JP2000014115A - Action detector for rotating/direct-acting combined motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit high accuracy positioning by receiving at a fixed position, an operating signal of a motor output shaft fitted to direct-acting bearings which allow synchronous rotation and axial-direction movement of the output shaft, and detecting the action of the output shaft. SOLUTION: If a rotor 7 rotates at positions corresponding to a row of current flowing coils 3-5, direct-acting bearings and a signal generating unit 24 rotate synchronously along with a motor output shaft 8. If the signal generating unit 24 generates a rotation signal of the rotor output shaft 8, a signal detector 25 receives the rotation signal, and rotational position information of the motor output shaft 8 is obtained by the signal generating unit 24. Since the signal generating unit 24 and a signal detector 25 constitute a rotational position detector (optical encoder) 20 for the motor output shaft 8 and it is fitted to a direct-acting bearing 23 and set, it is possible to obtain precise rotational position information of the motor output shaft 8, and to perform high- precision positioning control of the rotational position of the motor output shaft 8 by the rotational position information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation detecting device for a combined rotary / linear motion motor for detecting an operating position of an output shaft of a combined rotary / linear motion motor capable of performing both rotation and axial movement. It is about.

[0002]

2. Description of the Related Art For example, in an automatic assembling machine for automatically assembling parts in a factory, an end effector unit for supplying and assembling parts may require both a rotary operation and a linear (linear) operation. is there. In this case, conventionally, both the rotation and the linear motion are realized by a device in which a plurality of motors and a transmission mechanism are combined. However, such a device is complicated and large in size. In order to simplify and reduce the size, the rotation and
A combined rotary / linear motion motor capable of performing both linear motions is already known.

FIG. 5 is a cross-sectional view showing a conventional rotary / linear motion combined motor disclosed in, for example, Japanese Patent Application Laid-Open No. 4-359657. FIG. 6 is a perspective view partially showing a coil row in FIG. FIG. 7 is a perspective view showing the rotor in FIG. In the figure, reference numeral 1 denotes a stator, and 2 denotes a cylindrical motor case which also serves as a yoke of the stator 1. The motor case 2 is arranged in a vertical axis, and has, for example, three coil arrays 3 on its inner peripheral surface. To 5 are fixedly arranged at predetermined intervals in the axial direction (vertical direction). Each of the coil arrays 3 to 5 includes three stator coils (not shown) arranged at intervals of, for example, 120 degrees along the circumferential direction of the motor case 2.

Reference numeral 6 denotes bearings mounted on both upper and lower ends of the motor case 2. A shaft (motor output shaft) 8 of a rotor 7 is supported on the bearing 6 so as to be rotatable and movable in the axial direction. . Reference numeral 9 denotes a rotor yoke fitted and fixed to the shaft 8; Are configured.

[0005] Reference numerals 11 to 13 denote Hall elements for detecting the rotational position of the rotor provided at the center of each of the stator coils constituting each of the coil arrays 3 to 5, and 14 to 16 denote predetermined elements of the coil arrays 3 to 5. A reflection-type photosensor provided on the stator coil for detecting a reference rotation position of the rotor, a mirror 17 provided at a predetermined portion of the rotor yoke 9, and the mirror 17 facing the photosensors 14 to 16, 14 to 16 are turned on in response to the reflected light from the mirror 17, and the reference rotation position of the rotor 7 is detected by the on operation.

Next, the operation will be described. FIG.
This is a state in which a current is supplied to the middle coil row 4 in the row of coil rows. When the current is switched to, for example, the upper coil row 3 in this state, the magnetic force generated in the supplied upper coil row 3 causes The rotor 7 located at the middle position is sucked, and the shaft 8 moves upward in the axial direction together with the rotor 7, and stops at the position where the magnetic resistance becomes minimum.

As described above, the coil array to be energized is switched, and the rotor 7 moves axially (linearly) in the direction of the energized coil array, so that the height of the end of the shaft 8 of the rotor 7 becomes higher. , Three stages corresponding to the energizing coil arrays 3 to 5, upper, middle, and lower, and the rotor 7 rotates at the changed position.

