DE102007060621A1 - Hollow roller body for roller bearing, has connectors accommodate lubricant and fill cavities, and cavities closed on both sides by connectors, where lubricant content of cavities is delivered into roller bearing - Google Patents

Abstract

The body (1) has cavities (2) e.g. bore holes with lubricant content delivered into a roller bearing. Connectors (3) accommodate lubricant and fill the cavities. The cavities are closed on both sides by the connectors and cross hollow roller body. A lubricant-soaked felt, a lubricant-soaked sponge, lubricant-soaked foam plastic and lubricant mixed polyurethane are used as connectors, where the polyethylene is solidified by a heating process.

Description

Field of the invention

The The invention relates to hollow bodies for Roller bearing. Such Hohlwälzkörper be used in rolling bearings to provide a backlash-free, slip-resistant and to ensure quiet operation or speed to be used at high speeds. This Hohlwälzkörper are preferably mounted with preload in the rolling bearing and give increased slip resistance, creating a Improvement of service life compared to play-bearing roller bearings achieved with solid rolling elements.

Background of the invention

Such Hohlwälzkörper for rolling bearings have long been known and, for example in the FR-A-946 559 , of the US-A-3 410 618 , of the FR-A-2 479 369 and the DE 10 2005 048 971 A1 described. According to the FR-A-946 559 Hollow rollers or balls are provided, which can form all the rolling elements of the rolling bearing or which can also alternate with solid rollers or solid balls of smaller diameter. This is intended to ensure that manufacturing tolerances have no influence on the behavior and service life of the rolling bearing. The cavities of the Hohlwälzkörper may be partially or completely filled with another, not specifically described material.

In the US-A-3 410 618 is described a roller bearing, the rollers are designed as hollow rollers. The rollers are arranged with bias between the inner ring and the outer ring, whereby a play-free bearing is formed, the rollers roll off without slippage, so that slippage of the rollers relative to the bearing rings in the unloaded state is avoided. In this roller bearing all roles are designed as hollow rollers.

In contrast, in the FR-A-2 479 369 describes a needle bearing having three evenly distributed on the circumference of the hollow needles, which have a slightly larger diameter compared to the massive needles and thereby bias the bearing. In this way, the life is extended and the noise in the unloaded condition can be reduced.

The same purpose is with the cylindrical roller bearing according to the DE 10 2005 048 971 A1 followed, in which the cylindrical rollers each have an eccentric bore which extends substantially parallel to the longitudinal axis of the cylindrical rollers. The hole can be open or filled with a material that differs from the material of the cylindrical rollers. By such a configuration, the size of the imbalance of the cylindrical rollers can be adjusted by an appropriate choice of material in the eccentric bore to the particular type of use. The material introduced into the bore may have a higher or lower density than the material of the cylindrical rollers. All cylindrical rollers in the cylindrical roller bearing described are provided with the mentioned eccentric bore. According to this document, the slippage occurs predominantly when the load acting on the bearing and transmitted between the bearing rings is comparatively small. If a rolling element then moves with slippage, this means that this rolling element does not roll optimally on the bearing ring and the contact points slide on one another. Increased wear occurs when the lubricating film breaks off and the rolling element transfers load again.

The problem of lubricating film breakage has already been described in accordance with DE 199 59 499 A1 attempts to counteract by between rolling elements at least one rolling element was arranged with pores for receiving and distributing lubricants, wherein the rolling elements having the pores is made of ceramic and so an improved self-lubrication of the bearing should be achieved.

A similar solution to the problem of greasing is in the DE 601 24 096 T2 discloses a rolling bearing with rolling elements, the surface of which has tiny, filled with a lubricant amount depressions, which are flattened in the contact area at the contact points between the rolling elements and the rolling bearing rings and thereby release lubricant on the inlet side of each contact point, resulting in a shift of a at the entry side of each contact point lubricant meniscus further away from the contact point results and results from this displacement of the meniscus a larger lubricant film thickness in each contact area.

