JPS5824700A - Method of lubricating bearing for spindle - Google Patents

Abstract

PURPOSE:To reduce the temperature difference between the inner and outer races of a bearing for a machine tool, by mixing oil mist of room temperature with air of low temperature just upstream to the bearing to prepare oil mist of low temperature and by directly supplying the low-temperature oil mist to the bearing. CONSTITUTION:Oil mist of room temperature is conducted from a supply hole 31 to the lower ends of nozzles 26a, 26b through branch pipes 32a, 32b. Air of low temperature is supplied from air pipes 30a, 30b. The oil mist of room temperature is mixed with the air of low temperature so that the temperature of the oil mist is made low. The oil mist of temperature made low is supplied to front bearings 3a, 3b and rear bearings 4a, 4b through peripheral grooves 11, 14 and the holes 12, 15 of seats 10a, 13a between the outer races of the bearings and then drained through outlet holes 33a, 33b. According to this constitution, the temperature difference between the inner and the outer races of the bearings is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of lubricating a bearing part of a machine tool. 1) Oil mismixed with low-temperature air just before the bearing part is guided to the bearing part to reduce the temperature difference between the inner and outer rings of the bearing. This invention relates to a spindle bearing lubrication method for the purpose of lubrication.

Generally, there are oil mist lubrication, grease lubrication, and other methods for lubricating rolling bearings of machine tool spindles. These lubrication methods have standby measures such as minimizing the amount of lubricating oil supplied to minimize the rise in bearing temperature caused by the large deformation rate that oil undergoes at the rolling contact area of the bearing rolling elements. ing. However, in recent years, the need to keep the bearing temperature rise to a minimum has increased due to increased speeds.

Conventionally, as shown in FIG. 1, a method has been adopted in which the housing around the outer ring of the main shaft is cooled with oil or air.

That is, the spindles 1 and 2 are rotatably supported by the front bearings 3a, 3b, 3c and the rear bearing 4, and the rear part of the spindle 1 receives rotational driving torque from a drive source (not shown). Also,
- Oil groove 5a in the housing 2 that cools the vicinity of the bearing outer ring
, 5b are processed, and temperature-controlled cooling oil is supplied to the inlet 6a.

The structure is such that the oil passes through the oil grooves 5a and 5bi from 6b and is discharged to the lower h and 7b.

Therefore, based on this conventional structure, the lubrication method does not directly cool the bearing, which is the heat generating part, so the bearing gap becomes smaller due to the temperature difference between the inner and outer rings of the bearing, which may cause heat generation. There is sex. For this reason, if the speed of the spindle 1 is to be further increased in the future, it will be necessary to cool the bearing itself.

Furthermore, in grease lubrication, it is difficult to directly cool the bearing rolling elements because it is necessary to seal the grease in the bearing portion.

On the other hand, in oil-filled lubrication, there is a cooling effect due to the air at a constant rate, but while the bearing rolling elements can be cooled by lowering the mist temperature, the lubricating oil in the mist is applied to the pipe wall due to the temperature drop. There are disadvantages such as easy adhesion, and a predetermined amount of lubricating oil may not reach the bearing.

The present invention is based on the conventional structure, and in order to solve the problem, it is an object of the present invention to provide a method for lubricating a spindle bearing, which suppresses the rise of the bearing portion and reduces the temperature difference between the inner and outer rings of the bearing. The gist of this is that a highly chained mist at normal temperature is guided through a spindle, mixed with low-temperature air and room-temperature oil mist just before the bearing, and then the mixed, low-temperature oil mist is directly passed through the spindle. It is characterized by being guided to the bearing part.

Hereinafter, one embodiment of the lubrication method according to the present invention will be described in detail based on FIG.

Nine front bearings 3 are fitted into the spindle 1 and housing 2.
A, 3b and rear bearings 4a+4b support rotation, and the outer ring side spacer 10a is located between the front bearings 3a, 3b.

An inner ring side spacer 101) is provided, and an outer ring side spacer 10aK is provided with an outer circumferential groove l! Holes 2 leading to are bored at several places on the circumference. Similarly, an outer ring spacer 13a and an inner ring spacer 13b are provided between the rear bearings 4a and 4b, and the outer ring spacer 13a has holes 15 communicating with the outer periphery w#14 at several locations on the circumference. It is perforated.

