Magnetic fluid motor

Abstract

To provide a magnetic fluid motor in which a linear cluster can be applied to a motor.SOLUTION: A magnetic fluid motor comprises: a first magnetic field generation part which has a coil wound around each of a plurality of teeth, and is provided to generate a revolving magnetic field; a second magnetic field generation part which has a coil wound around each of the plurality of teeth, can generate the revolving magnetic field, and is provided to face the first magnetic field generation part; a rotor which is rotatably provided with a revolving shaft between the first magnetic field generation part and the second magnetic field generation part; and magnetic fluid provided around the rotor in a space between the first magnetic field generation part and the second magnetic field generation part. The rotor is periodically provided with magnetic material parts in an area in a circumferential direction corresponding to the first magnetic field generation part and the second magnetic field generation part, a linear cluster of the magnetic fluid is generated between the first magnetic field generation unit and the magnetic material parts and between the magnetic material parts and the second magnetic field generation part by the revolving magnetic field to drive the rotor by rotation by movement of the linear cluster with the revolving magnetic field.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a magnetic fluid motor.

Background Art

[0002] When a magnetic field is applied to a magnetic fluid in which magnetic particles are dispersed in a liquid, the magnetic particles attract each other and aggregate to form chain-like clusters (hereinafter referred to as "chain clusters"). If a magnetic fluid is injected between a moving body and a fixed body and a magnetic field is applied between the moving body and the fixed body, the collapse and formation of chain clusters are repeated between the moving body and the fixed body, generating a resistance force. This resistance force is the braking force by the magnetic fluid. Such a method of using a magnetic fluid is described in Patent Document 1.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the magnetic fluid as described above, the resistance force by the chain clusters has been only used for braking. For this reason, it has been desired to apply the magnetic fluid to active applications, for example, driving of a motor.

[0005] An object of the present invention is to provide a magnetic fluid motor in which chain clusters by a magnetic fluid can be applied to a motor.

Means for Solving the Problems

[0007] The rotor may be configured such that magnetic and non-magnetic portions are alternately provided in the circumferential region.

[0008] The coils of the first magnetic field generating unit and the coils of the second magnetic field generating unit may each be wound in three phases, and when a three-phase alternating current is supplied, they may generate a three-phase rotating magnetic field.

[0009] Non-rotating magnetic fields may be formed in the first magnetic field generating unit and the second magnetic field generating unit, and the rotation of the rotor may be stopped by the chain-like cluster. [Effects of the Invention]

[0010] According to the magnetic fluid motor of the present invention, the rotor is driven to rotate by the movement of chain-like clusters of magnetic fluid together with the rotating magnetic field, making it possible to apply chain-like clusters of magnetic fluid to the motor. [Brief explanation of the drawing]

[0011] [Figure 1] This is a partially broken side view showing the schematic configuration of a magnetic fluid motor according to Embodiment 1. [Figure 2]This is a cross-sectional view showing the section along line II-II in Figure 1. [Figure 3] This is a cross-sectional view showing the section along line III-III in Figure 1. [Figure 4] This is a cross-sectional view showing the section along line IV-IV in Figure 1. [Figure 5] This is an explanatory diagram showing the three-phase alternating current supplied to the magnetic fluid motor according to Embodiment 1. [Figure 6] This is an explanatory diagram showing the direction of the magnetic field generated in the coil of the magnetic field generation unit supplied with the three-phase alternating current to the magnetic fluid motor according to Embodiment 1. [Figure 7] This is an explanatory diagram showing a chain-like cluster in a cross-sectional view of a magnetic fluid motor according to Embodiment 1. [Figure 8] This is an explanatory diagram showing the expanded positional relationship between the magnetic field generating unit, the magnetic material part of the rotor, and the chain-like cluster when a three-phase alternating current is supplied to the magnetic fluid motor according to Embodiment 1. [Modes for carrying out the invention]

[0012] The embodiments of the magnetic fluid motor will be described below with reference to the drawings. In each figure, the same parts are denoted by the same reference numerals.

