Power transmission

Abstract

To increase a speed reduction ratio and increase pressure resistance without changing the number of poles of a magnet.SOLUTION: A power transmission device includes: a pole piece 25 that has a plurality of magnetic materials and rotates by modulating a magnetic flux between a driving side magnet 20 and a fixed magnet 40; and a sealing member 51 that divides the inside of a housing 15, 50 into a driving side space 113a on a side where the driving side magnet 20 is arranged and a driven side space 113b on a side where the fixed magnet 40 and the pole piece 25 are arranged, and seals fluid between the driving side space 113a and the driven side space 113b. The pole piece 25 and the fixed magnet 40 are cylindrical and are arranged coaxially and radially outward with respect to the driving side magnet 20. The sealing member 51 has a sealing cylindrical part 51b that is located radially outward with respect to the driving side magnet 20, and a sealing bottom face part 51c that closes the sealing cylindrical part 51b from the driving side space 113a side.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a power transmission device that transmits power by using magnetic force. [Background technology]

[0002] Conventionally, Patent Document 1 discloses a power transmission device in which magnets are arranged in a first mover and a second mover, and an intermediate yoke is arranged between the first mover and the second mover. A magnetic body is arranged in the intermediate yoke.

[0003] The first mover, the intermediate yoke, and the second mover are all cylindrical and arranged coaxially with each other. When the second mover rotates, the first mover rotates due to magnetic interaction. At this time, the second mover rotates. The pole ratio between the first mover and the second mover is the gear ratio.

[0004] The intermediate yoke is fitted into a cylindrical partition wall that separates a space on the first mover side from a space on the second mover side. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5958466 Summary of the Invention [Problem to be solved by the invention]

[0006] In contrast to the conventional techniques described above, there is a need to increase the torque, and one possible method to meet this need is to increase the reduction ratio by changing the number of poles of the magnet, but changing the number of poles of the magnet leads to a complex structure and increased costs.

[0007] Furthermore, in the above-mentioned conventional technology, since the intermediate yoke is fitted into the partition wall, it is difficult to increase the pressure resistance of the partition wall.

[0008] In particular, when this power transmission device is applied to an expansion valve used in a refrigeration cycle of an air conditioner for a vehicle, a significant reduction in size is required due to the limited installation space, making it difficult to ensure pressure resistance to high-pressure refrigerant. In addition, due to the limited installation space, the power transmission device may be placed horizontally or upside down, etc., in a manner that allows refrigerant to enter the power transmission device and cause resistance to rotation, so there is a growing need to increase the torque.

[0009] In view of the above, an object of the present invention is to increase the reduction ratio and improve pressure resistance without changing the number of poles of the magnet. [Means for solving the problem]

[0010] In order to achieve the above object, the power transmission device of the present invention comprises: A rotating drive magnet (20) having multiple poles; A housing (15, 50) that houses a drive side magnet; a fixed magnet (40) having a larger number of poles than the drive magnet and fixed to the housing; a pole piece (25) having a plurality of magnetic bodies and rotating by modulating magnetic flux between a driving magnet and a fixed magnet; a sealing member (51) that divides the inside of the housing into a driving-side space (113a) on the side where a driving-side magnet is arranged and a driven-side space (113b) on the side where a fixed magnet and a pole piece are arranged, and that seals a fluid between the driving-side space and the driven-side space, The pole piece and the fixed magnet are cylindrical and are disposed coaxially and radially outwardly of the driving magnet. The sealing member has a cylindrical sealing portion (51b) located radially outward from the driving-side magnet, and a bottom sealing portion (51c) that closes the cylindrical sealing portion from the driving-side space side.

[0011] According to this, since the fixed magnet is fixed to the housing and the pole piece is rotated, the reduction ratio can be made larger than that of a configuration in which the pole piece is fixed to the housing, because the number of poles of the pole piece is greater than the number of poles of the fixed magnet.

[0012] Since the sealing member can be made a member independent of the pole piece, the pressure resistance of the sealing member can be improved.

[0013] In addition, the reference symbols in parentheses for each means described in this column and in the claims indicate the correspondence with the specific means described in the embodiments described later. [Brief description of the drawings]

[0014] [Figure 1] 1 is an overall configuration diagram showing a vapor compression refrigeration cycle of a first embodiment. FIG. [Diagram 2] FIG. 2 is a cross-sectional view showing a first expansion valve of the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III of FIG. [Figure 4] FIG. 6 is a cross-sectional view showing a first expansion valve of a second embodiment. [Diagram 5] FIG. 5 is a cross-sectional view of FIG. 4 . [Figure 6] FIG. 11 is a cross-sectional view showing a first expansion valve of a third embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. [Figure 8] FIG. 11 is a cross-sectional view showing a first expansion valve of a fourth embodiment. [Figure 9] FIG. 11 is a cross-sectional view showing a first expansion valve of a fifth embodiment. [Figure 10] FIG. 13 is a block diagram showing a control system for a first expansion valve of the sixth embodiment. [Figure 11] 13 is a graph showing the results of a frequency analysis of an input current in the sixth embodiment. [Figure 12] 13 is a flowchart relating to lock determination control in the sixth embodiment. [Figure 13]FIG. 13 is a block diagram showing a control system for a first expansion valve of the seventh embodiment. [Figure 14] 23 is a graph showing the results of a frequency analysis of the envelope of the driving current in the seventh embodiment. [Figure 15] FIG. 13 is a block diagram showing a control system for a first expansion valve of the eighth embodiment. [Figure 16] 23 is a graph showing the results of a frequency analysis of a driving current in the eighth embodiment. [Figure 17] FIG. 13 is a block diagram showing a control system for a first expansion valve of the ninth embodiment. [Figure 18] 13 is a graph showing the results of a frequency analysis of a determination voltage in the ninth embodiment. [Figure 19] FIG. 23 is a block diagram showing a control system of a first expansion valve of the tenth embodiment. [Figure 20] 23 is a graph showing the results of a frequency analysis of a driving current in the tenth embodiment. [Figure 21] FIG. 23 is a block diagram showing a control system for a first expansion valve of an eleventh embodiment. [Figure 22] 23 is a graph showing the results of a frequency analysis of a line voltage in the eleventh embodiment. [Diagram 23] FIG. 23 is a cross-sectional view showing the configuration of a first expansion valve of a twelfth embodiment. [Figure 24] 23 is a graph showing the results of a frequency analysis of acceleration in the twelfth embodiment. [Diagram 25] FIG. 23 is a cross-sectional view of a motor section and a driving side magnet of a first expansion valve of a thirteenth embodiment. [Figure 26] FIG. 23 is a circuit diagram showing a part of an electric circuit of a motor unit according to a thirteenth embodiment. [Figure 27] 23 is a graph showing the relationship between the rotation angle in one phase of the motor section of the thirteenth embodiment and the induced voltage by the drive-side magnet. [Figure 28] FIG. 23 is a cross-sectional view of a motor section and a driving side magnet of a first expansion valve of a fourteenth embodiment. [Figure 29] FIG. 23 is a circuit diagram showing a part of an electric circuit of a motor unit according to a fourteenth embodiment. [Diagram 30] 23 is a graph showing the relationship between the rotation angle in one phase of the motor section of the fourteenth embodiment and the induced voltage by the drive-side magnet. [Diagram 31] FIG. 23 is a cross-sectional view of a motor section and a driving side magnet of a first expansion valve of a fifteenth embodiment. [Diagram 32] FIG. 23 is a circuit diagram showing a part of an electric circuit of a motor unit according to a fifteenth embodiment. [Diagram 33] FIG. 23 is a cross-sectional view of a motor section and a driving side magnet of a first expansion valve of a sixteenth embodiment. [Diagram 34] FIG. 23 is an explanatory diagram showing a part of the configuration of a first expansion valve in a seventeenth embodiment. [Diagram 35] FIG. 23 is a cross-sectional view showing a part of a first expansion valve of an eighteenth embodiment. [Diagram 36] 36 is a view taken along the arrow XXXVI in FIG. 35. [Figure 37] FIG. 23 is a plan view showing a reinforcing plate and a circuit portion according to the nineteenth embodiment. [Figure 38] FIG. 20 is a cross-sectional view showing a portion of a first expansion valve of a twentieth embodiment. [Figure 39] FIG. 28 is a plan view showing a reinforcing plate of the twentieth embodiment. [Diagram 40] FIG. 28 is a plan view showing a substrate according to a twentieth embodiment. [Diagram 41] FIG. 23 is a cross-sectional view showing a soldered portion between a substrate and a FET microcomputer in the twentieth embodiment. [Diagram 42] FIG. 23 is a cross-sectional view illustrating a deformed state of a substrate in the twentieth embodiment. [Diagram 43] FIG. 21 is a plan view showing a reinforcing plate of the twenty-first embodiment. [Diagram 44] FIG. 21 is a plan view showing a substrate according to a twenty-first embodiment. [Diagram 45] 10 is a flowchart showing a modified example of lock determination control. [Figure 46] 1 is a cross-sectional view showing a flow regulation valve to which a power transmission device is applied. [Figure 47] 1 is a cross-sectional view showing a small pump to which a power transmission device is applied. [Figure 48] FIG. 22 is a cross-sectional view showing a first expansion valve of a twenty-second embodiment. [Figure 49] FIG. 22 is a cross-sectional view showing a flow of magnetic flux in a first expansion valve of a twenty-second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a number of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, other embodiments described previously may be applied to the other parts of the configuration. In addition to combinations of parts that are specifically indicated as being possible in each embodiment, it is also possible to partially combine embodiments even if not indicated, as long as there is no particular problem with the combination.

[0016] (First embodiment) A first embodiment of the present disclosure will be described with reference to Fig. 1 to Fig. 3. A power transmission device 1 of the present embodiment is applied to a first expansion valve 113 and a second expansion valve 115 of a vapor compression refrigeration cycle 110. The vapor compression refrigeration cycle 110 is applied to a vehicle air conditioner 100 shown in Fig. 1. The vehicle air conditioner 100 is applied to an electric vehicle that obtains driving force for running the vehicle from an electric motor for running the vehicle.

[0017] The vehicle air conditioner 100 has three operation modes: a cooling mode for cooling the vehicle interior, a heating mode for heating the vehicle interior, and a dehumidification heating mode for heating the vehicle interior while dehumidifying it. In Fig. 1, the refrigerant flow in the cooling mode is indicated by a solid arrow, the refrigerant flow in the heating mode is indicated by a dashed arrow, and the refrigerant flow in the dehumidification heating mode is indicated by a two-dot chain arrow.

[0018] The vehicle air conditioner 100 includes a vapor compression refrigeration cycle 110 and a vehicle interior air conditioning unit 120 .

[0019] The vapor compression refrigeration cycle 110 has a compressor 111 , an indoor heat exchanger 112 , a first expansion valve 113 , an outdoor heat exchanger 114 , a second expansion valve 115 , an evaporator 116 , an electromagnetic opening / closing valve 117 , and an accumulator 118 .

[0020] The compressor 111 is an electric compressor that draws in, compresses, and discharges a refrigerant. A fluorocarbon refrigerant (e.g., R134a) is used as the refrigerant that circulates through the vapor compression refrigeration cycle. The vapor compression refrigeration cycle is a subcritical cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant.

[0021] The indoor heat exchanger 112 condenses the refrigerant discharged from the compressor 111 by heat exchange with the air flowing in the vehicle interior air conditioning unit 120. The first expansion valve 113 reduces the pressure and expands the refrigerant condensed in the indoor heat exchanger 112. The outdoor heat exchanger 114 exchanges heat between the refrigerant flowing out from the first expansion valve 113 and the outside air. The second expansion valve 115 reduces the pressure and expands the refrigerant flowing out from the outdoor heat exchanger 114. The evaporator 116 evaporates the refrigerant reduced in pressure and expanded by the second expansion valve 115 by heat exchange with the air flowing in the vehicle interior air conditioning unit 120. The solenoid opening / closing valve 117 is a solenoid valve that opens and closes a refrigerant flow path that leads the refrigerant flowing out from the outdoor heat exchanger 114 to the accumulator 118, bypassing the second expansion valve 115 and the evaporator 116. The accumulator 118 separates the refrigerant evaporated in the evaporator 116 and the refrigerant that has passed through the electromagnetic on-off valve 117 into gas and liquid.

[0022] The vehicle interior air conditioning unit 120 is disposed in the vehicle interior, and forms an air passage therein. In the air passage in the vehicle interior air conditioning unit 120, a blower 121, an evaporator 116, an exterior heat exchanger 114, and an air mix door 122 are disposed. The blower 121 is an electric blower that blows air into the air passage in the vehicle interior air conditioning unit 120. The evaporator 116 is disposed downstream of the air flow from the blower 121. The interior heat exchanger 112 is disposed downstream of the air flow from the evaporator 116. The air mix door 122 adjusts the flow rate ratio between the air flowing to the interior heat exchanger 112 and the air flowing bypassing the interior heat exchanger 112. The vehicle interior air conditioning unit 120 blows out the air whose temperature has been adjusted by the air mix door 122 into the vehicle interior.

[0023] In the cooling mode of the vehicle air conditioner 100, the electromagnetic on-off valve 117 is closed, and the air mix door 122 closes the air flow path to the indoor heat exchanger 112. Therefore, the refrigerant discharged from the compressor 111 passes through the indoor heat exchanger 112 without being heat exchanged therein, flows through the first expansion valve 113, the outdoor heat exchanger 114, the second expansion valve 115, the evaporator 116, and the accumulator 118 in this order, and returns from the accumulator 118 to the compressor 111.

[0024] At this time, the first expansion valve 113 is opened to a degree that does not throttle the refrigerant flow, and the second expansion valve 115 is opened to a degree that throttles the refrigerant flow, so that the refrigerant is condensed in the outdoor heat exchanger 114 and evaporated in the evaporator 116.

[0025] In the heating mode of the vehicle air conditioner 100, the electromagnetic on-off valve 117 is opened, the second expansion valve 115 is closed to block the flow of refrigerant, and the air mix door 122 is opened to allow air to flow to the indoor heat exchanger 112. Therefore, the refrigerant discharged from the compressor 111 flows through the indoor heat exchanger 112, the first expansion valve 113, the outdoor heat exchanger 114, the electromagnetic on-off valve 117, and the accumulator 118 in this order, and returns from the accumulator 118 to the compressor 111. At this time, the first expansion valve 113 is opened to a valve opening degree that throttles the flow of refrigerant, and the second expansion valve 115 is closed, so that the refrigerant is condensed in the indoor heat exchanger 112, the refrigerant is evaporated in the outdoor heat exchanger 114, and no refrigerant flows through the evaporator 116.

[0026] In the dehumidification heating mode of the vehicle air conditioner 100, the electromagnetic on-off valve 117 is closed, and the air mix door 122 is opened to allow air to flow to the indoor heat exchanger 112. Therefore, the refrigerant discharged from the compressor 111 flows through the indoor heat exchanger 112, the first expansion valve 113, the outdoor heat exchanger 114, the second expansion valve 115, the evaporator 116, and the accumulator 118 in this order, and returns to the compressor 111 from the accumulator 118.

[0027] At this time, the first expansion valve 113 and the second expansion valve 115 are opened to a valve opening degree that throttles the refrigerant flow, so that the refrigerant is condensed in the indoor heat exchanger 112 and evaporated in the outdoor heat exchanger 114 .

