DE102020121188A1 - Bearing with a sensor system and method for producing a bearing - Google Patents

Abstract

The invention relates to a bearing (1) with at least one first bearing ring (3) and at least one second bearing ring (4) and with a sensor (2), the sensor (2) consisting of at least one axis of rotation (6) of the bearing ( 1) rotatably arranged in the bearing (1) rotor (7) and is formed from at least one stator (8) interacting with the rotor (7) and from a stationary stator housing (5) at least partially accommodating the stator (8), and wherein the stator (8) is accommodated in the stator housing (5) and at least partially embedded in a casting compound (9), the stator housing (5), which is designed separately from the bearing rings (4, 5), being connected to one of the bearing rings (4, 5). is.

Description

field of invention

The invention relates to a bearing with at least one first bearing ring and at least one second bearing ring and with a sensor system, wherein the sensor system consists of at least one runner arranged in the bearing so that it can rotate about an axis of rotation of the bearing and of at least one stator that interacts with the runner and of a den Stator is formed at least partially dwelling stationary stator housing, and wherein the stator is accommodated in the stator housing and at least partially embedded in a casting compound, wherein the stator housing, which is formed separately from the bearing rings, is connected to one of the bearing rings. The invention also relates to a method for producing or assembling such a bearing.

Background of the Invention

In WO19063095 A1 discloses a roller bearing with a sensor system, in which the stator of the sensor system is accommodated in an axial extension of the outer ring that is configured in one piece with the outer ring of the roller bearing.

DE 10 2018 131 254 A1 discloses a roller bearing with a sensor system, on which the stator of the sensor system is accommodated in a stator housing that is separate from the outer ring of the roller bearing. The stator housing is a sleeve-shaped component made of sheet metal, in which the stationary part of the sensor system is permanently held by means of a casting compound. The stator housing is placed on the outer ring.

Description of the invention

The object of the invention is to create a bearing of the type that can be produced easily and inexpensively as well as reliably and to create a method for assembly that is reliable.

The object is achieved according to the subject matter of claim 1 according to the invention.

It is provided that a casting compound carrier which is separate from the casting compound and is integrally connected to the stator housing is accommodated in the stator housing. The potting compound carrier is at least partially filled with the potting compound. The stator is non-detachably held in the casting compound carrier by means of the casting compound.

The bearing has at least one inner and one outer bearing ring and is provided with a sensor system. Bearings within the meaning of the invention are machine elements with which shafts or axles or similar technical structures are mounted such that they can rotate relative to one another or relative to a stationary housing so that they can rotate about their axis of rotation. The bearing within the meaning of the invention is preferably a roller bearing. The roller bearing has bearing rings, ie at least one inner ring and one outer ring, which does not rule out the possibility of having a number of inner and outer rings. At least one row of rolling bodies, for example balls, cylindrical rollers or tapered rollers, which are adjacent to one another in the circumferential direction are arranged between the inner ring and the outer ring. It is also conceivable that the roller bearing has a plurality of rows of roller bodies arranged axially next to one another. The rolling bodies run on rolling raceways, which are formed on the bearing rings. As a rule, the rolling bodies are held and guided in a cage or cages. In general, it is defined within the meaning of the invention that the axis of rotation runs axially. The axis of rotation can run obliquely or transversely in any direction in space. Radial is transverse, i. H. aligned perpendicular to the axis of rotation.

The sensor system is formed at least from a rotor, a stator, a stator housing, a potting compound carrier and the potting compound. Optionally, connecting lines or seals are also assigned to the sensor system.

A part of a device or machine that rotates around an axis of rotation is referred to as a runner or rotor. In connection with the invention, the runner consists of one component or of several components or of an assembly of the sensor system, which or which with one of the bearing rings or with a shaft on which the bearing ring is seated, designed to be rotatable about the axis of rotation of the bearing is or are. The runner is, for example, a signal transmitter in the form of an impulse ring.

The term “stator” is generally understood to mean the fixed, immovable part of a device or a device, particularly when it interacts with a rotor or runner. In connection with the invention, the stator is a preferably electronic component or a preferably electrical-electronic assembly of the sensor system. The stator is, for example, the receiver (sensor) assigned to the signal transmitter (rotor). In addition, the term stator optionally also includes supply connections and connecting elements, such as connecting lines formed from cables or conductor tracks. Connection elements are used to connect the Sen sorik provided with the environment or other components or assemblies.

Connections can be made, for example, without cables (antennas or other transmission devices) or with cables to supply and/or evaluation units. According to the invention, the stator includes the components of the sensor system, which are arranged stationary on one of the bearing rings in/on the bearing and are accommodated in the stator housing or potting compound carrier.

First of all, the stator is assigned to the sealing compound carrier in a stationary manner, because the stator is held firmly in the sealing compound carrier by means of the sealing compound. The potting compound carrier is also assigned to the stator housing in a stationary manner because it is immovably fixed to the stator housing by means of a material connection. The stator housing is stationary relative to one of the bearing rings, preferably the outer ring, because it is firmly seated on one of the bearing rings, preferably on the outer ring. The bearing ring is fixed either to a shaft or shaft-like component or to a housing or housing-like component because it is firmly seated in the component. Shafts and housings are, for example, gears, journals or other machine elements or assemblies that are to be rotatably mounted or serve as bearing housings. Shafts or shaft-like components or housings or housing-like components are stationary on the vehicle, but alternatively also movably, for example rotating, relative to another housing or the vehicle.

The stator housing is preferably formed from sheet metal and has a hollow-cylindrical base body. The base body has different diameter levels or is designed to be uniform in diameter. The potting compound carrier is a hollow component, the hollow-cylindrical shell of which has different diameter steps or is designed to be uniform in diameter and whose bottom is provided with a central through-hole. The material of the casting compound carrier is plastic, but alternatively it can also be sheet metal.

In the prior art described at the beginning and already known before the time of the invention, the stator or the components of the stator are seated in the stator housing. The casting compound is filled directly into the stator housing. Alternatively, a sheet metal sleeve is provided with the stator embedded in a casting compound, which is mechanically positively secured, for example by snapping. The cost of manufacturing and assembling such devices according to the prior art is relatively expensive. The designs of the casting compound carrier are very filigree and therefore difficult to handle both in production and during assembly, especially with regard to roller bearings of the small diameter series. In contrast to this, the stator or the components of the stator are inserted into the potting compound carrier according to the invention and embedded in the potting compound introduced into the potting compound carrier. The potting compound carrier is connected to the stator housing in a form-fitting manner when it is manufactured. The invention has both functional and technological advantages and ensures improved quality over the prior art. There is no need for time-consuming individual production and assembly. The design according to the invention enables absolute tightness when casting. The liquid casting compound remains within the intended filling space when the casting compound carrier is filled and is not lost through possible leaks. A preassembled unit according to the invention, formed from the stator housing, the casting compound carrier, the stator, the casting compound and, if applicable, the connecting elements, can be easily and inexpensively replaced with existing prior-art assemblies, and these can be exchanged without changing the connection dimensions and while retaining the same roller bearing.

At least integrally connected is to be understood as meaning that the stator housing and the casting compound carrier are in any case integrally connected to one another and, moreover, can optionally also be connected to one another by a form fit or form fits.

Potting compound is to be understood as meaning a compound that is initially liquid or plastic during its processing, which is rigidly or elastically hardened in its final state, and in which components and assemblies of the stator are at least partially or completely embedded or cast. In this case, the component, for example a sensor, or the assemblies, for example printed circuit boards, are partially or completely enclosed and encased with the casting compound. The potting compound is intended to fix the stator in the potting compound carrier or to protect the components and assemblies of the stator.

Casting compounds are casting resins or adhesives or other suitable binding or protective agents, which are generally summarized below under the term synthetic resins. These synthetic resins are mixed from one or more components and are processed in liquid form and then solidify. They then have more or less hard or elastic properties. Examples of casting compound materials are polyester resins, polyurethanes, epoxy resins, silicone resins, vinyl ester resins, phenolic resins or acrylic resins. the Potting compound is also optionally infused with fillers and colorants.

According to the invention, the casting compound carrier is optionally connected to the stator housing in a materially and/or form-fitting manner by injection molding, vulcanizing or gluing or casting. In general, it is also conceivable to connect a casting compound carrier made of metal to a metal stator housing, e.g. by welding, in a metal-to-material manner. The potting compound cast or pressed in the potting compound carrier is in turn connected to the potting compound carrier in a materially and/or form-fitting manner. The components or assemblies of the stator are embedded in the casting compound and are partially or completely surrounded by it.

Cohesive connections of the potting compound with the potting compound carrier are understood to mean adhesively bonded connections which are created by the effects of atomic or molecular connections in the sense of cohesion and/or adhesion.

The cohesion and adhesion properties of the synthetic resin and the stator housing or potting compound carrier determine the properties of the material connections. Cohesive forces define how atoms and molecules of the same kind are held together. Adhesive forces cause atoms or molecules of different kinds to be held together.

The adhesion of the synthetic resins to the stator housing or casting compound carrier is determined by the adhesive properties. Adhesion describes the physical state of interface layers that are formed between the elements that are connected to one another in a materially bonded manner in this way. They therefore stand for the mechanical and/or mechanical-chemical cohesion that is formed by molecular interactions in the interface layer between the elements, in this case between those of the potting compound and those of the potting compound carrier. On the one hand, there are mechanical form-fit anchorings of the synthetic resins in the boundary layer in the microscopically small pores and depressions on the surface of the component, for example on the surface of the stator housing or on the surface of the casting compound carrier. This applies to the stator housing if the casting compound carrier is glued or cast into the stator housing. Liquid or paste-like synthetic resins can also penetrate into undercuts with a positive fit during processing, so that after the synthetic resins have hardened, purely mechanical positive locking also occurs, which gives the connection additional support.

On the other hand, when plastics and synthetic resins are glued, sprayed on and potted, diffusion processes can occur in the boundary layer if the plastics contain solvents, for example. The surface is partially dissolved by the solvent. This leads to an interpenetration, for example, of the polymer chains of the component with those of the synthetic resin on the surface. The aforementioned mechanical-chemical bonds are therefore also possible during casting. This applies to both components in the specific case, in particular when the stator housing and/or the casting compound carrier are made of plastic(s). Alternatively, this also applies to bonds between a component and the synthetic resin if the component, such as the potting compound carrier, is made of plastic.

The mechanical properties of the connection are determined by the cohesion properties. With increasing hardening of the synthetic resins, their internal strength and cohesion increase. Ultimately, these properties also determine the elasticity and strength of the connection or the casting compound and, together with the properties of the material, also define properties such as the ability to insulate against temperature and electrical current or the dielectric strength against electrical voltages.

One embodiment of the invention provides that the potting compound carrier is formed from at least one plastic. Alternatively, the casting compound carrier is also formed or composed of more than one plastic and optionally also contains additives, fillers made of a wide variety of materials. The advantage of the invention lies in the fact that such a casting compound carrier can be produced simply and inexpensively. In addition, such casting compound supports can also be attached to the stator housing at low cost, preferably by injection molding using a plastic injection molding process.

One embodiment of the invention provides that the stator housing consists of a metal or a metal alloy. The stator housing is preferably a sheet metal component made from cold-formed sheet steel or from a tube. The advantage of the invention lies in the fact that components of this type can be produced easily and inexpensively, in particular in mass production. The tool costs are low.

