JP5191829B2 - Linear drive - Google Patents

Description

  The present invention relates to a linear drive device in which an output shaft is driven by a biasing force of a biasing member when power supply to a stator portion is stopped.

  In the valve body drive device, a feed screw mechanism is provided between the rotor of the motor and the output shaft, and a linear drive device that opens and closes the opening in the flow path by directly moving the output shaft is provided. In such a valve body drive device, a configuration is employed in which the output shaft is urged toward the distal end side (closed direction) by an urging member (see Patent Documents 1 and 2).

In such a valve body drive device, a first support portion and a second support portion that support the rotor so as to be rotatable on both sides in the axial direction are configured, and the configuration of such a support portion is described in Patent Document 1. In this valve body drive device, bearing bearings are arranged on the proximal end side and the distal end side of the rotor, and the bearings arranged on the proximal end side of the rotor are moved by a biasing member different from the biasing member described above. A configuration biased toward the tip side is adopted. However, in such a configuration, since the urging forces of the two urging members are applied to the rotor, there is a disadvantage that the motor output has to be increased accordingly. On the other hand, in the valve body drive device described in Patent Document 2, the first support portion disposed on the base end side of the rotor is a sliding bearing having a sliding surface on which the rotor can slide. Since the urging force applied to the rotor is small, the output shaft can be driven smoothly even if the motor output is relatively small.
US2006-0071190A1 Publication JP-A-2005-233203

  However, when the first support portion arranged on the base end side of the rotor is a sliding bearing as in the valve body driving device described in Patent Document 2, the output shaft is moved by the biasing member when power supply to the stator portion is stopped. When driven in the second direction and suddenly stopped at the movement limit position, there is a problem that the male screw and the female screw are bitten in the feed screw mechanism, and the subsequent operation is hindered. That is, when the output shaft driven in the second direction by the urging member when the power supply to the stator portion is stopped suddenly stops at the movement limit position, the rotor rotates by its own inertial force and tries to move in the first direction. However, at that time, if the rotor is in contact with the first support portion and further displacement is prevented, the rotational force due to the inertia of the rotor causes the force that the male screw and the female screw bite in the feed screw mechanism. It will act as.

  In view of the above problems, the problem of the present invention is that even when the output shaft is driven by the urging member when power supply to the stator is stopped and suddenly stops at the movement limit position, biting between screws occurs in the feed screw mechanism. It is to provide a linear drive device that does not.

  In order to solve the above problems, in the present invention, a motor including a stator portion and a rotor, a first support portion that rotatably supports the rotor on a first direction side in the axial direction, and the rotor in the axial direction. A second support part rotatably supported on the second direction side opposite to the first direction side, and connected to the rotor via a feed screw mechanism and linearly driven in the first direction and the second direction And a biasing member that biases the output shaft in the second direction. The first support portion includes a sliding surface on which the rotor can slide. The sliding bearing is configured such that when the power supply to the stator portion is stopped, the output shaft is urged by the urging means to move to the movement limit position in the second direction. Between the first support part and the rotor, When the output shaft suddenly stops at the movement limit position when the power supply is stopped, the rotor is prevented from coming into contact with the first support when the rotor rotates in the inertial force and moves in the first direction. It is characterized in that a clearance is provided.

  In the present invention, since a sufficient clearance is provided between the first support portion and the rotor in the thrust direction, a slide bearing having a sliding surface on which the rotor can slide is used as the first support portion. Even when the power supply to the stator portion is stopped, when the output shaft suddenly stops at the movement limit position, the movement of the rotor rotating in the first direction due to the inertial force is not prevented. For this reason, since the rotational force due to the inertia of the rotor does not act as a force to cause biting in the feed screw mechanism, the output shaft is urged by the urging means at the movement limit position when power supply to the stator portion is stopped. Even when moving until it stops, the feed screw mechanism does not bite.

  In the present invention, the output shaft is formed with a valve body that closes an opening located on the second direction side with respect to the output shaft, and the movement limit position is a position at which the valve body closes the opening. It is.

  In this case, the output shaft suddenly stops at the movement limit position by the valve body coming into contact with the opening forming portion forming the opening and closing the opening.

