) -
FIG. 11 shows a force-distance diagram to illustrate the increase of the magnetic force upon approach of the first permanent magnet to the second permanent magnet -
FIG. 12 shows a piston-cylinder unit according to the invention having double piston -
FIG. 13 shows a schematic view of a linear compressor according to the invention arranged in a compressor housing. -
FIG. 1 schematically shows the construction of alinear compressor 23 according to the invention, which is arranged by means of asuspension device 28 within a hermetically sealed compressor housing 29 (shown inFIG. 13 ) of a small refrigerant compressor. Thelinear compressor 23 comprises a piston-cylinder unit 21 having at least onepiston 3 guided in apiston bore 2 of acylinder housing 1. Thecylinder housing 1 is frontally closed using acylinder head 4, more specifically using avalve plate 5 held in thecylinder head 4. - The
piston 3 is movable in an oscillating manner by alinear drive 6 along a pistonlongitudinal axis 9. In a known manner, thelinear drive 6 comprises anoscillating body 7, which is rigidly connected or articulated with thepiston 3, enclosed by an exciter winding (a stator) 8. In the present exemplary embodiment, theoscillating body 7 is connected by means of a piston rod or apiston shaft 22 to thepiston 3. - According to the invention, the piston-
cylinder unit 21 is equipped with at least one permanent magnet arrangement (namely two here: 11 a and 12 a; 11 b and 12 b), respectively comprising at least one firstpermanent magnet piston 3 or on a component connected to thepiston 3—in particular, this could be theoscillating body 7 or thepiston shaft 22 in this case—and comprising at least one secondpermanent magnet cylinder housing 1 or on a component connected to thecylinder housing 1. The at least one firstpermanent magnet permanent magnet permanent magnet 11 to the at least one secondpermanent magnet 12, a repelling effect arises between the twopermanent magnets piston 3. - In the case of
FIG. 1 , a firstpermanent magnet 11 a is attached to the front side of thepiston 3 and a further firstpermanent magnet 11 b, namely a ring-shaped permanent magnet, is attached to the opposing side. A secondpermanent magnet 12 a is attached to thecylinder head 4 or to its valve plate, and a furtherpermanent magnet 12 b is attached to the opposing side of thecylinder housing 1, where thepiston shaft 22 passes through thecylinder housing 1. The latter permanent magnet is implemented as ring-shaped. Thepermanent magnets piston 3, while thepermanent magnets piston 3. Depending on load, the points at which thepiston 3 actually reverses can vary. - An embodiment similar to that in
FIG. 1 is shown inFIG. 2 , except that inFIG. 2 a ring-shapedpermanent magnet 11 is countersunk in the firstfront side 3 a of thepiston 3 and a ring-shaped secondpermanent magnet 12 is countersunk corresponding thereto in thevalve plate 5 of thepiston 4. The surface of the firstpermanent magnet 11 facing toward the workingspace 14 is in a plane with the firstfront side 3 a of thepiston 3. The surface of the secondpermanent magnet 12 facing toward the workingspace 14 is in a plane with the level inner surface of thevalve plate 5. - The
valve plate 5 has asuction opening 17, which is closable on the inner side of thevalve plate 5 using asuction valve 15. Furthermore, it has a pressure opening 18, which can be closed on the outer side of thevalve plate 5 using apressure valve 16. - During the intake stroke shown here (the
piston 3 moves to the right), the refrigerant flows via thesuction opening 17 past theopen suction valve 15 into a workingspace 14 formed between thevalve plate 5 and a firstfront side 3 a of thepiston 3 facing toward it. During the compression stroke (thepiston 3 moves to the left), refrigerant is conveyed back out of the interior of thecylinder housing 1 via thepressure opening 18. Thepiston shaft 22 is not shown inFIG. 2 . - The two
permanent magnets piston 3 has the shape of a circular ring, as does the surface of thepermanent magnets space 14. - Both
