JPH08326864A - Linear driver - Google Patents

Abstract

PURPOSE: To aim at miniaturization o a linear driver by arranging a hollow spline coaxially with a ball screw shaft integrally connected to the output shaft of a rotational drive source, screwing a nut fixed to the inside of the spline to the ball screw and fitting a spline nut around the outer circumference of the spline. CONSTITUTION: A rotational driving source 3 such as a motor is fixed to bracket 2 whose section is in a shape of a one-side missing square and which is fixed to a base 1 and ball screw shaft 7 on which a spiral groove 6, is formed is connected to the output shaft 4 of the rotational driving source 3 through a coupling 5. Also a fixing member 9 to which a spline nut is fixed is fixed to the base 1, and a spline shaft 11 in which a hollow part 10 is formed is inserted and set in a stop line nut 8 by allowing only sliding motion. A nut 12 in which the ball screw shaft 7 is screwed is fixed to one end part of the hollow part 10 of the spline shaft 11. Thus, the spline shaft 11 is moved by means of the rotation of the ball screw shaft 7 caused by the operation of the rotational driving source 3 so that a work or an arm etc., arranged on the end part of the spline shaft 11 is linearly moved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Further, the present invention relates to a linear drive device for vertically moving an arm or a work in an articulated robot or the like.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. It is a work lifting device. A rotation drive source 102 is provided on the base 101.
Has been fixed. A ball screw shaft 103 is rotatably mounted in parallel with the rotary drive source 102. The rotary drive source 102 and the ball screw shaft 103 have a pulley 105 and a belt 106 to which a nut 104 is fixed.
Are linked by. Also, the ball screw shaft 1
A spline shaft 108 is fixed to one end of 03 through a coupling 107. The spline shaft 108 is non-rotatably attached by a spline nut 109 fixed to the base 101 so that it can slide. Reference numeral 110 is a bracket for fixing a mounting table for holding the work fixed on the top of the spline shaft 108.

[0003]

However, in the above prior art, the ball screw shaft 103 and the spline shaft 1 are
Since the 08s are connected in a straight line, the entire length becomes long and the device itself becomes large.

Here, the spline shaft 1 is provided through the rotary drive source 102, the ball screw shaft 103, the connecting member and the like.
It is conceivable to install 08 in parallel, but the length can be shortened and the width becomes large, which also makes the entire device large.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and to integrally connect a ball screw shaft to an output shaft of a rotary drive source and to form a hollow spline coaxially with the ball screw shaft. It is characterized in that a nut fixed to the inside of the spline and a ball screw are screwed together, and a spline nut that prevents rotation of the spline and allows only sliding is inserted and fixed to the outer periphery of the spline.

[0006]

EXAMPLE An example will be described with reference to FIG. A U-shaped bracket 2 is fixed to the base 1, and a rotary drive source 3 such as a motor is fixed to the bracket 2. Further, a ball screw shaft 7 having a spiral groove 6 formed outside is fixed to an output shaft 4 of the rotary drive source 3 via a coupling 5.

On the other hand, a fixing member 9 for fixing the spline nut 8 is fixed to the base 1. A spline shaft 11 having a hollow portion 10 is slidably attached to the spline nut 8 so as not to rotate. Further, a nut 12 screwed with the ball screw shaft 7 is fixed to one end of the hollow portion 10 of the spline shaft 11. That is, the ball screw shaft 7 is located in the hollow portion 10 of the spline shaft 11.

Next, the operation will be described. Rotation drive source 3
When the power is turned on, the output shaft 4 rotates and the output shaft 4
The ball screw shaft 7 also rotates with the rotation. Then, the rotation of the ball screw shaft 7 is transmitted to the spline shaft 11 via the nut 12, but since the spline shaft 11 is non-rotatably attached by the spline nut 8, it does not rotate and the spline nut 8 Slide (move) on the inner surface of. By the movement of the spline shaft 11, a work, an arm, a work tool or the like arranged at the end of the spline shaft 11 linearly slides and moves to a predetermined position.

[0009]

According to the present invention, a ball screw shaft is integrally connected to an output shaft of a rotary drive source, a hollow spline is arranged coaxially with the ball screw shaft, and a nut and a ball fixed inside the spline. Since a screw is screwed and a spline nut that prevents rotation of the spline and allows only sliding is inserted and fixed to the outer periphery of the spline, the device itself can be made small.

[Brief description of drawings]

FIG. 1 is a cutaway front view of an essential part of an embodiment of the present invention.

FIG. 2 is a front view of a conventional device.

[Explanation of symbols]

 1 Base 2 Bracket 3 Rotational Drive Source 4 Output Shaft 5 Coupling 7 Ball Screw Shaft 8 Spline Nut 10 Hollow Part 11 Spline Shaft 12 Nut

Claims (1)

[Claims] 1. A ball screw shaft is integrally connected to an output shaft of a rotary drive source, a hollow spline is arranged coaxially with the ball screw shaft, and a nut and a ball screw fixed inside the spline are screwed together. A linear drive device is characterized in that a spline nut that prevents rotation of the spline and allows only sliding is inserted and fixed on the outer periphery of the spline.