DE102008042281A1 - Shaft bearing for use in worm gear of electric power steering system of motor vehicle, has holder connected with shaft, accommodating inner ring and comprising recesses enabling pivot movement towards section of holder - Google Patents

Abstract

The bearing (500) has a ball bearing (60) i.e. four point bearing, for storing a shaft (90) and comprising outer and inner rings (61, 62). The outer ring is supported in a housing section (20) of a steering system. The bearing has a holder (510) connected with the shaft, and the holder accommodates the inner ring. The holder has recesses enabling a pivot movement towards a section (512) of a holder. The holder has a disk-shaped section (511), and the recesses impair a transition region between the sections of the holder, so that the sections are flexibly moved against each other. An independent claim is also included for a method for manufacturing a holder for a shaft bearing in a steering system.

Description

The The invention relates to a shaft bearing in a steering system according to the preamble of claim 1 and a steering gear equipped therewith. In particular, the invention relates to the shaft bearing in one Steering gear as a helical gear for an electric Power steering system is formed. It also concerns the invention a method for producing a holder for such a shaft bearing.

From the DE 101 61 715 A1 is a generic shaft bearing within a Schraubradgetriebes known for use in an electric power steering system. The 1 shows the known Schraubradgetriebe 1 acting as a worm gear with a housing 2 is formed, in which a snail 3 and a worm wheel 4 are arranged, the snail 3 by means of a coupling 8th with the one in a warehouse 11 mounted drive shaft 9 an electric drive motor 10 connected is. In this known construction, the worm shaft is in a shaft bearing 5 stored, which is a ball bearing 6 has in the form of a four-point bearing and is designed as a self-aligning bearing, whereby the gear play between worm 3 and worm wheel 4 can be kept constant throughout the life of the transmission. This is the snail 3 acted upon radially with a biasing force and permanently against the teeth of the worm wheel 4 or helical wheel pressed. This is done by means of a biasing device, which is a biasing spring 13 and a printing device 12 has a play-free engagement between the screw 3 and the worm wheel 4 and to compensate for the operating forces occurring. The printing device 12 can z. B. with a hydraulic device 14 and a pressure piece actuated therefrom 15 Be provided on the local camp 16 or the snail 3 itself acts. Thus, the over the lifetime adjusting wear can be compensated automatically, so that the backlash is not possible enlarged and vibration noise can be avoided. However, it has been found in such a known construction that at the shaft bearing 5 Even noises can occur, which can only be eliminated by using an expensive special bearing.

It Other shaft bearings with ball bearings are known in which the outer ring of the ball bearing received in a plain bearing or in which the inner ring of the ball bearing in so-called. Silent bushes is received, whereby the shaft thus also mounted pivotally is. However, these solutions are expensive to implement and have a relatively large game, which in turn leads to noise especially during load changes (change axes) leads. In addition, these shaft bearings are vulnerable against temperature fluctuations and have no big Life on.

Of the The invention is therefore based on the object, the shaft bearing of the type mentioned to improve significantly. It should the mentioned disadvantages of conventional solutions be overcome in an advantageous manner. Also should a Method for producing a holder for such a shaft bearing be proposed.

Solved The task is achieved by a shaft bearing with the characteristics of Claim 1.

Therefore a shaft bearing is proposed with a ball bearing suggested the outer ring in a housing section is mounted of the steering system and the inner ring of a with the shaft connectable bracket is received, the bracket Has recesses that provide a movement at least for allow a section of the bracket that holds the inner ring of the Ball bearing receives.

According to the invention also a steering gear, in particular a Schraubradgetriebe proposed which is equipped with such a shaft bearing. Also will a steering system equipped therewith, in particular electric power steering system, proposed.

The provided in the holder recesses give this one definable elasticity, so that at least the section the bracket that receives the outer ring of the ball bearing, perform a movement, preferably a slight pivoting movement can.

proposed is also a process for producing a holder for Such a shaft bearing, wherein the holder of a disc-shaped Section part (eg made of spring steel sheet) is manufactured and from a cup-shaped section part (eg from soft sheet) produced by mutually forming and / or non-positively connected. It can z. B. in the disc-shaped section part openings be present, through which from one side material of the cup-shaped Section section and then pressed by the opposite side is reshaped, so that a positive connection and / or Tangle connects both sections together.