[0013] Embodiment 1. First, the basic configuration of the magnetic fluid motor 100 in Embodiment 1 will be described using Figures 1 to 4. Figure 1 is a partially broken side view showing the schematic configuration of the magnetic fluid motor according to Embodiment 1. Figure 2 is a cross-sectional view showing the cross-section along line II-II in Figure 1. Figure 3 is a cross-sectional view showing the cross-section along line III-III in Figure 1. Figure 4 is a cross-sectional view showing the cross-section along line IV-IV in Figure 1.

[0014] In Figures 1 and 2, the magnetic fluid motor 100 mainly comprises a case 101, a rotating shaft 110, a magnetic field generating unit 120, a sealing unit 140, magnetic fluid 150, and a rotor 160.

[0015] The case 101 covers the outer periphery of the cylindrical magnetic fluid motor 100, and is composed of a circular first lid portion 101a forming one end of the magnetic fluid motor 100, a circular second lid portion 101b forming the other end of the magnetic fluid motor 100, and a cylindrical surface portion 101c covering the outer peripheral surface between the first lid portion 101a and the second lid portion 101b.

[0016] The rotating shaft 110 is rotatably supported with respect to the case 101 via bearings 102 and 103. The rotating shaft 110 is configured such that at least one end projects from the second lid portion 101b, and outputs the rotation generated by the magnetic fluid motor 100 to the outside.

[0017] The magnetic field generating unit 120 includes a first magnetic field generating unit 121 and a second magnetic field generating unit 122. The first magnetic field generating unit 121 has a stator 1211, teeth 1212, and a coil 1213, and is provided so as to be able to generate a rotating magnetic field. The stator 1211 is provided so as to contact the first lid portion 101a. As shown in FIG. 3, on the stator 1211, a pair of teeth 1212 (1212U, 1212V, 1212W) are provided for each of the U1 phase, V1 phase, W1 phase, U2 phase, V2 phase, and W2 phase corresponding to the three phases of UVW. And coils 1213 (1213U, 1213V, 1213W) are wound around the pair of teeth 1212 (1212U, 1212V, 1212W) of the U1 phase, V1 phase, W1 phase, U2 phase, V2 phase, and W2 phase, respectively.

[0018] The second magnetic field generating unit 122 has a stator 1221, teeth 1222, and a coil 1223, and is provided so as to be able to generate a rotating magnetic field. The stator 1221 is provided so as to contact the second lid portion 101b. As in FIG. 3, on the stator 1221, a pair of teeth 1222 are provided for each of the U1 phase, V1 phase, W1 phase, U2 phase, V2 phase, and W2 phase corresponding to the three phases of UVW. And as in FIG. 3, coils 1223 are wound around the pair of teeth 1222, respectively.

[0019] The sealing portion 140 contains the magnetic fluid 150 in the space between the first magnetic field generating portion 121 and the second magnetic field generating portion 122, and prevents the magnetic fluid 150 from leaking to the outside. It comprises a sealing portion 140a on the side of the first magnetic field generating portion 121 and a sealing portion 140b on the side of the second magnetic field generating portion 122.

[0020] The magnetic fluid 150 has magnetic particles dispersed in a liquid state, and has the property of forming chain-like clusters by attracting each other and agglomerating in response to a magnetic field. The magnetic fluid 150 is contained within a space surrounded by the seal portion 140a, the seal portion 140b, and the cylindrical surface portion 101c, and covers the rotor 160.

[0021] The rotor 160 is rotatable together with the rotation shaft 110, surrounded by magnetic fluid 150 between the first magnetic field generating unit 121 and the second magnetic field generating unit 122. As shown in Figures 4(a) and 4(b), the rotor 160 has alternating magnetic material portions 161 and non-magnetic material portions 162 at predetermined angular intervals in the circumferential regions corresponding to the first magnetic field generating unit 121 and the second magnetic field generating unit 122. The direction along the rotation direction of the rotor 160 is referred to as the "circumferential direction". In the rotor 160, regions other than those where magnetic material portions 161 and non-magnetic material portions 162 alternate may be magnetic, as shown in Figure 4(a), or non-magnetic, as shown in Figure 4(b).

[0022] Referring to Figure 5, the three-phase alternating current supplied to the magnetic field generating unit 120 of the magnetic fluid motor 100 will be explained. Figure 5 is an explanatory diagram showing the three-phase alternating current supplied to the magnetic fluid motor 100 according to Embodiment 1.

[0023] In Figure 5, the horizontal axis represents the phase angle of the current (0° to 360°), and the vertical axis represents the maximum current normalized to 1 and -1. The currents of the U, V, and W phases each have a phase difference of 120° and are sinusoidal three-phase alternating currents that increase and decrease. In the first embodiment of the magnetic fluid motor 100, the magnetic fluid 150 surrounding the rotor 160 aggregates most strongly at the timing when the current value is maximum, regardless of the positive or negative direction of the current, forming chain-like clusters. Therefore, in the case of the three-phase AC current shown in Figure 5, chain-like clusters are most strongly formed at a phase angle of 0° (U in Figure 5(a)), a phase angle of 60° (-W in Figure 5(b)), a phase angle of 120° (V in Figure 5(c)), a phase angle of 180° (-U in Figure 5(d)), a phase angle of 240° (W in Figure 5(e)), and a phase angle of 300° (-V in Figure 5(f)).

[0024] Referring to Figure 6, the direction of the magnetic field generated in each coil of the first magnetic field generating unit 121 by the three-phase alternating current supplied to the magnetic fluid motor 100 will be explained. Figure 6 is an explanatory diagram showing the direction of the magnetic field generated in the coil of the first magnetic field generating unit 121 by the three-phase alternating current supplied to the magnetic fluid motor 100 according to Embodiment 1. Although not shown in Figure 6, the direction of the magnetic field generated in the coil of the second magnetic field generating unit 122 is opposite to the direction of the magnetic field generated in the coil of the first magnetic field generating unit 121, i.e., it is configured to be complementary.

[0025] In Figure 6, a black circle inside a circle indicates a magnetic field directed towards the viewer perpendicular to the plane of the paper, while an X inside a circle indicates a magnetic field directed away from the viewer perpendicular to the plane of the paper. The size of the symbols indicates the strength of the magnetic field corresponding to the current value in Figure 5. The magnetic fields shown in Figures 6(a) to 6(f) correspond to the currents shown in Figures 5(a) to 6(f), respectively.

[0026] Figure 6(a) shows the magnetic field at the maximum current value U (Figure 5(a)) at a phase angle of 0° for the three-phase AC current, with the magnetic field being maximum in the U1 and U2 phases. Figure 6(b) shows the magnetic field at the maximum current value -W (Figure 5(b)) at a phase angle of 60° for the three-phase AC current, with the magnetic field being maximum in the W1 and W2 phases. Figure 6(c) shows the magnetic field at the maximum current value V (Figure 5(c)) at a phase angle of 120° for the three-phase AC current, with the magnetic field being maximum in the V1 and V2 phases. Figure 6(d) shows the magnetic field at the maximum current value -U (Figure 5(d)) at a phase angle of 180° for the three-phase AC current, with the magnetic field being maximum in the U1 and U2 phases. Figure 6(e) shows the magnetic field at the maximum current value W (Figure 5(e)) at a phase angle of 240° for the three-phase AC current, with the magnetic field being maximum in the W1 and W2 phases. Figure 6(f) shows the magnetic field that is maximum in the V1 and V2 phases at the current value -V maximum (Figure 5(f)) at a phase angle of 300° for the three-phase AC current.

[0027] When the current value of the three-phase alternating current reaches its maximum in any of the coils of the magnetic field generating unit 120, and the rotor 160 is a magnetic material 161 at a position sandwiched between those coils, a chain-like cluster 151 as shown in Figure 7 is formed in the magnetic fluid 150. Figure 7 is an explanatory diagram showing the chain-like cluster 151 in a cross-sectional view of the magnetic fluid motor 100 according to Embodiment 1. In the magnetorheological motor 100 of Embodiment 1, a three-phase alternating current is supplied to the magnetic field generating unit 120 to generate a three-phase rotating magnetic field, so the chain-like cluster 151 also rotates and moves along with the rotating magnetic field.