In the above, the rotational position of the rotor 7 after the axial movement is detected by the Hall elements 11 to 13, the mirror 17, and the photo sensors 14 to 16. In this case, the magnetic pole detection positions by the Hall elements 11 to 13 and the signals necessary for the reference rotation position detection by the photosensors 14 to 16 are output from the motor, and the rotation of the rotor 7 (shaft 8) is performed. Therefore, the Hall elements 11 to 13, the photosensors 14 to 16, and the mirror 17 constitute an operation detection device of a combined rotary / linear motion motor for detecting the rotational position of the rotor 7.

[0009]

Since the conventional operation detecting device for a combined rotary / linear motion motor is constructed as described above, the Hall elements 11 to 13 and the photo sensors 14 to 1 are used.
6, the signals necessary for detecting the magnetic pole position of the rotor 7 and detecting the reference rotational position are output from the motor, and based on the output signals, the rotational position of the rotor 7 (the end of the shaft 8) is detected. However, in order to perform the positioning more accurately, there is a problem that the output signal has insufficient resolution and the positioning accuracy in the rotor rotation direction is not good. For example, when the number of stator coils constituting each of the coil arrays 3 to 5 is three as described above, the magnetic poles (S and N) of the rotor are considered to be one pole pair, and the rotor The voltage change generated in the Hall element by the magnetic flux is one cycle of a pseudo sine wave per one rotation of the rotor, and the reference rotation position detection signal by the photo sensor is also one pulse per one rotation of the rotor. Therefore, it is considered impossible to obtain rotational position information having a resolution of about 1/100 rotation, for example. On the other hand, in the field of automatic assembling machines where the application of a combined rotary / linear motion motor is expected, 1/1000 to 1000
Since a positioning resolution of about 1 / 10,000 revolutions is required, there is a problem that the above-mentioned conventional operation detecting device for a combined rotary / linear motion motor cannot cope with this. In addition, the above-described conventional operation detecting device for a combined rotary / linear motion type motor only performs position detection in the rotor rotational direction by a Hall element and a photo sensor, and has position detecting means in the rotor linear motion direction. Therefore, there has been a problem that accurate position detection and positioning control in the direction of linear movement of the rotor cannot be performed. Furthermore, the Hall elements 11 to 11 for each of the coil arrays 3 to 5
13 and a plurality of photosensors 14 to 16 and a mirror 17, there are problems such as a large number of parts, a complicated configuration, and high cost.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and can obtain accurate operating position information of a motor output shaft, and can position the operating position of the motor output shaft with high accuracy. Rotation and rotation that can be performed and reduce the number of parts to achieve downsizing and cost reduction
It is an object of the present invention to obtain an operation detection device for a combined linear motor.

In addition, the present invention enables the rotation and linear motion of the motor output shaft to be performed smoothly, thereby obtaining more accurate operating position information of the motor output shaft. It is an object of the present invention to obtain a composite motor operation detection device.

Further, according to the present invention, it is possible to obtain accurate rotation operation information of the motor output shaft, and it is possible to accurately and accurately determine the rotation position of the motor output shaft based on the rotation operation information. An object of the present invention is to obtain a motion detection device for a dynamic composite motor.

Further, according to the present invention, accurate linear motion information of the motor output shaft can be obtained, and the linear motion position of the motor output shaft can be positioned with high accuracy based on the linear motion information. An object of the present invention is to obtain an operation detection device for a combined rotary / linear motion motor.

[0014]

An operation detecting device for a combined rotary / linear motion motor according to the present invention comprises a plurality of coil arrays arranged in an axial direction, and these coil arrays are selectively energized. A motor output shaft having a stator and a motor output shaft rotatably and axially movably supported with a polarized magnetized rotor. A linear bearing that is attached to at least one end of the shaft so as to be able to rotate synchronously and allows axial movement of the motor output shaft; and a rotary bearing that rotatably supports the motor output shaft via the linear bearing. A signal generator provided on the linear motion bearing for generating an operation signal of the motor output shaft, and a signal detector for receiving a signal from the signal generator at a fixed position and detecting the operation of the motor output shaft. With That.