[0028] 2, the first expansion valve 113 has the power transmission device 1, a driving side mechanism unit 10, and a driven side mechanism unit 35. The first expansion valve 113 is disposed vertically in the vehicle. The vertical disposition means that the axial direction of the valve body 48 is approximately parallel to the vertical direction of the vehicle, and the driving side mechanism unit 10 is disposed on the upper side of the vehicle relative to the driven side mechanism unit 35.

[0029] The power transmission device 1 transmits the driving force generated by the drive mechanism 10 to the driven mechanism 35 by using magnetic force.

[0030] The drive side mechanism section 10 has a motor section 11 and a motor case 15. The motor section 11 is a three-phase motor 11a, and has a stator 12, a rotor 13, and a shaft 14. The shaft 14 is an input shaft of the power transmission device 1, and rotates integrally with the rotor 13. The motor case 15 houses the motor section 11.

[0031] The stator 12 is fixed to a motor case 15. The stator 12 has a stator coil 12a. In this example, the number of slots Ns of the stator 12 is six.

[0032] The rotor 13 is cylindrical, and the stator 12 is disposed inside the rotor 13. As shown in Fig. 3, the rotor 13 has a plurality of pairs of magnets, each of which has an N pole 13n and an S pole 13s, disposed along the circumferential direction. In this example, there are four N poles 13n and four S poles 13s, so the number of poles Pr of the rotor 13 is eight. The stator 12 and the rotor 13 output a driving force that rotates the shaft 14 by electromagnetic force.

[0033] The motor case 15 is formed with an axis alignment portion 15a for axial alignment (centering) between the shaft 14 of the drive side mechanism portion 10 and the rotating member 41 of the driven side mechanism portion 35. The axis alignment portion 15a is fitted into the main body portion 50 of the driven side mechanism portion 35.

[0034] A circuit section 70 is housed within the motor case 15. The circuit section 70 has a circuit board on which a plurality of electronic components for controlling the three-phase motor 11a, which is the motor section 11, are mounted.

[0035] The driven side mechanism portion 35 has a rotating member 41 , a valve body 48 , a bearing member 49 and a main body portion 50 .

[0036] The rotating member 41, the valve body 48, and the bearing member 49 are housed in a main body 50. The main body 50, together with the motor case 15, constitutes the housing of the first expansion valve 113. In the main body 50, a valve chamber 52, an inlet side connection port 53, an outlet side connection port 54, and a valve seat 55 are formed.

[0037] The rotating member 41 is an output shaft of the power transmission device 1, and is rotated by the driving force transmitted from the drive side mechanism portion 10. The rotating member 41 is a rod-shaped member, and is arranged coaxially with the shaft 14. An engagement groove 41a is formed at the end of the rotating member 41 opposite to the drive side mechanism portion 10. The rotating member 41 is rotatably supported by a bearing member 49 fixed to the main body portion 50.

[0038] The valve body 48 is a rod-shaped member disposed within the valve chamber 52. The valve body 48 is disposed coaxially with the rotating member 41. A protruding piece 48a of the valve body 48 meshes with the meshing groove 41a of the rotating member 41. As a result, the rotational force of the rotating member 41 is transmitted to the valve body 48.

[0039] The protruding piece 48a is formed at one end of the valve body 48. A male thread is formed on the outer circumferential surface of the valve body 48. The male thread of the valve body 48 is screwed into a screw hole 50a formed in the main body 50 to form a screw mechanism. As a result, when the valve body 48 rotates, the valve body 48 moves in the axial direction.

[0040] The valve body 48 is formed of a plurality of members. Specifically, the valve body 48 is composed of a male thread member 481 located on the rotating member 41 side and having the above-mentioned male thread formed therein, a valve seat side member 482 located on the valve seat 55 side, and a ball 483 disposed between the two members 481, 482. By disposing the ball 483 between the two members 481, 482, the valve seat side member 482 of the valve body 48 moves in the axial direction without rotating.

[0041] A valve seat side member 482 of the valve body 48, which serves as a ball receiving member, is biased by a coil spring 47 in a direction away from the valve seat 55 in the axial direction of the valve body 48.

[0042] As the valve element 48 moves in the axial direction, the valve element 48 comes into contact with or separates from the valve seat 55, thereby opening and closing the valve chamber 52. In the valve chamber 52, as the valve element 48 separates from the valve seat 55, the refrigerant flows from the inlet side connection port 53 to the outlet side connection port 54 and is decompressed and expanded.

[0043] The power transmission device 1 includes a non-contact connection portion 60. The non-contact connection portion 60 includes a magnetic gear 60b and a sealing plate 51. The magnetic gear 60b includes a driving side magnet 20, a pole piece 25, and a fixed magnet .

[0044] The driving side magnet 20 rotates integrally with the shaft 14 of the motor unit 11. The pole piece 25 modulates the magnetic flux between the driving side magnet 20 and the fixed magnet 40, and rotates integrally with the rotating member 41. The fixed magnet 40 is fixed to the main body 50 of the first expansion valve 113.

[0045] The driving-side magnet 20 is cylindrical, and is joined to the outer circumferential surface of the rotor 13 of the motor unit 11 via a cylindrical interposed member 21. In other words, the motor unit 11 is disposed inside the driving-side magnet 20. The interposed member 21 is formed of a magnetic material.

[0046] The driving side magnet 20 has at least one pair of magnets, each consisting of an N pole 20n and an S pole 20s, arranged along the circumferential direction. In this example, there is one N pole 20n and one S pole 20s, so the number of poles Pin of the driving side magnet 20 is two.

[0047] The number of poles Pin of the drive-side magnet 20 is equal to the number of poles Pr of the rotor 13 minus the number of slots Ns of the stator 12. In this example, the number of poles Pr of the rotor 13 is 8, and the number of slots Ns of the stator 12 is 6, so the number of poles Pin of the drive-side magnet 20 is 2.

[0048] The sealing plate 51 is a sealing member that divides the internal space of the first expansion valve 113 into a driving side space 113a and a driven side space 113b, and seals the driven side space 113b. The driving side space 113a is a space on the driving side mechanism unit 10 side, and the driven side space 113b is a space on the driven side mechanism unit 35 side.

[0049] The sealing plate 51 prevents the refrigerant (high pressure refrigerant) present in the driven side space 113b from leaking into the driving side space 113a. In this example, the sealing plate 51 is made of a non-magnetic material (for example, SUS305).

[0050] The sealing plate 51 is disk-shaped with a central portion recessed downward, and has a sealing upper surface portion 51a, a sealing cylindrical portion 51b, and a sealing bottom surface portion 51c. The sealing upper surface portion 51a is annular plate-shaped, and its outer edge portion is fixed to the main body portion 50 of the first expansion valve 113. The sealing cylindrical portion 51b is cylindrical, and is located on the outer diameter side of the drive-side magnet 20. The sealing bottom surface portion 51c is located below the drive-side magnet 20, and blocks the sealing cylindrical portion 51b from the drive-side space 113a side.

[0051] The sealing bottom portion 51c is a disk-shaped portion curved downward at the center. The corners that form the boundary between the sealing cylindrical portion 51b and the sealing bottom portion 51c are not right angles but are rounded with a predetermined radius of curvature to improve pressure resistance.

[0052] In order to improve pressure resistance, the sealing plate 51 has a sealing upper surface portion 51a, a sealing cylindrical portion 51b, and a sealing bottom surface portion 51c which are integrally formed.

[0053] The sealing bottom surface portion 51c is disposed in the gap between the shaft 14 and the rotating member 41 in the axial direction of the shaft 14 and the rotating member 41. That is, the sealing bottom surface portion 51c is disposed in a location where there are few torque generation points. This makes it easy to ensure the torque resistance and pressure resistance of the sealing plate 51.

[0054] The pole piece 25 is cylindrical, and is disposed on the outer diameter side of the sealing cylindrical portion 51b of the sealing plate 51. The pole piece 25 is joined to the rotating member 41 of the driven side mechanism portion .

[0055] The fixed magnet 40 is cylindrical and is disposed on the outer diameter side of the pole piece 25. The fixed magnet 40 is fitted into a cylindrical main body cylindrical portion 50b (in other words, the housing cylindrical portion) of the main body portion 50 (in other words, the housing) via a cylindrical back yoke 56. The back yoke 56 and the main body cylindrical portion 50b are formed of a magnetic material.

[0056] The fixed magnet 40 has a plurality of pairs of magnets, each consisting of an N pole 40n and an S pole 40s, arranged at approximately equal intervals along the circumferential direction. The number of poles Pf of the fixed magnet 40 is greater than the number of poles Pin of the drive-side magnet 20. In this example, there are 20 each of the N poles 40n and S poles 40s, so the number of poles Pf of the fixed magnet 40 is 40.

[0057] The axial length L2 of the fixed magnet 40 is longer than the axial length L1 of the drive-side magnet 20. This makes it possible to increase the area between the fixed magnet 40 and the pole piece 25, where there are many torque generating points.

[0058] The pole piece 25 has a plurality of magnetic material parts 25a and a plurality of non-magnetic material parts 25b. The magnetic material parts 25a and the non-magnetic material parts 25b are frustum-shaped, and the magnetic material parts 25a are arranged at approximately equal intervals along the circumferential direction. The non-magnetic material parts 25b are arranged between the magnetic material parts 25a. For example, the magnetic material parts 25a are made of a soft magnetic material (e.g., an iron-based metal), and the non-magnetic material parts 25b are made of a non-magnetic material (e.g., stainless steel or resin).

[0059] The number of poles Pp of the pole piece 25 is the same as the sum of the number of poles Pin of the drive-side magnet 20 and the number of poles Pf of the fixed magnet 40. In this example, the number of poles Pin of the drive-side magnet 20 is 2, and the number of poles Pf of the fixed magnet 40 is 40, so the number of poles Pp of the pole piece 25 is 42. That is, there are 21 magnetic material portions 25a and 21 non-magnetic material portions 25b. That is, the number Npp of the magnetic material portions 25a has the following relationship with the number of poles Pin of the drive-side magnet 20 and the number of poles Pf of the fixed magnet 40. Npp=(Pin+Pf) / 2 The axial length Lp of the pole piece 25 is shorter than the axial length L2 of the fixed magnet 40. This reduces magnetic flux leakage in the axial direction at the pole piece 25, and improves the transmission torque.

[0060] The second expansion valve 115 has a configuration similar to that of the first expansion valve 113 .

[0061] Next, the operation of the power transmission device 1 in this embodiment will be described. When the shaft 14 of the motor unit 11 rotates and the driving-side magnet 20 rotates integrally with it, the pole piece 25 rotates in the same direction as the driving-side magnet 20 due to the magnetic interaction between the driving-side magnet 20 and the fixed magnet 40.

[0062] The reduction ratio at this time is equal to the value obtained by dividing the number of poles Pp of the pole piece 25 by the number of poles Pin of the drive-side magnet 20. Since the number of poles Pp of the pole piece 25 is greater than the number of poles Pin of the drive-side magnet 20, the rotation speed of the pole piece 25 is smaller than the rotation speed of the drive-side magnet 20.

[0063] In this example, the number of poles Pp of the pole piece 25 is 42, and the number of poles Pin of the drive-side magnet 20 is 2, so the reduction ratio is 21.

[0064] In contrast, in a configuration in which the pole piece 25 is fixed and a magnet with the same number of poles as the fixed magnet 40 is joined to the rotating member 41 of the driven side mechanism unit 35 and rotated (hereinafter, this configuration will be referred to as the comparative example), the reduction ratio is 20.

[0065] Since the number of poles Pp of the pole piece 25 is greater than the number of poles Pf of the fixed magnet 40, in this embodiment in which the pole piece 25 is rotated, the reduction ratio is greater than in the comparative example in which a magnet with the same number of poles as the fixed magnet 40 is rotated.

[0066] In this embodiment in which the pole piece 25 is rotated, the pole piece 25 is an independent member from the sealing plate 51. Therefore, the pressure resistance of the sealing plate 51 can be improved compared to the conventional structure in which the pole piece does not rotate and is embedded in the sealing plate.

[0067] In this embodiment, the sealing plate 51 has a cylindrical sealing portion 51b and a bottom sealing portion 51c. As a result, the sealing plate 51 has a disk shape with a central portion recessed toward the driven-side mechanism portion 35. Therefore, the sealing plate 51 can be disposed as a member independent of the pole piece 25, and the pressure resistance of the sealing plate 51 can be improved.

[0068] In this embodiment, the number Npp of the magnetic bodies 25a of the pole piece 25 has the following relationship with the number of poles Pin of the drive-side magnet 20 and the number of poles Pf of the fixed magnet 40. Npp=(Pin+Pf) / 2 This allows the rotational force of the drive-side magnet 20 to be transmitted to the pole piece 25.

[0069] In this embodiment, the fixed magnet 40 is fixed to the inner circumferential surface of the back yoke 56, and the back yoke 56 is fixed to the inner circumferential surface of the cylindrical main body portion 50b. This makes it easier to press-fit the fixed magnet 40 into the main body portion 50.

[0070] In this embodiment, the stator 12 and the rotor 13 are disposed inside the drive-side magnet 20. This allows the size of the first expansion valve 113 in the axial direction to be reduced.

[0071] In this embodiment, an interposition member 21 is disposed between the rotor 13 and the drive-side magnet 20. This allows the rotor 13 to be disposed inside the drive-side magnet 20 in a favorable manner.

[0072] In this embodiment, in the axial direction of the drive-side magnet 20, the pole piece 25 is shorter than the drive-side magnet 20 and the fixed magnet 40. This reduces magnetic flux leakage in the axial direction at the pole piece 25, and improves the transmission torque.

[0073] In the axial direction of the drive-side magnet 20, the fixed magnet 40 is longer than the drive-side magnet 20. This makes it possible to increase the area between the pole piece 25, where there are many torque generating points, and the fixed magnet 40.

[0074] In this embodiment, in the axial direction of the driving-side magnet 20, the driving-side magnet 20 is longer than the pole piece 25 and shorter than the fixed magnet 40. This reduces magnetic flux leakage in the axial direction at the pole piece 25 and ensures a large area of ​​the surface where torque is generated, thereby improving the transmission torque.

[0075] In this embodiment, the axis alignment portion 15a of the motor case 15 is fixed to the main body cylindrical portion 50b, thereby aligning the axis of the driving side magnet 20 with the pole piece 25. This makes it possible to easily align the axis of the driving side magnet 20 with the pole piece 25.

[0076] In this embodiment, the cylindrical sealing portion 51b is formed from a single non-magnetic member, which makes it possible to ensure pressure resistance with a thin wall, thereby reducing magnetic resistance.

[0077] In this embodiment, the sealing top surface portion 51a, the sealing cylindrical portion 51b, and the sealing bottom surface portion 51c of the sealing plate 51 are formed from a single non-magnetic material, thereby making it possible to further reduce the magnetic resistance.

[0078] Second embodiment In the above embodiment, the motor section 11 is arranged inside the driving side magnet 20, but in this embodiment, as shown in Figures 4 and 5, the motor section 11 is arranged outside the driving side magnet 20 and on the opposite side of the driven side mechanism section 35 from the driving side magnet 20.

[0079] In this embodiment as well, the same effects as those of the above embodiment can be achieved.

