JPS6030511Y2 - ball screw - Google Patents

Description

[Detailed explanation of the idea] This idea is related to the improvement and creation of a ball screw.

That is, the shaft 1 and the nut 2 are screwed together by male and female threads and screws lln, 2n, and between the threads and thread grooves n, 2n, balls B of minute diameter can be transferred as a group in a row. A ball screw is formed by providing a gap g, interposing countless balls B of minute diameter in the gap g, and shaping the cross-sectional shape of the return tube 3 into a shape that matches the gap g between the thread threads and the thread grooves 1n and 2n. This is what I did.

The minute diameter ball of this invention is preferably one with a diameter as small as technically permissible, but in the case of implementing this invention, a ball of about 1 MIt to 2 m is used. .

The purpose of this invention is to minimize the gaps that occur when the balls in the ball screw come off the thread groove and enter the return tube, and when the balls in the return tube are bitten into the thread groove. be.

In conventional ball screws, grooves are formed in the shaft and nut to hold approximately half of the balls, and because the balls are interposed in the grooves, balls with minute diameters cannot be used due to the structure. Since the balls roll in a single line within the ball group, the impact generated when the balls move in and out of the return tube is also quite large.

The low-impact ball screw contemplated by this invention is a response to the high performance requirements of certain electronic equipment manufacturing equipment, etc., which are currently rapidly progressing.

When a large number of balls with minute diameters are simultaneously dispersed and moved in and out of the return tube as in this invention, the impact is dispersed individually, creating a flow similar to that of an oil film. This makes it possible to create a ball screw that is invisible and causes less impact.

Also, in terms of force transmission, since the structure is such that the characteristics of a ball screw are added to the conventional sliding screw, it exhibits an effect comparable to that of a conventional ball screw.

The shape of the return tube is also different from conventional tubes with a circular cross-section; it is shaped like an ellipse so that balls with minute diameters can be moved in rows, and the entrance and exit of the balls are also threaded. It matches the gap between the screw grooves and is configured to allow transfer within the ball with plenty of room, so that there is no hindrance to the transfer of the ball.

Embodiment - The shaft 1 and the nut 2 are formed with male and female threads and thread grooves 1n92n having an arcuate cross-section.

In this case, the threads and thread grooves In, 2n are the shaft 1
Alternatively, either side of the nut 2 may be concave or convex, whichever is more convenient for processing.

(See FIGS. 2 and 4) In this embodiment, the shaft 1 is provided with a convex male screw thread 1n.

The diameter of the ball B used is 2 mm.

Therefore, the gap g between the screw thread and the screw iln, 2n is set to the diameter of the ball B mentioned above.

On the other hand, the gap (Δ) between the outer diameter of the shaft and the inner diameter of the nut between the respective thread grooves of the nut 2 is made smaller than the ball diameter, so that the ball B does not short-circuit and flow between the respective thread grooves.

A return tube 3 is attached to one side of the nut 2 like a conventional ball screw with its opening positioned at the start and end points of a thread groove, and its cross-sectional shape is approximately an ellipse, which is a crushed circle.

In addition, 4 in the figure is a return tube suppressor.

In the gap g of the ball screw, an infinite number of balls B are housed in groups in rows in the nut 2, the threaded groove 2n, and the return tube 3.

Therefore, the ball screw in this embodiment has shaft 1 and nut 2.
Because of the relative motion of the balls B in the nut thread groove, they roll through the gap g as a group in a row, so when they roll from the thread groove into the return tube 3 and when they are bitten into the thread groove by the return tube 3, The impact will be minimal.

Embodiment 2 As shown in FIG. 6, in this embodiment, the male screw thread 1n' of the shaft 1' is trapezoidal, and the nut 2' is also trapezoidal in accordance with this.

The rest of the structure is the same as the first embodiment, so details will be omitted.

[Brief explanation of the drawing]

The attached drawings show a ball screw of this invention, and FIG. 1 is a front view of the ball screw in which the thread of the shaft is convex and the thread groove of the nut is concave in the first embodiment, FIG. 3 is a cross-sectional view of the same as above, FIG. 4 is a side sectional view of the ball screw in which the thread groove of the shaft is concave and the thread of the nut is convex in the first embodiment. FIG. 5 is a perspective view of the return tube. FIG. 6 is a side sectional view of the second embodiment. In addition, the symbols 1, 1' in the figure...shaft, 2, 2'
... Nut, Int 2n ... Male and female thread groove, G ... Curved gap, 3 ... Return tube, 4 ... Return tube hold down, B ... ...
...It's a ball.

Claims (1)

[Scope of claim for utility model registration] 1 Shaft 1 and nut 2 have male and female threads and thread grooves 1n
Screwed together by +2n, the screw thread and thread groove n, 2n
A gap g is provided in between, in which balls B with minute diameters can be transferred as a group in a row, and in this gap g, countless balls B with minute diameters are disposed.
The ball screw is formed into a shape that matches the threads of the cross-sectional shape of the return tube 3 and the gaps g between the thread grooves In and 2n. 2. The ball screw according to claim 1, wherein the male and female threads and the thread groove Int2n have an arcuate cross-section. 3 The cross-sectional shape of the male and female screw threads and thread grooves is trapezoid 1.
0' The ball screw according to claim 1 of the utility model registration claim.