Magnetic refrigeration unit and refrigeration device

Abstract

To apply an appropriate magnetic field to a magnetic work substance with a necessary minimum amount of magnets.SOLUTION: Two first rotating bodies (21) are disposed with an interval in an axial direction of a rotating shaft (16). A second rotating body (22) is disposed between the two first rotating bodies (21). A first magnetic work substance (13) is arranged between the first rotating body (21) and the second rotating body (22). The first rotating body (21) is provided with a first magnet (31). The second rotating body (22) is provided with a second magnet (32). Magnetomotive force F1 of the first magnet (31) and magnetomotive force F2 of the second magnet (32) satisfy a following condition, F1<F2<2×F1.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a magnetic refrigeration unit and a refrigeration device. [Background technology]

[0002] Patent document 1 discloses a rotating magnetic field generating device that includes a disk with multiple magnets arranged circumferentially, a magnetic working material arranged in a magnetic field action space formed by stacking the disks at intervals so that the multiple magnets face each other, and a drive mechanism that rotates a rotating axis (shaft) to which the disk is fixed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 190586 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when three or more magnets are arranged in the axial direction of the rotation shaft and a magnetic field is applied to a magnetic working material arranged between the magnets, if magnets with the same magnetomotive force are used, the amount of magnets will be excessive compared to the applied magnetic field strength required by the magnetic working material, resulting in an increase in costs.

[0005] An object of the present disclosure is to make it possible to apply an appropriate magnetic field to a magnetic working material using the minimum necessary amount of magnets. [Means for solving the problem]

[0006] A first aspect of the present disclosure includes a rotation axis (16), two first rotors (21) arranged at an axial interval along the rotation axis (16) and rotating together with the rotation axis (16), a second rotor (22) arranged between the two first rotors (21) and rotating together with the rotation axis (16), a first magnetic working substance (13) arranged between the first rotor (21) and the second rotor (22), a first magnet (31) provided on the first rotor (21) and applying a magnetic field to the first magnetic working substance (13 in the axial direction opposite to the rotation axis (16), and a second magnet (32) provided on the second rotor (22) and applying a magnetic field to the first magnetic working substance (13) in the axial direction opposite to the rotation axis (16). The magnetic refrigeration unit satisfies the condition that the magnetomotive force F1 of the first magnet (31) and the magnetomotive force F2 of the second magnet (32) satisfy F1 < F2 < 2×F1.

[0007] In the first aspect, by appropriately setting the magnetomotive force of the first magnet (31) and the magnetomotive force of the second magnet (32), an appropriate magnetic field can be applied to the first magnetic working substance (13) with a minimum required amount of magnets, and the costs of the first magnet (31) and the second magnet (32) can be reduced.

[0008] A second aspect of the present disclosure is the magnetic refrigeration unit according to the first aspect, wherein two or more second rotors (22) are provided at an axial interval along the rotation axis (16), and a second magnetic working substance (14) arranged between the two second rotors (22) is provided.

[0009] In the second aspect, by providing a plurality of second rotors (22), a magnetic field can be applied to the second magnetic working substance (14).

[0010] A third aspect of the present disclosure is the magnetic refrigeration unit according to the first or second aspect, wherein the first magnet (31) and the second magnet (32) are made of a material with the same coercive force, and the thickness t1 of the first magnet (31) and the thickness t2 of the second magnet (32) satisfy the condition t1 < t2 < 2×t1.

[0011] In the third aspect, the magnetomotive forces of the first magnet (31) and the second magnet (32) can be changed by appropriately setting the thickness of the first magnet (31) and the thickness of the second magnet (32).

[0012] A fourth aspect of the present disclosure is a magnetic refrigeration unit according to the first or second aspect, wherein the first magnet (31) and the second magnet (32) are composed of electromagnets (50) that generate magnetomotive force when current is passed through a winding (40), and the first magnet (31) and the second magnet (32) differ in at least one of the number of turns of the winding (40) and the value of the current passed therethrough.