  In the present invention, since a sufficient clearance is provided between the first support portion and the rotor in the thrust direction, when the output shaft suddenly stops at the movement limit position when power supply to the stator portion is stopped, the rotor is The movement to rotate in the first direction by the inertial force is not prevented. For this reason, since the rotational force due to the inertia of the rotor does not act as a force to cause biting in the feed screw mechanism, the output shaft is urged by the urging means at the movement limit position when power supply to the stator portion is stopped. Even when moving until it stops, the feed screw mechanism does not bite.

  A bearing and a drive device (linear drive device) to which the present invention is applied will be described below with reference to the drawings.

[Embodiment 1]
FIG. 1 is a perspective view showing an external appearance of a valve body drive device (linear drive device) according to Embodiment 1 of the present invention. 2A and 2B are a cross-sectional view of the valve body drive device (linear drive device) according to Embodiment 1 of the present invention and an enlarged cross-sectional view showing an enlarged lower end portion thereof. 1 and 2, the lower side is shown as the valve body opening direction (first direction) and the upper side is shown as the valve body closing direction (second direction). The opening direction of the body and the upper direction are the closing direction of the valve body. However, the posture in which the valve body driving device 1 is arranged is not limited to the above setting. Of course, there is also an aspect of the body opening direction, an aspect in which the right side is the closing direction of the valve body, and the left side is the opening direction of the valve body.

  A valve body drive device 1 (shutoff valve / linear drive device) shown in FIGS. 1 and 2 (a) and 2 (b) has an opening (not shown) formed in a flow path of gas or the like downstream of the flow path. In the case of an emergency such as a power failure, the opening is forcibly closed by a spring force, and the opening of the stepping motor 2 is closed by a cup-shaped partition member 3. The first space 1s in which the portion 20 is disposed is partitioned into a second space 1t on the flow path side in which the rotor 50, the valve body 85, and the like of the stepping motor 2 are disposed.

  The partition member 3 includes a cylindrical partition wall portion 33 having a bottom and an annular flange portion 31 whose diameter is enlarged at the opening edge of the cylindrical partition wall portion 33. A cylindrical stator portion 20 of the motor 2 is arranged concentrically. An annular step portion 335 is formed in the cylindrical partition wall portion 33, and the position in the axial direction L of the stator portion 20 is defined by the step portion 335. The partition member 3 is formed by performing deep drawing or the like on a thin nonmagnetic metal plate.

  The stator part 20 has a pair of stator sets 21 and 22 arranged so as to overlap in the axial direction L. Each of the stator sets 21 and 22 is an annular coil wound around an insulator, and the axial direction of the coil. A pair of stator cores disposed on both sides of L are provided. Each of the pair of stator cores includes a large number of pole teeth standing up along the inner peripheral surface of the coil, and the pole teeth formed on the pair of stator cores are alternately arranged in the circumferential direction in a state where the stator assembly 21 is configured. It will be in the state arranged in. A terminal block 26 is formed on the side surface of the stator unit 20, and a plurality of terminals 27 are fixed to the terminal block 26. A connector portion 28 is formed so as to cover the terminal block 26.

  On the inner side of the cylindrical partition wall 33 of the partition member 3, there are a bearing member 6 (first support portion), a cylindrical rotor 50, a disk-shaped bearing bearing 9 (second support portion), and a cylindrical support member 4. Half portions are arranged in this order, and an output shaft 8 extending in the axial direction L is arranged inside the rotor 50, the bearing bearing 9, and the cylindrical support member 4.

  Among these members, the rotor 50 rotates around the axis, and the output shaft 8 moves in the axial direction L. On the other hand, the bearing member 6, the stator part 20, and the cylindrical support member 4 are connected via the partition member 3, and constitute the fixed body 1a.

  The upper end portion of the output shaft 8 passes through a hole 49 formed in the upper bottom portion of the cylindrical support member 4, and a valve body 85 having a diameter larger than that of the output shaft 8 is attached to the upper end portion. The valve body 85 is completely fixed to the upper end portion of the output shaft 8, and the valve body 85 and the output shaft 8 are integrated. A circumferential groove is formed on the side surface of the valve body 85, and a seal member 86 made of a rubber O-ring or the like is attached to the circumferential groove. The valve body 85 closes the opening of the flow path by coming into contact with the opening forming portion of the flow path.

