JPH10257715A - Method of driving ball screw spline shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rotate a spline nut and a screw nut only with one motor, by driving a ball screw spline with only one motor, using a differential gear mechanism of two output shafts with one input shaft as a deceleration or direct coupling mechanism. SOLUTION: When a motor 5 is operated after being put in such condition that the second output shaft 28 does not rotate by working the second brake 41, the first output shaft 24 and a gear 33 rotate through each gear 26 and 27, and a screw nut 3 rotates through a gear 34, and a ball screw spline shaft 2 shifts axially. Moreover, when it is put in such condition that the first output shaft 24 does not rotate by operating the first brake 40, the output shaft 28 and the gear 29 rotate, and when only the spline nut 4 rotates through gears 31 and 32, the shaft 2 shifts axially and it performs axial rotation, according to the lead of the screw. Accordingly, the selective driving of the screw nut 3 and the spline nut 4 can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving method for a ball screw spline shaft, and more particularly to a method for driving a spline nut and a screw nut by using only one motor by using a differential gear mechanism of one input shaft and two output shafts. A new improvement for rotation.

[0002]

2. Description of the Related Art As a conventional method of driving a ball screw spline shaft of this type, for example, a method shown in FIG. 6 has been employed. That is, what is indicated by reference numeral 1 in FIG. 6 is a mounting table that holds the ball screw spline shaft 2 via the ball screw nut 3 and the spline nut 4 so as to be able to move in the axial direction and rotate freely. Is provided with a ball screw input motor 5 and a spline input motor 6. The rotation of the ball screw input motor 5 is connected to the ball screw nut 3 via a pair of first pulleys 7 and a first belt 8, and the rotation of the spline input motor 6 is controlled by a pair of second pulleys 9 and The spline nut 4 is connected via a belt 10.

Next, the operation will be described. First, when the ball screw nut 3 is rotated by driving the ball screw input motor 5, the ball screw spline shaft 2 can be arbitrarily moved in the axial direction within the range of the stroke A, and the chuck provided at the lower end of the shaft 2 11 can be moved as indicated by the dotted line. Next, when only the spline input motor 6 is driven and only the spline nut 4 is rotated while the ball screw input motor 5 is stopped, the shaft rotates with the axial movement corresponding to the lead of the screw. be able to.

[0004]

The conventional method of driving a ball screw spline shaft has the following problems because it is configured as described above. That is,
Since the ball screw nut and the spline nut are driven using separate motors, two motors are required, which leads to an increase in cost and space, and it has been difficult to meet user requirements.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in particular, a spline nut and a screw can be formed using only one motor by using a differential gear mechanism of one input shaft and two output shafts. It is an object of the present invention to provide a method of driving a ball screw spline shaft that rotates a nut.

[0006]

A method of driving a ball screw spline shaft according to the present invention is directed to a ball screw spline shaft via a spline nut and a screw nut connected to a deceleration or direct connection (reduction) mechanism for reducing the rotation of a motor. In a driving method of a ball screw spline shaft for transmitting and rotating in the axial direction and rotating the shaft, a differential gear mechanism having one input shaft and two output shafts is used as the reduction or direct coupling mechanism, and the ball is driven by only one motor. This is a method of driving a screw spline.

Further, the one input shaft and the two output shafts are connected via a spur gear, and each of the output shafts can be selectively stopped by a brake.
The output shaft is connected via a bevel gear, and each of the output shafts can be selectively stopped by a brake. Further, the first input shaft and the second output shaft are connected via a planetary gear, and each of the output shafts is connected. The shaft is a method that can be selectively stopped by a brake.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for driving a ball screw spline shaft according to the present invention will be described below with reference to the drawings. Note that the same or equivalent parts as those in the conventional example will be described using the same reference numerals. In FIG. 1, reference numeral 1 designates a mounting body provided with only a motor 5 having a first rotation detector 20. At a substantially central position of the mounting body 1, a one-input shaft two-output shaft type differential is provided. A gear mechanism 21 is provided as a speed reduction mechanism. It is also possible to use a direct connection mechanism without deceleration. This differential gear mechanism 21
As shown in FIGS. 2 and 3, the first gear 23 of the input shaft 22, which is one input shaft (one input shaft) connected to the motor 5, is a second gear of the first output shaft 24.
The first output shaft 28 is formed of a box having the first and second connection gears 26 and 27 meshed with the respective gears 23 and 25 so as to rotate freely. , 2
4 is provided coaxially. A third connection gear 29 formed at one end of the second output shaft 28 is provided with a second rotation detector 30 on the mounting body 1 and a fourth connection gear 3 rotatably provided.
And a fifth connection gear 32 coupled to a spline nut 4 provided coaxially with a ball screw spline shaft 2 provided on the mounting body 1 so as to be rotatable and axially movable. Are engaged. Accordingly, the output shafts 24 and 28 constitute two output shafts, ie, two output shafts, and the gears 23, 25, 26 and 27 constitute spur gears.

