JPH11153145A - Bearing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing unit capable of positively discharging excessive lubricating oil to the outside of a housing without positioning all outer ring spacers on the housing. SOLUTION: A housing 11 is provided with a lubricating oil supply passage 12. Outer ring spacers 30 are provided with lubricating oil supply holes 31 communicated with the lubricating oil supply passage 12 and nozzles 32 communicated with the lubricating oil supply holes 31 and discharging lubricating oil toward rolling elements 23. The housing 11 and the outer ring spacers 30 are provided with lubricating oil exhaust passages 13, 34. In addition, a first positioning means is provided to position the outer ring 21 of each radial bearing 20 on each adjacent outer ring spacer 30; and a second positioning means is provided to position each outer ring spacer 30 on the housing 11. Thereby, the lubricating oil supply circuit 12 communicates with the lubricating oil supply holes 31 and the lubricating oil discharging passage 13 communicates with the lubricating oil discharging passage 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing unit for rotatably supporting a rotary shaft used for a bearing of a main shaft of a machine tool.

[0002]

2. Description of the Related Art Bearings used for machine tool spindles, etc.
As a method of lubricating a bearing that supports a rotating shaft that rotates at high speed, a lubrication method using an air flow, such as oil mist lubrication and oil-air mixed lubrication, has conventionally been adopted.

FIGS. 6 and 7 show a conventional example of a main shaft bearing device (bearing unit) of a machining center using oil mist lubrication. FIG. 6 is a sectional view showing a spindle head portion of the machining center. In the figure, 101 is a spindle, 102 is a tool attached to the front end of the spindle 101, 103 and 10
Reference numeral 4 denotes a draw bar and a collet chuck for fastening the tool 102 to the main shaft 101. Since these are well-known configurations, detailed description thereof is omitted.

[0004] As shown in the figure, this bearing device rotatably supports a main shaft 101 around an axis by an angular ball bearing 105. The angular ball bearing 105 includes an outer ring 106 and an inner ring 107 which are race rings, and the outer ring 106
Rolling element 10 rotatably provided between the inner ring 107 and the inner ring 107
And two angular ball bearings 105 are fitted into the housing 111 at appropriate intervals. The position of the outer race 106 is regulated by an outer race spacer 109, and the position of the inner race 107 is regulated by an inner race spacer 110.

[0005] Reference numerals 117 denote annular nozzles provided at both ends of the outer ring spacer 109, which have discharge ports 118 for discharging oil mist toward the rolling elements 108. 1
Reference numeral 14 denotes an oil mist supply path formed in the housing 111, and mist-like lubricating oil (hereinafter, referred to as “oil mist”) is supplied into the oil mist supply path 114 from the outside. Reference numerals 116 denote annular ring grooves provided at both ends of the outer peripheral surface of the outer ring spacer 109, and communicate with the oil mist supply passage 114 provided in the housing 111. Reference numeral 115 denotes an oil mist supply hole provided in the outer ring spacer 109 and the annular nozzle 117, and connects the discharge port 118 and the oil mist supply passage 114 via a ring groove 116. FIG. 7 is a front view showing the outer ring spacer 109 and the annular nozzle 117 as viewed from the direction of arrow E in FIG. 6. As shown in FIG. 7, two sets of oil mist supply holes 115 and discharge ports are provided. 118
Are provided so as to be 180 ° symmetrical.

Reference numeral 120 denotes an oil mist discharge passage formed in the housing 111, and communicates with the outside of the bearing device. Reference numeral 119 denotes oil mist discharge grooves formed on both end surfaces of the outer ring spacer 109. The oil mist discharge grooves 119 communicate the internal space of the angular ball bearing 105 with the oil mist discharge passage 120.
The outer ring spacer 109 is provided with a positioning hole 122, and the positioning pin 12 provided in the housing 111 is provided.
1 and the positioning holes 122 are engaged with each other, so that the oil mist discharge passage 120 and the oil mist discharge grooves 11 are formed.
9 are positioned so that they communicate with each other.

Reference numeral 112 denotes a front cover that covers the front end of the spindle 101, and reference numeral 113 denotes an outer peripheral cover that covers the outer peripheral portion of the housing 111.

According to this bearing device, oil mist is supplied into the oil mist supply passage 114 from outside the device, and is discharged from the discharge port 118 through the ring groove 116 and the oil mist supply hole 115 in order. Is done. The discharged mist-like lubricating oil adheres to each part of the angular ball bearing 105 to form an oil film and lubricate the oil film.

On the other hand, a part of the oil mist discharged into the angular ball bearing 105 is
9. The oil is discharged to the outside of the bearing device via the oil mist discharge path 120 in order. Since not all of the oil mist supplied into the angular ball bearing 105 is used for lubricating action, it is necessary to supply an amount more than that required for lubrication itself in order to perform sufficient lubrication. However, if the excess oil mist that is not used for lubrication is not discharged out of the system, the excess oil mist accumulates in the housing 111, and this is stirred by the rolling elements 108 and the like to generate stirring heat, and the entire spindle head rises in temperature. Problem arises. Therefore, as described above, the excess oil mist is discharged out of the housing 111.

[0010]

By the way, in the field of machine tools in recent years, in order to perform micromachining such as manufacturing a micromachine by machining, or to increase machining efficiency, a spindle which rotates at a higher speed than ever before. There is a demand for a bearing that can stably support such a high-speed rotating main shaft.

Generally, it is considered that a main shaft of a machine tool that rotates at high speed should be thick and short. Therefore, in order to rotate the main shaft at a high speed in response to the above demands, the main shaft itself needs to be thick and short, and accordingly, the bearing device for supporting the main shaft also needs to be thick and short. Further, in order to stably support the main shaft rotating at high speed, it is necessary to support the main shaft with a large number of bearings.

However, in the above-described conventional bearing device, the axial length thereof is reduced, that is, the length of the housing 111 is reduced, and a large number of angular ball bearings 105 and outer ring spacers 109 are provided in the housing 111. If the inner ring spacer 110 is housed, the positioning pin 121 may be attached to the housing 11 depending on the space.
As a result, all the outer ring spacers 109 cannot be accurately positioned with respect to the housing 111, and as a result, the mutual positional relationship between the oil mist discharge passage 120 and the oil mist discharge groove 119 is determined. Cannot be performed, and a situation in which the two cannot be communicated may occur. In this case, there is a problem that the excess oil mist accumulates in the housing 111 and the temperature of the spindle head rises due to stirring heat generated by the stirring, which is extremely inconvenient.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a bearing capable of reliably discharging surplus lubricating oil out of the housing without positioning all outer ring spacers with respect to the housing. The purpose is to provide units.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a radial bearing including an outer ring and an inner ring as race rings and a rolling element, and houses three or more of the radial bearings. A bearing unit provided with a housing to be mounted and an outer ring spacer and an inner ring spacer disposed between the radial bearings, wherein a lubricating oil supply path is provided in the housing, and a lubricating oil supply communicating with the lubricating oil supply path is provided. In the bearing unit, a nozzle communicating with the hole and the lubricating oil supply hole and discharging the lubricating oil toward the rolling element is provided in the outer ring spacer, and a lubricating oil discharge path is provided in the housing and the outer ring spacer. First positioning means for positioning between the outer ring of each radial bearing and the outer ring spacer adjacent thereto, and positioning between at least one of the outer ring spacers and the housing. A second positioning means is provided, said first
And the second positioning means allows the lubricating oil supply passage of the housing to communicate with the lubricating oil supply hole of each of the outer race spacers, and the lubricating oil discharge passages of the housing and the outer race spacers to each other. Are made to communicate with each other.

According to the present invention having the above configuration, the first positioning means positions the outer ring of each radial bearing and the outer ring spacer adjacent thereto, and the respective outer rings via the outer ring. The positional relationship between the spacers is determined, and the relative positions of the lubricating oil supply holes and the lubricating oil discharge passages provided in the respective outer ring spacers in the circumferential direction are the same for the respective outer ring spacers. Is positioned.