permanent magnets piston 3 or thevalve plate 5, respectively, so that the surface of thepermanent magnet space 14 terminates level with the firstfront side 3 a of the piston or with the inner side of thevalve plate 5, respectively. Thepermanent magnets permanent magnets free space 13 is provided, so that the magnetic field lines—undisturbed by the metallic material of thepiston 3 or thevalve plate 5—can exit through the outer surface in the form of a cylindrical sheath of thepermanent magnets free space 13 can also, as shown in the case of thepiston 3, be filled using a non-ferromagnetic material, for example, using plastic. The dead space is thus decreased, i.e., the space between the piston in the dead center and the valve plate which can be filled with refrigerant. - The piston travel is delimited at the top dead center by the
permanent magnets FIG. 2 . To delimit the piston travel at the bottom dead center, either a further first permanent magnet, likepermanent magnet 11 b inFIG. 1 , can also be arranged on the secondfront side 3 b of thepiston 3, with a correspondingpermanent magnet 12 b on the cylinder housing. - Or, as shown in
FIG. 3 , aspring element 27 can be provided, which establishes the bottom dead center of thepiston 3. The embodiment of the piston-cylinder unit is equivalent to that ofFIG. 2 . In addition, the exciter winding 8 is also shown inFIG. 3 . - In the embodiment variant according to
FIGS. 4-6 , the firstpermanent magnets piston 3, but rather on the cylindricaloscillating body 7 of thelinear drive 6. The corresponding secondpermanent magnets housing 24 of thelinear drive 6, so that they align in the direction of the pistonlongitudinal axis 9 with thepermanent magnets - The
permanent magnets oscillating body 7 or thehousing 24, respectively, but rather are fastened on the circular surfaces of theoscillating body 7 or on opposing inner walls of thehousing 24, respectively. The ring cylinders are arranged concentrically to the pistonlongitudinal axis 9. - When the
piston 3 is located in the top dead center, seeFIG. 4 , thepermanent magnets longitudinal axis 9—have the least possible distance from one another because of the force of thelinear drive 6 acting on theoscillating body 7. However, thepermanent magnets piston 3. - If the
piston 3 is located in the bottom dead center, seeFIG. 5 , thepermanent magnets longitudinal axis 9—have the least possible distance from one another because of the force of thelinear drive 6 acting on theoscillating body 7. - However, the
permanent magnets piston 3. -
FIG. 6 shows detail B fromFIG. 4 in enlarged form. Thepermanent magnets permanent magnet 11 b is visible of the second permanent magnet arrangement (b). The radial external diameter of thepermanent magnets oscillating body 7, the diameter of thepermanent magnets oscillating body 7. -
FIG. 7 shows a modification of the embodiment variant according toFIG. 4 , in that the permanent magnet arrangement for establishing the bottom dead center fromFIG. 4 is replaced by aspring element 27. Thepermanent magnets FIG. 4 are maintained, thepermanent magnets spring element 27. -
FIG. 8 shows a schematic view of the magnetic fields developed in the region of thepermanent magnets FIGS. 2 and 3 in the form offield lines piston 3 being located in the region of its bottom dead center. Magnetic field lines are closed, they each exit at the so-called “north pole” from the permanent magnets and enter therein at the so-called “south pole”. When the south pole of a permanent magnet approaches the north pole of another permanent magnet, the permanent magnets attract and adhere to one another. If the north pole of one permanent magnet approaches the north pole of another permanent magnet (or the south pole approaches the south pole of another permanent magnet), the two permanent magnets repel, it is not possible or it is only possible using a specific force for the permanent magnets to approach close enough to one another so that their south poles touch. This principle is utilized in this invention. Since the repelling force between the magnetic poles of the same name is inversely proportional to the distance of the magnetic poles, the force for the approach of thepiston 3 to thevalve plate 5 is not linear to the distance betweenpiston 3 andvalve plate 5. This is a substantial difference from a spring element arranged betweenvalve plate 5 andpiston 3, in which the force is linearly dependent on the distance betweenvalve plate 5 andpiston 3. - Both
