KR20140114822A

KR20140114822A - Rolling bearing assembly with internal lubrication

Info

Publication number: KR20140114822A
Application number: KR1020147018547A
Authority: KR
Inventors: 올리비어 베르베; 프랑크 베렌스; 피에트 루그트
Original assignee: 아크티에볼라게트 에스케이에프
Priority date: 2012-01-23
Filing date: 2012-01-23
Publication date: 2014-09-29
Also published as: EP2807386A1; CN104067010A; JP2015504148A; WO2013110319A1

Abstract

The rolling bearing assembly comprises an inner ring 2, an outer ring 3, at least one row of rolling elements 4 arranged between the inner ring 2 and the lace 13a, 13b provided in the outer ring 3 ) And a circular housing (6), at least one of the rings (3) being arranged in the housing, the ring (3) comprising two half ring portions (3a, 3b), each The half ring portions 3a and 3b have radial portions 10a and 10b and two axial cylindrical portions 9a, 9b, 12a and 12b extending from the radial portions 10a and 10b toward the outer side , One of the two half rings (3a) of the ring (3) forms a closed space (23a) with the circular housing (6), the lubricating oil (25) is arranged in the closed space The one half ring portion 3a includes passage means 24a and 27a for the lubricating oil 25 passing from the closed space 23a to the races 13a and 13b . The rolling bearing assembly 1 includes pressure generating means 26a arranged in the closed space 23a at the side facing the passage means 24a.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a rolling bearing assembly having an internal lubrication function,

The present invention relates to a rolling bearing having an outer ring with rolling elements, in particular an inner ring and rolling elements forming one or more rows, said rolling elements being arranged between the raceways provided in the two rings, is fixed by a cage. For example, the rolling elements are balls. The rolling bearings are, for example, rolling bearings used in industrial electric motors or vehicular transmissions.

In these applications, the bearings are mainly subjected to radial loads. The service life of the rolling bearing is essentially related to the lubrication of the bearing. In general, defects related to lubrication lead to breakage of rolling bearings and rapid degradation of the rolling bearings.

For example, a known deep groove ball bearing defines a chamber with the inner and outer rings, and a lubricant, such as grease, is inserted into the chamber while the bearing is assembled. The bearings are said to be "for life" lubricated. In the long run, however, the aging of the grease and the mixing of the complex grease with the heating cycle experienced by the bearings causes a deterioration of the state of the grease. Periodic re-injection of grease may be considered for rolling bearings of this type. However, the above operation is costly.

To avoid this periodic grease refill operation, a rolling bearing disclosed in FR-A1-2923 277 has an outer ring having an inner ring and at least one row of rolling elements and a circular ring surrounding the outer ring And a housing. Wherein the outer ring is comprised of two separate or half rings, each separate part forming a closed space with the housing, wherein grease or oil is contained within the enclosed space Located. The sealed space acts as a grease or oil reservoir. A passage means for lubricating oil is provided in the two separate portions of the outer ring so that the lubricating oil passes from the enclosed space toward the rolling elements.

The rolling bearing can be operated for a long time by internal lubrication.

However, the movement of the lubricating oil through the hole from the closed space by gravity changes with time depending on the vibration and the temperature inside the rolling bearing.

It is an object of the present invention to provide a rolling bearing assembly in which the movement of lubricating oil towards the rolling elements in the rolling bearing assembly with improved internal lubrication is increased and controlled.

In an embodiment, the rolling bearing assembly includes an inner ring, an outer ring, at least one row of rolling elements arranged between the inner ring and lace provided to the outer ring, and a circular housing, wherein at least one of the rings Wherein the ring has two half ring portions, each half ring portion having a radial portion and two axially cylindrical portions extending from the radial portion toward the outer portion, wherein two of the rings One of the half ring portions forms a closed space with the circular housing and lubricating oil is arranged in the closed space and at least one half ring portion is provided with passage means for lubricating oil passing from the closed space to the race .

The rolling bearing assembly includes pressure generating means arranged in the closed space at a side facing the passage means.

The lubricating action inside the rolling bearing is improved by the pressure generating means in the confined space and the movement of the lubricant toward the rolling elements can be easily controlled.

Wherein the passage means for the lubricating oil comprises at least one through hole provided in the thickness of at least one part of the ring half of the ring and the pressure generating means comprises at least one through hole in the interior of the housing facing the axial hole It is advantageous to be arranged on the surface.

Wherein the passage means for the lubricant comprises at least one through hole provided in the thickness of the radial portion of the ring portion of the ring and the pressure generating means comprises at least one inner surface of the circular housing facing the axial hole .