[0013] In the fourth aspect, the magnetomotive forces of the first magnet (31) and the second magnet (32) can be changed by appropriately setting at least one of the number of turns of the windings (40) of the first magnet (31) and the second magnet (32) and the value of the current flowing therethrough.

[0014] A fifth aspect of the present disclosure is a refrigeration system including the magnetic refrigeration unit (10) according to any one of the first to fourth aspects, and a heat medium circuit (2) exchanging heat with the magnetic refrigeration unit (10).

[0015] In a fifth aspect, a refrigeration system can be provided, which includes a magnetic refrigeration unit (10) and a heat medium circuit (2). [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a piping diagram of a refrigeration system according to the first embodiment. [Figure 2] FIG. 2 is a diagram showing the configuration of the magnetic refrigeration unit. [Figure 3] FIG. 3 is a diagram showing the arrangement of magnets in Comparative Example 1. As shown in FIG. [Figure 4] FIG. 4 is a diagram showing a magnetoresistive circuit. [Figure 5] FIG. 5 is a diagram showing the arrangement of magnets in Comparative Example 2. As shown in FIG. [Figure 6] FIG. 6 is a diagram showing a magnetoresistive circuit. [Figure 7]FIG. 7 is a diagram showing the arrangement of magnets in the first embodiment. [Figure 8] FIG. 8 is a diagram showing a magnetoresistive circuit. [Figure 9] FIG. 9 is a diagram showing the flow of magnetic flux in a modified example of the first embodiment. [Figure 10] FIG. 10 is a diagram showing the configuration of a magnetic refrigeration unit according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] First Embodiment As shown in Fig. 1, a refrigeration system (1) includes a heat medium circuit (2). The refrigeration system (1) is applied to, for example, an air conditioner. The heat medium circuit (2) is filled with a heat medium. The heat medium includes, for example, a refrigerant, water, brine, etc.

[0018] The refrigeration system (1) includes a low-temperature side heat exchanger (3), a high-temperature side heat exchanger (4), a pump (5), and a magnetic refrigeration unit (10). The magnetic refrigeration unit (10) adjusts the temperature of a heat medium by utilizing the magnetocaloric effect.

[0019] The heat medium circuit (2) is formed in a closed loop, and includes a pump (5), a low-temperature side heat exchanger (3), a magnetic refrigeration unit (10), and a high-temperature side heat exchanger (4) connected in this order.

[0020] The heat medium circuit (2) includes a low-temperature side flow path (2a) and a high-temperature side flow path (2b). The low-temperature side flow path (2a) connects a temperature control flow path (10a) of the magnetic refrigeration unit (10) to a first port (6a) of the pump (5). The high-temperature side flow path (2b) connects the temperature control flow path (10a) of the magnetic refrigeration unit (10) to a second port (6b) of the pump (5).

[0021] <Low temperature heat exchanger and high temperature heat exchanger> The low-temperature side heat exchanger (3) exchanges heat between the heat medium cooled by the magnetic refrigeration unit (10) and a predetermined object to be cooled (e.g., a secondary refrigerant or air). The high-temperature side heat exchanger (4) exchanges heat between the heat medium heated by the magnetic refrigeration unit (10) and a predetermined object to be heated (e.g., a secondary refrigerant or air).

[0022] <pump> The pump (5) alternately performs a first operation and a second operation. In the first operation, the heat medium in the heat medium circuit (2) is transported leftward in FIG. 1. In the second operation, the heat medium in the heat medium circuit (2) is transported rightward in FIG. 1. The pump (5) constitutes a transport mechanism that causes the heat medium in the heat medium circuit (2) to flow reciprocally.

[0023] The pump (5) is a reciprocating piston pump and includes a pump case (6) and a piston (7).

