JP6367025B2 - Positioning device - Google Patents

Positioning device Download PDF

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JP6367025B2
JP6367025B2 JP2014140530A JP2014140530A JP6367025B2 JP 6367025 B2 JP6367025 B2 JP 6367025B2 JP 2014140530 A JP2014140530 A JP 2014140530A JP 2014140530 A JP2014140530 A JP 2014140530A JP 6367025 B2 JP6367025 B2 JP 6367025B2
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ring
nut
stator
preload
axial
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JP2016017570A (en
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高田 声一
声一 高田
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Ntn株式会社
Ntn株式会社
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16CSHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00Bearings with rolling contact, for exclusively rotary movement
    • F16C19/22Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings
    • F16C19/34Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for both radial and axial load
    • F16C19/36Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for both radial and axial load with a single row of rollers
    • F16C19/361Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for both radial and axial load with a single row of rollers with cylindrical rollers
    • F16C19/362Bearings with rolling contact, for exclusively rotary movement with bearing rollers essentially of the same size in one or more circular rows, e.g. needle bearings for both radial and axial load with a single row of rollers with cylindrical rollers the rollers being crossed within the single row

Description

  The present invention converts the relative rotational motion of the nut with respect to the screw shaft into the relative linear motion of the nut with respect to the screw shaft, and when the nut stops at a target position with respect to the screw shaft, The present invention relates to a positioning device that can be held at the position.
  This type of positioning device is used for the purpose of linearly moving one of two bodies of a robot, a machine tool or the like relative to the other. One of the screw shaft or nut is fixed to one of the two bodies, and the other of the screw shaft or nut is fixed to the other. The screw shaft and the nut are a slide screw or a ball screw (hereinafter collectively referred to as “feed screw”). The positioning device includes an actuator for rotating the nut. As the actuator, an ultrasonic motor has been conventionally used (Patent Documents 1 and 2).
  Among them, the positioning device of Patent Document 2 using the composite vibrator type stator can increase the output and can also rotate at a low speed. When the stator is stopped, the pre-pressure that presses the stator to the output side becomes the braking force, so that the nut can be kept at the target position. As described above, when the composite vibrator type stator is employed, it is not necessary to incorporate a reduction gear or an electromagnetic brake, and a positioning device having a simple structure can be obtained. In addition, since the positioning device of Patent Document 2 has a stator arranged outside the bearing that supports the rotor portion in the radial direction, the bearing is not easily affected by wear powder from the ultrasonic motor, and prevents damage to the bearing. Is also advantageous.
Japanese Patent No. 4137479 JP-A-6-113570
  However, the positioning device of Patent Document 2 accommodates a stator, a nut, and the like inside a case, directly drives the nut with the stator, and uses a bearing, an annular plate, and a fixing bolt for supporting the joint of the stator. The structure is connected to the end face of the case. For this reason, in the positioning device of Patent Document 2, when changing the feed speed of the feed screw, the size of the screw shaft, and the like, the contact position between the stator and the nut and the connection destination of the stator are associated with the change in the nut size. The case end face position may need to be changed, and in this case, there will be many changed parts other than the feed screw.
  Therefore, the problem to be solved by the present invention is to provide a positioning device that can easily cope with a change of a feed screw driven by a composite vibrator type stator.
  In order to achieve the above object, the present invention converts the relative rotational movement of the nut with respect to the screw shaft into the relative linear motion of the nut with respect to the screw shaft, and the nut is intended for the screw shaft. In a positioning device that can be held at that position by braking force, a rolling bearing having an inner ring connected to the nut, an outer ring surrounding the inner ring, and a rolling element that rolls between the inner ring and the outer ring, and A configuration including a composite vibrator type stator that is connected to an outer ring and applies a driving force to the nut via the inner ring is adopted.
  When the stator is connected to the outer ring of the rolling bearing and the nut is connected to the inner ring, the stator and the nut are connected via the rolling bearing. For this reason, the driving force of the stator can be applied to the nut via the inner ring. That is, the input path between the inner ring and the stator is independent of the output path between the inner ring and the nut. For this reason, it is possible to change a lead screw, without changing an input path. Further, if there is no need to change the input path, there is no change in the positional relationship between the inner ring and the stator, and there is no need to change the connection structure between the outer ring and the stator that constitute the rolling bearing together with the inner ring. Therefore, according to the said structure, it is possible to respond | correspond to the change of a feed screw only by the change of the output side components connected with an inner ring | wheel. The output side component refers to a component that is rotated integrally with the inner ring by a driving force generated by the stator.
In the present invention, an encoder that is connected to the inner ring and converts the rotational motion of the inner ring into a physical signal, a sensor circuit that is connected to the outer ring and converts the physical signal into an output signal,
Preferably, the stator is disposed on one side in the axial direction with the rolling bearing as a boundary, and the encoder and the sensor circuit are disposed on the other side in the axial direction with the rolling bearing as a boundary. . In this way, the stator and the rotation sensor (encoder and sensor circuit) are unitized in the rolling bearing, the rotational motion of the inner ring driven by the stator is converted into an output signal, and the stator is controlled based on the output signal. It becomes possible. As a result, the feed screw can be accurately fed.
  Moreover, it is preferable that the rolling bearing is a cross roller bearing. When the stator is connected to the outer ring and the inner ring is directly driven by the stator, the rolling bearing simultaneously receives a complicated load derived from the stator. Since the cross roller bearing is a bearing in which cylindrical rollers are assembled in an orthogonal arrangement between the inner and outer rings, it has a feature that it can be made compact while receiving loads in various directions at the same time. Therefore, in this invention, when a cross roller bearing is adopted as the rolling bearing, the size of the rolling bearing can be suppressed while accommodating a complicated load, and the positioning device can be made compact.
  The nut and the screw shaft are provided as a slide screw or a ball screw. By changing the output side part and the screw shaft, it is possible to switch the feed screw type without changing the rolling bearing and the stator.
  Moreover, in this invention, it is further provided with the attachment bolt screwed into the said inner ring | wheel, and the said nut is good to be connected with the said inner ring | wheel by the fastening using the said attachment bolt. If the nut is connected to the inner ring by bolt fastening in this way, when changing the output side part, the output side part having different specifications can be connected to the inner ring using the female thread portion of the inner ring.
  For example, when the spacer further interposed between the nut and the inner ring, the nut and the spacer can be connected to the inner ring by the fastening.
  In the present invention, the preload nut that abuts against the outer ring from one side in the axial direction, the preload bolt that is screwed into the preload nut, the stator and the preload bolt inside the preload nut are axially moved in the axial direction. A preload spring that is compressed into a circumferential direction, a locking piece that stops the stator in the circumferential direction and supports the stator in the radial direction, and a fixing bolt that is screwed into the outer ring, and the preloading nut and the locking piece Is preferably fastened to the outer ring by the fixing bolt. By adjusting the compression amount of the preload spring, it is possible to adjust the preload (which becomes a braking force when the stator is stopped) that presses the stator against the inner ring. Since the locking piece prevents the stator from rotating, the inner ring drive by the stator can be realized. Further, if the preloading nut and the locking piece are fastened to the outer ring with a fixing bolt, the axial position of the stator is determined in a predetermined manner via the preloading spring and the preloading bolt, and the radial position of the stator is also set by the locking piece. It can be determined in advance. In other words, the stator can be connected to the outer ring only by the detent and preload structure essential for the composite vibrator type stator.
  According to the present invention, by adopting the above configuration, it is possible to cope with the change of the feed screw by changing only the output side component connected to the inner ring. Therefore, it is possible to provide a positioning device that can easily cope with the change of the feed screw. .
1 is a longitudinal front view showing the overall configuration of the positioning device according to the first embodiment. Partial sectional view taken along line II-II in FIG. Longitudinal front view showing an example in which the lead screw in FIG. 1 is changed to a ball screw
  A first embodiment as an example of the present invention will be described below with reference to FIGS. 1 and 2 of the accompanying drawings.
