JPWO2008117654A1 - Small rotary motor and X-θ actuator using the same - Google Patents

Abstract

By reviewing the positional relationship between the magnet (5) and the coil member (6) in the motor housing (4), it is possible to flatten the space where these magnets and the coil member are arranged, and the small diameter of the motor housing. And a motor rotor (3) that is rotatably supported with respect to the motor housing (4), and is mounted on one of the motor rotor and the motor housing and has a periphery thereof. A magnet (5) in which N poles and S poles are alternately arranged along a direction, and fixed to the motor housing or the motor rotor to face the magnet, generate a rotating magnetic field, and rotate torque to the motor rotor. The magnet and the coil member are opposed to each other along the direction of the rotation axis.

Description

  The present invention relates to a rotary motor, such as an AC motor or a stepping motor, that uses a magnetic attractive force acting between a magnet and a coil member to obtain the rotational torque of a motor rotor, and more specifically, in combination with a linear motor actuator. The present invention relates to a small rotary motor that is optimal for miniaturization of such an X-θ actuator when an X-θ actuator is manufactured.

  2. Description of the Related Art Conventionally, so-called linear motor actuators using linear motors are known as actuators that impart translational motion to articles, members, and the like in FA devices such as an XY table and an article transport device. Various types of linear motor actuators are known. One of them is a so-called rod-type linear motor actuator (Japanese Patent Laid-Open No. 11-150973). This rod type linear motor actuator is formed in a rod shape, and N poles and S poles are repeatedly arranged at a predetermined pitch along the axial direction, and both ends of the magnet rod as a stator supported on the base plate, The forcer is loosely fitted around the magnet rod through a slight gap, and when the coil member provided in the forcer is energized, the forcer moves around the magnet rod in the axial direction. Configured to move along.

On the other hand, a so-called X-θ actuator in which the linear motor actuator and a rotary motor are combined is known as an actuator that gives a rotational motion in addition to a translational motion to articles, members, and the like that are objects to be conveyed (Japanese Patent Laid-Open No. 2004-364348). ). This X-θ actuator has a rotary motor attached outside the forcer of the linear motor actuator, and rotatably supports the forcer with respect to the motor housing, and a stator coil is provided inside the motor housing. On the other hand, a rotor magnet is provided on the outer side of the forcer, and an arbitrary amount of rotation can be given to the forcer by energizing the stator coil. Therefore, by combining the rotational motion of the forcer and the translational motion of the magnet rod by the linear motor actuator, it is possible to give an X-θ motion that combines the translational motion and the rotational motion to the magnet rod. .
JP-A-11-150973 JP 2004-364348 A

  However, in this conventional X-θ actuator, a forcer is provided around the magnet rod, a rotor magnet of the rotary motor is provided around the forcer, and a stator coil is provided around the rotor magnet. Since the magnet and coil member constituting the linear motor actuator and the magnet and coil member constituting the rotary motor are stacked in the radial direction of the magnet rod, the outer diameter of the X-θ actuator is increased. There was a problem.

  In particular, when trying to increase the output of the translational motion and the rotational motion applied to the magnet rod, the number of windings of the coil members in the linear motor portion and the rotary motor portion is increased by that amount, and these coil members increase in size. There was a problem that the outer diameter of the θ actuator had to be increased.

  The present invention has been made in view of such problems, and the object of the present invention is to review the positional relationship between the magnet and the coil member in the motor housing, thereby flattening the arrangement space of the magnet and the coil member. An object of the present invention is to provide a small-sized rotary motor capable of reducing the diameter of the motor housing.

  Another object of the present invention is to increase the output of translational motion and rotational motion without increasing the outer diameter by combining such a small rotary motor and linear motor actuator of the present invention. The object is to provide an X-θ actuator.

  In order to achieve the above object, a small-sized rotary motor of the present invention is mounted on a motor rotor that is rotatably supported with respect to a motor housing, and either the motor rotor or the motor housing and along the circumferential direction thereof. A magnet having alternating N poles and S poles, and a coil member fixed to the motor housing or the motor rotor, facing the magnet, generating a rotating magnetic field, and applying rotational torque to the motor rotor The magnet and the coil member are opposed to each other along the rotation axis direction.

  An X-θ actuator using this small rotary motor has an output shaft in which a large number of magnetic poles are arranged at a predetermined pitch along the axial direction, and a through hole into which the output shaft is loosely fitted. And a forcer that moves the output shaft in the axial direction according to an applied electric signal, and the motor rotor of the small-sized rotary motor of the present invention described above is provided outside the forcer. The motor is configured to give an arbitrary rotation to the forcer.

  According to the small rotary motor of the present invention configured as described above, the coil member that generates the rotating magnetic field and the magnet facing the coil member are opposed to each other along the direction of the rotation axis of the motor rotor. Compared to a conventional rotary motor in which magnets are stacked in the radial direction, the arrangement space of the coil member and the magnet can be flattened in the radial direction, and the radial size of the motor housing can be reduced. .

  Further, when the X-θ actuator is configured by combining the linear motor actuator and the rotary motor, by providing the rotary motor of the present invention outside the forcer of the linear motor actuator, the outer diameter of the X-θ actuator can be reduced. Miniaturization can be achieved, and it is possible to simultaneously achieve high output and miniaturization of translational motion and rotational motion.

It is sectional drawing which shows the small rotation motor embodiment of this invention. It is a figure which shows the arrangement | sequence state of the rotor magnet in a motor rotor. It is a figure which shows a mode that the stator coil and rotor magnet which were arranged in the circumferential direction were expand | deployed on the plane. It is sectional drawing which shows the X-theta actuator using the rotary motor of this invention. It is the schematic which shows the structure of the magnet rod and forcer of a linear motor actuator. It is explanatory drawing which shows the effect | action of the magnetic flux between a magnet rod and a forcer. It is sectional drawing which shows the torque transmission mechanism between a motor rotor and a magnet rod.

  Hereinafter, a rotary motor of the present invention and an X-θ actuator using the same will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing an embodiment of a small rotary motor of the present invention. The rotary motor 1 includes an output shaft 2, a motor rotor 3 fitted to the output shaft 2, a motor housing 4 that rotatably supports the motor rotor 3 via a bearing 30, and a rotation fixed to the motor rotor 3. The stator magnet 5 is composed of a stator coil 6 fixed in the motor housing 4 and facing the rotor magnet 5. In the rotary motor 1, by energizing the stator coil 6, a magnetic attractive force acts between the stator coil 6 and the rotor magnet 5, and a rotational torque acts on the motor rotor 3. It has become.

  The motor rotor 3 has journal portions 31 fixed to the outer peripheral surface of the output shaft 2, and has a pair of flange portions 32 at both ends of the journal portion 31 in the axial direction. The flange portions 32 and the motor housing 4 The enclosed space is a housing space for the stator coil 6 and the rotor magnet 5. In addition, the bearing 30 is fixed to the outer peripheral surface of each flange portion 32, and the motor rotor 3 and the motor housing 4 are rotatably assembled via the bearing 30.

  The rotor magnet 5 is fixed to the inner surface of each flange portion 32 provided in the motor rotor 3. FIG. 2 is a diagram showing the arrangement of the rotor magnet 5 in each flange portion 32. The rotor magnet 5 is arranged on the inner surface of the flange portion 32 so as to surround the journal portion 31, and N poles and S poles are alternately arranged along the circumferential direction. However, in the pair of rotor magnets 5 fixed to each flange portion 32, the magnetic poles facing each other across the stator coil 6 have different polarities, that is, N and S poles.

  On the other hand, the stator coil 6 constitutes a synchronous motor coupled with the rotor magnet 5, and generates a rotating magnetic field around the motor rotor 3 by applying a three-phase alternating current. This stator coil is formed by applying a winding 61 to a plurality of core members 60 serving as an iron core, and has a coil group including three coils of U, V, and W phases as one set. Yes. Each core member 60 is formed in a rod shape, and is positioned between the pair of flange portions 32 of the motor rotor 3 so that the longitudinal direction thereof coincides with the axial direction of the output shaft. Facing each other through a gap. The said winding 61 is made so that the magnetic flux which penetrates each core member 60 may correspond with the longitudinal direction of the said core member 60, ie, the opposing direction of each core member 60 and the rotor magnet 5. FIG. The stator coil 6 configured in this manner is fixed to the inner peripheral surface of the motor housing 4.

  FIG. 3 is a view showing a state in which the rotary motor 1 shown in FIG. 1 is cut at one place in the circumferential direction and the stator coil 6 and the rotor magnet 5 are developed. As shown in this figure, the rotor magnets 5 are arranged inside the flange portions 32 of the motor rotor 3, and the pair of rotor magnets 5 facing each other with the stator coil 6 interposed therebetween has one polarity. Is the N pole and the other polarity is the S pole. A stator coil 6 is disposed between the rotor magnets 5, and both ends of a rod-shaped core member 60 are opposed to the rotor magnet 5.