[0024] The piston (7) is arranged inside the pump case (6) so as to be able to move back and forth. The piston (7) divides the interior of the pump case (6) into a first chamber (S1) and a second chamber (S2). The pump case (6) is formed with a first port (6a) and a second port (6b). The first port (6a) communicates with the first chamber (S1). The first port (6a) is connected to the low-temperature side flow path (2a). The second port (6b) communicates with the second chamber (S2). The second port (6b) is connected to the high-temperature side flow path (2b). The piston (7) is driven by a drive mechanism (not shown).

[0025] In the first operation, the piston (7) moves toward the first port (6a). In the first operation, the volume of the first chamber (S1) decreases and the volume of the second chamber (S2) increases. As a result, the heat transfer medium in the first chamber (S1) is discharged into the low-temperature side flow path (2a) through the first port (6a). At the same time, the heat transfer medium in the high-temperature side flow path (2b) is sucked into the second chamber (S2) through the second port (6b).

[0026] In the second action, the piston (7) moves toward the second port (6b). In the second action, the volume of the second chamber (S2) decreases and the volume of the first chamber (S1) increases. As a result, the heat transfer medium in the second chamber (S2) is discharged into the high-temperature side flow path (2b) through the second port (6b). At the same time, the heat transfer medium in the low-temperature side flow path (2a) is sucked into the first chamber (S1) through the first port (6a).

[0027] <Control Unit> The refrigeration system 1 includes a control unit 8. The control unit 8 controls the operations of the pump 5 and the magnetic refrigeration unit 10 in response to a predetermined operation command. The control unit 8 includes a microcomputer and a memory device (specifically, a semiconductor memory) that stores software for operating the microcomputer.

[0028] <Magnetic Refrigeration Unit> As shown in FIG. 2, the magnetic refrigeration unit (10) includes a magnetic working material (11), a magnetic field application unit (12), and a rotation mechanism (15).

[0029] The magnetic working material (11) generates heat when a magnetic field is applied. The magnetic working material (11) absorbs heat when the magnetic field is removed. The magnetic working material (11) also generates heat when the applied magnetic field becomes stronger. The magnetic working material (11) also absorbs heat when the applied magnetic field becomes weaker. A plurality of magnetic working materials (11) are arranged at intervals around the circumferential direction of the rotating shaft (16).

[0030] A pipe (35) is connected to the magnetic working material (11). The pipe (35) constitutes a low-temperature side flow path (2a) and a high-temperature side flow path (2b) of the heat medium circuit (2) (see FIG. 1). A heat exchange medium that exchanges heat with the magnetic working material (11) flows through the pipe (35). The pipe (35) is connected to the magnetic working material (11) at a radially outer side of the rotating shaft (16).

[0031] The material of the magnetic working material (11) is, for example, Gd5 (Ge 0.5 Si 0.5 )4, La(Fe 1-xSi x ) 13 , La(Fe 1-x Co x Si y ) 13 , La(Fe 1-x Si x ) 13 H y , Mn(As 0.9 Sb 0.1 ) etc. can be used.

[0032] The rotation mechanism (15) has a rotation shaft (16) and a motor (17). The rotation shaft (16) is connected to the motor (17). The motor (17) rotates the rotation shaft (16). The magnetic field application unit (12) is connected to the rotation shaft (16).

[0033] The magnetic field application unit (12) has a first rotating body (21) and a second rotating body (22). Two first rotating bodies (21) are arranged at an interval in the axial direction of the rotating shaft (16). The first rotating bodies (21) rotate around the axis of the rotating shaft (16) in conjunction with the rotation of the motor (17).

[0034] The second rotor (22) is disposed between the two first rotors (21). Two or more second rotors (22) are provided at intervals in the axial direction of the rotary shaft (16). In the example shown in FIG. 2, two second rotors (22) are provided. The second rotors (22) rotate around the axis of the rotary shaft (16) in conjunction with the rotation of the motor (17).

