JP2015186325A - rotor, motor, and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor where a permanent magnet is difficult to peel off.SOLUTION: A rotor of this invention is a rotor 5 including a divided cylindrical magnet 52 fixed to a rotary shaft 3, where mold material 57 is formed at an end part of the magnet 52 intersecting a rotation axis of the rotary shaft 3.

Description

  The present invention relates to a rotor, a motor, and a robot.

In industrial robots, small motors are used everywhere, and the performance of the motor greatly affects the robot's performance. In robots, a motor that achieves a small and large torque is required, and a powerful permanent magnet represented by a neodymium magnet is used for the rotor.

In a small motor, a permanent magnet is attached to a rotating shaft made of soft magnetic material. FIG.
As shown in FIG. 2, a plurality of permanent magnets 52 are attached to the rotating shaft 3 of the rotor (rotor), and the outer diameter of the permanent magnet 52 corresponds to the auxiliary ring 70 in order to prevent the permanent magnet 52 from peeling off. It is attached. In order to realize a stronger torque in a small motor, it is necessary to bring the permanent magnet 52 of the rotor close to the magnetic pole surface of the opposing stator (not shown) as much as possible.

For example, the structure of the protection member which covers the magnet surface of the outer cylindrical surface of a rotor is disclosed (for example, refer patent document 1).

JP 2009-239988 A

However, in the structure using the conventional auxiliary ring 70, the auxiliary ring 70 is added to the outer diameter of the permanent magnet 52.
Therefore, the permanent magnet 52 and the magnetic pole of the stator must be separated by the thickness of the auxiliary ring 70, and there is a risk that a reduction in torque is inevitable. Further, in the structure of Patent Document 1, the rotor and the stator are excessively separated by the thickness of the protective member, which may reduce the efficiency.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

Application Example 1 A rotor according to this application example is a rotor in which a divided cylindrical magnet is fixed to a rotating shaft, and a molding material is provided at an end of the magnet that intersects the rotating shaft of the rotating shaft. It is formed.

According to this application example, a stepped portion is provided at both ends of the permanent magnet in the rotation axis direction of the rotor, and the stepped portion is fixed with resin, thereby providing a rotor in which the permanent magnet is hardly peeled off.

Application Example 2 In the rotor according to the application example described above, the magnet has a stepped portion at an end that intersects the rotation axis of the rotating shaft, and the outer diameter of the molding material formed in the stepped portion The outer diameters of the magnets other than the stepped portions are substantially the same.

  According to this application example, the outer diameter of the rotor can be made uniform.

Application Example 3 In the rotor according to the application example described above, the magnet has an engagement portion on a surface facing the rotation shaft, and the rotation shaft has the engagement portion on a surface facing the magnet. It has the non-engagement part to fit.

According to this application example, the plurality of permanent magnets attached to the rotor can be arranged at equal intervals in the circumferential direction.

Application Example 4 In the rotor according to the application example described above, the engagement portion is a trapezoidal protrusion, and the non-engagement portion is a V-shaped groove.

  According to this application example, the permanent magnet and the rotary shaft can be easily fitted.

Application Example 5 A motor according to this application example includes the rotor according to any one of the above.

According to this application example, by using the rotor described in any one of the above items, the permanent magnet is difficult to be peeled off, so that the stability and safety of the motor can be improved.

Application Example 6 A robot according to this application example includes the motor described above.

  According to this application example, it is possible to provide a robot having an effect by the motor described above.

Sectional drawing which shows the motor which concerns on this embodiment. The figure for demonstrating the structure of the permanent magnet which concerns on this embodiment, (A) is the figure of the permanent magnet seen from the outer diameter side, (B) is the figure of the permanent magnet seen from the inner diameter side. The figure for demonstrating the structure of the rotor which concerns on this embodiment, (A) is the schematic of a rotating shaft, (B) is the schematic of the state which attached the permanent magnet to the rotating shaft, (C) is resin in a level | step-difference part FIG. The figure for demonstrating the assembly procedure of the rotor which concerns on this embodiment, (A) is the process of introducing a rotating shaft into an assembly jig, (B) is the process of inserting a permanent magnet in an assembly jig, (C) is The process of filling the gap with resin. The flowchart for demonstrating the assembly procedure of the rotor which concerns on this embodiment. The perspective view which shows the robot to which the motor which concerns on this embodiment is applied. The perspective view which shows the robot to which the motor which concerns on this embodiment is applied. The figure for demonstrating the rotor provided with the conventional permanent magnet.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings. Note that the drawings to be used are appropriately enlarged or reduced so that the part to be described can be recognized.

