JP5493388B2 - Reciprocating motor - Google Patents

Description

  The present invention relates to a reciprocating motor.

  Conventionally, a reciprocating motor is known. The reciprocating motor includes a housing having a compression chamber for sucking and compressing the working fluid of the refrigeration cycle system and a working chamber provided separately from the compression chamber, and a housing that is reciprocally movable in the longitudinal direction. A drive shaft provided in the working chamber; a piston provided on the drive shaft so as to face the compression chamber; and a housing for sucking and compressing a working fluid of the refrigeration cycle system in the compression chamber as the drive shaft reciprocates. A permanent magnet provided in the working chamber, a coil provided in the working chamber of the housing and supplied with power, and a magnetic yoke that forms a magnetic path for reciprocating the drive shaft by the coil and the permanent magnet (Patent) References 1, 2).

JP 2003-185282 A JP 2006-2708 A

  According to the above-described conventional technology, the coil disposed in the coil chamber generates heat due to Joule heat accompanying power feeding. When the driving time of the motor becomes long, the coil chamber is gradually heated. For this reason, the temperature of the coil is further increased, the electric resistance of the coil is further increased, and the motor efficiency may be lowered.

  The present invention has been made in view of the above circumstances, and a reciprocating motor that can suppress overheating of a coil chamber, suppress overheating of a coil disposed in the coil chamber, and improve motor efficiency. The issue is to provide.

  The reciprocating motor of the present invention includes (i) a housing having a working chamber, (ii) a driving shaft provided in the working chamber of the housing so as to be capable of reciprocating in the longitudinal direction, and (iii) driving provided on the driving shaft. A movable body that reciprocates with the reciprocating movement of the shaft; (iv) a permanent magnet provided in the working chamber of the housing; and (v) provided to move relative to the permanent magnet and disposed in the working chamber of the housing. And (vi) a magnetically permeable yoke formed of a magnetically permeable material formed by a coil and a permanent magnet, and (v) a magnetically permeable yoke. Has a coil chamber in which the coil is disposed, and a through hole that allows the inside of the coil chamber to communicate with the outside of the coil chamber, and discharges the fluid inside the coil chamber to the outside of the coil chamber through the through hole. It is characterized by letting

  When power is supplied to the coil, a Lorentz force generated by a current flowing through the coil and a magnetic field formed by the permanent magnet and the magnetically permeable yoke is generated. As a result, the drive shaft reciprocates together with the piston. When power is supplied to the coil, the coil generates Joule heat and is heated. The temperature of the coil chamber in which the coil is disposed is also increased. As a result, the heat accumulated in the coil chamber can move to the outside of the coil chamber together with the fluid through the through hole of the magnetically permeable yoke. For this reason, overheating of the coil chamber is suppressed, and overheating of the coil disposed in the coil chamber is suppressed.

  According to the present invention, the fluid having the heat in the coil chamber can move to the outside of the coil chamber through the through hole of the magnetically permeable yoke. For this reason, overheating of the coil chamber is suppressed, and overheating of the coil disposed in the coil chamber is suppressed. As described above, since overheating of the coil disposed in the coil chamber of the magnetically permeable yoke is suppressed, the temperature rise of the coil is suppressed and the motor efficiency can be improved.

It is sectional drawing of the motor which concerns on Example 1 and is cut | disconnected along the axial length direction. It is sectional drawing of the motor which concerns on Example 2 and is cut | disconnected along the axial length direction. FIG. 10 is an end view showing a magnetically permeable yoke according to a third embodiment and having a first through hole and a second through hole. FIG. 10 is an end view showing a magnetically permeable yoke according to a fourth embodiment and having a first through hole and a second through hole. FIG. 10 is a cross-sectional view of a motor according to Embodiment 5 that is cut along the axial length direction. FIG. 10 is a cross-sectional view of a motor according to Embodiment 6 that is cut along the axial length direction. FIG. 10 is a cross-sectional view of a magnetically permeable yoke having a second through hole cut along a direction perpendicular to the axis according to the seventh embodiment. FIG. 16 is a cross-sectional view of a motor according to Embodiment 10 which is cut along an axial length direction. FIG. 16 is a cross-sectional view of a motor according to Embodiment 11 that is cut along the axial length direction. FIG. 16 is a cross-sectional view of a motor according to Embodiment 12 which is cut along an axial length direction. FIG. 20 is a cross-sectional view of a motor according to Embodiment 13 that is cut along an axial length direction. FIG. 17 is a cross-sectional view of a motor according to Embodiment 14 which is cut along the axial length direction.

  The coil is provided to move relative to the permanent magnet. In this case, the coil may be movable and the permanent magnet may be fixed. Alternatively, the permanent magnet may be movable and the coil may be fixed.

  According to one aspect of the present invention, the magnetically permeable yoke is made of a magnetically permeable material that transmits magnetic flux, and has an inner yoke portion arranged around the axis of the drive shaft and an axis around the axis of the drive shaft. An outer yoke part that covers the inner yoke part via the coil chamber, an intermediate yoke part that connects an end part in the axial length direction of the outer yoke part and an end part in the axial length direction of the inner yoke part, an inner yoke part, And a coil chamber formed by an outer yoke portion and an intermediate yoke portion. In this case, the through hole is formed in the intermediate yoke portion so as to penetrate the intermediate yoke portion and to face the coil chamber. Since the through hole faces the coil chamber, the fluid having heat in the coil chamber can be discharged to the outside of the coil chamber through the through hole. Examples of the fluid include gas (for example, refrigerant gas, air).

  According to one aspect of the present invention, in a cross section along the axis of the magnetically permeable yoke, one side of the through hole that is closer to the coil chamber is one end, and the other side of the through hole is the other end. At this time, the flow passage cross-sectional area of the through hole is larger at the one end than at the other end, and smaller at the other end than at one end. In this case, it is advantageous to form a unidirectional flow of fluid in the working chamber.

  According to one aspect of the present invention, a check valve that allows a unidirectional flow of fluid in the through hole and prevents a reverse flow is provided in the through hole. In this case, it is advantageous to form a unidirectional flow of fluid in the working chamber.

  According to one aspect of the present invention, the magnetically permeable yoke includes an inner yoke portion arranged around the axis of the drive shaft, and covers the inner yoke portion arranged around the axis of the drive shaft via the coil chamber. A coil formed of an outer yoke portion, an intermediate yoke portion connecting an end portion in the axial length direction of the outer yoke portion and an end portion in the axial length direction of the inner yoke portion, and an inner yoke portion, an outer yoke portion, and an intermediate yoke portion And a chamber. In this case, the through hole has a first through hole formed in the intermediate yoke portion and penetrating the intermediate yoke portion, and a second through hole formed in the outer yoke portion and penetrating the outer yoke portion.