valve plate 5 and alsopiston 3 are manufactured in this exemplary embodiment from steel, i.e., they are ferromagnetic themselves, therefore themagnetic field lines valve plate 5 and thepiston 3. The distance betweenpiston 3 and piston bore 2 is shown exaggeratedly large here. -
FIG. 9 shows the piston-cylinder arrangement 21 during the progressing compression stroke, the piston is on the path in the direction of top dead center. The firstpermanent magnet 11 arranged on the firstfront side 3 a of thepiston 3 approaches the fixed secondpermanent magnet 12 countersunk in thevalve plate 5. The magnetic fields of the twopermanent magnets FIG. 8 . In the workingregion 14, the distance between theseparate field lines - According to
FIG. 10 , thepiston 3 has reached its top dead center. Striking of the firstfront side 3 a of thepiston 3 on thevalve plate 5 is prevented, since the twopermanent magnets piston 3 would be displaced to the right by the repelling force of thepermanent magnets - The piston travel in the region of the bottom dead center can also be delimited in the same fundamental way as the piston travel was delimited according to
FIGS. 8-10 in the region of the top dead center. -
FIG. 11 shows a force-distance graph to illustrate the increase of the magnetic force during the approach of the firstpermanent magnet 11 to the secondpermanent magnet 12. The distance between firstpermanent magnet 11 and secondpermanent magnet 12 in centimeters is plotted on the horizontal axis, the magnetic force F in % is plotted on the vertical axis, 100% representing the repelling magnetic force in the top dead center. This force must be applied by thelinear drive 6 and the mass inertia of thepiston 3 havingoscillating body 7 to hold thepiston 3 for a short time in the top dead center. In this example, the top dead center is given at a distance of 0.05-0.5 mm between firstpermanent magnet 11 and secondpermanent magnet 12. Both the rhomboid measuring points and also the measuring curve interpolated based on the measuring points are shown. -
FIG. 12 shows a piston-cylinder unit according to the invention having a double piston. Thepiston 3 is implemented as a double piston and comprises twopiston sections front side space 14 is formed between the firstfront side 3 a of the double piston and afirst cylinder head 4 comprising afirst valve plate 5, and asecond working space 14′ is formed between the secondfront side 3 b of the double piston and asecond cylinder head 4′ comprising asecond valve plate 5′. Theoscillating body 7 is arranged between the twofront sides double piston 3. Onepermanent magnet arrangement piston section pair 4/19 or 4′/20. - 1 cylinder housing
- 2 piston bore
- 3 piston
- 3 a first front side of the piston
- 3 b second front side of the piston
- 4 cylinder head
- 4′ second cylinder head
- 5 valve plate
- 5′ second valve plate
- 6 linear drive
- 7 oscillating body
- 8 exciter winding (stator)
- 9 piston longitudinal axis
- 11, 11 a, 11 b first permanent magnet
- 12, 12 a, 12 b second permanent magnet
- 13 free space
- 14 working space of the
piston 3 - 14′ second working space of the
piston 3 - 15 suction valve
- 15′ second suction valve
- 16 pressure valve
- 16′ second pressure valve
- 17 suction opening
- 17′ second section opening
- 18 pressure opening
- 18′ second pressure opening
- 19 first piston section of the double piston
- 20 second piston section of the double piston
- 21 piston-cylinder unit
- 22 piston shaft
- 23 linear compressor
- 24 housing of the linear drive
- 25 field lines of the first permanent magnet
- 26 field lines of the second permanent magnet
- 27 spring element
Claims (15)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ATGM790/2009 | 2009-12-14 | ||