(First embodiment)
(motor)
FIG. 1 is a cross-sectional view showing a motor according to this embodiment.
As shown in FIG. 1, the motor 1 according to the present embodiment includes a housing (exterior case) 2,
It has a stator (stator) 4 and a rotor (rotor) 5. The motor 1 is not particularly limited, and examples thereof include a servo motor and a stepping motor.

Bearings 21 and 22 are provided on the upper wall and the bottom wall of the housing 2. The shafts 21 and 22 are rotatably supported by the rotary shaft 3. Alternatively, the core 51 is fixed to the rotary shaft 3 in the housing 2. The rotor 5 has a cylindrical shape, and includes a rotating shaft 3, a core 51 made of a soft magnetic material such as iron, and a permanent magnet 52 provided on the outer periphery of the core 51. A stator 4 is disposed around the rotor 5. The stator 4 has a cylindrical shape and has a plurality of coils 41 arranged at predetermined intervals in the circumferential direction.

The permanent magnet 52 has an annular column shape. The permanent magnet 52 has a multipolar structure in which a plurality of magnetic poles are formed in the circumferential direction.

FIG. 2 is a view for explaining the structure of the permanent magnet 52 according to the present embodiment. FIG. 2 (A)
FIG. 7 is a view as seen from the outer diameter side of the permanent magnet 52, and FIG. 9B is a view as seen from the inner diameter side of the permanent magnet 52.
The permanent magnet 52 is formed by powder sintering.

As shown in FIG. 2, the permanent magnet 52 of the present embodiment has step portions 54 provided at both ends in the rotation axis direction on a surface 53 facing the core (not shown) of the stator 4, and the opposite rotation shaft. 3
The opposing surface 55 is provided with a trapezoidal protrusion (engagement portion) 56 linearly in the rotation axis direction. In the present embodiment, the trapezoidal protrusion 56 will be described as an example. However, as long as the positioning function is achieved, even a semicircular protrusion does not change the effect. The permanent magnet 52 includes a plurality of fan-shaped permanent magnets 5.
2 are arranged in a disk shape. In the present embodiment, the permanent magnet 52 has a central angle (degree) α = 60 degrees, and the six permanent magnets 52 are arranged in a disk shape. Each permanent magnet 52
The direction of the magnetic flux is the thickness direction in the disk shape, in other words, the normal direction of the side surface.

FIG. 3 is a view for explaining the configuration of the rotor 5 according to the present embodiment. (A) is a schematic view of the rotating shaft 3, (B) is a schematic view of a state in which the permanent magnet 52 is attached to the rotating shaft 3, and (C) is a step (54) filled with resin (mold material) 57. It is the schematic of the state which carried out.
As shown in FIG. 3A, the rotary shaft 3 of the present embodiment is provided with a V-shaped groove (non-engaging portion) 58 that serves as a guide when the permanent magnet 52 is fitted. This V-shaped groove 58
May be formed by a rolling method or may be formed by cutting. The permanent magnets 52 are evenly arranged in the circumferential direction by being assembled so that the V-shaped grooves 58 and the trapezoidal protrusions 56 of the permanent magnets 52 are fitted. According to this, the several permanent magnet 52 attached to the rotor 5 can be arranged at equal intervals in the circumferential direction. Moreover, the permanent magnet 52 and the rotating shaft 3 can be easily fitted.

And the step part 54 formed in the rotating shaft direction both ends of the permanent magnet 52 is filled with resin 57, and the outer diameter of the filled resin 57 and the outer diameter of the permanent magnet 52 are assembled by an assembly jig 59 described later. Are molded so that they are substantially the same. In other words, the resin 5 formed on the step portion 54.
7 and the outer diameter of the permanent magnet 52 other than the stepped portion 54 are substantially the same. According to this,
The outer diameter of the rotor 5 can be made uniform.

