JPH08275497A - Linear motor - Google Patents

Abstract

PURPOSE: To detect at least one piece of information on a stator which is to be used for operating a motor easily and accurately and to make the size of the entire structure of the motor by forming a staged section on the surface of a field magnet of the bar-like stator and then locating a sensor for propulsion near and face to face with the staged section. CONSTITUTION: On the surface of a stator 6 which is formed from a straight bar-like member 60, a field magnet for propulsion 61 is installed which is alternately magnetized in N polarity and S polarity. Then, a recess-type staged section 60a is formed in the longitudinal direction of the stator 6. At a bottom face of the staged section 60a, a fine-magnetized section 43b is formed which constitutes a part of an encoder for controlling a velocity of a movable member 7. In a movable member yoke 72, a magnetic sensor 43a which faces the fine- magnetized section 43b is installed with at least a part of it being inserted into the staged section 60a of the stator 6 and thereby the fine-magnetized section 43b and the magnetic sensor 43a are brought near and face to face with each other. By this method, a detection accuracy by the magnetic sensor 43b can be increased and the entire structure can be made small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor, particularly a rod-shaped stator having a field magnet for propulsion, an armature coil fitted on the field magnet, and a magnetic signal wave from the field magnet. The present invention relates to a linear motor equipped with a mover equipped with a propulsion sensor for reading.

[0002]

2. Description of the Related Art A linear motor of this type is disclosed, for example, in Japanese Patent Laid-Open No. 58-36162. JP-A-58
The linear motor taught by Japanese Patent Publication No. 36162 has an N surface.
It is a linear motor including a rod-shaped stator having a propulsion field magnet in which poles and S poles are alternately arranged in a certain direction, and a mover having a cylindrical armature coil fitted onto the stator.

A linear motor of this type in which a mover moves along a rod-shaped stator is disclosed in, for example, Japanese Patent Laid-Open No. 61-916.
Compared with a so-called flat plate type linear motor in which a mover is opposed to a flat plate-like stator as disclosed in Japanese Patent Publication No. 1, it is possible to drive the mover by guiding it to the stator. Since it is not necessary to add guide means for the mover, the structure can be simplified, and it is easy to adjust the positional relationship between the stator and the mover, which is easy to assemble, and the operation accuracy is high. Used in equipment. For example, in an image reading device such as a copying machine or an image scanner, it has been attempted to use it for driving a scanning optical system for a document image.

Also in this type of linear motor in which the mover moves along the rod-shaped stator, in order to continuously drive the mover by applying a constant thrust force to the field magnet of each part of the armature coil. The position is detected, and a current having an appropriate magnitude and direction at that position is applied to each part of the coil. Therefore, the mover is provided with a propulsion sensor such as a Hall element for reading the magnetic signal wave from the field magnet.

Further, in order to obtain the moving distance of the mover, control the moving speed, etc., a fine magnetized portion in which N poles and S poles are alternately arranged at a fine pitch is used as a magnetic scale on the stator. A magnetic sensor consisting of an MR element or the like for reading a magnetic signal from the scale is provided on the mover, or an optical scale is provided in parallel with the stator and an optical sensor for reading the scale information is installed on the mover. There are many things to do.

[0006] Such a propulsion sensor, a magnetic sensor,
The encoder sensor such as an optical sensor is arranged on the outer surface of the armature coil, between the coil parts constituting the armature coil, and outside the armature coil, etc., depending on its characteristics.

[0007]

However, when sensors such as Hall elements and MR elements for detecting magnetic information are provided on the outer surface of the coil, the field on the stator passing through the sensor and the armature coil center is provided. Since the distance to a magnetic information providing portion such as a magnet or a magnetic scale becomes long, the sensitivity of the sensor is deteriorated and the output signal power of the sensors is reduced. Therefore, signal amplification is required. Alternatively, it becomes necessary to increase the amplification factor, and as a result, there is a problem in that it is easily affected by noise.