[0035] The magnetic working material (11) includes a first magnetic working material (13) and a second magnetic working material (14). The first magnetic working material (13) is disposed between a first rotating body (21) and a second rotating body (22). The second magnetic working material (14) is disposed between two second rotating bodies (22).

[0036] The first magnetic working material (13) and the second magnetic working material (14) are made of the same material and have the same shape, but differ only in their arrangement relative to the first rotor (21) and the second rotor (22).

[0037] The first rotor (21) has a first core (25) and a plurality of first magnets (31). The first core (25) is made of a magnetic material. The first core (25) is fixed to the rotary shaft (16).

[0038] The plurality of first magnets (31) are provided on a surface of the first core portion (25) facing the first magnetic working material (13). The plurality of first magnets (31) are arranged at intervals in the circumferential direction of the rotating shaft (16). The first magnets (31) are made of permanent magnets. The magnetization direction of the first magnets (31) is oriented in the axial direction of the rotating shaft (16). The first magnets (31) constitute the magnetic poles of the first rotating body (21).

[0039] The second rotor (22) has a support portion (26) and a plurality of second magnets (32). The support portion (26) is made of a non-magnetic material. The support portion (26) is fixed to the rotary shaft (16).

[0040] The plurality of second magnets (32) are arranged radially outward from the support portion (26). The second magnets (32) are arranged at intervals in the circumferential direction so as to face the first magnets (31). The second magnets (32) are arranged so as to face the second magnets (32) of the adjacent second rotating body (22). The second magnets (32) are made of permanent magnets. The magnetization direction of the second magnets (32) is oriented in the axial direction of the rotation shaft (16). The second magnets (32) constitute the magnetic poles of the second rotating body (22).

[0041] The first magnet (31) and the second magnet (32) may be made of a material such as an Nd-Fe-B based magnet or an SmCo based magnet.

[0042] Here, the axial distance between the first rotating body (21) and the second rotating body (22), i.e., the distance from the lower surface of the first magnet (31) of the first rotating body (21) to the upper surface of the second magnet (32) of the second rotating body (22) in Figure 2, is approximately equal to the distance between adjacent second rotating bodies (22), i.e., the distance from the lower surface of the second magnet (32) of the upper second rotating body (22) to the upper surface of the second magnet (32) of the lower second rotating body (22) in Figure 2.

[0043] The first rotating body (21) and the second rotating body (22) rotate relative to the first magnetic working material (13) and the second magnetic working material (14) in the circumferential direction, thereby applying a magnetic field toward the magnetic working material (11) facing the first magnet (31) of the first rotating body (21) and the second magnet (32) of the second rotating body (22).

[0044] In the first rotor (21) on the upper side in Fig. 2, magnetic flux flows from the first magnet (31) on the right side in Fig. 2 through the first core portion (25) toward the first magnet (31) on the left side in Fig. 2. The flow of magnetic flux is indicated by dashed arrows.

[0045] In the first rotor (21) on the lower side in FIG. 2, magnetic flux flows from the first magnet (31) on the left side in FIG. 2 through the first core portion (25) toward the first magnet (31) on the right side.

[0046] In the two second rotating bodies (22), magnetic flux flows in the axial direction in the following order: from the first magnet (31) of the first rotating body (21) to the second magnet (32), to the second magnet (32) of the adjacent second rotating body (22), and finally to the first magnet (31) of the first rotating body (21).

[0047] A magnetic flux flows in the axial direction through the magnetic working material 11 disposed between the first magnet 31 of the first rotating body 21 and the second magnet 32 ​​of the second rotating body 22. This causes the magnetic working material 11 to generate heat when the magnetic field is applied.

[0048] Thereafter, the first rotor (21) and the second rotor (22) are rotated so that the first magnet (31) of the first rotor (21) and the second magnet (32) of the second rotor (22) face the axial direction of the adjacent magnetic working material (11). As a result, the magnetic working material (11) to which the magnetic field was first applied absorbs heat when the magnetic field is removed. On the other hand, the adjacent magnetic working material (11) generates heat when the magnetic field is applied.

