DE102008020069A1 - Inclined roller bearing i.e. taper roller bearing, for e.g. swash plate axial-piston pump, has inner annular gaps and outer annular gap comprising side walls that run parallely, and plastic cage formed as contactless seal - Google Patents

Abstract

The bearing (1) has rollers (5) that unroll between an inner ring (3) and an outer ring (4). The rollers are guided from a plastic cage (11). The plastic cage comprises molded side rings (12, 13) that radially form interior annular gaps (15a, 15b) with the inner ring at an inner side, and radially form outer annular gaps (16a, 16b) with the outer ring at an outer side. The inner and outer annular gaps comprise side walls that run parallely. The plastic cage is formed as a contactless seal. The plastic cage comprises transverse bars (14) that are arranged between the rollers.

Description

The The invention relates to a tapered roller bearing, in particular a tapered roller bearing, for example, for use in a hydraulic machine, with an inner ring, an outer ring, a plastic cage and a plurality of rollers, wherein Roll the rollers between the inner ring and the outer ring and held by the cage, with the plastic cage has at least one molded side ring which radially inside with the inner ring an inner annular gap and radially on the outside with the outer ring an outer Annular gap forms. The invention further relates to a machine with this tapered roller bearing.

Tapered roller bearings, as an embodiment of tapered roller bearings, generally consist of an outer ring, an inner ring, each with tapered raceways, and tapered rollers, with the tapered rollers often guided by a cage made of pressed sheet steel or held. Tapered roller bearings take high radial and one-sided axial Loads on.

Already from the publication DE 2419944 A1 It is known that tapered roller bearings generate a pumping action due to the tapered cage surfaces, which promotes a lubricating oil from the side with the smaller inlet diameter to the side with the larger inlet diameter of the rolling bearing. In the cited document is proposed to control the lubricating oil production by using a temperature-sensitive device, namely a device with a bimetallic component.

From the publication DE 27 39 367 , which is probably the closest prior art, another tapered roller bearing, in particular a tapered roller bearing is known. The tapered roller bearing has a plastic cage, which has cross struts and molded-on side rings and is guided between an inner and an outer ring of the rolling body.

Of the The invention is based on the object, the functional behavior of Tapered roller bearings, in particular tapered roller bearings, especially for use in an oil medium to improve.

These Task is by a tapered roller bearing with the features of claim 1 and with a machine with the tapered roller bearing solved with the features of claim 7. Preferred or advantageous Embodiments of the invention will become apparent from the subclaims, the following description and the accompanying figure.

in the Within the scope of the invention is a tapered roller bearing, in particular proposed a tapered roller bearing, which is preferred for the use in a hydraulic machine or pump and / or in an oil bath or in another liquid suitable and / or trained is.

The Tapered roller bearing comprises an inner ring, an outer ring, a plastic cage and a plurality of rollers, in particular Tapered rollers, which between the inner ring and the outer ring are arranged rolling and held by the plastic cage become.

Of the Plastic cage is preferably in one piece and / or exclusively made of plastic and has axial at least one molded side ring on the end. In alternative Embodiments, the plastic cage is multi-part educated. The side ring is in the tapered roller bearing arranged so that this radially inward with the inner ring an inner annular gap and radially outside with the Outer ring forms an outer annular gap. Of the or each annular gap points in a cross section perpendicular to the axis of rotation of the tapered roller bearing an annular shape, wherein the rings at the outer annular gap by the outer ring and the side ring and the inner annular gap be formed by the inner ring and the side ring.

in the Under the invention, it is proposed that the inner and the outer Annular gap respectively parallel side walls and / or concentric with each other have arranged side walls.

Of the Course of the annular gap in the axial direction is at the inner annular gap preferably cylindrical and the outer Ring gap prefers funnel-shaped or cone-shaped, but also cylindrically shaped.

alternative or in addition, the inner and outer show Annular gap in its extension in the axial direction a constant Gap diameter. In a first definition, the gap diameter becomes in the cross-sectional plane perpendicular to the axis of rotation of the tapered roller bearing measured. In a second possible definition of the Gap diameter perpendicular to the extension direction of the annular gap in a longitudinal section parallel to the axis of rotation of the tapered roller bearing measured.