A further embodiment of the invention provides that the stator, as already mentioned at the beginning, has at least one at least part wise is provided by the potting compound held connecting line. It is provided that at least part of the connecting line(s) is passed through a recess in the stator housing. It is also conceivable that the potting compound carrier has a recess or that both the stator housing and the potting compound carrier have a recess. The recess is made in the edge or in the bottom of the respective carrier and serves as a passage for the cables of the connecting lines. The recesses are preferably formed radially continuously in a radial lateral surface of the carrier and in this way advantageously allow the connecting lines to be routed briefly and stably on the bearing. Additional holding elements, which are integrally formed on the sheet metal of the stator housing and hold the connecting lines, can prevent the connecting lines from breaking off or tearing off during transport, during assembly of the bearing in the bearing point and also during operation of the bearing in the installed state. The sensor is connected to the connecting lines, ie the connecting lines are connected to the sensor. This means that both the sensor placed in the casting compound and at least the connection area of the connecting lines are embedded in the casting compound.

A further embodiment of the invention provides that the casting compound carrier is an annular component rotating around the axis of rotation of the bearing. This component has an axially aligned first hollow cylinder section and a second hollow cylinder section that runs concentrically at a radial distance from the first hollow cylinder section and is also axially aligned, as well as a radial ring disk section that connects the hollow cylinder sections to one another and runs around the axis of rotation and is radially aligned at the same time. Axially aligned is aligned with the axis of rotation. The preferred shape of this casting compound carrier is therefore similar to a double-walled hollow cylinder which has a base at one end, ie is closed there. The advantage of the invention results from the fact that this casting compound carrier is closed radially in two directions and axially in one direction. It forms an ideal closed mold. For this reason, the potting compound cannot naturally be lost when the potting compound carrier is filled. In contrast, with the previously known state of the art, special attention must be paid to the tightness of the casting or injection molding tools between the individual molds and slides. This has a negative effect on tool costs.

The casting compound carrier forms a housing that is closed on three sides, in which the stator, connecting lines and the casting compound itself are protected against chemical and mechanical influences on three sides by the walls of the casting compound carrier. The open side of the potting compound carrier is directed in the direction of the rolling elements and the disc-shaped section of the potting compound on this side is therefore in an already protected area. Up to the time when the invention was made, the casting compound had to have a high level of strength, since it had an essential load-bearing function. In addition, it had to be resistant to mechanical and chemical loads because it was directly exposed to these influences. The material of the casting compound itself in the bearing according to the invention no longer has to have the high strength and durability compared to the known prior art, because the supporting function and the function of a protective cover are taken over by the casting compound carrier. On the one hand, the designer has more options when choosing the material of the sealing compound with regard to the processing and the chemical and mechanical properties of the sealing compound and, on the other hand, a more cost-effective material can also be selected for the sealing compound under certain circumstances.

At least one of the hollow cylinder sections, preferably the radially outer one, is provided with one of the above-mentioned recesses for passing through connections, which can be introduced cost-neutrally when molded onto the stator housing and offers advantages in fixing and aligning connecting lines. This recess can also be formed on a section of the hollow cylinder which extends axially beyond the body of the hollow cylinder.

The invention also provides a method for manufacturing or assembling such a bearing. According to this, it is provided that first a stator housing is preferably formed from sheet metal or is cut from a tube. The casting compound carrier is then sprayed onto the stator housing in a plastic injection molding process. The slave and other assemblies of the stator, such as energy stores and components for evaluating signals from the rotor, are then inserted into the potting compound carrier and positioned there as intended. The potting compound is then introduced into the potting compound carrier by casting, spraying or filling, and the stator is at least partially embedded or completely encased by the potting compound. Following this, the casting compound carrier is attached to one of the bearing rings, preferably way pressed into or pressed onto this. The arrangement according to the invention can be produced simply and inexpensively by such a method.