  The positioning device according to the first embodiment includes a screw shaft 10, a nut 20, a rolling bearing 30, a composite vibrator type stator 40, a preload connection means 50, and a rotation sensor 60.
  The screw shaft 10 and the nut 20 function as a feed screw that converts the relative rotational motion of the nut 20 with respect to the screw shaft 10 into the relative linear motion of the nut 20 with respect to the screw shaft 10. The direction along the central axis of the screw shaft 10 corresponds to the “axial direction”, and the direction perpendicular to the axial direction corresponds to the “radial direction”.
  The screw shaft 10 is a male screw part in which a JIS-standard metric trapezoidal screw is formed on the outer periphery. The nut 20 is a female screw part in which a trapezoidal screw corresponding to the screw shaft 10 is formed on the inner periphery. The screw shaft 10 and the nut 20 are provided as slide screws that are directly screwed together with each other's trapezoidal screws.
  The rolling bearing 30 includes an inner ring 31 connected to the nut 20, an outer ring 32 surrounding the inner ring 31, and a plurality of rolling elements 33 that roll between the inner ring 31 and the outer ring 32. The rolling bearing 30 supports the nut 20 of the aforementioned slide screw in the radial direction and the axial direction.
  The rolling bearing 30 is a cross roller bearing. That is, the rolling element 33 consists of cylindrical rollers. The inner ring 31 and the outer ring 32 are each formed of an annular body that forms a V-groove-shaped track. The inner ring 31 and the outer ring 32 are arranged concentrically. The plurality of rolling elements 33 are interposed between the races of the inner ring 31 and the outer ring 32. These rolling elements 33 are arranged in different directions by 90 ° alternately in the circumferential direction. In this way, the rolling bearing 30 provided as a cross roller bearing incorporates rolling elements 33 made of cylindrical rollers between the inner and outer rings 31 and 32 in an orthogonal arrangement. Since it is possible to simultaneously receive loads in various directions such as radial loads and moment loads, it is possible to achieve compactness. As a result, the positioning device can be made compact.
  The inner ring 31 is fitted in a first bearing seat portion 20 a formed on the nut 20. The first bearing seat portion 20 a is formed on the outer periphery of the end portion on one axial side of the nut 20. By fitting the inner ring 31 to the first bearing seat portion 20a from the one axial side to the other axial side, the axial position and radial position of the inner ring 31 with respect to the nut 20 can be provisionally determined. ing.
  Note that a cage or a separator can be appropriately employed as means (not shown) for maintaining the circumferential interval of the rolling elements 33. In consideration of the excellent rigidity, the inner ring 31 and the outer ring 32 are composed of one annular part that forms the entire track. If there is no problem in rigidity, the inner ring 31 and the outer ring 32 may be appropriately changed to a split type ring that forms a track with a plurality of annular parts.
  The stator 40 applies only the rotational driving force to the rotor that is in direct contact with the stator 40 by combining axial vibration and circumferential vibration. The stator 40 is connected to the outer ring 32 by a connection preload means 50.
  The stator 40 includes a stator head 42, a node 43, a first piezoelectric element 44, a second piezoelectric element 45, and a stator bottom 46.
  The hollow bolt 41 is a hollow shaft-shaped male screw component that can be inserted through the screw shaft 10 in the axial direction. The hollow bolt 41 is disposed away from the inner ring 31 toward the one axial side. The stator head 42 protrudes from the hollow bolt 41 to the other side in the axial direction, and is pressed against the side surface of the inner ring 31 from one axial direction to the other axial direction at the protruding end. This pressing is realized by the preload connecting means 50.
  The joint 43 holds the first piezoelectric element 44 in the axial direction together with the stator head 42. The first piezoelectric element 44 vibrates in the axial direction. In addition, the node portion 43 holds the second piezoelectric element 45 in the axial direction together with the stator bottom 46.