AT0079009U AT12038U1 (en) | 2009-12-14 | 2009-12-14 | REFRIGERANT COMPRESSOR WITH LINEAR ACTUATOR |
PCT/AT2010/000478 WO2011079330A1 (en) | 2009-12-14 | 2010-12-14 | Coolant compressor with linear drive |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130034456A1 true US20130034456A1 (en) | 2013-02-07 |
Family
ID=44246906
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/515,583 Abandoned US20130034456A1 (en) | 2009-12-14 | 2010-12-14 | Refrigerant compressor having linear drive |
Country Status (5)
Country | Link |
---|---|
US (1) | US20130034456A1 (en) |
EP (1) | EP2513479B1 (en) |
CN (1) | CN102741551A (en) |
AT (1) | AT12038U1 (en) |
WO (1) | WO2011079330A1 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130336809A1 (en) * | 2012-06-19 | 2013-12-19 | Hilti Aktiengesellschaft | Fastener-driving device and controlling method |
US9145878B1 (en) * | 2014-07-11 | 2015-09-29 | Marvin Ray McKenzie | Oscillating linear compressor |
US20170113337A1 (en) * | 2015-10-22 | 2017-04-27 | Caterpillar Inc. | Piston and Magnetic Bearing for Hydraulic Hammer |
US20170122305A1 (en) * | 2015-11-04 | 2017-05-04 | General Electric Company | Method for Operating A Linear Compressor |
US10208741B2 (en) | 2015-01-28 | 2019-02-19 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US10502201B2 (en) | 2015-01-28 | 2019-12-10 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US10641263B2 (en) | 2017-08-31 | 2020-05-05 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US10670008B2 (en) | 2017-08-31 | 2020-06-02 | Haier Us Appliance Solutions, Inc. | Method for detecting head crashing in a linear compressor |
US10830230B2 (en) | 2017-01-04 | 2020-11-10 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8714946B2 (en) | 2012-09-13 | 2014-05-06 | General Electric Company | Linear compressor with an electro-magnetic spring |
DE102014205209A1 (en) * | 2014-03-20 | 2015-09-24 | Robert Bosch Gmbh | Linear drive, piston pump arrangement |
CN107061221B (en) * | 2017-01-24 | 2020-03-31 | 青岛海尔智能技术研发有限公司 | Linear compressor |
CN108194312A (en) * | 2018-01-29 | 2018-06-22 | 东莞市卓奇电子科技有限公司 | Permanent magnetism oscillator piston component, asynchronous push-pull type Electromagnetic Vibrator compressor and asynchronous double-push-pull type Electromagnetic Vibrator compressibility |
CN114233719A (en) * | 2021-11-30 | 2022-03-25 | 江苏龙城鸿辉液压机电有限公司 | Buffer structure of ultra-large hydraulic hoist |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SU1312246A2 (en) * | 1984-04-13 | 1987-05-23 | Грузинский политехнический институт им.В.И.Ленина | Electromagnetic machine |
CN2119514U (en) * | 1991-11-14 | 1992-10-21 | 臧立华 | Electricity-saving magnetic compressor |
DE19504751A1 (en) * | 1995-02-03 | 1996-08-08 | Werner Sommer | Magnet pump for liquid and gas media |
WO1998001675A1 (en) * | 1996-07-09 | 1998-01-15 | Sanyo Electric Co., Ltd. | Linear compressor |
JP2002542428A (en) * | 1999-04-19 | 2002-12-10 | ライボルト ヴァークウム ゲゼルシャフト ミット ベシュレンクテル ハフツング | Oscillating piston drive |
BR9907432B1 (en) | 1999-12-23 | 2014-04-22 | Brasil Compressores Sa | COMPRESSOR CONTROL METHOD, PISTON POSITION MONITORING SYSTEM AND COMPRESSOR |
DE10314007A1 (en) * | 2003-03-28 | 2004-10-07 | Leybold Vakuum Gmbh | Piston vacuum pump for pumping gas, has sensor that detects speed of switching supply of energizing current between electrical coils by magnet arrangement |
DE102006009256A1 (en) | 2006-02-28 | 2007-08-30 | BSH Bosch und Siemens Hausgeräte GmbH | Compressor apparatus for household cooling equipment e.g. refrigerator, freezer has linear drive having adjustable rotor zero position, and linear compressor having adjustable piston zero position |
DE102006009270A1 (en) | 2006-02-28 | 2007-08-30 | BSH Bosch und Siemens Hausgeräte GmbH | Linear compressor for cooling equipment e.g. refrigerator, freezer has linkage having spring, and which couples compressor piston to drive |
BRPI0800251B1 (en) | 2008-02-22 | 2021-02-23 | Embraco Indústria De Compressores E Soluções Em Refrigeração Ltda | linear compressor control system and method |