When the sensors for detecting magnetic information are provided between the coils, the sensitivity can be improved because the sensors can be arranged near the magnetic information providing portion on the stator, but the coils should be spaced apart. Since it is opened and arranged, the motor itself becomes large and complicated. Further, in the case of adopting the optical encoder, if the optical scale is provided outside the stator, the whole structure becomes large and complicated. If an optical scale is provided on the stator to avoid this, the optical sensor must be placed directly and close to the optical scale. Cannot be placed in between,
It is necessary to provide it at a portion considerably deviated from the coil, and then the mover becomes large and complicated.

Further, also in this type of linear motor in which the mover moves along the rod-shaped stator, the positional relationship between the information portion used for motor operation on the stator and the sensors for detecting it is accurately determined. There is also a problem that it takes time and effort to assemble a motor by using it and to install it in a device such as an image reading device. Therefore, the present invention is
Linear including a rod-shaped stator having a propulsion field magnet, an armature coil externally fitted to the field magnet, and a mover having a propulsion sensor for reading a magnetic signal wave from the field magnet. It is a motor, and the sensors for detecting information used for motor operation on the stator can be arranged at a position where the information can be easily and accurately detected, and the overall structure can be made compact and downsized. It is an object of the present invention to provide a linear motor which is easier to assemble than the above motor.

[0010]

In order to solve the above-mentioned problems, the present invention provides a rod-shaped stator having a propulsion field magnet, an armature coil fitted onto the field magnet, and the field magnet. In a linear motor including a mover having a propulsion sensor for reading a magnetic signal wave, a step portion is formed on the surface of the stator in a field magnet portion of the stator, and the propulsion sensor is provided at the step portion. A linear motor (first linear motor) is characterized in that they are arranged close to each other.

In order to solve the above problems, the present invention provides
Linear including a rod-shaped stator having a propulsion field magnet, an armature coil fitted on the field magnet, and a mover having a propulsion sensor for reading a magnetic signal wave from the field magnet. In the motor, at least one step is formed on the surface of the stator, and information providing means for providing position information for motor operation control is provided on the step, and the mover faces the information providing means. There is also provided a linear motor (second linear motor), which is equipped with an encoder sensor which is arranged close to and reads information from the encoder sensor.

In order to solve the above problems, the present invention provides
Linear including a rod-shaped stator having a propulsion field magnet, an armature coil externally fitted to the field magnet, and a mover having a propulsion sensor for reading a magnetic signal wave from the field magnet. In the motor, a step portion is formed on the surface of the stator in the field magnet portion of the stator, and information providing means for providing position information for motor operation control is superimposed on the step portion on the field magnet. The stepping portion is provided with the propulsion sensor in close proximity to each other, and the mover is provided with an encoder sensor in close proximity to the information providing means and reading information from the encoder. Also provided is a linear motor (third linear motor) which is characterized in that

In any of the first, second, and third linear motors according to the present invention, the cross-sectional shape of the stator can be variously circular, rectangular, elliptical, etc. and is not particularly limited. Further, the stepped portion formed on the stator can be said to be a concave portion, and as shown in FIGS. 6A to 6D, a rectangular shape, a triangular shape or a V shape, a semicircle. Shape or U
Various shapes such as a letter-shaped one and a state in which a stator having a circular cross-section is cut into a D-shaped cross-section are conceivable.

Further, in any of the linear motors according to the present invention, the propulsion sensor for reading the magnetic signal wave from the field magnet is not limited thereto, but is typically a magnetoelectric conversion element. One example is a Hall element. The information providing means for providing position information for motor operation control on the stators of the second and third linear motors is typically a magnetic field used to detect the moving speed, moving distance, etc. of the mover. To detect the fine magnetized part in which the N pole and the S pole are alternately arranged in the longitudinal direction of the stator at a fine pitch (for example, 50 μm) to configure the encoder of the system, the home position and the return position of the mover, etc. A magnetizing part or the like partially provided on a straight line in the longitudinal direction of the stator can be cited as a typical example of the encoder sensor on the mover corresponding to these magnetizing parts is an MR element or an MR sensor. There is a current-magnetic effect type magnetic sensor having high sensitivity, which is called. Such a magnetized portion can be obtained by forming a rod-shaped member providing a stator with a material that can be magnetized or further machined, and magnetizing the portion corresponding to the stepped portion provided therein. In addition, a magnetized portion separately formed in a film strip shape, a sheet strip shape, a strip plate shape, or a label shape is joined to the portion corresponding to the stepped portion formed on the rod-shaped member providing the stator by an appropriate means such as an adhesive. You can also get it.

The linear motor of the present invention can employ the magnetic encoder, an optical encoder, or both a magnetic encoder and an optical encoder. When an optical encoder is adopted, as an information providing means for providing position information for motor operation control provided on the stepped portion of the stator in the second and third linear motors, it is typically movable. Used to detect the moving speed and moving distance of the child,
Two kinds of parts with different light reflection states (concave and convex parts with different light reflection states, two kinds of surfaces with different surface roughness so as to have different light reflection states, two kinds of light and dark parts formed by coating the coating, etc. ) Alternately arranged optical scale, a light reflecting portion, etc. partially provided on a straight line in the longitudinal direction of the stator for detecting the home position, the return position, etc. of the mover, As the encoder sensor on the mover corresponding to these optical information providing means,
Typically, a light source and a photocell may be included. Such optical information providing means may be formed directly on the stepped portion of the stator, or may be formed separately in a film strip shape, a sheet strip shape, a strip plate shape, or a label shape, which is formed by an appropriate means such as an adhesive. It can also be obtained by joining to the step portion.

Regardless of the type of the encoder for controlling the motor operation, the linear motor of the present invention has a stepped portion formed on the surface of the stator in the field magnet portion of the stator. The propulsion sensor is arranged close to and facing the step portion, and at least one step portion different from the step portion is formed on the surface of the stator, and position information for motor operation control is formed on the step portion. A linear motor is also conceivable in which information providing means for providing is provided, and the mover is provided with an encoder sensor which is arranged close to the information providing means so as to read information therefrom.

Also in the case of this motor, the information providing means provided on the stepped portion of the stator for providing position information for motor operation control and the corresponding encoder sensor on the mover are of the magnetic type described above. However, an optical type may be used. Further, in any of the linear motors according to the present invention, the stepped portion serves as a mark, which makes it easier to assemble and install in a device than a conventional motor of the same type, but it is easier to assemble a motor and install in a device. Further, at least a part of the stepped portion of the stator may also serve as an engaging portion with a support member that supports the stator so that the stator can be accurately performed.

In this case, the engaging portions are for positioning, for preventing rotation of the stator (for example, in the case of a stator having a circular cross section), or both, depending on the cross-sectional shape of the stator. There are various possible types, and any of these may be used. Further, in any of the linear motors according to the present invention, the step portion of the stator also serves as the guide groove of the mover, and the mover may be provided with a member movable along the step portion. Good. In this way, the assembly accuracy of the motor and the mechanical operation accuracy of the motor are improved accordingly.

In this case, the stepped portion is usually considered to have a concave groove shape, for example, a concave groove shape shown in FIGS. 6A to 6C. Then, it is possible to exemplify a case where a ball spline mechanism is constituted by the groove and the ball on the mover fitted in the groove.

[0020]

In any of the linear motors of the present invention, the armature coil of the mover is energized under the control based on the output of the propulsion sensor that reads the magnetic signal wave from the field magnet. Can be driven along. Further, according to the first linear motor of the present invention, the propulsion sensor for reading the magnetic signal wave from the field magnet is arranged close to and facing the stepped portion on the stator, and according to the second linear motor, the stator is provided. Information providing means for providing position information for motor operation control is provided on the upper step portion, and the encoder sensor on the mover is arranged to face the information providing means so as to face the third linear motor. A propulsion sensor is disposed close to and facing a stepped portion on the stator, and information providing means for providing position information for motor operation control is provided on the stepped portion, and an encoder sensor on the mover provides the information. Since these motors are arranged close to each other, at least one piece of information used for operating the motor on the stator can be easily and accurately detected, and the entire structure is compact. Reduction, can be reduced in size. Further, the motor can be assembled and installed in the device easily and accurately with the stepped portion on the stator as a mark.

Further, when at least a part of the stepped portion of the stator also serves as an engaging portion with a supporting member for supporting the stator, this is utilized to assemble the motor or install it in equipment. Can be performed more easily and accurately. Further, when the stepped portion of the stator also serves as the guide groove of the mover and the movable element is provided with a member movable along the stepped portion,
Motor assembly accuracy and motor mechanical operation accuracy are improved accordingly.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, all linear motors according to the embodiments of the present invention are collectively referred to as LDM. FIG. 1A is a perspective view of an example of a linear motor according to the present invention.
(B) is a sectional view of the motor.

In the linear motor LDM shown in FIG. 1, the mover 7 can reciprocate along a stator 6 formed of a linear rod member 60 having a circular cross section formed of a machinable and magnetizable material. . The stator 6 has a propulsion field magnet 61 formed by alternately magnetizing N-poles and S-poles at a pitch of 60 mm on the surface, and further has a groove having a rectangular cross section extending in the stator longitudinal direction. It is provided with a stepped portion 60a. At the bottom of the step portion 60a, a fine magnetized portion 43b that forms a part of a magnetic encoder 43 (see FIG. 7B) for controlling the speed of the mover 7 is magnetized. The fine magnetized portion 43b has N poles and S poles alternately magnetized at a pitch of 50 μm.

Both ends 63 of the stator 6 are inserted into holes of a stator supporting member in a device such as an image reading device as illustrated in FIG. 5 which will be described later in relation to other motor examples, and the position and posture thereof are set. Be determined and supported. The mover 7 is provided with an armature coil 71 composed of a plurality of ring-shaped coils that are fitted onto the stator 6 with a gap therebetween. The armature coil is supported inside a cylindrical mover yoke 72. There is. Bearings 73 are provided at both ends of the mover yoke 72, and the mover 7 can be guided and moved by the bearings 73 by the stator 73.

Further, the armature coil 71 of the mover 7 has a three-phase ring shape arranged at a position shifted by 2π / 3 in electrical angle (it may be at the same phase as the position shifted by 2π / 3). The coils u, v, and w have a hall element hu, which is a type of magnetoelectric conversion element, as a propulsion sensor for the u-phase coil, and a hall element hv for the v-phase coil.
Similarly, the hall element hw is provided in the w-phase coil so as to face the field magnet 61. Further, the mover yoke 72 is provided with a magnetic sensor (a sensor including a magnetic resistance element called an MR element here) 43a facing the fine magnetized section 43b at the bottom of the stepped portion 60a in a compact arrangement. At least a part of the magnetic sensor 43a is fitted in the step portion 60a and is arranged close to the fine magnetized portion 43b.

Next, another example of the linear motor according to the present invention shown in FIG. 2 will be described. 2A is a cross-sectional view taken along a horizontal plane including the stator longitudinal axis of the motor, and FIG. 2B is a cross-sectional view taken along line YY of FIG. This linear motor LDM is the same as the linear motor shown in FIG. 1, except that in the field magnet 61 portion of the stator 6, the stepped portion 6 in the form of a groove having a rectangular cross section on the surface of the stator.
0a ', and each Hall element hu, hv, hw is arranged so that at least a part thereof fits into the stepped portion, and the fine magnetized portion 43b does not have the stepped portion. The magnetic sensor 43a is opposed to the magnetic sensor 43a. Due to the above-mentioned state, each Hall element is arranged sufficiently close to the field magnet 61 so that magnetic information from it can be reliably detected. The other points are the same as those of the linear motor of FIG. 1, and the same parts as those of the motor of FIG. 1 are designated by the same reference numerals.

FIG. 3 shows a cross section of a stator 6 of a motor according to still another embodiment of the present invention together with sensors facing it. In this linear motor, a step portion 60d is formed on the surface of the stator 6 so as to be cut out in a D shape when viewed in cross section, and a fine magnetized portion 43b is magnetized and formed on the step portion. The field magnet 61 is formed excluding the step portion 60d. The hall elements hu, hv, hw are arranged to face the field magnet 61, and the magnetic sensor 43a is arranged to face the fine magnetized portion 43b and sufficiently close to it. The other points are the same as those of the linear motor shown in FIG.

FIG. 4 shows a cross section of a stator 6 of a motor according to still another embodiment of the present invention, together with sensors facing it. Also in this linear motor, a stepped portion 60d is formed on the surface of the stator 6 so as to be cut out in a D shape when viewed in cross section, and a fine magnetized portion 43b is provided in this stepped portion. However, the field magnet 61 has the step portion 60d.
The fine magnetized portion 43b is formed so as to overlap the field magnet 61. Hall element hu, h
v and hw are arranged so as to face the stepped portion of the field magnet 61 sufficiently, and the magnetic sensor 43a is arranged so as to sufficiently face the fine magnetized portion 43b. The other points are the same as those of the linear motor shown in FIG.

In the linear motor including the stator 6 and the sensors shown in FIGS. 3 and 4, the stepped portion 60d of the stator 6 is used.
Also serves as an engaging portion with a stator support member in a device such as an image reading device. That is, as illustrated in FIG. 5, the stepped portion 60d of the stator 6 is aligned with the straight portion 811 of the hole 81 of the stator support member 8 of the device having a shape similar to the cross-sectional shape of the stator 6. Can be used as an engaging portion for the purpose of preventing the stator 6 from rotating and determining the posture.

Also in the motor shown in FIGS. 1 and 2, the step portions 60a and 60a 'of the stator 6 can be used as such engaging portions. In that case, a hole or a recess for inserting the stator of the stator support member may be formed into a shape that matches the step portion or that the step portion can engage with. When the step portion of the stator 6 also serves as the engaging portion in this manner, motor assembly and installation on a device can be performed easily and accurately.

The shape of the stepped portion in the stator 6 of the linear motor is not limited to that described above, and as shown in FIG. 6, a quadrangular section 60a, a triangular section or a V-shaped section. 60b, semicircular or U-shaped 60
c, a stator having a circular cross section, having a cross-sectional shape cut into a D shape, and the like, such as 60d, may be used. Although not shown, for example, (A) to (C) of FIG.
The stepped portion having a concave groove shape as shown in FIG.
Can also be provided. If this configuration is adopted, the assembly accuracy of the motor and the mechanical operation accuracy of the motor are improved accordingly.

In each of the linear motors LDM, as will be described later, the armature coil 71 of the mover 7 is energized under the control based on the outputs of the hall elements hu, hv, hw to move the mover 7 to the stator. It is possible to drive by being guided by 6. Further, the speed of the mover 7 can be controlled based on the output of the magnetic sensor 43a. The linear motor LDM of FIG.
In the linear motor adopting the stator 6 shown in FIGS. 3 and 4, the finer magnetized portions 43b are provided on the stepped portions 60a and 60d on the stator 6, and the magnetic sensor 43a is arranged sufficiently close to the fine magnetized portions 43b. Therefore, the magnetic sensor can easily and accurately detect the magnetic signal from the fine magnetized portion 43b,
Moreover, since the magnetic sensor 43a is arranged sufficiently close to the step portions 60a and 60d, the entire structure is made compact,
Be miniaturized.

In the linear motor LDM of FIG. 2 and the linear motor employing the stator 6 shown in FIG. 4, the hall elements hu, hv, hw are arranged sufficiently close to the step portions 60a ', 60d on the stator 6. Therefore, the Hall element can easily and accurately detect the magnetic signal from the field magnet 61, and since the Hall element is arranged sufficiently close to the step portions 60a 'and 60d, the whole structure is reduced. Can be made compact and small.

In particular, the stator 6 and the Hall element h shown in FIG.
In the linear motor adopting the arrangement state of u, hv, hw and the magnetic sensor 43a, since the hall elements hu, hv, hw and the magnetic sensor 43a are arranged close to each other facing the step portion 60d, both the magnetic sensor and the hall element are arranged. Magnetic signals can be easily and accurately detected, and the overall structure can be made more compact and compact.

Further, in any of the linear motors LDM, it is possible to assemble the motor and install it in the device easily and accurately with the stepped portions 60a, 60a 'and 60d on the stator 6 as marks. Further, when the stator is flat, it is not possible to distinguish the position of the fine magnetized portion, but when the fine magnetized portion is formed on the step, it is possible to easily identify the position of the fine magnetized portion. You can Therefore, it is possible to prevent the fine magnetization from being destroyed by the tool coming into contact with the fine magnetization portion during assembly. Also, the positioning of the magnetic sensor for detecting the fine magnetization becomes easy.

Next, the operation control of the linear motor LDM will be described. As described above, the field magnet 61 of the stator 6 is magnetized so as to have a distribution of a sinusoidal magnetic flux density with the N pole and the S pole as one cycle. Further, as described above, the armature coil 71 of the mover 7 has an electrical angle of 2π /
Three-phase coils u, v, w arranged at positions shifted by 3 (it may be at the same phase as the position shifted by 2π / 3)
In addition, the mover 7 has a Hall element hu,
hv and hw are provided. In this example, this Hall element detects the magnitude and direction of the magnetic flux of the field magnet 61 at that position. Then, the motor LDM is operated by supplying a current having a magnitude and direction corresponding to the magnitude and direction of the magnetic flux sensed by these Hall elements to the coil.
That is, the so-called three-phase drive system is adopted here,
Signals with a phase difference of 120 degrees are input to the coil, and as a result, a constant thrust is obtained regardless of the position of the mover 7. Further, here, in addition to adopting the three-phase drive method, a phase synchronization control method generally called PLL is adopted in order to drive the mover 7 at a target speed.

FIG. 7 (A) is a schematic block diagram of an electric circuit for controlling the operation of the motor LDM, and FIG. 7 (B) shows the main part of the operation control circuit including the speed control circuit of the phase synchronization control system. In FIGS. 7A and 7B, 41 is a DC power supply, 42 is an energization control circuit unit including the Hall element and the like, 43 is an encoder for detecting the moving speed of the mover 7, and The magnetic sensor 43a is included. Reference numeral 44 is a speed control unit based on the phase synchronization control method.
The encoder 43 is a magnetic sensor 43a on the mover 7.
Is a magnetic encoder that reads the magnetism of the fine magnetized portion 43b on the stator 6.

In FIG. 7B, reference numeral 45 is a microcomputer for instructing a predetermined operation of the motor LDM for image reading and outputting a reference clock signal to the phase synchronization control section 49, and 46 is an input / output of the computer 45. Port, 47 is amplifier, 48 is switching unit, 49
Is a phase synchronization controller, 50 is a compensation circuit, and 51 is an amplifier circuit.

According to the control circuit shown in FIG. 7, the reference clock signal corresponding to the target speed is input from the computer 45 to the phase synchronization control section 49, and the moving speed signal of the mover 7 is sent from the encoder 43 to the control section. Feedback is input to 49. The phase synchronization control unit 49 outputs a signal according to the difference between the frequency and the phase of the pulse of the reference clock and the pulse of the feedback signal from the encoder 43,
The compensation circuit 50 compensates the lead / lag of the transmission system, and uses the output voltage as the reference input voltage of the Hall element. As described above, the Hall element outputs a voltage corresponding to the magnitude and direction of the magnetic flux at a certain position, but the output voltage has a characteristic proportional to the reference input voltage. Therefore, the output voltage corresponding to the difference between the reference clock signal and the feedback signal is output from the Hall element. The output voltage from the Hall element is proportionally amplified by the amplifier circuit 51 and is supplied to the armature coil. As described above, the motor LDM is operated so that the frequency and phase of the pulse of the reference clock and the pulse of the feedback signal are matched, that is, the target speed of the mover 7 is matched.

The present invention is not limited to the above-mentioned embodiment. For example, if there is no problem, means for guiding the traveling of the mover 7 may be provided separately from the stator 6.

[0041]

As described above, according to the present invention,
Linear including a rod-shaped stator having a propulsion field magnet, an armature coil externally fitted to the field magnet, and a mover having a propulsion sensor for reading a magnetic signal wave from the field magnet. It is a motor, and the sensors for detecting information used for motor operation on the stator can be arranged at a position where the information can be easily and accurately detected, and the overall structure can be made compact and downsized. It is possible to provide a linear motor which is easier to assemble than the above motor.

When at least a part of the stepped portion formed on the linear motor stator also serves as an engaging portion with a support member for supporting the stator, this is utilized to perform motor assembly or equipment. Can be installed more easily and accurately. When the step portion formed on the linear motor stator also serves as the guide groove of the mover and the mover is provided with a member movable along the step portion, the motor assembly accuracy,
The mechanical operation accuracy of the motor is improved accordingly.

[Brief description of drawings]

FIG. 1A is a perspective view of an example of a linear motor according to the present invention, and FIG. 1B is a sectional view taken along a horizontal plane including a longitudinal axis of a stator of the motor.

FIG. 2A is a cross-sectional view taken along a horizontal plane including a stator longitudinal axis of another example of the linear motor according to the present invention, and FIG. 2B is a view of the motor. 3 is a cross-sectional view taken along line YY of FIG.

FIG. 3 is a diagram showing a cross section of a stator in still another motor according to the present invention together with sensors facing it.

FIG. 4 is a view showing a cross section of a stator in still another motor according to the present invention together with sensors facing it.

FIG. 5 is an explanatory view showing a state where the motor stator shown in FIGS. 3 and 4 is mounted on a stator support member in a device in which the motor is installed.

6 (A) to 6 (D) are views showing examples of the shape of the step portion of the stator in the linear motor of the present invention.

FIG. 7 (A) is a block diagram showing an outline of an operation control circuit of a linear motor according to the present invention, and FIG. 7 (B) shows a main part of an operation control circuit including a speed control circuit of a phase synchronization control system. FIG.

[Explanation of symbols]

6 Stator 60 Rod-shaped member 61 Propulsion field magnet 60a, 60a ', 60b, 60c, 60d Stator 6
Upper step part 63 End part of the stator 6 Mover 71 Armature coil 72 Mover yoke 73 Bearings hu, hv, hw Hall element 43a Magnetic sensor 43b Fine magnetizing part 43 Encoder

Claims (5)

[Claims] 1. A mover equipped with a rod-shaped stator having a propulsion field magnet, an armature coil fitted onto the field magnet, and a propulsion sensor for reading a magnetic signal wave from the field magnet. A linear motor having a field magnet portion of the stator, wherein a step portion is formed on a surface of the stator, and the propulsion sensor is arranged to face and approach the step portion. . 2. A mover equipped with a rod-shaped stator having a propulsion field magnet, an armature coil fitted onto the field magnet, and a propulsion sensor for reading a magnetic signal wave from the field magnet. In the linear motor provided with, at least one step portion is formed on the surface of the stator, information providing means for providing position information for motor operation control is provided at the step portion, and the mover is provided with A linear motor comprising an encoder sensor which is arranged close to the information providing means so as to read information from the information providing means. 3. A mover having a rod-shaped stator having a propulsion field magnet, an armature coil externally fitted to the field magnet, and a propulsion sensor for reading a magnetic signal wave from the field magnet. And a step portion is formed on the surface of the stator in the field magnet portion of the stator, and the information providing means for providing position information for motor operation control to the step portion is the field magnet. For an encoder that is provided so as to be superimposed on a magnet, the propulsion sensor is arranged to face the step portion, and the movable element is arranged to face the information providing means to read information from the movable element. A linear motor that is equipped with a sensor. 4. The linear motor according to claim 1, wherein at least a part of the stepped portion of the stator also serves as an engaging portion with a support member that supports the stator. 5. The stepped portion of the stator also serves as a guide groove of the mover, and the movable element is provided with a member movable along the stepped portion. Linear motor.