JPH08312657A - Spindle bearing cooling system - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a bearing cooling and lubricating device for a main shaft, which has two functions of directly cooling the outer ring of the bearing and lubricating and cooling the rollers and balls of the bearing. [Structure] A spindle 1 supported by a plurality of bearings 3 and 4 is rotatably provided in a housing 2, and a cooling jacket is provided in a wall surface of the housing to inject a cooling lubricating liquid into the housing to cool the housing. Then, annular grooves 2C and 2E of the jacket are provided on the inner peripheral side of the housing 2 which supports the bearings 3 and 4 of the main shaft. The annular groove is brought into contact with the outer rings 3A, 4A of the bearings 3, 4, and the outer ring portion of the bearing, which is in contact with the annular groove of the housing, has pores 3B, which are in contact with balls inside the outer ring of the bearing or rollers 3C, 4C.
4B is a bearing cooling device for the main shaft 1 having one or a plurality of shafts 4B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling / lubricating device for a bearing of a machine tool, and more particularly to a cooling / lubricating device capable of cooling and lubricating the bearing portion by simple means.

[0002]

2. Description of the Related Art Conventionally, a cooling device for a spindle and bearings of a machine tool is constructed as shown in FIG. 4, for example. The main shaft 1 is rotatably provided in a housing 4 supported by a plurality of bearings 2 and 3. To cool the main shaft 1 and the bearings 2 and 3, a jacket 5 having a spiral groove 5A is attached to the outer periphery of the housing 4 in an airtight manner, and a cooling liquid C is injected into the spiral groove 5A of the jacket 5 from a pipe 6 to 4 and the bearings 2 and 3 are cooled.

[0003]

However, in the cooling device for the main shaft and bearings, the cooling effect of the main shaft housing 4 and the bearings 2 and 3 is not sufficiently exerted. That is, all of the cooling liquid C is used only for directly cooling the housing 4, and is the cooling centering around the outer peripheral skin portion of the housing 4, so that the cooling of the important bearings 2 and 3 located far from this is performed. The effect is hardly exerted. Further, the effect of lubrication and cooling of the bearings 2 and 3 on the rollers and balls cannot be expected.

In view of the problems of the above-described conventional cooling devices for the main shaft and bearings, the present invention provides bearing cooling having two functions of directly cooling the outer ring of the bearing and lubricating and cooling the rollers and balls of the bearing. An object is to provide a lubricating device.

[0005]

In order to achieve the above object, the present invention provides a main shaft supported by a plurality of bearings rotatably in a housing, and a cooling jacket is provided in a wall surface of the housing. In order to cool the housing by injecting a cooling lubricant into it, an annular groove of the jacket is provided on the inner peripheral side of the housing that supports the bearing of the main shaft, and this annular groove contacts the outer ring of the bearing,
Further, in the bearing outer ring portion of the bearing which is in contact with the annular groove of the housing, one or a plurality of pores which are in contact with balls or rollers inside the outer ring of the bearing are opened, and the bearing cooling device for the main shaft is provided.

[0006]

According to the first aspect of the present invention, since the annular groove is provided on the inner peripheral side of the housing for supporting the bearing of the main shaft and is in contact with the outer ring of the bearing, when the cooling lubricating liquid is supplied to the annular groove of the housing, The outer ring of the bearing is directly and efficiently cooled. Further, in the outer ring portion of the bearing which is in contact with the annular groove of the housing, one or a plurality of pores are formed which are in contact with the balls or rollers inside the outer ring of the bearing. It is supplied to the inner balls or rollers to perform this lubricating action and cooling action.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below. FIG. 1 is a vertical cross-sectional view showing an entire bearing cooling device for a spindle in a machine tool according to the present invention, and FIGS. 2 and 3 are cross-sectional views of a main part according to the present invention. FIG. 4 is a sectional view showing a conventional bearing cooling device.

First, in FIG. 1, the main shaft 1 is fitted and supported on the inner hole wall 2X of the housing 2 at its tip end side by two bearings (bearings) 3 and 4, and the rear end side is also not shown. It is supported by bearings. Further, although not shown, the main shaft 1 is fitted with a rotor of a built-in motor in the middle abdomen thereof, and a multi-layer disc spring and a drawing bar 7 are installed in the inner peripheral hole 1A opened at the axial center position.
The collet 6 strongly pulls in the pull stat 5 of the tool H1 inserted into the tapered hole 1B at the tip of the spindle and fits it. An unclamping device is provided at the rear end of the drawing bar 2, and when the drawing bar 2 is advanced to the drawing bar side, the drawing bar is strongly pushed out to perform the unclamping operation.