[0028] The following describes how the rotor 160 is driven to rotate by the chain-like clusters 151 that move together with the rotating magnetic field, with reference to Figure 8. Figure 8 is an explanatory diagram showing the positional relationship between the magnetic field generating unit 120 (first magnetic field generating unit 121 and second magnetic field generating unit 122), the magnetic material part 161 of the rotor 160, and the chain-like clusters 151 in an unfolded state when a three-phase alternating current is supplied to the magnetic fluid motor 100 according to Embodiment 1. Here, "unfolded" means a state in which the magnetic field generating unit 120 and the rotor 160 are represented on a plane as viewed from the outer circumference of 360°.

[0029] In the following explanation of Figure 8, the positions of the U-phase, V-phase, and W-phase of the first magnetic field generating unit 121 and the second magnetic field generating unit 122 are simply referred to as the U-phase position, V-phase position, and W-phase position. In the rotor 160, the four magnetic material parts 161 located in the circumferential direction as shown in Figure 4 are referred to as magnetic material R1 to R4. The coils 1213 and 1223 at the U, V, and W-phase positions are referred to as the U, V, and W-phase coils. In Figure 8, the portion where the maximum current is supplied to either the first magnetic field generating unit 121 or the second magnetic field generating unit 122 is indicated by cross-hatching.

[0030] In Figure 8(a), magnetic materials R1 and R3 are located at the U-phase position, and magnetic materials R2 and R4 are located at an intermediate position that spans both the V-phase and W-phase positions. In Figure 8(a), when the maximum current of the three-phase alternating current is supplied to the coil in the U-phase position (see Figures 5 and 6(a)), chain-like clusters 151 are generated between the first magnetic field generating unit 121 and magnetic materials R1 and R3, and between the second magnetic field generating unit 122 and magnetic materials R1 and R3 in the U-phase position. This state is referred to as the generation of chain-like clusters 151 between magnetic materials R1 and R3 in the U-phase position. The same applies to the V-phase and W-phase regions.

[0031] In Figure 8(b1), the rotor 160 is in the same position as in Figure 8(a). In Figure 8(b1), when the maximum current of the three-phase alternating current is supplied to the coil in the W-phase position (see Figures 5 and 6(b)), chain-like clusters 151 are generated in the W-phase position in the regions of half of the magnetic material R2 and half of the magnetic material R4. Here, because chain-like clusters 151 are attempting to be generated in the entire region of the W-phase position, a force directed to the right in the figure is generated that attempts to pull the magnetic material R2 and magnetic material R4 to the W-phase position. As a result, the rotor 160 rotates, and magnetic materials R2 and R4 come to be located in the W phase position in Figure 8(b2), and chain-like clusters 151 are generated in magnetic materials R2 and R4 throughout the entire W phase region. Furthermore, as the rotor 160 rotates, magnetic materials R1 and R3 come to be located in an intermediate position that spans both the U phase and V phase positions.

[0032] In Figure 8(c1), the rotor 160 is in the same position as in Figure 8(b2). In Figure 8(c1), when the maximum current of the three-phase alternating current is supplied to the coil in the V-phase position (see Figures 5 and 6(c)), chain-like clusters 151 are generated in the V-phase position in the region of half of the magnetic material R1 and half of the magnetic material R3. Here, because chain-like clusters 151 are trying to be generated in the entire region of the V-phase position, a force directed to the right in the figure is generated that tries to pull the magnetic material R1 and magnetic material R3 to the V-phase position. As a result, the rotor 160 rotates, and magnetic materials R1 and R3 come to be located in the V-phase position in Figure 8(c2), and chain-like clusters 151 are generated in magnetic materials R1 and R3 throughout the entire V-phase region. Furthermore, as the rotor 160 rotates, magnetic materials R2 and R4 come to be located in an intermediate position that spans both the W-phase and U-phase positions.

