JPS5856448Y2 - lead screw nut - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a feed screw nut that absorbs misalignment between the nut and the male screw without impairing rigidity in the feed direction.

With a feed screw that moves an object by the rotation of the male thread through a nut that is screwed into the male thread, if there is misalignment between the nut and the male thread, the contact part may wear unevenly and cause abnormal wear. Stick-slip occurs due to abnormal surface pressure, which is problematic as a precision feeding mechanism.

In order to solve these problems, the axle box that houses the nut has traditionally been divided into two parts, the flange member and the axle box, and the flange member is attached to the object to be fed, and the axle box member is attached to the flange member via an elastic body. It has been installed.

However, structurally, the rigidity in the feeding direction is inevitably low, and it is not suitable as a precision feeding mechanism.

This idea creates an uneven curved surface with the same radius of curvature on the contact surface between the flange member and the axle box member, and makes sliding contact with the side curved surface to perform an alignment effect and absorb misalignment between the nut and the male thread. This solves the problems of the conventional products mentioned above.

Next, an embodiment of this invention will be described with reference to the drawings.A male screw 4 is inserted into a cylindrical axle box member 3 that houses a pair of nuts 1 and 2 inside, and the male screw 4 is inserted into the nuts 1 and 2. They are screwed together.

In addition, a lid 5 is fixed to the open end of the axle box member 3 by screws 9, and a flange 6 of the lid comes into contact with the end surface of the nut 2, fixing the nuts 1 and 2 in a non-rotatable manner within the axle box member 3. has been done.

On the other hand, the flange member 7 is fixed to the object to be sent 8 by a screw 10, and at the same time is in contact with the end surface of the axle box member 3.

A convex curved surface 11 is formed on the axle box member's contact surface with the flange member 7, and a concave curved surface 12 having the same radius of curvature R as the convex curved surface is formed on the contact surface of the flange member that contacts the convex curved surface. Therefore, the side curved surfaces can slide against each other.

Further, the axle box member 3 has three protrusions 13 with through holes 15 equally spaced on the outer circumference, and the flange member 7
A through hole 14 is bored in the hole corresponding to the protrusion 13 .

From the through hole 14 of the flange member to the through hole 15 of the axle box member 3
The head of the pin 16 inserted toward the flange member 7
It is locked to.

Also, the bottom surface 1 of the hole drilled in the axial direction in the projection 13 of the axle box member
7 and a spring receiver 18 inserted into the tip of the pin 16. When the nut 20 screwed into the tip of the pin 16 is tightened, the spring 19 is compressed and the axle box The member 3 is pressed against the flange member 7 to fix both members.

Therefore, the preload of the compressive load bone of the spring 19 is always applied to both members.

Note that the step 10 for fixing the flange member 7 to the object to be sent is
As shown in an enlarged view in FIG. 3, an elastic body 30 such as rubber is used.
It may also be attached via.

Furthermore, it goes without saying that the flange member 7 can be provided with a convex curved surface and the axle box member 3 can be provided with a concave curved surface so that the same curved surfaces can be brought into sliding contact.

This idea divides the axle box into two parts, the flange member 7 and the axle box member 3, as described above, and creates an uneven curved surface 11.1 with the same radius of curvature.
2 to bring both members into sliding contact and press and fix them using a spring. Even if misalignment occurs between the nut attached to the object to be fed and the male screw, the uneven curved surfaces 11 and 12 will slide and align accurately. The misalignment is immediately corrected.

Furthermore, since no elastic body is interposed between the members 3 and 7, the rigidity in the feeding direction is not impaired at all.

Moreover, since misalignment can be easily corrected, abnormal wear of the contact portion between the nut and male screw and stick-slip caused by abnormal surface pressure are eliminated, making it possible to feed the screw precisely.

Furthermore, it has many excellent effects, such as completely eliminating uneven feed rates due to insufficient rigidity of threaded parts and axle boxes.

If there is a problem in the parallelism between the slide piece (not shown) and the male screw, it is possible to attach the screw 10 for attaching the flange member 7 to the object to be fed 8 via the elastic body 30 as in the embodiment. , the axle box can move in the radial direction.

Therefore, it is possible to easily eliminate a positional defect in parallelism between the slide piece and the male screw.

[Brief explanation of drawings]

Fig. 1 is a sectional view of this embodiment, Fig. 2 is a front view of the same, and Fig. 3 is a sectional view of this embodiment.
The figure is an enlarged view of section A in FIG. 1...Natsuto, 2...Natsuto, 3...
...Axle box member, 4...Male thread, 7...
...Flange member, 8...Object to be sent, 11.
...Concave curved surface, 12...Convex curved surface, 19...
... Spring, 30 ... Elastic body.

Claims (1)

[Scope of utility model registration request] In a feed screw consisting of an axle box fixed to an object to be fed and housing a nut, and a male thread screwed onto the nut, the axle box is composed of two members, a flange member and an axle box member, which are made to face each other, A feed screw nut characterized in that the contact surface is formed into an uneven curved surface with the same radius of curvature, the axle box member is always pressed and fixed to the flange member via a spring, and the contact surface is made slidable. .