CN101240793B (en) | 2008-03-14 | 2011-04-27 | 刘新春 | Linear motor double cylinder compression pump |
-
2009
- 2009-12-14 AT AT0079009U patent/AT12038U1/en not_active IP Right Cessation
-
2010
- 2010-12-14 WO PCT/AT2010/000478 patent/WO2011079330A1/en active Application Filing
- 2010-12-14 CN CN2010800626814A patent/CN102741551A/en active Pending
- 2010-12-14 EP EP10807312.3A patent/EP2513479B1/en active Active
- 2010-12-14 US US13/515,583 patent/US20130034456A1/en not_active Abandoned
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130336809A1 (en) * | 2012-06-19 | 2013-12-19 | Hilti Aktiengesellschaft | Fastener-driving device and controlling method |
US9145878B1 (en) * | 2014-07-11 | 2015-09-29 | Marvin Ray McKenzie | Oscillating linear compressor |
US10208741B2 (en) | 2015-01-28 | 2019-02-19 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US10502201B2 (en) | 2015-01-28 | 2019-12-10 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US20170113337A1 (en) * | 2015-10-22 | 2017-04-27 | Caterpillar Inc. | Piston and Magnetic Bearing for Hydraulic Hammer |
US10190604B2 (en) * | 2015-10-22 | 2019-01-29 | Caterpillar Inc. | Piston and magnetic bearing for hydraulic hammer |
US20170122305A1 (en) * | 2015-11-04 | 2017-05-04 | General Electric Company | Method for Operating A Linear Compressor |
US10174753B2 (en) * | 2015-11-04 | 2019-01-08 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US10830230B2 (en) | 2017-01-04 | 2020-11-10 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US10641263B2 (en) | 2017-08-31 | 2020-05-05 | Haier Us Appliance Solutions, Inc. | Method for operating a linear compressor |
US10670008B2 (en) | 2017-08-31 | 2020-06-02 | Haier Us Appliance Solutions, Inc. | Method for detecting head crashing in a linear compressor |
Also Published As
Publication number | Publication date |
---|---|
WO2011079330A1 (en) | 2011-07-07 |
CN102741551A (en) | 2012-10-17 |
EP2513479A1 (en) | 2012-10-24 |
AT12038U1 (en) | 2011-09-15 |
EP2513479B1 (en) | 2015-08-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US20130034456A1 (en) | Refrigerant compressor having linear drive | |
KR101718039B1 (en) | Reciprocating compressor | |
US10876524B2 (en) | Linear compressor | |
KR101681588B1 (en) | Linear compressor | |
KR20090105471A (en) | Receprocating motor and receprocating compressor having the same | |
JP3762469B2 (en) | Linear compressor drive unit | |
KR101495188B1 (en) | Reciprocating compressor | |
JP4444285B2 (en) | Hermetic compressor | |
KR100724842B1 (en) | Hermetic compressor | |
JP2001251836A (en) | Drive with linear motor | |
JP2001218441A (en) | Magnetic field shield structure and drive having linear motor | |
BR102016025273B1 (en) | COMPRESSOR | |
JP3475132B2 (en) | Driving device with magnetic shielding structure and linear motor | |
JP2001214858A (en) | Driving device having linear motor | |
KR20050111097A (en) | Linear compressor having a sensor | |
JPH11132585A (en) | Oscillatory compressor | |
US20190078563A1 (en) | Linear compressor | |
KR20180093432A (en) | Linear compressor | |
US11434886B2 (en) | Linear compressor and method for controlling the same | |
JP2002070734A (en) | Linear compressor | |
KR100428508B1 (en) | Compressor and control method of compressor | |
KR100320203B1 (en) | Apparatus for supporting moving mass in linear compressor | |
JP2003307181A (en) | Variable capacity type refrigerant compressor with swash plate | |
KR20040082199A (en) | Linear compressor | |
JP2000023441A (en) | Linear motor and linear compressor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: ACC AUSTRIA GMBH, AUSTRIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SCHOEGLER, HANS PETER;REEL/FRAME:028503/0514 Effective date: 20120626 |
|
AS | Assignment |
Owner name: SECOP AUSTRIA GMBH, AUSTRIA Free format text: CHANGE OF ADDRESS;ASSIGNOR:SECOP AUSTRIA GMBH;REEL/FRAME:032447/0729 Effective date: 20140118 Owner name: SECOP AUSTRIA GMBH, AUSTRIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ACC AUSTRIA GMBH;REEL/FRAME:032436/0111 Effective date: 20131220 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |