JP2016041013A - Actuator with linear motion guide mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator with a linear motion guide mechanism in which a sensor for detecting a rotating position of a shaft can be provided at an end portion of a housing in an axial line direction, and a scale can be prevented from being prolonged equal to or more than a stroke of the shaft.SOLUTION: A hollow end portion 10c-2 of a rotor 4, in an axial line direction, supported by bearings 14a and 14b is projected from the inside of a housing 2 to the outside in the axial line direction from the bearings 14a and 14b. A rotating position of the end portion 10c-2 of the rotor 4 projected from the bearings 14a and 14b can be detected by a sensor 27 provided in the housing 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an actuator with a linear motion guide mechanism that guides a shaft so as to be linearly movable and rotates the shaft around an axis.

  For example, on the head axis of a chip mounter that mounts electronic components on a substrate, a linear / rotary compound actuator (in other words, Z) that moves the suction pad in the Z-axis direction and rotates the suction pad in the θ direction around the Z-axis.・ Theta actuator is incorporated. By moving the suction pad in the Z-axis direction, an electronic component can be placed on the surface of the substrate, and by rotating the suction pad in the θ direction, the rotational position of the electronic component can be positioned. . This type of linear / rotary combined actuator is widely used not only for chip mounters but also for robots that move a moving body in the Z-axis direction and rotate it in the θ direction.

  The combined linear / rotary actuator is configured by combining a linear motor that linearly moves a shaft and a rotary motor that rotates the shaft so that the shaft can linearly move (hereinafter referred to as an actuator with a linear motion guide mechanism) (see Patent Document 1). ). The linear motion guide mechanism-equipped actuator supports the shaft by a spline nut so that the shaft can move linearly, and rotates the spline nut to rotate the shaft around the axis in the θ direction. A linear motor is connected in series or in parallel to a linearly movable shaft. By operating the linear motor, the shaft can be moved in the Z-axis direction.

  A moving body such as a suction pad is attached to one end of the shaft of the actuator with the linear motion guide mechanism. In order to position the rotational position of the moving body in the θ direction, the rotational position of the shaft needs to be detected by a sensor. In a conventional actuator with a linear motion guide mechanism, a magnetic sensor for measuring the magnetic field of the rotor magnet is provided in the housing, and A and B two-phase signals that are out of phase by π / 2 with the rotation of the rotor from the magnetic sensor. Thus, the rotation angle of the rotor was detected. Since the rotation angle of the shaft matches the rotation angle of the rotor, the rotation angle of the shaft can be detected by detecting the rotation angle of the rotor. In addition, the positioning of the moving body in the Z-axis direction is performed by providing a linear encoder on the linear motor side.

International Publication WO2010 / 038570

  In recent years, from the viewpoint of miniaturization of an actuator with a linear motion guide mechanism and from the viewpoint of ease of mounting of the sensor, it is required to provide a sensor at an end portion in the axial direction of the housing of the actuator with a linear motion guide mechanism.

  However, if a sensor is provided at the end of the housing in the axial direction from this requirement, it is necessary to detect the rotational position of the shaft by the sensor at the end of the housing. Since the shaft of the actuator with the linear motion guide mechanism strokes in the axial direction, the length of the scale that cooperates with the sensor must be longer than the stroke of the shaft, and a new problem arises that the scale becomes longer.

  Accordingly, the present invention provides an actuator with a linear motion guide mechanism that can be provided with a sensor that detects the rotational position of the shaft at the axial end portion of the housing, and that can prevent the scale from becoming longer than the stroke of the shaft. The purpose is to do.

  In order to solve the above-described problem, an aspect of the present invention includes a shaft having a spline groove that is guided by a spline nut and linearly moves in an axial direction and extends in the axial direction, a rotor portion of a motor, and the spline. A hollow rotor that rotates together with the nut, a housing in which a stator portion of the motor is provided, and a bearing that is provided at an axial end of the housing and guides the rotation of the hollow rotor around the axis. In the actuator with a linear motion guide mechanism in which the shaft rotates around the axis by the motor rotating the rotor around the axis, a hollow in the axial direction supported by the bearing of the rotor is provided. The end portion of the housing protrudes axially from the bearing from the inside to the outside of the housing, and protrudes from the bearing by the sensor. An actuator with linear motion guide mechanism making it possible to detect the rotational position of the end of the rotor that.

  According to the present invention, the end of the rotor is protruded in the axial direction from the bearing provided at the end of the housing in the axial direction, and the rotational position of the end of the rotor is detected. A sensor for detecting the rotational position of the shaft can be provided in the part. Further, it is possible to prevent the scale from becoming longer than the stroke of the shaft.

Sectional drawing along the axis line of the actuator with a linear motion guide mechanism in 1st embodiment of this invention Plan view of rotor of actuator with linear motion guide mechanism Perspective view of rotor part Cross section of the rotor Perspective view of the first cap Figure VI enlarged view A perspective view of a spin nut (including a partial cross-sectional view) Rotation motor control device configuration diagram Interpolator configuration diagram Memory configuration diagram of lookup table memory Sectional drawing along the axis line of the actuator with a linear motion guide mechanism in 2nd embodiment of this invention The partially expanded sectional view of the actuator with a linear motion guide mechanism in 2nd embodiment of this invention.

  The actuator with a linear motion guide mechanism in the first embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view taken along the axis of a shaft 1 of an actuator with a linear motion guide mechanism in a first embodiment of the present invention. The actuator with a linear motion guide mechanism guides the shaft 1 so as to be capable of linear motion, and rotates the shaft 1 around the axis. A linear motor or the like (not shown) is connected to one end of the shaft 1. The movement amount of the shaft 1 in the axial direction is controlled by a linear motor or the like (not shown).

  The overall configuration of the actuator with the linear motion guide mechanism is as follows. In the center of the housing 2 in the axial direction, a rotary motor 5 including a stator portion 3 and a rotor portion 8 is disposed. The stator portion 3 of the rotary motor 5 includes a coil 6 and is coupled to the housing 2.

  The hollow rotor portion 8 of the rotary motor 5 includes a magnet 7. First and second caps 10 and 9 that enclose the spline nuts 12a and 12b are integrally coupled to both ends of the rotor portion 8 in the left-right direction. The rotor 4 includes a rotor portion 8 and a pair of first and second caps 10 and 9. The rotational movement of the hollow rotor 4 is guided by a pair of bearings 14a and 14b provided at both ends in the left and right direction of the housing 2 outside the pair of spline nuts 12a and 12b. In practice, the axis 1 is often arranged in the vertical direction, but for convenience of explanation, it is assumed that the axis 1 is arranged in the horizontal direction, and the horizontal direction is defined as the left-right direction.

  The shaft 1 is fitted to the pair of left and right spline nuts 12a and 12b so as to be linearly movable in the axial direction. The linear motion of the shaft 1 is guided by a pair of spline nuts 12a and 12b.

  When the rotary motor 5 rotates the hollow rotor 4, the spline nuts 12 a and 12 b integrated with the hollow rotor 4 rotate around the axis together with the hollow rotor 4. When the spline nuts 12a and 12b rotate, the shaft 1 that is non-rotatably engaged with the spline nuts 12a and 12b rotates around the axis. Since the spline nuts 12a and 12b allow the shaft 1 to linearly move in the axial direction, the shaft 1 rotates around the axis while being linearly movable. The hollow rotor 4 and the spline nuts 12a and 12b may be rotated together around the axis, and the spline nuts 12a and 12b may be linearly moved in the axial direction with respect to the hollow rotor 4.

  The detailed configuration of each part of the actuator with the linear motion guide mechanism is as follows. The shaft 1 is formed hollow. A plurality of spline grooves 1 a (see FIG. 7) extending in the axial direction are formed on the outer peripheral surface of the shaft 1. A large number of balls as rolling elements incorporated in the spline nuts 12a and 12b are fitted in the spline groove 1a of the shaft 1 so as to be capable of rolling along the spline groove 1a. The shaft 1 and the spline nuts 12a and 12b are non-rotatably engaged around the axis, and the shaft 1 rotates around the axis along with the rotation of the spline nuts 12a and 12b. Both ends of the shaft 1 in the longitudinal direction protrude from the housing 2. A moving body such as a suction pad and a tool (not shown) is attached to one end of the shaft 1, and a linear motor (not shown) is connected to the other end of the shaft 1.

  The housing 2 is formed in an elongated rectangular parallelepiped shape. A cylindrical space elongated in the axial direction is formed inside the housing 2. A rotary motor 5 is accommodated in the center in the length direction of the space of the housing 2. The rotary motor 5 is a hollow motor. The housing 2 is coupled to the stator portion 3 of the rotary motor 5. The stator section 3 is wound around a large number of magnets of the rotor section 8 facing each other with a magnetic clearance, a large number of cores 21 projecting radially inward from the yoke, and a large number of cores 21. A number of coils 6. The coil 6 is composed of a three-phase coil composed of U, V, and W phases. When a three-phase alternating current is passed through the coil 6, a rotating magnetic field is generated in the stator unit 3, and the rotor 4 is rotated by the interaction between the rotating magnetic field of the stator unit 3 and the magnetic field of the magnet 7.

  As shown in FIG. 1, a pair of bearings 14 a and 14 b that guide the rotation of the hollow rotor 4 are provided at both ends in the length direction of the housing 2. The pair of bearings are disposed outside the pair of spline nuts 12a and 12b in the axial direction. The bearings 14a and 14b include balls as rolling elements interposed between the inner ring, the outer ring, and the inner ring and the outer ring. A flange is formed on the outer ring of the bearings 14a and 14b so that the bearing can be positioned in the axial direction in the housing 2.

  As shown in FIG. 2, the rotor 4 includes a central cylindrical rotor portion 8 provided with a large number of magnets, a pair of second caps 9 coupled to the left and right ends of the rotor portion 8, and a pair of A pair of first caps 10 coupled to the left and right outer sides of the second cap 9. The first cap 10 and the second cap 9 coupled to the rotor portion 8 enclose the spline nuts 12a and 12b. The pair of spline nuts 12a, 12b and the pair of first and second caps 10, 9 arranged on the left and right sides of the rotor portion 8 are symmetrical.

  FIG. 3 is a perspective view of the rotor unit 8. The rotor part 8 is formed in a cylindrical shape. A plurality of (for example, eight) magnets 7 that are elongated in the axial direction of the rotor portion 8 are attached to the rotor portion 8 except for both ends in the axial direction. Reference recesses 8 a for positioning the second cap 9 in the rotational direction with respect to the rotor portion 8 are formed at both ends of the rotor portion 8. Since the first cap 10 and the second cap 9 are positioned in the rotational direction, the rotor portion 8 and the first cap 10 are positioned in the rotational direction. As will be described in detail later, since the Z-phase signal is output using both the magnet 7 of the rotor unit 8 and the sensor dog 10c-2 (see FIG. 5) of the first cap 10, the rotor unit 8 and the first cap 10 must be positioned in the direction of rotation.

  As shown in the cross-sectional view of the rotor portion 8 in FIG. 4, a large number of magnets 7 are attached to the outer peripheral surface of the rotor portion main body 8b so that N poles and S poles are alternately formed in the circumferential direction. The magnet 7 is magnetized in the radial direction, that is, the outer peripheral side is magnetized to one of the N and S poles, and the inner peripheral side is magnetized to the other of the N and S poles.

  As shown in FIG. 1, the end of the magnet 7 in the axial direction protrudes from the stator portion 3 in the axial direction. In the vicinity of the stator portion 3 of the housing 2, a magnetic sensor 26 for measuring the magnetic field of the portion protruding from the stator portion 3 of the magnet 7 is provided. The magnetic sensor 26 includes a magnetoresistive element that measures the magnetic field direction (magnetic vector direction) of the magnet 7 of the rotor unit 8 or the magnitude of the magnetic field. Using the magnet 7 of the rotor unit 8 as a scale, sine wave and cosine wave voltage signals whose phases are shifted by π / 2 are output. Speaking of the magnet 7, the magnet 7 functions as a driving magnet that generates torque for rotating the rotor 4, and also functions as a scale for detecting the rotation angle of the rotor 4.