[0049] <About the magnetomotive force of magnets> By the way, when three or more magnets are arranged in the axial direction of the rotating shaft (16) and a magnetic field is applied to the magnetic working substance (11) arranged between the magnets, if magnets with the same magnetomotive force are used, there is a problem that the amount of magnets becomes excessive and the cost increases with respect to the applied magnetic field strength required by the magnetic working substance (11).

[0050] Therefore, in the present embodiment, it is possible to apply an appropriate magnetic field to the magnetic working substance (11) with the minimum necessary amount of magnets.

[0051] Specifically, the first magnet (31) and the second magnet (32) are made of a material with the same coercive force. The first magnet (31) and the second magnet (32) are set so that the thickness t1 of the first magnet (31) and the thickness t2 of the second magnet (32) satisfy the condition of t1 < t2 < 2×t1.

[0052] Thereby, the magnetomotive force F_1 of the first magnet (31) and the magnetomotive force F_2 of the second magnet (32) can be set to satisfy the condition of F_1 < F_2 < 2×F_1.

[0053] Hereinafter, as shown in Comparative Example 1 of FIG. 3, the case where only one layer of the magnetic working substance (11) is arranged between two first rotors (21) will be considered. In FIG. 3, for the sake of clarity of the drawing, the description of the rotating shaft (16) is omitted. <00,00221><, As shown in FIG. 3, let the thickness of the first magnet (31) be t1. As shown in FIG. 4, let the magnetomotive force of the first magnet (31) be F_1, the magnetic resistance of the magnetic working substance (11) be Ra, and the magnetic resistance of the first core portion (25) be Rc.

[0055] If the total magnetic resistance in the magnetic resistance circuit of FIG. 4 is R1, then R1 = 2×Ra + 2×Rc. If the total magnetomotive force in the magnetic resistance circuit of FIG. 4 is Fm, then Fm = 4×F_1. If the magnetic flux flowing through the magnetic resistance circuit is φ_1, then φ_1 = Fm / R1.

[0056] Next, in Comparative Example 2 shown in Fig. 5, a case will be considered in which magnetic working materials (11) are arranged in two tiers, one above the other, between two first rotating bodies (21). In Fig. 5, for ease of understanding, the rotating shaft (16) and the support portion (26) of the second rotating body (22) are omitted.

[0057] As shown in Fig. 5, second magnets (32) are arranged between the upper and lower two tiers of magnetic working materials (11). The second magnets (32) include a second magnet (32) corresponding to the upper first magnet (31) in Fig. 5 and a second magnet (32) corresponding to the lower first magnet (31) in Fig. 5. In other words, upper and lower two tiers of second magnets (32) are arranged between the upper and lower two tiers of magnetic working materials (11). Here, the thickness t1 of the second magnets (32) is set equal to the thickness t1 of the first magnets (31).

[0058] In the example shown in Fig. 6, a second magnet (32) surrounded by a dashed line in Fig. 6 is added to the magnetic resistance circuit of Comparative Example 1. The magnetomotive force of the second magnet (32) is the same as that of the first magnet (31), that is, magnetomotive force F1.

[0059] Next, as shown in Fig. 7, in this embodiment, only one stage of second magnets (32) is disposed between two stages of upper and lower magnetic working materials (11). As shown in Fig. 7, the thickness of the second magnets (32) is denoted by t2. As shown in Fig. 8, the magnetomotive force of the second magnets (32) is denoted by F2.

[0060] If the total magnetic resistance in the magnetic resistance circuit of FIG. 8 is R2, then R2=4×Ra+2×Rc. Here, if the total magnetic resistance added to the magnetic resistance circuit of Comparative Example 1 is R'2, then R'2=R2-R1=2×Ra. R'2 is smaller than R1 (R'2 <R1)。

[0061] Furthermore, if the magnetomotive force added to the magnetic resistance circuit of Comparative Example 1 is F'm, then F'm = 2 × F2. If the magnetic flux flowing through the magnetic resistance circuit is φ2, then φ2 = F'm / R'2.