  The stator bottom 46 prevents the second piezoelectric element 45 from coming off from the hollow bolt 41. The second piezoelectric element 45 vibrates in the circumferential direction. The first piezoelectric element 44 and the second piezoelectric element 45 are each connected to a power supply device (not shown) that generates a high-frequency current. By applying predetermined alternating voltages to the first piezoelectric element 44 and the second piezoelectric element 45, the vibrations of the first piezoelectric element 44 and the second piezoelectric element 45 are combined and provided from the stator head 42 as a rotor. Only the driving force in the rotational direction is applied to the side surface of the inner ring 31. Thus, when the stator 40 is driven, the node 43 interposed between the first piezoelectric element 44 and the second piezoelectric element 45 becomes a node in the vibration mode. Such a stator 40 is generally called a bolted Langevin type composite vibrator.
  The first piezoelectric element 44 and the second piezoelectric element 45 are each an annular body surrounding the hollow bolt 41. Further, since the stator head 42, the joint 43, and the stator bottom 46 are female screw parts corresponding to the hollow bolt 41, they can be screwed onto the hollow bolt 41. The node 43 may be formed as a part of the hollow bolt 41. Further, another member such as a friction member may be interposed between the inner ring 31 and the stator 40 to drive the inner ring 31 indirectly.
  The preload connecting means 50 connects the stator 40 to the outer ring 32 and presses the stator 40 against the inner ring 31.
  The preload connection means 50 includes a preload nut 51, a preload bolt 52, a preload spring 53, a locking piece 54, and a fixing bolt 55.
  The preload nut 51 is a female screw component that abuts against the side surface of the outer ring 32 from one axial side to the other axial side. The stator head 42 has a spring receiving portion 42 a whose outer diameter is partially enlarged inside the preload nut 51. The preload spring 53 is a coil spring that can be inserted into the annular space between the stator 40 and the preload nut 51. The preload bolt 52 is a male screw component corresponding to the preload nut 51. By inserting the preload spring 53 into the annular space between the stator 40 and the preload nut 51 from the one axial side toward the other axial side, the preload spring 53 comes into contact with the spring receiving portion 42a in the axial direction. In this state, the preloading spring 53 is screwed into the preloading nut 51 and the preloading spring 53 is compressed from one axial side toward the other axial side. Thus, the preload spring 53 compressed in the axial direction by the stator 40 and the preload bolt 52 generates a preload that presses the stator 40 against the side surface of the inner ring 31 from one axial direction to the other axial direction. Yes. In a stopped state of the stator 40 where the first piezoelectric element 44 and the second piezoelectric element 45 do not vibrate, the preload acts as a braking force that stops the inner ring 31. If the compression amount of the preload spring 53 is adjusted by the screwing amount of the preload bolt 52, the preload (braking force) for pressing the stator 40 against the inner ring 31 can be adjusted.
  The fixing bolt 55 is a male screw component corresponding to the first female screw portion 32 a formed on the outer ring 32. The first female thread portion 32a is formed from one axial side to the other axial side. The preload nut 51 and the locking piece 54 are connected to the outer ring 32 by fastening through which the fixing bolt 55 is inserted from the one axial side to the other axial side and screwed into the first female screw portion 32a. In this connected state, the locking piece 54 stops the stator 40 in the circumferential direction and supports it in the radial direction.
  More specifically, the locking piece 54 has a distal end portion 54 a that protrudes in the radial direction toward the node portion 43. The node portion 43 has a distal end portion 54a and a latch receiving portion 43a that can be engaged with both sides in the circumferential direction. As shown in FIGS. 1 and 2, the latch receiving portion 43 a is formed in a groove shape along the axial direction. The outer peripheral portion of the node portion 43 other than the locking receiving portion 43a is arcuately overlapped with the inner peripheral portion of the locking piece 54 in the radial direction. The overlapping region, the locking receiving portion 43a, and the distal end portion 54a are present in the circumferential direction. Due to these overlapping regions, radial support of the stator 40 by the locking pieces 54 is realized. In the composite vibrator type stator 40, the driving force cannot be effectively applied to the inner ring 31 unless the stator 40 is prevented from rotating. For this reason, it is indispensable to prevent the stator 40 from rotating at the node 43 that is the node of the vibration mode in the stator 40.