In order to ensure a permanent lubrication, if possible without external lubricant supply, which ensures safe operation both at very low and at high temperatures without greasing and without loss of lubricant and a low-noise and low-wear operation, according to the DE 101 21 284 A1 proposed a lubricant composition containing a polyurethane and a lubricant. Polyurethanes can be mixed in a favorable manner with various lubricants, and thereby arise materials that have particularly favorable, self-lubricating properties, can easily be brought by pouring to the lubrication point or can be processed into moldings, such as rolling bearing cages. Here, the lubricant contained in the polyurethane molded body is on the rolling elements ü so that adequate lubrication is ensured without lubricant loss.

A similar purpose is a lubricant for rolling bearings according to the DE 29 13 781 A1 consisting of a mixture of grease and highly monocular or low mononuclear polyethylene solidified by heating. This lubricant can be adjusted so tightly that it can produce bearing cages, which have an oily surface by oil separation and thereby ensure the bearing lubrication.

Object of the invention

Of the Invention is based on the object, a Hohlwälzkörper to propose for a rolling bearing through which Use in rolling bearings this an increased slip resistance has, can be used at high speeds, for a minimum quantity lubrication is suitable or with additional Lubricant is supplied, no high starting resistance cold conditions, not under these conditions Howling tends and has a long life.

Description of the invention

According to the Features of the main claim this object is achieved by a hollow rolling element for rolling bearings, in the cavity of a deliverable in the bearing lubricant filling is introduced. The rolling bearing can with only one or a few Hollow rolling elements with a lubricant filling be provided, but also all rolling elements the rolling bearing as Hohlwälzkörper with a Be formed lubricant filling. This way will the cavity of Hohlwälzkörpern for recording used a lubricant filling, and there are no consuming to be produced porous Keramikwälzkörper or with tiny, filled with a lubricant amount Depressions on the rolling element surface required. Nor is it necessary, the bearing cages made of a lubricant containing material containing the lubricant at the rolling elements and the career gives, but It can caged materials with better mechanical Properties are used so that producing one with bodies of the invention hollow provided rolling bearing greatly simplified and particularly cost is.

Preferably the cavity is at least partially by a lubricant filled receiving medium, where as Carrier medium Lubricant-soaked felt, lubricated natural or synthetic sponge, lubricant-soaked foam plastic, lubricant mixed with polyurethane or mixed with lubricant and polyethylene solidified by heating.

The Carrier medium stores the lubricant and gives it in Operation dosed in a suitable manner. The release of the lubricant in the rolling bearing or in the contact zones, namely the rolling contact with the bearing rings and the cage contact, into it is on the one hand by the centrifugal forces of the rotating Rolling and on the other hand by the elastic Compression of the hollow roller body when passing through causes the load zone of the bearing. This will be a Load-dependent control of the lubricant quantity automatically realized. This results from the fact that the Hohlwälzkörper depending on the attacking load different degrees elastic springs, causing the inside of the rolling element located carrier medium according to load is compressed and releases a corresponding amount of lubricant.

Of the Field of application of the rolling bearing with the invention Hollow rolling elements extends to rolling bearings with increased slip resistance, for high speeds are suitable and allow a lightweight construction. In particular, aims the invention to applications with minimal quantity lubrication. Also in applications where the lubricant has a high starting resistance forms, for example, at very low ambient temperatures of, for example below -20 ° C, rolling bearings are with the invention Hollow rolling ideal.

such Applications are important for ball bearings in belt tensioners, in pulleys or in belt calming rollers in aggregate mode an internal combustion engine. Here is the problem that it at very low ambient temperatures for the so - called howling of the Belt tensioners can come. Particularly vulnerable are here Belt tensioners, which have a small wrap angle and a low total roll force resulting from the ring forces exhibit. The previously used lubricant, usually grease, is at low ambient temperatures, eg. Eg -25 ° C, so firm that the rolling elements grease at start of operation can not durchwalken and displaced the fat from the tracks becomes. In this state, the rolling bearing begins howl, which is usually after 10 to 20 seconds, as soon as the lubricant has heated due to friction, again disappears, but judged to be an unacceptable malfunction becomes.