More generally, the plastic cage is formed as a non-contact seal, which prevents an oil flow through the Wälzkörperraum. This function is preferably implemented in that the plastic cage is formed large volume and fills most of the available in the Wälzkörperraum, free volume. The available volume in the Wälzkörperr Preferably, the total volume, that is to say the annular gap, less the space required for the rollers and less the necessary tolerances, is preferred, in order to permit low-friction operation of the tapered roller bearing. The remaining volume is preferably filled to at least 60%, in particular at least 80% and in particular to at least 90% through the plastic cage.

A consideration The invention is that it is advantageous if the tapered roller bearing a Pumping or conveying function takes over to a sufficient To ensure proper lubrication of the tapered roller bearing. However, especially at high operating speeds, it has as disadvantageous when a large volume of oil flows through the roller set, as the oil through the Roles must be displaced. This repression work However, especially at high speeds increases the rotational resistance of the tapered roller bearing and thus the power loss the tapered roller bearing. To the power loss of storage Therefore, it is proposed to reduce the free torus or Wälzkörperraum with the plastic cage shut off and thus the oil flow rate and the Panschverluste to reduce. This goal is achieved through a constructively adapted, especially large volume plastic cage achieved which minimizes or controls the oil flow rate.

at a preferred embodiment of the invention is provided that the gap or the diameter over the entire axial Extension of the plastic cage the smallest distance from the plastic cage to the inner ring or to the outer ring represents or represent. Thus already forms the side ring one Throttle or a seal for the oil off. One minimum distance between plastic cage and outer or inner ring remains in place to allow free movement of the plastic cage to reach between the rings.

at In a particularly preferred embodiment, the plastic cage guided by the rollers in the axial direction, in particular the plastic cage is guided board-free in the axial direction.

at a preferred embodiment of the invention, the plastic cage two such side rings on. One of the side rings, below as well as the large side ring designates, it is in diameter formed larger than the other side ring, which is hereinafter referred to as a small side ring. Preferably is the gap diameter at the inner and / or outer annular gap each formed the same size for both side rings. In this embodiment, the rolling body space Sealed or throttled on both sides by the side rings. All in all Through the use of side rings, the flow resistance through the angular contact ball bearings increased. Considering, that a flow direction through the different Diameter of the small and the large side ring, the flow direction of the small side ring is directed to the large side ring, so forms the smaller Side ring an input seal and / or the large side ring an outlet seal for the oil.

at an optional supplement to the invention has the plastic cage Cross struts, which are arranged between the rollers and are integrally formed on the side rings. The cross struts form together with the outer ring in the direction of rotation, at least partially an outer annular gap, ie annular gap sections between the roles. The outer ring gap forms together with the outer annular gap of the big one and / or the small side ring a common, continuous Annular gap. In this preferred embodiment has the common annular gap has a constant gap diameter in the axial course, wherein the gap diameter is preferably perpendicular to the splitter extension is measured. By this measure, the flow resistance, in particular in the areas between the roles, further increased. Prefers is the gap diameter of the common annular gap except for one For the operation necessary tolerance minimized.

at a preferred embodiment of the invention, the inner ring two shelves for lateral guidance of the rollers, wherein the shelves together with the plastic cage or the forming inner annular gaps.

at a modified embodiment may also be the outer ring have two shelves for lateral guidance of the rollers and the inner ring together with the cross struts and the inner annular gap of the large and / or small side ring a common Annular gap with an axially constant gap diameter form.

The Invention also relates to a machine with a tapered roller bearing, as described above or according to one of the preceding Claims, wherein the tapered roller bearing in a Liquid bath, in particular oil bath, arranged is. Especially in an oil environment are the initially described Benefits of the invention exploited.

