WO2012150056A1

WO2012150056A1 - Rolling bearing

Info

Publication number: WO2012150056A1
Application number: PCT/EP2012/053708
Authority: WO
Inventors: Markus STÜTZLEIN
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2011-05-04
Filing date: 2012-03-05
Publication date: 2012-11-08
Also published as: DE102011075249A1

Abstract

The invention relates to a rolling bearing having two sets of rolling elements, wherein in order to achieve slip-free rolling contact in a load state of low load, one set of rolling elements is designed having spherical rolling surfaces (1) and having a slightly greater diameter relative to the other set of rolling elements. According to the invention, the rolling elements having spherical rolling surfaces (1) each comprise at least one hollow space (2) in the supporting region in order to increase the elasticity thereof.

Description

Name of the invention

Rolling bearing description

Field of the invention

The invention relates to a rolling bearing with two sets of rolling elements, wherein for slip-free rolling contact in a load state of low load, a set of rolling elements with spherical rolling surfaces and with respect to the other set of rolling elements slightly larger diameter is formed.

Background of the invention

Such a rolling bearing is known from DE 103 48 207 B4. There, a double-row slip-free spherical roller bearing is described in which each row of rolling elements consists of balls and rollers. In order to ensure a slip-free operation of the pendulum roller bearing in a low load condition, the smallest outer diameter of the balls is made larger than the largest outer diameter of the rollers. A disadvantage of this embodiment, the fact that at higher loads on the balls high pressures occur, whereby the life of the bearing is severely limited. Object of the invention

The invention is therefore based on the object in a rolling bearing of the aforementioned type on the rolling elements with spherical rolling surfaces to avoid high pressures in order to increase the life. The object is solved by the features of claim 1. Summary of the invention

Since the rolling elements with spherical rolling surfaces each have at least one cavity in order to increase their elasticity in the supporting region, their elasticity can be significantly increased. In this way, significantly lower pressures are achieved in the rolling contact with the same deformation, whereby the life of the rolling bearing significantly increased and this can be used permanently, especially at high load conditions. Preferably, the rolling elements with spherical rolling surfaces in the non-supporting region are at least partially flattened deviating from the spherical shape. In order to form at least one cavity, at least one recess may be provided starting from the flattening and extending at least in sections in the supporting region. At the same time, the flattening serve to guide or to start the rolling elements.

In a particularly preferred embodiment of the invention, the rolling elements are formed with spherical rolling surfaces as ball hollow rollers with flattened parallel side surfaces and a passage opening from one side surface to another. The ball hollow rollers are preferably each with a central through hole, for example, a through hole executed, which forms a symmetrical to the rolling axis cavity.

In a particularly preferred embodiment of the invention, the rolling bearing is designed as a slip-free spherical roller bearing with a set of barrel rollers and a set of hollow spherical rollers.

Preferably, the spherical roller bearing axially adjacent two rows of running, wherein in each row of barrel rollers and ball hollow rollers are arranged alternately one behind the other. As a result, an optimized ratio of slip avoidance and load capacity as well as a uniform distribution of the masses and the load in the rolling bearing is achieved. To simplify manufacture and assembly, the barrel and ball hollow rollers of both rows of rollers can be arranged in a common roller cage. Preferably, the barrel rollers are each formed with a diameter which is greater than their length. Such a so-called "over-square" barrel rolls have a high rigidity and at the same time allow a particularly narrow and high construction of the spherical roller bearing In a further particularly preferred embodiment of the invention, the barrel and ball hollow rollers are arranged such that a barrel roll of a row of a ball hollow roller of the other This enables non-slip spherical roller bearings in narrow series, which are at the same time easy to manufacture and assemble, It is also conceivable to arrange the opposite barrel and ball hollow rollers offset from one another ,

The barrel rollers can be performed in a simple manner by arranged between the rows of rollers guide means. Such guide means may be formed, for example, as a co-rotating separate guide ring or integrally with the bearing inner ring as a so-called "mid-board".

Brief description of the drawings

Further features of the invention will become apparent from the following description and from the drawings, in which an embodiment of the invention is shown in simplified form. 1 shows a perspective partial view of a rolling bearing according to the invention,

Figure 2 is a schematic partial section of the rolling bearing. Detailed description of the drawings

1 shows a section of a slip-free rolling bearing according to the invention is shown, which is designed as a double-row spherical roller bearings. Between a bearing inner ring 7 and a bearing outer ring, not shown, rolling elements are guided in two rows axially next to each other. Each of the two rows of rollers consists of barrel rollers 4 and ball hollow rollers, which are arranged alternately one behind the other in the circumferential direction. The spherical hollow rollers have spherical rolling surfaces 1 which terminate in parallel side surfaces 3 which are flattened in a different manner than the spherical shape. To increase its elasticity, a cavity 2 formed by a central through-hole from one side surface 3 to the other is provided on the ball hollow rollers.