A cooling lubricant O for cooling the outer rings of the bearings 3 and 4 and cooling the inner circumference of the housing 2 is supplied to the housing 2 through a through hole 11 opened at the tail end. The through hole 11 has a forward path and a return path 11 ′ extending in the longitudinal direction of the main shaft 1, and a spacer 9 is interposed between the two bearings 3 and 4 supporting the tip end side of the main shaft 1. A spiral groove CG is provided in the inner peripheral hole 2A of the housing which faces the spacer 9 on the outer peripheral side, and the spiral groove CG faces the spacer 9. The spiral groove CG is connected by connecting paths 11A and 11B that connect the outward and return paths of the through holes 11 and 11 '. Further, annular grooves 2C, 2E or spiral grooves are provided in the inner peripheral hole 2A of the housing that fits with the outer rings 3A, 4A of the bearings 3, 4, and these are connected to the annular grooves 2C, 2E by the communication holes 2B, 2D. Has been. Further, in the return hole 11 ', which is the return path, the annular grooves 2C, 2E are formed by the communication holes 2F, 2G.
Is connected to

The details of the outer rings 3A and 4A of the bearings 3 and 4 and the annular grooves 2C and 2E of the inner peripheral hole 2A of the housing, which are fitted, are as shown in FIGS. 1, 2 and 3. In particular, in the outer ring 3A, 4A portion of the bearing 3, 4 in contact with the annular groove 2C, 2E of the housing 2, the pores 3B, 4B in contact with the balls or rollers 3C, 4C inside the outer ring of the bearing.
One to more than one is open. Thereby, the annular groove 2
Only a part of the cooling lubricant O fed into C, 2E passes through the pores 3B, 4B and balls or rollers 3C, 4C inside the outer ring.
It has a relational structure that is supplied so as to leak into.

The bearing cooling device for the main shaft according to the present invention is constructed as described above and operates as follows. First, a cooling lubricant O for cooling the outer rings of the bearings 3 and 4, cooling the inner circumference of the housing 2 and further lubricating and cooling the rollers and balls of the bearings is supplied from a through hole 11 opened at the tail end of the housing 2. To be done. The partially cooled lubricating liquid O is used to cool the outer rings 3A, 4A of the bearings 3, 4 from the communication holes 2B, 2D connected to the through hole 11 to the annular groove 2.
C, 2E, and the annular grooves 2C, 2E face the outer rings of the bearings 3, 4. As a result, the cooling lubricant C
Cools the outer rings 3A, 4A of the bearings 3, 4. The cooled lubricating liquid C is discharged from the communication holes 2F and 2G to the return path 11 'and discharged to the outside.

At this time, a part of the cooling lubricating liquid C in the annular grooves 2C and 2E is a fine hole 3 opened in the outer rings of the bearings 3 and 4.
It is supplied so as to leak to the balls or rollers 3C and 4C inside the outer ring through B and 4B. As a result, an appropriate amount of the cooling lubricating liquid C is applied to the balls or rollers 3C and 4C on the inner side of the outer ring, and the lubricating action and the cooling action are smoothly performed.

For cooling the inner circumference of the housing 2, the cooling lubricating liquid O is supplied from the through hole 11 of the housing 2. Most of the cooling liquid O is connected to the spiral groove CG through the connecting passage 11 in order to cool the bearing spacer 9 and the inner space of the housing.
Sent from A. As a result, the cooling lubricating liquid O cools the spacer 9 of the bearing and the inner peripheral space of the housing while swirling in the spiral groove CG, and is finally sent out from the communication path 11B to the return path 11 '.

The present invention is not limited to the above-mentioned embodiment, and the design of the essential structure can be changed. For example, the number of the bearings 2 is not limited, and the bearings may be provided with cooling means only on the outer ring of the bearings.

[0015]

According to the present invention, since the annular groove is provided on the inner peripheral side of the housing that supports the bearing of the main shaft and is in contact with the outer ring of the bearing, when the cooling lubricating liquid is supplied to the annular groove of the housing, the outer ring of the bearing is formed. It has the effect of being directly and efficiently cooled. Further, in the outer ring portion of the bearing which is in contact with the annular groove of the housing, one or a plurality of pores are formed which are in contact with the balls or rollers inside the outer ring of the bearing, so that only a part of the cooling lubricant is passed from the pores to the outer ring. It is supplied to the balls or rollers on the inner side and has the effect of performing this lubricating action and cooling action.

[Brief description of drawings]

FIG. 1 is a sectional view showing an entire bearing cooling device for a spindle in a machine tool according to the present invention.

FIG. 2 is a sectional view of a main part according to the present invention.

FIG. 3 is a sectional view of a main part according to the present invention.

FIG. 4 is a cross-sectional view showing a conventional bearing cooling device.

[Explanation of symbols]

 1 main shaft 2 housing 2X inner hole wall 2B, 2D, 2F, 2G communication hole 2C, 2E annular groove CG spiral groove O cooling lubricant 3,4 bearing 3A, 4A outer ring 3B, 4B pore 7 drawing bar 9 spacer 11 passage (Outward route) 11 'Passage (Return route) 11A, 11B Connecting route

Claims (1)

[Claims] 1. A spindle in which a spindle supported by a plurality of bearings is rotatably provided in a housing, and a cooling jacket is provided in a wall surface of the housing to inject a cooling lubricant into the housing to cool the housing. An annular groove of the jacket is provided on the inner peripheral side of the housing that supports the bearing, the annular groove contacts the outer ring of the bearing, and the outer ring portion of the bearing that is in contact with the annular groove of the housing has a ball or roller inside the outer ring of the bearing. A bearing cooling device for a main shaft, wherein one or a plurality of pores contacting each other are opened.