The pressure generating means comprises a layer of inflatable material. For example, the material expands when the temperature inside the rolling bearing assembly reaches a predetermined temperature. The predetermined temperature is included between 70 ° C and 250 ° C.

In yet another embodiment, each half ring portion of the ring together with the housing forms a closed space and the lubricant is located in the closed space.

For example, pressure generating means arranged in both closed spaces.

Wherein the passage means for the lubricating oil comprises axial holes provided in the thickness of the radial portion of each half ring portion of the ring and directed at least partially toward one another and each pressure generating means comprises a housing It is advantageous to be arranged on the inner surface.

Each pressure generating means comprises a layer of inflatable material. For example, when the temperature inside the rolling bearing assembly reaches a first predetermined temperature, the first layer arranged in the closed space expands, and when the temperature inside the rolling bearing assembly reaches a second predetermined temperature The second layer arranged in the closed space expands.

In particular, when the temperature inside the rolling bearing assembly is comprised between 70 ° C and 135 ° C, or preferably between 80 ° C and 135 ° C, the first layer arranged inside the confined space is inflated. More precisely, expansion of the second layer is initiated when the temperature reaches a critical temperature, for example between 80 [deg.] C and 95 [deg.] C, and the temperature is, for example, between 120 [ The expansion of the second layer is terminated.

When the temperature inside the rolling bearing assembly is comprised between 100 ° C and 250 ° C, or preferably between 120 ° C and 205 ° C, the second layer arranged inside the other closed space is expanded. More precisely, expansion of the second layer is initiated when the temperature reaches a critical temperature, for example between 120 [deg.] C and 130 [deg.] C, and the temperature is, for example, between 185 [ The expansion of the second layer is terminated.

Advantageously, the housing comprises two divided portions for holding the half ring portion of the ring.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is better understood by studying the detailed description of a number of embodiments contemplated by the embodiments illustrated by the accompanying drawings and not by way of limitation in its entirety.

1 is an axial half sectional view showing an initial state of a rolling bearing according to a first embodiment of the present invention;
2 is an axial half sectional view showing an initial state of a rolling bearing according to a second embodiment of the present invention;
Figure 3 shows the rolling bearing of Figure 2 in use after the temperature has reached a certain level;

1 to 3, the rolling bearing 1 comprises an inner ring 2, an outer ring 3, a ring 5 fixed by means of a cage 5 between the inner ring 2 and the outer ring 3, And in the illustrated embodiment a row of rolling elements 4 consisting of balls and a circular housing 6 surrounding the outer ring 3.

Characterized in that the inner ring (2) has a solid structure and has a toroidal recess (7) at the outer cylindrical surface (2a) of the inner ring, the radius of curvature of the toroidal groove being slightly larger than the radius of the rolling element The toroidal grooves form a bearing race for the rolling elements 4. The inner ring 2 is machined or pressed into a steel blank and then the inner ring is grinded in the bearing race 7 so as to have the geometrical characteristics of the inner ring 2 and the final surface finish, and then lapped.

The cage (5) comprises a plurality of cavities (8) designed to receive and keep the rolling elements (4) uniformly spaced circumferentially. The cavities (8) have a spherical structure with a radius slightly larger than the radius of the rolling elements (4). The cavities 8 are provided within a radial thickness of the cage 5 having a radial portion 5a extending radially inwardly by the conical portion 5b and radially towards the outer ring 3 do. The conical portion 5b is arranged toward the inner ring 2 in the radial direction and extends toward the rolling element 4 in the axial direction. The radial portion 5a and the conical portion 5b form the cavity 8. The conical portion (5b) forms a guiding portion for the rolling elements (4).

The outer ring 3 comprises two half ring portions 3a, 3b or half rings. In order to reduce the manufacturing cost, the half ring portions 3a, 3b are substantially identical and have a symmetrical structure with respect to the axially symmetrical plane Y ₁ of the rolling bearing 1. It is advantageous that the two half ring portions 3a, 3b can be produced by cutting and stamping the metal sheet, and the obtained portion is then hardened by heat treatment. The bearing races for rolling elements 4 may be ground and / or lapped so that the bearing races have a geometric feature and a clear surface finish. The two half ring portions 3a and 3b are the same in the embodiment and one of the half ring portions having the reference symbol "a" is described herein, and the same elements of the other half ring portion 3b Quot; b "

The half ring 3a of the outer ring 3 includes an outer axial cylindrical portion 9a, a radial portion 10a, a toroidal portion 11a and an inner axial cylindrical portion 12a. The radial portion 10a is connected to the outer axial portion 9a and the toroidal portion 11a. The toroidal portion 11a forms a part of the race 13a for the rolling elements 4. The radius of curvature of the race (13a) slightly exceeds the radius of the rolling element (4). The toroidal portion 11a extends axially toward the outer side of the rolling bearing 1 with the inner axial portion 12a. The two half ring portions 3a, 3b are arranged in contact with the radially inner radial surfaces 14a, 14b of the radial portions 10a, 10b.

