JP2008082902A - Divided type pulley, and torque measuring device of motor using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a divided type pulley that is fixed reliably even if a shaft to be mounted is short, and to provide a torque measuring device of a motor using the divided type pulley. <P>SOLUTION: A pulley outer frame body 21, a spacer 22, and a screw 23 compose the divided type pulley. In the pulley outer frame body 21, two splits 21a, 21b divided equally in a radial direction coalesce mutually. The spacer 22 forms a cylindrical shape, and collar sections 22a, 22b pushed out the outside in the radial direction are formed integrally at the upper- and lower-end sections. The collar sections 22a, 22b come into contact with an upper end face of the pulley outer frame body 21, and a step section 28 provided at one portion of the inner wall, respectively, thus clamping one portion in the thickness direction of the pulley outer frame body 21 between the collar sections 22a, 22b. When tightening the pulley outer frame body 21 with the screw 23, a gap 27 provided between the inner-periphery surface of the pulley outer frame body 21 and the outer-periphery surface of the spacer 22 operates as a clamping margin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a split pulley and a motor torque measuring device using the same.

  2. Description of the Related Art Conventionally, a so-called split type pulley that is divided into a plurality of parts in the radial direction is known as a pulley that is attached to a rotating shaft of a motor or the like. 3A and 3B are diagrams showing a conventional split pulley, and FIG. 3A is a top view, and FIG. 3B is a cross-sectional view taken along line AA ′ of FIG. It is divided in the thickness direction along the axis, and is divided into two in the radial direction, the pulley half 1a and the pulley half 1b. The pulley halves 1a and 1b are provided with a substantially semicircular cutout 2 that engages with a rotating shaft (shaft) of a motor to be attached, and the outer peripheral surface generally has a wire for winding a wire. A semicircular groove 3 is provided.

  Further, a through hole 4a that penetrates the inside in the radial direction is provided on the side surface of the pulley half body 1a, and on the inner circumferential surface at a position facing the through hole 4a on the side surface of the pulley half body 1b. A threaded hole 4b in which a thread groove is formed is formed.

  A screw 5 for fastening the two pulley halves 1a and 1b to each other is inserted into a through hole 4a provided in the pulley half 1a, and the tip of the screw 5b is provided in the pulley half 1b. Thus, the pulley halves 1a and 1b are fastened in a direction close to each other via a predetermined tightening allowance (gap) 6 and integrated as one pulley. (For example, see Patent Documents 1 and 2)

  FIG. 4 is a cross-sectional view schematically showing a state in which a conventional split type pulley is attached to a rotating shaft of a motor, (a) a state in which a split type pulley is attached to a motor having a relatively long rotating shaft, and (b) rotation. It shows a state where a split pulley is attached to a motor with a relatively short shaft. When attaching the split type pulley to the rotation shaft of the motor, as shown in FIG. 4A, when the rotation shaft 7a of the motor 7 is relatively long (for example, when the length of the rotation shaft is greater than the thickness of the pulley). In the split pulley 1, the longitudinal direction of the rotating shaft 7a of the motor 7 is clamped in a wide range. However, in a low-profile spindle motor or the like as shown in FIG. Since the split pulley 1 is relatively short, the rotary shaft 7a is held only by its lower end.

The split pulley is attached to the rotation shaft of the motor, and is used as a joint for transmitting the rotation force of the motor to another drive mechanism or torque measuring device via a wire. FIG. 5 is a cross-sectional view schematically showing a motor torque measuring device using a split pulley. In this way, the split pulley 1 is attached to the rotating shaft 7a of the motor 7, and the rotational force is transmitted to the outer periphery thereof. The wire 8 is wound and one end or both ends (both ends here) of the wire 8 are connected to the torque detector 9. When the motor 7 rotates, the rotational force of the motor 7 is transmitted to the torque detector 9 via the wire 8 wound around the split pulley 1, and the torque is measured. (For example, see Patent Documents 3 and 4)
JP-A-57-151593 JP 2003-314668 A Japanese Patent Laid-Open No. 5-149803 JP 2003-35616 A

  As shown in FIG. 4A, when the rotation shaft of the motor to which the split pulley is attached is relatively long, the contact area between the inner surface of each pulley half of the split pulley and the rotary shaft However, when the pulley rotation axis is relatively short as shown in FIG. 4 (b), the split type pulley has only the lower end portion of the rotation shaft. Therefore, a stable fastening force cannot be obtained with respect to the rotating shaft, the pulley itself may be tilted or distorted, and the pulley may fall off during rotation, and the rotation will be unstable until it does not fall off. There was a risk of becoming.