Description of the drawings

4 4 shows a bearing 20 of the prior art in a longitudinal section along its axis of rotation 6, as this already from DE 10 2018 131 254 A1 is known. The bearing 20 is a roller bearing with a first bearing ring 3 designed as an outer ring and a second bearing ring 4 designed as an inner ring. The rolling bodies 12 are designed as balls and are guided in a cage 19 . A seal 21 is seated on the left and right of the rolling elements 12 . The sensor system 22 of the bearing 1 has a rotor 7 , a stator 23 and a stator housing 24 . The stator 23 is seated in a radially guided manner in the stator housing 24 and is centered on the axis of rotation 6 . The sections 25a, 25b and 25c completely embed the stator 23 in a radial direction and axially in both directions. The end face of the stator 23 is covered in one axial direction opposite the rotor 7 by a radial disc-shaped section 25a of the casting compound 25, in the direction of the axis of rotation 6 by a hollow-cylindrical section 25b and at the end face in the other axial direction by a section 25c of the casting compound 25 covered. The connecting lines 13 leading to the stator 23 are held by the potting compound 25 in the region of their connection to the sensor system 22 at section 25c. In this arrangement, the casting compound 25 generally also assumes a supporting and chemically or mechanically protective function for the stator 23 in a radial direction and in both axial directions. The material for the casting compound 25 must have correspondingly good strength properties and chemical resistance.

1 and 2 In 1 an exemplary embodiment of an assembly 26 according to the invention is shown with the pictorial representation of a section. 2 shows a pictorial half of the same assembly 26. The assembly 26 is formed from a stator housing 5, a stator 8, a potting compound carrier 10, a potting compound 9 and connecting lines 27 and can optionally without changing the connection dimensions on an outer ring with 4 roller bearing shown or mounted on any other bearing rings of roller bearings, not shown.

1 The stator housing 5 has a hollow-cylindrical section 5a with a larger diameter and a hollow-cylindrical section 5b with a smaller diameter. The casting compound carrier 10 is provided with a radially inner hollow cylinder section 15 and with a radially outer hollow cylinder section 16 as well as with an annular disk section 17 formed on the front side, with a closed radial connection between the radially inner hollow cylinder section 15 and the radially outer hollow cylinder section 16 is formed. The stator housing 5 and the potting compound carrier 10 are positively connected to one another via their sections 5a and 16 in such a way that the potting compound carrier 10 is molded onto the stator housing 5 in a plastic injection molding process.

The stator 8 sits in the casting compound carrier 10. The casting compound 9 made of a synthetic resin is cast in the casting compound carrier 10 and the stator 8 is thereby complete and the connecting lines 27 are embedded in the casting compound 9 at the ends. The hold of the connecting lines 27 on the assembly 26 is additionally reinforced by the hold in radial recesses 18 which are formed in the casting compound carrier 10 and in which the connecting lines 27 are clamped.

1 and 2 The stator housing 5 is provided with a radial recess 11 through which the connecting lines 27 are passed radially. During the production of the stator housing 5, the recess 11 was cut out in such a way that a tab 28 formed in one piece with the hollow-cylindrical section 5a was bent protruding radially outwards from the waste produced. This tab 28 is used, for example, as an alignment aid for positional orientation during assembly of the bearing.

3 According to a method according to the invention, the stator housing 5 is first produced and then the casting compound carrier 10 is injection molded onto the stator housing 5 . The electronics of the stator 8 are then positioned in the potting compound carrier 10 in an intermediate step. 3 shows the result of this intermediate step. The composite of the stator housing 5 and the potting compound carrier 10 is shown before the potting, in which the stator 8 is positioned. The connecting lines 27 are clamped in the respective recess 18, laid through the recess 11 and thus brought into their intended position.

