JPS5923892Y2 - Motion direction changing device - Google Patents

Description

[Detailed description of the invention] This invention relates to a movement direction converting device that converts rotational motion into linear motion, which consists of a screw shaft and a nut screwed onto the screw shaft, and particularly to a mechanism that prevents play in the axial direction. It is something.

Fig. 1 is a vertical cross-sectional view showing a conventional motion direction changing device, and Figs. 2 and 3 are partially enlarged views showing the screwed state thereof. , 2 is a nut screwed onto the threaded shaft 1, 3 is a housing that holds the threaded shaft 1 and the nut 2, 4a and 4b are ball bearings that support the threaded shaft 1 in the housing 3, and 5.
Reference numeral 6 indicates a cover that limits the movement of the ball bearing 4b in the axial direction, and 6 indicates a shim that adjusts the gap between the cover 5 and the ball bearing 4b.

Next, the operation will be explained.

As the screw shaft 1 supported by the ball bearings 4a and 4b rotates, the nut 2 whose movement in the rotational direction is blocked moves linearly in the lateral direction.

When a load is applied to nut 2 in the tensile direction, nut 2
The relative position of the screw shaft 1 and the screw 1a is as shown in FIG. 2, and the movement of the screw shaft 1 in the tensile direction is restricted by the housing 3 and the ball bearing 4a.

Furthermore, when a load is applied to the nut 2 in the pushing direction, the relative position between the nut 2 and the screw 1a becomes as shown in FIG. is limited.

The conventional motion direction converting device for converting rotational motion into a linear motion direction is configured as described above, so that when the direction of the load applied to the nut 2 is not constant, the screw 1a and the nut 2
The amount of clearance appears as axial play.

Furthermore, even if you try to increase the accuracy of each individual part to sufficiently reduce backlash, if the temperature range used is wide, if the nut 2 and screw shaft 1 have different expansion coefficients, the nut 2 and screw 1a will necessarily match. A gap was required between the two, which had the disadvantage that the occurrence of rattling could not be completely prevented.

This invention was made in order to eliminate the drawbacks of the conventional ones as mentioned above, and by inserting a spring between the nut and the attached nut, the positional relationship between the nut and the screw is kept constant, and the nut and screw are fixed. It is an object of the present invention to provide a motion direction changing device that does not have an effect on axial play due to the gap created between screws and is equipped with an axial play prevention mechanism.

An embodiment of this invention will be described below with reference to the drawings.

Fig. 4 is a vertical sectional view of the embodiment, Fig. 5 is a partially enlarged view showing the screwed state, and Fig. 6 is an exploded perspective view. The corresponding parts are shown, and 7 is an added nut that has an external spline 7a on the outer periphery and is screwed onto the screw shaft 1, and 8 is a coil spring that applies an axial load to the nut 2 and the attached nut 7. be.

Further, the nut 2 is formed with an internal spline 2a that fits into the external spline 7a.

Next, the operation will be explained.

As the screw shaft 1 supported by the ball bearing 4a rotates, the nut 2 whose rotational movement is blocked and the added nut 7 connected to the nut 2 by a spline move linearly.

In this case, the normal relationship between the nut 2 and the screw shaft 1 is as shown in FIG. 5, and play is prevented from occurring.

When a pushing load greater than the set load of the coil spring 8 is applied to the nut 2, the added nut 7 and the nut 2 are allowed to move in the axial direction. can move in any direction.

Further, even if the screw 1a and the nut 2 are worn out, the state shown in FIG. 5 is always maintained by the coil spring 8.

Furthermore, the set load can be adjusted within a very small range because the lead length of the screw can be equally divided by the number of teeth of the spline.

In the above embodiment, the axial load was obtained by a coil spring, but a flat spring may also be used. In this case, the set load can be increased, and the device can be made smaller and lighter.

As described above, according to this invention, a spring is inserted between the nuts connected by splines, and the positional relationship between the nut and the screw shaft is fixed by the spring, so that the gap between the screw and the nut is This has the effect of preventing directional wobble.

[Brief explanation of drawings]

Fig. 1 is a partial vertical sectional view showing a conventional motion direction conversion device for converting rotational motion into linear motion, Figs. 2 and 3 are partially enlarged views thereof, and Fig. 4 is a rotation according to an embodiment of this invention. FIG. 5 is a partial vertical sectional view showing a motion direction converting device for converting motion into linear motion, FIG. 5 is a partially enlarged view thereof, and FIG. 6 is an exploded perspective view of the main parts. In addition, in the figures, the same reference numerals indicate the same or corresponding parts, and 1
is the screw shaft, 2 is the nut, 3 is /'% uzing, 4a, 4
b is a ball bearing, 5 is a cover, 6 is a shim, 7 is an added nut, and 8 is a coil spring.

Claims (1)

[Scope of utility model registration request] A motion direction conversion device for converting rotational motion into linear motion, comprising a threaded shaft formed with a groove and a nut threaded onto the threaded shaft, which is connected to the nut by a spline and threaded onto the threaded shaft. A device for changing the direction of motion, characterized in that it comprises a nut attached to the nut, and a spring inserted between the two nuts.