  The first cap 10 of the rotor 4 protrudes to the opposite side of the peripheral wall 10a from the cylindrical peripheral wall 10a surrounding the spline nut 12b, the bottom wall 10b that closes one end of the peripheral wall 10a, and the bottom wall 10b. The cylindrical protrusion 10c has a smaller diameter than the peripheral wall 10a. A protruding portion 10c serving as an end portion of the rotor 4 is rotatably supported by the bearings 14a and 14b. The protruding portion 10 c includes a sensor dog 10 c-2 that protrudes in the axial direction from the bearings 14 a and 14 b from the inside to the outside of the housing 2. As shown in the perspective view of FIG. 5, only a part of the periphery of the protruding portion 10c protrudes in the axial direction to constitute the sensor dog 10c-2.

  The protruding portion 10c includes a guide portion 10c-1 protruding in a cylindrical shape from the bearings 14a and 14b and a sensor dog 10c-2. The outer diameter of the guide portion 10c-1 is set to be slightly smaller than the portion of the protruding portion 10c supported by the bearings 14a and 14b. The guide portion 10c-1 has a function of guiding the bearings 14a and 14b when the bearings 14a and 14b are inserted into the first cap 10. The sensor dog 10c-2 protrudes in the axial direction from a part of the periphery of the guide portion 10c-1. The cross-sectional shape of the sensor dog 10c-2 is a circular arc, and the central angle of the circular arc is set to 360 ° / the number of poles of the magnetic pole of the magnet, in this embodiment 360 ° / 8 poles (four pole pairs)) = 45 ° or less. The

  As shown in FIG. 6, the rotational position of the sensor dog 10c-2 is detected by a proximity sensor 27 as a sensor. The proximity sensor 27 is attached to the end of the housing 2 in the axial direction via an attachment member such as a bracket 28. No scale is attached to the sensor dog 10c-2. When the sensor dog 10c-2 approaches, the proximity sensor 27 detects the presence / absence of the sensor dog 10c-2 without contacting the sensor dog 10c-2. The proximity sensor 27 is provided at the end of the housing 2 in the axial direction. It is also possible to use a limit switch instead of the proximity sensor 27.

  As shown in FIG. 1, spline nuts 12 a and 12 b and seals 31 a and 31 b are accommodated in the peripheral wall portion 10 a of the first cap 10. The resin seals 31a and 31b prevent foreign matter from entering the spline nuts 12a and 12b. After the spline nuts 12a and 12b and the seals 31a and 31b are stored in the peripheral wall portion 10a, the spline nuts 12a and 12b are fixed to the peripheral wall portion 10a with an adhesive. A plurality of through holes 32 are formed in the circumferential wall portion 10a in the radial direction at equal intervals in the circumferential direction (see FIG. 5). An adhesive is injected into the inside through the through hole 32 from the outside of the peripheral wall portion 10a. Grooves 33 extending in the circumferential direction are formed on the outer peripheral surfaces of the spline nuts 12a and 12b (see FIG. 7). The groove 33 is connected to the through hole 32 of the peripheral wall portion 10a, and the adhesive spreads around the spline nuts 12a and 12b.

  The bottom wall portion 10b that connects the peripheral wall portion 10a and the protruding portion 10c is formed in an annular shape. A shoulder portion 10b-1 that abuts against the inner ring of the bearings 14a and 14b is formed between the bottom wall portion 10b and the protruding portion. The rotor 4 is positioned between the pair of bearings 14a and 14b by abutting the shoulder 10b-1 against the inner rings of the pair of bearings 14a and 14b.

  The second cap 9 is fitted to the first cap 10 in which the spline nut 12b is accommodated like a lid. The second cap 9 includes a fitting convex portion 9a that fits inside the peripheral wall portion 10a of the first cap 10, and an abutting portion 9b that abuts against an end surface in the axial direction of the peripheral wall portion 10a of the first cap 10. And the fitting recessed part 9c by which the rotor part 8 is fitted is provided. As described above, the rotor portion 8 and the second cap 9 are positioned in the rotational direction.

  FIG. 7 is a perspective view of the spline nuts 12a, 12b and the shaft 1 (partial cross-sectional view of the spline nuts 12a, 12b). A spline groove 1 a extending in the longitudinal direction is formed on the outer peripheral surface of the shaft 1. A circulation path including a rolling element rolling groove 34 facing the spline groove of the shaft 1 is formed in the spline nuts 12a and 12b.

  The spline nuts 12 a and 12 b include a central cylindrical nut body 35 and a pair of lid members 36 provided at both ends of the nut body 35 in the axial direction. The nut body 35 is formed with the rolling element rolling groove 34 and a no-load return path 37 parallel to the rolling element rolling groove 34. The lid member 36 is formed with a U-shaped direction changing path that connects the rolling element rolling groove 34 and the no-load return path 37. A circuit-shaped circulation path is formed by the rolling element rolling groove 34, the no-load return path 37, and the pair of direction changing paths. A large number of balls 38 are arranged as rolling elements in the circulation path. When the shaft 1 linearly moves in the axial direction with respect to the spline nuts 12a and 12b, a large number of balls 38 roll between the shaft 1 and the spline nuts 12a and 12b and circulate in the circulation path.

  The assembly method of the actuator with the linear motion guide mechanism is as follows. First, as shown in FIG. 2, the second cap 9 is fitted to both end portions in the axial direction of the rotor portion 8 of the hollow rotor 4. Next, in a state where the spline nuts 12 a and 12 b are accommodated in the first cap 10, the peripheral wall portion 10 a of the first cap 10 is fitted to the fitting convex portion 9 a of the second cap 9. After the spline nuts 12a and 12b are coupled and integrated with the rotor 4, the shaft 1 is passed through the spline nuts 12a and 12b.

  Next, as shown in FIG. 1, the stator portion 3 of the rotary motor 5 is coupled to the housing 2. The rotor 4 and the shaft 1 assembled in the hollow space of the housing 2 are inserted, and the bearings 14a and 14b are fitted into both ends of the housing 2 in the axial direction. The bearings 14 a and 14 b are fitted on the outside of the first cap 10. Finally, lids 40a and 40b for holding the bearings 14a and 14b are attached to both ends of the housing 2 so that the bearings 14a and 14b do not fall off.

  FIG. 8 shows a block diagram of a control device for an actuator with a linear motion guide mechanism. The control device 51 includes a power converter 53 such as a PWM inverter (PWM: Pulse Width Modulation) that supplies power in a form suitable for controlling the rotary motor 5, and a magnetic sensor 26 that measures the magnetic field of the rotor 4. An interpolator 54 that interpolates the output signal and a controller 52 that controls the power converter 53 based on information from the command unit 55 are provided. The ON signal of the proximity sensor 27 is input to the controller 52. The controller 52 controls the rotary motor 5 so that the rotational position of the rotor 4 matches the command value from the command device 55.

  The magnetic sensor 26 detects a change in the magnetic field direction (magnetic vector direction) of the rotor 4 and outputs sine wave and cosine wave voltage signals having a π / 2 phase shift. The voltage signal output from the magnetic sensor 26 is output to the interpolator 54. The interpolator 54 calculates the angle information of the rotor 4 based on the sine wave and cosine wave voltage signals.

  FIG. 9 shows a configuration diagram of the interpolator 54. The sine wave signal and cosine wave signal output from the magnetic sensor 26 are taken into the interpolator 54. The interpolator 54 performs digital interpolation processing on the sine wave signal and cosine wave signal having a 90 ° phase difference, and outputs phase angle data with high resolution. In using the magnet 7 of the rotor 4 as a magnetic scale, it is necessary to subdivide the sine wave signal and the cosine wave signal output from the magnetic sensor 26 to increase the resolution. This is because the magnetic pole pitch of the magnet 7 of the rotor 4 is coarser than the magnetic pole pitch of the magnetic scale. A sine wave signal and a cosine wave signal having different 90 ° phases are input to the A / D converters 61 and 62, respectively. The A / D converters 61 and 62 sample the sine wave signal and the cosine wave signal, respectively, into digital data DA and DB at a predetermined cycle. The signal processing unit 63 outputs pulsed A-phase signals and B-phase signals from the digital data DA and DB.