  According to one aspect of the present invention, a cooling element that cools the fluid by exchanging heat with the fluid in the working chamber is provided in the working chamber. It is advantageous for cooling the fluid in the working chamber. Any cooling element may be used as long as it can cool the fluid in the working chamber, and examples thereof include a radiator, a heat exchanger, and a cold head.

  According to one aspect of the present invention, there is provided a blower that increases the amount of fluid passing through the through hole by blowing fluid to the through hole as the drive shaft reciprocates. Since the amount of fluid passing through the through hole is increased, it is advantageous for suppressing the temperature rise of the magnetically permeable yoke and the coil chamber.

  Embodiment 1 of the present invention will be described below with reference to FIG. The reciprocating motor of this embodiment is also called a voice coil motor, and is used as a compression process of the refrigeration cycle system 9 that is an operating system. This motor has a box-shaped housing 1, a drive shaft 2, a piston 3 as a movable body, a coil 4, a magnetically permeable yoke 5, and a permanent magnet 6. The housing 1 includes a cylinder 10 that forms a compression chamber 11 for sucking and compressing a working fluid (refrigerant gas) of a refrigeration cycle system 9 that is an operation system, and an operation provided separately from the compression chamber 11. It has a chamber 12. The housing 1 includes an outer wall 13 having a cylindrical shape and an end wall 14 formed at an end portion of the outer wall 13 in the axial length direction.

  The working chamber 12 is independent of the compression chamber 11 for performing the compression stroke of the refrigeration cycle system 9, but contains the same fluid as the working fluid of the refrigeration cycle system 9. This is for avoiding the mixing of gases having different compositions into the working fluid of the compression chamber 11. For example, when the working fluid of the refrigeration cycle system 9 is helium, helium gas is accommodated in the working chamber 12. When the working fluid of the refrigeration cycle system 9 is nitrogen, nitrogen gas is accommodated in the working chamber 12.

  The drive shaft 2 is of a horizontal axis type with its axis P1 extending in the horizontal direction, and is provided in the working chamber 12 of the housing 1 so as to be able to reciprocate in the longitudinal direction (arrow X direction). The drive shaft 2 is supported by a first bearing 21 and a second bearing 22. The first bearing 21 supports the tip end side of the drive shaft 2 and faces the piston 3. The second bearing 22 supports the base end side of the drive shaft 2 and faces the end wall 14 of the housing 1. The first bearing 21 and the second bearing 22 are formed of flexure bearings, have a spiral shape, and have a spiral opening. The first bearing 21 and the second bearing 22 have low rigidity in the direction along the axis P1, but have high rigidity in the direction orthogonal to the axis P1.

  In the axial direction, the working chamber 12 includes a first working chamber 12f that exists between the piston 3 and the magnetically permeable yoke 5, and a second working chamber 12s that exists between the magnetically permeable yoke 5 and the end wall 14. And a main working chamber 12t in which the permeable yoke 5 is disposed. Since the first bearing 21 and the second bearing 22 are formed of a spiral flexure bearing having air permeability, the first working chamber 12f, the main working chamber 12t, and the second working chamber 12s communicate with each other. .

  The piston 3 has a front surface 3 f that faces the compression chamber 11 and a back surface 3 r that faces away from the compression chamber 11, and is provided at the tip of the drive shaft 2. The piston 3 sucks and compresses the working fluid in the refrigeration cycle system 9 in the compression chamber 11 as the drive shaft 2 reciprocates. The permanent magnet 6 is provided in the working chamber 12 of the housing 1. The permanent magnet 6 has a cylindrical shape or a cylindrical shape divided in the radial direction, and the outer peripheral surface 61 and the inner peripheral surface 62 of the permanent magnet 6 in the radial direction are different magnetic poles.

  The coil 4 has a cylindrical shape around the axis P1 and is provided in the main working chamber 12t of the working chamber 12 of the housing 1. When an alternating current is supplied to the coil 4, the coil 4 receives an external magnetic field. Create Lorentz force. Since the coil 4 is attached to the drive shaft 2 with a cylindrical fixture 23, when the coil 4 reciprocates in the directions of arrows X1 and X2, the drive shaft 2 reciprocates in the same direction. The fixture 23 may have an arm structure.

  The permeable yoke 5 is made of a permeable material that transmits magnetic flux. Examples of the magnetically permeable material include iron. As the iron system, pure iron system, silicon steel sheet system, ferritic casting, ferritic cast steel and the like are excited. The magnetically permeable yoke 5 may be a laminated body obtained by laminating thin plates in the thickness direction thereof, or may be a bulk body in which an aggregate of iron-based powder particles is consolidated with a binder such as a resin binder. Alternatively, it may be a bulk body formed of a ferritic cast or ferritic cast steel. Ferrite means alpha iron.

  The permeable yoke 5 is provided in the main working chamber 12 t of the working chamber 12 of the housing 1. The magnetically permeable yoke 5 is disposed substantially coaxially around the axis P1 of the drive shaft 2 and the inner yoke portion 54 having a cylindrical shape that is disposed approximately coaxially around the axis P1 of the drive shaft 2. An outer yoke portion 55 having a cylindrical shape that is disposed and covers the inner yoke portion 54 via the coil chamber 50, and an axial end portion of the outer yoke portion 55 and an end portion of the inner yoke portion 54 in the axial length direction. It has an intermediate yoke portion 56 connected along a right angle direction (radial direction of the magnetically permeable yoke 5), and a coil chamber 50 having a cylindrical shape formed by the inner yoke portion 54, the outer yoke portion 55, and the intermediate yoke portion 56. The permeable yoke 5 has a coil chamber 50 in which the coil 4 is disposed, and a plurality of through holes 51 that communicate with the coil chamber 50 so as to release the heat of the coil chamber 50 to the outside of the coil chamber 50.

  As shown in FIG. 1, since the coil chamber 50 faces the intermediate yoke portion 56, one end side of the coil chamber 50 on the compression chamber 11 side is closed. It is preferable that the outer wall surface 55s of the outer yoke portion 55 is in contact with the inner wall surface 13i of the outer wall 13 of the housing 1 so that heat can be transferred. This is to improve the heat dissipation of the outer yoke portion 55 of the permeable yoke 5. However, in some cases, a minute gap may be interposed between the outer wall surface 55 s of the outer yoke portion 55 and the inner wall surface 13 i of the outer wall 13 of the housing 1. The inner yoke portion 54 has a shaft hole 53 through which the drive shaft 2 is inserted. The inner wall surface 53 a of the shaft hole 53 is maintained in non-contact with the drive shaft 2.