[0080] Third embodiment In the above embodiment, the rotor 13 of the motor unit 11 and the drive side magnet 20 of the magnetic gear 60b are separate components, but in this embodiment, as shown in Figures 6 and 7, the drive side magnet 20 also serves as the rotor 13 of the motor unit 11.

[0081] That is, the stator 12 is disposed inside the drive-side magnet 20 and rotates the drive-side magnet 20 as a rotor, thereby making it possible to reduce the number of parts and simplify the configuration.

[0082] (Fourth embodiment) In this embodiment, as shown in FIG. 8, the pole piece 25 is located above an imaginary line lv connecting the upper end of the driving-side magnet 20 and the upper end of the fixed magnet 40.

[0083] In other words, in the axial direction of the driving-side magnet 20, the pole piece 25 is located on the opposite side of the bearing member 49 from the imaginary line lv connecting the end of the driving-side magnet 20 opposite the bearing member 49 and the end of the fixed magnet 40 opposite the bearing member 49. This generates a magnetic action that presses the pole piece 25 and the rotating member 41 downward (towards the bearing member 49), thereby stabilizing the rotation of the rotating member 41.

[0084] Fifth embodiment In this embodiment, as shown in Fig. 9, a driving side bearing portion 51d and a driven side bearing portion 51e are formed on the sealing bottom surface portion 51c of the sealing plate 51. The driving side bearing portion 51d rotatably supports the lower end portion of the shaft 14. The driven side bearing portion 51e rotatably supports the upper end portion of the rotating member 41. This makes it possible to stabilize the rotation of the shaft 14 and the rotating member 41.

[0085] Sixth embodiment In this embodiment, a specific configuration of the circuit unit 70 of the first embodiment is shown. As shown in Fig. 10, the three-phase motor 11a, which is the motor unit 11, and the battery B are electrically connected to the circuit unit 70. The battery B supplies power to various electric devices of the vehicle, and is, for example, a chargeable and dischargeable secondary battery (in this embodiment, a lithium ion battery). The circuit unit 70 receives input power from the battery B and outputs a drive current for driving the three-phase motor 11a.

[0086] The circuit unit 70 has electronic components such as an ECU for controlling the operation of the first expansion valve 113, and functions as a control unit for the operation of the first expansion valve 113. The circuit unit 70 has a lock determination unit 71. The lock determination unit 71 constitutes part of the control unit, and determines whether or not the power generated in the drive side mechanism unit 10 is not transmitted to the driven side mechanism unit 35 during the operation of the first expansion valve 113, causing a lock on the driven side.

[0087] Specifically, the lock determination unit 71 executes a lock determination control program shown in the flowchart of Fig. 12 to determine whether the driven side is locked and an operation error has occurred in the valve body 48. The details of the lock determination control program will be described later.

[0088] An input current sensor 73a is connected to the circuit section 70 according to the present embodiment. The input current sensor 73a is a sensor for measuring the value of the input current input from the battery B to the circuit section 70. In the first embodiment, the lock determination section 71 performs frequency analysis using a fast Fourier transform on the detection result of the input current sensor 73a, and determines whether or not a lock has occurred on the driven side based on the analysis result.

[0089] Here, we will explain the torque fluctuation (i.e., the fluctuation of the rotational load on the drive-side magnet 20) when the magnetic gear 60b is in the standard state. The standard state refers to a state in which power is suitably transmitted between the drive-side magnet 20 and the pole piece 25, and both the drive-side magnet 20 and the pole piece 25 rotate smoothly.

[0090] In the standard state, the fluctuation in the rotational load between the drive magnet 20 and the pole piece 25 during one rotation occurs at the point where the number of pole pairs of the drive magnet 20 and the number of pole pairs of the fixed magnet 40 become the least common multiple.

[0091] For example, in the standard state, if the driving magnet 20 rotates 21 times per second clockwise and the pole piece 25 rotates once per second clockwise, the relative rotational speed difference between the driving magnet 20 and the pole piece 25 is 20 rotations per second. Therefore, the fluctuation of the rotational load in the standard state occurs at 200 Hz.

[0092] Next, a description will be given of the fluctuation of the rotation load when the magnetic gear 60b is in a locked state. The locked state means that the driving magnet 20 is freely rotatable, but the fixed magnet 40 is fixed for some reason.

[0093] If we consider the locked state using the example of the standard state described above, the action of the fixed magnet 40 and pole piece 25 causes two-pole spatial harmonics to be fixed in the gap between the drive-side magnet 20 and pole piece 25, resulting in a fluctuation in the rotational load of 21 Hz due to the two poles of the drive-side magnet and the rotational speed of the drive shaft.

[0094] As described above, the driving-side magnet 20 is integrated with the rotor 13 of the motor unit 11 via the intervening member 21 and the shaft 14. For this reason, when a fluctuation in the rotational load occurs in the locked state, the fluctuation in the rotational load of the driving-side magnet 20 appears as a fluctuation in the input current due to the speed feedback related to the motor unit 11.

[0095] Therefore, by subjecting the detection result of the input current sensor 73a to frequency analysis by the lock determination unit 71, it is possible to detect the occurrence of a lock of the pole piece 25 or the like.

[0096] Furthermore, since the frequency of the fluctuation in the input current that occurs in a locked state is different from the frequency of the fluctuation in the drive current to the motor unit 11, it is possible to detect that the pole piece 25, etc. is locked by identifying the frequency of the fluctuation in the input current.

[0097] When comparing the frequency analysis result for the input power in the standard state with the locked analysis result RL, by focusing on a certain specific frequency (hereinafter referred to as the specific frequency), it becomes easier to determine that a lock has occurred in the pole piece 25, etc.

[0098] Fig. 11 is a graph showing an example of a locked-state analysis result RL obtained by performing a frequency analysis on the detection result of the input current sensor 73a by the lock determination unit 71. As can be seen from the locked-state analysis result RL shown in Fig. 11, a peak of the input current appears at a specific frequency fs, which is due to a fluctuation in the rotation load caused by the locking of the pole piece 25 or the like.

[0099] The peak of the specific frequency fs can be more clearly identified by satisfying the condition that the number of poles Pm (e.g., 8) of the motor unit 11 is different from the number of poles Pin (e.g., 2) of the drive-side magnet 20. The peak of the specific frequency fs can be more clearly identified as the number of poles Pin of the drive-side magnet 20 is smaller.

[0100] In this way, according to the power transmission device 1 of this embodiment, by comparing the standard state and the locked state with respect to the results of frequency analysis of the input current performed by the lock determination unit 71, it is possible to easily determine whether or not a lock has occurred in the pole piece 25, etc.

[0101] Next, the contents of the lockup determination control in the power transmission device 1 according to this embodiment will be described with reference to Fig. 12. As described above, the first expansion valve 113 including the power transmission device 1 is mounted as a component of the vapor compression refrigeration cycle 110 in the vehicle air conditioner 100 mounted on the vehicle. Therefore, the lockup determination control is executed by the lockup determination unit 71 when the vehicle is started.

[0102] First, in step S1, which is executed when the vehicle is started, the motor unit 11 constituting the drive side mechanism unit 10 is driven. At this time, the motor unit 11 operates the rotor 13 at a constant rotation speed.

[0103] In step S2, a signal analysis process is performed on the detection result of the input current in step S1. That is, the lock determination unit 71 performs a frequency analysis using a fast Fourier transform on the detection result of the input current detected when the motor unit 11 is driven in step S1.

[0104] In step S3, it is determined whether or not a lock determination condition is satisfied. The lock determination condition means a condition for determining that the pole piece 25 or the like is locked, and in the first embodiment, the result of frequency analysis of the input current is that the value of the input current at a specific frequency fs exceeds a reference value.

[0105] The reference value is determined based on a standard state, for example, based on the value of the input current at a specific frequency fs as a result of frequency analysis of the input current in the standard state.

[0106] If the result of the frequency analysis of the input current indicates that the value of the input current at the specific frequency fs exceeds the reference value, the process proceeds to step S12; otherwise, the process proceeds to step S4.

[0107] In step S4, it is determined whether or not an air conditioner start signal has been received. The air conditioner start signal is a control signal output from an air conditioning control device constituting a vehicle air conditioner, and is output when, for example, an operation to start air conditioning operation is performed using an operation panel of the vehicle. If the air conditioner start signal has not been received, the process waits until the air conditioner start signal is received, and if the air conditioner start signal is received, the process proceeds to step S5.

[0108] When the process proceeds to step S5, as part of the initialization process associated with the start of the air conditioning operation in the vehicle air conditioner, the motor unit 11 constituting the drive side mechanism unit 10 is driven. In this case, as in step S1, the motor unit 11 operates the rotor 13 at a constant rotation speed.

[0109] In step S6, a signal analysis process is performed on the detection result of the input current in step S5. That is, the lock determination unit 71 performs a frequency analysis using a fast Fourier transform on the detection result of the input current detected when the motor unit 11 is driven in step S5.

[0110] In step S7, it is determined whether or not the lock determination condition is satisfied, similarly to step S3. If the result of the frequency analysis of the input current indicates that the input current value at the specific frequency fs exceeds the reference value, the process proceeds to step S12; otherwise, the process proceeds to step S8.

[0111] In step S8, since it is determined in steps S4 to S7 that the pole piece 25 or the like has not been locked, the air conditioning operation in the vehicle air conditioner is started based on the air conditioner start signal.

[0112] At this time, in the vehicle air conditioner, an operation mode is selected based on detection signals from the group of sensors for controlling the air conditioner and operation signals from the operation panel, and control signals are output to each component of the vehicle air conditioner based on the selected operation mode. Therefore, a drive control signal for the motor unit 11 is output to the first expansion valve 113 in order to realize opening control based on the operation mode.

[0113] In step S9, during air conditioning operation of the vehicle air conditioner, the motor unit 11 constituting the drive side mechanism unit 10 is driven. Since the air conditioning operation of the vehicle air conditioner is being executed, a control signal for realizing a throttle opening degree according to the state of the air conditioning operation is output to the motor unit 11 of the first expansion valve 113, and the motor unit 11 operates the rotor 13 based on the control signal.

[0114] In step S10, a signal analysis process is performed on the detection result of the input current associated with the opening control of the first expansion valve 113 in step S9. That is, the lock determination unit 71 performs a frequency analysis using a fast Fourier transform on the detection result of the input current detected when the motor unit 11 is driven in step S10.

[0115] In step S11, it is determined whether or not the lock determination condition is met, similarly to steps S3 and S7. If the result of the frequency analysis of the input current indicates that the input current value at the specific frequency fs exceeds the reference value, the process proceeds to step S12, otherwise, the process returns to step S9 to continue the lock determination of the pole piece 25, etc. during air conditioning operation.

[0116] When the process proceeds to step S12, a lock occurrence signal is output based on the fact that it is determined in steps S3, S7, and S11 that the lock determination conditions are met. The lock occurrence signal is a signal indicating that the pole piece 25 or the rotating member 41 is stuck and locked. After the lock occurrence signal is output, the lock determination control ends.

[0117] The lock occurrence signal may be output to, for example, an air conditioning control device of a vehicle air conditioner or a control device on the vehicle body side. When the lock occurrence signal is output to the air conditioning control device, the air conditioning control device stops the operation of the power transmission device 1 (i.e., the operation of the first expansion valve 113). Also, if the lock determination condition is satisfied in steps S7 and S11, the air conditioning operation of the vehicle air conditioner may be stopped.

[0118] According to the power transmission device 1 of this embodiment, by executing the lock determination control shown in Fig. 12, it is possible to constantly monitor whether or not a lock has occurred in the pole piece 25, etc. In other words, when a lock has occurred in the pole piece 25, etc., it is possible to recognize the occurrence of the lock and take measures to eliminate the lock.

[0119] As described above, according to the power transmission device 1 of this embodiment, the shaft 14 of the drive side mechanism 10 and the rotating member 41 of the driven side mechanism 35 are connected in a non-contact manner using magnetic force by the magnetic gear 60b, which is the non-contact connecting portion 60. For this reason, if the pole piece 25 and the rotating member 41 are locked while the drive side magnet 20 is rotating together with the shaft 14, the rotational load of the shaft 14 and the drive side magnet 20 will periodically fluctuate due to the influence of the magnetic force acting between the drive side magnet 20 and the fixed magnet 40.

[0120] According to the power transmission device 1, by using the fluctuation in the rotational load in the drive side mechanism section 10, it is possible to determine whether or not the pole piece 25 in the separately partitioned driven side mechanism section 35 has locked.

[0121] 2 and 3, the non-contact coupling unit 60 in the power transmission device 1 is configured with a magnetic gear 60b having a pole piece 25 disposed between the driving-side magnet 20 and the fixed magnet 40. In this configuration, the number of poles Pm of the motor unit 11 is different from the number of poles Pin obtained by adding up the N poles 20n and S poles 20s of the driving-side magnet 20.

[0122] As a result, in the frequency analysis in the lock determination control shown in FIG. 12, the specific frequency fs can be clearly distinguished, and the accuracy of determining whether or not the lock determination condition is satisfied can be improved.

[0123] Then, as shown in Figures 10 to 12, in the power transmission device 1 according to this embodiment, a frequency analysis is performed on the input current of the motor unit 11, and when the input current at a specific frequency fs exceeds a reference value, it is determined that a lock of the pole piece 25 has occurred.

[0124] This makes it possible to accurately determine whether the pole piece 25 in the driven-side mechanism portion 35, which is separated from the drive-side mechanism portion 10, is locked based on the fluctuation in the input current, which is relatively easy to detect.

[0125] (Modification of the sixth embodiment) In the above-described sixth embodiment, the number of poles Pm of the motor unit 11 and the number of poles Pin of the drive-side magnet 20 are configured to be different from each other, and the value of the specific frequency fs in the locked-state analysis result RL is used to determine whether or not the lock determination condition is satisfied.

[0126] As a modification of the sixth embodiment, the lock determination condition can be configured to use two types of specific frequency fs and specific frequency fss values.

[0127] One of the conditions for adopting this embodiment is that 1 / 2 of the number of poles Pm of the motor unit 11 is different from the least common multiple of 1 / 2 of the number of poles Pin of the drive-side magnet 20 and 1 / 2 of the number of poles Pf of the fixed magnet 40. By satisfying this condition, it is possible to determine whether or not the lock determination condition is satisfied, using the peak at a specific frequency fs in the locked state analysis result RL shown in Fig. 11.

[0128] Furthermore, the value of the specific frequency fss can be utilized by satisfying the condition that the least common multiple of the number of poles Pm of the motor section 11 and the number of slots Ns in the motor section 11 is different from the least common multiple of 1 / 2 the number of poles Pin of the driving side magnet 20 and 1 / 2 the number of poles Pf of the fixed magnet 40. As shown in Fig. 11, the specific frequency fss indicates a frequency higher than the specific frequency fs.

[0129] In this way, by using the value of the specific frequency fs and the value of the specific frequency fss as the lock determination condition, it is possible to determine with higher accuracy whether or not a lock has occurred in the pole piece 25, etc.

[0130] Seventh embodiment Next, a seventh embodiment different from the above-mentioned embodiment will be described with reference to Fig. 13 and Fig. 14. In the seventh embodiment, the method of determining whether the pole piece 25 or the like is locked is different from that of the above-mentioned embodiment. The basic configurations of the driving side mechanism unit 10, the driven side mechanism unit 35, etc. are the same as those of the above-mentioned embodiment, so a repeated description will be omitted.

