JPS5836922Y2 - ball screw - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an internal circulation type ball screw using .

Methods for circulating the balls of a ball screw include the screw shaft circulation method, ball tube method, guide plate method, end cap method, and this method, but for ball screws with a relatively small diameter, Due to the limited space available for the pole nut and the difficulties in manufacturing the neck and parts, this type 1 is often used as it is compact and relatively easy to manufacture.

This type 1 has a guide groove added to the pole nut to recirculate the balls over the peak formed between the spiral grooves of the screw shaft, and the ball circulation path is the shortest. Because of this structure, the space required for ball circulation can be minimized.

Conventionally, ball screws using such a pole 1 are known, such as those in which the casing is attached to a pole nut using an adhesive, or those in which the pole 1 is fitted from the inside of the pole nut.

When the case is glued to the pole nut, it is difficult to match the guide groove of the case and the spiral groove of the pole nut correctly.If they do not match, remove this item and re-adhere it, but once it has been glued, There is a drawback that this part cannot be removed easily.

In addition, the adhesive often leaks onto the ball transfer surface from the connection between the pole nut and the trench, and it is necessary to remove unnecessary adhesive after adhesion.Especially with small pole nuts, the workability is poor and requires a lot of man-hours. There are some drawbacks.

Furthermore, when adhesive is used, it is not easy to detect poor adhesion, and there are also accidents in which residue falls off during handling 1, 41 or during use.

If this item 1 is fitted from the inside of the pole nut, it will not fall off during handling, but in the conventional type, the screw shaft or the protrusion that engages with the helical groove of the pole nut prevents the item from falling off. When the screw is stopped, the lock is not completely held, and when the ball crosses the ridge of the screw shaft through the spiral groove of the screw shaft, a moment force acts to rotate the screw. As a result, the guide grooves 1 and 1 are slightly misaligned, which hinders the smooth transfer of the ball.

In addition, this type of assembly requires inserting the lever 1 inside the ball nut, which has the disadvantage that workability is not good, especially when using a small pole nut.

This invention was made in view of the above-mentioned drawbacks, and its purpose is to provide a ball screw that can operate smoothly even with a small diameter ball screw and that can be easily assembled. .

In order to achieve this purpose, this invention provides a trapezoidal groove having an inclined surface that communicates with the surface of the hole of the pole nut in which the pole nut 1 is attached and spreads radially inward of the pole nut. The above object is achieved by fitting and holding the lever 1 by engaging the parts.

Next, an embodiment of this invention will be described with reference to the drawings.

1 is a screw shaft having a spiral groove having an arcuate cross section in the outer cylinder; 2/
Fi is a pole nut with a spiral groove on its inner surface that corresponds to the spiral groove of IJl.

A large number of balls 3 are disposed in the space formed by the corresponding spiral grooves of the screw shaft 1 and the pole nut 2, and as the balls 3 roll and transfer, the screw shaft 1 and the pole nut 2
is capable of spiral movement with relatively little resistance.

The pole nut 2 has a guide groove 5 for recirculating the moving balls 3 by returning them to the adjacent helical grooves along the bright part 4 formed between the helical grooves of the screw shaft 1.
6 is fitted into a hole 7 and a trapezoidal groove 8 provided in the pole nut 2.

The hole 7 of the pole nut 2 is a cylindrical hole, but depending on the dimensions of the helical groove of the screw shaft 1, an elliptical hole may also be adopted.

The trapezoidal groove 8 of the pole nut 2 is for attaching the pole nut 6 in a predetermined position, and is provided to communicate with the hole @ 7 of the pole nut 2, and has a bottom surface 9 parallel to the axis of the pole nut 2.
It has an inclined surface 10 that extends inward in the radial direction of the pole nut 2.

The pole nut 2 is provided with holes 1 having the trapezoidal grooves 8 in the same number as the holes 6 to be used.

child! 6 has a shape that fits into the hole 7 of the pole nut 2 and the trapezoidal groove 8, and has a surface 11 on the side surface that comes into contact with the bottom surface 9 of the trapezoidal groove 8 of the pole nut 2, and a surface 11 of the pole nut 2. It has a cylindrical shape with a protrusion 13 having a surface 12 that abuts on the inclined surface 10 of the trapezoidal groove 8 .