  In FIG. 3, the direction of arrow A matches the circumferential direction of the motor housing 4, but a plurality of core members 60 arranged along the circumferential direction have a u-phase, a v-phase, and a three-phase alternating current. A winding wire 31 corresponding to the w phase is wound in order. The arrangement pitch of the core members 60 of each phase is set shorter than the arrangement pitch of the rotor magnets 5. Therefore, when a three-phase alternating current is applied to the stator coil 6, a rotating magnetic field is generated around the motor rotor 3 in the stator coil 6, and the rotating magnetic field acts on the rotor magnet 5. Rotational torque is generated in the motor rotor 3. Thereby, the motor rotor 3 is rotated according to the rotational speed of the rotating magnetic field, and rotational power can be applied to the output shaft 2 fitted thereto.

  In the rotary motor 1 of the present invention configured as described above, the rotor magnet 5 and the stator coil 6 face each other along the axial direction of the output shaft 2 that rotates. The accommodation space for the rotor magnet 5 and the stator coil 6 formed by the motor housing 4 can be formed thin in the radial direction. In the conventional rotary motor, since the rotor magnet and the stator coil are opposed to each other along the radial direction, the space for accommodating the rotor magnet and the stator coil must be set large in the radial direction, and only that much. Although the outer diameter of the motor housing has been increased, according to the present invention described above, it is possible to reduce the outer diameter of the motor housing 4 and to reduce the size of the rotary motor 1.

  FIG. 4 is a diagram showing an embodiment of an X-θ actuator configured by combining the rotary motor of the present invention and a rod type linear motor actuator.

  The X-θ actuator includes a rotary motor 10, a magnet rod 7 serving as an output shaft that passes through the motor rotor 3 of the rotary motor 10, and a loose gap around the magnet rod 7 with a slight gap and the motor rotor. 3 and a forcer 8 integrated therewith. The magnet rod 7 and the forcer 8 constitute a linear motor. The configuration of the rotary motor 10 is exactly the same as the configuration of the rotary motor 1 shown in FIG. 1, and the same reference numerals as those in FIG. 1 are given in FIG. 4, and detailed description thereof is omitted here.

  FIG. 5 is a schematic view showing a linear motor composed of the magnet rod 7 and the forcer 8. A plurality of field magnets 70 are arranged on the magnet rod 7 along the axial direction, and the outer peripheral surface is processed smoothly. Each field magnet 70 has an N pole and an S pole, and the adjacent field magnets 70 are arranged with their directions alternately reversed so that the N poles or the S poles face each other. Thereby, the magnet rod 7 is formed with a magnetizing portion for driving in which N-pole magnetic poles and S-pole magnetic poles are alternately arranged along the longitudinal direction thereof.

  On the other hand, the forcer 8 is configured by accommodating a cylindrical coil member 80 on the inner peripheral surface of the journal portion 31 of the motor rotor 3. Also in this linear motor, the coil member 80 has a coil group in which three sets of U, V and W phases are set. As shown in FIG. 6, the coil member 80 of any phase has a ring shape along the circumferential direction of the motor rotor 3, and faces the outer peripheral surface of the magnet rod 7 with a slight gap. The arrangement pitch of the coil members 80 of each phase is set shorter than the arrangement pitch of the field magnets 70. A magnetic flux 71 is formed on the macnet rod 7 from the magnetic pole of the S pole toward the magnetic pole of the N pole. The motor rotor 3 includes a magnetic pole sensor (not shown) for detecting the magnetic flux density. Therefore, the positional relationship of each magnetic pole (N pole and S pole) of the magnet rod 7 with respect to the coil member 80 is grasped from the detection signal output from the magnetic pole sensor. The controller that controls the energization of the coil member 80 receives the detection signal of the magnetic pole sensor, calculates the optimum current according to the positional relationship between the coil member 80 and each magnetic pole of the magnet rod 7, The coil member 80 is energized. As a result, an attractive force and a repulsive force are generated between the coil member 80 and each magnetic pole of the field magnet 70 due to the interaction between the current flowing through each coil member 80 and the magnetic flux 71 formed by the field magnet 70. The forcer 8 is propelled in the axial direction of the magnet rod 7 together with the motor rotor 3.

  FIG. 7 shows a torque transmission mechanism 9 between the motor rotor 3 and the magnet rod 7. The forcer 8 only propels the magnet rod 7 in its axial direction, and does not transmit any rotational torque around its axis to the magnet rod 7. Therefore, in order to transmit the rotation of the motor rotor 3 to the magnet rod 7, it is necessary to couple the motor rotor 3 and the magnet rod 7 using such a torque transmission mechanism 9.

