WO2019110045A1

WO2019110045A1 - Rolling bearing having integrated pressure sealing

Info

Publication number: WO2019110045A1
Application number: PCT/DE2018/100968
Authority: WO
Inventors: Benjamin Rudin
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2017-12-06
Filing date: 2018-11-28
Publication date: 2019-06-13
Also published as: DE102017128937A1; CN111433473B; CN111433473A; DE102017128937B4

Abstract

The invention relates to a rolling bearing (1) having an inner ring (9) and an outer ring (2), wherein rolling bodies (3) are arranged between the inner ring (9) and the outer ring (2). Furthermore, an annular disc (4) is arranged between the outer ring (2) and the inner ring (9), at least on the pressure side. There is provision that the annular disc (4) is received in a form-fitting manner in a recess (15) of the outer ring (2) or of the inner ring (9), and a shoulder (16) is formed on the annular disc (4), a closed sealing ring (5) being fitted onto said shoulder.

Description

Rolling bearings with integrated pressure seal

The invention relates to a rolling bearing with an integrated pressure seal according to the preamble of the independent claim.

To seal off pressures in dual-clutch transmissions, plastic rings made of a polyamide-imide are used. These plastic rings are designed as slotted rings in the manner of a piston ring and can be inserted by a corresponding expansion in grooves, in which they snap after withdrawal of the clamping force to stretch the ring. Operating pressures of up to 6 bar oil pressure with low leakage can be sealed by means of such polyamide imide rings. Such plastic rings are inserted in grooves on the dual-clutch transmission at suitable locations and are connected upstream of the roller bearings. The bearings have a sealing washer. The oil pressure presses the plastic ring in the axial direction against a flank of the groove in which the plastic ring is received, and thus activates the sealing effect of the plastic ring. As a result, the rolling bearing is not exposed to the high operating pressures, so that a simple sealing of the rolling bearing is possible or possibly completely eliminated.

From DE 10 2009 006 649 A1 discloses a dual-clutch transmission is known in which a transmission shaft is rotatably supported by means of a rolling bearing. The rolling bearing is preceded by a plastic sealing ring in order to reduce the oil pressure acting on the rolling bearing.

However, a disadvantage of the known solutions is that a plastic sealing ring arranged upstream of the roller bearing requires additional installation space. Further, at least one additional groove for locking the plastic sealing ring is necessary, whereby an additional processing of a component on the pressure side, in particular in a dual-clutch transmission is necessary. The object of the invention is to provide a rolling bearing with an integrated pressure seal, which allows a seal against the environment significantly increased operating pressures in a compact and inexpensive design.

According to the invention the object is achieved by a rolling bearing with an inner ring and an outer ring, wherein between the inner ring and the outer ring a plurality of rolling elements are arranged, and wherein between the outer ring and the inner ring, at least on the pressure side, an annular disc is arranged. In this case, the annular disc is received in a recess of the outer ring or of the inner ring in a form-locking and / or force-locking manner, wherein a shoulder is formed on the annular disc on which a closed sealing ring is mounted. As a result, a limited axially displaceable sealing ring is integrated into the rolling bearing, so that a comparatively high sealing effect is achieved. At the same time, the sealing ring is subjected to a pressure increase on the pressure side of the rolling bearing, i. The side, on which a higher operating pressure prevails, is displaced in such a way that it is pressed against a contact surface and can thus close a sealing gap. By activating the sealing ring by the operating pressure of an operating fluid, in particular an oil, on the pressure side and the associated pressing of the sealing ring against an abutment surface can be compared to the ambient pressure increased operating pressures of 2bar or more sealed, which with known sealing lips on a rolling bearing can not be sealed and lead to leakage. As a result of the axial movability, the sealing ring can be released again from the contact surface when the operating pressure on the pressure side falls, so that a suppression in the area of the rolling elements and a reduced lubrication of the rolling element caused thereby is avoided.

The features listed in the dependent claims advantageous improvements and developments of the rolling bearing specified in the independent claim are possible.