In this embodiment, the housing 6, which is advantageously made of a stamped metal sheet, has two sections surrounding the half-ring portions for securing the two outer half-ring portions 3a, 3b axially to each other, Shaped circular portions 15,16. It is advantageous that said portions 15, 16 of the housing 6 can be economically produced from a single metal sheet by cutting and pressing. Each of the divided portions 15 and 16 has an L-shaped structure.

The first portion 15 includes an inner axial cylindrical portion 17 for radially holding the outer rings 3a, 3b. The inner axial cylindrical portion 17 surrounds the outer rings 3a and 3b and contacts the outer surfaces of the axial portions 9a and 9b of the outer rings 3a and 3b. The first portion 15 further comprises a radial flange 18 extending from the inner axial cylindrical portion 17 toward a position immediately adjacent the outer cylindrical surface 2a of the inner ring 2 So as to form a gap between the cylindrical surface 2a of the inner ring 2 and the inner side edge 18a of the radial flange 18.

The second portion 16 of the housing 6 includes an outer axial cylindrical portion 19 surrounding the inner axial cylindrical portion 17 of the first portion 15. The second portion 16 further comprises a radial flange 20 extending from the outer axial cylindrical portion 19 toward a position immediately adjacent the outer cylindrical surface 2a of the inner ring 2 , A gap is formed between the cylindrical surface (2a) of the inner ring (2) and the inner side edge (20a) of the radial flange (20). The outer axial cylindrical portion 19 is secured to the inner axial cylindrical portion 17 by welding, brazing or glue.

Optionally, the housing 6 may comprise a single portion having two radial flanges and an axially cylindrical portion extending from the outer axial cylindrical portion toward the inner ring 2.

The half rings 3a and 3b are connected to the first portion 15 of the housing 6 by contact between the inner hole 17a and the axial portions 9a and 9b of the inner axial cylindrical portion 17, In the inner axial cylindrical portion 17 of the inner cylindrical portion 17. The outer radial faces 21a and 21b forming the outer sides of the outer axial portions 9a and 9b are respectively connected to the inner sides of the radial flanges 18 and 20 of the portions 15 and 16 of the housing 6, And contacts the surfaces 18b and 20b to axially fix the two half rings 3a and 3b to each other. The outer radial faces 22a, 22b forming the outer sides of the inner axial portions 12a, 12b contact the radial flanges 18, 20.

Each of the half rings 3a and 3b together with the housing 6 forms a circular closed space 23a and 23b. More specifically, the closed space 23a has an outer axial portion 9a, a radial portion 10a, a toroidal portion 11a, an inner axial portion 12a, and a portion adjacent to these portions Is defined by the radial flange (18) of the first portion (15) of the housing (6).

As shown in FIG. 1, one of the two closed spaces 23a, 23b may serve as a lubricant reservoir. The lubricating oil 25 accommodated in the closed space 23a may be grease or oil. The lubricating oil can be filled into the closed space 23a forming the first lubricating oil reservoir between the half ring 3a and the inner ring 2. Alternatively, lubricant may be filled into the volume formed between the inner ring 2 and the outer ring 3 and into the second closed space 23b.

As shown, the half ring portion 3a of the outer ring 3 includes passage means for the lubricating oil 25 received in the corresponding closed space 23a. 1, the passage means includes at least one and preferably a plurality of axial through holes 24a provided in the thickness of the radial portion 10a of the outer half ring portion 3a do. Each of the through holes 24a is opened toward the inside of the through hole so as to form a passage for flowing the lubricant into the heat flux of the balls 4 between the contact surfaces of the balls 13a and 13b and the balls And is connected to the radial recess or groove 27a. However, optional or supplemental passageway means may be used. For example, radial through holes (not shown in the figures) may be formed in the axial space 12a such that the lubricating oil contained in the closed space 23a can flow toward the rolling element 4 by gravity. May be provided in the thickness.

The rolling bearing (1) further comprises pressure generating means including a layer of inflatable material arranged in the closed space (23a). The layer 26a is arranged on the side of the closed space 23a facing the passage means 24a.

