WO2011162729A2

WO2011162729A2 - The bearing with plastic segmented cage

Info

Publication number: WO2011162729A2
Application number: PCT/SK2011/050009
Authority: WO
Inventors: Juraj Senko; František HRTÁNEK; Miroslav MASÁR
Original assignee: Psl, A.S.
Priority date: 2010-06-26
Filing date: 2011-06-26
Publication date: 2011-12-29
Also published as: SK500272010A3; WO2011162729A3

Abstract

The purposes of this invention are a simplification of bearing cage segment's construction, facilitation of assembly and increasing the reliability of operation of the bearing with plastic segmented cage. Segments (2) comprise of side plates (21), interconnected at least by two crossbars (22) in such a way, that there are the pockets (24) created between the crossbars (22) for placing of rolling elements (3). Each pocket (24) contains a capture (23) on the inner surface (211) of at least one side plate (21), which is radially located outside the centre of the side plate's height (21) and tangentially in the centre between side walls (221) of adjacent crossbars (22). The capture (23) has advantageous shape of nose made up on the side plate (21), adjacent to the functional face (31) of rolling element (3).

Description

THE BEARING WITH PLASTIC SEGMENTED CAGE

Technical Field

This invention relates to a bearing with plastic segmented cage, particularly for large-size radial tapered roller bearing that is suitable for mounting the rotor of wind-power plant.

Background Art

In order to decrease cost and simplify the production of bearing cages for large-size anti-friction bearings having diameter over 1000 mm, the bearing cages are produced from plastic segments. These segments are produced either in the form of separate, mutually detached spacing elements that separate the individual rolling elements in the bearing, or in the form of boxes, in which the pockets are made, serving for placement of one or more rolling elements. The pockets are restricted by inner surfaces of segment’s side plates and by cross-bars connecting the side-plates of segment. For enabling the assembly of complete bearing, the rolling elements in segments of box type must be secured against the falling out from pocket.

The solution of the tapered roller bearing with plastic segmented cage of box type is known from the Patent document no. WO 2006/094661. The peripheral guidance of rolling elements in the pockets is provided by the cylindrical surfaces created on the adjacent cross-bars. In order to prevent to falling the rolling elements out of pockets, the distance between the opposite edges of pockets´ cylindrical surfaces is less than the diameter of rolling element. Elements are inserted into the pocket gradually in such way, that element is placed on the input opening of pocket and a pressure acts on it, whereby within limits of elasticity, the edges of socket’s opposite cylindrical surfaces move away each other and the element enters into the pocket. Consequently, the edges of opposite cylindrical surfaces of pocket will return to the original positions, which results in securing the rolling element against dropping out.

Disadvantages of the known state of technology are as follows; a significant pressure force must be used for pushing the element into the pocket, because the contact area of edges of pocket’s opposite cylindrical surfaces with peripheral area of the rolling element is large and an abrasion of the edges of edges of pocket’s opposite cylindrical surfaces may result during operation of the bearing, which can be reason for dropping the elements out of pocket at later dismantling the bearing. Another disadvantage of the known state of technology is, that cage segment must be produced with high precision. In case of not observing the accuracy of segment’s dimensions, there is a danger that element cannot be inserted into the pocket.

Disclosure of Invention

Above mentioned imperfections are eliminated to a great extent by the bearing with plastic segmented cage, whose segments consist of the side plates connected using at least two cross-bars in such way, that there are the pockets created between them, serving for placing the rolling elements inside. The substance of this invention consists in the fact that in each pocket there is a capture made on inner surface of at least one of side plates, while the capture is radially positioned outside the centre of the side plate height and tangentially in the centre between side plates of adjacent cross-bars. Such solution allows safety seating of the rolling element into the pocket of bearing cage, resistant to the dropping of the bearing element out of the pocket during assembling the bearing. The pressure force, necessary for inserting the rolling element into the pocket of bearing cage is minimal, because contact area of the capture with front area of rolling element is very small. At the same time, the demands for accuracy of segment’s dimensions are substantially decreased and variability of segment construction is increased.

Moreover, the subject-matter of the invention consists in the fact, that the capture has shape of a nose, made up on the side plate adjacent to the functional face of the rolling element, while the distance between the top of nose and inner surface of the opposite side plate is shorter than the length of rolling element. This solution allows advantageously utilize a technological opening made on functional face of the rolling element for snapping the capture of nose shape.

Furthermore, the substance of this invention consists in the fact, that the height of the cross-bars is less than the height of side plates, which allows considerable decreasing the thickness of cross-bars that occupy the space determined for the rolling elements in reduced extent. The bearing can therefore be equipped by optimum number of the rolling elements, which favourably influence the increase of bearing’s carrying capacity.

The substance of this invention consists also in the fact that radius of curvature of cross-bar’s side walls is greater than radius of peripheral surface of the rolling element, which results in the linear contact of the peripheral surface of rolling elements with side walls of crossbar that has favourable influence to lubricating conditions in the bearing.

Finally, the substance of this invention consists in the fact, that the adjacent segments contact each other by their face surfaces, which has favourable influence to stable seating of cage’s segments in the bearing without necessity to furnish the ends of segments by components for mutual connection of the segments.

Brief Description of Drawings

The invention will be explained in details using the drawings, in which it is illustrated the following:

Fig. 1 is a perspective view of the complete bearing with segmented cage,

Fig. 2 is a perspective view of the complete segmented cage,

Fig. 3 is a top view of the bearing cage’s segment,

Fig. 4 is a perspective view from bottom of the bearing cage’s segment,

Fig. 5 is a front view of tapered rolling element with opening on the functional face.

Best Mode for Carrying Out the Invention

The anti-friction bearing illustrated in Fig. 1 consists of the outer ring 1 and the inner ring 5, the rolling elements 3 disposed between them, seated in the cage illustrated in Fig. 2, consisting of seven segments 2. As it is visible from figures, the adjacent segments 2 contact each other through its face surfaces 213.

Segment

2 showed in Figs. 3 and 4 is made up of the side plates 21, linked using six cross-bars 22 in such a way, that five pockets 24 for placing the rolling elements 3 are created between cross-bars 22. In each pocket 24 there is the capture 23 made on the inner surface 211 of one side plate 21 in the shape of nose. The capture 23 is positioned radially outside the centre of the side plate’s height 21 and tangentially in the centre between side plates 221 of adjacent crossbars 22. The distance between the top of capture 23 and inner surface 211 of the opposite side plate 21 is smaller than the length of rolling element 3. Rolling element 3 an opening 311 on its functional face 31. The height of cross-bars 22 is smaller than the height of side plates 21 and radius of curvature of the sides 221 of cross-bars 22 is greater than radius of peripheral surface 32 of rolling element 3.

During assembly of complete bearing, at first all the rolling elements 3 are seated into the pockets 24 of segments 2, and in this way prepared segments 2 are placed on the inner ring 5 of bearing side by side in such a way, that adjacent segments 2 contacts each other through its face surfaces 213 till the cage is closed all over its periphery. Consequently, the outer ring 1 is placed on the cage. Rolling elements 3 are seated into pockets 24 of segments 2 in such a way, that these individual rolling elements 3 are gradually slipped by its opening 311 made on functional face 31 onto noses serving as the captures 23, and using the soft pressure, in consequence of elastic deformation of the side plates 21 are inserted inside the pocket 24. After placing the rolling element 3 into the pocket 24 due to elasticity the side plates 21 will return to the initial position, whereby the rolling element 3 is secured against dropping out from the pocket 24 during assembly of complete bearing.

Claims

The bearing with plastic segmented cage, whose segments (2) comprise of side plates (21), interconnected using at least two crossbars (22) in such a way, that the pockets (24) are created between the cross-bars (22) for seating the rolling elements (3), characterized by the fact that in each pocket (24) there is the capture (23) made up on the inner surface (211) of at least one side plate (21), while the capture (23) is radially positioned outside of the centre of the side plate’s height (21) and tangentially in the centre between the side walls (221) of adjacent cross-bars (22).
The bearing with plastic segmented cage according to claim 1, characterized by the fact that the capture (23) has shape of a nose, made up on the side plate (21) adjacent to the functional face (31) of rolling element (3), while the distance between the top of capture (23) and the inner surface (211) of the opposite side plate (21) is smaller than the length of rolling element (3).
The bearing with plastic segmented cage according to claim 1 or 2, characterized by the fact that the height of cross-bars (22) is smaller than the height of side plates (21).
The bearing with plastic segmented cage according to claim 1 or 2 or 3, characterized by the fact that radius of curvature of side walls (221) of cross-bars (22) is greater than radius of peripheral surface (32) of rolling element (3).
The bearing with plastic segmented cage according to any of above mentioned claims, characterized by the fact that adjacent segments (2) contact each other by their face surfaces (213).