Preferably, the support is designed to have two different sections, the recesses weakening transition areas between the sections so that the sections are elastically movable relative to each other. In this case, the holder preferably has a disk-shaped Ab cut for attachment in the housing portion of the steering system and has a cup-shaped portion for receiving the outer ring of the ball bearing. In this context, it is advantageous if the recesses are formed in the disc-shaped portion as two opposing circular segment-shaped recesses, each enclosing a portion of the cup-shaped portion. In this case, the circular segment-shaped recesses may each enclose a region of the pot-shaped section to such an extent that two web-shaped transitional regions lying opposite one another remain in the disk-shaped section. In addition, the opposing ridge-shaped transitional areas may represent a semi-gimbal elastic connection between the sections.

Consequently becomes a definable material weakening between the disc-shaped or tab-shaped section and the pot-shaped portion provided, the ball bearing receives. There are two opposite transition areas formed like a half-gimbal's suspension cup-shaped section act, so that this elastic pivotally connected to the disc-shaped section is.

Preferably is at least the disc-shaped portion of the holder made of sheet metal, in particular of spring steel sheet. Furthermore preferably has at least the cup-shaped portion cylindrical, in particular formed of soft sheet, housing on, which encloses the outer ring of the ball bearing. The holder is preferably formed in several pieces and accordingly has at least one formed from spring steel sheet Section and has a formed from soft sheet metal section.

Consequently The disc-shaped portion is elastic by means of an elastic deformable material to an elastic disc or spring washer educated. The pot-shaped section, however, by means of a plastically deformable material to one for the ball bearing optimized receiving space formed.

Furthermore it is advantageous if on the housing portion of the steering system at least one elastic damping element is provided, against which the axially movable bracket strikes. Thereby is the storage of the spring washer in addition to axial Direction muffled.

The Holder can at its disc-shaped portion an opening with groove, fixed to the bracket and positioned with the Connect shaft.

Also the holder, in particular the cup-shaped section, be formed directly on the outer ring of the ball bearing. In addition, the ball bearing can be designed as a four-point bearing be.

These and further advantageous developments and refinements of Invention will become apparent from the dependent claims and from described below and schematically with reference to the drawing illustrated embodiments, wherein:

2 shows a cross-sectional view of a helical gear with inventive shaft bearing in a first embodiment;

3a -D show for the first embodiment different views of the provided in the shaft bearing holder (semi-gimbal variant);

4 illustrates the elastic mobility or pivotability of the holder;

5a -D show, for a second embodiment, different views of a holder provided in the shaft bearing (full cardan variant); and

6a -C show in detail different joining techniques for the production of the two-part holder.

The Embodiments illustrated in the figures show by way of example two preferred construction variants of inventively designed Shaft bearings, especially in a worm gear an electric power steering system trained Schraubradgetriebes can be used. The invention is not limited to helical gear in particular, but Can generally be applied to any type of steering gear.

The 2 shows the first embodiment of a shaft bearing according to the invention 500 in a helical gear designed as a worm gear 100 , One over a wave 90 with an electric drive motor (not shown) connectable screw 30 is in a housing section 20 , namely the transmission housing, arranged and is there with a worm wheel 40 engaged. To improve the engagement, a (not shown) biasing means is provided, which the screw 30 subjected to a biasing force and this radially (y-direction) against the worm wheel 40 suppressed.

The wave 90 the snail 30 is in the shaft bearing 500 stored, with the outer ring 61 of the ball bearing 60 from the housing section 20 is absorbed and the inner ring 62 in a holder 510 is taken up with the wave 90 connected is. The outer ring 61 and thus also the shaft bearing 500 are in the housing section 20 axially displaceable (x-direction) recorded. It can also be elastic damping elements 59 be provided for the axial movement (x-direction).

The holder 510 (see also 3a -D) is annular and has two sections 511 and 512 on. The one section 512 has a cup-shaped, in particular annular or cylindrical shape whose circumference of the inner ring 62 ball bearing 60 is completely enclosed. The other section 511 the holder 510 is disc-shaped and serves to attach the holder 510 on the shaft 90 , This happens z. B. in that the shaft 90 through a disk-shaped section 511 provided opening 515 plugged and then clamped during assembly.

How the particular 3a and 3b and 5a and 5b can show the bracket 510 be made in one piece from sheet metal, in particular from spring steel sheet, and the inner ring 62 fix free of play. The recesses 520 serve to provide relative movement between the disc-shaped section 511 (Spring washer) and the pot-shaped section 512 (Ring for the inner ring 62 ). In particular, both sections can entangle against each other in a defined direction (eg y-direction). The recesses 520 are z. B. as a circular segment-shaped cutouts in the spring washer 511 designed so that two opposite transition areas 530 or web-shaped transitions to the receiving housing 512 result. The recesses 520 have a defined opening angle α. The concomitant weakening of the material leads to a definable elasticity in the holder 510 so that the recording ring 512 opposite the spring washer 511 something can be swiveled.

