JPH048951A - Ball screw adjusting device with plural nuts incorporated - Google Patents

Abstract

PURPOSE:To enable a plurality of ball nuts to equally burden load by fixing an adjustable ball nut at the center position with no play between the side to which the adjustable ball nut comes close to a stationary ball nut and the side where the aforesaid nut is separated from the stationary ball nut in a device including the stationary ball nut, the adjustable ball nut and an adjusting nut. CONSTITUTION:After a stationary ball nut 3 has been fixed on a support member 5, an adjusting nut 8 is continuously rotated to a position where each ball 9 stops playing with a bolt 7 loosened, wherein the position of the indication mark 10 of the support member 5 is thereby recorded on the adjusting nut 8 as a mark 11a. In the second place, the adjusting nut 8 is then fastened into the support member 5, and an adjustable ball nut 4 is brought close to the stationary ball nut 3 with the bolt 7 fastened, so that the adjustable ball nut is thereby positioned where each ball 9 has no play. The adjusting nut 8 is unscrewed, and a mark 11b is recorded on the position of the indication mark 10 at a position where the adjusting nut abuts against the adjustable ball nut 4. The mark 11a and the center position of the mark 11b are made to coincide with the indicated mark 10 with the adjusting nut 8 rotated, and the adjustable ball nut 4 is fastened by the bolt 7 thereafter. This thereby enables each ball nut to equally burden load.

Description

[Detailed description of the invention] Child! BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball screw device, for example, a ball screw device for conveying orbits of a floating linear motor car.

As shown in FIGS. 7 and 8, the orbital switching machine for a linear motor car rotates the screw shaft 103 of a ball screw device 1102 by a drive unit W101, and the ball nut 104 at that time rotates. The movement is transmitted to the connecting rod 105 fixed to the ball nut 104 and the chain 106, and the movement of the chain 106 rotates the sprocket wheel 107, and at the same time, the crank arm 108 fixed to the sprocket wheel 107 rotates. At that time, as shown in FIG. 9, the crank arm 108 is rolled and the track 109
The present applicant has proposed a structure in which the rolling track 109 is moved between the plurality of tracks 110 and 111 by interlocking with the rolling track 109, although this structure is not known publicly.

Since the ball screw device used in such an orbital switching machine for a linear motor car has a large load, the life of the nut is shortened. In order to extend the life of the nut, there is a method of lengthening the nut, but there is a limit to the length, and if it is made longer than the limit, problems with machining, such as machining accuracy, will occur. Therefore, in order to withstand the load and extend the service life, it is necessary to use a plurality of ball nuts.

When two or more ball nuts are installed apart from each other on one screw shaft, there is play between the screw shaft and the ball nut, so the load cannot be shared evenly between the two or more ball nuts. As a result, there was a problem that stress was inevitably placed on the ball nut, shortening its lifespan.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and provide a ball screw device that can evenly share the load using a plurality of ball nuts.

The present invention solves the above problem by providing a ball screw having a screw shaft, a plurality of ball nuts that are threadedly engaged with the screw shaft via balls, and a support member that supports the plurality of ball nuts. In the apparatus, one fixed ball nut is fitted and fixed to the support member, one or more adjustable ball nuts are fitted to the support member so as to be movable in an axial direction, and the ball nuts are screwed into the support member and are connected to an end face of the support member. an adjustment nut formed to be movable between the contact surface of the adjustable ball nut and provided for each adjustable ball nut,
By a ball screw adjusting device assembled with a plurality of nuts, the adjustable ball nut is fixed at a central position between a no-play position on the side approaching the fixed ball nut and a no-play position on the side away from the fixed ball nut. Settled.

The present invention allows a plurality of ball nuts to function as if they were a single ball nut.

According to the present invention, a ball screw device has one fixed ball nut fixed to a support member and at least one adjustable ball nut arranged to be axially movable on the support member and whose position can be adjusted. , each of the adjustable ball nuts has 1
an adjustment nut screwed into each of the support members;
The no-play positions of the adjustable ball nut on both sides approaching and away from the fixed ball nut are detected by scales attached to the adjustable nut, and the two are adjusted to an intermediate position between the no-play positions. The position of the adjustable ball nut is selected and fixed by adjusting the position of the nut and coming into contact with the adjusting nut.

According to the present invention, the plurality of ball nuts engage with the screw shaft with almost equal play in both normal and reverse rotations of the screw shaft, so when the driving force is transmitted by the screw shaft, the plurality of ball nuts It became possible to bear the load almost evenly on the nut.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a track switch for a linear motor car will be described with reference to the drawings.

In FIG. 1, a ball screw device 1 includes one screw shaft 2 and one fixed ball nut 3 screwed into the screw shaft 2.
, at least one adjustable ball nut 4 , in the example shown one adjustable ball nut 4 , and a support member 5 supporting the fixed ball nut 3 and the adjustable ball nut 4 .

The support member 5 is fixed, for example, to a connecting rod 105 (FIGS. 7 and 8) and serves to move a crank arm that moves the point track.

The fixed ball nut 3 is fitted into the support member 5, and the flange portion 3a is fixed to the support member 5 with bolts 6.

The adjustable ball nut 4 is fitted into the support member 5 so as to be movable in the axial direction, and the bolt 7 inserted into the bolt hole of the flange portion 4a of the adjustable ball nut 4 is screwed into the support member 5. Each adjustable ball nut 4 has one adjustable nut 8.
It will be attached to each individual.

The adjusting nut 8 is screwed into the support member 5 and has a flange portion 8a which can bear against the end face of the support member 5 and against the flange portion 4a as the abutment surface of the adjustable ball nut 4. In this example, the adjusting nut 8 is screwed into a threaded portion formed on the outside of the support member 5.
It is also possible to have a screw-in structure.

