JP2009100635A - Method for manufacturing spherical surface motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spherical surface motor capable of increasing the amount of spherical surface operation by solving the problem of a decrease in torque of its own axis during rotation of the other axis, and causing a spherical rotor to perform spherical surface operation at a high angle acceleration by an easy operation without causing step-out, and to provide a highly accurate method for manufacturing the motor. <P>SOLUTION: In the method for manufacturing the spherical surface motor comprising a spherical rotor 1 having a plurality of permanent magnets 3 thereon and a stator 4 having a plurality of windings disposed with a predetermined space from the spherical motor 1, and a winding unit 5 consisting of the winding 211 and the stator 2 is formed, the winding unit 5 is attached on a winding frame 204. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spherical motor used for driving joints such as necks, shoulders, elbows and knees of industrial robots and humanoid robots.

  As a conventional spherical motor in which the tip of the drive shaft operates in spherical coordinates (θ, φ) represented by a tilt angle θ from the vertical Z axis and a rotation angle φ on the horizontal XY plane, for example, drive Permanent magnets placed on the outer circumference around the X and Y axes at a fixed magnetic pole pitch angle on a spherical rotor with a shaft attached (see Patent Documents 1 and 2), and permanent magnets placed in a grid pattern (Refer patent document 3), There exists what arrange | positioned the protrusion of a magnetic material to each vertex of the some triangle inscribed in the surface of a spherical rotor (refer patent document 4). In addition, there is one in which a rotation operation of spherical coordinates (θ, φ) is realized by a link mechanism, and a rotation angle detection means is arranged at one end of a rotation shaft of the link mechanism (see Patent Document 5).

  FIG. 15 is a spherical motor showing the prior art of Patent Document 1. In the figure, 1 is a spherical rotor, 2 is a permanent magnet, 3 is a stator, and 4 is an electromagnet. The spherical motor is composed of a spherical rotor 1 having a permanent magnet 2 disposed on the surface and a stator 3 having an electromagnet 4 disposed thereon. The permanent magnets 2 are arranged at four locations on the outer periphery of the spherical rotor 1, and are arranged so that the upper hemisphere has an N pole and the lower hemisphere has an S pole and two poles at each position. The electromagnets 4 are arranged at positions opposed to the four permanent magnets, and at each position, five electromagnets 4 are arranged in the same direction as the magnetic pole direction of the permanent magnet 2. Although not shown, a spherical bearing is disposed inside the spherical rotor 1 so that the spherical operation of the spherical rotor 1 is free.

In the spherical motor configured as described above, the spherical rotor can be operated in a spherical shape by sequentially exciting the electromagnets 4.
JP 2003-324936 A JP-A-62-081970 JP-A-4-221986 JP-A-9-168275 Japanese Patent Laid-Open No. 4-029552 (pages 3-4, FIG. 1)

In the conventional spherical motor, for example, when the spherical rotor rotates around the X axis, the permanent magnet that generates torque around the Y axis is inclined with respect to the electromagnet, the magnetic pole pitch is shortened, and the side of the electromagnet is The permanent magnet has protruded. As a result, when trying to rotate around the Y axis next time, a torque shortage caused by a decrease in torque occurred, making it impossible to rotate. When an attempt was made to increase the amount of rotational movement, the inclination of the permanent magnet and the electromagnet increased further, and the above-mentioned problems became remarkable, and the amount of rotational movement could not be increased.
In order to solve this problem, magnetic poles such as permanent magnets and magnetic material protrusions are arranged in a grid pattern, or are arranged at the apexes of a plurality of triangles inscribed on the surface of the spherical rotor. However, when rotating around the X axis, the position of the magnetic pole that generates the torque around the Y axis changed with the rotating action around the X axis. In other words, in order to realize the spherical motion, it is necessary to perform excitation control in which the magnetic pole position of the own axis is changed in accordance with the motion of the other axis, and the spherical motion control becomes extremely complicated.
On the other hand, since there is no means for detecting the rotation angle, the excitation control has to be performed by constant current control of the stepping motor or current control by open loop. As a result, the spherical rotor may be stepped out. The structure in which the magnetic poles are made of protrusions and the rotational torque is obtained by reluctance torque is inherently inferior in power factor and the capacity of the drive amplifier is larger than that in which the magnetic poles are made of magnets and the rotational torque is obtained by the magnet torque. .
In order to solve these problems, there are some which have a link mechanism that realizes the rotation operation of the spherical coordinates (θ, φ), and arrange the rotation angle detection means at one end of the rotation shaft of the link mechanism. However, due to the structure in which an electromagnet is placed in the rotating part and the load and weight are supported by the link part, the inertia of the spherical rotor becomes extremely large, and it has not been possible to realize spherical operation with high angular acceleration. .
Further, when assembling a spherical motor, there has been a problem that it is difficult to assemble with a uniform gap between the stator and the mover. In other words, the rotor cannot be inserted after the winding unit configured in the stator is installed, and when the permanent magnet is attached to the rotor after the rotor is inserted into the stator, some permanent magnets There was also a problem that some parts could not be installed.