This possibility of movement is in the 4 illustrates in the pivoting between the two sections 511 and 512 is represented by an angle β. The two bridges 530 (see also 3c ) form a semi-cardanic connection or suspension aligned along the z-axis. The pivoting direction is thus perpendicular to the shaft axis (x-direction) and goes in the radial direction (y-direction), whereby an elastically pivotable shaft bearing of the ball bearing or the worm shaft 90 is possible.

The ball bearing 60 (S. 2 ) is z. B. formed as a four-point bearing and is of the holder 500 fixed, which can preferably be moved axially in the x direction. As stop elements are on the housing portion 20 elastic damping elements (not shown) provided against which the axially movable outer ring 61 strikes. The fixation of the shaft 90 via the holder 510 , namely on the spring washer 511 which the recording ring 512 and thus the inner ring 62 of the ball bearing 60 gives an elastic about the y- and / or z-axis. At the spring washer 511 can be inside the opening 515 a nose 516 be provided to the spring washer and thus the entire holder 510 on the shaft 90 to position and fasten exactly.

The 3a -D show a construction for a resilient semi-cardanic bearing, with two opposing recesses 520 in the spring washer 511 a pivotable movement of the cup-shaped portion 512 opposite the spring washer 511 allow, namely a pivoting about the z-axis (see also pivot angle β in 4 ).

The 5a 3 show a construction for an elastic fully cardanic bearing, wherein two pairs of each two opposing recesses 521 respectively. 522 in the spring washer 511 provided are a pivotable full-cardanic movement of the cup-shaped portion 512 opposite the spring washer 511 enable. In this variant, therefore, the spring washer 511 four recesses, of which two recesses are located in the inner region of the spring washer and moved by 90 degrees, two more recesses are located in the outer region of the spring washer. This results in each case two opposing web-shaped transition areas 531 respectively. 532 , each representing a half-gimbal suspension (see. 3c ), so that thus results in a full-gimbal suspension. The construction shown here thus allows a pivoting movement in all directions from the center of the spring washer. In other words, the pivot axis can be arbitrarily in the plane of the spring washer (yz plane), where it passes through the center of the spring washer. This creates a full flexibility or elasticity of the shaft bearing.

How the particular 6a -C can illustrate the two sections 511 and 512 the holder 510 have different material properties. The disc-shaped section 511 (Spring washer) is preferably made of a spring steel sheet FB and the cup-shaped portion 512 made of deformable soft sheet WB. Both parts 511 and 512 can z. B. verclincht each other. One of the basis of the 6a C illustrated connecting techniques for producing a holder according to the invention may also consist in that for connecting the two parts 511 and 512 that he te section part 511 several openings 560 Has holes through which on one side material of the pot-like part 512 , which consists of soft sheet WB, is pressed and then pressed on the opposite side, z. B. is pressed into rivets, as shown by the 6b is illustrated. It can therefore be provided for the preparation of the holder described here, that openings in the first sheet FB 560 are present, is pressed by the one side material of the second sheet WB and then formed by the opposite side, so that a positive connection and / or adhesion both sections 511 . 512 connects with each other. It can be z. B. a closed rivet head or an open rivet head or rivets are formed.

The 6c shows in detail an alternative connection technology, in the first sheet also openings 560 are present, but then protruding areas of the pot-like section section 512 be plugged to be subsequently formed on the opposite side, so that also a positive connection and / or traction both sections 511 . 512 connects with each other.

at the production of such holders, especially when connecting the two section parts or halves can also be provided be that the two parts by means of clinching or Clinching or also be connected by means of punch rivets. In addition, can be provided that the two section parts also with additional rivets and / or with additional Screws are connected.

By the constructions and manufacturing steps described here become at least a half-gimbal connection in the holder for the Ball bearings and the worm shaft scored to the intervention of snail and worm wheel elastically pivotable to design. This can not be done only rattling and vibration noise, but also a Warping or jamming of the worm gear by one to large expansion of certain materials reliably be avoided. It is thus advantageously a play-free elastic Gear engagement of the worm gear achieved.

Also If the invention by way of example on a trained as a worm gear Schraubradgetriebe has been described, so is the invention not limited to helical gear, but can be general be applied to any type of steering gear. The embodiments shown are particularly suitable for use in an electric power steering system suitable for motor vehicles.

1

conventional Schraubradgetriebe in the form of a worm gear u. a. With:

2

Casing,

3

Slug,

4

worm

5

Shaft bearing and screw or fixing ring 7 *

500

first Embodiment of an inventive Shaft bearing u. a. With:

510

Holder (one-piece, half-gimbal solution) with: disk-shaped section 511 (Spring washer) and pot-shaped section 512

520

recesses (circular segment, opening angle α)

530

Transition areas (remaining connecting bridges)

515

Opening for attaching the holder to the shaft 90

516

nose for positioning

60

Ball-bearing, esp. four-point camp

61

outer ring

62

inner ring

β

Entanglement angle (by elastic displacement of the sections 511 and 512 )

100

helical gears, in the form of a worm gear, u. a. With:

20

casing or housing section of the steering system

30

slug

40

worm

90

worm shaft

500

shaft bearing gem. first embodiment

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 10161715 A1 [0002]

Claims (28)

Shaft bearing ( 500 ) in a steering system used to support a shaft ( 90 ) a ball bearing ( 60 ) with an outer ring ( 61 ) and with an inner ring ( 62 ), wherein the outer ring ( 61 ) in a housing section ( 20 ) of the steering system, characterized in that the shaft bearing ( 500 ) one with the shaft ( 90 ) connectable bracket ( 510 ) having the inner ring ( 62 ) of the ball bearing ( 60 ), wherein the holder ( 510 ) Recesses ( 520 ) having a movement (β) for at least a portion ( 512 ) of the holder ( 510 ), the inner ring ( 62 ) of the ball bearing ( 60 ). Shaft bearing ( 500 ) according to claim 1, characterized in that the holder ( 510 ) two sections ( 511 . 512 ), wherein the recesses ( 520 ) Transition areas ( 530 ) weaken between the sections so that the sections ( 511 . 512 ) are elastically movable against each other (β). Shaft bearing ( 500 ) according to claim 1 or 2, characterized in that the holder ( 510 ) a disk-shaped section ( 511 ) with an opening ( 515 ) for attachment, in particular for attachment, the holder ( 510 ) on the shaft ( 90 ) and a cup-shaped section ( 512 ), on whose outer circumference the inner ring ( 62 ) of the ball bearing ( 60 ) is arranged. Shaft bearing ( 500 ) according to claim 3, characterized in that the recesses in the disc-shaped portion ( 511 ) as two opposite circular segment-shaped recesses ( 520 ) are formed, each having a portion (α) of the pot-shaped portion ( 512 ) enclose. Shaft bearing ( 500 ) according to claim 4, characterized in that the circular segment-shaped recesses ( 520 ) each have a portion of the pot-shaped portion ( 512 ) so far as (α) that in the disk-shaped section ( 511 ) two opposing web-shaped transition regions ( 530 ) remain. Shaft bearing ( 500 ) according to claim 5, characterized in that the opposing web-shaped transition regions ( 530 ) a half-cardan elastic connection between the sections ( 511 . 512 ). Shaft bearing ( 500 ) according to claim 6, characterized in that in the disc-shaped portion of the holder ( 510 ) in addition to the recesses ( 521 ) even more recesses ( 522 ) are provided, which are radially offset, so that to the opposite web-shaped transition regions ( 531 ) further web-shaped transition regions ( 532 ), which together constitute a fully gimbal elastic connection between the disc-shaped portion and the pot-shaped portion. Shaft bearing ( 500 ) according to one of claims 3 to 7, characterized in that at least disc-shaped section ( 511 ) of the holder ( 510 ) is made of sheet metal, in particular of spring steel sheet. Shaft bearing ( 500 ) according to any one of claims 3 to 7, characterized in that at least the pot-shaped portion ( 512 ) has a cylindrical, in particular made of soft sheet, housing, which the inner ring ( 62 ) of the ball bearing ( 60 ). Shaft bearing according to one of the preceding claims, characterized in that the holder ( 510 ) is formed in several pieces and at least one formed from spring steel sheet section ( 511 ) and a molded from soft sheet section ( 512 ) having. Shaft bearing ( 500 ) according to one of the preceding claims, characterized in that on the housing section ( 20 ) of the steering system, at least one elastic damping element is provided, against which the axially movable support ( 510 ) strikes. Shaft bearing according to one of the preceding claims, characterized in that the disc-shaped portion ( 511 ) into a nose ( 516 ) for positioning on the shaft ( 90 ) having. Shaft bearing according to one of the preceding claims, characterized in that the holder ( 510 ), in particular the pot-shaped section ( 512 ), directly on the inner ring ( 62 ) of the ball bearing ( 60 ) is trained. Shaft bearing according