  To solve this problem, it is possible to reduce the size of the pulley by reducing the thickness of the pulley itself according to the length of the rotating shaft of the motor. However, such a small pulley is difficult to design and can be attached and detached. There is a problem that handling is bad, such as being difficult.

  The present invention has been made in view of the various problems as described above, and has a split pulley that is excellent in handleability and can be securely fixed to a shaft to be attached, and the same. An object of the present invention is to provide a motor torque measuring device.

  A split-type pulley that fastens a plurality of divided bodies divided in the radial direction with screws and fixes them to a shaft to be attached. At least a plurality of divided bodies that are divided in the radial direction are combined to form a pulley. A cylindrical pulley that is configured as a member, has a groove that engages with a wire on the outer peripheral surface, and has a through hole that penetrates the inside in a radial direction and a screw hole that is disposed at a position facing the through hole. An outer frame body and two flanges that are held inside the pulley outer frame body and sandwich a part of the pulley outer frame body in the thickness direction, as well as a through hole and a screw hole that the pulley outer frame body has A split pulley including a spacer having a through hole communicating with the screw, a through hole and a screw hole of the pulley outer frame body, and a screw inserted into the through hole of the spacer.

  The groove provided on the outer peripheral surface of the pulley outer frame is a split pulley arranged at a position lower than the insertion position of the screw.

  A motor torque measurement device in which a divided pulley having the above-described configuration attached to a rotation shaft of a motor to be measured and a torque detection unit of the torque measurement device are connected by a wire.

  In the split pulley according to the present invention, the pulley divided bodies can be securely fixed to each other without looseness or misalignment by sandwiching a spacer having a flange portion between the plurality of pulley divided bodies. Even if it is short, there will be no inclination or distortion in the entire pulley during installation. Therefore, when a motor torque measuring device is configured using the motor, the rotation of the motor is not shaken and the torque can be measured accurately.

  FIG. 1 is a diagram showing a split pulley according to the present invention, wherein (a) is a top view and (b) is a cross-sectional view taken along line A-A ′ of (a). FIG. 2 is an exploded sectional view of the split pulley of the present invention. The split pulley of the present invention is broadly divided into a pulley outer frame body 21 that substantially functions as a pulley, a spacer 22 held inside the pulley outer frame body 21, a pulley outer frame body 21, and a spacer. And a screw 23 for integrally fastening to the screw 22.

  The pulley outer frame body 21 is a substantially cylindrical member having an appearance similar to that of a conventional split pulley, and two pulley divided bodies (hereinafter simply referred to as divided bodies) 21a and 21b that are equally divided in the radial direction are mutually connected. Are formed as one member, and a groove 24 having a substantially semicircular cross section is provided on the outer peripheral surface of the wire 8 (see FIG. 5). One of the two divided bodies 21a and 21b constituting the pulley outer frame body 21 is provided with a through hole 25a penetrating the inside in the radial direction, while the other divided body 21b is penetrated. At a position facing the hole 25a, a screw hole 25b having a thread groove formed on the inner peripheral surface is provided. Moreover, the substantially semicircular notch 21c engaged with the axis | shaft to be attached is provided in the lower end part of the division bodies 21a and 21b, and is in the state opened widely.

  The spacer 22 has a substantially columnar shape lower than the pulley outer frame body 21, and has a through hole communicating with a through hole 25 a and a screw hole 25 b provided in the two divided bodies 21 a and 21 b on the side surface. 26 is provided. The screw 23 is sequentially inserted into a through hole 25a provided in one divided body 21a and a through hole 26 provided in the spacer 22, and the tip thereof is a screw hole 25b provided in the other divided body 21b. Then, the two divided bodies 21a and 21b are fastened in a direction approaching each other, and the spacer 22 is sandwiched therebetween.

  Here, in a state where the lower end portion of the pulley outer frame body 21 is temporarily fastened to the attachment target shaft (a state where the pulley outer frame body 21 is not firmly fastened with screws), the pulley outer frame body 21 is disposed between the inner peripheral surface of the pulley outer frame body 21 and the outer peripheral surface of the spacer 22. The gap 27 is set so that a certain amount of gap 27 is generated, and the gap 27 acts as a fastening margin when fastening.

  In the present embodiment, of the three holes 25a, 25b, and 26 for inserting the screw 23, only the hole provided in the divided body 21b (screw hole 25b) is a screw hole. The through holes 25a provided in the divided body 21a and the through holes 26 provided in the spacer 22 may be screw holes.