A sixth connecting gear 33 provided on the first output shaft 24 is provided with a seventh connecting gear 34 of a spline nut 3 provided on the main body 1 and provided coaxially with the ball screw spline shaft 2 and a timing belt 35. Connected by The mounting body 1 is provided with first and second brakes 40, 41 for stopping the rotation of the output shafts 24, 28.

Next, the operation will be described. First, when the motor 5 is operated in a state where the second brake 41 is operated and the second output shaft 28 is not rotated, the first output shaft 24 and the gear 33 are rotated via the gears 26 and 27, and the gear 34 is rotated. The screw nut 3 rotates through the shaft, and the ball screw spline shaft 2 moves in the axial direction. In this case, since the spline nut 4 is stopped, the rotation of the shaft 2 is suppressed. When the first brake 40 is actuated and the first output shaft 24 does not rotate, the output shaft 28 and the gear 29 rotate, and when only the spline nut 4 rotates through the gears 31 and 32, the screw nut 3 Is stopped, the shaft 2 rotates with the axial movement in accordance with the lead of the screw. Therefore, the screw nut 3 and the spline nut 4 can be selectively driven by only one motor 5.

In the above-described embodiment, the case where the differential gear mechanism 21 is constituted by spur gears has been described. A configuration using the planetary gear 70 can be adopted. Note that the same reference numerals are given to the same parts as those in FIG. Although each of the output shafts 24 and 28 is mechanically displaced relative to the input shaft 22, the output shafts 24 and 28 can be arithmetically corrected by a sensor provided on one of the output shafts. Further, the same operation can be obtained regardless of which of the output shaft and the input shaft is used as the input shaft and the output shaft.

[0012]

The method of driving a ball screw spline shaft according to the present invention is configured as described above.
The following effects can be obtained. That is, since the rotation of one motor is transmitted to the spline nut and the screw nut using a differential gear mechanism of one input shaft and two output shafts, two motors are not required as in the related art, and one motor is used. The same function can be achieved with a single motor, and the need for miniaturization can be sufficiently satisfied. Further, since the number of motors and motor drivers is reduced to 1 second, significant cost reduction can be achieved. In addition, since a switching mechanism is not required as compared with a switching mechanism using a gear and a clutch, the occurrence of meshing shift or the like does not occur, and the switching time is short and high durability is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a driving method of a ball screw spline shaft according to the present invention.

FIG. 2 is a sectional view showing the differential gear mechanism of FIG.

FIG. 3 is a perspective view of a main part of FIG. 2;

FIG. 4 is a sectional view showing another differential gear mechanism shown in FIG. 2;

FIG. 5 is a sectional view showing another differential gear mechanism of FIG. 2;

FIG. 6 is a configuration diagram showing a conventional configuration.

[Explanation of symbols]

 2 ball screw spline shaft 3 screw nut 4 spline nut 5 motor 21 differential gear mechanism 22 1 input shaft (input shaft) 24, 28 2 input shaft (first and second input shaft)

Claims (4)

[Claims] A spline nut (4) and a screw nut (3) connected to a mechanism for reducing or directly rotating the motor (5).
In the driving method of the ball screw spline shaft which is transmitted to the ball screw spline shaft (2) through the shaft and axially moved and rotated, the one input shaft (22) and the two output shafts (24 And 28), wherein the ball screw spline shaft (2) is driven by only one motor (5) using the differential gear mechanism (21). 2. The one input shaft (22) and the two output shafts (24, 28) are connected via spur gears (23, 25, 26, 27), and the output shafts (24, 28) are braked. 2. The method of driving a ball screw spline shaft according to claim 1, wherein the stop can be selectively performed by (40, 41). 3. The one input shaft (22) and the two output shafts (24, 28) are connected via a bevel gear (60), and the respective output shafts (24, 2) are connected.
8. The method of driving a ball screw spline shaft according to claim 1, wherein the step (8) can be selectively stopped by a brake (40, 41). 4. The one input shaft (22) and the two output shafts (24, 28) are connected via a planetary gear (70), and the output shafts (24, 28) are connected.
2. The method of driving a ball screw spline shaft according to claim 1, wherein the brake can be selectively stopped by a brake (40, 41).