  A permanent magnet 6 arranged in a cylindrical shape or in a cylindrical shape is coaxially fixed to the inner peripheral portion of the outer yoke portion 55 of the permeable yoke 5. The coil 4 is disposed in the coil chamber 50 of the permeable yoke 5, and is disposed substantially coaxially between the inner yoke portion 54 and the permanent magnet 6 in the radial direction of the permeable yoke 5.

  In this case, as shown in FIG. 1, the through hole 51 is formed so as to penetrate the intermediate yoke portion 56 in the intermediate yoke portion 56 of the magnetically permeable yoke 5. The through hole 51 penetrates along a direction parallel to the axis P1 of the drive shaft 2. As shown in FIG. 1, since the length L1 of the through hole 51 corresponds to the thickness of the intermediate yoke portion 56, the length L1 is short, the pressure loss is small, and the flow rate of fluid passing therethrough is ensured.

  The intermediate yoke portion 56 faces the coil chamber 50. Therefore, the fluid having heat in the coil chamber 50 passes through the through hole 51 and is discharged to the outside of the coil chamber 50 (specifically, the first working chamber 12f). Since the through-hole 51 faces the compression chamber 11 and the back surface 3r of the piston 3 via the first bearing 21, when the piston 3 reciprocates in the directions of the arrows X1 and X2, the influence of gas movement caused by the reciprocating movement. It is easy to receive.

  According to the present embodiment, the cross section in a direction perpendicular to the axis P1 of the drive shaft 2 may be used, and the through hole 51 may have a perfect circle shape, or in the radial direction (arrow D direction) of the permeable yoke 5. An elliptical shape extending along the slit or a slit extending along the radial direction (arrow D direction) of the permeable yoke 5 may be used. If the ellipse shape and the slit shape are used, an advantage that the magnetic path of the magnetic flux can be obtained satisfactorily in the permeable yoke 5 is obtained.

  When an alternating current is supplied to the coil 4, a Lorentz force that causes the drive shaft 2 having the coil 4 to reciprocate along the axis P1 by a magnetic field formed by the permanent magnet 6 and the permeable yoke 5. Is generated in the coil 4. As a result, the drive shaft 2 reciprocates together with the piston 3 in the directions of the arrows X1 and X2. If the drive shaft 2 moves together with the piston 3 in one direction (arrow X1 direction), the piston 3 performs a working fluid suction step in the compression chamber 11. When the drive shaft 2 moves together with the piston 3 in the other direction (arrow X2 direction), the piston 3 performs a working fluid compression process in the compression chamber 11. Thus, the piston 3 repeats the working fluid suction process and the compression process of the refrigeration cycle system 9.

  When the motor is driven, that is, when an alternating current is supplied to the coil 4, the coil 4 is gradually heated to generate Joule heat. If the through hole 51 is not formed, the coil chamber 50 in which the coil 4 is disposed is also heated. In particular, since the coil chamber 50 is surrounded by the inner yoke portion 54, the outer yoke portion 55, and the intermediate yoke portion 56, the temperature is easily increased. Further, the temperature of the permanent magnet 6 in the coil chamber 50 is also raised.

  When the piston 3 moves in the direction of the arrow X2 (compression direction) together with the drive shaft 2 to perform the compression process, the volume of the first working chamber 12f increases and the pressure in the first working chamber 12f decreases and is reduced. Further, the coil 4 in the coil chamber 50 also moves in the direction of the arrow X2. For this reason, the fluid warmed by the Joule heat of the coil 4 in the coil chamber 50 passes through the through hole 51 from the coil chamber 50 and is discharged from the coil chamber 50 toward the first working chamber 12f, and the first working chamber 12f. Cooled.

  On the other hand, when the piston 3 moves in the direction of the arrow X1 (suction direction) together with the drive shaft 2 to perform the suction process, the volume of the first working chamber 12f decreases and the pressure in the first working chamber 12f increases. Increased pressure. Furthermore, the coil 4 in the coil chamber 50 also moves in the direction of the arrow X1. For this reason, it is considered that the fluid cooled in the first working chamber 12 f flows from the first working chamber 12 f through the through hole 51 to the coil chamber 50.

  As described above, according to the present embodiment, the heat of the coil chamber 50 generated based on the Joule heat by the power supply to the coil 4 passes through the through hole 51 of the magnetically permeable yoke 5 and the outside of the coil chamber 50. It can move quickly to (first working chamber 12f). For this reason, overheating of the coil chamber 50 is suppressed, and overheating of the coil 4 disposed in the coil chamber 50 is suppressed. In particular, as shown in FIG. 1, since the end 4e of the coil 4 faces the through hole 51, the cylindrical coil 4 is linked to the drive shaft 2 in the coil chamber 50 in the direction of the arrow X2. The end 4e of the coil 4 easily pushes the fluid heated in the coil chamber 50 in the direction of the arrow X2 and discharges the fluid from the through hole 51 to the first working chamber 12f. Further, when the coil 4 moves in the direction of the arrow X1 in the coil chamber 50 in conjunction with the drive shaft 2, it is considered that the fluid cooled in the first working chamber 12f can easily flow into the coil chamber 50 from the through hole 51. Thus, the coil 4 can perform a pumping action on the fluid in the coil chamber 50.

  Further, when the coil 4 is made of metal, when the coil 4 is heated, the electrical resistance of the coil 4 increases, so that the Joule heat tends to increase. As described above, according to the present embodiment, the heat of the coil chamber 50 generated based on the Joule heat by the power supply to the coil 4 passes through the through hole 51 of the magnetically permeable yoke 5 to the outside of the coil chamber 50. Can move quickly. For this reason, overheating of the coil chamber 50 is suppressed. As a result, overheating of the coil 4 disposed in the coil chamber 50 is suppressed, and the electrical resistance of the coil 4 is kept low. Therefore, Joule heat based on an increase in electrical resistance is suppressed, and the power for driving the motor can be saved. Furthermore, since the overheating of the permanent magnet 6 disposed inside the coil chamber 50 is also suppressed, it is possible to contribute to securing the magnetic force of the permanent magnet 6 and improving the durability.

  When the through-hole 51 is not formed in the magnetically permeable yoke 5, the coil 4 is overheated by Joule heat accompanying power feeding, and thus there is a possibility that the temperature becomes 100 ° C. or 200 ° C. or higher in some cases.