  A coil spring 5 as an urging member is mounted around the cylindrical support member 4. The coil spring 5 has a flange portion 851 formed at both ends on the proximal end side of the valve body 85 and a cylindrical portion. It supports in the state compressed between the step parts 45 formed in the outer peripheral surface of the shaped support member 4. FIG. The cylindrical support member 4 is pressed against the annular step portion 335 of the partition member 3 by an elastic retaining ring 35, and the cylindrical support member 4 is attached to the partition member 3 in a state where movement in the axial direction L and rotation around the axis line are restricted. It is fixed.

  The bearing member 6 has a shape in which a bottomed cylindrical portion 62 protrudes downward from the disc-shaped flange portion 61, and the outer peripheral surface of the disc-shaped flange portion 61 is within the cylindrical partition wall portion 33 of the partition member 3. The lower end portion of the cylindrical portion 62 of the bearing member 6 is in contact with the peripheral surface, and is in contact with the bottom portion 332 of the cylindrical partition wall portion 33 of the partition member 3. In the bearing member 6, an annular groove 66 is formed on the lower surface of the disc-shaped flange portion 61 so as to surround the cylindrical portion 62, and the annular groove 66 provides elasticity to the outer peripheral portion of the disc-shaped flange portion 61. Has been granted. For this reason, the outer peripheral surface of the disk-shaped flange portion 61 abuts on the cylindrical partition wall 33 of the partition member 3 with elasticity, and the bearing member 6 is fixed to the bottom of the cylindrical partition wall 33 of the partition member 3. . In the bearing member 6, the hole of the cylindrical portion 62 constitutes a shaft hole 65 that opens at the center of the upper surface of the disk-like flange portion 61.

  The rotor 50 has a bottomed cylindrical rotor member 51, and a rotor magnet 52 is fixed to the outer peripheral surface thereof. On the outer peripheral surface of the rotor magnet 52, the S pole and the N pole are alternately arranged in the circumferential direction, and the outer peripheral surface is opposed to the inner peripheral surface of the stator portion 20 via the cylindrical partition wall portion 33 of the partition member 3. doing. A round bar-like projection 55 projects downward from the lower end surface 510 of the rotor member 51, and the projection 55 is fitted in the shaft hole 65 of the bearing member 6. In this state, the rotor 50 is rotatably supported by the shaft hole 65 of the bearing member 6 through the protrusion 55.

  Accordingly, the bearing member 6 is a sliding bearing having a thrust bearing function and a radial bearing function for the rotor 50, and the inner bottom surface of the shaft hole 65 (the bottom surface of the cylindrical portion 62) of the bearing member 6 is the protrusion 55 of the rotor 50. The inner peripheral surface of the shaft hole 65 of the bearing member 6 functions as a sliding surface that supports the outer peripheral surface of the protrusion 55 of the rotor 50.

  Here, a clearance d <b> 1 described later is provided between the inner bottom surface of the shaft hole 65 of the bearing member 6 (the bottom surface of the cylindrical portion 62) and the lower end surface of the protrusion 55 of the rotor 50. A clearance d2 described later is provided between the end surface 510 and the upper surface of the disk portion 61 of the bearing member 6.

  Small holes 57 and 670 communicating with each other are formed in the protrusion 55 of the rotor member 51 and the bottom portion 67 of the cylindrical portion 62 of the bearing member 6. The small holes 57 and 670 are formed in the cylindrical partition wall 33 of the partition member 3. This is a hole for venting air when the bearing member 6 is arranged at the bottom of the.

  The rotor 50 has a cylindrical shape that opens upward, and the lower half of the output shaft 8 is inserted inside the rotor 50. Here, a female screw 58 for a feed screw mechanism is formed on the inner peripheral surface of the rotor member 51, while a male screw 88 for a feed screw mechanism is formed on a portion of the output shaft 8 inserted inside the rotor 50. The male screw 88 of the output shaft 8 meshes with the female screw 58 of the rotor member 51. Further, the hole 49 formed in the upper plate portion of the cylindrical support member 4 has a D shape, while the upper half portion of the output shaft 8 including the portion located inside the hole 49 has a D shape. Yes. For this reason, when the rotor 50 rotates, the output shaft 8 also tries to rotate. However, the engagement portion between the output shaft 8 and the hole 49 of the cylindrical support member 4 functions as a co-rotation preventing mechanism. Cannot rotate. For this reason, when the rotor 50 rotates, the output shaft 8 moves in the axial direction L without rotating together with the rotor 50. In this way, in this embodiment, the rotation / linear motion conversion mechanism 1d that converts the rotation of the rotor 50 into the linear motion of the output shaft 8 is configured.