[0062] Here, in the magnetoresistance circuit of Comparative Example 1 in FIG. 4 and the magnetoresistance circuit of FIG. 8, in order to make the magnetic flux amount constant, it is necessary to satisfy φ1 = φ2, and Fm / R1 = F’m / R’2. As a result, F’m = (R’2 / R1) × Fm.

[0063] Here, since Fm = 4 × F1 and F’m = 2 × F2, F2 = 2 × (R’2 / R1) × F1. Since R’2 < R1, (R’2 / R1) < 1.

[0064] From the above, considering the additional magnetoresistance in the magnetoresistance circuit of FIG. 8, the magnetomotive force of the magnet required to generate magnetic flux can be calculated. Specifically, the magnetomotive force per piece of the additional magnet in the magnetoresistance circuit of FIG. 8 is set so as to satisfy the condition F1 < F2 < 2 × F1.

[0065] Here, if the coercive force of the magnet is Hcj and the thickness of the magnet is t, the magnetomotive force is determined by Hcj × t. Therefore, when using magnets with the same coercive force, the thickness of the magnet may be set so as to satisfy the condition t1 < t2 < 2 × t1.

[0066] -Effect of Embodiment 1- According to the features of the present embodiment, by appropriately setting the magnetomotive force of the first magnet (31) and the magnetomotive force of the second magnet (32), an appropriate magnetic field can be applied to the first magnetic working substance (13) with the minimum necessary amount of magnets, and the costs of the first magnet (31) and the second magnet (32) can be reduced.

[0067] According to the features of the present embodiment, by providing a plurality of second rotors (22), a magnetic field can be applied to the second magnetic working substance (14).

[0068] According to the features of the present embodiment, by appropriately setting the thickness of the first magnet (31) and the thickness of the second magnet (32), the magnetomotive forces of the first magnet (31) and the second magnet (32) can be changed.

[0069] According to the features of the present embodiment, it is possible to provide a refrigeration system including a magnetic refrigeration unit (10) and a heat medium circuit (2).

[0070] <<Modification of the First Embodiment>> In the first embodiment, the magnetic flux flowing through the first magnet (31), magnetic working material (11), and second magnet (32) on the right side in FIG. 2 is made to flow through the first core portion (25) to the first magnet (31), magnetic working material (11), and second magnet (32) on the left side in FIG. 2, but this is not limited to this embodiment.

[0071] For example, by constructing the entire support portion (26) or a part thereof from a magnetic material and magnetically connecting the two upper and lower first core portions (25) to form a magnetic path, as shown in FIG. 9, the magnetic flux flowing through the first magnet (31), magnetic working material (11), and second magnet (32) on the right side in FIG. 9 may flow in the axial direction of the rotation shaft (16) via the first core portion (25), and then flow again through the first magnet (31), magnetic working material (11), and second magnet (32) on the right side in FIG. 9.

[0072] Similarly, the magnetic flux flowing through the first magnet (31), magnetic working material (11), and second magnet (32) on the left side in Figure 9 may be made to flow in the axial direction of the rotation shaft (16) via the first core portion (25), and then flow again through the first magnet (31), magnetic working material (11), and second magnet (32) on the left side in Figure 9.

[0073] Second Embodiment Hereinafter, the same parts as those in the first embodiment will be denoted by the same reference numerals, and only the differences will be described.

[0074] 10, the magnetic field applying unit (12) has a first rotating body (21) and a second rotating body (22). Two first rotating bodies (21) are arranged at an interval in the axial direction of the rotation shaft (16).

[0075] The second rotor (22) is disposed between two first rotors (21). Two or more second rotors (22) are provided at intervals in the axial direction of the rotation shaft (16). In the example shown in Fig. 10, two second rotors (22) are provided.