  In the present embodiment, when the piston 3 moves in the arrow X1 direction so as to increase the volume of the compression chamber 11 and the piston 3 performs the suction process, the working fluid of the refrigeration cycle system 9 is sucked into the compression chamber 11. Furthermore, when the piston 3 moves in the direction of the arrow X2 so as to reduce the volume of the compression chamber 11 and the piston 3 performs the compression process of compressing the working fluid in the compression chamber 11, the working fluid in the compression chamber 11 is The piston 3 is compressed by the front surface 3f of the piston 3 and is heated by compression heat. The coil chamber 50 of the housing 1 is independent of such a working fluid flow path. Thus, in this embodiment, the compression chamber 11 functions to suck and compress the working fluid as the piston 3 reciprocates. The coil chamber 50 of the housing 1 is separated in distance from the compression chamber 11 that performs such a function, and the independence of the coil chamber 50 with respect to the refrigeration cycle system 9 is high. Thus, the present embodiment is not intended to positively supply the fluid heated by the heat of the coil 4 from the coil chamber 50 to the compression chamber 11 through the first through hole 51.

  According to Patent Document 2 described above, a coil chamber is incorporated in the refrigeration cycle system 9, and the coil chamber is arranged in the working fluid flow path itself toward the compression chamber. Therefore, after the fluid heated by the heat of the coil is discharged from the coil chamber, it is actively sucked into the compression chamber by the piston suction action and compressed by the piston compression action. For this reason, since the working fluid heated by receiving heat from the coil in the coil chamber is compressed after being sucked in the compression chamber, the combined heat received from the coil and the compression heat in the compression chamber are discharged from the compression chamber. The temperature of the working fluid is likely to be high, which is not preferable for the refrigeration cycle.

  FIG. 2 shows a second embodiment. The present embodiment basically has the same configuration and the same function and effect as the first embodiment. As shown in FIG. 2, the magnetically permeable yoke 5 includes an inner yoke portion 54 disposed around the axis P <b> 1 of the drive shaft 2, and an inner yoke portion 54 disposed around the axis P <b> 1 of the drive shaft 2. An outer yoke portion 55 that is covered through the chamber 50, an intermediate yoke portion 56 that connects one end portion in the axial length direction of the outer yoke portion 55 and one end portion in the axial length direction of the inner yoke portion 54, an inner yoke portion 54, and an outer yoke portion And a coil chamber 50 formed by a yoke portion 55 and an intermediate yoke portion 56.

  In this case, as shown in FIG. 2, the through hole is formed in the intermediate yoke portion 56 and is formed in the first through hole 51 passing through the intermediate yoke portion 56 along the axial length direction and the outer yoke portion 55. And a second through hole 52 penetrating the portion 55 along the axial length direction. Since the length L1 of the first through hole 51 corresponds to the thickness of the intermediate yoke portion 56, it is short and has little pressure loss. Since the length L2 of the second through hole 52 corresponds to the axial length of the outer yoke portion 55, it is longer than the length L1 of the first through hole 51.

  As can be understood from FIG. 2, the first through hole 51 and the second through hole 52 are opposed to the back surface 3r of the piston 3 through the first bearing 21 having air permeability. It is easy to be affected by the pressure fluctuation of the first working chamber 12f caused by it.

  The through holes 51 and 52 may have a perfect circle shape in a cross section in a direction orthogonal to the axis P1 of the drive shaft 2, or may be an oval shape extending along the radial direction (arrow R direction) of the magnetically permeable yoke 5. Alternatively, a slit shape extending along the radial direction (arrow R direction) of the magnetically permeable yoke 5 may be used. If it is an ellipse shape and a slit shape, the advantage that the magnetic path of magnetic flux will be acquired favorably is acquired. Here, when the cross-sectional area of the first through-hole 51 is S1, and the cross-sectional area of the second through-hole 52 is S2, S1 = S2, S1≈S2, or S1 <S2 However, S1> S2 may be sufficient.

  As in the first embodiment, when an alternating current is supplied to the coil 4, a Lorentz that reciprocates the drive shaft 2 along its axis P1 by a magnetic field formed by the permanent magnet 6 and the permeable yoke. A force is generated in the coil 4. As a result, the drive shaft 2 reciprocates together with the piston 3 in the directions of the arrows X1 and X2. If the drive shaft 2 moves in one direction (in the direction of the arrow X1) together with the piston 3, the piston 3 performs a working fluid suction step in the compression chamber 11. When the drive shaft 2 moves in the other direction (arrow X2 direction) together with the piston 3, the piston 3 performs a working fluid compression process in the compression chamber 11. As described above, when power is supplied to the coil 4, the coil 4 is heated to generate Joule heat.

  When the piston 3 moves in the direction of the arrow X2 to perform the compression process of the compression chamber 11, the pressure in the first working chamber 12f becomes low and is reduced. Further, the coil 4 in the coil chamber 50 also moves together with the piston 3 and the drive shaft 2 toward the first through hole 51 in the direction of the arrow X2. For this reason, the fluid heated by the Joule heat of the coil 4 in the coil chamber 50 flows from the coil chamber 50 to the first working chamber 12f in the same direction (arrow X2 direction) through the first through hole 51. In this case, since the pressure in the first working chamber 12f is reduced as described above, the fluid in the second working chamber 12s flows in the same direction (arrow X2 direction) from the second working chamber 12s through the second through hole 52. ) Easily flows into the first working chamber 12f.

  On the other hand, when the piston 3 moves in the direction of the arrow X1 and performs the suction process of the compression chamber 11, the pressure in the first working chamber 12f increases and is increased. Furthermore, the coil 4 in the coil chamber 50 also moves away from the first through hole 51 in the direction of the arrow X1 together with the piston 3 and the drive shaft 2. For this reason, the fluid cooled in the first working chamber 12f passes through the first through hole 51 from the first working chamber 12f and flows into the coil chamber 50 in the same direction (arrow X1 direction). As described above, according to the present embodiment, the heat of the coil chamber 50 generated by the power supply to the coil 4 can move to the outside of the coil chamber 50 through the first through hole 51 of the permeable yoke 5. For this reason, overheating of the coil chamber 50 is suppressed, and overheating of the coil 4 disposed in the coil chamber 50 is suppressed. In this case, since the pressure in the first working chamber 12f is increased, the fluid cooled in the first working chamber 12f is in the same direction (arrow X1 direction) from the first working chamber 12f through the second through hole 52. It is thought that it flows into the 2nd working chamber 12s toward.

  According to the present embodiment, as in the first embodiment, the heat of the coil chamber 50 generated by the power feeding to the coil 4 passes through the first through hole 51 of the magnetically permeable yoke 5 and the coil chamber 50 is heated. Can move outward. For this reason, overheating of the coil chamber 50 is suppressed, and overheating of the coil 4 disposed in the coil chamber 50 is suppressed.