Especially Advantageously, the invention proves when the tapered roller bearing is used for storage of a high-speed machine part. Under fast running are preferred revolutions of more than 300 revolutions per minute, in particular more than 3,000 revolutions per minute and in particular understood by more than 10,000 revolutions per minute.

at A particularly preferred application of the invention is the Machine designed as a hydraulic pump or a hydraulic motor. at an exemplary application, the roller bearing for storage the drive shaft of a swash plate in a swash plate axial piston pump or Swash plate axial piston motor or a hydrostatic Gear used, with the rotating swash plate arranged to a lifting movement of in a rotating cylinder Piston leads.

Further Features, advantages and effects of the invention will become apparent the following description and the attached figures an embodiment of the invention. Showing:

1 a schematic longitudinal section through the axis of rotation of a tapered roller bearing as an embodiment of the invention.

1 shows a tapered roller bearing 1 in a longitudinal section parallel to the axis of rotation 2 tapered roller bearing 1 ,

The tapered roller bearing 1 has an inner ring 3 and an outer ring 4 on, between which a plurality of tapered rollers 5 are rotatably mounted. The outer ring 4 shows in the longitudinal section shown an approximately triangular shape, wherein the tapered roller 5 facing side one with respect to the axis of rotation 2 cone-shaped tread 6 represents.

The inner ring 3 has a cone-shaped inner tread 7 on, which in the longitudinal section shown angled to the tread 6 is aligned, and two lateral, integrally molded shelves 8a and 8b for axial guidance of the tapered roller 5 ,

The tapered roller 5 shows a frusto-conical shape, rolling between the inner and outer tread 7 respectively. 6 off and is in a border area by the shelves 8a , b guided in the axial direction. The rotation axis 9 the Ke gelrolle 5 is steep-angle, so with an angle relative to the axis of rotation 2 of more than 20 °, formed in this embodiment of about 30 °. In alternative embodiments, said angle may also be in a range between 2 ° and 20 °. Due to the different axial distance of the end faces of the tapered roller 5 from the axis of rotation 2 During operation, a flow direction for an oil in the direction of the arrow 10 ,

For spacing the tapered rollers 5 facing each other, the tapered roller bearing 1 a plastic cage 11 on, which consists of an inner side ring 12 , an outer side ring 13 as well as between the side rings 12 . 13 and the tapered rollers 5 arranged cross struts 14 consists. The plastic cage 11 is integrally formed and located radially on the outside of the tread 6 of the outer ring 4 and radially inside on the Borden 8a , b on. The plastic cage 11 is not in the axial direction through the shelves 8a , b led.

In the area of the small side window 12 is through the side window 12 and the inner board 8a or the inner ring 3 an inner annular gap 15a and through the small side ring 12 and the outer ring 4 an outer annular gap 16a educated. In an analogous way, in the case of the large side ring 11 an inner annular gap 15b with the board 8b and an outer annular gap 16b with the outer ring 4 educated. The inner annular gap 15a , B have a constant gap diameter d1 over their axial course. The outer annular gap 15a , b also show a constant gap diameter d2, which - as in 1 shown - perpendicular to the extension direction of the annular column 15a , b is determined.

The gap diameters d1 and d2 are preferably minimally designed so that a maximum flow resistance is formed, but without falling below the tolerances necessary for safe and low-friction operation. As is clear from the 1 results, the gap diameter d1 is greater than the gap diameter d2 selected.

Will the displacement volume through the revolving tapered rollers 5 set to 100%, 70% of the displacement volume take the standing tapered rollers 5 and 6% the cage bars 14 one. The remaining 24% are free volumes. In other embodiments, the cage bars take 14 up to 10% or more of the displacement volume. In general, the cage webs preferably occupy more than a quarter or more than one third of the displacement volume remaining after deduction of the rolling bodies.

Due to the minimized gap diameter d1, d2 are at the small or large side ring 12 respectively. 11 generates maximum flow resistance. With the aim to further increase the total flow resistance, the cross struts 14 designed so that the outer annular gap 16a respectively. 16b with constant gap diameter d1 also in the area of the cross struts 14 is continued. This results in a common annular gap over the entire axial width of the plastic cage 9 , which - in the sense of a labyrinth seal - has a very high flow resistance. The common annular gap is in the direction of rotation through the tapered rollers 5 interrupted.