(Detailed configuration of bearing 9)
FIGS. 3A and 3B are a perspective view and a cross-sectional view, respectively, of a bearing bearing 9 used in the valve body drive device (linear drive device) according to Embodiment 1 of the present invention. In FIG. 3A, the retainer is indicated by a one-dot chain line, and in FIG. 3B, the retainer is not shown.

  A bearing 9 shown in FIGS. 2 (a), 3 (a), and 3 (b) is a thrust bearing in which at least one is disposed between a first member and a second member that rotate about an axis, An annular first support plate 91 disposed on one member side (rotor member 51 side / rotating member side) and a second member side (cylindrical shape) so as to face the first support plate 91 in the axial direction L. And an annular second support plate 92 disposed on the support member 4 side / fixed body 1a side. An annular rolling path 95 is formed between the first support plate 91 and the second support plate 92, and a plurality of bearing balls 93 held by the annular retainer 94 are provided in the rolling path 95, It arrange | positions so that the rolling path 95 may be followed. In this embodiment, the first support plate 91 is held on the rotor member 51 side, the second support plate 92 is held on the cylindrical support member 4 side, and the output shaft 8 includes the first support plate 91 and The lower half is located inside the rotor 50 through a hole formed in the center of the second support plate 92. In this embodiment, both the first support plate 91 and the second support plate 92 are made of SUS.

  In this bearing bearing 9, in this embodiment, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 is an inclined surface inclined in the axial direction L on the side (upward) where the bearing ball 93 is located. The first annular surface 910 is a conical surface. Further, the second annular surface 920 constituting the rolling path 95 in the second support plate 92 is an inclined surface inclined in the opposite side (upward) to the side where the bearing ball 93 is positioned in the axial direction L, The second annular surface 920 is a conical surface. Thus, both the first annular surface 910 and the second annular surface 920 are conical surfaces that are inclined obliquely in the same direction with respect to the axial direction L.

  Here, the inclinations of the first annular surface 910 and the second annular surface 920 are equal, and the first annular surface 910 and the second annular surface 920 are parallel. For this reason, the facing distance (width dimension of the rolling path 95) between the first annular surface 910 and the second annular surface 920 is the same from the inner peripheral side toward the outer peripheral side. Further, the first annular surface 910 and the second annular surface 920 are continuous surfaces having no bent portion from the inner peripheral side to the outer peripheral side. For this reason, the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at one location.

(Operation)
In the valve body drive device 1 of the present embodiment, the valve body 85 and the output shaft 8 are positioned above during the period in which the valve body 85 closes the opening of the flow path. In order to move the valve body 85 in the opening direction (downward / first direction) in this state, power is supplied to the stator unit 20 and the rotor 50 is rotated forward. As a result, the output shaft 8 is driven by a feed screw mechanism including a female screw 58 and a male screw 88 and moves downward against the urging force of the coil spring 5, so that the valve body 85 opens the flow path. And Such an open state is maintained by a holding force acting between the rotor 50 and the stator.

  In such an open state, when a gas shutoff command is issued when the gas flow rate is abnormal or an earthquake occurs, a driving signal for rotating the rotor 50 in reverse is applied to the stator unit 20, and the output shaft 8 is connected to the female screw 58 and the male screw. Driven by a feed screw mechanism including a screw 88 and driven in a closing direction (upward / second direction), the valve body 85 stops in a state where the opening of the flow path is closed.

  Further, when the signal supply to the stator unit 20 is stopped while the valve body 85 and the output shaft 8 are being driven in the closing direction, the output shaft 8 is closed (upward / second direction) by the urging force of the coil spring 5. ), The valve body 85 comes into contact with the opening forming portion of the flow path and stops suddenly with the opening closed.

