JPH0140354Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a combination spring used in a torque transmission section of a flexible shaft joint that transmits a relatively large torque.

(Prior art) Some new flexible shaft joints (for example, Japanese Patent Publication No. 55 −6776,
Special Publication No. 55-6777, Special Publication No. 55-6778, Jitsugan No. 1983
−133151) has been developed.

These flexible shaft joints consist of a pair of hubs that are spaced apart and aligned so that their axes coincide, and a pair that extends parallel to the axis between the hubs and is arranged circumferentially around the hubs. It is composed of a plurality of sets of spring seats, and a coil spring interposed between the opposing spring seats so that the spring shaft is oriented in the tangential direction of the hub circumference.

In the flexible shaft joint configured as described above, when a rotational force acts and the first hub and the second hub rotate relative to each other, the first hub and the second hub rotate in a circle regardless of the direction of rotation. The coil spring, which is relatively displaced in the circumferential direction and supported at both ends by the two spring seats, is compressed. The rotational force from the drive shaft is transmitted to the first hub, the spring seat 25, the coil spring 28, and the spring seat 2.
5. The signal is transmitted sequentially to the second hub and the driven shaft.

For example, with a flexible shaft joint configured as described above,
When transmitting large torques such as 5000 Kg-m, the coil spring becomes significantly large. As a result, the flexible shaft joints are of considerable size. Therefore, it is conceivable to use a disc spring instead of a coil spring. However, if a flexible shaft joint is to have a large damping effect, a large number of disc springs, for example 40, must be stacked and used.

When using a large number of disc springs like this, in order to adjust the misalignment of the axes and obtain a large elastic action, it is necessary to horizontally buckle the stacked disc springs (laminated disc springs), that is, to curve the spring shaft. Requires a disc spring guide that can tolerate deformation. Further, this disc spring guide must be able to guide the disc spring even when the laminated disc spring is greatly bent.

In order to solve such problems, Japanese Patent Application Laid-Open No.
A combination spring disclosed in Japanese Patent No. 184331 has been proposed. The combination spring of this invention is supported between opposing spring seats and is comprised of a coil spring and a laminated disc spring combined in parallel. One of the coil spring and the disc spring is loosely engaged with the guide, and the other spring is loosely engaged with the loosely engaged spring.

In the combination spring configured in this way, the disc spring is loosely engaged with the coil spring, so the coil spring serves as a guide for the disc spring. Therefore, when the flexible shaft joint transmits torque while absorbing eccentricity, even if the opposing spring seats shift from each other and the axis of the coil spring curves, the coil spring will guide the disc spring and maintain the laminated structure. Prevents lateral buckling of the spring.

(Problems to be solved by the invention) However, it has been found that the above combination spring has the following problems. That is, if the eccentricity to be absorbed is large, the coil spring will curve greatly, and the gap between the coil wires on one side (between the wires) will be wide open at the center of the spring, and narrow on the other side. Then, a disc spring fits between the open lines. Also, when a large impact force perpendicular to the spring axis acts on the disc spring, the disc spring pushes open the wires of the coiled spring and enters between the wires. If the disc spring gets stuck between the wires, the coil spring or disc spring will be damaged by the load during torque transmission.

(Means for Solving the Problems) A shaft joint in which the combination spring of this invention is incorporated consists of a pair of hubs spaced apart in the axial direction and assembled so that their axes coincide, and a plurality of pairs of spring seats extending in parallel and spaced apart in the circumferential direction of the hub;
It is comprised of a combination spring interposed between opposing spring seats such that the spring shaft is oriented in the tangential direction of the hub circumference.

The above-mentioned combination spring consists of a coil spring and a laminated disc spring that is loosely engaged with the outer side of the coil spring.
The end portion of the combination spring is loosely engaged with an annular groove provided in the spring seat. Further, the ratio of the size of the gap between the wires at the center of the coil spring to the thickness of the disc spring is 0.1 or less. The spring wires may be in close contact.

The length of the central portion of the coil spring is at least the length of the portion of the laminated disc spring where the outer peripheral surface is not guided by the annular groove of the spring seat. The length of this central portion varies depending on the dimensions of the combination spring and the load to be transmitted, but is suitably 1/4 to 1/3 of the length of the spring assembled in the shaft joint, for example. If the length of the central portion becomes too long, the maximum amount of deflection of the spring will decrease, and the eccentricity absorption and shock mitigation functions will deteriorate. On the other hand, if it is too short, it may be necessary to absorb large eccentricity, or if the
When a large impact force is applied to a disc spring, the disc spring gets stuck between the wires of the coil spring, damaging the spring.

(Function) Even if the coil spring is greatly curved to absorb eccentricity, or even if a large impact force perpendicular to the spring axis is applied to the disc spring, the spring wires will not bend at the center of the combination spring. Since the wires are in close contact or the gap between the wires is small, the disc spring will not fit between the wires.

(Example) An example of this invention will be described below. 1st
As shown in FIG. 2 and FIG. 2, the first hub 5 has a flange 7 integrally provided at the tip of a cylindrical portion 6.
The flange 7 is provided with four elongated holes 8 at intervals of 90° along the circumference. The elongated hole 8 has an arc-shaped side surface 9.

The second hub 11 is a flange 1 at the tip of the cylindrical portion 12.
3 are provided as one unit. This flange 13 is provided with a notch 14 having an arc-shaped side surface 15 at a position corresponding to the elongated hole 8 of the first hub flange 7.