In the unloaded state, the spherical hollow rollers are at the spherical rolling surfaces 1 in punctiform rolling contact, while the barrel rollers 4 have a linear rolling contact. Opposite the barrel rollers 4, the ball hollow rollers are designed with a slightly larger diameter. In the low-load phase, the ball-and-roller set thus ensures slip-free operation. The barrel rollers 4 come into play in the high load phase. Due to the higher load, the ball hollow rollers deform elastically until the higher stiffness having barrel rollers 4 mitbarer with their smaller diameter. Due to the through-bore, the ball-shaped hollow rollers have a significantly higher elasticity than, for example, solid balls or ball rollers. As a result, significantly less pressure is produced on the hollow ball rollers with the same insertion. In this way, the carrying capacity of the barrel rollers 4 can be better utilized.

Barrel rollers 4 and hollow ball rollers of both rows of rollers are arranged in a rolling element cage 5 and lie in each case obliquely opposite each other. The rolling element cage 5 facing side surfaces 3 of the ball hollow rollers form contact surfaces. FIG. 2 shows, in an axial partial section, the arrangement of the barrel rollers 4 and ball hollow rollers guided side by side in two rows of runs. At the bearing outer ring, the raceway 8 is formed spherically for the rolling elements. The barrel rollers 4 and the ball hollow rollers adjust themselves on the spherical raceway 8 of the bearing outer ring. Bearing inner ring 7, 5 Wälzkörperkäfig and rolling elements can be so pivot by a few degrees from a central position to compensate for misalignment, especially the deflection of a shaft. Compared to the conventional "ball" rolling element, all non-bearing areas are removed from the hollow ball roller, the conventional ball shape being indicated by dashed lines, thus creating a ball flattened on both sides with parallel side surfaces 3. In this way, the ball hollow roller is considerably narrower than a ball appropriate space can be saved or the ball hollow roller can be adjusted in its axial width to a predetermined space.

The central through hole between the side surfaces 3 along the rolling axis 9 of the ball hollow roller forms a cavity 2 open on both sides in the bearing area enclosed by the spherical rolling surfaces 1. The cavity 2 increases the elasticity in the supporting area significantly. When loaded by the rolling contact on the rolling surfaces 1 so the pressure in the bearing area is significantly lower with the same deformation of the ball hollow rollers. As a result, in the high-load phase, we enable a greater deflection of the ball hollow rollers without them becoming tired, whereby the roller blocks 4 can simultaneously take over the high load.

The barrel rollers 4 are guided by guide means 6 on the bearing inner ring 7. The guide means 6 are arranged centrally between the rows of runs and formed here by way of example as a separate guide ring. The barrel rollers 4, in particular their length, and the guide ring define a spherical roller bearing space, which remains to receive the ball hollow rollers. In this case, the ball hollow rollers must correspond to the curvature of the spherical Track 8 on the bearing outer ring can kinematically align without causing overlaps with the guide ring and the barrel rollers 4. In the exemplary embodiment shown, so-called "over-square" barrel rollers 4 are used whose diameter is greater than their length In this way, spherical hollow rollers can be used whose diameter is greater than the length of the barrel rollers 4. This makes it possible to perform multi-row slip-free spherical roller bearings in particularly narrow and high series.

Rolling surface

cavity

side surface

tons role

Rolling Element

guide means

Bearing inner ring

career

rolling axis

Claims

claims

Rolling bearing with two sets of rolling elements, wherein for slip-free rolling contact in a load state of low load a set of rolling elements with spherical Wälzflächen (1) and with respect to the other set of rolling elements slightly larger diameter is formed, characterized in that the rolling elements with spherical Wälzflächen (1) each have at least one cavity (2) to increase their elasticity in the supporting area.

Rolling bearing according to claim 1, characterized in that the rolling elements with spherical Wälzflächen (1) in the non-supporting area are at least partially flattened deviating from the spherical shape, wherein on the flattening at least one cavity (2) forming recess is provided which is at least partially extends in the supporting area.

Rolling bearing according to claim 1 or 2, characterized in that the rolling elements are formed with spherical rolling surfaces (1) as ball hollow rollers with parallel side surfaces (3) and a central passage opening from one side surface (3) to the other.

Rolling bearing according to one of claims 1 to 3, characterized in that the rolling bearing is designed as a spherical roller bearing with a set of barrel rollers (4) and a set of hollow spherical rollers, wherein in two rows of barrels (4) and ball casters alternately in a row in a Wälzkörperkäfig (5) are arranged

Rolling bearing according to one of claims 1 to 4, characterized in that the barrel rollers (4) each have a diameter which is greater than their length. Rolling bearing according to one of claims 1 to 5, characterized in that a barrel roller (4) of a row of rollers of a ball hollow roller of the other row of rollers is axially opposite and vice versa.

Rolling bearing according to one of claims 1 to 6, characterized in that for guiding the barrel rollers (4) arranged between the rows of rollers guide means (6) are provided.