JPH04161034A - Spindle motor - Google Patents

Abstract

PURPOSE:To save a spindle head cylinder and a cylinder of prior art, decrease the number of parts and assembly manhour, reduce weight, and make a compact motor by fastening the stator of the spindle motor directly to the housing of a spindle head. CONSTITUTION:The stator 23 of a spindle motor 21 is fastened to the front housing 26 and rear housing 27 of a spindle head 25 through fixation flanges 30 and 31. The stator 23 has longitudinal cooling medium passage through holes 32 in the four corners of the outer periphery. The passage holes 32 are connected to the air introduction port 33 of one fixation flange 30 and to the annular path 35 of the rear housing 27 through the passage hole 34 of the other fixation flange 31 and the annular path 35 is connected to the air suction port 37 of a fan 36 on the rear housing 27.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the structure of a so-called built-in spindle motor that is incorporated into the spindle head of a machine tool.

BACKGROUND OF THE INVENTION Generally, this type of main shaft motor has a structure as shown in FIG. A rotor 2 of a spindle motor 1 is integrated into a spindle 4, and the spindle 4 is supported by a front housing 6 and a rear housing 7 of a spindle head 5 via bearings 8 and 9. The front housing 6 and the rear housing 7 are fixed to both ends of a spindle head cylinder 10 that forms the main body of the spindle head 5. on the other hand,
The stator 3 of the main shaft motor 1 has cooling fins 12 on its outer periphery.
The cylinder 11 is fitted and fixed in a cylinder 11 having a cylindrical shape by a fixing means such as an interference fit, and the cylinder 11 is fitted and attached to the spindle head cylinder body 10, and the outer circumference of the cylinder 11 and the spindle head cylinder body 10 are fitted and fixed.
A jacket 13 is formed between the stator 3 and the inner periphery of the stator 3, and the stator 3 is cooled by passing a cooling liquid or air through the jacket 13.

Problems to be Solved by the Invention However, in the above conventional main shaft motor, the stator 3 is connected to the cylinder 1.
Since it has a triple structure in which the cylinder 11 is fitted and fixed to the spindle head body 10, the number of parts and assembly steps are increased, and the spindle head as a whole becomes heavy and large. was there. In addition, liquid cooling or air cooling performed through the jacket 3 does not directly cool the stator 3, but indirectly cools the stator 3 through the cylinder 11, which has the disadvantage of low cooling efficiency.

In addition, liquid cooling requires an oil cooler, piping parts, sealing material, etc., and further requires maintenance and inspection and running costs for operating the oil cooler. On the other hand, if you try to use "C air cooling instead of liquid cooling, you will need an air flow rate ten times higher than liquid cooling due to the difference in specific heat between the liquid and air, and because it is indirect cooling via the cylinder 11, The same I-jacket structure as in the case of liquid cooling had the disadvantage that a sufficient flow rate could not be ensured.

The present invention solves the above problems, and the stator is mounted using a built-in type that simplifies the structure and reduces the number of parts, reduces weight and makes it more compact, and at the same time allows direct cooling of the stator. The purpose is to provide a spindle motor for.

Means for Solving the Problems In order to achieve the above object, the present invention provides a stator that is directly fixed to the housing of the spindle head, and that cooling medium circulation holes are provided in the outer periphery of the stator. Features.

It is preferable that the communication holes are provided at four corners of the outer periphery of the stator so as to penetrate in the longitudinal direction.

Effect: With the above-described configuration, the stator is directly cooled by the cooling medium flowing through the flow holes.

Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a longitudinal sectional view of a main shaft motor 21 according to the present invention, and FIG. 2 shows a longitudinal sectional side view of the main parts thereof.

The rotor 22 of the main shaft motor 21 is integrated with the main shaft 24,
The main shaft 24 is supported by a front housing 26 and a rear housing 27 of a main shaft head 25 via bearings 28 and 29, which is the same structure as the conventional main shaft motor 1 shown in FIG.

On the other hand, the stator 23 of the main shaft motor 2 is attached to the mounting flange 3.
0.31 to the front housing 26 and rear housing 27 of the spindle head 25. As shown in FIG. 2, the stator 23 is provided with cooling medium circulation holes 32 extending longitudinally through the four corners of the outer periphery. Intake port 33
and an annular passage 35 provided in the rear housing 27 through a through hole 34 provided in the other mounting flange 31.
The annular passage 35 is connected to an intake port 37 of a fan 36 attached to the upper part of the rear housing 27.

Therefore, the air taken in from the air intake port 33 flows through the circulation hole 3.
After cooling the stator 23 directly through the through hole 34
The air is guided through the annular passage 35 and discharged from the exhaust port (not shown) of the fan 36.

Note that if the main shaft motor 21 is large and generates a large amount of heat, it can be effectively cooled by passing a cooling liquid through the circulation hole 32 .

As described in detail, according to the present invention, the stator of the spindle motor is directly fixed to the housing of the spindle head.
The spindle head cylinder 10 and cylinder 11 of the conventional structure are no longer required,
The number of parts and assembly man-hours are reduced accordingly, and weight and compactness can be achieved.

Furthermore, since the stator is directly cooled by flowing air or liquid through the circulation holes provided in the stator, the cooling efficiency is high, and the stator can be sufficiently cooled even with air cooling.

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of the main shaft motor 21 according to the present invention, and FIG.
FIG. 2 is a longitudinal sectional view taken along the line 1-1 in the figure, a longitudinal sectional side view of the same essential parts, and a longitudinal sectional view showing a third conventional structure. 21... Main shaft motor 22... Rotor 23...
Stator 24...Spindle 25...Spindle head
26... Front housing 27... Rear housing 28.29... Bearing 30.31... Mounting flange 32... Distribution hole 33... Air intake port 34.
...Through hole 35...Annular passage 36...Fan

Claims (2)

[Claims] (1) A spindle motor built into the spindle head of a machine tool, characterized in that a stator is directly fixed to the housing of the spindle head, and cooling medium circulation holes are provided in the outer periphery of the stator. Main shaft motor. (2) The main shaft motor according to claim 1, wherein the communication holes are provided at four corners of the outer circumference of the stator so as to penetrate in the longitudinal direction.