  The present invention has been made in order to solve the above-described problem, solves the problem of torque reduction of the own shaft during rotation of the other shaft, can increase the spherical motion amount, and can be stepped out with easy control. An object of the present invention is to provide a spherical motor that moves a spherical rotor spherically with high angular acceleration and a highly accurate manufacturing method.

In order to solve the above problem, the present invention is configured as follows.
The invention according to claim 1 is a method of manufacturing a spherical motor comprising a spherical rotor having a plurality of permanent magnets on the surface, and a stator having a plurality of windings arranged via the spherical rotor and a fixed gap. And a winding unit composed of the winding and the stator is formed, and the winding unit is attached to a winding frame.
According to a second aspect of the present invention, a groove for mounting the winding unit is formed in the winding frame.
According to a third aspect of the present invention, when the winding unit is attached to the winding frame, the winding unit is attached to the spherical rotor in a state of being fixed by a magnetic attractive force.
According to a fourth aspect of the present invention, the inner surface of the winding unit is formed in a spherical shape having a constant and uniform gap on the outer surface of the spherical rotor.

  According to the first to fourth aspects of the present invention, a groove for inserting the winding unit is provided in the winding frame, and the spherical rotor and the winding unit are integrally inserted into the winding frame, Since the gap between the movable elements can be assembled with a constant gap, a high torque can be obtained and a spherical operation can be performed with a high angular acceleration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is a perspective view of a spherical motor showing Embodiment 1 of the present invention, FIG. 2 is a sectional view of the horizontal XY plane in FIG. 1, and FIG. 3 is a sectional view of the vertical Z-X plane in FIG. In these figures, the coordinate axes are the X and Y axes horizontally, the Z axis is the vertical axis perpendicular to them, Tx is the rotation around the X axis, Ty is the rotation around the Y axis, and the Z axis of the spherical rotor is from the Z axis. The tilt angle is denoted by θ, and the rotation angle on the horizontal XY plane is denoted by φ.

  1-3, 100 is a spherical rotor, 101 is a shaft, 102 is a trajectory of the shaft 101, 103 is a Tx link, 104 is a Ty link, 110 is a magnet yoke, 111 is a permanent magnet, 200 is a stator, 201 is a base, Reference numeral 202 denotes a leg, 203 a flange, 204 a winding frame, 211 a winding, 300 a rotary bearing, 400 a rotary encoder, 410 a rotary scale, 411 a detection head, and 412 an encoder cover.

  The spherical rotor 100 includes a spherical magnet yoke 110, a permanent magnet 111 disposed on the surface of the magnet yoke 110 made of a magnetic material, and a shaft 101 skewed into the spherical yoke. A ring-shaped Tx link 103 is attached to the upper and lower parts of the shaft 101, and is attached to the Ty link 104 so that the rotary bearing 300 can freely rotate around the X axis at the intersection of the Tx link 103 and the X axis. . The Ty link 104 is also formed in a ring shape, and is attached to the leg 202 so as to be freely rotatable around the Y axis by the rotary bearing 300 at the intersection with the Y axis. The legs 202 are attached to the base 201. A rotary encoder 400 is disposed at the X-axis intersection of the Tx link 103. A rotary scale 410 is attached to a shaft directly connected to the Tx link 103, and a detection head 411 and an encoder cover 412 are attached to the Ty link 104 via the rotary scale 410 and a gap. Similarly, a rotation scale 410 is attached to a shaft directly connected to the Ty link 104 at a Y-axis intersection point of the Ty link 104, and a detection head 411 and an encoder cover 412 are attached to the flange 203. The flange 203 is attached to the leg 202. The spherical rotor 100 of the spherical motor configured as described above operates with the spherical coordinates (θ, φ) on the axis by rotating the stator 200 around the X axis and the Y axis (Tx, Ty). It is supposed to be. Further, the rotation angle (Tx, Ty) is detected by reading the scale of the rotation scale 401 attached to each shaft by the optical detection head 402.

  Next, the arrangement relationship between the permanent magnet and the winding will be described with reference to FIGS. 2 and 3 and newly FIGS. 4 is a permanent magnet arrangement diagram of a spherical rotor, FIG. 5 is an arrangement relation diagram of permanent magnets and windings at a rotation angle (Tx, Ty) = (0, 0), and FIG. 6 is a rotation angle (Tx, Ty) =. It is an arrangement relation figure of a permanent magnet and winding at the time of (0, 30). When the intersection of the spherical rotor 100 and the X axis is the center X, and the intersection of the Y axis is the center Y, the permanent magnet 111 has a region 121 (hereinafter referred to as a center X region) surrounding the center X and a region 122 surrounding the center Y. It is divided into four areas (hereinafter referred to as the center Y area). FIG. 4 shows the arrangement of the permanent magnets 111 in the center Y region 122 as viewed from the Y-axis direction. The permanent magnet 111 is arranged in a ripple shape so that a wave having a magnetic flux density of N and S poles appears around the center Y at every magnetic pole pitch angle λ. One permanent magnet 111 is formed in a columnar shape, and is magnetized on the upper and lower surfaces of the cylinder so as to have N and S poles, or S and N poles. The magnet yoke 110 is preliminarily processed with a rippled hole, and the permanent magnet 111 is fitted into the hole so that the magnet yoke 110 is accurately arranged in a rippled shape. In addition, the magnetic pole pitch angle λ, which is the distance between the peak (N pole) and valley (N pole) of the magnetic flux density, is 11.25 ° (= 360 / 2n, n = 16). If the permanent magnet 111 is arranged on the entire circumference, it can be considered as a rotary motor composed of 32 poles. The permanent magnets 111 arranged in a ripple pattern in this way are arranged in the same manner in the four regions of the center X region 121 and the center Y region 122. On the other hand, the windings 211 are arranged on the inner peripheral side of the winding frame 204 at four locations facing the center X region 121 and the center Y region 122. One winding 211 is composed of three coils of U phase, V phase, and W phase, and the three coils are arranged at intervals of 15 °. The winding 211 configured as described above can generate a rotating magnetic field by passing a three-phase alternating current in a phase matched to the magnetic pole of the permanent magnet. The direction of the rotating magnetic field is such that the winding 211 facing the center X region is in the rotation Ty direction around the Y axis, and the winding 211 facing the center Y region is in the rotation Tx direction around the X axis. The spherical rotor 100 can be rotated by the action of the permanent magnet 111 and the magnetic field. Further, when the spherical rotor 100 is at a position inclined by Ty = 30 ° around the Y axis, the relationship between the permanent magnet 111 in the center Y region 122 and the winding 211 facing it is as shown in FIG. As can be seen from comparison with FIG. 5, the magnetic pole pitch and magnetic pole position of the permanent magnet 111 facing the winding 211 are not changed, and the rotation of the other axis does not change the magnetic pole pitch or magnetic pole position of the own axis. Represents. Therefore, in FIG. 6, by rotating the winding 211 facing the center Y region 122 in the same manner as the three-phase alternating current, the spherical rotor 100 can be rotated around the X axis without torque shortage. When three-phase alternating current is supplied to these windings 211, the magnetic pole position of the permanent magnet 111 is calculated based on the rotation angle (Tx, Ty) detected by the rotary encoder 400, and the current phase matching the magnetic pole is obtained. To energize. Furthermore, drive control in each rotational direction is performed by current control similar to that of a 32-pole rotary motor.