[0131] 13, in the power transmission device 1 according to the seventh embodiment, a three-phase motor 11a is adopted as the motor unit 11 constituting the drive-side mechanism unit 10. The circuit unit 70 according to the seventh embodiment has a lock determination unit 71, a three-phase inverter circuit 72, and a drive current sensor 73b.

[0132] The lock determination unit 71 is the same as that in the sixth embodiment. Furthermore, the drive current sensor 73b is a sensor for detecting the drive current supplied to the stator coil 12a of each phase in the three-phase motor 11a.

[0133] The three-phase inverter circuit 72 is a power conversion circuit that converts the DC power supplied from the battery B into AC power, and is configured by combining a plurality of MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors).

[0134] As shown in FIG. 13, the three-phase inverter circuit 72 is electrically connected to the battery B and the three-phase motor 11a, and converts the DC power of the battery B into three-phase AC power to supply it to the stator coil 12a of each phase of the three-phase motor 11a.

[0135] The three-phase inverter circuit 72 according to the seventh embodiment includes a rectifier circuit (RCF) and an envelope detector (ENV). The rectifier circuit generates a three-phase AC waveform by converting a three-phase signal into an analog signal, and full-wave rectifies the three-phase AC waveform. The envelope detector detects and outputs the envelope of the full-wave rectified waveform.

[0136] Next, the lock determination control in the seventh embodiment will be described with reference to Fig. 14. When the non-contact connection part 60 is in a locked state, the driving side magnet 20 rotates, but the pole piece 25 is stopped. Therefore, the fluctuation of the rotation load between the driving side magnet 20 and the pole piece 25 occurs at a constant cycle due to magnetic interaction, as in the above-mentioned embodiments.

[0137] For this reason, fluctuations in the rotation load cause fluctuations in the rotation speed of the drive-side magnet 20. Since the drive current of the motor unit 11 flows at a frequency synchronized with the rotation speed of the drive-side magnet 20, etc., fluctuations in the rotation load also cause fluctuations in the frequency of the drive current, which is also reflected in the envelope of the drive current.

[0138] In the seventh embodiment, when determining whether or not the lock determination condition is satisfied, a frequency analysis is performed on the envelope of the drive current output from the envelope detector of the three-phase inverter circuit 72. Fig. 14 shows an example of the result of the frequency analysis on the envelope of the drive current. Fig. 14 shows a standard analysis result RS and a locked-state analysis result RL. The standard analysis result RS shows the result of the frequency analysis on the envelope of the drive current in the standard state. And the locked-state analysis result RL shows the result of the frequency analysis on the envelope of the drive current in the locked state.

[0139] As described above, the value of the envelope of the driving current varies with the fluctuation of the rotation load when the pole piece 25 etc. is locked. For this reason, as shown in Fig. 14, at a specific frequency fs corresponding to the fluctuation of the rotation load, the peak value of the locked analysis result RL is significantly larger than the value of the standard analysis result RS.

[0140] Therefore, in the fifth embodiment, the occurrence of a lock of the pole piece 25 or the like can be detected by performing a frequency analysis on the envelope of the drive current by the lock determination unit 71.

[0141] In the lock determination control in the fifth embodiment, the lock determination condition is that the value of the envelope of the drive current at a specific frequency fs exceeds a reference value in the result of frequency analysis of the envelope of the drive current. In this case, the reference value is determined based on a standard state, and is determined based on the value of the envelope of the drive current at a specific frequency fs in the result of frequency analysis of the envelope of the drive current in the standard state (i.e., the standard analysis result RS).

[0142] In this case, if the value of the envelope of the drive current at the specific frequency fs exceeds the reference value, it can be determined that a fluctuation in the rotation load on the drive-side magnet 20 occurs, and the pole piece 25 and the like are stuck and in a locked state. If not, it can be determined that power is appropriately transmitted between the drive-side magnet 20 and the pole piece 25, and the drive-side magnet 20 and the pole piece 25 are in a normal state in which they can rotate.

[0143] As described above, according to the power transmission device 1 of the seventh embodiment, even when a frequency analysis is performed on the envelope of the drive current of the three-phase motor 11a, the same effects as those of the above-mentioned embodiments can be obtained from a configuration similar to that of the above-mentioned embodiments.

[0144] In other words, according to the power transmission device 1 of the seventh embodiment, the locking of the pole piece 25 in the driven side mechanism section 35, which is partitioned separately from the drive side mechanism section 10, can be accurately determined based on the fluctuation in the envelope of the drive current.

[0145] Eighth embodiment Next, an eighth embodiment, which is different from the above-mentioned embodiment, will be described with reference to Fig. 15 and Fig. 16. In the eighth embodiment, the method of determining whether the motor unit 11, the pole piece 25, etc. are locked is different from that of the above-mentioned embodiment. The configuration of the other parts, such as the driven side mechanism unit 35, is the same as that of the above-mentioned embodiment, so a repeated description will be omitted.

[0146] 15, in the power transmission device 1 according to the eighth embodiment, a DC motor 11c is adopted as the motor section 11. The DC motor 11c is a DC commutator motor having a commutator and brushes.

[0147] The circuit section 70 according to the eighth embodiment has a lock determination section 71 and a drive current sensor 73b. The battery B and the DC motor 11c are electrically connected to the circuit section 70. The lock determination section 71 is the same as in the above-mentioned embodiments. The drive current sensor 73b according to the eighth embodiment is a sensor for detecting the drive current supplied to the DC motor 11c.

[0148] Next, the lock determination control in the eighth embodiment will be described with reference to Fig. 16. In the power transmission device 1 according to the sixth embodiment, a DC motor 11c having a commutator and brushes is adopted as the motor section 11. Therefore, in the DC motor 11c, in order to keep the rotation direction of the rotor 13 in a predetermined direction, the direction of the current is switched by the commutator and brushes when the rotation phase of the rotor 13 reaches a predetermined phase.

[0149] Therefore, when a frequency analysis is performed on the drive current of the DC motor 11c, as shown in FIG. 16, a peak due to current switching by the commutator and brushes appears in both the standard analysis result RS and the locked analysis result RL.

[0150] Also in the eighth embodiment, when the non-contact coupling part 60 is in a locked state, the fluctuation of the rotational load between the driving side magnet 20 and the pole piece 25 occurs at a certain period due to magnetic interaction, as in the above-mentioned embodiments. Since the period in which the rotational load fluctuates is different from the period related to the current switching of the commutator and the brushes, at the specific frequency fs, the peak of the drive current related to the locked analysis result RL can be clearly distinguished from the value of the drive current related to the standard analysis result RS.

[0151] Therefore, in the eighth embodiment, the lock determination unit 71 performs frequency analysis on the drive current of the DC motor 11c, so that it is possible to detect the occurrence of a lock of the pole piece 25 or the like.

[0152] In the lockup determination control in the eighth embodiment, the lockup determination condition is that the drive current at the specific frequency fs exceeds a reference value in the result of frequency analysis of the drive current of the DC motor 11c. The reference value in this case is determined based on a standard state, and is determined based on the value of the drive current at the specific frequency fs in the result of frequency analysis of the drive current of the DC motor 11c in the standard state (i.e., the standard analysis result RS).

[0153] In this case, if the value of the drive current of the DC motor 11c at the specific frequency fs exceeds the reference value, it can be determined that a fluctuation in the rotation load on the drive-side magnet 20 occurs, and the pole piece 25 and the like are stuck and in a locked state. If not, it can be determined that power is appropriately transmitted between the drive-side magnet 20 and the fixed magnet 40, and the drive-side magnet 20 and the pole piece 25 are in a standard state in which they can rotate.

[0154] As described above, according to the power transmission device 1 of the eighth embodiment, even when a frequency analysis is performed on the drive current of the DC motor 11c, the same effects as those of the above-mentioned embodiments can be obtained from a configuration similar to that of the above-mentioned embodiments.

[0155] In other words, according to the power transmission device 1 of the eighth embodiment, the locking of the pole piece 25 in the driven side mechanism part 35, which is partitioned separately from the drive side mechanism part 10, can be accurately determined based on fluctuations in the drive current of the DC motor 11c.

[0156] Ninth embodiment Next, a ninth embodiment different from the above-mentioned embodiment will be described with reference to Fig. 17 and Fig. 18. In the ninth embodiment, the method of determining whether the pole piece 25 or the like is locked is different from that of the above-mentioned embodiment. The rest of the configuration of the driven side mechanism section 35 and the like is the same as that of the above-mentioned embodiment, so a repeated description will be omitted.

[0157] 17, in the power transmission device 1 according to the ninth embodiment, a three-phase motor 11a is adopted as the motor unit 11 constituting the drive side mechanism unit 10. The circuit unit 70 according to the seventh embodiment has a lock determination unit 71, a three-phase inverter circuit 72, and a determination voltage specification unit 74.

[0158] The lock determination unit 71 is the same as in the above-described embodiment. The three-phase inverter circuit 72 is electrically connected to the battery B and the three-phase motor 11a, as in the above-described embodiment, and converts the DC power of the battery B into three-phase AC power to supply it to the stator coil 12a of each phase of the three-phase motor 11a.

[0159] The three-phase inverter circuit 72 according to the ninth embodiment determines a duty ratio, which is a ratio between an on time and an off time of the motor unit 11, and supplies power to the DC motor 11c based on the determined duty ratio. That is, PWM control is performed on the three-phase motor 11a.

[0160] Specifically, a predetermined triangular wave is compared with the judgment voltage, and the duty ratio of the voltage supplied to the three-phase motor 11a is determined based on the ratio of the period during which the triangular wave is higher than the judgment voltage to the period during which the triangular wave is lower than the judgment voltage. The judgment voltage specifying unit 74 specifies the judgment voltage for determining the duty ratio. For example, when the triangular wave and the judgment voltage are input to the comparator, the judgment voltage specifying unit 74 specifies the value of the judgment voltage input to the comparator.

[0161] Next, the lock determination control in the ninth embodiment will be described with reference to Fig. 18. As described above, the operation of the three-phase motor 11a in the ninth embodiment is controlled by PWM control. Therefore, the higher the duty ratio, the faster the rotation speed of the rotor 13 in the three-phase motor 11a, and the lower the duty ratio, the slower the rotation speed of the rotor 13.

[0162] For this reason, in the ninth embodiment, when the pole piece 25 or the like is fixed and locked, causing a change in the rotational load on the drive-side magnet 20, the duty ratio changes in response to the change in the rotational load. As described above, the duty ratio is determined by comparing the triangular wave with the determination voltage, so the determination voltage changes with the same period as the change in the duty ratio.

[0163] On the other hand, in the standard state, since there is no large fluctuation in the rotation load between the drive-side magnet 20 and the pole piece 25, there is no large fluctuation in the duty ratio and the determination voltage.

[0164] In the lock determination control according to the ninth embodiment, a frequency analysis is performed on the determination voltage. As shown in Fig. 18, in the locked state analysis result RL, a peak of the determination voltage appears at a specific frequency fs corresponding to a fluctuation in the rotation load. On the other hand, in the standard state, there is no large fluctuation in the rotation load, and the drive-side magnet 20 and the pole piece 25 rotate appropriately. For this reason, in the standard analysis result RS, the value of the determination voltage does not fluctuate greatly at the specific frequency fs.

[0165] Therefore, in the ninth embodiment, the lock determination unit 71 performs frequency analysis on the determination voltage related to the PWM control, so that it is possible to detect the occurrence of locking of the pole piece 25 or the like.

[0166] In the lock determination control of the ninth embodiment, the lock determination condition is that the determination voltage at the specific frequency fs exceeds a reference value in the result of frequency analysis of the determination voltage related to the PWM control. In this case, the reference value is determined based on the standard state, and is determined based on the value of the determination voltage at the specific frequency fs in the result of frequency analysis of the determination voltage in the standard state (i.e., the standard analysis result RS).

[0167] In this case, if the value of the judgment voltage at the specific frequency fs exceeds the reference value, it can be determined that a fluctuation in the rotation load on the driving magnet 20 has occurred, and the pole piece 25 etc. has stuck and is in a locked state. If not, it can be determined that power is being properly transmitted between the driving magnet 20 and the pole piece 25, and the driving magnet 20 and the pole piece 25 are in a normal state in which they can rotate.

[0168] As described above, according to the power transmission device 1 of the ninth embodiment, even if a frequency analysis is performed on a judgment voltage related to the PWM control of the motor section 11, the same effects as those of the above-mentioned embodiments can be obtained from a configuration similar to that of the above-mentioned embodiments.

[0169] In other words, according to the power transmission device 1 of the ninth embodiment, the locking of the pole piece 25 in the driven side mechanism section 35, which is partitioned separately from the drive side mechanism section 10, can be accurately determined based on fluctuations in the judgment voltage.

[0170] Tenth embodiment Next, a tenth embodiment, which is different from the above-mentioned embodiment, will be described with reference to Fig. 19 and Fig. 20. In the tenth embodiment, the method of determining whether the pole piece 25 or the like is locked is different from that of the above-mentioned embodiment. The rest of the configuration of the driven side mechanism section 35 and the like is the same as that of the above-mentioned embodiment, so a repeated description will be omitted.

[0171] 19, in the power transmission device 1 according to the tenth embodiment, a three-phase motor 11a is adopted as the motor unit 11 constituting the drive side mechanism unit 10. The circuit unit 70 according to the eighth embodiment has a lock determination unit 71, a three-phase inverter circuit 72, and a drive current sensor 73u.

[0172] The lock determination unit 71 is the same as in the above-described embodiment. The three-phase inverter circuit 72 is electrically connected to the battery B and the three-phase motor 11a, as in the above-described embodiment, and converts the DC power of the battery B into three-phase AC power to supply it to the stator coil 12a of each phase of the three-phase motor 11a.

[0173] The drive current sensor 73u according to the tenth embodiment is a sensor that detects the drive current of the U phase among the U phase, V phase, and W phase for the three-phase motor 11a. The drive current sensor 73b only needs to detect the drive current for any one phase among the drive currents for the three-phase motor 11a.

[0174] Next, the lock determination control in the tenth embodiment will be described with reference to Fig. 20. When the non-contact connecting portion 60 is in a locked state, the driving magnet 20 rotates, but the pole piece 25 is stopped. Therefore, the fluctuation of the rotation load between the driving magnet 20 and the pole piece 25 occurs at a constant cycle due to magnetic interaction, as in the above-mentioned embodiments.

[0175] Since the pole piece 25 is stationary, when the drive-side magnet 20 rotates, there are states where the magnetism acts to attract and where the magnetism acts to repel between the drive-side magnet 20 and the fixed magnet 40. The rotation speed of the drive-side magnet 20 accelerates and decelerates due to the influence of the magnetic attraction and repulsion between the drive-side magnet 20 and the fixed magnet 40. The drive current of the motor unit 11 flows at a frequency synchronized with the rotation speed of the drive-side magnet 20, etc., so the frequency of the drive current also varies with the variation in the rotation speed.

[0176] In the following explanation, the specific frequency when the rotation speed is slowed down due to the influence of the magnetic force between the fixed magnet 40 is referred to as the first specific frequency fsa, and the specific frequency when the rotation speed is increased due to the influence of the magnetic force between the fixed magnet 40 is referred to as the second specific frequency fsb.