(Clearing between bearing member 6 and rotor 50 in the thrust direction)
In the valve body drive device 1 of this embodiment, when the signal supply to the stator unit 20 is stopped while the valve body 85 and the output shaft 8 are being driven in the closing direction, the output shaft 8 is driven by the biasing force of the coil spring 5. It moves in the closing direction (upward / second direction), and the valve body 85 suddenly stops with the opening of the flow path closed. At that time, the rotor 50 is rotated by its own inertial force and tends to move downward (first direction).

  In consideration of such an operation, in this embodiment, first, the clearance d1 between the inner bottom surface of the shaft hole 65 (the bottom surface of the cylindrical portion 62) of the bearing member 6 and the lower end surface of the protrusion 55 of the rotor 50 is the stator portion. When power supply to 20 is stopped, the rotor 50 rotates with inertial force when the output shaft 8 moved in the closing direction (upward / second direction) by the biasing force of the coil spring 5 suddenly stops at the movement limit position. Even when moved in the first direction, the dimensions are sufficient to avoid contact between the inner bottom surface of the shaft hole 65 of the bearing member 6 (the bottom surface of the cylindrical portion 62) and the lower end surface of the protrusion 55 of the rotor 50. Is set to

  Similarly to the clearance d1, the clearance d2 between the lower end surface 510 of the rotor member 51 and the upper surface of the disk portion 61 of the bearing member 6 is also affected by the biasing force of the coil spring 5 when power supply to the stator portion 20 is stopped. Even when the rotor 50 rotates in the inertial force and moves in the first direction when the output shaft 8 that has moved in the closing direction (upward / second direction) suddenly stops at the movement limit position, the rotor member 51 moves. The dimension is set to be sufficient to avoid contact between the lower end surface 510 and the upper surface of the disk portion 61 of the bearing member 6.

(Main effects of this form)
As described above, in the valve body drive device 1 of the present embodiment, the bearing member 6 disposed as the first support portion on the base end side (first direction) of the rotor 50 has a sliding surface on which the rotor 50 can slide. Therefore, the biasing force applied to the rotor 50 is small. Therefore, the output shaft 8 can be smoothly driven even if the motor output is relatively small.

  Further, when the bearing member 6 is a sliding bearing, the position in the axial direction L is fixed. Therefore, when the power supply to the stator portion 20 is stopped, the output shaft 8 is directed in the opening direction (upward / second direction) by the coil spring 5. When the rotor 50 is suddenly stopped at the movement limit position, the bearing member 6 prevents the rotor 50 from rotating by its own inertial force and moving downward. In this embodiment, Since the clearances d1 and d2 between the bearing member 6 and the rotor 50 in the thrust direction are sufficiently wide, the downward movement of the rotor 50 when the power supply is stopped is not prevented. For this reason, even when the output shaft 8 suddenly stops at the movement limit position, the rotor 50 continues to rotate for a while without causing biting between the male screw 88 and the female screw 58 constituting the feed screw mechanism. . Therefore, since the rotational force due to the inertia of the rotor 50 does not act as a force for the male screw 88 and the female screw 58 constituting the feed screw mechanism to bite, the valve body driving device 1 is highly reliable in operation.

  Further, the bearing bearing 9 used in the valve body driving device 1 of the present embodiment has a bearing ball in a rolling path 95 formed between the first support plate 91 and the second support plate 92 facing each other in the axial direction L. 93 is disposed and can be used as a thrust bearing. Here, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 and the second annular surface 920 constituting the rolling path 95 in the second support plate 92 are both outer circumferences from the inner circumference side. The bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at one location because it is a continuous surface that does not have a bent portion on the side. For this reason, the bearing ball 93 rolls in a state in which the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at only one location, and therefore, sliding loss is small.

  Further, since the first annular surface 910 is inclined to the side where the bearing ball 93 is located, even if the bearing ball 93 is subjected to centrifugal force when it rolls, the displacement of the bearing ball 93 toward the outer peripheral side is the first annular surface. Blocked by face 910. Therefore, the track of the bearing ball 93 on which the bearing ball 93 rolls is stable. Even when the bearing ball 93 rolls and receives a centrifugal force, the displacement toward the outer peripheral side is prevented by the first annular surface 910, so that the bearing ball 93 does not fall off the retainer 94.