By positioning the at least one outer race spacer and the housing by the second positioning means, the positional relationship between all outer race spacers and the housing is determined. And the lubricating oil supply holes provided in the outer ring spacers are connected to each other, and the housing and the lubricating oil discharge passages provided in the outer ring spacers are connected to each other.

As described above, according to the present invention, by positioning the relative positions of the respective outer ring spacers via the outer ring of the radial bearing, and by positioning between at least one outer ring spacer and the housing. Since the positional relationship with the housing can be determined for all the outer ring spacers, even if all the outer ring spacers cannot be individually positioned with respect to the housing due to space problems, it is easy and easy. All outer ring spacers can be reliably positioned with respect to the housing.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing a spindle head of a lathe using the bearing unit according to the present embodiment, and FIG. 2 is a cross-sectional view in the direction of arrows AA. FIG. 1 is also a cross-sectional view in the direction of arrows BB in FIG.

As shown in FIG. 1, the spindle head includes a spindle 2, a bearing unit 10 for supporting the spindle 2, and a headstock 1 for supporting the bearing unit 10. In the drawing, reference numeral 3 denotes a front cover, 4 denotes a front cover lid, 5 and 6 denote front collars, and 7 denotes a rear collar, which prevent dust and the like from entering the bearing unit 10. Reference numeral 8 denotes a bearing nut.

As shown in FIG. 1, the bearing unit 10
Is a housing 11 supported by the headstock 1, a plurality (four in this example) of angular ball bearings 20 housed in the housing 11, outer ring spacers 30 provided between the angular ball bearings 20, and A first positioning means 40 (shown in FIG. 3) and a first positioning means 40 for positioning a positional relationship between the inner ring spacer 35, the nozzle 32 provided in each outer ring spacer 30, and the housing 11 and the outer ring spacer 30. 2 positioning means 45 (shown in FIG. 4). Hereinafter, details of each unit will be described.

The angular ball bearing 20 includes an outer ring 21 and an inner ring 22 serving as race rings, a rolling element 23 rotatably provided between the outer ring 21 and the inner ring 22, and a rolling element 23.
Is a known bearing comprising a retainer 24 for holding the bearing.

The outer race spacer 30 and the inner race spacer 35 are both members having a ring shape. The angular ball bearing in which the pair of outer race spacers 30 and the inner race spacer 35 are juxtaposed in the housing 11 is provided. It is arranged in each of 20 spaces. The distance between the outer rings 21 in the axial direction of the angular ball bearing 20 is kept constant by the outer ring spacer 30, and the distance between the inner rings 22 is also kept constant by the inner ring spacer 35.

On the side surface of the outer race spacer 30, the nozzle 32 having a discharge port 33 toward the angular ball bearing 20 is detachably provided by screwing.
Is provided with an oil mist supply hole 31 communicating with the discharge port 33. As shown in the drawing, the outer race spacer 3 located in the middle of the three
No. 0, nozzles 32 are provided on both side surfaces thereof, and as shown in FIG. 2, the nozzle 32 and the oil mist supply hole 31 are provided at 180 ° symmetrical positions in the circumferential direction of the outer ring spacer 30. I have. 1 and 2
As shown in FIG. 5, a cutout oil mist discharge passage 34 is provided at an outer peripheral portion of each outer ring spacer 30 at a position where the nozzle 32 and the oil mist supply hole 31 form an appropriate angle.