The side surface of the protruding portion 13 of this and 16 is provided with a guide groove 5 of this and 16.
Surface 1 to prevent the ball 3 from rotating when the moving ball 3 crosses the bright part 4 of the screw shaft 1.
4 is provided.

It is not necessarily necessary to provide this surface 14 on the protruding portion 13 of this 16, and such a surface may be provided on the side collapse of this part 6.

In this first embodiment, the head 16 is made of an elastic material such as plastic, and is formed integrally with the protrusion 13 and the length 6.

When assembling the screw and 16 into the pole nut 2, insert the screw and 16 into the hole 7 of the pole nut 2 from the outside of the pole nut 2, and slightly elastically deform the protrusion 13 of the top 6 so that it engages with the trapezoidal groove 8 of the pole nut 2. This is done by

The protrusion 13 of T-6 is designed to provide a slight tightening margin to the trapezoidal groove 8 of the ball nut 20 so that the screw 6 can be securely fixed to the pole nut 2.

FIG. 6 shows the housing 6 of the second embodiment.

In this case, the t6 has an oval shape, and the side surface of the top 6 prevents rotation of the top 6, and the surface 12 for abutting against the inclined surface 10 of the trapezoidal groove 8 of the pole nut 2 is shown in FIG. The direction is perpendicular to 16 and 16.

It is also possible to provide the protrusions 13 and 16 on other side surfaces of this embodiment.

In the ball screw spring of this invention constructed as described above, the bottom surface 9 and the inclined surface 10 of the trapezoidal groove 8 provided in the pole nut 2
Since the surfaces 11 and 12 of the protruding portion 13 of the tooth 16 are brought into contact with each other to fit and hold the head 6, it can be implemented in a compact form even for small diameter ball screws where only a small space is allowed. The mounting position of ball 6 is also accurate, and ball 3 does not move during use, so a smooth circular transfer of ball 3 is achieved, and uneven rotation of the ball screw does not occur.
The housing 6 can be easily assembled from the outside of the pole nut 2 and by utilizing the elasticity of the i6, and there is no need to use adhesive.

Furthermore, since the trapezoidal groove 8 communicating with the hole 7 of the pole nut 2 has an inclined surface 10 that extends inward in the radial direction of the pole nut 2 to fit and hold the ball screw, the ball screw can be used easily. When the tip 16 receives from the circulating ball 3, the protrusion 1 of this 16 responds to the force pushing up i6.
It also has the effect that stress concentration is less likely to occur in the ball screw 3, the protrusion 13 of the ball screw 16 does not suffer from fatigue failure, and the ball screw can withstand long-term use.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing an embodiment of the ball screw of this invention, FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG.
A partial sectional view of the parts taken along line B-B in Figure 2, Figure 4,
5 is a perspective view of the parts of FIG. 1, and FIG. 6 is a perspective view of the parts of the second embodiment. 1...Screw shaft, 2...Ball nut,
3... Ball, 5... Guide groove, 6...
1.7...hole, 8...trapezoidal groove, 13...protrusion.

Claims (1)

[Scope of utility model registration request] It is formed by a screw shaft 1 having a spiral groove with an arcuate cross section on its outer surface, a ball nut 2 having a spiral groove on its inner surface corresponding to the spiral groove of the screw shaft, and corresponding spiral grooves of the screw shaft shaft and pole nut. A ball made of plastic having a large number of balls 3 arranged in a space and a guide groove that allows the balls to be returned to the adjacent spiral or spiral groove along the ridge 4 formed on the screw shaft and recirculated. 16, the pole nut has a hole 1 that cuts out two adjacent spiral grooves of the pole nut.
and a trapezoidal groove 8 having a bottom surface 9 and a sloped surface 10 extending inward in the radial direction of the pole nut, which communicates with the hole, A protrusion 13 having surfaces 11 and 12 that abuts on the bottom surface 9 is provided, and the protrusion 13 is fitted into a trapezoidal groove of the pole nut to hold the pole nut 1. ball screw.