JPH01269723A - Device for joining shaft with rotor - Google Patents

Abstract

PURPOSE:To enable joining with a small number of parts by providing an eccentric ring-shaped inner race and an eccentric ring-shaped outer race having a tapered keyway, and moving the tapered key engaged with the keyway in the direction to the flange. CONSTITUTION:A joining device 10 comprises an eccentric ring-shaped inner, race 12, an eccentric ring-shaped outer race 13, a taper key 14 and a bolt 15. A tapered keyway 33 is disposed on the outer race 13. When the key 14 is pulled in the direction of a flange 23 by the bolt 15, the key 14 spreads outwards a thick portion of the outer race 13 in the circumferential direction by wedge action. Then, the outer race 13 eats into between the inner race 12 and a boss hole of a rotor 19. Accordingly, the boss hole of the rotor 19 is tightened by the outer peripheral surface of the outer race 13, and on the other hand, the inner race 12 is pressed by the inner peripheral surface of the outer race 13, so that the inner race 12 is reduced in diameter to tighten a shaft 18. Thus, the respective members tighten the shaft and the rotor by frictional force.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fastening device for a shaft and a rotating body (such as a gear, a sprocket, or a joint).

Conventional technology and its! 1K Problem Conventionally, as shown in FIGS. 7 and 8, devices for fastening a shaft and a rotating body include an inner race 52 and an outer race 53 having tapered surfaces in both directions, and two tapered rings 54 and 54. There is also one consisting of a plurality of bolts 55. In this device, by tightening the bolt 55 in the axial direction, each tapered ring 54, 54 approaches each other, and each race 52, 53 contracts and expands in diameter, respectively, and the friction force causes the rotating body to be attached to the shaft 18'. 19' is to be fastened.

However, such a fastening device has a large number of parts, resulting in high costs. Another problem is that processing the tapered surface and finishing the surface require many man-hours. In addition, as shown in the figure, there are many bolts, and the tightening torque of each bolt 55 must be managed uniformly, which has the disadvantage that it takes time to install, and it is difficult to insert tools and the working posture is cramped. .

There is also a two-piece type fastening device that comes into contact with the tapered surface in the axial direction, but in this case, there is a problem that additional jig parts are required for mounting, and a tapped hole must be provided in the shaft or rotating body. There is.

Other fastening devices are disclosed in Japanese Utility Model Application Publication No. 60-52424 and can be attached with a single nut. However, this type of fastening device is limited to a small size due to its structure.

An object of the present invention is to solve the above-mentioned conventional problems and provide a fastening device that utilizes the action of an eccentric surface rather than the wedge action of a tapered surface as in the past.

Means for Solving the Problems This invention provides an eccentric ring-shaped inner race having a flange at one end and having a slit formed in the axial direction, and an inner race having a tapered keyway and having a slit formed in the axial direction. It has an eccentric ring-shaped outer race into which the inner race fits, a tapered key that fits into the keyway, and a bolt for moving the key toward the flange, and the key is connected to the port, the The above-mentioned problem has been solved by a fastening device for a shaft and a rotary body, in which the outer race is pushed out in the circumferential direction by a wedge action when the outer race moves in the flange direction.

When the key is pulled toward the flange by the action bolt, the key pushes and expands the thick part of the outer race in the circumferential direction due to its wedge action. Then, the outer race bites between the inner race and the boss hole of the rotating body. Therefore, the outer circumferential surface of the outer race tightens the boss hole, while the inner circumferential surface of the outer race presses the inner race, causing the inner race to contract. diameter and tighten the shaft. In this way, each member fastens the shaft and the rotating body by frictional force.

Embodiments will be described in detail below with reference to the drawings. FIG. 1 is an exploded perspective view showing an embodiment of the fastening device of the present invention.

Fastening device of the present invention! The tIO is composed of an inner race 12, an outer race 13, a tapered key 14, and a bolt 15.

The eccentric ring-shaped inner race 12 is a cylinder having an inner circumferential surface 21 for fitting onto the shaft 18 (see FIGS. 5 and 6) and an eccentric surface 22 on the outer circumference that is eccentric with respect to the inner circumferential surface 21. It consists of a portion 20 and a ring-shaped flange 23 whose diameter increases at one end in the axial direction and is concentric with the inner circumferential surface 21. Therefore, the cylindrical portion 20 has different wall thicknesses in the circumferential direction.

A bolt hole 24 passing through the flange 23 is provided at a position corresponding to the minimum thickness portion of the cylindrical portion 20, and a counterbore 24a (for fitting the head 15a of the bolt 15) is provided on the end surface side of the flange 23. Figure 2.

(see FIG. 5) is formed.

The inner race 12 is further provided with slit groups 25 at equal positions from the port holes 24, that is, at positions with equal wall thickness. do.

As shown in FIG. 3, the slit group 25 includes a first slit 25a extending from one end surface to the other end surface, and a first slit 25a extending from the other end surface toward one end surface. It consists of second slits 25b, 25b sandwiched therebetween. None of the slits are penetrating and have terminal ends slightly spaced apart from the end faces. A U-shaped portion 26 is thus formed. These slit groups serve to absorb elastic deformation when the inner race 12 contracts in diameter.

The outer race 13 , also in the shape of an eccentric ring, has an outer diameter slightly larger than or equal to the flange 23 , an inner diameter approximately equal to the outer diameter of the inner race 12 , and an outer circumferential surface 31 for fitting into the rotating body 19 . and inner lace 1
It has an inner circumferential eccentric surface 32 having the same eccentricity as the outer circumferential eccentric surface 22 of No. 2, and its width is approximately the same as that of the cylindrical portion 20. As a result, the rotating body 19 (see FIGS. 5 and 6) is arranged concentrically with the shaft 18. The outer race 13 also has different wall thicknesses in the circumferential direction. A tapered keyway 33 is provided in the thickest portion, expanding from the end surface facing the flange 23 toward the other end.