[0076] The magnetic working material (11) includes a first magnetic working material (13) and a second magnetic working material (14). The first magnetic working material (13) is disposed between a first rotating body (21) and a second rotating body (22). The second magnetic working material (14) is disposed between two second rotating bodies (22).

[0077] The first rotating body (21) has a first core portion (25) and a plurality of first magnets (31). The first magnets (31) are formed of electromagnets (50). Specifically, the first core portion (25) is formed of a magnetic material. A portion of the first core portion (25) protrudes toward the first magnetic working material (13). A winding (40) is wound around the protruding portion of the first core portion (25). The electromagnets (50) generate a magnetomotive force when current is applied to the winding (40).

[0078] The second rotor (22) has a support portion (26), a second core portion (27), and a plurality of second magnets (32). The support portion (26) is made of a non-magnetic material. The second core portion (27) is disposed radially outward of the support portion (26).

[0079] The second magnet (32) is formed of an electromagnet (50). The second core portion (27) is formed of a magnetic material. A winding (40) is wound around a part of the second core portion (27). The electromagnet (50) generates a magnetomotive force when a current is applied to the winding (40).

[0080] An electric wire 42 is connected to the winding 40. The electric wire 42 is routed along the rotating shaft 16. For example, the inside of the rotating shaft 16 may be hollow, and the electric wire 42 may be routed in the hollow portion of the rotating shaft 16.

[0081] A slip ring (45) is provided at the end of the rotating shaft (16) on the side opposite to the motor (17). The slip ring (45) has a ring portion (46) and a brush portion (47). The ring portion (46) is arranged concentrically with the rotating shaft (16) at the end of the rotating shaft (16). An electric wire (42) is connected to the ring portion (46).

[0082] The brush portion (47) is electrically connected to the ring portion (46). The brush portion (47) is connected to the power supply (41). The brush portion (47) is in contact with the ring portion (46) during the rotation of the rotating shaft (16). Thus, the current supplied from the power supply (41) flows through the brush portion (47), the ring portion (46), the electric wire (42) and toward the winding (40). When the winding (40) is energized, a magnetomotive force is generated in the electromagnet (50).

[0083] In the present embodiment, at least one of the number of turns of the winding (40) and the value of the current passed through the winding (40) is made different between the first magnet (31) and the second magnet (32). Specifically, when the number of turns of the electric wire (42) is N and the value of the current passed through is I, the magnetomotive force of the electromagnet (50) is determined by N×I. Here, let the number of turns of the winding (40) of the first magnet (31) be N1, and the number of turns of the winding (40) of the second magnet (32) be N2.

[0084] In the example shown in FIG. 10, the number of turns N2 of the winding (40) of the second magnet (32) is larger than the number of turns N1 of the winding (40) of the first magnet (31) (N2 > N1). Therefore, the magnetomotive force of the second magnet (32) becomes larger than the magnetomotive force of the first magnet (31).

[0085] Here, when the value of the current passed through the winding (40) is constant, by setting the number of turns of the winding (40) to satisfy the condition N1 < N2 < 2×N1, the magnetomotive force F1 of the first magnet (31) and the magnetomotive force F2 of the second magnet (32) can be set to satisfy the condition F1 < F2 < 2×F1.

[0086] Note that the number of turns of the winding (40) may be made the same, and the current value supplied to the second magnet (32) may be made larger than the current value supplied to the first magnet (31).

[0087] -Effects of Embodiment 2- According to the features of the present embodiment, by appropriately setting at least one of the number of turns of the windings (40) of the first magnet (31) and the second magnet (32) and the current value supplied, the magnetomotive force of the first magnet (31) and the second magnet (32) can be changed.

[0088] 《Other Embodiments》 The above embodiment may have the following configuration.

[0089] In the present embodiment, the first magnet (31) and the second magnet (32) have been described in a form composed of materials with the same coercive force, but the present invention is not limited to this form.