[0033] In Figure 8(d1), the rotor 160 is in the same position as in Figure 8(c2). In Figure 8(d1), when the maximum current of the three-phase alternating current is supplied to the coil in the U-phase position (see Figures 5 and 6(d)), chain-like clusters 151 are generated in the region of half of the magnetic material R4 and half of the magnetic material R2 in the U-phase position. Here, because chain-like clusters 151 are trying to be generated in the entire region of the U-phase position, a force directed to the right in the figure is generated that tries to pull the magnetic materials R2 and R4 to the U-phase position. As a result, the rotor 160 rotates, and in Figure 8 (d2), magnetic materials R4 and R2 come to be present in the U-phase position, and chain-like clusters 151 are generated in magnetic materials R4 and R2 throughout the entire U-phase region. Furthermore, as the rotor 160 rotates, magnetic materials R1 and R3 come to be present in an intermediate position that spans both the V-phase and W-phase positions.

[0034] In Figure 8(e1), the rotor 160 is in the same position as in Figure 8(d2). In Figure 8(e1), when the maximum current of the three-phase alternating current is supplied to the coil in the W-phase position (see Figures 5 and 6(e)), chain-like clusters 151 are generated in the W-phase position in the region of half of the magnetic material R1 and half of the magnetic material R3. Here, because chain-like clusters 151 are trying to be generated in the entire region of the W-phase position, a force directed to the right in the figure is generated that tries to pull the magnetic material R1 and magnetic material R3 to the W-phase position. As a result, the rotor 160 rotates, and magnetic materials R1 and R3 come to be located in the W phase position in Figure 8(e2), and chain-like clusters 151 are generated in magnetic materials R1 and R3 throughout the entire W phase region. Furthermore, as the rotor 160 rotates, magnetic materials R2 and R4 come to be located in an intermediate position that spans both the U phase and V phase positions.

[0035] In Figure 8(f1), the rotor 160 is in the same position as in Figure 8(e2). In Figure 8(f1), when the maximum current of the three-phase alternating current is supplied to the coil in the V-phase position (see Figures 5 and 6(f)), chain-like clusters 151 are generated in the V-phase position in the region of half of the magnetic material R4 and half of the magnetic material R2. Here, because chain-like clusters 151 are trying to be generated in the entire region of the V-phase position, a force directed to the right in the figure is generated that tries to pull the magnetic material R2 and magnetic material R4 to the V-phase position. As a result, the rotor 160 rotates, and in Figure 8 (f2), magnetic materials R4 and R2 come to be present in the V-phase position, and chain-like clusters 151 are generated in magnetic materials R4 and R2 throughout the entire V-phase region. Furthermore, as the rotor 160 rotates, magnetic materials R1 and R3 come to be present in an intermediate position that spans both the W-phase and U-phase positions.

[0036] As described above, by supplying a three-phase alternating current to the magnetic field generating unit 120 of the magnetic fluid motor 100, chain-like clusters 151 that move with the rotating magnetic field are generated around the rotor 160, driving the rotor 160 to rotate. In other words, according to the magnetic fluid motor 100 of Embodiment 1, it becomes possible to apply chain-like clusters 151 to the motor.

[0037] In the magnetic fluid motor 100, by stopping the supply of three-phase alternating current to the magnetic field generating unit 120 and supplying direct current to only one of the UVW phases, a non-rotating magnetic field can be formed in the magnetic field generating unit 120, keeping the chain-like clusters 151 in the same place and stopping the rotation of the rotor 160.