The connecting piece 18 includes a flange 20 protruding in the outer diameter direction at one end of the cylindrical portion 19 and a flange 21 protruding in the inner diameter direction at the other end. Flange 21
A notch 22 having an arc-shaped side surface 23 is provided at a position corresponding to the elongated hole 8 of the first hub flange 7 . The first hub flange 7 is the cylindrical portion 19 of the connecting piece 18 when each member is assembled as a shaft joint.
stored inside.

FIG. 3 shows an example of a spring seat. Two annular grooves 46 are provided on a plane 45 opposite to the semi-cylindrical surface 44 along the longitudinal center line l. Moreover, the inner side of the annular groove 46 has a cylindrical guide 4.
It has become 7.

As shown in FIG. 4, a coil spring 49 and a laminated disc spring 51 are set between two opposing spring seats 43 to form a transmission member 41. The center portion of the coil spring 49 has a slightly larger coil diameter, and the spring wire is in close contact with it. The length of the close contact portion is approximately 1/3 of the length of the set coil spring 49. The inner peripheral surface of both ends of the coil spring 49 is connected to the guide 4.
7, the outer peripheral surface is loosely fitted to the inner peripheral surface of the laminated disc spring 51. The outer circumferential surfaces of both ends of the laminated disc spring 51 are loosely fitted into the outer circumferential wall of the annular groove 46, and the inner circumferential surface of the central portion is loosely fitted with the outer circumferential surface of the central portion of the coil spring 49.

The holding plates 31 and 32 have an annular shape, and are attached to the flange 13 of the second hub 11 and the connecting piece 1, respectively.
It is attached to the flange 21 of 8.

The flexible shaft joint is assembled using the above-mentioned members as follows.

The first hub 5 and the second hub 11 are arranged so that their respective flanges 7 and 13 face each other, and the connecting piece 18 is attached to the second hub flange 13 with bolts so as to accommodate the first hub flange 7.
It is fixed by a nut 34. At this time,
The elongated hole 8 of the first hub flange 7, the notch 14 of the second hub flange 13, and the notch 22 of the flange 21 of the connecting piece 18 are arranged so as to open along the axial direction of the shaft joint, and form a housing portion 39. are doing.

Torque transmission member 41 configured as described above
The coil spring 49 and the disc spring 51 are preloaded and inserted into the housing portion 39 so that the spring shafts are along the tangential direction of each of the flanges.

In the spring seat 43, both ends of the cylindrical surface 44 are connected to the cylindrical surface 1 of the notch 14 of the second hub flange 13.
5 and the cylindrical surface 23 of the notch 22 of the connecting piece flange 21, and the center portion of the cylindrical surface 44 is supported by the arcuate surface 9 of the long hole 8 of the first hub flange 7. Also, attach the holding plate 31 to the bolt 36.
The presser plate 32 is fixed to the second hub flange 13 and the flange 21 of the connecting piece 18 by bolts 37, and the spring seat 43 is fixed to the accommodating part 3.
It prevents you from getting out of 9.

When the flexible shaft joint configured as described above transmits torque, both the coil spring 49 and the laminated disc spring 51 are compressed. At this time, since the laminated disk spring 51 is guided by the coil spring 49, lateral buckling does not occur even if the coil spring 49 is deformed such that the spring axis thereof curves. Furthermore, since the spring wires at the center of the coil spring 49 are in close contact with each other, the disk spring 51 does not get stuck between the wires. Furthermore, since both springs 49 and 51 bear the load, a large torque can be transmitted.

It is preferable for the coil spring 49 to have a rectangular wire surface as shown in FIG. 4 in order to guide the laminated disc spring 51.

(Effect of the invention) Even if the amount of eccentricity absorbed by the shaft joint is large, or even if a large lateral impact force is applied to the disc spring,
The disc spring does not get stuck between the coil springs,
No damage to coil springs or disc springs. Furthermore, this invention is practical because it can be implemented by simply bringing the spring wires in the center of the coil spring into close contact, and no extra parts such as a sleeve are required.

[Brief explanation of the drawing]

1 and 2 are a sectional view and a partially cutaway front view, respectively, showing an example of a flexible shaft joint in which the combination spring of this invention is used. FIG. 3 is a perspective view showing an example of a spring seat constituting a torque transmission member including a combination spring of this invention. FIG. 4 is a sectional view showing an example of a torque transmitting member including a combination spring of this invention. 1, 2... Shaft, 5, 11... Hub, 41... Torque transmission member, 43... Spring seat, 46... Annular groove, 47... Guide, 49... Coil spring, 51
...Laminated disc spring.

Claims (1)

[Scope of utility model registration request] A pair of hubs that are spaced apart in the axial direction and combined so that their axes coincide, and a plurality of hubs that extend parallel to the axis between both hubs and are spaced apart in the circumferential direction of the hub. A shaft joint configured with a pair of spring seats and a combination spring interposed between the opposing spring seats so that the spring axis is oriented in a tangential direction of the hub circumference, the combination spring comprising: Consisting of a coil spring and a laminated disc spring that loosely engages with the outside of the coil spring, the end of the combination spring loosely engages an annular groove provided in the spring seat, and A combination spring for a shaft coupling, characterized in that the ratio of the size of gaps between wires is 0.1 or less.