  With such a configuration, the magnetic pole pitch and magnetic pole position of the permanent magnet of its own axis do not change when the other axis of the spherical rotor rotates. As a result, a large amount of rotational motion can be obtained without reducing torque at all. Further, spherical operation can be easily realized by current control similar to that of a conventional rotary motor. Furthermore, feedback control using a rotary encoder can be realized, and the spherical rotor can be operated spherically without step-out.

Next, a method for manufacturing the spherical motor of this embodiment will be described with reference to FIGS. In FIG. 7, legs 202 are assembled to both ends of the base 201 by screwing or the like. Further, the winding unit 5 includes a plurality of windings 211, a plate 6, and an insulating sheet 7 as shown in FIG. 8. The plurality of windings 211 are formed in a concentric spherical shape having a uniform and uniform gap on the outer surface of the spherical rotor 1. The surface of the plate 6 in contact with the plurality of windings 211 is formed in a spherical shape concentric with the plurality of windings 211 with the insulating sheet 7 sandwiched therebetween, and the portion in contact with the winding frame 204 is the winding frame. It is processed into a shape that fits into the groove 8 of 204. The winding unit 5 sandwiches an insulating sheet 7 between plates 6 and adheres along a plurality of windings 211, and then covers the outer surface of the spherical rotor 1 in a spherical shape having a uniform and uniform gap with a resin mold. It is shaped as follows. A plurality of taps are processed in the plate 6, and holes are processed in the winding frame 204 at positions corresponding to the plurality of taps processed in the plate 6.
Next, as shown in FIG. 9, the winding unit 5 is inserted into the winding frame 204 in a state where the winding unit 5 is fixed to the spherical rotor 1 to which the permanent magnet 3 is attached by the magnetic attractive force acting between the permanent magnet 3 and the plate 6. Further, the shaft 101 is inserted into the Tx link 103 and assembled.
As shown in FIG. 10, the assembled Tx link 103 is assembled by pre-assembled legs 202 and a winding frame 204 by screwing or the like.
Next, as shown in FIG. 11, the shaft is inserted into the winding frame 204 and the Tx link 103 via a bearing (not shown). Finally, a shaft is inserted into the Ty link 104 via a bearing (not shown), and the spherical actuator is assembled as shown in FIG.
As shown in FIG. 12, when the winding unit 5 is inserted into the winding frame 204 integrally with the spherical rotor 1, a groove 8 that contacts the winding unit 5 is formed in the winding frame 204. Has been. By doing so, the winding unit 5 is arranged at an accurate position with respect to the spherical rotor 1.

  Next, a second embodiment will be described. FIG. 13 is a perspective view of a spherical motor showing the second embodiment, and FIG. 14 is a cross-sectional view of the vertical ZX plane in FIG. 13 and 14, 150 is a magnet yoke, 151 is a shaft, 152 is a locus of the shaft 151, 153 is a Tx link, 154 is a Ty link, 251 is a base, 500 is a spherical bearing, 501 is a sun ball, and 502 is a bearing leg. , 503 is a planetary sphere. The second embodiment differs from the first embodiment in that a spherical bearing 500 is provided inside the magnet yoke 150 and the Tx link 153 and the Ty link 154 are made thin. The inside of the magnetic yoke 150 is hollowed in a spherical shape, and a spherical bearing 500 is disposed in the hollowed portion. A shaft 151 is attached to the upper part of the magnet yoke, and the lower part is opened so that the bearing legs 502 of the spherical bearing 500 can pass therethrough. The bearing leg 502 has a sun sphere 501 attached to one end and a base 251 attached to the other end. The spherical bearing 500 divides a rolling unit 505 including a planetary ball 503 and a retainer 504 that holds the planetary ball 503 into at least three equal circumferences between the outer peripheral surface of the sun sphere 501 and the inner peripheral surface of the magnetic yoke 150. The spherical rotor 100 is configured to be capable of spherical operation by rolling the planetary ball 503. As described above, the portion of the sun sphere 501 that contacts the spherical bearing 500 has a spherical shape, and the portion that is attached to the bearing leg has a planar shape. Unlike the first embodiment, the spherical bearing 500 supports the weight of the spherical rotor 100 and the load attached to the shaft 151. The rotary bearing 300 is used only for mounting the rotary encoder. Therefore, the Tx link 153 and the Ty link 154 are formed finer than the first embodiment and are significantly reduced in weight. The arrangement of the permanent magnet 111 and the winding 211 is the same as in the first embodiment.