The screw shaft 2 and ball nuts 3 and 4 are engaged with each other via balls 9.

The screw shaft 2 is rotatably supported by a bearing (not shown),
By being rotationally driven by a drive device (not shown),
The ball nuts 3 and 4 that are engaged with the screw shaft 2 via the balls 9, and therefore the support member 5 that is in a fixed relationship with these ball nuts, are linearly moved in a direction determined according to the rotational direction of the screw shaft 2. .

When assembling the ball screw device 1, after the fixed ball nut 3 is fixed to the support member 5, as shown in FIG.
With the bolt 7 sufficiently loosened, rotate the adjustment nut 8 in the loosening direction, push the adjustable ball nut 4 away from the fixed ball nut 3, and rotate the adjustment nut 8 until the ball 9 has no play and will no longer move. do. At the position where the adjustment nut 8 stops rotating, for example at a distance Q1 from the end surface of the support member 5, as shown in FIG. 8, or write a scale on the adjusting nut 8 in advance, and read the scale indicated by the indicator mark 10.

Next, as shown in FIG.
The adjustable ball nut 4 is moved close to the fixed ball nut 3 by tightening the bolt 7, and the bolt 7 is tightened to the position where the ball 9 has no play and cannot be moved.

In this position there is a distance of, for example, Ω2 between the adjusting nut 8 and the adjustable ball nut 4.

With the adjustable ball nut 4 tightened with the bolt 7, unscrew the adjustable nut 8 as shown in FIG.
As shown in FIG. 5, mark ll
b is written at the position indicated by the indicator mark 10, or the position indicated by the indicator mark 10 is read on the already marked scale.

Thereafter, the adjusting nut 8 is rotated to align the mark 11C at the center position of the marks lla and 11b with the indicated position of the indicator mark 10, and the flange 8 of the adjusting nut 8 is turned at that position.
Tighten the adjustable ball nut 4 with the bolt 7 until the flange 4a comes into contact with the bolt 7.

The assembly method is not limited to the above, but first tighten the bolt 7 with the adjusting nut 8 fully tightened to eliminate any play in the ball, then loosen the adjusting nut 8 and make it contact the adjustable ball nut 4. Mark the position 0 Next, loosen the bolt 7 by about 10 cm, for example, and while the adjustable ball nut 4 is not in contact with the bolt 7, loosen the adjusting nut 8 until the adjustable ball nut 4 stops at the position where there is no more play with the ball. It is also possible to make a mark, then return the adjusting nut 8 to the center position between both marks, and then bring the adjustable ball nut 4 into contact with the adjusting nut 8 and fix it.

For the above example where there is one adjustable ball nut 4,
If there are two or more, the configuration can be as shown in FIG. 6. In this case, in addition to the support members 5 shown in FIG.
One or more of them can be fixed to the support base 5a, and the above-mentioned connecting rod 105 for moving the point track can be fixed to the support base. Alternatively, a structure may be employed in which a plurality of support members for supporting a plurality of adjustable ball nuts are fixed to the support base 5a. It is also possible to configure the plurality of support members 5, 5' as one support member integrally formed with each other, and omit the support base 5a.

In FIG. 6, the screw shaft 2 is rotatably supported by a case 12, and is connected to the output shaft of a drive device 14 via a connecting rod 13 connected by a universal joint, and is rotationally driven.

The support member 5 or the abutment 5a is not directly fixed to the mating member to be reciprocated, for example, the connecting rod 105, as described above, but may be indirectly fixed via another member.

Wheat-Rice According to the present invention, it is possible to appropriately adjust the play of all ball nuts with respect to the balls using two or more ball nuts, and the load can be applied to one screw shaft through a plurality of ball nuts. Moreover, each ball nut can now share the load equally. Therefore, the load capacity of the ball screw device can be more than doubled with the same lifespan, and if the load is the same, the lifespan of the ball screw device can be more than doubled.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the ball screw device according to the present invention, Figs. 2 to 4 are views sequentially explaining the assembly and adjustment process of the adjustable ball nut, and Fig. 5 is an example of marks on the support member and the adjustment nut. FIG. 6 is a schematic diagram showing an example using a plurality of adjustable ball nuts, FIG. 7 is a schematic diagram of a transmission system using a ball screw device of an orbital point machine for a linear motor car, and FIG. 8 is a schematic diagram showing an example of using a plurality of adjustable ball nuts. FIG. 9 is a partially broken pressure surface view of the ball screw device and the drive device, and a plan view of the point machine. 1...Ball screw device 2...Screw shaft 3...Fixed ball nut 3a...
...Flange part 4...Adjustable ball nut 4
a... Plunge portion 5... Support member 7... Bolt 8a... Flange 10... Indication mark 11a... Mark (maximum) 11c... Mark (middle) 12... Case 14... Drive device 6... Bolt 8... Adjustment nut 9 ...Ball 11b...Mark (minimum) 13...Connection

Claims (1)

[Scope of Claims] A ball screw device having a screw shaft, a plurality of ball nuts that are threadedly engaged with the screw shaft via balls, and a support member that supports the plurality of ball nuts, wherein the support member includes: one fixed ball nut fitted and fixed; and one fixed ball nut fitted into the support member so as to be movable in the axial direction.
one or more adjustable ball nuts screwed into the support member and configured to be movable between the end face of the support member and the abutment face of the adjustable ball nuts, one adjustment being assigned to each adjustable ball nut; and a plurality of nuts, the adjustable ball nut being fixed at a central position between a no-play position on the side approaching the fixed ball nut and a no-play position on the side away from the fixed ball nut. ball screw adjustment device.