[0015] In the motion detecting device for a combined rotary / linear motion motor according to the present invention, the stator includes a plurality of linear motion coil rows arranged in the axial direction and a rotary stator coil arranged in the circumferential direction. The rotor includes a first rotor that is polarized and magnetized in the axial direction and corresponds to the linear motion coil array, and a second rotor that is magnetized in the circumferential direction and corresponds to the rotation stator coil. .

In the operation detecting device for a combined rotary / linear motion motor according to the present invention, the signal generation section is provided at a rotating portion of the linear motion bearing so as to be synchronously rotatable, and generates a rotation signal of a motor output shaft. And a signal detector comprising a rotation position signal detector that receives a signal from the rotation signal generator and detects rotation of the motor output shaft.

In the motion detecting device for a combined rotary / linear motion motor according to the present invention, the signal generator is provided at a linear motion portion movable in the axial direction of the linear motion bearing, and an axial movement signal of the motor output shaft is provided. Wherein the signal detector comprises a linear motion position signal detector which receives a signal from the linear motion signal generator and detects an axial movement position of the motor output shaft. It is.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a cross-sectional view showing an operation detecting device for a combined rotary / linear motion motor according to Embodiment 1 of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part of FIG. 1, which is the same as or equivalent to FIGS. Portions are given the same reference numerals, and redundant description is omitted. In the drawing, reference numeral 21 denotes a bearing case connected to the lower part of a motor case 2 having a closed cylindrical shape;
Denotes two upper and lower rotary bearings mounted on a bearing case 21, 23 denotes a linear motion bearing mounted on the rotary bearing 22, and this linear motion bearing 23 has a ball 23c on a spline of an inner race 23a and an outer race 23b. The inner race 23a is fitted to the lower end of the motor output shaft 8 and the outer race 23b is connected to the rotary bearing 22.
It is rotatably mounted and supported.

Accordingly, the linear motion bearing 23 is configured to rotate synchronously with the motor output shaft 8 and to allow the motor output shaft 8 to move in the axial direction (linear motion). The upper end of the motor output shaft 8 is rotatably and axially movable by a rotating bearing 6 on the upper part of the motor case 2 as in the conventional case.

Reference numeral 24 denotes a signal generator provided on the outer race 23b of the linear motion bearing 23.
The motor output shaft 8 rotates in synchronism with the motor output shaft 8 to generate an operation signal. In the first embodiment, the motor output shaft 8 includes an encoder plate of an optical encoder that generates a rotation signal of the motor output shaft 8. Reference numeral 25 denotes a signal detector attached and fixed inside the bearing case 21.
The operation of the motor output shaft 8 is detected by receiving a signal from the signal generating unit 24 at a fixed position. In the first embodiment, a light emitting unit and a light receiving unit for detecting rotation of the motor output shaft 8 are provided. Consists of

Accordingly, in the first embodiment, the signal generator 24 and the signal detector 25 constitute a rotational position detector (optical encoder) 20 for the motor output shaft 8, and this rotational position detector 20 is assembled and set on a linear motion bearing 23.

Next, the operation will be described. When any one of the coil arrays 3 to 5 of the stator 1 is energized, the rotor 7 rotates at a position corresponding to the energized coil array. At this time, the linear motion bearing 23 and the signal generator 24 rotate synchronously with the motor output shaft 8, and the signal generator 24 generates a rotation signal of the motor output shaft 8, and the signal detector 25 receives the rotation signal. I do. Therefore, the rotation position information of the motor output shaft 8 can be obtained by the signal generation unit 24 and the signal detector 25, and the rotation position of the motor output shaft 8 can be controlled with high accuracy by the rotation position information. It becomes possible.

In the first embodiment, the linear motion bearing 23 having the ball spline structure has been described. However, this linear motion bearing 23 is different from the outer race 23b in that, for example, the inner race 23a such as a spline shaft is used. Any configuration is possible as long as it is movable in the axial direction and engages in the direction around the axis. Further, the rotational position detector 20 is not limited to an optical encoder, but may be another magnetic encoder, a potentiometer, or the like.