Reference List

1

warehouse

2

sensors

3

first bearing ring

4

second bearing ring

5

stator housing

5a

hollow cylindrical section of larger diameter

5b

hollow cylindrical section of smaller diameter

6

Axis of rotation of the bearing

7

runner

8th

stator

9

potting compound

10

potting compound carrier

11

recess

12

rolling elements

13

connection line

14

not forgiven

15

first hollow cylinder section

16

second hollow cylinder section

17

washer section

18

recess

19

Cage

20

warehouse

21

poetry

22

sensors

23

stator

24

stator housing

25

potting compound

25a

Section of potting compound

25b

Section of potting compound

25c

Section of potting compound

26

module

27

connection lines

28

tab

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 19063095 A1 [0002]
• DE 102018131254 A1 [0003, 0031]

Claims (8)

Bearing (1) with at least one first bearing ring (3) and at least one second bearing ring (4) and with a sensor (2), wherein the sensor (2) consists of at least one rotatable about an axis of rotation (6) of the bearing (1) in The rotor (7) arranged on the bearing (1) and is formed from at least one stator (8) interacting with the rotor (7) and from a stationary stator housing (5) at least partially accommodating the stator (8), and the stator (8 ) is accommodated in the stator housing (5) and at least partially embedded in a casting compound (9), the stator housing (5), which is designed separately from the bearing rings (4, 5), being connected to one of the bearing rings (4, 5), characterized in that that in the stator housing (5) there is a potting compound carrier (10) which is materially connected to the stator housing (5) and to the stator housing (5) and which is at least partially filled with the potting compound (9), the stator (8) being the potting compound (9) in the potting mass carrier (10) is held inextricably. Bearing (1) after claim 1 , characterized in that the casting compound carrier (10) is formed from at least one plastic. stock after claim 1 or 2 , characterized in that the stator housing (5) is made of at least one metal material or a metal alloy. stock after claim 1 , characterized in that the stator (8) is provided with at least one connecting line (27) held at least partially by the casting compound (9), at least part of the connecting line (27) passing through a first recess (11) in the stator housing (5) is passed through. stock after claim 1 or 4 , characterized in that a first bearing ring (3) of the bearing rings (3, 4) is an outer ring of the bearing (1) designed as a roller bearing, the roller bearing having at least the outer ring and a second bearing ring (4), designed as an inner ring, of the bearing rings (3 , 4) and rolling elements (12) arranged radially between the bearing rings (3, 4), and wherein the stator housing (5) and the outer ring are connected to one another, radial being defined as transverse to an axially aligned axis of rotation (6). stock after claim 1 or 2 , characterized in that the potting compound carrier (10) is an annular component rotating about an axially aligned axis of rotation (6) of the bearing (1) with an axially aligned first hollow cylinder section (15) and one running at a radial distance from the first hollow cylinder section (15). and axially aligned second hollow cylinder section (16) and with a radial annular disk section (17) connecting the hollow cylinder sections (15, 16) to one another and running around the axis of rotation (6), radial being defined as transverse to the axis of rotation (6). stock after claim 1 or 2 , characterized in that the potting compound carrier (10) is an annular component rotating about an axially aligned axis of rotation (6) of the bearing (1) with an axially aligned first hollow cylinder section (15) and one running at a radial distance from the first hollow cylinder section (15). and axially aligned second hollow cylinder section (16) and with a radial annular disk section (17) connecting the hollow cylinder sections (15, 16) to one another and running around the axis of rotation (6), radial being defined as transverse to the axis of rotation (6), and wherein at least one of the sections (15, 16, 17) is provided with a second recess (18), a connecting line (13) held by the casting compound (9) passing through the second line formed in one of the sections (15, 16, 17). Recess (18) is passed through. A method of manufacturing a bearing (1). claim 1 , characterized by the following steps: - providing a stator housing (5), - molding a casting compound carrier (10) onto the stator housing (5) by a plastic injection molding process, - inserting the stator (8) into the casting compound carrier (10), - introducing the casting compound (9) and at the same time at least partially embedding the stator (8) in the casting compound (9), - providing a bearing (1) designed as a roller bearing with the rotor (7), - connecting the stator housing (5) with a bearing ring (4 ) of the bearing rings (4, 5).

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