  Further, when the motor is driven, when the magnetic flux generated by the coil 4 passes through the magnetic permeable yoke 5 when the motor is driven, the current supplied to the coil 4 is an alternating current, so the direction of the magnetic flux is changed alternately. As a result, an eddy current is generated inside the permeable yoke 5 with the change of the magnetic flux. For this reason, depending on use conditions, there exists a possibility of raising the temperature of the magnetic permeability yoke 5 by the Joule heat by an eddy current. In this regard, according to the present embodiment, when the piston 3 moves in the directions of the arrows X1 and X2, the gaseous fluid passes through the second through hole 52 along with the pressure fluctuation in the first working chamber 12f. That is, since the fluid in the working chamber 12 moves between the first working chamber 12f and the second working chamber 12s via the second through hole 52 of the permeable yoke 5, the heat radiating property of the permeable yoke 5 is ensured. Is done. For this reason, overheating of the magnetically permeable yoke 5 is suppressed. In particular, the second through hole 52 is formed over the entire axial length of the outer yoke portion 55 of the permeable yoke 5, that is, from one end to the other end in the axial length direction of the permeable yoke 5. Good heat dissipation of the outer yoke portion 55 of the magnetic yoke 5 is ensured.

  FIG. 3 shows a third embodiment. The present embodiment basically has the same configuration and the same function and effect as the second embodiment. The first through hole 51 and the second through hole 52 have the same phase in the circumferential direction (arrow R direction) of the magnetically permeable yoke 5. Therefore, a good magnetic path is ensured in the permeable yoke 5. Further, the first through hole 51 and the second through hole 52 have an oval shape extending along the radial direction (arrow D direction) of the magnetically permeable yoke 5. In this case, the magnetic path generated in the permeable yoke 5 by the permanent magnet 6 is ensured satisfactorily. Therefore, the drive torque of the drive shaft 2 is maintained satisfactorily, and the compression stroke and suction process by the piston 3 are carried out satisfactorily. Further, in the permeable yoke 5, the eddy current loop flows so as to be orthogonal to the magnetic flux of the magnetic path MP. For this reason, when the first through hole 51 and the second through hole 52 are formed in an oval shape so as to extend along the radial direction (arrow D direction) of the magnetically permeable yoke 5, the eddy current loop is blocked. It is easy to ensure and can contribute to reducing eddy current loss.

  FIG. 4 shows a fourth embodiment. The present embodiment basically has the same configuration and the same function and effect as the second embodiment. The first through hole 51 and the second through hole 52 have the same phase in the circumferential direction (arrow R direction) of the magnetically permeable yoke 5. The first through hole 51 and the second through hole 52 are formed in a slit shape extending along the radial direction (arrow D direction) of the magnetically permeable yoke 5. In this case, it is suppressed that the magnetic path MD which generate | occur | produces in the magnetic permeability yoke 5 with the permanent magnet 6 is impaired, and the said magnetic path MD is ensured favorable. Therefore, the drive torque of the drive shaft 2 is maintained satisfactorily, and the compression stroke and suction process by the piston 3 are carried out satisfactorily. Furthermore, if the 1st through-hole 51 and the 2nd through-hole 52 are formed in slit shape, it can contribute also to reducing an eddy current loss.

  FIG. 5 shows a fifth embodiment. The present embodiment basically has the same configuration and the same function and effect as the second embodiment. As shown in FIG. 5, the magnetically permeable yoke 5 includes an inner yoke portion 54 disposed around the axis P1 of the drive shaft 2 and an inner yoke portion 54 disposed around the axis P1 of the drive shaft 2. An outer yoke portion 55 that is covered through the chamber 50, an intermediate yoke portion 56 that connects one end portion in the axial length direction of the outer yoke portion 55 and one end portion in the axial length direction of the inner yoke portion 54, an inner yoke portion 54, and an outer yoke portion And a coil chamber 50 formed by a yoke portion 55 and an intermediate yoke portion 56. In this case, as shown in FIG. 5, the through holes are formed in the intermediate yoke portion 56 and pass through the intermediate yoke portion 56, and the through holes are formed in the outer yoke portion 55 and pass through the outer yoke portion 55. 2 through-holes 52.

  FIG. 5 shows a cross section along the axis P <b> 1 of the drive shaft 2, that is, the axis of the permeable yoke 5. In the cross section shown in FIG. 5, the side close to the coil chamber 50 (the side far from the compression chamber 11) in the first through hole 51 is one end 51 e, and the side far from the coil chamber 50 in the first through hole 51 (compression chamber). 11) is the other end 51f. In this case, with regard to the flow path cross-sectional area of the first through hole 51, the one end 51e is larger than the other end 51f, and the other end 51f is smaller than the one end 51e.

  In other words, the flow passage cross-sectional area of the first through hole 51 is set to gradually decrease from the one end 51e to the other end 51f. Specifically, the first through hole 51 has a conical surface shape in which the flow path cross-sectional area gradually decreases from the coil chamber 50 toward the first working chamber 12f (compression chamber 11).

  In this embodiment, the fluid flow rate per unit time flowing out from the coil chamber 50 to the first working chamber 12f is Vout, and the fluid flow rate per unit time flowing into the coil chamber 50 from the first working chamber 12f is Vin. Then, Vin is more easily limited than Vout and becomes smaller (Vin <Vout). As a result, when the piston 3 reciprocates together with the drive shaft 2, in the working chamber 12, the coil chamber 50 → the first through hole 51 → the first working chamber 12f → the second through hole 52 → the second working chamber 12s → the coil chamber. The advantage that it is easy to form the circulation channel SA that circulates to 50 is obtained.

  According to such a present Example, since the heat generated in the coil chamber 50 can move from the first through hole 51 to the first working chamber 12f side, it is reduced. Further, the heat generated in the coil chamber 50 can move from the second through hole 52 to the outer yoke portion 55 of the permeable yoke 5 when flowing through the second through hole 52. As a result, it is expected that heat can be radiated to the housing 1 that contacts the outer wall surface 55s of the outer yoke portion 55 while facing it. It is advantageous for heat radiation of the coil chamber 50 if the heat dissipating fins 19 project from the outer wall surface of the housing 1 and a cooling medium (such as air) is brought into contact with the heat dissipating fins 19. Of course, the heat radiating fins 19 may not be projected from the housing 1 but may be naturally radiated from the housing 1.

  According to the present embodiment, the through-holes 51 and 52 may have a perfect circle shape in a cross section in a direction orthogonal to the axis P1 of the drive shaft 2, or as shown in FIGS. An elliptical shape extending along the radial direction (arrow D direction) of the magnetic yoke 5 or a slit shape extending along the radial direction of the magnetically permeable yoke 5 may be used.

  FIG. 6 shows a sixth embodiment. The present embodiment basically has the same configuration and the same function and effect as the fifth embodiment. As shown in FIG. 6, the through holes are formed in the intermediate yoke portion 56 and pass through the intermediate yoke portion 56, and the second through hole is formed in the outer yoke portion 55 and passes through the outer yoke portion 55. 52.