According to the first embodiment described above, the signal generating section 24 is provided on the linear bearing 23 for supporting the motor output shaft 8 rotatably with respect to the rotary bearing 22 and movably in the axial direction.
Is provided so that the signal from the signal generator 24 is received by the signal detector 25 at a fixed position to detect the rotation of the motor output shaft 8, so that the signal generator 24 and the signal detector 25 By using the rotational position detector 20, accurate rotational position information of the motor output shaft 8 can be obtained, and the rotational position of the motor output shaft 8 can be controlled with high accuracy by using the rotational position information. This has the effect. In addition, since the rotary bearing 22, the linear motion bearing 23, and the signal generator 24 are combined and integrated, and one signal detector 25 is arranged at a position corresponding to the signal generator 24, the configuration is shown in FIGS. As in the prior art, each coil row 3-5
There is no need to provide the Hall elements 11 to 13 or the plurality of photosensors 14 to 16 for each case. Therefore, the number of parts is reduced, and the size and cost can be reduced.

Embodiment 2 FIG. 3 is a sectional view showing an operation detection device for a combined rotary / linear motion motor according to Embodiment 2 of the present invention. The same or corresponding parts as those in FIGS. 1, 2 and FIGS. And duplicate explanations are omitted. In FIG. 3, reference numeral 1a denotes a linear motion stator, and a plurality of linear motion stators 1a are arranged in an axial direction in a motor case 2 which also serves as a yoke (FIG. 3).
(3 rows). Reference numeral 7a denotes a linear rotor (first rotor) fitted and fixed to the motor output shaft 8, and a rotor yoke 9a of the linear rotor 7a.
Is polarized in the axial direction by the permanent magnet 10a.

Reference numeral 1b denotes a rotary stator arranged and fixed on the inner peripheral surface of the motor case 2 separately from the linear stator 1a, and 7b is fitted and fixed to the motor output shaft 8 so as to correspond to the rotary stator 1b. The rotating yoke 9b of the rotating rotor 7b is polarized in the circumferential direction by a permanent magnet 10b.

That is, in the second embodiment, the stator 1 and the rotor 7 in the first embodiment are replaced with a stator 1a and a rotor 7a dedicated to linear motion, and separately provided with the stator 1b and the rotor 7b dedicated to rotation. The configuration is such that the rotary motion and the linear motion of the output shaft 8 are respectively performed by different rotors, and the other configuration is the same as that of the first embodiment.

Therefore, according to the second embodiment, the rotational motion and the linear motion of the motor output shaft 8 can be smoothly performed with good responsiveness. There is an effect that accurate rotational position information can be obtained, and the rotational position of the motor output shaft 8 can be positioned and controlled with higher accuracy.

Embodiment 3 FIG. 4 is a sectional view showing an operation detecting device for a combined rotary / linear motion motor according to Embodiment 3 of the present invention. The same or corresponding parts as those in FIGS. 1 to 3 and FIGS. And duplicate explanations are omitted. In the third embodiment, the outer race 23b of the linear motion bearing 23 is fixed to the bearing case 21, and the inner race 23a of the linear motion bearing 23 supports the lower end of the motor output shaft 8 via the rotary bearing 22, The inner race 23a of the linear motion bearing 23 is formed so as to extend in the axial direction longer than the outer race 23b. The detector 25a is fixed to the bearing case 21.

Therefore, the signal generator 24a according to the third embodiment moves synchronously with the motor output shaft 8 via the inner race 23a of the rotary bearing 22 and the linear motion bearing 23 when the motor output shaft 8 moves in the axial direction. Thus, a linear motion signal generator for generating a linear motion signal of the motor output shaft 8 is provided. The signal detector 25a receives the linear motion signal of the motor output shaft 8 from the signal generator 24a, and And a linear motion position signal detector for detecting the linear motion position.