  When the preload nut 51 and the locking piece 54 are fastened to the outer ring 32 by the fixing bolt 55, the axial position of the stator 40 is determined in a predetermined manner via the preloading spring 53 and the preloading bolt 52, and the locking piece 54 The radial position of the stator 40 can also be predetermined. In other words, the stator 40 can be connected to the outer ring 32 with only the detent and preload structure essential for the stator 40. The fixing bolts 55 are provided at a plurality of locations in the circumferential direction.
  When the stator 40 is connected to the outer ring 32 by the preload connecting means 50 as described above, the stator 40 is placed on one side in the axial direction with the rolling bearing 30 as a boundary. In this state, the inner ring 31 and the hollow bolt 41 are disposed on the same central axis. Since the inner diameter of the bearing hole of the rolling bearing 30 matches the inner diameter of the hollow bolt 41, the outer diameter of the screw shaft 10 can be changed within the range of the inner diameter of the hollow bolt 41. The inner diameter of the bearing hole is the diameter of a cylindrical inner diameter surface formed in the inner ring 31. The inner diameter of the hollow bolt 41 is the diameter of the inner diameter surface formed in a cylindrical shape over the entire axial length of the hollow bolt 41.
  The rotation sensor 60 converts the rotational motion of the inner ring 31 into an output signal. Based on this output signal, voltage application control of the first piezoelectric element 44 and the second piezoelectric element 45 can be performed.
  The rotation sensor 60 includes an encoder 61, an encoder holder 62, a mounting bolt 63, a sensor circuit 64, a sensor holder 65, and a holder fixing bolt 66.
  The encoder 61 is a magnetic encoder having S poles and N poles alternately in the circumferential direction, and converts the rotational movement around the axis into a magnetic physical signal. The encoder 61 is fixed to the encoder holder 62. The encoder holder 62 is an annular part that prevents deformation of the encoder 61.
  The encoder holder 62 is formed with a first bolt through hole 62a penetrating in the axial direction. The inner ring 31 is formed with a female thread portion 31a from the other side in the axial direction toward one side in the axial direction. A second bolt through hole 20b penetrating in the axial direction is formed at the end of the nut 20 on the other side in the axial direction. In a state where the inner ring 31 is fitted to the first bearing seat portion 20a, the second bolt through hole 20b, the female screw portion 31a, and the first bolt through hole 62a communicate in the axial direction. The mounting bolt 63 is a male screw component corresponding to the female screw portion 31a. The nut 20 and the encoder holder 62 are fastened by passing the mounting bolt 63 through the first bolt through hole 62a and the second bolt through hole 20b from the other side in the axial direction toward the one side in the axial direction, and further screwed into the female thread portion 31a. 31 is connected. As a result, the encoder 61, the nut 20, and the inner ring 31 rotate together by driving the inner ring 31 with the stator 40. The mounting bolts 63 are provided at a plurality of locations in the circumferential direction.
  The sensor circuit 64 converts the magnetic physical signal described above into an electrical signal. The sensor circuit 64 has a magnetic sensor mounted on a circuit board. The circuit board is provided with appropriate circuit elements such as a signal processing circuit for adjusting the output of the magnetic sensor to a predetermined output signal, a power supply circuit, and a wiring connection terminal. The sensor circuit 64 is fixed to the sensor holder 65.
  The sensor holder 65 is an annular part that prevents deformation of the sensor circuit 64. The sensor holder 65 is formed with a second bearing seat 65 a that fits into the outer ring 32. By fitting the sensor holder 65 to the second bearing seat 65a from the other side in the axial direction toward one side in the axial direction, it is possible to temporarily determine the axial position and the radial position of the sensor holder 65 with respect to the outer ring 32. It has become.