The outer lace 13 is further provided with a group of slits 35 similar to the inner lace 12.

As shown in FIG.
The second slits 35b, 35b of the book have a U-shaped portion 36, and the slit group 25 of the inner lace 12
It has the same function as . In this embodiment, the slit groups 35 of the outer lace 13 are formed at positions evenly spaced 120° from the maximum thickness portion to the left and right.

14 is a tapered key, the outer periphery 41 and the inner periphery 42 have approximately the same curvature as the outer race 13, the side surface 43 has the same taper angle as the key groove 33, and its thickness is equal to the maximum thickness of the outer race 13. It is slightly thinner. The key 14 has a bolt 15 passing through the bolt hole 24 of the flange 23.
A threaded hole 44 is provided for threading. Note that the screw hole 44 is preferably a blind hole in order to confirm the direction in which the key 14 is assembled. Further, the length of the key 14 is shorter than the width of the outer race 13 by the amount of its movement It (see explanation of operation described below), and its width is set to such a size that the key 14 touches the flange 23 or retracts slightly when fastening. put(
(See Figure 4).

Numeral 15 is a hexagon socket head bolt for tightening the key 14 and the flange 23, and the head 15a is fitted into a counterbore 24a for safety during rotation. The length is such that it does not interfere with the bottom of the bolt hole of the key 14 (in the case of a blind hole). Further, a disc spring washer 16 may be used to facilitate tightening.

In FIG. 5, when the fastening device 10 of this embodiment is installed between the shaft 18 and the rotating body 19 and the bolt 15 is tightened,
The key 14 moves toward the flange 23, and the thick portion of the outer race 13 is expanded in the circumferential direction due to the wedge action of the tapered surface (side surface). Then, as shown by the arrow in FIG. 6, the outer race 13 bites between the outer peripheral eccentric surface 22 of the inner race 12 and the boss hole 19a, and although the six races are slightly deformed as they are tightened, each slit Group 25.35 resorbs this deformed bone.

Thus, the outer peripheral surface 31 of the outer race 13 is aligned with the boss hole 1.
9a, the inner peripheral eccentric surface 32 presses the outer peripheral eccentric surface 22 of the inner race 12, respectively. Therefore, the inner race 12 elastically contracts in diameter and tightens the shaft 18. In this manner, the relatively thick portion of the outer race 13 is forcibly pushed into a relatively narrow space, thereby generating pressing force inward and outward. Although this uses a curved surface, the principle is similar to wedge action.

The shaft 18 and the rotating body 19 are firmly connected by the strong clamping force and frictional force generated by such an action.

To release the fastening state of the fastening device 10, the bolt 15 is loosened. The outer race 13 attempts to return to its original shape by the elastic action of the slit group 35, but if the fastened state is not released, the head 15a protruding from the counterbore 24a may be lightly tapped with a hammer or the like. Then, the key 14 separates from the keyway 33 and the outer race 13
Due to the elastic repulsive force of the slit group 35, the outer lace 13 is restored to its original shape and the fastened state is released.

In this way, the fastening device of the present invention consists of four members,
It does not require processing or additional parts for attachment to the shaft or rotating body, and can be attached and detached with a single bolt.

Effects of the Invention Since the present invention has the above-described configuration, the number of parts is small, and it can be fastened by simply tightening one bolt.

Because of the double wedge action of the key and the eccentric surface, the shaft and the rotating body can be firmly connected by simply tightening the bolt with a light force, and can be easily released. Therefore, the bolt may be thin, and the fastening device can be made compact and thin even when used for a large diameter shaft.

In addition, the contact surfaces of the outer race and inner race that generate the fastening force are not tapered surfaces but eccentric cylindrical surfaces, making processing easy, and the relative movement direction is in the processing direction of each member (for example, at the turning port). direction), making tightening smoother.

Moreover, since the outer race and the inner race do not move in the axial direction, accurate positioning is possible.

[Brief explanation of the drawing]

1 to 6 represent embodiments of the fastening device of the present invention,
Fig. 1 is an exploded perspective view, Fig. 2 is a front view of the outer lace as seen approximately centered on the slit, Fig. 3 is a front view of the inner lace as seen approximately centered on the slit, and Fig. 4 is a front view of the outer lace as seen approximately centered on the slit. A plan view showing the attachment relationship between the outer race and the key, Fig. 5 is an explanatory view showing the state of engagement between the shaft and the rotating body, Fig. 6 is a front view with a part of the rotating body removed from Fig. 5, and Fig. 7. and FIG. 8 are a perspective view and a sectional view of essential parts of a conventional fastening device. 10... Fastening device 12... Inner race 13... Outer race 14... Key 15... Bolt 18... Shaft 19... Rotating body 23... Flange 25.35... Slit 33...Keyway Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 5 to 8

Claims (1)

[Claims] An eccentric ring-shaped inner race that has a flange at one end and has a slit formed in the axial direction, and the inner race that has a tapered keyway and has a slit formed in the axial direction are fitted together. a tapered key that fits into the keyway; and a bolt for moving the key toward the flange; and the key is moved toward the flange by the bolt. A fastening device for a shaft and a rotating body, characterized in that the outer race is expanded in the circumferential direction by a wedge action.