As shown in FIG. 1, the housing 11 has a housing hole 14, in which the angular ball bearing 20, the outer ring spacer 30, and the inner ring spacer 35 are provided.
Is stored. Also, as shown in FIGS. 1 and 2,
The housing 11 is provided with an oil mist supply passage 12 and an oil mist discharge passage 13 which are opened at predetermined positions on the inner peripheral surface of the storage hole 14, and each oil mist supply hole 31 of the outer race spacer 30 and the oil mist supply passage 31 are provided. Oil mist supply path 12
Are communicated with each other, and the oil mist discharge passages 34 and the oil mist discharge passages 13 are communicated with each other. The oil mist supply path 12 is connected to an external oil mist supply source (not shown), and the oil mist is supplied into the oil mist supply path 12 from this oil mist supply source (not shown). It has become. On the other hand, the oil mist discharge passage 13 communicates with the outside of the system (outside the bearing unit 10), so that excess oil mist in the housing 11 is discharged to the outside of the system via the oil mist discharge passage 13. Has become.

FIG. 3 is a sectional view taken in the direction of arrows DD in FIG. 2. As shown in FIG. 3, positioning holes, which are blind holes, are formed on both side surfaces of each outer ring 21 of the angular ball bearing 20. The outer ring spacer 30 is provided with a positioning hole 41 penetrating on both side surfaces thereof. Then, the positioning pins 43 are inserted into the positioning holes 41 and the positioning holes 42, and the respective outer race spacers 30 provided between the outer races 21 and the respective outer races 21 are engaged with each other, whereby each outer race is engaged. 2
1, the positions of the oil mist discharge passage 34, the oil mist supply hole 31 and the nozzle 32 in the circumferential direction of each outer ring spacer 30 coincide with each other.
Thus, the positioning holes 41 and 42 and the positioning pin 4
3 constitutes the first positioning means 40.

FIG. 4 is a cross-sectional view in the direction of arrows CC in FIG. 2. As shown in FIG. 4, the outer ring spacer 30 located in the middle of the three outer ring spacers 30 arranged side by side. A positioning hole 47 is provided on the outer peripheral surface of the housing 30, and a positioning hole 46 penetrating toward the inner peripheral surface is provided on the housing 11. The positioning pin 48 is inserted into the positioning holes 46 and 47 and the housing 11 and the outer ring spacer 30 are engaged with each other, so that the positioning operation of the first positioning means 40 is performed. Together with the outer ring spacer 30 and the housing 1
1 is positioned in the circumferential direction, whereby the oil mist supply passage 12 and the oil mist supply hole 3 are positioned.
1 and the oil mist discharge path 13 and the oil mist discharge path 34 are connected. Thus, the positioning holes 46, 47 and the positioning pin 48 constitute the second positioning means 45. The positioning hole 46 is sealed by a plug 49.

According to the bearing unit 10 according to the present embodiment having the above configuration, the four angular ball bearings 2
0, and 3 provided between the angular ball bearings 20
When the pair of outer ring spacers 21 and inner ring spacers 22 are sequentially stored in the storage holes 14 of the housing 11, first, the positioning holes 42 provided in the outer ring 21 of the angular ball bearing 20 and the positions provided in the outer ring spacer 30. Positioning pins 43 on both sides of the hole 41
Are positioned, the mutual positional relationship between each outer ring 21 and the outer ring spacer 30 is determined. Thereby, the outer ring 21
The positions of the outer ring spacers 30 are positioned such that the circumferential positions of the oil mist discharge path 34, the oil mist supply hole 31, and the nozzle 32 coincide with each other at the outer ring spacers 30. Is done.

Next, the stored outer ring 21 and outer ring spacer 3
0 is integrally rotated in the rotational direction, and the positioning hole 47 provided in the outer race spacer 30 located in the middle of the three outer race spacers 30 arranged in parallel and the positioning hole formed in the housing 11 are formed. Positioning pins 48 are fitted into both holes 46. This allows
The positional relationship between the outer ring spacers 30 and the housing 11 in the circumferential direction is determined, the oil mist supply passage 12 and the oil mist supply hole 31 communicate with each other, and the oil mist discharge passage 13 and the oil mist discharge The road 34 is communicated.