[0038] [Effects obtained by the embodiment] The magnetic fluid motor 100 described in Embodiment 1 comprises: a first magnetic field generating unit 121 having coils 1213, 1223 wound around each of a plurality of teeth 1212, 1222 and capable of generating a rotating magnetic field; a second magnetic field generating unit 122 having coils 1213, 1223 wound around each of a plurality of teeth 1212, 1222 and capable of generating a rotating magnetic field, and provided opposite the first magnetic field generating unit 121; a rotor 160 provided between the first magnetic field generating unit 121 and the second magnetic field generating unit 122 so as to be rotatable together with the rotating shaft 110; and a magnetic fluid 150 provided around the rotor 160 in the space between the first magnetic field generating unit 121 and the second magnetic field generating unit 122. Here, the rotor 160 is periodically provided with magnetic material sections 161 in circumferential regions corresponding to the first magnetic field generating section 121 and the second magnetic field generating section 122. The rotating magnetic field generates chain-like clusters 151 of magnetic fluid 150 between the first magnetic field generating section 121 and the magnetic material sections 161, and between the magnetic material sections 161 and the second magnetic field generating section 122. The movement of these chain-like clusters 151 along with the rotating magnetic field drives the rotor 160 to rotate. Thus, the chain-like clusters 151 can be applied to the magnetic fluid motor 100.

[0039] The rotor 160 is provided with alternating magnetic and non-magnetic portions 161 and non-magnetic portions 162 in its circumferential region. As a result, regions where chain-like clusters 151 are formed and regions where chain-like clusters 151 are not formed are created, allowing the chain-like clusters 151 to effectively drive the rotor 160 to rotate.

[0040] The coil 1213 of the first magnetic field generating unit 121 and the coil 1223 of the second magnetic field generating unit 122 are each wound in three phases, and when a three-phase alternating current is supplied, they generate a three-phase rotating magnetic field. As a result, the chain-like cluster 151 moves along with the rotating magnetic field, which can rotate the rotor 160.

[0041] When a non-rotating magnetic field is formed in the first magnetic field generating unit 121 and the second magnetic field generating unit 122, the chain-like cluster 151 stops along with the non-rotating magnetic field, thereby stopping the rotation of the rotor 160. [Explanation of Symbols]

[0042] 100 Magnetic fluid motor, 101 Case, 101a First cover, 101b Second cover, 101c Cylindrical surface, 102, 103 Bearings, 110 Rotating shaft, 121 First magnetic field generating section, 122 Second magnetic field generating section, 140, 140a, 140b Seal sections, 150 Magnetic fluid, 151 Chain-like cluster, 160 Rotor, 161 Magnetic material section, 162 Non-magnetic material section, 1211, 1221 Stator, 1212, 1212U, 1212V, 1212W, 1222 Teeth, 1213, 1213U, 1213V, 1213W, 1223 Coil.

Claims

1. A first magnetic field generating unit (121) is provided that has coils (1213) wound around each of a plurality of teeth (1212) and is capable of generating a rotating magnetic field, A second magnetic field generating unit (122) is provided opposite the first magnetic field generating unit (121), and has a coil (1223) wound around each of a plurality of teeth (1222), capable of generating a rotating magnetic field, A rotor (160) is rotatably mounted together with the rotating shaft (110) between the first magnetic field generating unit (121) and the second magnetic field generating unit (122), A magnetic fluid (150) is provided around the rotor (160) in the space between the first magnetic field generating unit (121) and the second magnetic field generating unit (122), A magnetic fluid motor comprising, The rotor (160) is provided with magnetic material portions (161) periodically in circumferential regions corresponding to the first magnetic field generating portion (121) and the second magnetic field generating portion (122). The rotating magnetic field generates chain-like clusters (151) of the magnetic fluid (150) between the first magnetic field generating unit (121) and the magnetic material unit (161), and between the magnetic material unit (161) and the second magnetic field generating unit (122). The chain-like cluster (151) moves together with the rotating magnetic field, thereby driving the rotor (160) to rotate. Magnetic fluid motor.

2. The rotor (160) is provided with alternating magnetic material portions (161) and non-magnetic material portions (162) in the circumferential region. The magnetic fluid motor according to claim 1.

3. The coil (1213) of the first magnetic field generating unit (121) and the coil (1223) of the second magnetic field generating unit (122) are each wound in three phases and generate a three-phase rotating magnetic field when supplied with a three-phase alternating current. The magnetic fluid motor according to claim 1.

4. A non-rotating magnetic field is formed in the first magnetic field generating unit (121) and the second magnetic field generating unit (122), and the rotation of the rotor (160) is stopped by the chain-like cluster (151). A magnetic fluid motor according to any one of claims 1 to 3.

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