JPH04343638A - Cooling device of motor for main spindle - Google Patents

Abstract

PURPOSE:To improve the performance of a machine tool by cooling the main spindle of the machine tool employing a built-in motor. CONSTITUTION:The rotor 6 of a motor rotating a main spindle 2 is fitted to the main spindle 2 via a heat insulating member 7. One end side of a heat pipe 8 radiating the heat of the heat insulating member 7 is buried in the heat insulating member 7. The heat from the rotor 6 is not transferred to the main spindle 2, and the temperature of the main spindle 2 can be maintained at a low temperature.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a spindle motor cooling device used for cooling the spindle head, headstock, or feed drive system motor of a machine tool, and is applicable to machine tools such as lathes and machining centers. It is something.

0002

[Prior Art] Conventionally, as a means for driving and rotating a spindle supported by a spindle head or a spindle stock of a machine tool,
A built-in motor is known in which a rotor is fastened to a spindle head or a spindle in a headstock, and a stator is fixed inside the spindle head or the like in opposition to the rotor. Furthermore, various methods for suppressing conduction of heat generated by the motor to the main shaft and main shaft bearing are known and practiced.

[0003] As an example of the method,
A cooling device using this example is shown in FIG. 2, which was published in Japanese Patent No. 103. As shown in FIG. 2, the conventional cooling device for cooling the headstock 21 uses heat insulation with a small coefficient of linear expansion in the part of the main shaft 22 that faces the stator 25 having the coil end 31 and to which the rotor 26 is fastened. Member 27
At the same time, a groove 27a through which the cooling gas 32 flows is formed in the outer periphery of the heat insulating member 27. Then, a hole 33 that penetrates between the groove 27a and the inner peripheral side of the main shaft 22 is formed corresponding to the position of the groove 27a, and the cooling gas 32 is discharged to the outside of the machine through the hole 33. This device adopted a structure that

[0004] As the cooling gas 32, a part of the air flowing between the jet port 30 and the discharge port 29 is used. Further, 23 and 24 are main shaft bearings, and 35 is an oil jacket.

[0005]

[Problems to be Solved by the Invention] In the structure described above, the hole 33 penetrates between the inner diameter side of the spindle and the outer diameter side of the spindle, so taking a lathe among machine tools as an example, the following It has the following disadvantages. That is, in bar machining, a bar with cutting water attached may be passed through the main shaft 22, so the cutting water also enters the main shaft 22, and the cutting water flows through the hole 33 into the stator 25 and the motor that constitute the motor. There was a risk that the particles would flow into the interior of the rotor 26, resulting in damage to the motor.

On the other hand, it is difficult to form and attach a heat insulating member to the outer periphery of the main shaft.

[0007]

[Means for Solving the Problems] A spindle motor cooling device according to the present invention includes a motor that is attached to a spindle of a machine tool and drives and rotates the spindle, and a motor that is interposed between the rotor of the motor and the spindle. A heat insulating member that prevents conduction of heat from the rotor to the main shaft; and a heat pipe that has one end embedded in the insulating member and radiates heat from the insulating member from the other end. be.

[0008]

[Operation] A motor attached to the main shaft of a machine tool drives and rotates the main shaft, and heat is generated from the motor accordingly.

At this time, the heat insulating member prevents heat from being transferred from the rotor of the motor to the main shaft, and furthermore, the heat pipe radiates the heat applied to the heat insulating member.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS A main shaft motor cooling device according to an embodiment of the present invention is shown in FIG. 1, and this embodiment will be explained based on this figure.

FIG. 1 shows a sectional view of the headstock of a lathe, which is a machine tool. As shown in this figure, a main spindle 2 is rotatably supported on a headstock 1 via a front bearing 3 and a rear bearing 4. A rotor 6 of a motor that generates driving rotational force is fastened to the main shaft 2 between the front bearing 3 and the rear bearing 4 so as to be located on the same axis as the main shaft 2. A heat insulating member 7 in the shape of a bush is interposed.

The material of the heat insulating member 7 is, for example, a ceramic material having a small coefficient of linear expansion and a high heat insulating effect, and the rotor 6 and the heat insulating member 7 are fastened together by shrink fit. The heat insulating member 7 and the main shaft 2 are connected to a cylindrical wedge 16.
The rotational motion of the motor can be transmitted to the main shaft 2. In addition, one end side of a plurality of heat pipes 8 is embedded in this heat insulating member 7 in an annular positional relationship centered on the main shaft 2, and the other ends are embedded in the same direction as the axis of the main shaft 2. side end 8
b protrudes from the heat insulating member 7 to radiate heat from the heat insulating member 7.