[0177] On the other hand, in the standard state, the drive magnet 20 and the pole piece 25 rotate at a constant rotation speed, so the frequency of the drive current is also constant. The frequency corresponding to the constant rotation speed in the standard state is called the standard frequency fc.

[0178] In the lock determination control according to the tenth embodiment, a frequency analysis is performed on the drive current of any one of the phases for the three-phase motor 11a. As shown in Fig. 20, in the standard analysis result RS, a peak of the drive current appears at the standard frequency fc.

[0179] On the other hand, in the locked state analysis result RL, a peak of the drive current appears at a first specific frequency fsa that is lower than the standard frequency fc. The drive current at the first specific frequency fsa indicates the value at the point in time when the rotation speed of the drive-side magnet 20 slows down due to a fluctuation in the rotation load.

[0180] In addition, in the locked state analysis result RL, a peak of the drive current appears at a second specific frequency fsb that is higher than the standard frequency fc. The drive current at the second specific frequency fsb indicates the value at the point in time when the rotation speed of the drive-side magnet 20 increases due to a change in the rotation load.

[0181] As described above, in the standard state, the drive side magnet 20 and the pole piece 25 rotate at a constant rotational speed, so that a peak appears at the standard frequency fc, but no peak appears at the first specific frequency fsa and the second specific frequency fsb.

[0182] Therefore, in the tenth embodiment, by performing a frequency analysis on the driving current of any one phase for the three-phase motor 11a and comparing the values ​​of the first specific frequency fsa and the second specific frequency fsb, it is possible to detect the occurrence of a lock of the pole piece 25 or the like.

[0183] In the lock determination control in the tenth embodiment, the lock determination condition is that the drive current at the first specific frequency fsa and the second specific frequency fsb exceeds a reference value as a result of frequency analysis of the drive current of any one phase of the three-phase motor 11a.

[0184] In this case, the reference values ​​are determined based on the standard state, for example, the reference value for the first specific frequency fsa is determined based on the value of the drive current at the first specific frequency fsa in the standard analysis result RS, and the reference value for the second specific frequency fsb is determined based on the value of the drive current at the second specific frequency fsb in the standard analysis result RS.

[0185] If the value of the drive current at the first specific frequency fsa exceeds the reference value, it can be determined that a fluctuation in the rotation load on the drive-side magnet 20 occurs, and the pole piece 25 and the like are stuck and in a locked state. If not, it can be determined that power is appropriately transmitted between the drive-side magnet 20 and the pole piece 25, and the drive-side magnet 20 and the pole piece 25 are in a normal state in which they can rotate.

[0186] When the value of the driving current exceeds the respective reference values ​​at either the first specific frequency fsa or the second specific frequency fsb, it is determined that a lock of the pole piece 25 or the like has occurred, thereby making it possible to more reliably detect the occurrence of a locked state.

[0187] Incidentally, it may be configured such that, when the value of the drive current at either the first specific frequency fsa or the second specific frequency fsb exceeds the respective reference value, it is determined that a locked state has occurred.

[0188] As described above, according to the power transmission device 1 of the tenth embodiment, even if a frequency analysis is performed on the driving current of any one phase of the three-phase motor 11a, the same effects as those of the above-mentioned embodiments can be obtained from a configuration similar to that of the above-mentioned embodiments.

[0189] That is, according to the power transmission device 1 of the tenth embodiment, the locking of the pole piece 25 in the driven side mechanism section 35, which is partitioned separately from the drive side mechanism section 10, can be accurately determined based on the fluctuation of the drive current of any one phase of the three-phase motor 11a.

[0190] Eleventh embodiment Next, an eleventh embodiment, which is different from the above-mentioned embodiment, will be described with reference to Fig. 21 and Fig. 22. In the eleventh embodiment, the method of determining whether the pole piece 25, etc. is locked is different from that of the above-mentioned embodiment. The rest of the configuration of the driven side mechanism section 35, etc. is the same as that of the above-mentioned embodiment, so a repeated description will be omitted.

[0191] 21, in the power transmission device 1 according to the 11th embodiment, a three-phase motor 11a is used as the motor unit 11 constituting the drive-side mechanism unit 10. The circuit unit 70 according to the 11th embodiment has a lock determination unit 71, a three-phase inverter circuit 72, and a line voltage sensor 73c.

[0192] The lock determination unit 71 is the same as in the above-described embodiment. The three-phase inverter circuit 72 is electrically connected to the battery B and the three-phase motor 11a, as in the above-described embodiment, and converts the DC power of the battery B into three-phase AC power to supply it to the stator coil 12a of each phase of the three-phase motor 11a.

[0193] The line voltage sensor 73c is a sensor that detects the value of a voltage between any two of the three phases for the three-phase motor 11a. For example, the line voltage sensor 73c detects the value of a line voltage between the U phase and the V phase of the U phase, V phase, and W phase for the three-phase motor 11a.

[0194] Next, the lock determination control in the eleventh embodiment will be described with reference to Fig. 22. As described above, in the locked state, the fluctuation of the rotation load between the driving side magnet 20 and the pole piece 25 occurs at a constant period due to magnetic interaction, similar to the above-mentioned embodiments.

[0195] Since the pole piece 25 is stationary, when the drive-side magnet 20 rotates, there are two states between the drive-side magnet 20 and the fixed magnet 40: one in which the magnetism acts to attract and the other in which the magnetism acts to repel. As a result, the rotation speed of the drive-side magnet 20 accelerates and decelerates due to the influence of the magnetic attraction and repulsion between the drive-side magnet 20 and the fixed magnet 40. The drive current of the motor unit 11 flows at a frequency synchronized with the rotation speed of the drive-side magnet 20, etc., so the line voltage of any two phases in the three-phase motor 11a also fluctuates with the fluctuation in the rotation speed.

[0196] In the lock determination control according to the eleventh embodiment, a frequency analysis is performed on the line voltages of any two phases of the three-phase motor 11a. As shown in Fig. 22, in the standard analysis result RS, a peak of the line voltage appears at the standard frequency fc.

[0197] On the other hand, in the locked state analysis result RL, the drive current peaks appear at the first specific frequency fsa and the second specific frequency fsb. The line voltage at the first specific frequency fsa indicates the value at the point in time when the rotation speed of the drive-side magnet 20 slows down due to fluctuations in the rotation load. The line voltage at the second specific frequency fsb indicates the value at the point in time when the rotation speed of the drive-side magnet 20 speeds up due to fluctuations in the rotation load.

[0198] As described above, in the standard state, the drive side magnet 20 and the pole piece 25 rotate at a constant rotational speed, so that a peak appears at the standard frequency fc, but no peak appears at the first specific frequency fsa and the second specific frequency fsb.

[0199] Therefore, in the eleventh embodiment, by performing frequency analysis on the line voltages of any two phases of the three-phase motor 11a and comparing the values ​​of the first specific frequency fsa and the second specific frequency fsb, it is possible to detect the occurrence of a lock of the pole piece 25, etc.

[0200] In the lock determination control in the eleventh embodiment, the lock determination condition is that the line voltages at the first specific frequency fsa and the second specific frequency fsb exceed reference values ​​as a result of frequency analysis of the line voltages of any two phases of the three-phase motor 11a.

[0201] In this case, the reference values ​​are determined based on the standard state, for example, the reference value for the first specific frequency fsa is determined based on the value of the line voltage at the first specific frequency fsa in the standard analysis result RS, and the reference value for the second specific frequency fsb is determined based on the value of the line voltage at the second specific frequency fsb in the standard analysis result RS. If the value of the line voltage at the first specific frequency fsa exceeds the reference value, it can be determined that a fluctuation in the rotation load of the driving magnet 20 occurs, and the pole piece 25 and the like are in a locked state. If not, it can be determined that the driving magnet 20 and the pole piece 25 are in a standard state in which they can rotate.

[0202] When the value of the line voltage exceeds the respective reference value at either the first specific frequency fsa or the second specific frequency fsb, it is determined that a lock of the pole piece 25 or the like has occurred, thereby making it possible to more reliably detect the occurrence of a locked state.

[0203] As described above, according to the power transmission device 1 of the eleventh embodiment, even when a frequency analysis is performed on the line voltage of the three-phase motor 11a, the same effects as those of the above-mentioned embodiments can be obtained from a configuration similar to that of the above-mentioned embodiments.

[0204] In other words, according to the power transmission device 1 of the eleventh embodiment, the locking of the pole piece 25 in the driven side mechanism section 35, which is partitioned separately from the drive side mechanism section 10, can be accurately determined based on fluctuations in the line voltage of the three-phase motor 11a.

[0205] Twelfth embodiment Next, a twelfth embodiment, which is different from the above-mentioned embodiment, will be described with reference to Fig. 23 and Fig. 24. In the twelfth embodiment, the method of determining whether the pole piece 25, etc. is locked is different from that of the above-mentioned embodiment. The rest of the configuration of the driven side mechanism section 35, etc. is the same as in the above-mentioned embodiment, so a repeated description will be omitted.

[0206] In the power transmission device 1 according to the twelfth embodiment, the circuit unit 70 has a lock determination unit 71 and an acceleration sensor 73d. As shown in Fig. 23, the acceleration sensor 73d is disposed in the motor case 15 of the drive side mechanism unit 10, and detects a change in acceleration occurring in the drive side mechanism unit 10. Therefore, in the power transmission device 1 according to the twelfth embodiment, the acceleration sensor 73d can detect vibrations caused by the operation of the motor unit 11 of the drive side mechanism unit 10.

[0207] Next, the lock determination control in the twelfth embodiment will be described with reference to Fig. 24. As described above, in the normal state, there is almost no variation in the rotation load between the drive-side magnet 20 and the pole piece 25, and the drive-side magnet 20 and the pole piece 25 rotate together. In other words, the drive-side mechanism 10 vibrates at a constant cycle due to the drive-side magnet 20 and the pole piece 25 rotating together.

[0208] On the other hand, in the locked state, the pole piece 25 is stopped, and therefore when the drive-side magnet 20 rotates, the rotation load fluctuates due to magnetic interaction with the fixed magnet 40. The fluctuation in the rotation load changes the rotation speed of the drive-side magnet 20 and the shaft 14, and therefore vibrations due to the fluctuation in the rotation load are generated in the drive-side mechanism 10 including the motor unit 11.

[0209] The period of vibration occurring in the locked state differs from the period of vibration occurring in the standard state due to the influence of magnetism between the drive-side magnet 20 and the fixed magnet 40. As a result, by analyzing the period of vibration occurring in the drive-side mechanism section 10 using the acceleration sensor 73d, it can be determined whether or not the pole piece 25, etc., is locked.

[0210] In the lock determination control according to the twelfth embodiment, a frequency analysis is performed on the detection signal of the acceleration sensor 73d. As shown in Fig. 24, in the standard analysis result RS, an acceleration peak appears at a standard frequency fc. The standard frequency fc corresponds to the generation period of vibration caused by the rotation of the driving side magnet 20 and the pole piece 25 in the standard state.

[0211] On the other hand, in the locked state analysis result RL, an acceleration peak appears at a specific frequency fs. The acceleration peak at the specific frequency fs is caused by vibration of the drive side mechanism portion 10 due to fluctuations in the rotation load.

[0212] As described above, in the standard state, the drive magnet 20 and the pole piece 25 rotate at a constant rotational speed, so that a peak appears at the standard frequency fc, and no acceleration peak appears at the specific frequency fs.

[0213] Therefore, in the twelfth embodiment, by performing frequency analysis on the detection signal of the acceleration sensor 73d and comparing the value of the specific frequency fs, it is possible to detect the occurrence of locking of the pole piece 25 or the like.

[0214] In the lockup determination control in the twelfth embodiment, the lockup determination condition is that the acceleration value at the specific frequency fs exceeds a reference value in the result of frequency analysis of the detection signal of the acceleration sensor 73d. In this case, the reference value is determined based on a standard state, and is determined based on the acceleration value at the specific frequency fs in the standard analysis result RS, for example.

[0215] If the acceleration value at the specific frequency fs exceeds the reference value, it can be determined that a fluctuation in the rotation load on the driving magnet 20 occurs, and the pole piece 25 and the like are in a locked state. If not, it can be determined that the driving magnet 20 and the pole piece 25 are in a standard state in which they can rotate.

[0216] As described above, according to the power transmission device 1 of the 12th embodiment, even if a frequency analysis is performed on the acceleration detected by the acceleration sensor 73d, the same effects as those of the above-mentioned embodiments can be obtained from a configuration similar to that of the above-mentioned embodiments.

[0217] That is, according to the power transmission device 1 of the twelfth embodiment, the locking of the pole piece 25 in the driven side mechanism part 35, which is partitioned separately from the driving side mechanism part 10, can be accurately determined based on the fluctuation in acceleration detected by the acceleration sensor 73d.

[0218] Thirteenth embodiment In the above-described first embodiment and the like, the stator 12 and rotor 13 of the motor unit 11 are disposed inside the drive-side magnet 20 of the magnetic gear 60b. As a result, the stator 12, rotor 13, and drive-side magnet 20 are aligned in the radial direction, and an induced voltage is generated in the motor unit 11 by the drive-side magnet 20, which becomes a rotational resistance.

[0219] In view of the above, the present embodiment aims to suppress the generation of rotational resistance in the motor portion 11 of the first expansion valve 113 due to the magnetic gear 60b of the power transmission device 1.

[0220] 25 and 26, the motor unit 11 of this embodiment is a three-phase motor 11a. A cylindrical rotor 13 is disposed radially outside the stator 12.

[0221] The number of slots Ns of the stator 12 is 6. Therefore, there are two slots for each of the U phase, V phase, and W phase. The six slots of the stator 12 are arranged in the circumferential direction in the order of U phase slot 12U, V phase slot 12V, W phase slot 12W, U phase slot 12U, V phase slot 12V, and W phase slot 12W. The six slots 12U, 12V, 12W, 12U, 12V, and 12W of the stator 12 are arranged evenly in the circumferential direction. The six slots 12U, 12V, 12W, 12U, 12V, and 12W of the stator 12 are arranged every 60 degrees in the circumferential direction.

[0222] Therefore, among the six slots 12U, 12V, 12W, 12U, 12V, and 12W of the stator 12, pairs of slots of the same phase are arranged at 180-degree intervals in the circumferential direction. In other words, among the six slots 12U, 12V, 12W, 12U, 12V, and 12W of the stator 12, pairs of slots of the same phase are arranged in positions facing each other.

[0223] The winding direction of the stator coil 12a of the stator 12 is the same for all slots.

[0224] The drive-side magnet 20 is disposed coaxially with the rotor 13 on the radially outer side of the rotor 13 .

[0225] The number of poles Pin of the drive-side magnet 20 is 2. Therefore, the number of pole pairs of the drive-side magnet 20 is 1. The N poles 20n and S poles 20s of the drive-side magnet 20 are alternately and evenly spaced in the circumferential direction. The N poles 20n and S poles 20s of the drive-side magnet 20 are spaced 180 degrees apart in the circumferential direction.

[0226] In two slots of each phase of the three-phase motor 11a, the positional relationship between the N pole 40n and the S pole 40s of the drive-side magnet 20 is opposite to each other, and the magnetic flux of the drive-side magnet 20 has an opposite phase.

