JP2001062670A - Built-in type spindle unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform comparatively simple manufacture and cooling of a casing simultaneously with prevention of the occurrence of a twist of a easing due to thermal deformation. SOLUTION: This spindle unit is formed such that a plurality of linear passages 30a, 30e... for cooling extending paralleling the axis of the motor 20 for driving a spindle situated at a spindle 10 are situated on a casing 22 for a motor 20 for driving a spindle, situated on a spindle 10, at intervals along the periphery of the casing 22. A helical groove 31 is formed in the inner surface of each of the passages 30a, 30e... for cooling to improve cooling efficiency. A cooling medium is fed in the passages for cooling from a cooling medium feed part 37 to cool the casing 22 and a stator 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a built-in type spindle unit used for a machine tool or the like, and more particularly to cooling a casing of a spindle driving motor.

[0002]

2. Description of the Related Art FIGS. 5 and 6 show a conventional built-in type spindle unit of this type, in which 10 is a spindle and 11 is a spindle unit main body. The spindle 10 is rotatably attached to the spindle unit main body 11 by bearings 12 and 13 on the front end side and bearings (not shown) on the rear end side. 20
Is a motor for driving the spindle, and the spindle 10
, A casing 22 fitted and fixed to the spindle unit main body 11, and a stator 23 attached to the casing 22.

As shown in FIG. 6, a spiral groove 24 is provided on the outer peripheral surface of the stator 23, and a spiral cooling passage 25 is formed between the stator 23 and the spindle unit main body 11. A cooling medium such as water or oil for cooling is supplied to the left end of the cooling passage 25 in FIG. 5 from an inlet 26 provided in the spindle unit main body 11, and provided to the spindle unit main body 11 through the cooling passage 25. The casing 2 is discharged from the
2 to prevent the temperature of the stator 23 from rising.

The spindle 10 is also provided with a cooling passage (not shown) to prevent the temperature of the rotor 21 from rising, but this is not shown or described.

[0005]

As described above, in the system in which the spiral cooling passage 25 is provided in the casing 22, thermal deformation of the casing 22 occurs along the spiral cooling passage 25, and the casing 22 is twisted. And adversely affect the output of the motor 20 and the positioning accuracy.

[0006] Recently, with the increase in speed and output of the spindle 10, the amount of heat generated by the motor 20 has increased, and an improvement in cooling capacity has been demanded. To improve the cooling capacity,
Although it is effective to increase the flow rate of the cooling medium, it increases the size and cost of peripheral devices such as a pump. In order to improve the cooling capacity without increasing the flow rate, it is effective to increase the surface area of the groove 24 forming the cooling passage 25. To increase the surface area of the spiral groove 24, the groove 24
The pitch should be finer as well as the width of the
There is a limit to secure the flow rate, and the number of processing steps also increases.

The present invention provides a built-in type spindle unit which can be manufactured relatively easily and can effectively cool the casing while eliminating the above-mentioned twisting caused by the thermal deformation of the casing. It is intended to be.

[0008]

According to the present invention, there is provided a built-in spindle unit used for a machine tool or the like, wherein the spindle unit is provided on a casing of a spindle driving motor provided on the spindle. A plurality of cooling passages extending in parallel with the axis of the motor and arranged at intervals along the circumference of the casing, and having a spiral groove on the inner surface; A cooling medium supply unit connected to at least one end of at least one of the plurality of cooling passages;
And a cooling medium discharge portion connected to one end side.

According to the present invention, since the cooling passage extends parallel to the axis of the motor, twisting due to thermal deformation does not occur. In addition, since this cooling passage is a straight shape having a spiral groove on the inner surface, it can be easily manufactured by general processing such as screw hole processing, and the spiral groove provided on the inner surface can be used. The cooling efficiency can be greatly increased.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS. The same parts as those shown in FIGS. 5 and 6 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, a casing 22 includes
As shown in a partially enlarged manner in FIG.
1, linear cooling passages 30 a to 30 h (see FIGS. 3 and 4) extend in parallel with the axis of the motor 20, that is, the axis of the spindle 10, as shown in FIG. It is provided through the other end. The spiral groove 31 may be provided at the same pitch over the entire length from one end to the other end of the cooling passages 30a to 30h,
In order to enhance the cooling effect of the portion corresponding to the stator 23,
The pitch of this portion may be reduced, or the groove 31 may be provided only in this portion. Cooling passages 30a-30h
Are arranged at regular intervals along the circumference of the casing 22, as shown in FIGS.

A front cover 32 and a back cover 33 are attached to both ends of the casing 22. As shown in FIG. 3, the front lid 32 is provided with the cooling passage 30a located at the uppermost position in FIG.
And the cooling passage 3 located to the left of the inlet 34
It has an outlet 35 leading to 0h. A cooling medium supply unit 37 is connected to the inflow port 34, and a cooling medium discharge unit 38 is connected to the outflow port 35.

