JPS631851A - Method of cooling feed-secrew-shaft of straight-line-motion-generating mechanism - Google Patents

Abstract

PURPOSE:To obtain a sufficient cooling effect without using a rotating sealed-joint, by providing a through hole, through which the cooling fluid passes, to the inner part of a screw shaft, whose both ends are fixed to a base table and which is threadedly engaged with a nut in such a manner that the nut can freely rotate. CONSTITUTION:Both ends of a sliding screw shaft or a ball screw shaft 2 are fixed to a base table 1. A rotor 3 of a motor M is threadedly engaged with the shaft 2 by means of a nut 4 in a freely rotatable manner. Meanwhile, a stator 6 fixed to a moving main body 7 is loosely fitted to the periphery of the rotor 5 fixed to a rotor shaft 3, thereby converting the rotational force of the motor M into a straight- line motion of the moving main body 7. A through hole 8 for the cooling liquid is made inside the screw shaft 2 in the axial direction, so that the fluid is introduced from an inlet port 9 and is discharged from an outlet port 10. With this contrivance, a high pressure fluid can be used because this mechanism does not need a rotating sealed-joint for the fluid. In addition, the diameter of the through hole 8 can be increased, thereby enlarging the heat transfer area. Therefore, it becomes possible to suck in the outdoor air as it is for cooling.

Description

[Detailed description of the invention] [Object of the invention] (Industrial use!) This invention is based on the patent application No. 61-625 previously filed by the applicant.
No. 67 and Japanese Patent Application No. 61-62668 and Japanese Patent Application No. 1983
- In the linear motion generating mechanism according to the invention disclosed in No. 102814, etc., a hollow through hole for cooling fluid circulation is bored in the axial direction inside the sliding screw shaft or ball screw shaft that is the center of the moving body that performs linear motion. The present invention relates to a forced cooling method for a motor feed screw shaft of a linear motion generating mechanism, which has a fluid inlet and an outlet at both ends thereof.

(Prior Art) Conventional methods for cooling electric motors generally involve attaching a fan to the rotor shaft and stirring and circulating indoor air to cool the motor, or installing a fan outside the electric motor to cool the motor from the outside. In addition, oil cooling of the feed screw device in conventional linear motion generators in which an electric motor is installed externally has been used in some cases.
(See Figure 2) Large holes cannot be drilled, and forced hydraulic pressure is used to
Moreover, since the feed screw shaft rotates, oil leakage from the oil seal is a major problem.

[Structure of the invention]

(Means for Solving the Problems) Therefore, this invention is completely different from the conventional device in that a movable body with a built-in electric motor moves on the feed screw shaft. Since there is no need for special rotary seal joints at the inflow and outflow portions of the fluid, forced cooling can be performed extremely easily.

(Example) One embodiment of the present invention will be described below with reference to the drawings (Fig. 1).
A rotor shaft (3) of an electric motor (goods) is rotatably screwed onto the screw shaft (2) with a nut (4), and a rotor (3) fixed to the rotor shaft (3) is fixed at both ends. 5), a stator (6) is loosely fitted around the movable body (7), and a moving body (7) is formed outside the stator (6) to transfer the rotational force of one electric boat to the linear movement of the moving body (7). In the linear interlock generation mechanism that converts into
) is bored in the axial direction, and a fluid inlet (9) and an outlet υO are provided at both ends of the feed screw shaft.

(Operations and Effects) As explained above, the present invention differs from the conventional linear motion generation mechanism using an externally installed electric motor as shown in FIG. The rotary seal for fluid does not require a joint and is a fixed seal, so it can withstand high-pressure fluid use. In addition, the rotor shaft of the electric motor of this device has a through hole (8) that has sufficient rigidity and strength in the thick shaft, which is about twice the diameter specified by the conventional JI8 standard, so that in addition to oil cooling, outside air can be used as a refrigerant. It can be sucked in and cooled by the air itself, and the thick shaft increases the heat dissipation area of the rotating parts, increasing the cooling effect, reducing the number of parts, making it more compact, and making maintenance management easier. This is a cooling method for the feed screw shaft that exhibits the following effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, and FIG. 2 is a diagram showing an implementation of a conventional device.

Claims (1)

[Claims] Both ends of a sliding screw shaft or a ball screw shaft are fixed to the base, and the rotor shaft of the electric motor is rotatably screwed onto the shaft with a nut. Also, a stator is installed around the rotor fixed to the rotor shaft. In a linear motion generating mechanism in which a movable body is loosely fitted to the stator and converts the rotational force of the rotor of the electric motor into linear motion of the movable body, a cooling fluid is distributed inside the screw shaft. A method for cooling a feed screw shaft of a linear interlock generation mechanism, which comprises a through hole drilled in the axial direction, and a fluid inlet and outlet provided at both ends of the feed screw shaft.