[0227] 27, in two slots of one phase of the three-phase motor 11a, the induced voltages by the drive-side magnet 20 are in opposite phases and cancel each other out, so that the sum of the induced voltages in one phase of the three-phase motor 11a becomes 0. Similarly, the sum of the induced voltages in the other two phases also becomes 0.

[0228] Therefore, in the slots of each phase, the induced voltages by the drive-side magnets 20 are offset, so that the rotational resistance in the motor section 11 can be reduced.

[0229] In this embodiment, the drive-side magnet 20 is configured so that the induced voltages generated in the stator coil 12a by the drive-side magnet 20 are cancelled out in each phase. In other words, the drive-side magnet 20 is configured so that the sum of the induced voltages generated in the stator coil 12a by the drive-side magnet 20 in each phase becomes zero. This allows the rotational resistance in the motor unit 11 to be reduced.

[0230] Fourteenth embodiment In the above embodiment, the number of slots in each phase of the three-phase motor 11a is set to 2, and the number of pole pairs in the drive-side magnet 20 is set to 1, so that the sum of the induced voltages in each phase of the three-phase motor 11a is zero. In this embodiment, as shown in Fig. 28, the number of pole pairs in the drive-side magnet 20 is different from a multiple of the number of slots in one phase. In other words, the number of pole pairs in the drive-side magnet 20 is different from an integer multiple of the number of slots in one phase.

[0231] 28 and 29, the motor unit 11 is a three-phase motor 11a. The cylindrical rotor 13 is disposed radially outside the stator 12.

[0232] The number of slots Ns of the stator 12 is 9. Therefore, there are three slots for each of the U phase, V phase, and W phase. The nine slots of the stator 12 are arranged in the circumferential direction in the following order: U phase slots 12U, V phase slots 12V, W phase slots 12W, U phase slots 12U, V phase slots 12V, W phase slots 12W, U phase slots 12U, V phase slots 12V, and W phase slots 12W.

[0233] The nine slots 12U, 12V, 12W, 12U, 12V, 12W, 12U, 12V, and 12W of the stator 12 are evenly arranged in the circumferential direction. The nine slots 12U, 12V, 12W, 12U, 12V, 12W, 12U, 12V, and 12W of the stator 12 are arranged every 40 degrees in the circumferential direction.

[0234] Therefore, of the nine slots 12U, 12V, 12W, 12U, 12V, 12W, 12U, 12V, 12W, 12U, 12V, 12W of the stator 12, three slots of the same phase are arranged every 120 degrees in the circumferential direction.

[0235] The winding direction of the stator coil 12a of the stator 12 is the same for all slots.

[0236] The drive-side magnet 20 is disposed coaxially with the rotor 13, radially outside the rotor 13. The number of poles Pin of the drive-side magnet 20 is 4. Therefore, the number of pole pairs of the drive-side magnet 20 is 2. The N poles 20n and S poles 20s of the drive-side magnet 20 are alternately and evenly arranged in the circumferential direction. The N poles 20n and S poles 20s of the drive-side magnet 20 are arranged at 90-degree intervals in the circumferential direction.

[0237] In this configuration, when a current flows through the stator coil 12a and the rotor 13 rotates, the phases of the induced voltages by the drive-side magnet 20 are shifted by 120 degrees in the three slots of each phase of the three-phase motor 11a, as shown in Fig. 30, so the sum of the induced voltages in each phase of the three-phase motor 11a becomes approximately 0. Similarly, the sum of the induced voltages in the other two phases also becomes approximately 0.

[0238] Therefore, in the slots of each phase, the induced voltages by the drive-side magnets 20 are almost cancelled out, so that the rotational resistance in the motor section 11 can be reduced.

[0239] In this embodiment, the winding direction of the stator coil 12a of the stator 12 is the same for all slots, and the number of pole pairs of the drive-side magnet 20 is different from a multiple of the number of slots for each phase.

[0240] As a result, the induced voltages by the drive-side magnets 20 are almost cancelled out in the slots of each phase, so that the rotational resistance in the motor section 11 can be reduced.

[0241] Fifteenth embodiment In the thirteenth embodiment, the winding direction of the stator coil 12a of the stator 12 is the same for all slots, but in this embodiment, the number of slots in which the stator coil 12a is wound right-handed is the same as the number of slots in which the stator coil 12a is wound left-handed. The number of pole pairs of the drive magnet 20 is an odd multiple of half the number of single-phase slots.

[0242] 31 and 32, the motor unit 11 of this embodiment is a three-phase motor 11a. A cylindrical rotor 13 is disposed radially outside the stator 12.

[0243] The number of slots Ns of the stator 12 is six. Therefore, the stator 12 has three right-handed slots and three left-handed slots. There are also two slots for each of the U, V, and W phases. The six slots of the stator 12 are arranged in the circumferential direction in the following order: right-handed slots 12UR of the U phase, left-handed slots 12VL of the V phase, right-handed slots 12WR of the W phase, left-handed slots 12UL of the U phase, right-handed slots 12VR of the V phase, and left-handed slots 12WL of the W phase.

[0244] The six slots 12UR, 12VL, 12WR, 12UL, 12VR, and 12WL of the stator 12 are evenly spaced in the circumferential direction. The six slots 12UR, 12VL, 12WR, 12UL, 12VR, and 12WL of the stator 12 are spaced every 60 degrees in the circumferential direction.

[0245] Therefore, among the six slots 12UR, 12VL, 12WR, 12UL, 12VR, and 12WL of the stator 12, pairs of slots of the same phase are arranged at 180-degree intervals in the circumferential direction. In other words, among the six slots 12UR, 12VL, 12WR, 12UL, 12VR, and 12WL of the stator 12, pairs of slots of the same phase are arranged in positions facing each other.

[0246] Of the six slots 12UR, 12VL, 12WR, 12UL, 12VR, and 12WL of the stator 12, the winding direction of the stator coil 12a in one slot of a pair of slots of the same phase is right-handed, and the winding direction of the stator coil 12a in the other slot is left-handed. Therefore, in a pair of slots of the same phase, there are the same number of right-handed and left-handed stator coils 12a.

[0247] Of the six slots 12UR, 12VL, 12WR, 12UL, 12VR, and 12WL of the stator 12, slots in which the stator coil 12a is wound right-handed and slots in which the stator coil 12a is wound left-handed are arranged alternately.

[0248] Therefore, among the six slots of the stator 12, a pair of opposing slots have the stator coils 12a wound in opposite directions.

[0249] The driving side magnet 20 is disposed coaxially with the rotor 13 on the radially outer side of the rotor 13 .

[0250] The number of poles Pin of the drive-side magnet 20 is 8. Therefore, the number of pole pairs of the drive-side magnet 20 is 4. The N poles 20n and S poles 20s of the drive-side magnet 20 are alternately and evenly spaced in the circumferential direction. The N poles 20n and S poles 20s of the drive-side magnet 20 are spaced at 45 degrees from each other in the circumferential direction.

[0251] In the two slots of each phase of the three-phase motor 11a, the positional relationship between the N pole 40n and the S pole 40s of the drive-side magnet 20 is the same, but since the winding directions of the stator coil 12a are opposite to each other, the magnetic flux of the drive-side magnet 20 has opposite phases.

[0252] 27, in two slots of one phase of the three-phase motor 11a, the induced voltages by the drive-side magnet 20 are in opposite phases and cancel each other out, so that the sum of the induced voltages in one phase of the three-phase motor 11a becomes 0. Similarly, the sum of the induced voltages in the other two phases also becomes 0.

[0253] Therefore, in the slots of each phase, the induced voltages by the drive-side magnets 20 are offset, so that the rotational resistance in the motor section 11 can be reduced.

[0254] In this embodiment, the slots of the stator 12 are arranged in such a way that the number of right-handed and left-handed windings of the stator coil 12a in each phase is equal, and the number of pole pairs of the drive side magnet 20 is an odd multiple of half the number of slots in each phase.

[0255] As a result, the induced voltages by the drive-side magnets 20 are almost cancelled out in the slots of each phase, so that the rotational resistance in the motor section 11 can be reduced.

[0256] Sixteenth embodiment In the fifteenth embodiment, the motor unit 11 is a three-phase motor 11a, but in this embodiment, as shown in FIG. 33, the motor unit 11 is a stepping motor 11b.

[0257] The cylindrical rotor 13 is disposed radially outside the stator 12 .

[0258] The number of slots Ns of the stator 12 is 8. The eight slots of the stator 12 are evenly spaced in the circumferential direction. The six slots of the stator 12 are spaced every 45 degrees in the circumferential direction.

[0259] Of the eight slots in the stator 12, the number of slots 12R in which the stator coil 12a is wound right-handed is the same as the number of slots 12L in which the stator coil 12a is wound left-handed. There are four slots 12R in which the stator coil 12a is wound right-handed, and four slots 12L in which the stator coil 12a is wound left-handed.

[0260] Of the eight slots 12R, 12L of the stator 12, the four slots 12R in which the stator coil 12a is wound right-handed are arranged consecutively in the circumferential direction, and the four slots 12L in which the stator coil 12a is wound left-handed are also arranged consecutively in the circumferential direction.

[0261] Therefore, among the eight slots 12R, 12L of the stator 12, a pair of opposing slots have the stator coils 12a wound in opposite directions.

[0262] The driving side magnet 20 is disposed coaxially with the rotor 13 on the radially outer side of the rotor 13 .

[0263] The number of poles Pin of the drive-side magnet 20 is 8. Therefore, the number of pole pairs of the drive-side magnet 20 is 4. The N poles 20n and S poles 20s of the drive-side magnet 20 are alternately and evenly spaced in the circumferential direction. The N poles 20n and S poles 20s of the drive-side magnet 20 are spaced at 45 degrees from each other in the circumferential direction.

[0264] Of the eight slots 12R, 12L of the stator 12, in a pair of opposing slots, the positional relationship with the N pole 40n and S pole 40s of the drive-side magnet 20 is the same, but since the winding directions of the stator coil 12a are opposite to each other, the magnetic flux of the drive-side magnet 20 has opposite phases.

[0265] Therefore, as in the above-mentioned Figure 27, in a pair of opposing slots, the induced voltages by the drive side magnet 20 are in opposite phase and cancel each other out, so that the sum of the induced voltages in a pair of opposing slots becomes zero.

[0266] Therefore, in a pair of opposing slots, the induced voltages by the drive-side magnets 20 are offset, so that the rotational resistance in the motor section 11 can be reduced.

[0267] Seventeenth embodiment In the above embodiment, the rotor 13, the stator 12, and the drive-side magnet 20 are aligned in the radial direction of the rotor 13, but in this embodiment, as shown in Fig. 34, the rotor 13, the stator 12, and the drive-side magnet 20 are aligned in the axial direction of the rotor 13. That is, in this embodiment, the motor unit 11 is an axial gear motor 11d.

[0268] In the axial gear motor 11d, the arrangement direction of the stator 12 and the drive-side magnet 20 is the same as the arrangement direction of the rotor 13 and the stator 12, so the direction of the magnetic flux due to the stator 12 and the drive-side magnet 20 is the same as the direction of the magnetic flux due to the rotor 13 and the stator 12. Therefore, an induced voltage is generated in the motor section 11 by the drive-side magnet 20, which becomes a rotational resistance.

[0269] Therefore, in this embodiment as well, by making the relationship between the number of slots Ns of the stator 12 and the number of poles Pin of the drive side magnet 20 the same as in the above 13th to 17th embodiments, the induced voltage by the drive side magnet 20 is canceled out, thereby reducing the rotational resistance in the motor section 11.

[0270] (18th embodiment) In this embodiment, as shown in FIG. 35, the circuit section 70 is provided with an angle sensor 77 for detecting a rotation angle.

[0271] The angle sensor 77 detects the magnetic flux of the drive-side magnet 20 to detect the rotation angle of the drive-side magnet 20 , that is, the rotation angle of the shaft 14 .

[0272] The detection signal of the angle sensor 77 is input to the circuit section 70. The circuit section 70 controls the drive current for driving the three-phase motor 11a based on the detection signal of the angle sensor 77.

[0273] The angle sensor 77 is fixed to the circuit unit 70 above the driving-side magnet 20. The angle sensor 77 is disposed radially outward of the radially inner end of the driving-side magnet 20 and radially inward of the radial center of the pole piece 25 in the radial direction of the rotor 13.

[0274] Since the outer peripheral surface of the drive-side magnet 20 is magnetized, the closer the position of the angle sensor 77 is to the outer peripheral surface of the drive-side magnet 20, the better the magnetic flux of the drive-side magnet 20 can be detected.

[0275] It is preferable that the upper end of the driving-side magnet 20 is located higher than the upper ends of the pole piece 25 and the fixed magnet 40. This brings the upper end of the driving-side magnet 20 closer to the angle sensor 77, and the amount of magnetic flux of the driving-side magnet 20 in the vicinity of the angle sensor 77 increases, so that the magnetic flux of the driving-side magnet 20 can be detected well.

[0276] The number of poles Pin of the drive-side magnet 20 is 2. As a result, when the drive-side magnet 20 rotates once, the waveform of the magnetic flux detected by the angle sensor 77 is generated for one period, so that the rotation angle of the shaft 14 can be detected by the angle sensor 77 with high accuracy.

[0277] A cylindrical pressure vessel 58 is disposed between the fixed magnet 40 and the cylindrical main body portion 50b of the main body portion 50.

[0278] A reinforcing plate 59 is provided between the circuit section 70 and the motor case 15. The reinforcing plate 59 is a member that reinforces the bearing portion of the shaft 14. The reinforcing plate 59 is fixed to the circuit section 70 and the motor case 15. As shown in Figure 36, the reinforcing plate 59 and the circuit section 70 are formed with bearing holes 59a, 70a into which the bearing portion of the shaft 14 is inserted.

[0279] The pressure vessel 58 and the reinforcing plate 59 are formed of a non-magnetic material, which makes it possible to prevent the pressure vessel 58 and the reinforcing plate 59 from adversely affecting the detection of magnetic flux by the angle sensor 77.

[0280] Nineteenth embodiment In the above-described 18th embodiment, the reinforcing plate 59 is formed of a non-magnetic material, whereas in the present embodiment, the reinforcing plate 59 is formed of a magnetic material, and as shown in FIG. 37, a portion of the reinforcing plate 59 near the angle sensor 77 is cut out to form a cutout portion 59b.

[0281] This makes it possible to prevent the reinforcing plate 59 from adversely affecting the detection of magnetic flux by the angle sensor 77 even if the reinforcing plate 59 is made of a magnetic material.

[0282] (Twentieth embodiment) In the nineteenth embodiment, the reinforcing plate 59 is fixed to the motor case 15, but in this embodiment, as shown in FIG.

[0283] The reinforcing plate 59 is fastened to the sealing plate 51 with a bolt 80. Specifically, a bolt fixing portion 51f is formed on the sealing upper surface portion 51a of the sealing plate 51. The bolt fixing portion 51f has a cylindrical shape that protrudes toward the reinforcing plate 59. A female screw hole 51g is formed in the bolt fixing portion 51f. A thread groove that screws into the bolt 80 is formed in the female screw hole 51g.

