JP2015186327A - Motor, manufacturing method of the same, and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which achieves high torque and low cogging torque, and to provide a manufacturing method of the motor and a robot.SOLUTION: A motor includes: a rotary shaft 3; and a cylindrical magnet assembly 52 fixed to the rotary shaft 3. Individual magnet pieces 54 are joined to each other by an adhesive to form the magnet assembly 52. The magnet assembly 52 is positioned by using a cylindrical surface 58 as a reference surface to be joined.

Description

  The present invention relates to a motor, a motor manufacturing method, and a robot.

For small motors, a multipolar structure has been proposed to achieve both high torque and low cogging torque. However, high assembly accuracy is required for multi-pole motors. To achieve stable quality in mass production, not only high processing accuracy is required for each part,
Even during assembly, precise system management is essential.

A general inner rotor type motor is composed of a cylindrical rotor on which pieces of permanent magnets are attached in the circumferential direction and a stator on which a coil is wound. For example, a structure is disclosed in which a divided cylindrical magnet is pressed against and fixed to a rotating shaft with a flanged yoke portion by an intermediate ring (see, for example, Patent Document 1).

JP 9-56093 A

However, in the structure of Patent Document 1, unless the processing accuracy of the members to be assembled is ensured with high accuracy, there is a risk of increasing the cogging torque and shortening the life of the bearing.

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 motor according to this application example includes a rotating shaft and a cylindrical magnet assembly fixed to the rotating shaft, and the magnet assembly includes a plurality of magnets. The individual pieces are joined to each other with an adhesive, and the magnet assembly is joined with its position adjusted using a cylindrical surface as a reference surface.

According to this application example, the outer diameter of the magnet assembly in which the magnet pieces are arranged in the circumferential direction of the rotor and the coaxiality of the rotor can be maintained. Thereby, high torque and low cogging torque can be realized.

Application Example 2 A motor manufacturing method according to this application example is a motor manufacturing method including a rotating shaft and a cylindrical magnet assembly fixed to the rotating shaft. The step of adjusting the position of the individual pieces with the cylindrical surface as a reference surface and joining them with an adhesive forms a rotor having the magnet assembly.

According to this application example, since the magnet pieces are assembled on the basis of the reference surface, which is a cylindrical surface, the outer diameter of the magnet assembly is determined by the accuracy of the cylindrical surface. A cutting process after magnetization is not required. As a result, the coaxiality between the outer diameter and the rotor can be maintained without going through a difficult cutting process, and a motor that realizes high torque and low cogging torque can be stably manufactured.

Application Example 3 In the motor manufacturing method described in the application example, a cylindrical jig having the same cylindrical inner surface as the reference surface is used.

According to this application example, the reference surface can be easily set by using the cylindrical surface of the cylindrical jig as the reference surface.

Application Example 4 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 magnet assembly which concerns on this embodiment, and its assembly jig, (A) is the top view which looked at the assembly jig from the cover side, (B) is the lower layer structure figure of the broken-line part of (A) (C) is AA sectional drawing of (A). Sectional drawing of the state which inserted the rotating shaft in the cylindrical jig | tool which concerns on this embodiment. The block diagram which showed the procedure which assembles the rotor which concerns on this embodiment, (A) is the figure which inserts an inner cylinder in a cylindrical jig | tool, (B) is the figure which inserts the piece of a permanent magnet in a cylindrical jig | tool, (C) is a figure which covers a cylindrical jig and is filled with an adhesive. The block diagram which showed the procedure which assembles the rotor which concerns on this embodiment. (A) is a figure which inserts a rotating shaft in a cylindrical jig | tool, (B) is a figure which covers a lid | cover on a cylindrical jig | tool. 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.

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.

(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,
A stator (armature) 4 and a rotor 5 are provided. 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 magnet assembly 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 magnet assembly 52 has an annular column shape. The magnet assembly 52 has a multipolar structure in which a plurality of magnetic poles are formed in the circumferential direction. The magnet assembly 52 is formed by joining a plurality of pieces 54 of permanent magnets with an adhesive (see FIG. 2B). The magnet assembly 52 is joined with its position adjusted using the cylindrical surface 58 as a reference surface (see FIG. 2C).

FIG. 2 is a view for explaining the magnet assembly 52 and its assembly jig 64 according to the present embodiment. (A) is the top view which looked at the assembly jig 64 from the lid | cover 66 side, (B) is the broken-line part 68 of (A).
(C) is an AA cross-sectional view of (A). FIG. 2 shows a state where the magnet assembly 52 is assembled in the assembly jig 64. The magnet assembly 52 has eight permanent magnet pieces 54 arranged in the circumferential direction, and an inner cylinder 70 is bonded to the inner diameter thereof (see FIG. 4B). The assembly jig 64 includes a cylindrical jig 62, a lid 66, and a ring 90. The cylindrical jig 62 is made of a magnetic material that can attract a permanent magnet.