In the third embodiment as well, the linear motion bearing 23 is configured such that the inner race 23a such as a ball spline or a spline shaft can move in the axial direction with respect to the outer race 23b and engage in the direction around the axis. And the linear motion position detector 20
The present invention is not limited to the optical encoder, but may be other types such as a magnetic encoder and a potentiometer.

According to the third embodiment described above, the motor output shaft 8 is rotatably and axially supported by the linear motion bearing 23 via the rotary bearing 22, and the linear motion of the linear motion bearing 23 A signal generator 24a is provided at the moving part (the inner race 23a), and a signal from the signal generator 24a is received by the signal detector 25a at a fixed position to detect the direct movement of the motor output shaft 8. The linear motion position detector 20 including the signal generator 24a and the signal detector 25a can obtain accurate linear motion position information of the motor output shaft 8, and the linear motion position information allows the motor output shaft 8 to be obtained.
There is an effect that it is possible to perform positioning control of the direct-moving position with high accuracy. The rotating bearing 22 and the linear bearing 2
3 and the signal generating unit 24a are combined and integrated, and the signal generating unit 2
4A, one signal detector 25a is arranged at the corresponding position. Therefore, as in the related art shown in FIGS. 5 to 7, hall elements 11 to 13 are provided for each coil row 3 to 5, or a plurality of There is no need to provide the photosensors 14 to 16, so that the number of components is reduced, and there is an effect that downsizing and cost reduction can be achieved.

In the first embodiment and the second embodiment, the signal detector 20 comprises a rotation position detector for detecting the rotation of the motor output shaft 8, and in the third embodiment, the signal detector 20 comprises Although the description has been given of the case where the linear movement position detector 20 detects the linear movement of the motor output shaft 8, both the rotation position detector and the linear movement position detector are provided in a single linear bearing 23 in a unitized state. It is also possible. In this case, for example, in the linear motion bearing 23 shown in FIGS. 1 and 2, the inner race 23a is extended longer than the outer race 23b as shown in FIG. Is provided with a linear motion signal generator 24a, and
The linear motion signal detector 25a paired with the linear motion signal generator 24a
While the outer race 2 of the linear bearing 23 is
3b shows the rotation signal generator 2 as in the case of FIGS.
By providing the rotation signal generator 24 and the rotation signal detector 24 paired with the rotation signal generator 24, both rotation and linear movement of the motor output shaft 8 can be detected.

[0034]

As described above, according to the present invention, the signal generating section is provided on the linear motion bearing for supporting the motor output shaft so as to be rotatable and axially movable with respect to the rotary bearing. , And the operation of the motor output shaft is detected by receiving the signal from the fixed position signal detector, so that the signal generator and the signal detector obtain accurate rotational position information of the motor output shaft. With this rotation position information, the rotation position of the motor output shaft can be controlled with high accuracy. Also,
A rotary bearing, a linear motion bearing, and a signal generation unit can be combined and integrated, so that it is necessary to provide a Hall element for each coil row or provide a plurality of photosensors as in the related art. And the number of parts is reduced,
There is an effect that size reduction and cost reduction can be achieved.

According to the present invention, a stator is constituted by a plurality of direct-acting coil rows arranged in the axial direction and a rotating stator coil arranged in the circumferential direction, and is polarized and magnetized in the axial direction. The first corresponding to the linear motion coil row
Since the rotor and the second rotor magnetized in the circumferential direction and corresponding to the stator coil for rotation are provided, the rotational motion and the linear motion of the motor output shaft are smoothly and responsively performed by different rotors. Therefore, more accurate rotational position information of the motor output shaft can be obtained, and the rotational position of the motor output shaft can be controlled with higher accuracy.

According to the present invention, a rotation signal generating section for generating a rotation signal of the motor output shaft is provided at a rotating portion of the linear motion bearing, and a signal from the rotation signal generating section is received by the rotation position signal detector to output the motor output. Since the rotation of the shaft is detected, accurate rotation position information of the motor output shaft can be obtained by the rotation signal generator and the rotation position signal detector. There is an effect that it is possible to control the rotational position of the shaft with high accuracy. In addition, since the rotation signal generation unit, the linear motion bearing, and the rotation bearing can be combined and integrated, the number of parts is reduced as compared with the conventional Hall element or photo sensor, and miniaturization and cost reduction are achieved. There is an effect that it can be achieved.