The signal processing method of the signal processing unit 63 is as follows. As shown in FIG. 10, lookup table data created based on Equation ¹ using an arctangent function (TAN ⁻¹ ) is recorded in the lookup table memory 64 in advance.
(Equation 1)
u = TAN ^-1 (DB / DA)

FIG. 10 shows a memory configuration of a look-up table memory in which phase angle data of 1000 divisions per cycle is provided in an 8-bit × 8-bit address space. The signal processing unit 63 searches the look-up table data using the digital data DA and DB as x and y addresses, respectively, and obtains phase angle data u corresponding to the x and y addresses. As a result, it becomes possible to divide and interpolate within one wavelength (section from 0 to 2π). Instead of using a look-up table memory, an operation of u = TAN ⁻¹ (DB / DA) is performed to calculate the phase angle data u, thereby dividing one wavelength (section from 0 to 2π). -Interpolation may be used.

  The signal processing unit 63 shown in FIG. 9 outputs a pulsed A-phase signal and B-phase signal from the phase angle data u. In addition, the signal processing unit 63 outputs a Z-phase signal using the zero cross of the sine wave signal and the cosine wave signal output from the magnetic sensor 26. A number of Z-phase signals equal to the number of poles of the rotor portion 8 of the rotary motor are output. For example, if the number of poles of the magnet 7 is 8, 8 Z-phase signals are output. However, in order to position the rotational position of the shaft 1, it is necessary to obtain the Z-phase signal only once in one rotation of the rotor 4. If an attempt is made to obtain a Z-phase signal (also referred to as a zero signal) only once in one rotation of the rotor 4 from the magnetic sensor 26, a separate scale for outputting only one Z-phase signal per round is required. Therefore, one of the eight Z-phase signals already obtained is specified. In order to identify one of the eight Z-phase signals and obtain the Z-phase signal only once in one rotation of the rotor 4, the output signal of the proximity sensor 27 provided at the end of the housing 2 is additionally provided. Use.

  The controller 52 shown in FIG. 8 specifies a Z-phase signal when the proximity sensor 27 simultaneously outputs an ON signal among the eight Z-phase signals input from the interpolator 54. Then, based on the A and B phase signals input from the interpolator 54 and the specified Z phase signal, the rotational position of the rotary motor 5 is known, and power is supplied so that the rotational position of the rotary motor 5 matches the command value. The converter 53 is controlled.

  According to this embodiment, the following effects can be obtained.

  Since the end of the rotor 4 protrudes in the axial direction from the bearings 14a and 14b provided at the end in the axial direction of the housing 2, the rotational position of the end of the rotor 4 is detected. A proximity sensor 27 that detects the rotational position of the shaft 1 can be provided at the end. Further, it is possible to prevent the scale from becoming longer than the stroke of the shaft 1.

  Since the sensor dog 10c-2 (end portion of the rotor 4) protruding from the shaft 1 is formed in the first cap 10 that wraps the spline nuts 12a and 12b, the actuator with the linear motion guide mechanism can be made compact.

  The sensor dog 10c-2 of the first cap 10 is formed so as to protrude in the axial direction from a part of the periphery, and the sensor dog 10c-2 is detected by the proximity sensor 27, so once per rotation of the rotor 4 Only an output signal can be output easily.

  By using the magnetic sensor 26 and the proximity sensor 27 in combination, the Z-phase signal can be specified only once for one rotation of the rotor 4.

  FIG. 11 shows an actuator with a linear motion guide mechanism in a second embodiment of the present invention. The structure of the shaft 1, the housing 2, the rotary motor 5, the pair of spline nuts 12a and 12b, the pair of bearings 14a and 14b, the rotor portion 8 constituting the rotor 4, and the second cap 9 is the straight line of the first embodiment. Since it is the same as the actuator with the motion guide mechanism, the same reference numerals are given and the description thereof is omitted.