  FIG. 6 shows a cross section along the axis of the magnetically permeable yoke 5. As shown in FIG. 6, a check valve 70 is attached to the first through hole 51. The check valve 70 includes a valve 70a and a holding portion 70c that holds the valve 70a. The valve 70a is displaceable in a valve opening direction (V1 direction) for opening the first through hole 51 and a valve closing direction (V2 direction) for closing the first through hole 51. Such a check valve 70 can exhibit a valve opening function or a valve closing function with respect to the coil chamber 50 so as to form a flow path flow with respect to the coil chamber 50. In this case, as can be understood from FIG. 6, when the valve portion 70a is opened, fluid flow from the coil chamber 50 to the first working chamber 12f is allowed. On the other hand, when the valve portion 70a is closed, the fluid flow from the first working chamber 12f to the coil chamber 50 is blocked.

  In this embodiment, when the piston 3 reciprocates together with the drive shaft 2, the fluid flow rate flowing out from the coil chamber 50 to the first working chamber 12f is Vout, and the fluid flow rate flowing into the coil chamber 50 from the first working chamber 12f is Assuming Vin, Vin is limited by the check valve 70 (Vin <Vout). On the other hand, Vout is basically not limited by the check valve 70. As a result, when the piston 3 reciprocates in the directions of the arrows X1 and X2 together with the drive shaft 2, in the working chamber 12, the coil chamber 50 → first through hole 51 → first working chamber 12f → second through hole 52 → second. There is an advantage that it is easy to form the circulation channel SA that circulates from the working chamber 12 s to the coil chamber 50.

  According to the present embodiment, the heat generated in the coil chamber 50 can move from the first through hole 51 and the second through hole 522 to the outer yoke portion 55 of the magnetically permeable yoke 5. Heat can be dissipated to the housing 1 facing. Note that if the heat radiating fins 19 project from the housing 1 and a cooling medium (air or the like) is brought into contact with the heat radiating fins 19, it is advantageous for heat radiation of the coil chamber 50. Note that the heat radiation fins 19 may be naturally radiated from the housing 1 without protruding the heat radiation fins 19 from the housing 1.

  According to the present embodiment, the through holes 51 and 52 may have a perfect circle shape as shown in FIGS. 3 and 4 in a cross section in a direction perpendicular to the axis P1 of the drive shaft 2, or may be transparent. It may have an oval shape extending along the radial direction of the magnetic yoke 5 or a slit shape extending along the radial direction of the magnetically permeable yoke 5.

  FIG. 7 shows a seventh embodiment. The present embodiment basically has the same configuration and the same function and effect as the second embodiment. The magnetically permeable yoke 5 is composed of a plurality of plate-like members 58 formed of a material having high magnetic permeability (for example, pure iron, silicon steel, etc.) with the axis of the permeable yoke 5 (the axis P1 of the drive shaft 2) as the center. Are arranged in a radial pattern. The plate-like member 58 has high continuity in the radial direction (arrow D direction) of the permeable yoke 5. For this reason, the magnetic path in the permeable yoke 5 is ensured satisfactorily. However, in the magnetically permeable yoke 5, a plurality of gap layers 59 are alternately formed in the circumferential direction (arrow R direction). That is, a gap layer 59 is formed between adjacent plate-like members 58. The gap layer 59 extends along the axial length direction of the magnetically permeable yoke 5 and serves as a flow path that forms the second through hole 52.

  Here, since the eddy current resulting from the change of the magnetic flux forming the magnetic path is generated in a plane perpendicular to the magnetic flux forming the magnetic path, the eddy current is generated in the circumferential direction (arrow R direction) of the magnetically permeable yoke 5. It becomes easy to form a loop that flows along. In this respect, according to the present embodiment, as described above, a plurality of gap layers 59 are alternately formed in the circumferential direction (arrow R direction) of the magnetically permeable yoke 5, which contributes to reducing the eddy current loop. can do. Therefore, the advantage that the heat generation of the magnetic permeable yoke 5 due to the eddy current loop is suppressed is obtained, and the temperature rise of the magnetic permeable yoke 5 is suppressed.

  Further, as shown in FIG. 7, in the permeable yoke 5, since a large number of gap layers 59 are formed between the adjacent plate-like members 58, the exposed area of the permeable yoke 5 itself increases, and as a result, the heat dissipation area. Increases, and the contact area between the permeable yoke 5 and the fluid in the working chamber 12 increases. For this reason, it can contribute to improving the heat dissipation of the magnetically permeable yoke 5.

  Since this embodiment basically has the same configuration and the same function and effect as those of the second embodiment, FIG. 2 is applied mutatis mutandis. When the sum of the channel cross-sectional areas of the first through holes 51 is S1, and the sum of the channel cross-sectional areas of the second through holes 52 is S2, the relationship of S1> S2 is set. The flow rate of the fluid per unit time passing through the first through hole 51 increases. For this reason, it is possible to contribute to releasing the heat accumulated in the coil chamber 50 from the first through hole 51 toward the first working chamber 12f.

  Since this embodiment basically has the same configuration and the same function and effect as those of the second embodiment, FIG. 2 is applied mutatis mutandis. As shown in FIG. 2, when the sum of the cross-sectional areas of the first through holes 51 is S1, and the sum of the cross-sectional areas of the second through holes 52 is S2, the relationship of S1 <S2 is set. Yes. In this case, the flow rate of the fluid per unit time passing through the second through hole 52 increases. For this reason, it is possible to contribute to releasing heat based on eddy current generated in the outer yoke portion 55 of the magnetically permeable yoke 5 through the second through hole 52.

  FIG. 8 shows a tenth embodiment. The present embodiment basically has the same configuration and the same function and effect as the fifth embodiment. As shown in FIG. 8, the first through hole 51 is formed as a conical hole. Therefore, as described above, when the piston 3 reciprocates in the directions of the arrows X1 and X2 together with the drive shaft 2, in the working chamber 12, the coil chamber 50 → the first through hole 51 → the first working chamber 12f → the second penetration. A circulation passage SA through which a gaseous fluid circulates is formed in the hole 52 → the second working chamber 12s → the coil chamber 50, and heat is easily radiated from the outer wall 13 of the housing 1. For this reason, it can contribute to the heat radiation of the coil chamber 50 which tends to become high temperature, and the overheating of the coil 4 in the coil chamber 50 is suppressed.