The magnet assembly 52 is joined with its position adjusted using the cylindrical surface 58 as a reference surface. A cylindrical jig 62 having the same cylindrical inner surface as the reference surface is used as the reference surface. According to this, the reference plane can be easily set by using the cylindrical surface 58 of the cylindrical jig 62 as the reference plane.

First, the fitting of the magnet assembly 52 and the assembly jig 64 will be described with reference to the cross-sectional view of FIG. The cylindrical jig 62 includes a shaft fitting surface 92 which is a bearing fitting portion of the rotary shaft 3 which will be described later, an inner cylinder fitting surface 94 which is an outer diameter of the inner cylinder 70, and individual pieces of permanent magnets. 54, a permanent magnet piece fitting surface 96 that is a surface to be fitted to the outer diameter, and the coaxiality of the other two fitting surfaces 94, 96 is maintained with reference to the shaft fitting surface 92. It is processed to sag.

The material of the cylindrical jig 62 is iron as an example of a representative magnetic material, but other magnetic materials do not impair the effect of the present embodiment. The inner cylinder 70 fitted to the inner diameter of the permanent magnet piece 54 is:
It is made of a non-magnetic metal (for example, brass), and has a thickness that does not buckle in the inner diameter direction due to the attractive force between the adjacent permanent magnet pieces 54. For example, when a neodymium magnet is used as the permanent magnet piece 54, an attractive force of 0.1 N / mm ² acts on the adjacent permanent magnet pieces 54. On the other hand, when brass having an inner diameter of 20 mm and a wall thickness of 0.5 mm is used for the inner cylinder 70, the buckling stress of the inner cylinder 70 is 3.6 N / mm 2, and the magnet assembly of this embodiment is 36 times stronger. A body 52 can be formed. However, since a nonmagnetic metal is used for the inner cylinder 70, the inner cylinder 70 acts as a gap between the rotating shaft 3 and the permanent magnet piece 54 to be bonded thereafter, and the magnet is thick when the thickness is thick. Harmful to circuits. In order to exhibit the effect of the present embodiment and not deteriorate the performance as the motor 1, the inner cylinder 70 has a thickness of about 0.5 to 1 mm, or the outer diameter width of the permanent magnet piece 54 in the circumferential direction. Is preferably less than 10%.

Further, a ring 90 is provided on the surface where the permanent magnet piece 54 and the cylindrical jig 62 abut. This is to prevent adhesion between the cylindrical jig 62 and the magnet assembly 52 when the adhesive is filled between the inner cylinder 70 and the permanent magnet pieces 54, and is separated from the adhesive. The ring 90 is made of a resin having good properties.

The top view shown in FIG. 2A is a view of the assembly jig 64 from the lid 66 side, and is provided with a through hole 88 for injecting an adhesive and a through hole 89 for screwing. The lid 66 is made of a nonmagnetic metal, and is provided with a shaft fitting surface 92 and an inner cylinder fitting surface 94 in the same manner as the cylindrical jig 62. The reason why the lid 66 is made of a non-magnetic metal is to prevent the permanent magnet pieces 54 from being detached from the cylindrical jig 62 by an attractive force, and to maintain the coaxiality between the rotary shaft 3 and the inner cylinder 70. Only this lid 66 is used. FIG. 2B shows a lower layer structure in the broken line portion 68 shown in the top view shown in FIG. 2A, and the adhesive injection hole 98 has two pieces 54 of permanent magnets adjacent to each other. The inner cylinder 70 is provided at a position where it can be expected, and an adhesive can be injected from the through hole 88.

FIG. 3 is a cross-sectional view showing a state where the rotating shaft 3 is inserted into the cylindrical jig 62 according to the present embodiment. The rotating shaft 3 is fitted on a shaft fitting surface 92 between the lid 66 and the cylindrical jig 62. The rotating shaft 3 and the magnet assembly 52 are coated with an adhesive in advance on the outer peripheral surface of the core 51 in contact with the inner cylinder 70, and the rotating shaft 3 is attached to the cylindrical jig 62.
Is inserted and a cylindrical jig 62 is covered with a lid 66 to be bonded.

4 and 5 are configuration diagrams showing a procedure for assembling the rotor 5 according to the present embodiment.
4A is a diagram of inserting the inner cylinder 70 into the cylindrical jig 62, FIG. 4B is a diagram of inserting the permanent magnet pieces 54 into the cylindrical jig 62, and FIG. 4C is a cylinder. FIG. 5A is a diagram of inserting the rotating shaft 3 into the cylindrical jig 62, and FIG. 5B is a lid of the cylindrical jig 62. FIG. Hereinafter, the assembly procedure of the rotor 5 according to the present embodiment will be described with reference to the drawings.

First, as a first step, as shown in FIG. 4A, the inner cylinder 70 is inserted into the cylindrical jig 62.

Next, as a second step, as shown in FIG. 4B, permanent magnet pieces 54 are inserted between the inner cylinder 70 and the cylindrical jig 62. Here, the permanent magnet pieces 54 are inserted in order from 1 to 8 so that the adjacent permanent magnet pieces 54 have opposite polarities.

Next, as a third step, as shown in FIG. 4 (C), a cylindrical jig 62 is covered with a lid 66,
The adhesive injection hole 98 (through the through hole 88 is attached so that the permanent magnet piece 54 and the inner cylinder 70 are bonded.
Adhesive is injected into FIG. 2 (B). In the case of an adhesive that cures at room temperature, the adhesive is left with the lid 66 attached until the adhesive is fixed. In the case of a heat-curing adhesive, the temperature is kept constant until the adhesive is fixed with the lid 66 attached. Leave in the tank.

Next, when the adhesive is completely fixed, as a fourth step, the cover 66 is removed from the cylindrical jig 62 and the adhesive is applied to the core 51 as shown in FIG. 3 is inserted into the cylindrical jig 62.

Next, as a fifth step, as shown in FIG.
The cylindrical jig 62 is covered with a lid 66 so that the coaxiality is maintained, and is left until the adhesive is fixed.

By assembling the rotor 5 according to the above procedure, the rotor 5 without eccentricity can be assembled.

In this embodiment, the cylindrical assembly 62 of the magnetic assembly jig 64 fitted to the outer diameter of the permanent magnet piece 54 and the inner diameter of the permanent magnet piece 54 are fitted into the magnet assembly 52 by bonding. The ring-shaped magnet assembly 52 is formed in advance using the inner cylinder 70 integrated with the inner cylinder 70. Here, the effect of using the magnetic cylindrical jig 62 is the attraction force between the permanent magnet pieces 54 and the cylindrical jig 62, and the outer diameter of the magnet assembly 52 is naturally the accuracy of the cylindrical jig 62. This is because it is guaranteed by Further, by fitting the inner cylinder 70 to the inner diameter of the permanent magnet piece 54, the permanent magnet piece 54 is prevented from being detached from the cylindrical jig 62 by the attractive force acting between the permanent magnet pieces 54. be able to. In the present embodiment, the magnet assembly 52 and the rotating shaft 3 are connected to each other while the outer diameter of the magnet assembly 52 and the coaxiality of the bearing fitting portion of the rotating shaft 3 are maintained by the assembly jig 64 described above. Because of the bonding, the rotor 5 without eccentricity can be made.

(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.

According to the present embodiment, the outer diameter of the magnet assembly 52 in which the permanent magnet pieces 54 are arranged in the circumferential direction of the rotor 5 and the coaxiality of the rotor 5 can be maintained. Thereby, high torque and low cogging torque can be realized.

As described above, the motor, the motor manufacturing method, and the robot have been described based on the illustrated embodiments. However, the present invention is not limited to this, and the configuration of each unit is an arbitrary configuration having the same function. Can be substituted. In addition, any other component may be added to the present invention.

DESCRIPTION OF SYMBOLS 1 ... Motor 7, 8 ... Robot 2 ... Housing 3 ... Rotating shaft 4 ... Stator 5 ... Rotor 21, 22 ... Bearing 41 ... Coil 51 ... Core 52 ... Magnet assembly
54 ... Permanent magnet pieces (magnet pieces) 58 ... Cylindrical surface 62 ... Cylindrical jig 64 ... Assembly jig 66 ... Lid 68 ... Dashed portion 70 ... Inner cylinder 71 ... Base 72 ... First arm 73 ... Second
Arm 74 ... Working head 75 ... End effector 81 ... Base 82, 83, 84
85 ... Arm 86 ... List 88, 89 ... Through-hole 90 ... Ring 92 ... Shaft fitting surface 94 ... Inner cylinder fitting surface 96 ... Individual magnet fitting surface 98 ... Adhesive injection hole 741 ...
Spline nut 742 ... Ball screw nut 743 ... Spline shaft 861 ...
Support ring 862 ... Wrist body.

Claims (4)

A motor comprising a rotating shaft and a cylindrical magnet assembly fixed to the rotating shaft,
The magnet assembly is formed by joining a plurality of magnet pieces with an adhesive,
The motor is characterized in that the magnet assembly is joined by adjusting its position with a cylindrical surface as a reference surface. A method of manufacturing a motor comprising a rotating shaft and a cylindrical magnet assembly fixed to the rotating shaft,
A method for manufacturing a motor, comprising: adjusting a position of a plurality of magnet pieces with a cylindrical surface as a reference surface, and joining the same with an adhesive to form a rotor having the magnet assembly. In the manufacturing method of the motor according to claim 2,
A motor manufacturing method using a cylindrical jig having the same cylindrical inner surface as the reference surface.   A robot comprising the motor according to claim 1.

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