JP2012013196A - Driving force transmission structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent backlash without increasing the accuracy of tolerance between a shaft diameter D1 of a tip portion 1a of a shaft 1 and an inner diameter D2 of a bore 3a of a pulley 3.SOLUTION: In a driving force transmission structure a tip portion 1a is provided and a pulley 3 is secured by a screw 4 to a shaft 1 with a threaded hole 1x formed at the tip portion 1a. The pulley 3 is a molded product formed by a resin material, and is provided with a slit 3x on a part or the whole outer periphery, to prevent backlash by opening and deforming the slit 3x in axial direction by screw tightening torque.

Description

  The present invention relates to a driving force transmission structure in an automatic transaction apparatus such as an automatic teller machine.

  Conventionally, in a driving force transmission structure in which a rotational driving force of shafts is transmitted to other driving systems by pulleys, fastening by an interference fit is generally used for coupling the shafts and pulleys. In order to prevent backlash between the shafts and the pulleys, an interference fit (tight fit) is realized by putting a tolerance in the shaft diameter of the shafts and the hole diameter of the pulleys (see, for example, Patent Document 1).

  FIG. 3 is a diagram showing a configuration of a conventional driving force transmission structure, FIG. 3 (a) is an external perspective view, and FIG. 3 (b) is a side sectional view. As shown in the figure, the conventional driving force transmission structure has a pulley 103 having an inner hole 103a having a hole diameter D2 and a tip portion 101a having a shaft diameter D1 and a screw hole 101x in the tip portion 101a. The pulley 103 is fixed to the shaft 101 with a screw 104.

  If the pulley hole diameter D2> the shaft shaft diameter D1, the pulley 103 and the shaft 101 are rattled in the direction perpendicular to the axis. To prevent this, the pulley hole diameter D2 <the shaft shaft diameter D1, that is, the pulley 103 and the shaft 101 Was to be an interference fit.

Japanese Patent Laid-Open No. 11-37221

  However, in the conventional driving force transmission structure, if the tolerance accuracy is low, the shaft diameter D1 of the shaft 101 having the maximum tolerance and the hole diameter D2 of the pulley 103 having the smallest tolerance are overtightened, and the assemblability is poor. However, there was a problem that great power was required.

  Further, when the pulley 103 is a molded product such as a resin material, it is difficult to increase the tolerance accuracy, and it is difficult to eliminate the play.

  The present invention employs the following configuration in order to solve the above-described problems. That is, a driving force transmission structure in which a pulley is fixed to a shaft having a distal end portion and a screw hole formed in the distal end portion by a screw, and the pulley has a slit in a part or all of its outer periphery, The slit was opened in the axial direction by torque and deformed to suppress backlash.

  According to the driving force transmission structure of the present invention, a driving force transmission structure in which a pulley is fixed to a shaft having a distal end portion and a screw hole at the distal end portion by a screw, and the pulley is partially disposed on an outer periphery. Alternatively, since all the slits are provided and the slits are opened and deformed in the axial direction by screw tightening torque to suppress the play, the occurrence of play can be reduced without increasing the tolerance accuracy.

1 is a configuration diagram of a driving force transmission structure of Embodiment 1. FIG. It is operation | movement explanatory drawing (side sectional drawing) of the driving force transmission structure of Example 1. FIG. It is a block diagram of the conventional driving force transmission structure.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element common to drawing.

(Constitution)
FIG. 1 is a configuration diagram of the driving force transmission structure according to the first embodiment, FIG. 1A is an external perspective view, FIG. 1B is a side sectional view, and FIG. A modification is shown.

  The driving force transmission structure of Embodiment 1 has an inner hole 3a with a hole diameter D2, a pulley 3 that is a molded product made of a resin material, a tip portion 1a with a shaft diameter D1, and a screw hole 1x provided in the tip portion 1a. The pulley 1 is fixed to the shaft 1 with a screw 4.

  In the driving force transmission structure according to the first embodiment, the pulley 3 is a pulley with a slit, and the slit 3x is provided on the outer periphery of the pulley 3 over the entire circumference in the direction perpendicular to the axis. In addition, as shown in FIG.1 (c), the said slit 3x may be provided only in a part of outer peripheral direction, and may be provided only in a part of axial direction.

(Operation)
With the above configuration, the driving force transmission structure of the first embodiment operates as follows. This operation will be described in detail below with reference to FIG.

  The arrow Fs in the figure is the screw tightening torque generated when the screw 4 is tightened, and the arrow Fp is the pressing force generated by the screw tightening torque Fs.

  When the screw tightening torque Fs is applied, the pulley 3 is formed from a resin material, and the slit 3x is provided on the tooth surface thereof. The pulley 3 with slits is deformed. This deformation can suppress backlash in the direction perpendicular to the axis.

  Therefore, in the driving force transmission structure of the first embodiment, the pulley hole diameter D2 <the shaft shaft diameter D1, that is, the tolerance accuracy of the pulley hole diameter D2 and the shaft shaft diameter D1 so that the relationship between the pulley 3 and the shaft 1 is maintained. There is no need to increase.

  In the above description of the embodiment, the pulley 3 has been described as a molded product made of a resin material. However, the pulley 3 may not be a resin material as long as it is a material that deforms a little by the fastening force Fx.

  Further, in the above description of the embodiment, the driving force transmission structure including the shaft and the pulley is described as an example of the fastening part. Can be applied as well. In this case, a slit may be provided on the outer periphery of the recess over a part or the entire length in the direction perpendicular to the axis.

(Effect of Example 1)
As described above, according to the driving force transmission structure of the first embodiment, the driving force transmission structure is configured to fix a pulley with a screw to a shaft having a tip portion and having a screw hole at the tip portion.・ Slits are partially or wholly provided on the outer periphery, and the slits are opened and deformed in the axial direction by screw tightening torque so as to suppress backlash. Can do.

  As described above, the present invention can be widely used in an automatic transaction apparatus such as an automatic teller machine having a driving force transmission structure for transmitting a driving force of a motor or the like with a belt or the like.

1 Shaft 1a Tip 1x Screw hole 3 Pulley 3a Inner hole 3x Slit 4 Screw D1 Shaft shaft diameter D2 Pulley inner diameter

Claims (2)

A driving force transmission structure for fixing a pulley with a screw to a shaft having a tip portion and having a screw hole in the tip portion,
The pulley has a slit on a part or all of its outer periphery, and is configured to open and deform the slit in the axial direction by screw tightening torque to suppress backlash.   The driving force transmission structure according to claim 1, wherein the pulley is a molded product made of a resin material.

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