  Further, as shown in FIG. 8, a cooling element 80 is provided in the second working chamber 12 s of the working chamber 12. Therefore, in the working chamber 12, when the gaseous fluid circulates in the coil chamber 50 → the first through hole 51 → the first working chamber 12 f → the second through hole 52 → the second working chamber 12 s → the coil chamber 50, Therefore, it is possible to positively exchange heat between the fluid immediately before entering the coil chamber 50, which tends to be heated due to the heat generation of 4, and the cooling element 80. Therefore, the gaseous fluid immediately before entering the coil chamber 50 can be positively cooled, which is effective for suppressing the temperature rise of the coil chamber 50.

  Here, as shown in FIG. 8, the one end 51e of the cooling element 80 is connected to a cooling water inlet (refrigerant inlet). The other end 51f of the cooling element 80 is connected to a cooling water outlet (refrigerant outlet). When cooling water (refrigerant) is supplied from the cooling water inlet to the cooling element 80, the cooling element 80 cools the fluid in the second working chamber 12 s and thus cools the fluid in the working chamber 12 of the housing 1. As a result, the coil chamber 50 and the permeable yoke 5 are cooled. Further, as shown in FIG. 8, the cooling element 80 faces the end 8 e of the drive shaft 2 while approaching. For this reason, the temperature rise of the drive shaft 2 is also suppressed, which is more advantageous for suppressing the temperature rise of the coil 4. In other embodiments, a cooling element 80 may be provided.

  FIG. 9 shows Example 11. The present embodiment basically has the same configuration and the same function and effect as the fifth embodiment. As shown in FIG. 9, the first through hole 51 is formed as a conical hole. Therefore, as described above, when the piston 3 reciprocates together with the drive shaft 2 in the directions of the arrows X1 and X2, in the working chamber 12, the coil chamber 50 → the first through hole 51 → the first working chamber 12f → the second through hole. 52 → second working chamber 12 s → coil chamber 50 can easily form a circulation channel through which a gaseous fluid circulates.

  As shown in FIG. 9, a first cooling element 80 </ b> F is provided in the first working chamber 12 f of the working chamber 12. One end 80e of the first cooling element 80F is connected to a cooling water inlet (refrigerant inlet). The other end 80f of the first cooling element 80F is connected to a cooling water outlet (refrigerant outlet). When cooling water (refrigerant) is supplied from the cooling water inlet to the first cooling element 80, the first cooling element 80F cools the fluid in the first working chamber 12f, and consequently the fluid in the working chamber 12 of the housing 1. As a result, the coil chamber 50 and the magnetically permeable yoke 5 are cooled.

  In particular, since the first bearing 21 has air permeability in the thickness direction (the direction of the arrow T1), the first bearing 21 passes through the first through hole 51 from the coil chamber 50 to the first working chamber 12f. The first fluid passes through the first bearing 21, reaches the vicinity of the first cooling element 80F, and is effectively cooled by the first cooling element 80F. Thus, the fluid immediately after passing through the first through hole 51 from the coil chamber 50 can be effectively cooled by the first cooling element 80F.

  As shown in FIG. 9, the first cooling element 80 </ b> F has an insertion hole 85 for inserting the drive shaft 2. For this reason, it is suppressed that the 1st cooling element 80F and the drive shaft 2 interfere. Further, the insertion hole 85 maintains the communication in the first working chamber 12f. Therefore, the pressure fluctuation in the first working chamber 12f accompanying the reciprocating movement of the piston 3 in the directions of the arrows X1 and X2 can affect the fluid permeability in the first through hole 51.

  As shown in FIG. 9, a second cooling element 80 </ b> S is provided in the second working chamber 12 s of the working chamber 12. One end 80e of the second cooling element 80S is connected to a cooling water inlet (refrigerant inlet). The other end 80f of the second cooling element 80S is connected to a cooling water outlet (refrigerant outlet). When cooling water (refrigerant) is supplied from the cooling water inlet to the second cooling element 80S, the second cooling element 80S cools the gaseous fluid in the second working chamber 12s, and thus in the working chamber 12 of the housing 1. The coil chamber 50 and the magnetically permeable yoke 5 are cooled.

  In particular, since the second bearing 22 has air permeability in the thickness direction (arrow T2 direction), the gaseous fluid cooled by the second cooling element 80S passes through the second bearing 22 and enters the coil chamber 50. As a result, the temperature rise of the coil chamber 50 can be suppressed. In other embodiments, the first cooling element 80F and the second cooling element 80S may be provided.

  FIG. 10 shows a twelfth embodiment. The present embodiment basically has the same configuration and the same function and effect as the fifth embodiment. FIG. 10 shows a cross section along the axis of the magnetically permeable yoke 5. The first through hole 51 is formed as a conical hole. In the working chamber 12, it is easy to form a circulation flow path that circulates through the coil chamber 50 → the first through hole 51 → the first working chamber 12 f → the second through hole 52 → the second working chamber 12 s → the coil chamber 50.

  According to the present embodiment, the heat generated in the coil chamber 50 can move from the second through hole 52 to the outer yoke portion 55 of the magnetically permeable yoke 5, and as a result, the housing that contacts and contacts the outer yoke portion 55. 1 is expected to be able to dissipate heat. As described above, if the heat dissipating fins project from the housing 1 and a cooling medium (air or the like) is brought into contact with the heat dissipating fins, it is advantageous for heat dissipation of the coil chamber 50. The housing 1 may be radiated naturally from the housing 1 without projecting the radiating fins. A cooling element 80 is provided in the second working chamber 12s of the working chamber 12, and the gaseous fluid on the coil chamber 50 side can be effectively cooled.

  The refrigeration cycle system 9 </ b> B that is an operating system includes a high pressure passage 91 that communicates with the compression chamber 11, a high pressure tank 92 that communicates with the high pressure passage 91, a low pressure passage 93 that communicates with the compression chamber 11, and a low pressure that communicates with the low pressure passage 93. The tank 94 includes a low-pressure tank 94 and a refrigerator 95 connected to the high-pressure tank 92. A high pressure check valve 96 is provided in the high pressure passage 91. The high pressure check valve 96 allows the working fluid to flow from the compression chamber 11 to the high pressure tank 92, but prevents the working fluid from flowing from the high pressure tank 92 to the compression chamber 11. A low pressure check valve 97 is provided in the low pressure passage 93. The low pressure check valve 97 prevents the working fluid from flowing from the compression chamber 11 to the low pressure tank 94, but allows the working fluid to flow from the low pressure tank 94 to the compression chamber 11.

  FIG. 11 shows a thirteenth embodiment. This embodiment basically has the same configuration and the same function and effect as the third embodiment. As shown in FIG. 11, the blades 23 x functioning as a blower are attached so as to face the opening of the second through hole 52. When the drive shaft 2 reciprocates along the directions of the arrows X1 and X2, the blades 23x operate in the same direction to positively move the fluid in the second through hole 52, and the outer yoke portion 55 of the permeable yoke 5. It can be expected to improve the heat dissipation. The blades 23x are provided on the attachment portion 23w of the attachment 23, but may be provided directly on the drive shaft 2. Similarly, other embodiments may be provided with blades 23x.