to one of the preceding claims, characterized in that the ball bearing as a four-point bearing ( 60 ) is trained. Steering gear ( 100 ) with a shaft bearing ( 500 ) used to support a shaft ( 90 ) a ball bearing ( 60 ) with an outer ring ( 61 ) and with an inner ring ( 62 ), wherein the outer ring ( 61 ) in a housing section ( 20 ) of the steering system, characterized in that the shaft bearing ( 500 ) one with the shaft ( 90 ) connectable bracket ( 510 ) having the inner ring ( 62 ) of the ball bearing ( 60 ), wherein the holder ( 510 ) Recesses ( 520 ) having a movement (β) at least for one section ( 512 ) of the holder ( 510 ), the inner ring ( 62 ) of the ball bearing ( 60 ). Steering gear ( 100 ) according to claim 15, characterized in that the steering gear is a helical gear ( 100 ) is that one over the shaft ( 90 ) connectable with an electric drive motor screw pinion ( 30 ), which in the housing section ( 20 ) of the steering system is arranged and with a helical gear ( 40 ) is engaged. Helical gear ( 100 ) according to claim 16, characterized in that the Schraubradgetriebe as worm gear ( 100 ), wherein the helical gear as worm wheel ( 40 ) is formed and the screw pinion as a screw ( 30 ) is formed, which with the worm wheel ( 40 ) is engaged. Steering system with a shaft bearing ( 500 ) used to support a shaft ( 90 ) a ball bearing ( 60 ) with an outer ring ( 61 ) and an inner ring ( 62 ), wherein the outer ring ( 61 ) in a housing section ( 20 ) of the steering system, characterized in that the shaft bearing ( 500 ) one with the shaft ( 90 ) connectable bracket ( 510 ) having the inner ring ( 62 ) of the ball bearing ( 60 ), wherein the holder ( 510 ) Recesses ( 520 ) having a movement (β) for at least a portion ( 512 ) of the holder ( 510 ), the inner ring ( 62 ) of the ball bearing ( 60 ). Steering system according to claim 18, characterized in that the steering system is a steering gear, in particular a helical gear ( 100 ), having. Steering system according to claim 19, characterized that the steering system is designed as an electric power steering system is. Method for producing a holder ( 510 ) for a shaft bearing ( 500 ) in a steering system used to support a shaft ( 90 ) a ball bearing ( 60 ) with an outer ring ( 61 ) and with an inner ring ( 62 ), wherein the outer ring ( 61 ) in a housing section ( 20 ) of the steering system, characterized in that the holder ( 510 ) for attachment to the shaft ( 90 ) is made, so that the holder ( 510 ) the inner ring ( 62 ) of the ball bearing ( 60 ) and recesses ( 520 ) having a movement (β) for at least a portion ( 512 ) of the holder ( 510 ), the inner ring ( 62 ) of the ball bearing ( 60 ), wherein the holder ( 510 ) from a disk-shaped section part ( 511 ) is produced from a first metal sheet (FB), in particular spring steel sheet, and from a pot-shaped section part ( 512 ) is produced from a second sheet (WB), in particular soft sheet, by 511 . 512 ) are positively and / or non-positively connected. Method for producing a holder ( 510 ) according to claim 21, characterized in that in the first sheet (FB) openings ( 560 ) are present, is pressed by the one side of the material of the second sheet (WB) and then formed by the opposite side, so that a positive connection and / or frictional connection both sections ( 511 . 512 ) connects to each other. Method for producing a holder ( 510 ) according to claim 21, characterized in that in the first sheet (FB) openings ( 560 ) are provided by the projecting portions of the cup-like section portion ( 512 ) are inserted and then be transformed by the opposite side, so that a positive connection and / or traction both sections ( 511 . 512 ) connects to each other. Method for producing a holder ( 510 ) according to claim 22 or 23, characterized in that in each case a closed rivet head or an open rivet head or hollow rivets is formed on the opposite side during the deformation of the material or the protruding areas. Method for producing a holder ( 510 ) according to claim 21, characterized in that the two section parts ( 511 . 512 ) are connected by clinching or clinching. Method for producing a holder ( 510 ) according to claim 21, characterized in that the two section parts ( 511 . 512 ) are connected by means of punch rivets Method for producing a holder ( 510 ) according to one of claims 22 to 26, characterized in that the two section parts ( 511 . 512 ) can also be connected with additional rivets Method for producing a holder ( 510 ) according to one of claims 22 to 26, characterized in that the two section parts ( 511 . 512 ) can also be connected with additional screws