JPH0866839A - Floating coupling - Google Patents

Abstract

PURPOSE: To provide a floating coupling which is held at high rigidity in the directions of rotation and its axis and has degrees of freedom in other directions. CONSTITUTION: This floating coupling has a structure comprising a pair of seat plats 1, 2, four connecting plates 3, 4, 5, 6 and an intermediate plate 7, one of the seat plates being coupled to the intermediate plate 7 with two of the connecting plates arranged in parallel between them, the other seat plate being coupled to the intermediate plate 7 with the other two connecting plates arranged in parallel between them, with the seat plates and the connecting plates being coupled into turning pairs, and the connecting plates and the intermediate plate 7 coupled into spherical pairs. Therefore, the pair of seat plates 1, 2 is prevented from rotating and moving in the direction of its axis and is made to float in other directions.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This floating joint is intended mainly for connecting a ball screw nut and a pedestal, and can also be applied to a joint between general rotating shafts.

[0002]

2. Description of the Related Art Generally, when a ball screw is used, a male screw is arranged on the fixed side and a nut is arranged on the moving side in many cases. In this case, a lot of centering work is required, such as parallel alignment of the male screw and the moving part, and center height and inclination of the nut and the male screw. A block-shaped member or an L-shaped stay is often used as the conventional nut-moving unit coupling means. Since these connecting means do not include an adjusting element for centering, a centering operation using a shim or scraper is required. This requires skill and a lot of effort. If the centering is incomplete, unbalanced loads and twisting will occur. In addition, in the conventional cantilever type nut coupler, when a large load is applied,
The nut may tilt and cause unbalanced load or twisting. Such an eccentric load or twisting not only impairs the accuracy of the ball screw but also greatly affects the life.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a floating joint which maintains high rigidity in the rotational direction and the axial direction and has a degree of freedom in the other directions. If the nut is attached by this floating joint, the nut and the male screw are automatically aligned, and the centering work for assembling the ball screw is not necessary.

[0004]

SUMMARY OF THE INVENTION The floating joint of the present invention comprises:
It consists of a pair of seat plates, four connecting plates and an intermediate plate. One seat plate connects two connecting plates to the intermediate plate in parallel, and the other seat plate connects the other two connecting plates. The structure is such that the intermediate plate is connected in parallel, the seat plate and the connecting plate are connected as a rotating pair, and the connecting plate and the intermediate plate are connected as a spherical pair.

[0005]

In the above structure, by mounting the nut on one of the seat plates and fixing the other seat plate, rotation and axial movement of the nut are prohibited at the nut and the fixed portion, and the nut is prevented from floating in the other direction. Become.

[0006]

1 is a front sectional view of an embodiment of the present invention, and FIG. 2 is a bottom view of FIG. The part represented by the two-dot chain line in the figure is the ball screw nut 11 and the male screw 12.
And the nut mounting seat 13. Details will be described below with reference to FIGS. 1 and 2.

The seat plate 1 is a rectangular plate member having a hole in the center and has the same shape as the seat plate 2. The intermediate plate 7 is a square plate member having a hole in the center. The four connecting plates 3, 4, 5, and 6 are all plate-shaped members having the same shape, and spherical bearings are formed at three corners. Spherical bearing is spherical body 8
And a resin liner 9, and the outer ring portion is integrally formed with the plate member. The spherical body 8 has a through hole at the center and has a structure in which it is connected to another member by a bolt 10.

A connecting plate 3 and a connecting plate 4 are connected to opposite sides of the seat plate 1 by spherical bearings at two positions.
In this case, the seat plate and the connecting plate form a hinge pair having a degree of freedom of 1 like a hinge about a line passing through the centers of the spherical bearings at two positions.

The other spherical bearings of the connecting plate 3 and the connecting plate 4 are respectively connected to the central portions of the opposite sides of the intermediate plate 7. In this case, the connecting plate and the intermediate plate are spherical pairs with three degrees of freedom.

On the other two opposite sides of the intermediate plate 7, a connecting plate 5 and a connecting plate 6 are spherically coupled like the connecting plate. The other two spherical bearings of the connecting plate 5 and the connecting plate 6 are respectively connected to the opposite side portions of the seat plate 2 similarly to the connecting plate.

The seat plate 1, the intermediate plate 7 and the connecting plates 3 and 4 form a parallel link. The seat plate 2, the intermediate plate 7, and the connecting plates 5 and 6 also form parallel links. The two sets of parallel links are offset by 90 degrees at the joint of the intermediate plate 7.

In the floating joint having the above construction, the seat plate 2 is arranged in a state of being bent at 90 degrees with respect to the seat plate 1, a nut 11 is attached to the seat plate 1, and the seat plate 2 is a nut mounting seat 1 of the moving part.
The operation will be described with reference to an example of use in the state of being attached to No. 3.

In the assembled state of FIG. 1, the nut 11
Has no degree of freedom in the rotational direction and the axial direction with respect to the nut mounting seat 13. The shift in the height direction Y shown in FIG. 4 can be absorbed by the change in the support angle Q between the nut side seat plate and the connecting plate. The lateral deviation X shown in FIG. 3 can be absorbed by a change in the support angle P of the seat plate on the nut mounting seat side and the connecting plate. The inclination S of the nut mounting seat in FIG. 4 can be absorbed by the change in the support angle R between the connecting plate and the intermediate plate on the mounting seat side. The inclination T of the seat plate on the mounting seat side in FIG. 5 can be absorbed by a change in the support angle V between the connecting plate and the intermediate plate on the nut side.

FIG. 6 shows an example of use in which a pair of seat plates are arranged so as to face each other, and is applied to a joint of a rotary shaft. In this embodiment, a boss 13 and a boss 14 are added to the pair of seat plates, respectively, and are used for joining the rotary shaft 15 and the rotary shaft 16. In the figure, biaxial misalignment Z and bending S can be absorbed.

[0015]

As explained above, if the nut of the ball screw is assembled by using the floating joint of the present invention, the centering work is unnecessary because the centering is automatically performed. Further, since the load acting on the nut is always in the vicinity of the center of the nut, the load is evenly applied to the threaded portion, and good accuracy and life can be obtained. In the above-mentioned embodiment, two spherical bearings are used for connecting the seat plate and the connecting plate. However, such a spherical bearing is a highly accurate kinematic pair with no rattling, as compared with the regular kinematic pair of pins and bearings. Can be easily realized. Further, the same processing as the spherical bearing at the connecting portion of the intermediate plate and the connecting plate may be performed, which is advantageous in manufacturing. In addition, when used as a joint for a rotary shaft, one joint can absorb both misalignment and bending, and has the advantage that it has higher rigidity and can withstand higher loads than joints that utilize the deflection of materials.

[0016]

[Brief description of drawings]

FIG. 1 is a front sectional view of an embodiment of the present invention.

FIG. 2 is a bottom view of the embodiment of the present invention.

FIG. 3 is a left side view for explaining the operation of the present invention.

FIG. 4 is a front sectional view for explaining the operation of the present invention.

FIG. 5 is a bottom view for explaining the operation of the present invention.

FIG. 6 is a front view of another usage example of the present invention.

[Explanation of symbols]

 1 seat plate 2 seat plate 3 connecting plate 4 connecting plate 5 connecting plate 6 connecting plate 7 intermediate plate 8 spherical body 9 liner 10 bolt 11 nut 12 male screw 13 nut mounting seat 14 boss 15 rotating shaft 16 rotating shaft

Claims (2)

[Claims] 1. A pair of seat plates, four connecting plates and an intermediate plate. One seat plate is connected to the intermediate plate via two connecting plates in parallel, and the other seat plate is connected to the other plate. The connecting plates are connected in parallel to the intermediate plate, and the seat plate and the connecting plate are connected as a rotating pair,
A floating joint characterized in that the connecting plate and the intermediate plate are connected by a spherical pair. 2. The connecting plate is provided with three spherical bearings, the seat plate and the connecting plate are connected by two spherical bearings, and the intermediate plate and the connecting plate are connected by one spherical bearing. The floating joint according to claim 1.