In a preferred embodiment of the invention, it is provided that a chamfer is provided on a side of the annular disc facing the rolling body, which kitchen ends at the landing. By a chamfer on the annular disc, the mounting of the sealing ring can be facilitated and the risk of damage to the sealing ring when mounting can be reduced.

In a further improvement of the invention, it is provided that a shoulder is formed on the inner ring of the rolling bearing. Through a shoulder, the hydraulic activation of the sealing ring can be improved with an increase in pressure on the pressure side of the rolling bearing. In doing so, the sealing ring is flowed under a more favorable angle and on a more favorable surface, so that it can be activated more easily, i. is pressed in the axial direction against a stop surface.

It is preferred if between the annular disc and the inner ring, a sealing gap is formed, wherein the sealing gap extends in a first portion parallel to a support surface of the inner ring and in a second portion at an angle a to the first portion. A sealing gap can prevent larger particles from penetrating into the roller bearing and thus damaging the sealing ring or jamming the sealing ring, so that hydraulic activation of the sealing ring is no longer possible. By a sealing gap, which extends in the first portion parallel to a support surface of the inner ring and extends in a second portion at an angle to this first portion, a particularly favorable flow of the sealing ring for axial activation is possible, thereby avoiding that penetrated into the sealing gap Impurities can be deposited on the sealing surface and thus adversely affect the sealing effect of the sealing ring.

It is particularly preferred if a bevel is formed on the sealing ring on its side facing the shoulder. By a bevel on the shoulder of the inner ring facing side of the sealing ring, a deflection of the sealant can be carried out in the groove, whereby a particularly simple hydraulic activation of the sealing ring is possible. In addition, contaminants that have penetrated into the roller bearing through the sealing gap can deposit in the groove, so that they are kept away from the hydraulically sealing surfaces and are deposited on the groove base. In a preferred embodiment of the invention it is provided that the bevel has an angle β in the range of 10 ° to 45 °, preferably between 20 ° and 40 °. Through a chamfer at an angle of 10 ° to 45 °, the flow of oil through the sealing gap on the sealing ring is best used to activate the sealing ring, so that the sealing ring starts axially against a contact surface of the inner ring and seals the second sealing gap. The inner diameter of the sealing ring is preferably in the range of ± 1 mm of the shoulder diameter of the shoulder on the inner ring, so that an optimal activation of the sealing ring can take place.

In an advantageous embodiment of the invention, it is provided that on the inner ring a groove for releasing the sealing ring is formed. By means of a corresponding groove on the inner ring, sufficient space can be created in the radial direction so that the sealing ring can be displaced in the axial direction without contact on the inner ring and thus activated and deactivated. On the other hand, this creates a space in which impurities that have penetrated into the sealing gap can deposit without being pressed against the sealing ring and thus without leading to increased wear on the sealing ring.

According to a preferred embodiment of the invention it is provided that on the inner ring, a stop surface is formed, wherein between the sealing ring and the stop surface of the inner ring, a second sealing gap is formed. By an integrated into the inner ring stop surface can be formed in a simple and inexpensive way, an axial stop for the sealing ring. In addition, as a result of the second sealing gap, provided that it is open when the sealing ring is not in contact with the stop, lubricant flows into the area of the rolling elements, so that the danger of a negative pressure in the bearing and a concomitant reduced lubricant supply is eliminated becomes.

In a preferred embodiment of the invention, it is provided that the sealing ring is made of a high-temperature-resistant, chemical and abrasion-resistant plastic material, preferably of a polyamide-imide material. Polyamideimide The high thermal stability up to more than 200 ° C and the high resistance to chemicals as well as the high abrasion resistance compared to other plastics. Therefore, a Polyamidimidring is particularly suitable as a sealing ring in a rolling bearing according to the invention, since even with the axial displaceability unlike a sealing ring made of an elastomer no increased wear and thus a correspondingly high durability is to be expected. In addition, a closed sealing ring made of a polyamideimide can be produced inexpensively in an injection molding process.