  In addition, flanges 22 a and 22 b that protrude radially outward along the outer periphery of the spacer 22 are integrally formed at the upper end and the lower end of the spacer 22. Of the two flange portions 22a and 22b, the flange portion 22a on the upper end side contacts the upper end surface of the divided bodies 21a and 21b, while the flange portion 22b on the lower end side is a part of the inner wall of the divided bodies 21a and 21b. In this way, a part in the thickness direction of the divided bodies 21a and 21b is sandwiched between the two flange portions 22a and 22b.

  In this way, by sandwiching part of the divided bodies 21a and 21b in the thickness direction between the flange portions 22a and 22b of the spacer 22, the inclination and distortion of the pulley outer frame body 21 are corrected, and the pulley outer frame body 21 Since the inner wall of the notch 21c is in close contact with the mounting target shaft, the pulley outer frame body 21 is securely fixed to the mounting target shaft.

  In this embodiment, the lower end of the pulley outer frame body 21 is greatly opened in the radial direction assuming that the shaft diameter of the mounting target is large. The thickness of the lower end portion of the pulley outer frame body 21 may be increased radially inward according to the shaft diameter.

  Further, the flange portions 22a and 22b do not need to be formed uniformly along the outer periphery of the spacer 22, and are provided locally if the inclination and distortion of the pulley outer frame body 21 can be suitably suppressed. Also good.

  Further, the position of the groove 24 provided on the outer periphery of the split type pulley, that is, the part where the split type pulley and the wire are engaged, is provided as close to the motor as possible to reduce the center of rotation. In this embodiment, it is disposed at a position (lower position) lower than the insertion position of the screw 23.

  Further, the pulley outer frame body 21 is not necessarily limited to the structure that is divided into two, and may be configured to be further divided. However, a screw for fastening each divided body is necessary, and the number of parts increases. Since the handling property may be deteriorated, it is desirable to divide into two parts as in this embodiment.

  The split pulley according to the present invention is particularly suitable for a small motor such as a spindle motor having a short shaft, and can be securely fixed to the rotating shaft of the motor without causing the entire pulley to be inclined or distorted. . Therefore, when the split pulley of the present invention is applied to a motor torque measuring apparatus as shown in FIG. 5, a stable rotation can be obtained without the motor rotating at the time of torque measurement. Measurement can be performed.

  However, the split pulley according to the present invention is not applied only to the torque measuring device, but can also be used as a joint or the like for transmitting the rotational force of the motor to another drive mechanism.

It is a figure which shows the split-type pulley of this invention, (a) Top view, (b) A-A 'sectional drawing of (a) Exploded sectional view of the split pulley of the present invention It is a figure which shows the conventional split type pulley, (a) Top view, (b) A-A 'sectional drawing of (a). It is sectional drawing which shows the state which attached the conventional split type pulley to the rotating shaft of the motor, (a) The state which attached the split type pulley to the motor with a comparatively long rotating shaft, (b) The rotating shaft is relatively A state where a split pulley is attached to a short motor Sectional view schematically showing a torque measuring device for a motor using a split pulley

Explanation of symbols

1 Split type pulley 1a Pulley half 1b Pulley half 2 Notch 3 Groove 4a Through hole 4b Screw hole 5 Screw 6 Clearance (tightening allowance)
7 Motor 7a Rotating shaft (shaft)
8 Wire 9 Torque detection section 21 Pulley outer frame body 21a Pulley split body 21b Pulley split body 21c Notch 22 Spacer 22a Hook 22b Hook 23 Screw 24 Groove 25a Through hole 25b Screw hole 26 Through hole 27 Clearance (tightening allowance)
28 steps

Claims (3)

A split type pulley that fastens a plurality of divided bodies that are divided from each other in the radial direction with screws and fixes them to a shaft to be attached, at least,
A plurality of divided bodies that are divided from each other in the radial direction are combined as one member, and have a groove that engages the wire on the outer peripheral surface, and a through hole that passes through the inside in the radial direction and the through hole. A cylindrical pulley outer frame body having a screw hole disposed at a position opposite to
A through hole that is held inside the pulley outer frame body and has two flanges that sandwich a part of the pulley outer frame body in the thickness direction, and that communicates with a through hole and a screw hole of the pulley outer frame body A spacer having
A split pulley comprising: a through hole and a screw hole of the pulley outer frame body; and a screw inserted into a through hole of the spacer.   2. The split pulley according to claim 1, wherein the groove provided on the outer peripheral surface of the pulley outer frame is disposed at a position lower than the insertion position of the screw.   A torque measuring device for a motor in which a split type pulley attached to a rotating shaft of a motor to be measured and a torque detector of the torque measuring device are connected by a wire, wherein the split type pulley is the claim 1, or 2. A motor torque measuring device comprising the split pulley according to 2.

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