[0090] Specifically, since the magnetomotive force of a magnet is determined by Hcj×t, when magnets with different holding forces are used, the design conditions for the thickness of the magnets are not necessarily limited to t1 < t2 < 2×t1. In this case, the magnetomotive force F1 of the first magnet (31) and the magnetomotive force F2 of the second magnet (32) may be designed to satisfy the condition F1 < F2 < 2×F1.

[0091] In the present embodiment, the configuration in which the first magnet (31) and the second magnet (32) are each formed of a single magnet has been described, but the present invention is not limited to this form. For example, the first magnet (31) and the second magnet (32) may be formed by stacking a plurality of magnets. Here, if the magnets have the same thickness, a configuration in which 2 magnets are stacked for the first magnet (31) and 3 magnets are stacked for the second magnet (32) may be adopted. Also, the first magnet (31) may be a single magnet, and the second magnet (32) may be configured by laminating 2 magnets with a thickness thinner than that of the first magnet (31).

[0092] In the present embodiment, the first magnet (31) and the second magnet (32) are all permanent magnets, or the first magnet (31) and the second magnet (32) are all electromagnets. However, the present invention is not limited to this. For example, the first magnet (31) may be an electromagnet, and the second magnet (32) may be a permanent magnet.

[0093] Although the embodiments and modifications have been described above, it will be understood that various modifications in form and detail are possible without departing from the spirit and scope of the claims. Furthermore, elements of the above embodiments, modifications, and other embodiments may be combined or substituted as appropriate. Furthermore, the terms "first," "second," "third," etc. in the specification and claims are used to distinguish between terms to which these terms are attached, and do not limit the number or order of those terms. [Industrial Applicability]

[0094] INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for magnetic refrigeration units and refrigeration devices. [Explanation of symbols]

[0095] 1 Refrigeration equipment 2 Heat medium circuit 10 Magnetic Refrigeration Unit 13 First magnetic working material 14 Second magnetic working material 16 Rotation Axis 21 First Rotating Body 22 Second rotating body 31 First Magnet 32 Second magnet 40 windings 50 Electromagnet

Claims

1. A rotating shaft (16), two first rotors (21) arranged at an interval in the axial direction of the rotary shaft (16) and rotating together with the rotary shaft (16); a second rotor (22) disposed between the two first rotors (21) and rotating together with the rotary shaft (16); a first magnetic working material (13) disposed between the first rotating body (21) and the second rotating body (22); a first magnet (31) provided on the first rotor (21) and facing the rotation shaft (16) in the axial direction to apply a magnetic field to the first magnetic working material (13); a second magnet (32) provided on the second rotor (22) and facing the rotation shaft (16) in the axial direction to apply a magnetic field to the first magnetic working material (13); The magnetomotive force F1 of the first magnet (31) and the magnetomotive force F2 of the second magnet (32) satisfy the condition F1<F2<2×F1. Magnetic refrigeration unit.

2. 2. The magnetic refrigeration unit of claim 1, two or more second rotors (22) are provided at intervals in the axial direction of the rotary shaft (16), A second magnetic working material (14) is disposed between the two second rotating bodies (22). Magnetic refrigeration unit.

3. 3. The magnetic refrigeration unit according to claim 1, the first magnet (31) and the second magnet (32) are made of materials having the same coercive force; The thickness t1 of the first magnet (31) and the thickness t2 of the second magnet (32) satisfy the condition t1<t2<2×t1. Magnetic refrigeration unit.

4. 3. The magnetic refrigeration unit according to claim 1, The first magnet (31) and the second magnet (32) are formed by electromagnets (50) that generate magnetomotive force when current is passed through a winding (40), The first magnet (31) and the second magnet (32) differ in at least one of the number of turns of the winding (40) and the value of the current passed therethrough. Magnetic refrigeration unit.

5. A magnetic refrigeration unit (10) according to claim 1 or 2; a heat medium circuit (2) for exchanging heat with the magnetic refrigeration unit (10),

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