[0284] Fig. 39 is a plan view of the reinforcing plate 59 as viewed from the axial direction of the shaft 14. As shown in Fig. 39, the reinforcing plate 59 is formed with a bolt hole 59c through which the bolt 80 passes. Fig. 40 is a plan view of the circuit board 701 of the circuit section 70 as viewed from the axial direction of the shaft 14. As shown in Fig. 40, the circuit board 701 is formed with a through hole 701a through which the bolt fixing portion 51f passes.

[0285] A large number of bolt fixing portions 51f, bolt holes 59c and through holes 701a are formed. In this example, three bolt fixing portions 51f, three bolt holes 59c and three through holes 701a are formed.

[0286] 38, an end face of bolt fixing portion 51f is in contact with reinforcing plate 59. An end face of bolt fixing portion 51f is in contact with reinforcing plate 59. A circuit board 701 is fixed to reinforcing plate 59. For example, circuit board 701 is a glass epoxy board. A glass epoxy board is a base material in which glass fiber cloth is layered and impregnated with epoxy resin.

[0287] The main body 50, the sealing plate 51, and the reinforcing plate 59 are made of a metal that is both a conductor and a magnetic material (for example, an iron-based metal or stainless steel). Therefore, the sealing plate 51 and the reinforcing plate 59 are electrically connected to the main body 50 and to the ground (GND).

[0288] The circuit board 701 and the reinforcing plate 59 have the same planar shape, and in this example, are rectangular and larger than the cylindrical main body portion 50b. The portion of the main body portion 50 below the cylindrical main body portion 50b is the rectangular main body portion 50c, which has a rectangular outer shape.

[0289] The motor case 15 has an upper case 15b and a lower case 15c. The upper case 15b and the lower case 15c are formed of a conductive material (for example, a resin mixed with iron powder).

[0290] Upper case 15b is formed in a square tubular shape with a lid. Lower case 15c has an upper portion (the portion on the upper case 15b side) that has a square tubular shape and a lower portion (the portion on the main body square column portion 50c side) that has a cylindrical shape.

[0291] The motor case 15 (in this example, the upper case 15b) is fitted into the main body 50 so as to cover the sealing plate 51 and the reinforcing plate 59 from the radially outer side. As a result, the gap between the sealing plate 51 and the reinforcing plate 59 is blocked by the motor case 15.

[0292] The circuit section 70 has a plurality of circuit elements. Some of the plurality of circuit elements are circuit elements that generate radiation noise. In this example, the circuit element that generates radiation noise is a FET microcomputer 702. The FET microcomputer 702 converts the DC power of the battery into AC power by switching and outputs the AC power. In addition to the FET microcomputer 702, the circuit elements that generate radiation noise include electronic components including coils and IC chips.

[0293] The FET microcomputer 702 and other circuit elements 703 are joined by soldering to the circuit board 701. The FET microcomputer 702 is disposed at a position where it overlaps with the reinforcing plate 59 and the sealing plate 51 when viewed from the axial direction of the shaft 14.

[0294] The FET microcomputer 702 is a QFN (Quad Flat Non-leaded) type element. A QFN type element is an element without leads. Therefore, as shown in FIG. 41, a terminal 702a of the FET microcomputer 702 is joined by solder 704 sandwiched between the terminal 702a and a copper foil pattern 701b of the circuit board 701 without being inserted into the circuit board 701.

[0295] The switching of the FET microcomputer 702 causes radiation noise, but the sealing plate 51, the reinforcing plate 59 and the motor case 15 can block the radiation noise from the FET microcomputer 702.

[0296] The sealing plate 51 and the reinforcing plate 59 are electrically connected to the main body 50 and the ground (GND), thereby making it possible to improve the effect of blocking radiated noise.

[0297] Since the main body 50, the sealing plate 51 and the reinforcing plate 59 are made of a magnetic material, the effect of blocking low-frequency components of radiated noise can be improved.

[0298] The circuit board 701 is fixed to the reinforcing plate 59, which is fixed to the sealing plate 51, which is fixed to the main body 50. In other words, the circuit board 701 is fixed to the main body 50, which has high strength, via the reinforcing plate 59 and the sealing plate 51.

[0299] As a result, bolt fixing portion 51f, which is the fixing portion between circuit board 701 and reinforcing plate 59, serves as a fulcrum, and circuit board 701 deforms as shown in Fig. 42. That is, as shown by the two-dot chain line in Fig. 42, circuit board 701 deforms on the outer side of bolt fixing portion 51f, but deformation of circuit board 701 is suppressed on the inner side of bolt fixing portion 51f. Therefore, stress in the soldered portion on circuit board 701 is reduced.

[0300] When viewed in the axial direction of shaft 14, FET microcomputer 702 is disposed on the shaft 14 side of imaginary circumscribing circle C1 of through-hole 701a (in other words, the portion where circuit board 701 and reinforcing plate 59 are fixed). Specifically, it is disposed in first range A1 hatched in Fig. 40. This effectively reduces stress acting on the soldered portion of circuit board 701 and FET microcomputer 702 (i.e., solder 704).

[0301] More preferably, FET microcomputer 702 is disposed between through-holes 701a when viewed in the axial direction of shaft 14. Specifically, FET microcomputer 702 is disposed in second range A2 shaded in Fig. 40. This further effectively reduces the stress acting on the soldered portions of circuit board 701 and FET microcomputer 702.

[0302] In this embodiment, the FET microcomputer 702 is disposed at a position on the circuit board 701 where it overlaps with the sealing plate 51 in the axial direction of the driving-side magnet 20, and the sealing plate 51 is made of a conductor. This allows the sealing plate 51 to block radiation noise from the FET microcomputer 702 in the axial direction of the driving-side magnet 20.

[0303] In this embodiment, the reinforcing plate 59 is made of a conductor, and the FET microcomputer 702 is disposed at a position where it overlaps with the reinforcing plate 59 in the axial direction of the drive-side magnet 20. This allows the reinforcing plate 59 to block radiation noise from the FET microcomputer 702 in the axial direction of the drive-side magnet 20.

[0304] In this embodiment, the FET microcomputer 702 is disposed so as to face the sealing plate 51 side with respect to the circuit board 701. The case 15 is formed of a conductor, and closes the gap between the sealing plate 51 and the circuit board 701 from the radial outside of the drive-side magnet 20. This allows the case 15 to block radiation noise from the FET microcomputer 702 in the radial direction of the drive-side magnet 20.

[0305] In this embodiment, the main body 50 is made of a conductor, the sealing plate 51 is fixed to the main body 50, and the bolt fixing portion 51f of the sealing plate 51 electrically connects the sealing plate 51 to the reinforcing plate 59. As a result, the sealing plate 51 and the reinforcing plate 59 are electrically connected to the main body 50 and to the ground (GND), thereby improving the effect of blocking radiation noise.

[0306] In this embodiment, the circuit board 701 is fixed to the reinforcing plate 59, and the sealing plate 51 has a fixing portion 51f to which the reinforcing plate 59 is fixed. This suppresses deformation of the circuit board 701, thereby reducing stress on the soldered portions of the circuit board 701.

[0307] In this embodiment, fixed portions 51f are provided in at least three places, and FET microcomputer 702 is disposed in a first range A1 on circuit board 701. First range A1 is the range inside an imaginary circumscribing circle that circumscribes all of fixed portions 51f. This effectively reduces stress acting on the soldered portions (i.e., solder 704) of circuit board 701 and FET microcomputer 702.

[0308] (21st embodiment) In the twentieth embodiment, three bolt fixing portions 51f are formed, but in this embodiment, two bolt fixing portions 51f are formed. The bolt fixing portions 51f are formed at 180 degree intervals in the circumferential direction of the shaft 14.

[0309] Therefore, as shown in FIG. 43, the reinforcing plate 59 has two bolt holes 59c through which the bolts 80 pass, and as shown in FIG. 44, the circuit board 701 has two through holes 701a through which the bolt fixing portions 51f pass.

[0310] FET microcomputer 702 is disposed between through-holes 701a when viewed in the axial direction of shaft 14. Specifically, it is disposed in second range A2 shaded in Fig. 44. This effectively suppresses stress acting on the soldered portions of circuit board 701 and FET microcomputer 702.

[0311] In this embodiment, fixing portions 51f are provided in two places, and FET microcomputer 702 is disposed in second area A2 on circuit board 701. Second area A2 is area A2 between fixing portions 51f. This effectively suppresses stress acting on the soldered portions of circuit board 701 and FET microcomputer 702.

[0312] (Twenty-second embodiment) If the stator 12 and rotor 13 of the motor unit 11 are arranged inside the driving side magnet 20 as in the first embodiment described above, the magnetic flux of the motor unit 11 and the magnetic flux of the driving side magnet 20 may interfere with each other, resulting in poor flow of magnetic flux in the magnetic gear 60b.

[0313] In consideration of this point, the present embodiment has a configuration for reducing magnetic interference between the magnetic flux of the driving-side magnet 20 and the magnetic flux of the motor section 11.

[0314] As shown in Fig. 48, the interposition member 21 has a motor back yoke 21a and a rotor cup 21b. The motor back yoke 21a is cylindrical, and is disposed between the rotor 13 and the driving-side magnet 20, coaxially with the rotor 13 and the driving-side magnet 20. The rotor cup 21b closes the motor back yoke 21a from one axial end side of the driving-side magnet 20 (the lower side in Fig. 48). The motor back yoke 21a and the rotor cup 21b are formed of a magnetic material.

[0315] For convenience of illustration, the motor case 15, the sealing plate 51, the back yoke 56, etc. are omitted in FIG.

[0316] In the axial direction of the drive-side magnet 20, i.e., the vertical direction in Figure 48, the lower end position Bmg of the drive-side magnet 20, pole piece 25 and fixed magnet 40 is lower than the lower end position Bmt of the stator 12, rotor 13 and motor section back yoke 21a.

[0317] As a result, as shown in FIG. 49, the magnetic flux Mmg of the drive-side magnet flows so as to avoid the magnetic flux Mmt of the motor section 11 below, thereby reducing magnetic interference and improving performance.

[0318] In the axial direction of the drive-side magnet 20, i.e., the vertical direction in Figure 48, the upper end position Umg of the drive-side magnet 20, pole piece 25 and fixed magnet 40 is lower than the upper end position Umt of the stator 12, rotor 13 and motor section back yoke 21a.

[0319] This causes the magnetic flux Mmg of the drive-side magnet to flow so as to further avoid the magnetic flux Mmt of the motor section 11 downward, as shown in FIG. 49, thereby further reducing magnetic interference and further improving performance.

[0320] In other words, in the axial direction of the driving side magnet 20, i.e., the vertical direction in Figure 48, the central position of the driving side magnet 20, pole piece 25 and fixed magnet 40 is lower than the central position Umt of the stator 12, rotor 13 and motor section back yoke 21a, so that the magnetic flux Mmg of the driving side magnet flows so as to further avoid the magnetic flux Mmt of the motor section 11 downward, thereby reducing magnetic interference.

[0321] The thickness Trc of the rotor cup 21b in the axial direction of the drive-side magnet 20, i.e., the vertical direction in FIG. 49, is greater than the thickness Tby of the motor section back yoke 21a in the radial direction of the drive-side magnet 20, i.e., the horizontal direction in FIG.

[0322] This makes it easier for the magnetic flux Mmg of the drive-side magnet to flow so as to avoid the magnetic flux Mmt of the motor section 11 toward the rotor cup side, as shown in FIG. 49, thereby reducing magnetic interference and improving performance.

[0323] (Other embodiments) Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments.

[0324] (1) In the above embodiment, the corners at the boundary between the sealing cylindrical portion 51b and the sealing bottom portion 51c are rounded with a predetermined radius of curvature, but the corners at the boundary between the sealing cylindrical portion 51b and the sealing bottom portion 51c may be right angles.

[0325] (2) In the above embodiment, the axial length Lp of the pole piece 25 is shorter than the axial length L2 of the fixed magnet 40, and the axial length L2 of the fixed magnet 40 is longer than the axial length L1 of the driving-side magnet 20, but the axial length Lp of the pole piece 25 and the axial length L2 of the fixed magnet 40 may be the same. The axial length L1 of the driving-side magnet 20 and the axial length L2 of the fixed magnet 40 may be the same.

[0326] (3) In the above embodiment, the sealing plate 51 is molded as a single piece. However, if at least the sealing cylindrical portion 51b of the sealing plate 51 is formed from a single member, the sealing cylindrical portion 51b can be made thinner while maintaining pressure resistance, thereby reducing magnetic resistance.

[0327] (4) In the above embodiment, the fixed magnet 40 is fixed to the inner circumferential surface of the main cylindrical portion 50b via the back yoke 56, but the fixed magnet 40 may be fixed directly to the inner circumferential surface of the main cylindrical portion 50b.

[0328] (5) In the above embodiment, the first expansion valve 113 is disposed vertically in the vehicle, but the first expansion valve 113 may be disposed horizontally in the vehicle. The horizontal disposition means that the axial direction of the valve body 48 is substantially parallel to the front-rear and left-right directions of the vehicle. The first expansion valve 113 may be disposed upside down compared to the first embodiment.

[0329] (6) In the above embodiment, the axis alignment portion 15a is integrated with the motor case 15. However, the axis alignment portion may be integrated with the housing 50 and the sealing plate 51, and the motor case may be fixed by screws or the like.

[0330] (7) In the above-described embodiment, the occurrence of locking of the pole piece 25, etc. is constantly monitored by determining whether or not the lock determination condition is satisfied at the start of the vehicle, at the start of the automotive air conditioner, and during air conditioning operation in accordance with the flowchart shown in FIG. 12.

[0331] However, the timing of the lock determination control and the determination of the lock determination condition is not limited to the above timing and can be changed as appropriate. For example, instead of the flowchart shown in FIG. 5, the flowchart shown in FIG. 45 can be executed.

[0332] As shown in Fig. 45, first, in step S21, it is determined whether or not an error occurrence signal has been received. If an error occurrence signal has been received, the process proceeds to step S22, and if an error occurrence signal has not been received, the lock determination control shown in Fig. 45 is terminated.

[0333] Here, the error occurrence signal is a control signal output from an externally disposed control device, and is output when it is believed that there is an error in the operation of the power transmission device 1. For example, when the refrigerant temperature or refrigerant pressure in the refrigeration cycle of the vehicle air conditioner indicates an obviously abnormal value, the air conditioning control device of the vehicle air conditioner outputs the error occurrence signal.

[0334] In step S22, the motor unit 11 is driven to check the operation of the power transmission device 1. At this time, similar to step S2 and the like, the rotor 13 is operated at a constant rotation. In step S23, a signal analysis process is performed on the output signal (e.g., input current) output by driving the motor unit 11 in step S22. The contents of the signal analysis process are similar to those of step S3 and the like, and frequency analysis is performed on the output signal.

[0335] In step S24, it is determined whether or not a lock determination condition is met. If the lock determination condition is met, it is determined that the pole piece 25, etc. is stuck and in a locked state, and in step S25, a lock occurrence signal is output.

[0336] If the lock determination condition is not satisfied, in step S26, it is determined that the drive-side magnet 20 and the pole piece 25 are in a normal state in which they can rotate, and a normal signal is output. The normal signal indicates that the drive-side magnet 20 and the pole piece 25 are in a normal state in which they rotate together.

[0337] 45, the lockup determination control according to the modified example is configured to perform drive of the motor unit 11, frequency analysis, and determination regarding the lockup determination conditions upon receipt of an error occurrence signal from outside. Therefore, the power transmission device 1 according to the modified example can determine whether or not a lockup has occurred in the pole piece 25, etc., at an appropriate timing. Also, the processing load on the lockup determination unit 71 can be reduced compared to a configuration in which constant monitoring is performed.

[0338] (8) In the above embodiment, the power transmission device 1 is applied to the expansion valve of a vapor compression refrigeration cycle. However, as shown in Figures 46 and 47, the power transmission device 1 can also be applied to rotary machines such as a flow control valve 200 and a small pump 300.

[0339] The flow rate regulating valve 200 adjusts the flow rate of the fluid in a flow path 202 by rotating a valve element 201 by a predetermined angle using a driving force transmitted by the power transmission device 1 to adjust the opening degree of the flow path 202 .

[0340] The miniature pump 300 continuously rotates the impeller 301 by the driving force transmitted by the power transmission device 1 to suck in and discharge the fluid.

[0341] (9) In the twentieth embodiment, the reinforcing plate 59 is fastened to the sealing plate 51 by the bolts 80. However, the reinforcing plate 59 may be fixed to the sealing plate 51 by riveting, caulking, welding, or the like. [Explanation of symbols]

[0342] 15 Motor case (housing) 20 Drive side magnet 25 pole pieces 40 Fixed Magnet 50 Main body (housing) 51 Sealing plate (sealing member) 51b sealing cylindrical part 51c Sealing bottom part 113a Drive side space 113b Driven-side space

Claims

1. A rotating drive magnet (20) having multiple poles; A housing (15, 50) that houses the driving side magnet; A fixed magnet (40) having a larger number of poles than the driving magnet and fixed to the housing; a pole piece (25) having a plurality of magnetic portions (25a) and rotating by modulating magnetic flux between the driving magnet and the fixed magnet; a sealing member (51) that divides the inside of the housing into a driving-side space (113a) on the side where the driving-side magnet is arranged and a driven-side space (113b) on the side where the fixed magnet and the pole piece are arranged, and seals a fluid between the driving-side space and the driven-side space, The pole piece and the fixed magnet are cylindrical and disposed coaxially and radially outwardly of the driving magnet, The sealing member has a cylindrical sealing portion (51b) located radially outward from the drive-side magnet, and a bottom sealing portion (51c) that closes the cylindrical sealing portion from the drive-side space side.

2. The number (Npp) of the magnetic body portions (25a) is, relative to the number of poles (Pin) of the drive magnet and the number of poles (Pf) of the fixed magnet, Npp=(Pin+Pf) / 2 2. The power transmission device according to claim 1, wherein the relationship is:

3. The housing has a cylindrical housing portion (50b) that surrounds the driving side magnet, the fixed magnet, and the pole piece from the radially outer side, Further, a back yoke (56) is provided which is made of a magnetic material and has a cylindrical shape and is fixed to the inner peripheral surface of the cylindrical portion of the housing, 3. The power transmission device according to claim 1, wherein the fixed magnet is fixed to an inner peripheral surface of the back yoke.

4. The housing has a cylindrical housing portion (50b) that surrounds the driving side magnet, the fixed magnet, and the pole piece from the radially outer side, 3. The power transmission device according to claim 1, wherein the fixed magnet is fixed to an inner circumferential surface of the cylindrical portion of the housing.

5. 5. The power transmission device according to claim 3, wherein the cylindrical portion of the housing is made of a magnetic material.

6. A bearing member (49) is provided to rotatably support the pole piece relative to the housing, A power transmission device as described in any one of claims 1 to 5, wherein, in the axial direction of the driving side magnet, the end of the pole piece opposite the bearing member is located on the opposite side of the bearing member relative to a virtual line (lv) connecting the end of the driving side magnet opposite the bearing member and the end of the fixed magnet opposite the bearing member.

7. 7. The power transmission device according to claim 1, wherein the pole piece is shorter than the driving magnet and the fixed magnet in the axial direction of the driving magnet.

8. 8. The power transmission device according to claim 1, wherein the fixed magnet is longer than the driving side magnet in an axial direction of the driving side magnet.

9. 9. The power transmission device according to claim 1, wherein the driving side magnet is longer than the pole piece and shorter than the fixed magnet in an axial direction of the driving side magnet.

10. The housing includes: A cylindrical housing portion (50b) that surrounds the driving side magnet, the fixed magnet, and the pole piece from the radial outside; 10. The power transmission device according to claim 1, further comprising an axis alignment portion (15a) fixed to the cylindrical portion of the housing for axially aligning the driving magnet with the pole piece.

11. 11. The power transmission device according to claim 1, wherein the cylindrical sealing portion is formed from a single non-magnetic member.

12. The sealing member has a sealing upper surface portion (51 a) extending radially outward from an end portion of the sealing cylindrical portion opposite to the sealing bottom surface portion, 11. The power transmission device according to claim 1, wherein the upper sealing portion, the cylindrical sealing portion and the bottom sealing portion are formed from a single non-magnetic member.

13. An output shaft (41) that rotates integrally and coaxially with the pole piece, 13. The power transmission device according to claim 1, wherein the sealed bottom portion has a driven-side bearing portion (51e) that rotatably supports the output shaft.

14. An input shaft (14) that rotates coaxially with the driving magnet, 14. The power transmission device according to claim 1, wherein the sealed bottom portion has a drive-side bearing portion (51d) that rotatably supports the input shaft.

15. 15. The power transmission device according to claim 1, wherein the driven-side space is a space in which a fluorocarbon-based refrigerant is present.

16. The pole piece drives a valve body (48) of an expansion valve (113) that reduces pressure and expands the refrigerant in a vapor compression refrigeration cycle (110).

15. The power transmission device according to claim 1, wherein the driven-side space is a space in which the refrigerant exists.

17. The pole piece is adapted to drive a valve body (201) of a flow control valve (200) that adjusts the flow rate of a fluid, 15. The power transmission device according to claim 1, wherein the driven-side space is a space in which the fluid exists.

18. The pole piece is adapted to drive an impeller (301) of a pump (300) for moving a fluid; 15. The power transmission device according to claim 1, wherein the driven-side space is a space in which the fluid exists.

19. a motor unit (11) that outputs a driving force for rotating the driving side magnet by electromagnetic force; and a lock determination unit (71) that determines whether or not the pole piece is locked by using a fluctuation in rotational load related to the operation of the drive side magnet.

20. 20. The power transmission device according to claim 19, wherein the number of poles (Pm) of the motor portion is different from the number of poles (Pin) of the drive-side magnet.

21. A power transmission device as described in claim 19, wherein 1 / 2 of the number of poles (Pm) of the motor section is different from the least common multiple of 1 / 2 the number of poles (Pin) in the drive side magnet and 1 / 2 the number of poles (Pf) in the fixed magnet, and the least common multiple of the number of poles of the motor section and the number of slots (Ns) in the motor section is different from the least common multiple of 1 / 2 the number of poles (Pf) in the fixed magnet and 1 / 2 the number of poles (Pf) in the fixed magnet.

22. 22. The power transmission device according to claim 19, wherein the lock determination unit performs a frequency analysis of an input current to the motor unit, and determines that a lock of the pole piece has occurred when the input current at a predetermined specific frequency (fs) exceeds a reference value.

23. The motor unit is a three-phase motor (11a), 22. The power transmission device according to claim 19, wherein the lock determination unit performs a frequency analysis on a drive current of the three-phase motor, and determines that a lock of the pole piece has occurred when the drive current of a predetermined specific frequency (fs) exceeds a reference value.

24. The motor section is a DC motor (11c) having a commutator and brushes, 22. The power transmission device according to claim 19, wherein the lock determination unit performs a frequency analysis on a drive current of the DC motor, and determines that a lock of the pole piece has occurred when the drive current of a predetermined specific frequency (fs) exceeds a reference value.

25. The motor unit is a three-phase motor (11a), a three-phase inverter circuit (72) for determining a duty ratio, which is a ratio of an on time to an off time in the three-phase motor, from a relationship between a predetermined triangular wave and a determination voltage determined in conjunction with a fluctuation in the rotation load; 22. The power transmission device according to claim 19, wherein the lock determination unit performs a frequency analysis on the determination voltage, which changes in conjunction with a fluctuation in the rotation load, and determines that a lock of the pole piece has occurred when the determination voltage at a predetermined specific frequency (fs) exceeds a reference value.

26. The motor unit is a three-phase motor (11a), 22. The power transmission device according to claim 19, wherein the lock determination unit performs a frequency analysis on a current of any one of the phases in the three-phase motor, and determines that a lock of the pole piece has occurred when the current of the one phase at a predetermined specific frequency (fsa, fsb) exceeds a reference value.

27. The motor unit is a three-phase motor (11a), 22. The power transmission device according to claim 19, wherein the lock determination unit performs a frequency analysis on the line voltages for any two phases of the three-phase motor, and determines that the pole piece is locked when the line voltages at predetermined specific frequencies (fsa, fsb) exceed a reference value.

28. an acceleration sensor (73d) for detecting acceleration caused by vibration accompanying fluctuations in the rotation load; 22. The power transmission device according to claim 19, wherein the lock determination unit performs a frequency analysis on the acceleration detected by the acceleration sensor, and determines that a lock of the pole piece has occurred when a change in the acceleration at a predetermined specific frequency (fs) exceeds a reference value.

29. The motor unit (11) includes a stator (12) having slots around which coils (12a) are wound, and a rotor (13) having a magnet and rotating therewith, and drives the drive-side magnet by the rotor; The slots are provided in a plurality for each phase, 29. The power transmission device according to claim 1, wherein the driving side magnet is configured so that induced voltages generated in the coil by the driving side magnet are offset in each phase.

30. The motor unit (11) includes a stator (12) having slots around which coils (12a) are wound, and a rotor (13) having a magnet and rotating therewith, and drives the drive-side magnet by the rotor; The slots are provided in a plurality for each phase and are evenly arranged in the circumferential direction of the rotor, The winding direction of the coil is the same in each of the slots, The plurality of poles (20n, 20s) of the driving side magnet are evenly arranged in the circumferential direction of the rotor, 29. A power transmission device according to claim 1, wherein the number of pole pairs of the drive magnet is different from a multiple of the number of slots of each phase.

31. The motor unit (11) includes a stator (12) having slots around which coils (12a) are wound, and a rotor (13) having a magnet and rotating therewith, and drives the drive-side magnet by the rotor; The slots are provided in a plurality for each phase and are evenly arranged in the circumferential direction of the rotor, The number of slots in each phase is equal to the number of slots in which the coil is wound right-handed and left-handed, The plurality of poles (20n, 20s) of the driving side magnet are evenly arranged in the circumferential direction of the rotor, 29. A power transmission device according to claim 1, wherein the number of pole pairs of the drive magnet is different from an odd multiple of half the number of slots of each phase.

32. 32. The power transmission device according to claim 29, wherein the rotor, the stator and the drive-side magnet are arranged side by side in a radial direction of the rotor.

33. 32. The power transmission device according to claim 29, wherein the rotor, the stator and the drive-side magnet are arranged side by side in the axial direction of the rotor.

34. The motor unit (11) includes a stator (12) having a coil (12a) and a rotor (13) having a magnet and rotating, and drives the drive-side magnet by the rotor. The driving magnet is cylindrical.

29. The power transmission device according to claim 1, wherein the stator and the rotor are disposed inside the driving side magnet.

35. 35. The power transmission device according to claim 34, further comprising an intervening member (21) made of a magnetic material and disposed between the rotor and the drive-side magnet.

36. A stator (12) having a coil (12a), The driving magnet is cylindrical.

29. The power transmission device according to claim 1, wherein the stator is disposed inside the driving side magnet and rotates the driving side magnet as a rotor.

37. a circuit board (701) arranged in the driving-side space at a position overlapping the sealing member and the driving-side magnet in the axial direction; a circuit element (702) that is disposed at a position on the circuit board that overlaps with the sealing member and the driving side magnet in the axial direction and generates radiation noise; 37. A power transmission device according to claim 1, wherein the sealing member is made of a conductor.

38. an input shaft (14) that is disposed in the drive-side space and rotates coaxially with the drive-side magnet; a reinforcing plate (59) disposed on the opposite side of the sealing member with respect to the circuit board in the drive-side space and reinforcing a bearing portion of the input shaft, the reinforcing plate is made of a conductor, 38. The power transmission device according to claim 37, wherein the circuit element is disposed at a position overlapping with the reinforcing plate and the driving-side magnet in the axial direction.

39. The housing has a main body portion (50) that forms the driven-side space and a case (15) that forms the driving-side space, The main body is made of a conductor, The sealing member is fixed to the body portion, The sealing member has a fixing portion (51f) to which the reinforcing plate is fixed, 39. The power transmission device according to claim 38, wherein the fixing portion electrically connects the sealing member and the reinforcing plate.

40. the circuit element is disposed on the circuit board so as to face the sealing member side, The housing has a main body portion (50) that forms the driven-side space and a case (15) that forms the driving-side space, 40. The power transmission device according to claim 37, wherein the case is made of a conductor and closes the gap between the sealing member and the circuit board from the radial outside of the drive-side magnet.

41. an input shaft (14) that is disposed in the drive-side space and rotates coaxially with the drive-side magnet; A reinforcing plate (59) for reinforcing a bearing portion of the input shaft in the drive-side space; a circuit board (701) disposed in the drive-side space so as to face the sealing member and fixed to the reinforcing plate; A circuit element (702) joined to the circuit board by solder (704), 37. The power transmission device according to claim 1, wherein the sealing member has a fixing portion (51f) to which the reinforcing plate is fixed.

42. The fixing portion is provided in at least three places, 42. The power transmission device according to claim 41, wherein the circuit elements are arranged on the circuit board within an inner range (A1) of an imaginary circumscribing circle that circumscribes all of the fixed portions.

43. The fixing portion is provided in at least two places, The power transmission device according to claim 41, wherein the circuit element is disposed in a range (A2) between the fixing portions on the circuit board.

44. the intermediate member has a cylindrical motor section back yoke (21 a) disposed between the rotor and the driving-side magnet, and a rotor cup (21 b) that closes the back yoke from one axial end side of the driving-side magnet, the motor back yoke and the rotor cup are made of a magnetic material, A power transmission device as described in claim 35, wherein, in the axial direction of the driving side magnet, the end position (Bmg) of the driving side magnet, the pole piece and the fixed magnet at one axial end side is located farther from the motor unit than the end positions (Bmt) of the stator, the rotor and the motor unit back yoke at one axial end side.

45. 45. The power transmission device of claim 44, wherein a thickness (Trc) of the rotor cup in the axial direction of the drive side magnet is greater than a thickness (Tby) of the motor section back yoke in the radial direction of the drive side magnet.

46. the intermediate member has a cylindrical motor back yoke (21 a) disposed between the rotor and the drive-side magnet, and a rotor cup (21 b) that closes the motor back yoke from one axial end side of the drive-side magnet, 36. The power transmission device according to claim 35, wherein a thickness (Trc) of the rotor cup in the axial direction of the drive side magnet is greater than a thickness (Tby) of the motor unit back yoke in the radial direction of the drive side magnet.

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