Roller bearings with the lubricant-filled hollow rolling bodies according to the invention are furthermore advantageously usable if high demands are placed on the service life of the bearing and an additional lubricant is to be made available for this purpose. Likewise, the invention is advantageously used in rolling bearings whose grease Volume space is greatly reduced, if only a limited space is given due to a tight osculation or a ball roller construction or a special cage construction in the form of a massive, strong enclosing cage. Rolling bearings that need to be designed for minimum quantity lubrication are, for example, hard disk bearings for avoiding or limiting grease outgassing, or bearings in the food industry. In addition, a so-called combination lubrication can be realized with the lubricant-filled Hohlwälzkörpern invention, in which the rolling bearing is initially lubricated by default with a lubricant type X and the lubricant-filled Hohlwälzkörper another type Y lubricant is introduced, for example has a higher viscosity and thus has better lubricating properties at higher temperatures. As a result, the life of the rolling bearing can be extended in an advantageous manner or the upper limit of its temperature range can be shifted upwards.

Of the Cavity is preferably through a hollow roller body formed by passing through the bore, the two sides by the plug trained Trägerme medium is closed, with the as Plug formed carrier medium the hole completely can fill, or it can be designed as a stopper Carrier medium for closing the hole two spaced, forming a space within the bore Parts exist. In this embodiment, the clearance between the spaced stuffing parts filled with a lubricant reserve be. In addition to the free space that can be designed as a stopper Carrier medium for receiving a lubricant reserve hollowed out or the space for the lubricant reserve becomes exclusive through a cavity in the carrier medium formed as a stopper educated.

in the Case of trained as balls rolling elements or rolling elements such as rollers or needles with convex End surfaces, at least one side of the plug trained carrier medium with a rolling element adapted convexity be formed.

The also claimed rolling bearing can with at least one Hollow body be provided with the aforementioned features, wherein the number of arranged in the rolling bearing, according to the invention Hollow rolling elements according to the intended use directed and a maximum of all rolling elements in the rolling bearing can include. The invention Rolling elements can be used otherwise Standard lubrication of the rolling bearing with a type X lubricant, either an additional one Quantity of lubricant of the same type or an additional one Provide quantity of type Y lubricant with different properties.

Brief description of the drawings

Some preferred embodiments inventively trained Hollow rolling elements are referred to below explained in more detail in the accompanying drawings. Showing:

1 a longitudinal sectional view of an inventively designed hollow roller with a cavity completely filling, lubricant-saturated carrier medium;

2 a longitudinal sectional view of an inventively designed hollow roller with a space for receiving a lubricant reserve;

3 a further embodiment of a hollow roller body according to the invention formed with designed as a convex caps carrier medium caps;

4 a longitudinal sectional view of a hollow roller formed as a needle roller according to the invention with a closed by the carrier medium bore and formed as a lubricant reservoir cavity.

Detailed description the drawings

In 1 is one as a ball 1 trained rolling element recognizable, which is a cavity-forming bore 2 having. This hole 2 is by a plug 3 forming carrier medium completely filled. The carrier medium contains the lubricant and releases it during operation from the rolling bearing, not shown. By doing that, the plug 3 has rectilinear side surfaces, the rolling element is designed as a ball roller.

The embodiment according to 2 shows two, the hole 2 closing, spaced plugs 4 formed by the carrier medium, such that one between the spaced plugs 4 educated open space 5 is usable as a lubricant reserve.

The embodiment according to 3 differs from the embodiments according to the 1 and 2 in that the split stopper 6 From cavities 7 have, so that the volume of the lubricant reserve from the free space 5 as well as the excavations 7 exists and is thereby considerably increased. Furthermore, the plugs have 6 the shape of the sphere 1 adapted convex end surfaces 12 on, so that in the embodiment according to 3 a complete ball is given.

The embodiment according to 4 shows a needle roller 8th with an axial bore 9 passing through a stopper 10 is closed, which is formed by the carrier medium. In the stopper 10 is a hollow 11 present, which serves as a lubricant reserve. Again, there is more lubricant in the plug 10 forming carrier medium. The stopper 10 has convex end faces 12 on, however, the end surfaces can also be straight.

When the lubricant receiving carrier medium are lubricated soaked Felt, grease-soaked sponge, lubricated Foamed plastic, lubricant mixed with polyurethane or with Lubricant mixed and heat strengthened polyethylene in question.

The Dispensing of the lubricant into the bearing or into the contact zones is caused by the centrifugal forces of the rotating and on the raceways rolling rolling elements and by the elastic deflection of the hollow roller body when passing through the load zone of the bearing causes. There the hollow roller body as a function of the elastic load springs in different ways is located in the interior of the rolling element Carrier medium compressed according to load, as a result, depending on the degree of compression each a certain amount of lubricant is released, wherein the compression and thus the lubricant delivery by adjusting the Wall thickness of the hollow roller body adjustable is. Depending on the consistency of the selected carrier medium can when relieving due to the decompression again lubricant be absorbed by the carrier medium.

1

rolling elements, Bullet

2

Cavity, drilling

3

Carrier medium Plug

4

Plug, divided

5

free space

6

Plug, divided

7

erosion

8th

rolling elements, Roll or needle roller

9

Cavity, drilling

10

Carrier medium Plug

11

erosion

12

convex end surfaces

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• FR 946559 A [0002, 0002]
• - US 3410618 A [0002, 0003]
• FR 2479369 A [0002, 0004]
• DE 102005048971 A1 [0002, 0005]
• - DE 19959499 A1 [0006]
• - DE 60124096 T2 [0007]
• - DE 10121284 A1 [0008]
• DE 2913781 A1 [0009]

Claims (16)

Hohlwälzkörper ( 1 . 8th ) for rolling bearings, characterized by a deliverable in the rolling bearing lubricant filling of the cavity ( 2 . 9 ) of the hollow roller body ( 1 . 8th ). Hollow rolling element according to claim 1, characterized by a cavity ( 2 . 9 ) at least partially filling, the lubricant receiving carrier medium ( 3 . 4 . 6 . 10 ). Hollow rolling element according to claim 2, characterized by lubricant-soaked felt as the carrier medium ( 3 . 4 . 6 . 10 ). Hollow rolling element according to claim 2, characterized by a lubricant-impregnated sponge as the carrier medium ( 3 . 4 . 6 10 ). Hollow rolling element according to claim 2, characterized by lubricant-soaked foam plastic as the carrier medium ( 3 . 4 . 6 . 10 ). Hollow rolling element according to claim 2, characterized by lubricant mixed with polyurethane as the carrier medium ( 3 . 4 . 6 . 10 ). Hollow rolling element according to Claim 2, characterized by polyethylene mixed with lubricant and solidified by heating as the carrier medium ( 3 . 4 . 6 . 10 ). Hollow rolling element according to one of claims 1 to 7, characterized by a cavity of the hollow rolling element ( 1 . 8th ) forming, the Hohlwälzkörper ( 1 . 8th ) passing through, on both sides by the plug ( 3 . 4 . 6 . 10 ) formed carrier medium sealed bore ( 2 . 9 ). Hollow rolling element according to claim 8, characterized in that the plug ( 3 ) formed carrier medium the bore ( 2 ) completely. Hollow rolling element according to claim 8, characterized in that the plug ( 4 . 6 ) formed carrier medium for closing the bore ( 2 ) from two spaced, a free space ( 5 ) in the hole ( 2 ) forming parts. Hollow rolling element according to claim 10, characterized in that the free space ( 5 ) is filled with a lubricant reserve. Hollow rolling element according to claim 9 or 10, characterized in that the plug ( 1 . 8th ) formed carrier medium for receiving a lubricant reserve hollowed out ( 7 . 11 ). Hollow rolling element according to one of claims 8 to 12, characterized in that in the case of as balls ( 1 ) trained rolling elements or rolling elements such as rollers or needles ( 8th ) with convex end surfaces ( 12 ) at least one side of the plug ( 6 . 10 ) formed carrier medium with a rolling element ( 1 . 8th ) adapted convexity ( 12 ) is trained. Rolling bearing with at least one hollow rolling element ( 1 . 8th ) according to one of claims 1 to 13. Rolling bearing according to claim 14, characterized in that it is lubricated as standard with a lubricant type X and the at least one Hohlwälzkörper ( 1 . 8th ) provides an additional amount of lubricant of the same type. Rolling bearing according to claim 14, characterized in that it is lubricated as standard with a lubricant type X and the at least one Hohlwälzkörper ( 1 . 8th ) provides an additional amount of Y-type lubricant.