  In this embodiment, unlike the first embodiment, the entire circumference around the cylindrical protrusion 70c of the first cap 70 as the end of the rotor 4 is protruded in the axial direction from the bearings 14a and 14b. . As shown in the enlarged sectional view of FIG. 12, a ring-shaped magnetic scale 72 is attached to the protruding portion 70 c of the first cap 70 over the entire circumference. The scale of the magnetic scale 72 includes a scale for outputting the A and B phase signals and a scale for outputting the Z phase signal. The magnetic field of the magnetic scale 72 is measured by the rotary encoder 73. The rotary encoder 73 is attached to the end of the housing 2 in the axial direction. A lid portion 74 in which the rotary encoder 73 is accommodated is attached to an end portion in the axial direction of the housing 2 (see FIG. 11). By processing the output signal of the rotary encoder 73, it is possible to obtain the A and B phase signals whose phases are shifted by π / 2 with the rotation of the rotor 4 and the Z phase signal only once in one rotation of the rotor 4. it can. The rotary encoder 73 may be an optical type.

  According to the present embodiment, A and B phase signals whose phases are shifted by π / 2 with the rotation of the rotor 4, and a Z phase signal can be obtained only once with one rotation of the rotor 4. Unlike the actuator with the linear motion guide mechanism of the first embodiment, since the magnetic scale is not provided in the housing 2, the actuator with the linear motion guide mechanism can be further downsized.

  The present invention is not limited to being embodied in the above-described embodiment, and can be variously modified without changing the gist of the present invention.

  For example, the actuator with a linear motion guide mechanism of the above embodiment is not limited to the chip mounter, and can be widely used as an actuator with a linear motion guide mechanism of a robot.

  The actuator with linear motion guide mechanism of the above embodiment may be used with only one axis, or may be used with multiple axes by combining a plurality of actuators with linear motion guide mechanisms so that the axes are parallel.

  The number and layout of spline nuts and bearings are not limited to the above embodiment, and one spline nut and one bearing may be provided.

  The shapes of the housing, the rotor, and the first and second caps are merely examples, and various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Shaft, 1a ... Spline groove, 2 ... Housing, 3 ... Stator part, 4 ... Rotor, 5 ... Rotating motor, 10c-2 ... Sensor dog (end part of rotor), 12a, 12b ... Spline nut, 14a, 14b ... Bearing, 26 ... Magnetic sensor, 27 ... Proximity sensor (sensor), 73 ... Rotary encoder (sensor), 70c ... Projection (end of rotor)

Claims (6)

A shaft having a spline groove that is guided by the spline nut and linearly moves in the axial direction and extends in the axial direction;
A rotor portion of the motor is provided, and a hollow rotor that rotates together with the spline nut;
A housing in which a stator portion of the motor is provided;
A bearing provided at an axial end of the housing and guiding the hollow rotor rotating about the axis;
In the actuator with a linear motion guide mechanism in which the shaft rotates around the axis by the motor rotating the rotor around the axis,
A hollow end portion in the axial direction supported by the bearing of the rotor is protruded in the axial direction from the bearing toward the outside from the inside of the housing,
An actuator with a linear motion guide mechanism that makes it possible to detect the rotational position of the end of the rotor protruding from the bearing by a sensor. The rotor includes a cap that wraps at least part of the outer peripheral surface of the spline nut;
The actuator with a linear motion guide mechanism according to claim 1, wherein an end of the rotor is formed on the cap.   The actuator with a linear motion guide mechanism according to claim 1, wherein the sensor is arranged in a radial direction of an end portion of the rotor. The end of the rotor has a sensor dog,
4. The actuator with a linear motion guide mechanism according to claim 1, wherein a proximity sensor or a limit switch as the sensor detects a rotational position of the sensor dog. 5. The housing is provided with a magnetic sensor that measures the direction or magnitude of the magnetic field of the magnet of the rotor portion,
By using the output signal of the magnetic sensor, it is possible to obtain A, B2 phase signals that are out of phase by π / 2 with the rotation of the rotor,
The Z-phase signal can be obtained only once in one rotation of the rotor by using the output signal of the magnetic sensor and the output signal of a proximity sensor or limit switch as the sensor. The actuator with a linear motion guide mechanism according to any one of 4. The sensor is a rotary encoder;
The entire circumference around the end of the rotor protrudes in the axial direction,
Around the end of the rotor is attached a scale that cooperates with the sensor,
By using the rotary encoder, it is possible to obtain A and B phase signals whose phases are shifted by π / 2 with the rotation of the rotor, and a Z phase signal only once in one rotation of the rotor. The actuator with a linear motion guide mechanism according to claim 1 or 2.

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