According to the present invention, a linear motion signal generating section for generating a rotation signal of the motor output shaft is provided at a linear motion portion of the linear motion bearing, and a signal from the linear motion signal generating section is detected by the linear motion position signal detector. Receiving and detecting the linear motion of the motor output shaft, it is possible to obtain accurate linear motion position information of the motor output shaft by the linear motion signal generator and the linear motion position signal detector, This linear movement position information has an effect that the linear movement position of the motor output shaft can be controlled with high accuracy. Further, since the linear motion signal generating section, the linear motion bearing, and the rotary bearing can be combined and integrated, the number of components is reduced as compared with the conventional Hall element or photo sensor, and the size and cost are reduced. There is an effect that can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an operation detection device for a combined rotary / linear motion motor according to Embodiment 1 of the present invention;

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a cross-sectional view illustrating an operation detection device for a combined rotary / linear motion motor according to Embodiment 2 of the present invention;

FIG. 4 is a sectional view showing an operation detection device for a combined rotary / linear motion motor according to Embodiment 3 of the present invention;

FIG. 5 is a cross-sectional view showing a conventional rotary / linear motion combined motor.

FIG. 6 is a perspective view partially showing a coil array in FIG. 5;

FIG. 7 is a perspective view showing the rotor in FIG. 5;

[Explanation of symbols]

REFERENCE SIGNS LIST 1 stator, 1a direct-drive stator, 1b rotary stator, 3 to 5 coil rows, 7 rotors, 7a direct-drive rotor (first rotor), 7b rotary rotor (second rotor), 8 motor output shaft, 22 rotary bearings , 23 linear motion bearing, 24 signal generator (rotation signal generator), 24a
Signal generator (linear motion signal generator), 25 signal detector (rotation signal position detector), 25a signal detector (linear motion signal position detector).

Claims (4)

[Claims] 1. A motor comprising: a plurality of coil arrays arranged in an axial direction; a coil to which these coil arrays are selectively energized; and a rotatable and axially rotatable rotor having a polarized magnetized rotor. An operation detection device for a combined rotary / linear motion motor having a motor output shaft movably supported, the motor output shaft being attached to at least one end of the motor output shaft so as to be synchronously rotatable, and having an axial direction of the motor output shaft. A linear bearing that allows movement, a rotary bearing that rotatably supports the motor output shaft via the linear bearing, and a signal generator that is provided in the linear bearing and emits an operation signal of the motor output shaft. ,
A signal detector for receiving the signal from the signal generator at a fixed position and detecting the operation of the motor output shaft. 2. The stator comprises a plurality of direct-acting coil rows arranged in the axial direction and a rotating stator coil arranged in the circumferential direction, and the rotor is polarized and magnetized in the axial direction to form the linear motor. A first rotor corresponding to the moving coil array, and a second rotor corresponding to the rotating stator coil magnetized in the circumferential direction.
2. The operation detecting device for a combined rotary / linear motion motor according to claim 1, further comprising a rotor. 3. A signal generator comprising: a rotation signal generator which is provided at a rotating portion of the linear motion bearing so as to be able to rotate synchronously and emits a rotation signal of a motor output shaft; and a signal detector is provided by the rotation signal generator. 2. The operation detecting device for a combined rotary / linear motion motor according to claim 1, further comprising a rotation position signal detector for detecting rotation of said motor output shaft in response to said signal. 4. The signal generator includes a linear motion signal generator that is provided at a linearly movable portion of the linear motion bearing that is movable in the axial direction and that generates an axial movement signal of the motor output shaft.
2. The combined rotary / linear motion type according to claim 1, further comprising a linear motion position signal detector that receives a signal from said linear motion signal generation unit and detects an axial movement position of said motor output shaft. Motor operation detection device.