  In the present embodiment, in the valve body driving device 1, when the power supply to the stepping motor 2 is stopped, the rotor member 51 that rotates following the output shaft 8 that moves by the biasing force of the coil spring 5, and the fixed body 1a Since the bearing bearing 9 is disposed between them, the output shaft 8 can be smoothly driven by the coil spring 5, and a small and inexpensive stepping motor 2 can be used. That is, in the valve body drive device 1 of this embodiment, the coil spring 5 reliably moves the output shaft 8 in the closing direction even if the biasing force of the coil spring 5 is small because the sliding loss at the bearing 9 is small. Can do. Further, when the output shaft 8 is moved in the opening direction by driving the stepping motor 2, it will resist the urging force of the coil spring 5. Therefore, if the urging force of the coil spring 5 is small, the motor output can be reduced accordingly. As the stepping motor 2, a small and inexpensive one can be used.

[Embodiment 2]
FIG. 4 is a cross-sectional view of a bearing bearing 9 used in the valve body drive device (linear drive device) according to Embodiment 2 of the present invention, and the retainer is not shown in FIG. Since the basic configuration of this embodiment is the same as that of Embodiment 1, detailed description of common parts is omitted.

  As shown in FIG. 4, in the bearing bearing 9 of the present embodiment as well, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 has the bearing ball 93 in the axial direction L as in the first embodiment. The first annular surface 910 is a conical surface. Further, the second annular surface 920 constituting the rolling path 95 in the second support plate 92 is an inclined surface inclined in the opposite side (upward) to the side where the bearing ball 93 is positioned in the axial direction L, The second annular surface 920 is a conical surface. Thus, both the first annular surface 910 and the second annular surface 920 are conical surfaces that are inclined obliquely in the same direction with respect to the axial direction L.

  Here, when the inclinations of the first annular surface 910 and the second annular surface 920 are compared, the first annular surface 910 is inclined more greatly than the second annular surface 920, and the first annular surface 910 and the second annular surface 920 Are non-parallel. For this reason, the opposing distance (the width dimension of the rolling path 95) between the first annular surface 910 and the second annular surface 920 is continuously narrowed from the inner peripheral side toward the outer peripheral side. Further, the first annular surface 910 and the second annular surface 920 are continuous surfaces having no bent portion from the inner peripheral side to the outer peripheral side. For this reason, the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at one location.

  Even in such a configuration, the bearing ball 93 rolls in a state in which the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at only one location, and therefore, the sliding loss is small. The first annular surface 910 is inclined to the side where the bearing ball 93 is located, and the opposing distance between the first annular surface 910 and the second annular surface 920 is continuously from the inner peripheral side toward the outer peripheral side. It is narrower. For this reason, the bearing ball 93 rolls in a state in which the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at only one location, and therefore, sliding loss is small.

  Further, the rolling path 95 has a smaller separation distance between the first annular surface 910 and the second annular surface 920 as it goes to the outer peripheral side, so even if it receives a centrifugal force when the bearing ball 93 rolls, Displacement toward the outer peripheral side is prevented by the first annular surface 910 and the second annular surface 920. Therefore, the track of the bearing ball 93 on which the bearing ball 93 rolls is stable. Even if the bearing ball 93 rolls and receives a centrifugal force, the displacement to the outer peripheral side is prevented by the first annular surface 910 and the second annular surface 920, so the bearing ball 93 falls off the retainer. There is nothing.

[Embodiment 3]
FIG. 5 is a cross-sectional view of the bearing bearing 9 used in the valve body drive device (linear drive device) according to Embodiment 2 of the present invention. In FIG. 5, the retainer is not shown. Since the basic configuration of this embodiment is the same as that of Embodiment 1, detailed description of common parts is omitted.

  As shown in FIG. 5, in the bearing bearing 9 of the present embodiment as well, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 has a bearing ball 93 in the axial direction L as in the first embodiment. The first annular surface 910 is a conical surface. Further, the second annular surface 920 constituting the rolling path 95 in the second support plate 92 is an inclined surface inclined in the opposite side (upward) to the side where the bearing ball 93 is positioned in the axial direction L, The second annular surface 920 is a conical surface. Thus, both the first annular surface 910 and the second annular surface 920 are conical surfaces that are inclined obliquely in the same direction with respect to the axial direction L.

  Here, when the inclinations of the first annular surface 910 and the second annular surface 920 are compared, the second annular surface 920 is inclined more greatly than the first annular surface 910, and the first annular surface 910, the second annular surface 920, Are non-parallel. For this reason, the facing distance (width dimension of the rolling path 95) between the first annular surface 910 and the second annular surface 920 is continuously increased from the inner peripheral side toward the outer peripheral side. Further, the first annular surface 910 and the second annular surface 920 are continuous surfaces having no bent portion from the inner peripheral side to the outer peripheral side. For this reason, the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at one location.

  Even in such a configuration, the bearing ball 93 rolls in a state in which the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at only one location, and therefore, the sliding loss is small. In addition, since the first annular surface 910 is inclined to the side where the bearing ball 93 is located, even if a centrifugal force is applied when the bearing ball 93 rolls, displacement to the outer peripheral side is prevented by the first annular surface 910. Is done. Therefore, the track of the bearing ball 93 on which the bearing ball 93 rolls is stable. Even when the bearing ball 93 rolls and receives a centrifugal force, the displacement to the outer peripheral side is prevented by the first annular surface 910, so that the bearing ball 93 does not fall off the retainer.

[Embodiment 4]
FIG. 6 is a cross-sectional view of a bearing bearing 9 used in a valve body drive device (linear drive device) according to Embodiment 4 of the present invention. In FIG. 6, the retainer is not shown. Since the basic configuration of this embodiment is the same as that of Embodiment 1, detailed description of common parts is omitted.

  As shown in FIG. 6, in the bearing bearing 9 of this embodiment, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 has a bearing ball 93 in the axial direction L as in the first embodiment. The first annular surface 910 is a conical surface.

  On the other hand, the second annular surface 920 constituting the rolling path 95 in the second support plate 92 is a surface orthogonal to the axial direction L. For this reason, the opposing distance (the width dimension of the rolling path 95) between the first annular surface 910 and the second annular surface 920 is continuously narrowed from the inner peripheral side toward the outer peripheral side. Further, the first annular surface 910 and the second annular surface 920 are continuous surfaces having no bent portion from the inner peripheral side to the outer peripheral side. For this reason, the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at one location.

  Even in such a configuration, the bearing ball 93 rolls in a state in which the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at only one location, and therefore, the sliding loss is small. In addition, since the first annular surface 910 is inclined to the side where the bearing ball 93 is located, even if a centrifugal force is applied when the bearing ball 93 rolls, displacement to the outer peripheral side is prevented by the first annular surface 910. Is done. Therefore, the track of the bearing ball 93 on which the bearing ball 93 rolls is stable. Even when the bearing ball 93 rolls and receives a centrifugal force, the displacement to the outer peripheral side is prevented by the first annular surface 910, so that the bearing ball 93 does not fall off the retainer.

[Embodiment 5]
FIG. 7 is a cross-sectional view of a bearing bearing 9 used in the valve body drive device (linear drive device) according to Embodiment 5 of the present invention, and the retainer is not shown in FIG. Since the basic configuration of this embodiment is the same as that of Embodiment 1, detailed description of common parts is omitted.

  As shown in FIG. 7, the bearing bearing 9 of this embodiment also has a bearing ball 93 in the axial direction L on the second annular surface 920 constituting the rolling path 95 in the second support plate 92, as in the first embodiment. The second annular surface 920 is a conical surface.

  On the other hand, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 is a surface orthogonal to the axial direction L. For this reason, the opposing distance (the width dimension of the rolling path 95) between the first annular surface 910 and the second annular surface 920 continuously extends from the inner peripheral side toward the outer peripheral side. Further, the first annular surface 910 and the second annular surface 920 are continuous surfaces having no bent portion from the inner peripheral side to the outer peripheral side. For this reason, the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at one location.

  Even in such a configuration, the bearing ball 93 rolls in a state where it is in contact with each of the first annular surface 910 and the second annular surface 920 at only one place, and thus there is an effect that the sliding loss is small. .

  In addition, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 is an inclined surface inclined in the opposite direction (downward) to the side where the bearing ball 93 is positioned in the axial direction L. (2) Adopting a structure in which the second annular surface 920 constituting the rolling path 95 in the support plate 92 is an inclined surface inclined in the opposite direction (upward) to the side where the bearing ball 93 is positioned in the axial direction L. Also good.

[Embodiment 6]
FIG. 8 is a cross-sectional view of the bearing bearing 9 used in the valve body drive device (linear drive device) according to Embodiment 6 of the present invention, and the retainer is not shown in FIG. Since the basic configuration of this embodiment is the same as that of Embodiment 1, detailed description of common parts is omitted.

  As shown in FIG. 8, in the bearing bearing 9 of this embodiment, the first annular surface 910 constituting the rolling path 95 in the first support plate 91 is a surface orthogonal to the axial direction L. Further, the second annular surface 920 constituting the rolling path 95 in the second support plate 92 is also a surface orthogonal to the axial direction L. For this reason, the 1st annular surface 91 and the 2nd annular surface 920 are parallel, and the opposing distance (width dimension of rolling path 95) of the 1st annular surface 910 and the 2nd annular surface 920 is from the inner circumference side. Constant toward the outer periphery. Further, the first annular surface 910 and the second annular surface 920 are continuous surfaces having no bent portion from the inner peripheral side to the outer peripheral side. For this reason, the bearing ball 93 is in contact with each of the first annular surface 910 and the second annular surface 920 at one location. Even in such a configuration, the bearing ball 93 rolls in a state where it is in contact with each of the first annular surface 910 and the second annular surface 920 at only one place, and thus there is an effect that the sliding loss is small. .

[Other application examples]
In the said embodiment, you may apply the structure regarding the clearance between the bearing member 6 and the rotor 50 which were employ | adopted by this invention not only to said valve body drive device 1 but another linear drive device.

It is a perspective view which shows the external appearance of the valve body drive device (linear drive device) which concerns on Embodiment 1 of this invention. (A), (b) is sectional drawing of the valve body drive device (linear drive device) which concerns on Embodiment 1 of this invention, respectively, and an expanded sectional view which expands and shows the lower end part. (A), (b) is the perspective view and sectional drawing of a bearing which were used for the valve body drive device (linear drive device) which concerns on Embodiment 1 of this invention, respectively. It is sectional drawing of the bearing used for the valve body drive device (linear drive device) concerning Embodiment 2 of this invention. It is sectional drawing of the bearing used for the valve body drive device (linear drive device) which concerns on Embodiment 3 of this invention. It is sectional drawing of the bearing used for the valve body drive device (linear drive device) concerning Embodiment 4 of this invention. It is sectional drawing of the bearing used for the valve body drive device (linear drive device) which concerns on Embodiment 5 of this invention. It is sectional drawing of the bearing used for the valve body drive device (linear drive device) concerning Embodiment 6 of this invention.

Explanation of symbols

1 Valve body drive device (shutoff valve / linear drive device)
2 Stepping motor (motor)
3 Partition member 5 Coil spring (biasing member)
6 Bearing member 8 Output shaft 9 Bearing bearing 20 Stator portion 50 Rotor 55 Rotor protrusion 58 Female screw 65 Bearing member shaft hole 85 Valve body 88 Male screw

Claims (3)

A motor including a stator portion and a rotor; a first support portion that rotatably supports the rotor on a first direction side in an axial direction; and a second that is opposite to the first direction side in the axial direction. A second support portion rotatably supported on the direction side, an output shaft connected to the rotor via a feed screw mechanism and linearly driven in the first direction and the second direction, and the output shaft being the first A linear drive device having a biasing member biasing in two directions;
The first support portion is a sliding bearing having a sliding surface on which the rotor can slide,
When the power supply to the stator portion is stopped, the output shaft is urged by the urging means to move to the movement limit position in the second direction,
Between the first support portion and the rotor in the thrust direction, when the output shaft suddenly stops at the movement limit position when the power supply is stopped, the rotor rotates in an inertial force and moves in the first direction. A linear drive device is provided, wherein a clearance is provided to prevent the rotor from coming into contact with the first support portion when the contact is made. The output shaft is formed with a valve body that closes an opening located on the second direction side with respect to the output shaft,
The linear drive device according to claim 1, wherein the movement limit position is a position where the valve body closes the opening.   3. The linear drive device according to claim 2, wherein the output shaft suddenly stops at the movement limit position when the valve body abuts on an opening forming portion that forms the opening and closes the opening. 4. .

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