In the embodiment shown in Fig. 1, at first, the layer 26a has a radial plan of the circular housing 6 forming a wall of the closed space 23a at a position facing the axial through hole 24a Is arranged on the inner surface (18b) of the pin (18).

Alternatively, the layer may be arranged on the inner surface of the outer axial cylindrical portion 9a of the half ring portion 3a, and the passage means for the lubricating oil may be arranged on the inner axial cylindrical portion 9a of the half ring portion 3a, And a radial through hole provided within the thickness of the first portion 12a. A layer of inflatable material is arranged in the confined space at a location facing the passage means of the lubricant so that the pressure exerted by the inflatable material exerts the lubricant out of the passage means.

The inflatable material is a material that can expand when the temperature inside the rolling bearing 1 reaches a predetermined temperature. The predetermined temperature is preferably between 70 ° C and 150 ° C and more preferably between 80 ° C and 135 ° C. The expansion of the layer 26a is started when the temperature inside the rolling bearing 1 reaches a predetermined temperature, for example, between 80 캜 and 95 캜, The expansion of the layer is terminated when, for example, the temperature is between 120 ° C and 135 ° C.

The layer 26a may be formed as a circular flat ring made of an inflatable material. Optionally, the layer 26a can be discontinuous and the enclosed space 23a includes discrete patches of inflatable material arranged against the inner surface 18b.

In a preferred embodiment, the layer is made of a material, such as powder, before the lubricating oil is inserted into the half ring portions 3a and / or 3b and the housing 6 is seated to seal the corresponding closed spaces 23a and 23b And projecting particles of a diameter against the surface of the lubricating oil.

The size of the particles at room temperature may be about 10-15 [mu] m.

After reaching a predetermined temperature, for example 70 ° C to 100 ° C, or preferably 80 ° C to 95 ° C, the size of the particles can reach up to 40μm and exhibit a volume increase of about 60 times.

An example of an inflatable material that can be used in the present invention is a material sold under the trademark "Expancel" by Company Microspheres, Akzo Nobel Manufacturer.

2 in which the same components are denoted by the same reference numerals indicate that each of the half ring portions 2a and 2b of the outer ring 3 and the circular housing 6 together with the annular space 23a , 23b, as shown in Fig.

As shown in Fig. 2, the pressure generating means 26a and 26b are arranged so that the respective pressure generating means 26a and 26b arranged in the closed spaces 23a and 23b are connected to the corresponding corresponding passage means 24a and 24b, And a layer of inflatable material arranged on the sides of the closed spaces 23a, 23b. The lubricating oil can flow toward the rolling elements 4 through the holes 24a, 24b and the recesses 27a, 27b. The pressure generating means 26a and 26b are provided on the radial flanges 18 and 20 of the circular housing 6 forming the walls of the corresponding closed spaces 23a and 23b facing the axial through holes 24a and 24b And are arranged on the inner surfaces 18b, 20b.

The first layer 26a is made of a first material that expands at a first predetermined temperature and the second layer 26b is made of a second material that expands at a second predetermined temperature. The expansion of the layer 26a is started when the temperature inside the rolling bearing 1 reaches a predetermined temperature, for example, between 80 캜 and 95 캜, and the temperature inside the rolling bearing 1 For example between 120 [deg.] C and 135 [deg.] C, the expansion of the layer is terminated.

The expansion of the second layer 26b is started when the temperature inside the rolling bearing 1 reaches a predetermined temperature, for example, between 120 DEG C and 130 DEG C, The expansion of the second layer is terminated when, for example, the temperature is between 185 캜 and 205 캜. In this case, different lubrication oils can be used in the two respective sealed spaces 23a, 23b. Alternatively, both layers 26a, 26b may be made of a material that can expand when the temperature reaches a temperature of, for example, 80 deg. C to 95 deg.

Alternatively, the layers may be arranged on the inner surface of the outer axial cylindrical portions 9a, 9b of each half ring portion 3a, 3b, and the passage means may be arranged on the inner surface of the inner half- And may include radial through holes provided within the thickness of the directional cylindrical portion 12a, 12b.

Fig. 3 shows the rolling bearing 1 of Fig. 2 when the temperature rises to a level higher than both predefined temperatures. The volume of each layer 26a and 26b increases and the pressure inside the closed spaces 23a and 23b increases as the volume of each layer 26a and 26b expands and the volume remaining in the free space with respect to the lubricating oil 25 decreases. . The pressure thus formed is pressurized so as to pass the lubricating oil 25 through the corresponding axial through holes 24a and 24b and the corresponding radial grooves 27a and 27b toward the rolling elements 4 and the races 13a and 13b do.

The dimensions of the passage means depend on the lubricating oil used. In fact, when oil is used as the lubricant lot, it has a larger cross-section than the passage means provided when the grease is used as lubricant.

A pressure is created in one or both of the enclosed spaces by the inflatable material provided in the at least one enclosed space. The lubrication of the rolling bearings is improved and controlled while the rolling bearings are being used. The thermal properties of the inflatable material create a pressure within the confined space only when lubricant is needed to lubricate the contact surfaces between the race and rolling elements.

The present invention also has the advantage of forming self regulation of lubrication as the temperature is increased, i.e. the friction on the lace increases due to insufficient lubrication, as the pressure applied to the lubricating oil increases.

Further, since the pressure is not applied to the lubricating oil at room temperature, when the bearing is stored at room temperature, the lubricating oil is maintained in the reservoir formed in one or both of the half rings without risk of leakage.

2 ..... inner ring,
3 ..... outer ring,
13a, 13b ..... race,
4 ..... cloud elements,
6 ..... housing,
3a, 3b ..... half ring part,
Radial part ..... Radial part.

Claims

At least one row of rolling elements 4 arranged between races 13a and 13b provided in the inner ring 2 and the outer ring 3 and at least one row of rolling elements 4 arranged in the circular housing 2, Wherein at least one of the rings (3) is arranged in the housing and the ring (3) comprises two half ring portions (3a, 3b), each half ring portion 3b have radial portions 10a and 10b and two axial cylindrical portions 9a, 9b, 12a and 12b extending from the radial portions 10a and 10b towards the outer side, One of the two half ring portions 3a forms a closed space 23a with the circular housing 6 and the lubricating oil 25 is arranged in the closed space and the at least one half ring portion (3a) includes a passage means (24a, 27a) for lubricating oil (25) passing from said closed space (23a) to said race (13a, 13b) In,
Characterized in that the rolling bearing assembly (1) comprises pressure generating means (26a) arranged in the closed space (23a).

The rolling bearing assembly according to claim 1, wherein the pressure generating means (26a) arranged in the closed space (23a) is located on a side facing the passage means (24a).

A device according to claim 1 or 2, characterized in that the passage means (24a) for the lubricating oil (25) comprises at least one part (9a, 10a, 11a, 12a) of the half ring part (3a) Characterized in that the pressure generating means (26a) is arranged on at least one inner surface (18b) of the housing (6) facing the axial hole (24a) Gt;

A device according to one of the preceding claims, characterized in that the passage means (24a) for the lubricating oil (25)
And at least one through hole provided in the thickness of the radial portion (10a) of the half ring portion (3a) of the ring (3).

The rolling bearing assembly according to any one of the preceding claims, wherein the pressure generating means (26a) comprises a layer of inflatable material.

6. The rolling bearing assembly according to claim 5, characterized in that the material expands when the temperature inside the rolling bearing assembly (1) reaches a predetermined temperature.

7. The rolling bearing assembly of claim 5 or 6, wherein the predetermined temperature is comprised between 70 [deg.] C and 250 [deg.] C.

Wherein half rings (3a, 3b) of the ring (3) together with the housing (6) form sealed spaces (23a, 23b) and lubricant oil (25) Is located on the outer circumference of the rolling bearing assembly.

The rolling bearing assembly according to claim 8, comprising pressure generating means (26a, 26b) arranged in both sealed spaces (23a, 23b).

10. A device according to claim 8 or 9, characterized in that the passage means (24a, 24b) for the lubricating oil (25) are arranged in the radial direction of the radial portions (10a, 10b) of the respective half ring portions Each of the pressure generating means 26a and 26b has an inner surface 18b and 20b of the housing 6 facing the passage means 24a and 24b, ). &Lt; / RTI >

11. A rolling bearing assembly according to claim 9 or 10, wherein each pressure generating means (26a, 26b) comprises a layer of inflatable material.

12. The method of claim 11, wherein the first layer (26a) arranged in the closed space (23a) expands when the temperature inside the rolling bearing assembly (1) reaches a first predetermined temperature and the rolling bearing assembly Is expanded in the second layer (26b) arranged in the closed space (23b) when the internal temperature of the second layer (26b) reaches a second predetermined temperature.

13. The method of claim 12, wherein the predetermined temperature of the first layer (26a) is between 80 DEG C and 135 DEG C, and the predetermined temperature of the second layer (26b) is between 120 DEG C and 205 DEG C Characterized in that the rolling bearing assembly

A rolling bearing assembly according to any one of the preceding claims, characterized in that the housing (6) comprises two divided parts for holding the half ring portions (3a, 3b) of the ring (3).