The tapered roller bearing is preferred 1 in a hydraulic pump or hydraulic machine, in particular in a pressure-loaded area, ie at Operating pressures of over 100 bar and used in an oil environment. Alternatively, the tapered roller bearing 1 also in a transmission, in particular in a differential gear, z. B. as a shaft bearing, are used. Due to the structural design of the plastic cage 9 is achieved that due to the pumping action in the pumping direction 10 through the tapered roller bearing 1 flowing oil is minimized, since the plastic cage 9 largely shuts off the free torus or Wälzkörperraum by the high flow resistance. In this way, on the one hand, the flow rate of oil and on the other hand, the Panschverluste reduced. Compared with commonly used tapered roller bearings with a sheet metal cage, a reduction in power loss by up to 30% is expected.

1

Tapered roller bearings

2

axis of rotation

3

inner ring

4

outer ring

5

Tapered roller

6

cone-shaped, outer tread

7

inner tread

8a, b

Borde

9

axis of rotation

10

Arrow, pumping direction

11

Plastic cage

12

internal Side ring, side window

13

outer side ring

14

crossmember

15a, b

internal Annular gap, cross struts

16a, b

outer annular gap

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

• - DE 2419944 A1 [0003]
• - DE 2739367 [0004]

Claims (9)

Tapered roller bearings ( 1 ), in particular tapered roller bearings, for example for use in a hydraulic machine, with an inner ring ( 3 ), an outer ring ( 4 ), a plastic cage ( 11 ) and a plurality of roles ( 5 ), where the roles ( 5 ) between the inner ring ( 3 ) and the outer ring ( 4 ) and from the plastic cage ( 11 ), wherein the plastic cage ( 11 ) at least one molded side ring ( 12 . 13 ), which radially inwardly with the inner ring ( 3 ) an inner annular gap ( 15a , b) and radially outside with the outer ring ( 4 ) an outer annular gap ( 16a , b), characterized in that the inner and the outer annular gap ( 15a , b, 16a , b) each having parallel side walls and / or the plastic cage ( 11 ) is designed as a non-contact seal. Tapered roller bearings ( 1 ) according to claim 1, characterized in that the gap diameter (d1, d2) over the entire axial extent of the plastic cage ( 11 ) the smallest distance to the inner ring ( 3 ) or outer ring ( 4 ). Tapered roller bearings ( 1 ) according to one of the preceding claims, characterized in that the plastic cage ( 11 ) two such side rings ( 12 . 13 ), wherein the one side ring - hereinafter also referred to as a large side ring ( 13 ) - a larger inner diameter and / or outer diameter than the other side ring - hereinafter as a small side ring ( 12 ) - has. Tapered roller bearings ( 1 ) according to claim 3, characterized in that the plastic cage ( 11 ) Crossbars ( 14 ), which between the rollers ( 5 ) are arranged and in one piece on the side rings ( 12 . 13 ) are formed, wherein the transverse webs ( 14 ) together with the outer ring ( 4 ) form an outer annular gap in sections in the circumferential direction, wherein the outer annular gap together with the outer annular gap ( 16a , b) the large and / or the small side ring ( 13 . 12 ) form a common annular gap which has one or the constant gap diameter in the axial extent. Tapered roller bearings ( 1 ) according to claim 4, characterized in that the inner ring ( 3 ) two shelves for lateral guidance of the rollers ( 5 ) having. Tapered roller bearings ( 1 ) according to one of the preceding claims, characterized in that the entire, available annular gap between inner ring ( 3 ) and outer ring ( 4 ) is completely or largely completely filled by the annular gaps, the rollers and the plastic cage. Machine with a tapered roller bearing ( 1 ) according to one of the preceding claims, characterized in that the tapered roller bearing ( 1 ) runs in a liquid bath. Machine according to claim 7, characterized in that the tapered roller bearing ( 1 ) is operable and / or operated at high speed, in particular at more than 300 revolutions per minute, in particular at more than 3,000 revolutions per minute. Machine according to claim 7 or 8, characterized that the machine is considered a hydraulic pump or motor, for example is designed for mounting a swash plate.