The stator 5, which has coil ends 11 formed at both ends, is fastened by shrink fit to the inner circumferential side of an oil jacket 15, which has grooves 15a formed on the outer circumferential side through which cooling oil can flow. Further, the stator 5 and the oil jacket 15 are press-fitted into the headstock 1 in a positional relationship on the same axis as the main shaft 2.

On the other hand, intake ports 14 are formed at both ends of the headstock 1 to take in cooling gas 12 such as air from outside into the headstock 1. is configured to be ejected from an ejection port 10 in the headstock 1. Then, the jetted cooling gas 12 is directly sprayed onto the coil end 11 and the end 8b of the heat pipe 8, so that heat can be absorbed from the coil end 11 and the end 8b of the heat pipe 8. Furthermore, a plurality of discharge ports 9 are formed in the headstock 1.
The cooling gas 12 that has absorbed heat can be discharged from the headstock 1. Note that the arrow 17 represents the flow of heat.

Next, the operation of the cooling device according to this embodiment will be explained.

Heat generated by the motor when the spindle 2 rotates is generated from the stator 5, rotor 6, and coil end 11, but the heat of the stator 5 is generated by cooling oil 13 supplied from outside of the headstock 1. It flows between the jacket 15 and the headstock 1, is absorbed, and is discharged to the outside.

On the other hand, the heat generated from the rotor 6 is difficult to be conducted by the heat insulating member 7, and the conduction of heat to the main shaft 2 can be kept low. Furthermore, the heat conducted from the rotor 6 without being completely insulated is absorbed by the heat pipe 8 and flows to the end 8b of the heat pipe 8. Then, by ejecting the cooling gas 12 taken in from outside the headstock 1 to the end 8b of the heat pipe 8, this heat is removed and the exhaust port 9
from the headstock 1 to the outside of the headstock 1.

Furthermore, the heat generated from the coil end 11 of the motor is also absorbed and taken away from the coil end 11 by jetting the same cooling gas 12 supplied from the outside to the coil end 11, and is removed from the exhaust port 9. It is discharged together with the cooling gas 12.

That is, in this embodiment, the main shaft 2 and the rotor 6
A heat insulating member 7 is interposed between the heat pipe 8 and the heat pipe 8 to provide heat insulation, and the heat pipe 8 absorbs heat, and the absorbed heat is discharged to the outside together with the cooling gas 12. and,
By also cooling the stator 5 with oil, the heat generated from the motor is efficiently removed and the headstock 1 is prevented from being overheated.

[0020]

[Effects of the Invention] According to the main shaft motor cooling device of the present invention, a heat insulating member is interposed between the main shaft and the rotor of the motor, and a heat pipe is embedded in the heat insulating member. The heat transfer to the main shaft is reduced, resulting in the following effects. (1) When using a built-in motor to drive the main axis of a machine tool, it is possible to increase the capacity of the motor. (2) Heat transfer from the motor is suppressed, improving the accuracy of thermal displacement of the headstock, spindle head, etc. (3) Heat transfer to the main shaft bearing is suppressed, the life of the bearing is extended, and the rotation speed of the main shaft can be set high. (4) Compared to conventional methods, cooling can be performed more efficiently at lower cost.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a headstock according to an embodiment of the present invention.

FIG. 2 is a sectional view of a headstock according to the prior art.

[Explanation of symbols]

1, 21 Headstock 2, 22 Main shaft 5, 25 Stator 6,26 rotor 7, 27 Insulation member 8 Heat pipe 9, 29 Discharge port 10,30 spout 11, 31 Coil end 12,32 Cooling gas 13 Cooling oil 14 Intake port 15,35 Oil jacket

Claims (1)

[Claims] 1. A motor attached to a main shaft of a machine tool to drive and rotate the main shaft, and a heat insulator interposed between the rotor of the motor and the main shaft to prevent heat conduction from the rotor to the main shaft. 1. A cooling device for a spindle motor, comprising: a member; and a heat pipe having one end embedded in the heat insulating member and radiating heat from the heat insulating member from the other end.