According to an advantageous development of the rolling bearing is provided that the shoulder of the annular disc and the groove on the inner ring are each wider than the sealing ring, so that the sealing ring in the axial direction between corresponding stop surfaces on the inner ring and on the annular disc is displaceable. Due to the limitations of the axial mobility of the sealing ring on the annular disc and on the inner ring, a simple activation and deactivation of the sealing ring is possible. It is ensured that the sealing ring is not tilted or lost, since the width of the groove and the width of the stop surface are each only slightly wider than the width of the sealing ring.

The various embodiments of the invention mentioned in this application are, unless stated otherwise in the individual case, advantageously combinable with each other.

The invention will be explained in more detail with reference to a preferred embodiment and the accompanying drawings. It shows:

1 shows an embodiment of a rolling bearing according to the invention with integrated pressure seal in a sectional view.

In Fig. 1, an embodiment of a rolling bearing 1 according to the invention is shown with an integrated pressure seal. The rolling bearing 1 according to the invention comprises an outer ring 2 and an inner ring 9 and between the outer ring 2 and the inner ring 9 arranged rolling elements 3. Further, the rolling bearing 1 according to the invention comprises a fixed to the outer ring 2 annular disc 4, which is arranged on the pressure side between the inner ring 9 and the outer ring 2 is and closes the Wälzläger 1 on the pressure side to a sealing gap 12. The annular disc 4 is preferably pressed into the outer ring 2, wherein a shoulder 15 is provided on the outer ring 2, which serves as a stop for the annular disc 4 during pressing. On the annular disc 4, a chamfer 8 is formed on its side facing the rolling element 3, in order to allow damage-free mounting of a closed sealing ring 5, in particular a closed sealing ring 5 made of a polyamide-imide material, on a shoulder 16 of the annular disc 4. The rolling bearing 1 is preferably formed as a ball bearing, but other forms of rolling elements 3 are possible.

The inner ring 2 has, at its end facing the pressure side, a shoulder 7 which separates the sealing gap 12 from a groove 10 on the inner ring 9. On its side facing the shoulder 7, the sealing ring 5 has a chamfer 19 with an angle β of 0 ° to 45 °, preferably of 20 ° to 40 °, through which the oil pressure p a of the pressure side in the rolling bearing 1 depressed oil 6 is passed through the sealing gap 12 on the chamfer 19 of the sealing ring 5, so that the sealing ring 5 is activated accordingly and axially against a stop surface 18 on the inner ring 9 is pressed. As a result, a sealing gap 13 between the sealing ring 5 and the inner ring 9 is closed so that the area of the rolling elements 3 is sealed against the oil pressure p on the pressure side of the rolling bearing 1. By the displacement of the sealing ring 5, a sealing space 11, which is bounded by the shoulder 7, the groove 10, the sealing ring 5 and the annular disc 4 increases. The sealing gap 12 has a first section 12a, which runs parallel to a support surface 17 of the inner ring 9 and a second section 12b, which at an angle a of 0 ° to 45 °, preferably 10 ° to 40 ° to first section runs, wherein the angle a substantially corresponds to the angle of the shoulder 7.

On the annular disc 4, a stop surface 20 is formed, which limits the axial movement of the closed sealing ring 5 in the direction of the pressure side. The Diameter DD of the sealing ring 5 is preferably in the range of ± 1 mm of the shoulder diameter Ds, so that an optimal activation of the sealing ring 5 can take place. The groove 10 has a groove bottom 14 with a diameter DN, which lies below the shoulder 7. In this case, the groove bottom 14 is preferably 1 mm to 5 mm below the shoulder 7, so that in the radial direction sufficient space for the sealing ring 5 and a movement of the sealing ring 5 is present.

In a simplified embodiment of the invention, both the angle a between the shoulder 7 and the support surface 17 of the inner ring 9 and the angle ß are selected on the sealing ring = 0 °. In this simplified embodiment, the sealing ring thus has a rectangular cross section and the shoulder 7 coincides with the groove base 14 of the groove 10. This variant has the advantage that it is particularly easy to manufacture and inexpensive to produce, but can lead to a limited sealing effect and an associated increased leakage at the rolling bearing 1.