  FIG. 12 shows Example 14. This embodiment basically has the same configuration and the same function and effect as the third embodiment. FIG. 12 shows a cross section along the axis of the magnetically permeable yoke 5. The flow passage cross-sectional area of the first through hole 51 is set so as to gradually decrease from the one end 51e to the other end 51f. For this reason, as described above, in the working chamber 12, the circulation flow path that circulates in the coil chamber 50 → the first through hole 51 → the first working chamber 12 f → the second through hole 52 → the second working chamber 12 s → the coil chamber 50. Is easy to form. According to the present embodiment, the heat generated in the coil chamber 50 can move from the first through hole 51 to the outer yoke portion 55 of the magnetically permeable yoke 5, and as a result, the housing that contacts and contacts the outer yoke portion 55. 1 is expected to dissipate heat. If a heat radiating fin is protruded from the housing 1 and a cooling medium (air or the like) is brought into contact with the heat radiating fin, it is advantageous for heat radiation of the coil chamber 50. The housing 1 may be radiated naturally from the housing 1 without projecting the radiating fins. A cooling element 80 that cools the fluid in the working chamber 12 is provided in the second working chamber 12 s of the working chamber 12.

  As shown in FIG. 12, the refrigeration cycle system 9C is a pulse tube refrigeration system, and includes a heat exchanger chamber 101 for heat dissipation, a regenerator 102, a pulse tube 104 having a hollow chamber 103, and a pulse tube 104. A high temperature side heat exchanger 105 provided on the high temperature end side, a low temperature side heat exchanger 106 provided on the low temperature end side of the pulse tube 104, and a buffer tank 107 communicating with the low temperature side heat exchanger 106 Have.

(Other)
In the above-described embodiment, the permanent magnet 6 is fixed and the coil 4 is moved in the coil chamber 50. However, the present invention is not limited to this, and a method in which the permanent magnet 6 is moved and the coil 4 is fixed may be used. . The refrigeration cycle system described above can be used for various refrigeration systems such as a pulse tube refrigerator, a GM refrigerator, a Stirling refrigerator, and a thermoacoustic refrigerator. The motor can also be applied to uses other than the refrigeration cycle.

  In the embodiment shown in FIG. 5, the first through hole 51 has a conical surface shape in which the flow path cross-sectional area gradually decreases from the coil chamber 50 toward the first working chamber 12f, but is not limited to the conical hole. In short, when the side close to the coil chamber 50 in the first through hole 51 is the one end 51e and the side far from the coil chamber 50 in the first through hole 51 is the other end 51f, The channel cross-sectional area may be larger at the one end 51e than at the other end 51f and smaller at the other end 51f than at the one end 51e. In some cases, the first through hole 51 may be a straight hole having the same inner diameter over the long direction. The air blowing part may be provided in the first through hole 51. The present invention is not limited to the embodiments and examples described above, and can be implemented with appropriate modifications within a range not departing from the gist. Structures and functions specific to one embodiment can be applied to other embodiments.

  In the figure, 1 is a housing, 11 is a compression chamber, 12 is a working chamber, 13 is an outer wall, 14 is an end wall, 2 is a drive shaft, 21 and 22 are bearings, 23x is a blade (blower), 3 is a piston, 4 Is a coil, 5 is a magnetically permeable yoke, 50 is a coil chamber, 54 is an inner yoke portion, 55 is an outer yoke portion, 56 is an intermediate yoke portion, 51 is a first through hole, 52 is a second through hole, and 58 is a plate shape Members, 6 is a permanent magnet, 70 is a check valve, 80 is a cooling element, 9 is a refrigeration cycle system, and 95 is a refrigerator.

Claims (4)

A housing with a working chamber;
A drive shaft provided in the working chamber of the housing so as to be capable of reciprocating in the longitudinal direction;
A movable body provided on the drive shaft and reciprocating with the reciprocation of the drive shaft;
A permanent magnet provided in the working chamber of the housing;
A coil that is provided so as to move relative to the permanent magnet and is arranged in the working chamber of the housing and is fed with power;
A magnetic path for reciprocating the drive shaft, and a magnetic permeability yoke formed of a magnetic permeability material formed by a magnetic field generated by the coil and the permanent magnet,
The permeable yoke is
A coil chamber in which the coil is disposed; and a through hole that allows the inside of the coil chamber to communicate with the outside of the coil chamber; and the fluid inside the coil chamber passes through the through hole to A reciprocating motor which is discharged outward and has the following configuration (1), (2) and / or (3).
(1) In the cross section along the axial center of the magnetically permeable yoke, when the through hole has a side closer to the coil chamber as one end and the side of the through hole far from the coil chamber has the other end. The flow passage cross-sectional area of the through hole is larger at the one end than at the other end and smaller at the other end than the one end.
(2) A check valve that allows a one-way flow of fluid in the through hole and prevents a reverse flow is provided in the through hole.
(3) The magnetically permeable yoke includes an inner yoke portion disposed around the shaft core of the drive shaft, and the inner yoke portion disposed around the shaft core of the drive shaft via the coil chamber. An outer yoke portion that covers the intermediate yoke portion that connects an end portion in the axial length direction of the outer yoke portion and an end portion in the axial length direction of the inner yoke portion, the inner yoke portion, the outer yoke portion, and the intermediate yoke And the through hole is formed in the intermediate yoke portion and penetrates the intermediate yoke portion, and communicates the inside of the coil chamber with the outside of the coil chamber. A first through hole; and a second through hole formed in the outer yoke portion and penetrating the outer yoke portion.   2. The magnetically permeable yoke according to claim 1, wherein the magnetically permeable yoke includes an inner yoke portion disposed around the axis of the drive shaft, and the inner yoke portion disposed around the axis of the drive shaft via the coil chamber. An outer yoke portion that covers the intermediate yoke portion that connects an end portion in the axial length direction of the outer yoke portion and an end portion in the axial length direction of the inner yoke portion, the inner yoke portion, the outer yoke portion, and the intermediate yoke A reciprocating movement, wherein the through hole is formed in the intermediate yoke portion so as to penetrate the intermediate yoke portion and to face the coil chamber. Motor. 3. The reciprocating motor according to claim 1 , wherein a cooling element that cools the fluid by exchanging heat with the fluid in the working chamber is provided in the working chamber. The air blowing part which raises the fluid passage amount in the said through-hole by blowing a fluid to the said through-hole with reciprocating movement of the said drive shaft in one of Claims 1-3 is provided. A reciprocating motor.

Images