  The torque transmission mechanism 9 is fixed to the motor rotor 3 and has a base plate 90 through which the magnet rod 7 passes, and a pair of the base plate 90 erected on the base plate 90 in parallel with the magnet rod 7 and sandwiching the magnet rod 7. A guide shaft 91, a pair of guide bushes 92 that are movable in the direction of arrow A along each guide shaft 91, and a connecting plate 93 that holds these guide bushes 92 and is fixed to the end of the magnet rod 7; It is composed of

  The connecting plate 93 fixed to the magnet rod 7 is supported by two guide shafts 91 via guide bushes 92 and is movable along the axial direction of the guide shafts 91. For this reason, when the magnet rod 7 advances and retracts in the axial direction by energization of the forcer 8, the connecting plate 93 moves along the guide shaft 91 together with the magnet rod 7. On the other hand, when the motor rotor 3 rotates, a pair of guide shafts 91 erected on the base plate 90 revolve around the magnet rod 7, and the rotational torque is transmitted to the connecting plate 93 guided by the guide shaft 91. As a result, the rotational torque applied to the motor rotor 3 is transmitted to the magnet rod 7 via the connecting plate 93.

  Therefore, according to the torque transmission mechanism 9, the rotational torque of the motor rotor 3 can be transmitted to the magnet rod 7 while allowing the linear motor to advance and retract in the axial direction of the magnet rod 7.

  As another form for transmitting the rotational torque of the motor rotor 3 to the magnet rod 7, for example, a form using a ball spline is conceivable. Specifically, a spline shaft is provided at one shaft end of the magnet rod 7, and a spline nut fitted to the spline shaft is fixed to the end portion of the motor rotor 3. As a result, the magnet rod 7 is guided to the motor rotor 3 so as to be movable back and forth in the axial direction, and the magnet rod 7 is prevented from rotating around the motor rotor 3, so that the rotation of the motor rotor 3 can be transmitted to the magnet rod 7. Become.

  In the X-θ actuator configured as described above, the magnet rod 7 can be advanced and retracted by an arbitrary amount with respect to the motor rotor 3 by energizing the coil member 80 of the forcer 8 and rotating. By energizing the stator coil 6 of the motor 10, the motor rotor 3 can be rotated by an arbitrary amount, and the magnet rod 7 can be rotated around the axial direction. It is possible to give both translational motion and rotational motion to the workpiece gripped by the holding means such as a chuck.

  At this time, in the rotary motor 10, since the rotor magnet 5 and the stator coil 6 face each other along the axial direction of the magnet rod 7, the journal portion 31 and the motor housing 4 of the motor rotor 3 are formed. The housing space for the rotor magnet 5 and the stator coil 6 to be formed can be made thin in the radial direction, and the motor housing 4 is large even when the linear motor forcer 8 is housed in the motor rotor 3. It is possible to suppress the diameter. That is, the X-θ actuator of the present invention in which the rotary motor is stacked on the outer diameter side of the linear motor actuator can achieve the miniaturization of the motor housing 4 and provides an X-θ actuator useful in various FA devices. It is possible to do.

In the rotary motor 1 described with reference to FIG. 1, the rotor magnet 5 is mounted on the motor rotor 3 and the stator coil is mounted on the motor housing 4. However, by changing the shapes of the motor rotor and the motor housing, A magnet as a stator may be mounted on the motor housing, and a coil member as a rotor may be mounted on the motor rotor.

Claims (3)

A motor rotor (3) rotatably supported with respect to the motor housing (4), and mounted on one of the motor rotor (3) and the motor housing (4) and along the circumferential direction of the N pole and S Magnets (5) in which poles are alternately arranged, and fixed to the motor housing (4) or the motor rotor (3) to face the magnet (5) and generate a rotating magnetic field, to the motor rotor (3) A small rotary motor comprising a coil member (6) for applying rotational torque to the magnet (5) and the coil member (6) facing each other in the direction of the rotation axis. The small rotary motor according to claim 1, wherein the magnets (5) are arranged in two rows so as to sandwich the coil member (6) from both sides in the axial direction. A magnet rod (7) in which a large number of magnetic poles are arranged at a predetermined pitch along the axial direction, and a through-hole into which the magnet rod (7) is loosely fitted, and together with the magnet rod (7) constitute a linear motor And a forcer (8) for moving the magnet rod (7) in the axial direction in accordance with an applied electric signal,
The motor rotor (3) of the small rotary motor (1) according to claim 1 is provided outside the forcer (8), and the rotary motor (1) gives an arbitrary rotation to the forcer (8). -Θ actuator.

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