If the oil pressure p of the oil 6 increases on the pressure side of the rolling bearing 1 according to the invention, then this oil pressure p is throttled through the sealing gap 12. Furthermore, the sealing gap 12 prevents penetration of larger particles in the rolling bearing 1, which could damage the sealing ring 5. The oil pressure p shifts the sealing ring 5 in the axial direction in the direction of the abutment surface 18 on the inner ring 9, whereby the second sealing gap 13 between the sealing ring 5 and the inner ring 9 is closed. Due to the oil pressure p, the sealing ring 5 is pressed against this stop surface 18, whereby even medium pressures, in particular oil pressures p in the range of 2 to 12 bar, can be sealed off. Such oil pressures p can not be directly sealed in the rolling bearing 1 simple, known from the prior art, sealing elements, but require the rolling bearing 1 upstream seal.

In summary, it can be stated that an embodiment is provided by the proposed rolling bearing with an integrated pressure seal, which allows a seal also against the environment significantly increased operating pressures in a compact and inexpensive design. LIST OF REFERENCES

1 rolling bearing

2 outer ring

3 rolling elements

4 annular disc

5 sealing ring

6 oil

7 shoulder

8 chamfer

9 inner ring

10 groove

11 sealing space

12 first sealing gap

13 second sealing gap

14 groove base

15 recess

16 paragraph

17 bearing surface

18 stop surface

19 bevel

20 stop surface

a angle on the inner ring

ß angle on the sealing ring

DD diameter sealing ring

DN diameter groove bottom

Ds shoulder diameter

p oil pressure

Claims

claims

1. rolling bearing (1) having an inner ring (9) and an outer ring (2), wherein between the inner ring (9) and the outer ring (2) rolling elements (3) are arranged, and wherein between the outer ring (2) and the inner ring (9) is arranged at least on the pressure side of an annular disc (4), characterized in that the annular disc (4) in a recess (15) of the outer ring (2) or the inner ring (9) is received, and at a shoulder (16) is formed on the annular disc (4), onto which a closed sealing ring (5) is raised.

2. rolling bearing (1) according to claim 1, characterized in that on one of the rolling elements (3) facing side of the annular disc (4) hen a chamfer (8) is provided, which ends at the shoulder (16).

3. Rolling bearing (1) according to claim 1 or 2, characterized in that on the inner ring (9) of the rolling bearing (1) has a shoulder (7) is formed.

4. rolling bearing (1) according to claim 3, characterized in that between the annular disc (4) and the inner ring (9) a sealing gap (12) is formed, where at the sealing gap (12) in a first portion (12 a) parallel to a bearing surface (17) of the inner ring (9) and in a second portion (12b) at an angle a to the first portion (12a) extends.

5. Rolling bearing (1) according to claim 3 or 4, characterized in that on the sealing ring (5) on its shoulder (7) side facing a chamfer (19) is formed.

6. rolling bearing (1) according to claim 5, characterized in that the bevel (19) has an angle ß of 10 ° to 45 °.

7. rolling bearing (1) according to one of claims 1 to 6, characterized in that on the inner ring (9) has a groove (10) for releasing the sealing ring (5) is formed.

8. rolling bearing (1) according to one of claims 1 to 7, characterized in that on the inner ring (9) has a stop surface (18) is formed, wherein between the sealing ring (5) and the stop surface (18) of the inner ring ( 9), a second sealing gap (13) is formed.

9. rolling bearing (1) according to one of claims 1 to 8, characterized in that the sealing ring is made of a polyamide in the id material.

10. Rolling bearing (1) according to one of claims 1 to 9, characterized in that the shoulder (16) of the annular disc (4) and the groove (10) on the inner ring (9) are each wider than the sealing ring (5) in that the sealing ring (5) is displaceable in the axial direction between corresponding abutment surfaces (18, 20) on the inner ring (9) and on the annular disc (4).