As described above, according to the bearing unit 10, the angular positioning of the angular ball bearing 2 is performed by the first positioning means 40.
By positioning the respective outer ring spacers 30 via the outer ring 21 of No. 0 and further positioning the outer ring spacer 30 and the housing 11 at an intermediate position by the second positioning means 45, Each outer ring spacer 30 and housing 1
1 can be positioned in the circumferential direction, so that even if all the outer ring spacers 30 cannot be individually positioned with respect to the housing 11 due to space issues, at least By positioning one outer ring spacer 30 with respect to the housing 11, all the outer ring spacers 30 can be positioned with respect to the housing 11 easily and reliably.

Thus, according to the bearing unit 10 assembled as described above, the oil mist supply source (not shown) passes through the oil mist supply passage 12 and the oil mist supply hole 31 in order, and Mist is supplied and the angular contact ball bearing 20 is discharged from the discharge port 33 of the nozzle 32.
And the angular ball bearing 20 is lubricated. On the other hand, surplus oil mist not used for lubrication is discharged out of the system via the oil mist discharge paths 13 and 34.

Incidentally, in the bearing unit 10 of this embodiment,
Since the nozzle 32 is detachably provided on the side surface of the outer race spacer 30 by screwing, the nozzle 32 can be easily and reliably installed on the side surface of the outer race spacer 30.

Although the embodiment of the present invention has been described in detail above, it is needless to say that the specific embodiment of the present invention is not limited to this. For example, FIG.
As shown in (b) and (c), the nozzles 32 and the oil mist supply holes 31 provided in the outer ring spacer 30 may be provided so that the phases thereof are different for each outer ring spacer 30. In this case, the oil mist supply hole 3 of each outer race spacer 30
The oil mist supply passages 12 are provided at positions corresponding to and corresponding to the phase of 1, and the oil mist supply passages 12 are individually communicated with the oil mist supply holes 31 of the outer ring spacers 30, respectively. Accordingly, oil mist having a uniform pressure can be supplied to each oil mist supply hole 31 without causing pressure loss, and each angular ball bearing 20 can be evenly lubricated.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a spindle head of a lathe using a bearing unit according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view in the direction of arrows AA in FIG.

FIG. 3 is a cross-sectional view in the direction of arrows DD in FIG. 2;

FIG. 4 is a cross-sectional view in the direction of arrows CC in FIG. 2;

FIG. 5 is a front view showing a modified example of the outer ring spacer.

FIG. 6 is a sectional view showing a spindle head portion of a conventional machining center.

FIG. 7 is a front view showing the outer ring spacer and the annular nozzle viewed from the direction of arrow E in FIG. 6;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 headstock 2 spindle 10 bearing unit 11 housing 12 oil mist supply path 13 oil mist discharge path 20 angular ball bearing 21 outer ring 22 inner ring 23 rolling element 30 outer ring spacer 31 oil mist supply hole 32 nozzle 33 discharge hole 34 oil mist discharge path 35 inner ring spacer 40 first positioning means 41 positioning pin 42 positioning hole 43 plug 45 second positioning means 46 positioning hole 47 positioning hole 48 positioning pin

Claims (1)

[Claims] 1. A radial bearing comprising an outer ring and an inner ring as race rings and a rolling element, a housing for accommodating three or more of the radial bearings, and an outer ring spacer and an inner ring disposed between the radial bearings. A lubricating oil supply passage in the housing, a lubricating oil supply hole communicating with the lubricating oil supply passage, and a lubricating oil communicating with the lubricating oil supply hole toward the rolling element. And a bearing unit configured to provide a lubricating oil discharge path in the housing and the outer ring spacer, wherein the outer ring of each of the radial bearings and the outer ring spacer adjacent thereto are provided. A first positioning means for positioning between the outer ring spacers and a second positioning means for positioning between the outer ring spacer and the housing; the first positioning means and the second positioning means; position The lubricating oil supply passage of the housing and the lubricating oil supply hole of each of the outer race spacers are communicated with each other, and the lubricating oil discharge passages of the housing and the outer race spacers are communicated with each other. Features bearing unit.