On the other hand, the outer rings of the front bearings 3a and 3b are positioned by caps 17 fitted to the housing 2 with bolts 16, and similarly the outer rings #i and poles of the rear bearings 4a and 4b are fitted to the housing 2 by 18. It is positioned and held by a cap 19. Further, the front bearings 3a, 3b and the ridge bearings 4a, 4b are connected to the shaft nut 20. It is positioned on the spindle 1 by the spacer 21° and the spacer 22, and the two-piece housing frame 23Kf1 is fitted together with the bolt 2.
It is fixed by 4. 7 frame 23 has outer ring side spacers 10' of front bearings 3a, 3b and ridge bearings 4a, 4b.
e Through hole 2 communicating with outer circumferential groove 11.14 of 13a
The nozzles 26a, 26b having 5a, 25bt" are connected to the bolts 28a through the plates 27a, 27bf.
, 28b, and the air supply pipe 3 is connected to the nozzles 26a, 26b via nipples 29a, 29'b.
0a and ao'b are connected.

A supply hole 31 for oil mist of lubricating oil is provided in the center of the frame 23, and the supply hole 31#i passes through branch holes 32a and 32b in the housing 2 to the through holes of the nozzles k26a and 26b. 25a, 25
It communicates with the lower end of b. Furthermore, housings 2 and 7
Oil drain holes 33a and 33b are bored in V-A23, and the outer ring side spacer lQa,
The oil mist supplied through the holes 12.15 of 13a passes through the front bearings 3a, 3b and the rear bearings 4a, 4b, and then is discharged to the outside.

Note that 34 in FIG. 2 is a cover fitted to the front end of the spindle 1 to prevent chips and the like from entering the bearing section. Therefore, in a spindle bearing having such a structure, first of all, When oil mist, which is lubricating oil at room temperature, is supplied from the supply hole 31, the branch holes 32a and 32b
"f: Nozzle 26a, 2 immediately in front of the bearing section
6b, and is mixed with the low-temperature air supplied from the air supply pipe 30a30b, and is distributed as low-temperature oil mist into the outer circumferential grooves 13, 14 and the outer ring side spacer IQa, 13a.
Through the hole 12.15t, oil is supplied into the front bearings 3a, 3b and the rear bearings 4a, 4b, and one bearing 3a, 3b.
The lubricating oil supplied to housing 2 and 4a and 4b is
and oil drain holes 33a, 33 provided in the frame 23.
/b and is discharged to the outside.

The above is shown in the drawings! i! As explained in detail in the embodiments, the spindle bearing lubrication method according to the present invention involves mixing oil mist at room temperature with low-temperature air immediately before the bearing, and supplying the oil mist to the bearing as a low-temperature oil mist. Since the bearing rolling elements are directly cooled, the temperature difference between the inner and outer rings of the bearing can be reduced, and the temperature rise in the bearing can be suppressed.

In addition, since oil mist at room temperature is mixed with low-temperature air in front of the bearing to form a low-temperature oil mist, the drop in temperature lowers the tolerance level of l18W# oil in the oil mist, causing it to adhere to the piping wall and cause the bearing to fall. There is no negative effect caused by insufficient amount of lubricating oil in the pipe, and local deformation caused by low-temperature air in the pipe can also be reduced.

Further, it is possible to obtain an effective lubrication method that reduces the temperature rise of the bearing while taking advantage of the characteristics of the oil mist lubrication system, which minimizes the amount of lubricating oil supplied to the bearing gK to suppress the rise in bearing temperature.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a bearing portion showing a conventional embodiment, and FIG. 2 is a longitudinal sectional view of the bearing portion showing a main part of a lubrication method according to the present invention. In the drawing, the lFi spindle, 2 is a housing, 3a, 3
b#'i front bearing, 4a, 4b are rear bearings, 10a,
13a Fi 外翰弒園ま座、IOb、13b t
1 Inner ring side spacer, 11.14 is outer circumferential groove, 12.15 is hole,
23Fi frame, 26&, 26b nozzle, 30
a. 301) tit air supply pipe, 31 is a supply hole, 33a,
33b is an oil drain hole. Patent applicant Mitsubishi Heavy Industries, Ltd. Sub-agent Patent attorney Shibe Mitsuishi (1 other person)

Claims (1)

[Claims] In the method of lubricating the bearing by supplying oil mist to the bearing, room-temperature oil mist and low-temperature air are mixed just before the bearing, and the mixed, low-temperature oil mist is guided directly to the bearing. A method for lubricating a spindle bearing, characterized in that: