GB2390648A

GB2390648A - Roller bearing with integrated meshing means

Info

Publication number: GB2390648A
Application number: GB0312734A
Authority: GB
Inventors: Jean-Jacques Forest
Original assignee: Societe Nouvelle de Roulements SNR SA
Current assignee: NTN SNR Roulements SA
Priority date: 2002-06-05
Filing date: 2003-06-03
Publication date: 2004-01-14
Anticipated expiration: 2023-06-03
Also published as: FR2840657B1; GB0312734D0; GB2390648B; FR2840657A1

Abstract

A roller bearing comprises a rotating inner race (1) provided with two separate raceway assemblies (4, 5) and, mounted on it, two fixed outer races (2, 3) each provided with at least one raceway (6, 7) disposed respectively opposite one of the raceway assemblies (4, 5). Rolling bodies (22-24) are disposed between the respective raceways (4-7), and the inner race (1) comprises on its outer periphery a meshing means (9) which is provided between the two raceway assemblies (4, 5). An actuation device comprising such a roller bearing, and an application of such a device for the deployment and retraction of a high-lift system of a wing unit of an aircraft is also disclosed.

Description

1 2390648

ROLLER BEARING WITH INTEGRATED MESHING MEANS

The invention relates to a roller bearing for a bearing, an actuation device comprising such a roller bearing and an application of such a device for the deployment and retraction of a high-lift system of a wing unit of an 5 aircraft.

When it is wished to actuate a mechanical element, the use is known of a device comprising a meshing member set into rotation by a drive shaft, said member being arranged to cause the setting in motion of the element to be actuated.

10 In order to provide rotation, the device also comprises at least one roller bearing for a bearing provided with a rotating inner race intended to be associated with the meshing member and a fixed outer race intended to be immovably attached to a fixed structure.

15 Such devices, for example described in the documents US-1 917 428 and EP-0 291 328 within the context of a use for the

deployment and retraction of a high-lift system of a wing unit of an aircraft, have a number of drawbacks.

In particular, especially in applications such as the one under consideration where the transmitted forces are large, S it is necessary to use specific means of mounting the roller bearing on the meshing member in order that the device is capable of withstanding these forces both in the axial direction and in the radial direction so as not to risk either breaking up of the roller bearing or a loss of 10 efficiency of the actuation device.

Consequently, the devices of the prior art are complex and

have a large number of components, which is detrimental in terms of total mass of the device, assembly and dismantling times, and reliability.

15 The invention aims to resolve these drawbacks by proposing in particular an actuation device comprising a roller bearing for a bearing integrating a meshing means.

To that end, and according to a first aspect, the invention proposes a roller bearing for a bearing of the type 20 comprising a rotating inner race provided with two separate raceway assemblies and, mounted on it, two fixed outer races each provided with at least one raceway disposed respectively opposite one of the raceway assemblies, rolling bodies being disposed between the respective raceways, in 25 which the inner race comprises on its outer periphery a meshing means which is provided between the two raceway assemblies. According to a second aspect, the invention proposes an actuation device comprising a motor driving a shaft, said 30 shaft being associated with the rotating race of at least one roller bearing as defined above.

According to a third aspect, the invention proposes an application of such an actuation device for the deployment and retraction of a high-lift system of a wing unit of an aircraft. 5 Other objects and advantages of the invention will emerge in the course of the following description, given with

reference to the accompanying drawings, in which: - Figure 1 is a view in longitudinal section of a roller bearing for a bearing according to a first embodiment of the 10 invention; - Figure 2 is a partial view in longitudinal section of an actuation device comprising the roller bearing of Figure 1, said device being depicted in its operating environment; Figure 3 is a view in longitudinal section of a roller 15 bearing according to a variant of the first embodiment of Figure 1.

A description is given of a roller bearing for a bearing

comprising a rotating inner race 1 and, mounted thereon, two fixed outer races 2, 3.

20 The inner race 1 is provided with two separate raceway assemblies 4, 5 which are implemented in the vicinity of each end of the external transverse surface of the inner race 1.

The internal transverse surface of each outer race 2, 3 is 25 provided with at least one raceway 6, 7 which are disposed respectively opposite one of the raceway assemblies 4, 5.

In order to allow the relative rotation of the inner race 1 with respect to the outer races 2, 3 about an axis 8,

rolling bodies are disposed between the respective raceways 4-7. In the description, the terms "external,' and "internal" are

defined with respect to a plane respectively away from and 5 close to the axis 8, the terms "axial" or "transverse" are defined with respect to a plane parallel to the axis 8, and the terms "radial" or "lateral" are defined with respect to a plane perpendicular to the axis 8.

According to the invention, the inner race 1 comprises on 10 its outer periphery a meshing means 9 which is provided between the two raceway assemblies 4, 5. The meshing means 9 is intended to cooperate with a complementary meshing means 10 provided on the element to be actuated 11.

Thus, the roller bearing according to the invention, by 15 integrating the meshing means g which comes in one piece with the inner race 1, is of particularly simple construction and can be used in an actuation device comprising a motor driving a shaft 12, said shaft being associated with the rotating race 1.

20 As shown in Figure 2, the roller bearing can be easily integrated into its operating environment, in particular on account of the meshing means 9 being provided between the two fixed outer races 2, 3. The outer races 2, 3 each comprise a side plate 13 provided with means of fixing said 25 race onto a fixed structure 14. In the embodiment depicted, the fixing means are formed of an orifice 15 intended to allow joining by bolting.

Moreover, the inner race 1 comprises a bore 16 into which the shaft 12 is intended to be fitted so as to rotationally 30 drive said inner race 1 and therefore the meshing means 9.

In the embodiment depicted, the periphery of the bore 16 is

provided with a second meshing means 17 which is intended to cooperate with a complementary meshing means 18 provided on the shaft 12. In a variant, the same shaft 12 can be fitted into the inner race 1 of several roller bearings according 5 to the invention, for example when the element to be actuated 11 is large in size and must therefore be provided with several complementary means 10 for providing precise guidance of the motion of the element 11.

In the embodiment depicted, the meshing means 9, 17 are 10 formed of a plurality of teeth 19 which extend radially.

The complementary means 18 of the shaft 12 is formed of complementary teeth 20 so as to provide a reliable rotational coupling, said teeth possibly coming in one piece with the shaft 12 or being added on. The complementary 15 means 10 of the element to be actuated 11 is formed of a rack 21 in which said teeth 19 are intended to engage in order to allow the conversion of the rotational motion of the inner race l into a translational motion of the element 11, said translation being performed in one direction or the 20 other according to the direction of rotation of the shaft 12. Moreover, the two meshing means 9, 17 are situated substantially in the same radial plane, so as to limit the shear forces induced in the roller bearing during actuation.

25 In one particular example, the device is intended to be used for actuating the deployment and retraction of a high-lift system of a wing unit of an aircraft. High-lift system means the flaps and leading edge slats which are conventionally used in variable geometry wing units, said 30 system being either deployed in order to increase the lift of the wing unit in the case in particular of the low speed flight phases, or retracted in order to reduce it in the

case in particular of the high speed flight phases so as to reduce the drag of the wing unit and thus contribute towards lower fuel consumption of the aircraft.

In this particular application, the element to be actuated 5 11 is the body of the high-lift system which generally comprises several curved racks 21 which are intended to cooperate with as many roller bearings, the outer races 2, 3 of said roller bearings being associated with the main body of the wing 14 and the inner races 1 being associated in 10 series on the shaft 12. The rotation of the shaft 12 is then actuated selectively in one direction or the other by the pilot of the aircraft according to the geometry of the wing unit which is adapted to the flight conditions existing at the time.

15 In such an application, the forces undergone by the roller bearing are relatively large, both in an axial direction and in a radial direction, all the more so since the meshing means 9 is integrated into the inner race 1 of the roller bearing. 20 In particular, under the effect of the actuation forces, the inner race 1 has a tendency to have an angular deflection with respect to the outer races 2, 3, which could result in breaking up of the roller bearing.

But, on the contrary, the roller bearing must not be too 25 rigid, that is to say respective motions of the races 1-3 must be possible under force, so as to not risk breaking the roller bearing.

In order to satisfy this dual constraint, provision is made for the roller bearing to comprise the following 30 characteristics:

- the first assembly 4 comprises two adjacent toric raceways 4a, 4b; - the first outer race 2 comprises a concave spherical raceway 6 which is disposed opposite the first assembly 4; 5 - two rows of spherical rolling bodies 22, 23 are disposed respectively between a boric raceway 4a, 4b and the spherical raceway 6; - the second assembly 5 comprises a convex spherical raceway 5a; 10 - the second outer race 3 comprises a cylindrical raceway 7 which is disposed opposite the second assembly 5; - a row of cylindrical rolling bodies 24 is disposed between the spherical raceway 5a and the cylindrical raceway 7.

Thus, the outer races 2, 3 are axially locked on account of 15 their connection to the fixed structure 14, and the inner race l is also axially locked on account of the raceways 4a, 4b, 7. Furthermore, the raceways 5a, 6 are arranged to allow the angular tilting of the inner race 1 with respect to the outer races 2, 3 and vice versa. The roller bearing 20 can then function despite a misalignment of the inner 1 and outer 2,3 races since it is the whole of the inner race 1 which tilts with respect to the outer races 2, 3 or vice versa, and not in particular one assembly of the inner race 1 with respect to the outer race 3, 4 placed opposite.

25 In particular, the presence of the first three characteristics on the one hand makes it possible to substantially lock the inner race 1 on one side and on the other hand allows relative rotational movements of the outer race 2 placed opposite, while the presence of the last three 30 characteristics on the one hand makes it possible to

substantially lock the second outer race 3 and on the other hand allows relative rotational movements of the part of the inner race 1 placed opposite.

Moreover, the respective presence of the two rows of 5 spherical rolling bodies 22, 23 and of the row of cylindrical rolling bodies 24 makes it possible to increase the resistance capability as regards radial forces, the respective curvature of the spherical raceways 6, 5a makes it possible to allow a certain freedom of relative 10 rotational movement of the races 1-3, and the presence of the cylindrical 7 and toric 4a, 4b raceways makes it possible to provide the axial cohesion of the roller bearing. The combination of the characteristics mentioned above is 15 particularly advantageous when several roller bearings have to be mounted on the same shaft 12 since it limits the phenomena of angular misalignment thereof, and therefore makes it possible to accept a certain flexing of the shaft 12 without risking a loss of efficiency of the actuation 20 device.

In the embodiment depicted in the figures, sealing means 25 are provided in the vicinity of each end of the internal transverse surface of the outer races 2, 3, said means extending radially in order to come into frictional contact 25 on respectively one part of the inner race 1. Thus, it is possible, on the one hand, to effectively combat possible contamination of the roller bearing areas and, on the other hand, to avoid the discharge of lubricant outside said areas. 30 In the variant depicted in Figure 3, the parts of the inner race l on which the sealing means rub have a finite radius of curvature, and in particular are substantially spherical,

so as to limit the wear of the sealing means 25, for example formed from elastomer, which is induced by said frictional contact. An actuation device according to the invention therefore 5 comprises a significantly reduced number of components and consequently has less mass. This reduction allows faster maintenance and non-negligible savings in terms of down time of the aircraft on the ground. Moreover, the device is also simplified by proposing a ready-to-install assembly which 10 the aircraft manufacturer can easily put together on his assembly lines.

Claims

1. A roller bearing for a bearing of the type comprising a rotating inner race provided with two separate raceway assemblies and, mounted on it, two fixed outer races 5 each provided with at least one raceway disposed respectively opposite one of the raceway assemblies, rolling bodies being disposed between the respective raceways, said roller bearing being characterized in that the inner race comprises on its 10 outer periphery a meshing means which is provided between the two raceway assemblies, 2. A roller bearing according to Claim 1, characterized in

that the inner race comprises a bore, the periphery of which is provided with a second meshing means, 15 3. A roller bearing according to Claim 2, characterized in that the two meshing means are situated substantially in the same radial plane.

4. A roller bearing according to any one of Claims 1 to 3, characterized in that the meshing means is or are 20 formed of a plurality of teeth which extend radially.

5. A roller bearing according to any one of Claims 1 to 4, characterized in that: - the first assembly comprises two adjacent toric raceways; 25 the first outer race comprises a concave spherical raceway which is disposed opposite the first assembly;

- two rows of spherical rolling bodies are disposed respectively between one toric raceway and the spherical raceway, 6, A roller bearing according to any one of Claims 1 to 5, 5 characterized in that: - the second assembly comprises a convex spherical raceway; the second outer race comprises a cylindrical raceway which is disposed opposite the second assembly; 10 - a row of cylindrical rolling bodies is disposed between the spherical raceway and the cylindrical raceway. 7. A roller bearing according to any one of Claims 1 to 6, characterized in that the outer races each comprise a 15 side plate provided with means for fixing said race onto a fixed structure.

8. A roller bearing according to any one of Claims 1 to 7, characterized in that sealing means are provided in the vicinity of each end of the internal transverse surface of 20 the outer races, said means extending radially in order to come into frictional contact on respectively one part of the inner race.

9. A roller bearing according to Claim 8, characterized in that the parts of the inner race on which the sealing 25 means rub have a finite radius of curvature.

10. An actuation device comprising a motor driving a shaft, said shaft being associated with the rotating race of at least one roller bearing according to any one of Claims 1 to 9.

11. Application of a device according to Claim 10 for the deployment and retraction of a high-lift system of a wing unit of an aircraft.

12. A roller bearing substantially as described with reference to and as shown in Figure 1 or Figure 3 of the accompanying drawings.

13. An actuation device substantially as described with reference to and as shown in Figure 2 or modified as described with reference to and as shown in Figure 3 of the accompanying drawings.