  The sensor holder 65 is provided with an attachment hole 65b that can be used to attach the positioning device to another device such as a transport device or a lathe. The preload coupling means 50 is set to an outer diameter equal to or smaller than the outer diameter of the outer ring 32 (the bearing outer diameter of the rolling bearing 30), and does not hinder the use of the mounting hole 65b.
  The sensor holder 65 has a third bolt through hole 65c penetrating in the axial direction. The outer ring 32 is formed with a second female thread portion 32b from the other side in the axial direction toward one side in the axial direction. In a state where the outer ring 32 is fitted to the second bearing seat portion 65a, the third bolt through hole 65c and the second female screw portion 32b communicate in the axial direction. The holder fixing bolt 66 is a male screw component corresponding to the second female screw portion 32b. The sensor holder 65 is connected to the outer ring 32 by fastening in which the holder fixing bolt 66 is passed through the third bolt through hole 65c from the other side in the axial direction toward the one side in the axial direction and further screwed into the second female screw portion 32b. Thereby, the sensor circuit 64 can convert the rotational motion of the inner ring 31 relative to the outer ring 32 into an output signal. The holder fixing bolts 66 are provided at a plurality of locations in the circumferential direction. The first female screw portion 32a and the second female screw portion 32b are illustrated as examples in which the outer ring 32 is processed into the inner wall surface of a hole penetrating in the axial direction. .
  As described above, when the encoder 61 and the sensor circuit 64 are connected to the corresponding inner ring 31 and outer ring 32, the encoder 61 and the sensor circuit 64 are arranged on the other side in the axial direction with the rolling bearing 30 as a boundary. In this arrangement state, the nut 20 and the rotation sensor 60 do not protrude from the inner ring 31 and the outer ring 32 to one side in the axial direction, and do not come into contact with the stator 40 or the preload connecting means 50.
  When the encoder 61 and the sensor circuit 64 are connected to the corresponding inner ring 31 and outer ring 32 as described above, the encoder 61 that rotates integrally with the inner ring 31 converts the rotational motion of the inner ring 31 driven by the stator 40 into a physical signal. The sensor circuit 64 integrated with the outer ring 32 stationary with respect to the inner ring 31 can convert the physical signal into an output signal. Therefore, this positioning device controls the first piezoelectric element 44 and the second piezoelectric element 45 of the stator 40 based on the output signal, and can accurately feed the feed screw.
  As described above, when the stator 40 is connected to the outer ring 32 of the rolling bearing 30 by the preload connecting means 50 and the nut 20 is connected to the inner ring 31 by the mounting bolt 63, the stator 40 and the nut 20 are connected via the rolling bearing 30. . For this reason, the driving force of the stator 40 can be applied to the nut 20 via the inner ring 31. That is, the output path between the inner ring 31 and the nut 20 is constituted by the mounting bolt 63 and the fitting surface of the bearing seat 20a and the inner ring 31. On the other hand, the input path between the inner ring 31 and the stator 40 is constituted by the stator head 42 and the side surface on the one axial side of the inner ring 31 and is therefore independent of the aforementioned output path. For this reason, the positioning device according to the first embodiment can change the feed screw (screw shaft 10, nut 20) by changing only the output side component connected to the inner ring 31 without changing the input path and the preload connecting means 50 described above. ).
  FIG. 3 shows an example in which the slide screw in FIG. 1 is changed to a ball screw having a different feed rate. The ball screw shown in FIG. 3 has a ball (not shown) interposed between the screw shaft 70 and the spiral groove of the nut 80 in a circulating manner. For example, the ball screw having the structure disclosed in Patent Document 2 is adopted. Can do. Along with the change to the ball screw, the screw shaft 70 and the nut 80 are reduced in diameter. The rolling bearing 30, the stator 40, and the preload connecting means 50 are not changed from those in FIG.
  In the first embodiment, output side parts having different specifications can be connected to the inner ring 31 using the female thread portion 31 a of the inner ring 31. In the modified example of FIG. 3, the encoder holder 90 is a spacer interposed between the nut 80 and the inner ring 31. The encoder holder 90 is changed to a shape that can maintain the magnetic gap between the encoder 61 and the sensor circuit 64 as in FIG. The nut 80 and the encoder holder (spacer) 90 can be connected to the inner ring 31 by fastening by screwing the mounting bolt 63 into the female thread portion 31 a of the inner ring 31. Thus, according to the first embodiment, it is possible to provide a positioning device that can easily cope with a change in the feed screw. The technical scope of the present invention is not limited to the above-described embodiment, but includes all modifications within the scope of the technical idea based on the description of the scope of claims.
DESCRIPTION OF SYMBOLS 10 Screw shaft 20 Nut 30 Rolling bearing 31 Inner ring 31a Female thread part 32 Outer ring 32a First female thread part 32b Second female thread part 33 Rolling element 40 Stator 41 Hollow bolt 42 Stator head 43 Node 44 First piezoelectric element 45 Second piezoelectric element 46 Stator bottom 50 Preload connection means 51 Preload nut 52 Preload bolt 53 Preload spring 54 Locking piece 55 Fixing bolt 60 Rotating sensor 61 Encoder 62 Encoder holder 63 Mounting bolt 64 Sensor circuit 65 Sensor holder 70 Screw shaft 80 Nut 90 Encoder holder (Spacer)

Claims (6)

  1. The relative rotational movement of the nut with respect to the screw shaft is converted into the relative linear motion of the nut with respect to the screw shaft, and when the nut stops at the target position with respect to the screw shaft, it is held at the position by the braking force. In a possible positioning device,
    A rolling bearing having an inner ring coupled to the nut, an outer ring surrounding the inner ring, and rolling elements that roll between the inner ring and the outer ring;
    A composite vibrator type stator that is connected to the outer ring and applies a driving force to the nut via the inner ring;
    A preload nut that abuts against the outer ring from one side in the axial direction;
    A preload bolt to be screwed into the preload nut;
    A preload spring axially compressed by the stator and the preload bolt inside the preload nut;
    A locking piece for locking the stator in the circumferential direction and supporting the stator in the radial direction;
    A fixing bolt screwed into the outer ring;
    Equipped with a,
    The positioning device according to claim 1, wherein the preload nut and the locking piece are fastened to the outer ring by the fixing bolt .
  2. An encoder connected to the inner ring and converting the rotational movement of the inner ring into a physical signal;
    A sensor circuit connected to the outer ring and converting the physical signal into an output signal;
    Further comprising
    The positioning according to claim 1, wherein the stator is disposed on one axial side with respect to the rolling bearing, and the encoder and the sensor circuit are disposed on the other axial side with respect to the rolling bearing. apparatus.
  3.   The positioning device according to claim 1, wherein the rolling bearing is a cross roller bearing.
  4.   The positioning device according to claim 1, wherein the nut and the screw shaft are a slide screw or a ball screw.
  5. A mounting bolt that is screwed into the inner ring;
    The positioning device according to claim 1, wherein the nut is coupled to the inner ring by fastening using the mounting bolt.
  6. A spacer interposed between the nut and the inner ring;
    The positioning device according to claim 5, wherein the nut and the spacer are connected to the inner ring by the fastening.
JP2014140530A 2014-07-08 2014-07-08 Positioning device Active JP6367025B2 (en)

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JP2014140530A JP6367025B2 (en) 2014-07-08 2014-07-08 Positioning device
PCT/JP2015/069128 WO2016006528A1 (en) 2014-07-08 2015-07-02 Positioning device

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JP2016017570A JP2016017570A (en) 2016-02-01
JP6367025B2 true JP6367025B2 (en) 2018-08-01

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002310174A (en) * 2001-04-18 2002-10-23 Nsk Ltd Bearing with motor
US7893582B2 (en) * 2006-01-31 2011-02-22 Thk Co., Ltd Hollow motor drive device with an offset magnet, shaft, and nut

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JP2016017570A (en) 2016-02-01

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