Here, the resin 57 covers the stepped portion 54 of the permanent magnet 52 in the circumferential direction, so that the permanent magnet 52 is covered.
Can be prevented from coming off from the rotating shaft 3. However, the resin 57 covering the stepped portion 54 is used.
If it is thin, the problem of insufficient filling and insufficient strength will occur.
Also in the resin 57 reinforced with 60, a thickness of at least about 0.5 mm is required. Further, since the length of the permanent magnet 52 not covered with the resin 57 in the rotation axis direction is an effective permanent magnet 52 length that affects the torque of the motor 1, the rotation of the core of the stator 4 facing the permanent magnet 52 is rotated. It is necessary to roughly match the axial length.

A convex portion or a concave portion may be provided on the surface of the stepped portion 54 of the permanent magnet 52 that contacts the resin 57. According to this, it is possible to prevent the resin 57 from shifting from the stepped portion 54 of the permanent magnet 52 toward the end portion.

The molding material 57 may be made of a resin reinforced with fibers (filler 60). As the resin constituting the molding material 57, for example, a resin reinforced with glass fiber is advantageously used. In particular, the resin is appropriately selected from such resins in consideration of strength, thin-wall formability, and the like.
As an example, LCP (liquid crystal polymer), PA (polyamide) polymer alloy and the like are suitable. Examples of the resin reinforced with fibers include glass fiber reinforced resin and carbon fiber reinforced resin.

The molding material 57 may be made of a resin reinforced with particles (filler). Particles that are one component constituting the molding material 57 are not particularly limited, but preferred examples include silicates such as wollastonite, sericite, kaolin, clay, mica, talc, montmorillonite, silica, alumina , Metal oxides such as magnesium oxide, zirconium oxide and titanium oxide, carbonates such as calcium carbonate, magnesium carbonate and dolomite, sulfates such as calcium sulfate, magnesium sulfate and barium sulfate, glass beads, glass flakes, boron nitride, carbonized Silicon, silicon nitride, potassium titanate, etc.
These may be hollow (for example, glass microballoons, shirasu balloons,
Carbon balloon). According to this, the resin composition reinforced with particles is excellent in the balance of heat resistance, rigidity and impact resistance, and gives a molded product with small anisotropy.

In the present embodiment, by fixing both ends of the permanent magnet 52 in the rotation axis direction with the resin 57, it is possible to realize a structure that prevents the permanent magnet 52 from being peeled without breaking the easily damaged permanent magnet 52.

FIG. 4 is a view for explaining an assembling procedure of the rotor 5 according to the present embodiment. (A) shows the step of introducing the rotating shaft 3 into the assembly jig 59, (B) shows the step of inserting the permanent magnet 52 into the assembly jig 59, and (C) fills the gap 61 with the resin 57. The process is shown.
The rotor 5 of the present embodiment can be assembled by positioning the rotary shaft 3 and the permanent magnet 52 using the assembly jig 59 and filling the gap 61 between the assembly jig 59 and the rotor 5 with the resin 57. .

FIG. 4A shows a configuration of an assembly jig 59 for inserting the rotating shaft 3 and the permanent magnet 52. The assembly jig 59 includes a cylinder 62 and a lower lid 63. Both the cylinder 62 and the lower lid 63 are made of metal, but a release agent is applied to the surface filled with the resin 57 so that the resin 57 to be filled later is not fixed to the assembly jig 59. Here, the cylinder 62 is formed with an inner diameter that fits the outer diameter of the permanent magnet 52 so that the resin 57 does not flow into the outer peripheral surface of the permanent magnet 52 excluding the stepped portion 54. On the other hand, the lower lid 63 is in contact with the bottom surface in the rotational axis direction of the stepped portion 54 of the permanent magnet 52, and a groove 64 for releasing the filled resin 57 is formed on the surface in contact with the cylinder 62. The cylinder 62 and the lower lid 63 are assembled so as to ensure coaxiality, and are fastened with screws 65.