On the other hand, as shown in FIG. 4, the back cover 33 has a connection passage 36a connecting the cooling passage 30a leading to the inlet 34 and the cooling passage 30b adjacent thereto.
It has a connecting path 36g for connecting the cooling passage 30h communicating with the outlet 35 with the cooling passage 30g adjacent thereto, and a connection for connecting the cooling passages 30c and 30d and the cooling passages 30e and 30f, respectively. Roads 36c, 36
e.

The front lid 32 includes the inlet 34 and the outlet 35.
In addition, there are connecting paths 36b, 36d, 36f for connecting the cooling paths 30b and 30c, the cooling paths 30d and 30e, and the cooling paths 30f and 30g, respectively.

Next, the operation of the present apparatus will be described. When the motor 20 is operated to rotate the spindle 10,
The rotor 21 and the stator 23 generate heat. The rotor 21
The cooling is performed by flowing a cooling medium through a cooling passage (not shown) provided in the spindle 10. On the other hand, the stator 2
3 is cooled by the cooling medium supplied from the cooling medium supply unit 37 to the inflow port 34 as described later.

That is, the cooling medium supplied to the cooling medium inlet 34 flows through the cooling passage 30a, reaches the connection passage 36a of the back cover 33, flows into the adjacent cooling passage 30b, and flows through the cooling passage 30b. It reaches the connection path 36b of the front lid 32, flows into the adjacent cooling path 30c, and connects to the connection path 36c of the back lid 33.
Leads to. Similarly, the cooling medium is supplied to the cooling passage 30.
It flows through d, 30e, 30f, 30g, and 30h, and reaches the cooling medium discharge part 38 from the outlet 35.

The cooling medium is supplied to each of the cooling passages 30a to 30h.
During the cooling, the casing 22 is cooled, and the stator 23 attached to the casing 22 is cooled. At this time, since the spiral grooves 31 are provided on the inner surfaces of the cooling passages 30a to 30h, heat exchange is performed efficiently and the stator 23 is effectively cooled. Further, since the cooling passages 30a to 30h are provided in parallel with the axis of the motor 20, that is, in the longitudinal direction of the casing 22, even if the casing 22 undergoes thermal deformation, the thermal deformation will not occur.
The direction is along the zero axis, and no twisting occurs.
Therefore, the stator 23 attached to the casing 22 is not twisted and does not adversely affect the output of the motor 20, the positioning accuracy, and the like.

In the above-described embodiment, an example is shown in which eight cooling passages 30a to 30h are provided. However, the number thereof can be set as appropriate.
Although an example in which one cooling passage 30a to 30h is sequentially connected to form one passage is shown, two or more passages may be formed in parallel. Furthermore, in the above-described embodiment, an example has been described in which the cooling medium is supplied from the cooling medium supply unit 37 and is discharged to the cooling medium discharge unit 38, but the cooling medium discharge unit 38 is connected to the cooling medium supply unit 37. The cooling medium may be circulated to perform various modifications.

[0019]

As described above, according to the present invention, the casing of the built-in type spindle unit is not twisted by thermal deformation, and the cooling passage is a straight passage having a spiral groove on the inner surface. Therefore, it is possible to obtain an effect that it can be manufactured relatively easily and at the same time can be cooled effectively.

[Brief description of the drawings]

FIG. 1 is a partially omitted schematic cross-sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion Z in FIG.

FIG. 3 is a cross-sectional view of the motor taken along line AA in FIG. 1;

FIG. 4 is a transverse sectional view of the motor taken along line BB in FIG. 1;

FIG. 5 is a partially omitted schematic sectional view showing a conventional built-in type spindle unit.

FIG. 6 is a side view of the casing shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Spindle 11 Spindle unit main body 20 Motor 21 Rotor 22 Casing 23 Stator 30a-30h Cooling passage 31 Spiral groove 32 Front lid 33 Back lid 34 Inlet 35 Outlet 36a-36g Connection path 37 Cooling medium supply part 38 Cooling medium Discharge section

Claims (1)

[Claims] 1. A built-in spindle unit used for a machine tool or the like, wherein the spindle unit is provided on a casing of a motor for driving a spindle provided on a spindle, extends in parallel with an axis of the motor, and extends along a circumference of the casing. A plurality of cooling passages arranged at intervals and having a spiral groove on the inner surface; a cooling medium supply unit connected to one end of at least one of the plurality of cooling passages; A built-in spindle unit, comprising: a cooling medium discharge portion connected to one end of at least one of the plurality of cooling passages.