  With such a configuration, the inertia of the link mechanism is greatly reduced, and the spherical rotor can be operated spherically with high angular acceleration.

  In the first and second embodiments, the winding is composed of only the coil. However, the winding may be wound around the iron core. Moreover, although the shape of the permanent magnet is a cylindrical shape, the cross-sectional shape may be an ellipse or a rectangle, and the magnetic pole surface may be an arc or an arc.

The perspective view of the spherical motor which shows Example 1 of this invention. Horizontal XY plane sectional drawing of the spherical motor which shows Example 1 of this invention Vertical ZX plane sectional view of a spherical motor showing Example 1 of the present invention Permanent magnet arrangement diagram of spherical rotor showing Embodiment 1 of the present invention FIG. 5 is a diagram showing the relationship between the permanent magnets and the windings at the rotation angle (0, 0) showing the first embodiment of the present invention. FIG. 9 is a diagram showing the arrangement relationship between permanent magnets and windings when the rotation angle (Tx, Ty) = (30, 0) according to the first embodiment of the present invention. Assembly drawing of legs of spherical motor of embodiment 1 of the present invention Assembly drawing of winding unit of spherical motor of embodiment 1 of the present invention Assembly drawing of Tx link of spherical motor of embodiment 1 of the present invention Assembly drawing of winding unit and legs of spherical motor of embodiment 1 of the present invention Assembly drawing of winding unit and legs of spherical motor of embodiment 1 of the present invention 1 is a top view of a spherical motor according to a first embodiment of the present invention. The perspective view of the spherical motor which shows Example 2 of this invention. Vertical ZX plane sectional view of a spherical motor showing Example 2 of the present invention Perspective view of spherical motor showing prior art

Explanation of symbols

1, 100 Spherical rotor 2, 200 Stator 3, 111 Permanent magnet 4 Electromagnet 5 Winding unit 6 Plate 7 Insulating sheet 8 Groove 101, 151 Shaft 102, 152 Shaft trajectory 103, 153 Tx link 104, 154 Ty link 121 Center X Area 122 Center Y area 201, 251 Base 202 Leg 203 Flange 204 Winding frame 211 Winding 300 Rotary bearing 400 Rotary encoder 401 Rotary scale 402 Detection head 403 Encoder cover 500 Spherical bearing 501 Sun ball 502 Bearing leg 503 Planetary ball 504 Retainer

Claims (4)

In a method of manufacturing a spherical motor comprising a spherical rotor having a plurality of permanent magnets on the surface, and a stator having a plurality of windings arranged via the spherical rotor and a fixed gap,
A method of manufacturing a spherical motor, wherein a winding unit including the winding and the stator is formed, and the winding unit is attached to a winding frame.   12. The method of manufacturing a spherical motor according to claim 11, wherein a groove for mounting the winding unit is formed in the winding frame.   12. The spherical motor according to claim 11, wherein when the winding unit is attached to the winding frame, the spherical unit is mounted in a state where the winding unit is fixed to the spherical rotor by a magnetic attractive force. Method. 12. The method of manufacturing a spherical motor according to claim 11, wherein the inner surface of the winding unit is formed into a spherical shape having a constant and uniform gap on the outer surface of the spherical rotor.

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