FIG. 4B is a diagram illustrating a state where the rotating shaft 3 and the permanent magnet 52 magnetized are inserted into the assembly jig 59 assembled in FIG. The rotary shaft 3 is fitted into the surface where the bearing is fitted later and the hole 66 of the lower lid 63, the permanent magnet 52 is fitted into the inner diameter of the cylinder 62, and the surface of the lower lid 63 and the stepped portion 54 of the permanent magnet 52 are brought into contact with each other. It is pushed in until it touches. Here, the permanent magnets 52 are sequentially inserted from 1 to 6 so that the adjacent permanent magnets 52 have opposite polarities.

FIG. 4C is a diagram for explaining a state in which the upper lid 67 is covered and the resin 57 is filled.
Is fastened by a cylinder 62 and a screw 68 in a state where it is fitted to the surface of the rotary shaft 3 on which the bearing fits and the outer diameter of the cylinder 62. Thus, the lower lid 63, the cylinder 62, the upper lid 67 and the rotating shaft 3
By fitting the permanent magnet 52, the coaxiality of the manufactured rotor 5 is guaranteed.

The resin 57 is injected from the gate 69 of the upper lid 67, passes between the V-shaped groove 58 and the permanent magnet 52, and is filled on the lower lid 63 side. Here, both end faces of the rotation shaft 3 in the rotation axis direction,
The structure of the rotor 5 in which the permanent magnet 52 is not detached from the rotating shaft 3 is realized by covering the both surfaces of the permanent magnet 52 in the rotation axis direction, the outer peripheral surface of the stepped portion 54 of the permanent magnet 52, and the three surfaces with the resin 57. be able to.

Resin 57 to be filled in accordance with the operating temperature of the motor 1 in order to exert the effect of this embodiment.
Is preferably selected. This is because the permanent magnet 52 is demagnetized by heat.
When the heat generation of the motor 1 is less than 100 ° C., the resin 57 having no heat resistance that can be cured at room temperature may be used. When the heat generation of the motor 1 reaches 150 ° C., it is necessary to select the resin 57 that is heat resistant and molded by heating. is there. And when using the resin 57 shape | molded by heating, it is necessary to devise the material of a cylinder in order to prevent demagnetization. When the heat generation of the motor 1 is less than 100 ° C., a general two-component epoxy resin that cures at room temperature is preferable. Since molding is performed at room temperature, the permanent magnet 52 does not demagnetize and the cylinder 62 is non-magnetic. A metal may be used. On the other hand, when the heat generation of the motor 1 reaches 150 ° C., an unsaturated polyester resin 57 excellent in heat resistance is preferable, and it is necessary to heat and mold to 130 ° C. to 150 ° C. In this case, a magnetic material such as iron is used for the cylinder 62 so that the same magnetic circuit of the motor 1 is formed around the rotor 5 so as not to cause demagnetization due to heat during molding. When a magnetic circuit is not made, irreversible demagnetization occurs from around 100 ° C. However, demagnetization can be prevented even at 130 ° C. or higher by making a magnetic circuit and increasing the permeance coefficient of the permanent magnet 52.

FIG. 5 is a flowchart for explaining an assembly procedure of the rotor 5 according to the present embodiment. In the assembly jig 59 described with reference to FIG. 4, it is assumed that the cylinder 62, the lower lid 63, and the upper lid 67 are assembled in a molding machine (not shown) at the stage of FIG.

First, in step S10, the procedure for assembly is different between when heating and molding the resin 57, and when not heating. If not, the process moves to step S16. If heating is required, the process moves to step S12.

Next, in step S12, the assembly jig 59 and the resin 57 are heated to appropriate temperatures.
A molding machine (not shown) is provided with a heater and a temperature sensor.

Next, in step S14, it is determined whether the heating temperature has reached the target temperature, and the assembly jig 5
When 9 and the resin 57 can be heated to a predetermined temperature, the process proceeds to step S16. When the assembly jig 59 and the resin 57 cannot be heated to a predetermined temperature, the process returns to step S12.

Next, in Step S16 and Step S18, the rotating shaft 3 and the permanent magnet 52 are used.
Is inserted into the assembly jig 59. According to the description of FIG. 4 described above, the rotating shaft 3 and the permanent magnet 52 are mechanically inserted into the assembly jig 59 until they contact each other.

