JPS5925542A - Rectilinear type motor actuator - Google Patents

Abstract

PURPOSE:To eliminate the need for a rectilinear mechanism set up externally and a coupling by incorporating a screw mechanism into the rotor of the motor actuator. CONSTITUTION:A nut 16, which is fixed onto the same shaft as the rotor and on the inner diameter side thereof a screw groove is formed, is set up to the inner diameter section of a rotor magnet or a rotor core 13, and a screw shaft 17 is fitted to the nut 16. The section B of the screw shaft 17 takes a non-circle, and a ring 18 for a detent of the shaft fixed to a bracket 12b is fitted to the section B of the screw shaft 17 at a proper clearance. When exciting a stator 10, the rotor magnet or the rotor core 13 and the nut 16 are turned. The screw shaft 17 fitted to the nut 16 is moved in the axial direction with the revolution of the nut 16 because the detent is executed by the ring 18 in the section B.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a motor actuator with a built-in linear movement mechanism, and an object thereof is to provide a small and inexpensive linear movement motor actuator.

Conventional configuration and its problems An example of a motor actuator with a conventional linear movement mechanism is shown in FIGS. 1 and 2. 1 is a drive motor such as a pulse motor or a DC servo motor, 2 is an output shaft, 3 is a ball screw screw/yaft, and 4 is the output shaft 2 and screw shaft 7.
6 is a nut part of a ball screw, 6 is a bearing for fixing one end of the spring shaft 5, 7 is a bearing housing for fixing the bearing 6, 8 is a shaft for straight movement For example, X
-It is a stand for Y tape. 9 is a guider for the object to be moved 9
It's a stop.

However, in the configuration of the conventional example described above, the motor section and the linear movement mechanism section are made separately and connected by a compression ring.
A minimum amount of space is required for the linear movement mechanism, and space for the coupling section is also required. This coupling space tends to become relatively larger as the output becomes smaller. Furthermore, a mechanism for preventing rotation of the nut and the object to be moved is also required. Even from a material cost perspective,
Bearings, linear guiders, and couplings for the linear movement mechanism are required and are expensive.

The present invention eliminates the drawbacks of the above-mentioned conventional example, and incorporates a linear movement mechanism into the motor actuator to improve e
- The aim is to share parts between the actuator and the linear movement mechanism, thereby providing a compact and inexpensive linear movement motor actuator.

DESCRIPTION OF EMBODIMENTS FIG. 3 shows an example of a linear actuator according to the present invention, in which 10 is a stator, 11 is a housing that holds the stator, 12a and 12b are end brackets, 13 is a rotor magnet or rotor core, and 14 is the above-mentioned member. A rotor pipe for holding the rotor magnet or rotor core 13 with bearings IE5a and 15b, 16 is a nut with a threaded groove on the inner diameter side, 17 is a threaded shaft that fits into the nut,
The part B in the figure is non-circular. Reference numeral 18 denotes a ring which is fitted with the above-mentioned threaded shaft 170B portion with a proper rear balance and is fixed to the placket 12b to prevent rotation of the shaft, and is made of a sintered alloy or the like. Reference numeral 19 denotes a cap for preventing removal in the axial direction, and is fixed to the tip of the threaded shaft 17.

FIGS. 4 and 5 are cross sections taken along the line AA' in FIG. 2, and show examples in which a D cut and an H cut are made as the screw/gift 8-part shape, respectively. The operation of the actuator will be explained below with reference to FIG. When the stator 1o is appropriately excited by a drive circuit (not shown), the rotor magnet or rotor core 13 generates torque and rotates. Along with this, the rotor holding vibrator 14 and the nut 16 also rotate together.

The threaded shaft fitted into the nut 16 moves in the axial direction as the nut 16 rotates, since the ring 18 prevents rotation at the portion B in the figure.

Here, the thrust force f of the screw/yaft is expressed as. Here, T represents the monitor torque, P represents the thread pitch, and η represents the rebound efficiency.

Effects of the Invention As described above, the present invention incorporates a screw mechanism inside the rotor of a motor actuator, thereby eliminating the need for an external linear movement mechanism or coupling, and greatly increasing the external dimensions of a linear movement type motor actuator. It can be reduced to In addition, the bearings of the motor and the linear movement mechanism can be shared, eliminating the need for a motor shaft or coupling, and furthermore, it is possible to create a simple screw shaft rotation prevention mechanism using the motor member, which has a very large cost advantage.

Moreover, this linear motor actuator is expected to be used for robot hands, automobile engine control, etc., and its industrial value in terms of space and cost is extremely large.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a motor actuator connected to a conventional linear movement mechanism, Fig. 2 is a sectional view of an object to be moved by the motor actuator, and Fig. 3 is a diagram of a motor actuator according to an embodiment of the present invention. 4 is a partial sectional view taken along line A-A/ of the layer α, and FIG. 5 is a sectional view of another embodiment of the spring shaft. 12b... End bracket, 13... Rotor magnet or rotor core, 16... Nut, 17... Screw/yaft, 18... Ring. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 235

Claims (1)

[Claims] A NAND is fixed to the inner diameter of the rotor magnet or the rotor core on a concentric axis with the rotor and has a threaded groove on the inner diameter side, and is fitted into this nut and has a non-circular part in part, and has a reciprocating path. A possible screw shaft and a non-circular part of this screw shaft 71.