Next, in step S20, the upper lid 67 is covered and the assembly jig 59 is heated until the temperature of the assembly jig 59 is stabilized at a temperature suitable for molding. Once you have heated to the appropriate temperature, step S
Move to 22.

  Next, in step S22, the assembly jig 59 is filled with the resin 57.

Next, in step S24, the filled resin 57 is held at a predetermined temperature so as to be completely cured (curing process). When the resin 57 is cured, the process proceeds to step S26.

  Next, the rotor 5 is taken out from the assembly jig 59 in step S26.

Next, in step S28, the resin 57 is deburred. This completes the assembly of the rotor 5 of the present embodiment.

By using the assembly procedure of the present embodiment described above, both ends of the permanent magnet 52 in the rotation axis direction are fixed with the resin 57, and the rotor 5 prevents the permanent magnet 52 from peeling without breaking the easily damaged permanent magnet 52. Can be realized.

According to the present embodiment, the stepped portion 54 is provided at both ends of the permanent magnet 52 in the rotation axis direction of the rotor 5, and the stepped portion 54 is fixed with the resin 57, thereby providing the rotor 5 in which the permanent magnet 52 is hardly peeled off.

Moreover, since the permanent magnet 52 is difficult to peel off by using the rotor 5, the stability and safety of the motor 1 can be improved.

(robot)
FIG. 6 is a perspective view showing a robot 7 to which the motor 1 according to this embodiment is applied.
Next, a robot to which the motor 1 described above is applied will be described. As examples of the robot, a horizontal articulated robot and a vertical articulated robot are shown below, but the robot is not limited to these, and may be a double-armed robot or other other-axis robot.
The robot 7 according to the present embodiment is a horizontal articulated robot as shown in FIG. Such a robot 7 includes a base 71, a first arm 72, a second arm 73, and a work head 7.
4 and an end effector 75.

The base 71 is fixed to a floor surface (not shown) with bolts or the like, for example. A first arm 72 is connected to the upper end of the base 71. The first arm 72 is rotatable around a rotation axis along the vertical direction with respect to the base 71. In the base 71, a motor 1 (1A) for rotating the first arm 72 is installed.
A second arm 73 is connected to the tip of the first arm 72. The second arm 73 is a first arm
The arm 72 is rotatable about a rotation axis along the vertical direction. Second arm 7
3, a motor 1 (1B) that rotates the second arm 73 is installed.

A work head 74 is disposed at the tip of the second arm 73. The working head 74 includes a spline nut 741 and a ball screw nut 742 that are coaxially disposed at the tip of the second arm 73, and a spline shaft 743 inserted through the spline nut 741 and the ball screw nut 742. The spline shaft 743 can rotate about its axis with respect to the second arm 73 and can move (elevate) in the vertical direction.

In the second arm 73, a motor 1 (1C) and a motor 1 (1D) are arranged. The driving force of the motor 1C is generated by a spline nut 74 by a driving force transmission mechanism (not shown).
1 and when the spline nut 741 rotates forward and backward, the spline shaft 743 rotates forward and backward around the shaft along the vertical direction. On the other hand, the driving force of the motor 1D is transmitted to the ball screw nut 742 by a driving force transmission mechanism (not shown).
Is rotated forward and reverse, the spline shaft 743 moves up and down.

An end effector 75 is connected to the tip (lower end) of the spline shaft 743. The end effector 75 is not particularly limited, and examples thereof include one that grips the object to be conveyed and one that processes the object to be processed. According to this, the robot 7 which has the effect by the motor 1 as described above can be provided.

FIG. 7 is a perspective view showing a robot 8 to which the motor 1 according to this embodiment is applied.
As shown in FIG. 7, the robot 8 according to the present embodiment is a vertical articulated (six axis) robot. Such a robot 8 includes a base 81, four arms 82, 83, 84, 85, and a wrist 86, which are sequentially connected.

The base 81 is fixed to a floor surface (not shown) with bolts or the like, for example. The arm 82 is connected to the upper end portion of the base 81 in a posture inclined with respect to the horizontal direction, and the arm 82 can rotate about a rotation axis along the vertical direction with respect to the base 81. It has become. In addition, a motor 1 (1E) for rotating the arm 82 is installed in the base 81.
An arm 83 is connected to the distal end portion of the arm 82, and the arm 83 is rotatable about a rotation axis along the horizontal direction with respect to the arm 82. In the arm 83, a motor 1 (1F) that rotates the arm 83 with respect to the arm 82 is provided.

An arm 84 is connected to the tip of the arm 83, and the arm 84 can rotate about a rotation axis along the horizontal direction with respect to the arm 83. Further, in the arm 84, a motor 1 (1G) that rotates the arm 84 with respect to the arm 83 is installed.
An arm 85 is connected to the distal end portion of the arm 84, and the arm 85 can be rotated around a rotation axis along the central axis of the arm 84 with respect to the arm 84. Also, arm 85
Inside, a motor 1 (1H) for rotating the arm 85 relative to the arm 84 is installed.

A wrist 86 is connected to the tip of the arm 85. The wrist 86 includes a ring-shaped support ring 861 connected to the arm 85, and a cylindrical wrist body 862 supported at the tip of the support ring 861. The front end surface of the wrist body 862 is a flat surface, and is, for example, a mounting surface on which a manipulator that holds a precision device such as a wristwatch is mounted.

The support ring 861 can be rotated around a rotation axis along the horizontal direction with respect to the arm 85. The wrist main body 862 is rotatable about a rotation axis along the central axis of the wrist main body 862 with respect to the support ring 861. In the arm 85, a motor 1 (1I) for rotating the support ring 861 relative to the arm 85 and a motor 1 (1J) for rotating the wrist body 862 relative to the support ring 861 are disposed. Yes. Motor 1I
, 1J is transmitted to the support ring 861 and the wrist body 862 by a driving force transmission mechanism (not shown). According to this, the robot 8 which has the effect by the motor 1 as described above can be provided.

In addition, embodiment is not limited above, It can also implement with the following forms.
(Modification)
In the first embodiment described above, the molding material 57 is not limited to resin, and may be composed of, for example, an adhesive. As the adhesive, an acrylic adhesive, an epoxy adhesive, or the like may be used.

As described above, the rotor, the motor, and the robot have been described based on the illustrated embodiment, but the present invention is not limited to this, and the configuration of each part is an arbitrary configuration having the same function. Can be replaced. In addition, any other component may be added to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Motor 7, 8 ... Robot 2 ... Housing 3 ... Rotation shaft (rotation axis) 4
... Stator (stator) 5 ... Rotor (rotor) 21, 22 ... Bearing 41 ... Coil
51 ... Core 52 ... Permanent magnet (magnet) 53, 55 ... Surface 54 ... Stepped portion 56 ... Projection (
(Engagement part) 57 ... resin (mold material) 58 ... groove part (non-engagement part) 59 ... assembly jig 60
... filler (fiber or particle) 61 ... gap 62 ... cylinder 63 ... lower lid 64 ... groove 65
, 68 ... Screw 66 ... Hole 67 ... Top cover 69 ... Gate 71 ... Base 72 ... First arm
73 ... Second arm 74 ... Working head 75 ... End effector 81 ... Base 82,
83, 84, 85 ... arm 86 ... wrist 741 ... spline nut 742 ... ball screw nut 743 ... spline shaft 861 ... support ring 862 ... wrist body.

Claims (6)

A divided cylindrical magnet is a rotor fixed to a rotating shaft,
A rotor characterized in that a molding material is formed at an end of the magnet that intersects the rotation axis of the rotation shaft. The rotor according to claim 1,
The magnet has a stepped portion at an end that intersects the rotation axis of the rotating shaft,
The rotor according to claim 1, wherein an outer diameter of the molding material formed on the step portion and an outer diameter of a magnet other than the step portion are substantially the same. The rotor according to claim 1 or 2,
The magnet has an engaging portion on a surface facing the rotating shaft,
The rotary shaft has a non-engaging portion that fits with the engaging portion on a surface facing the magnet. In the rotor as described in any one of Claims 1-3,
The engaging portion is a trapezoidal protrusion.
The non-engaging part is a V-shaped groove part.   A motor comprising the rotor according to claim 1.   A robot comprising the motor according to claim 5.

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