U.S. patent application number 10/473265 was filed with the patent office on 2004-05-20 for threaded mechanism with rolling bodies and drive device of an automotive axle guide module.
Invention is credited to Bayer, Ronald, Hoffmann, Oliver, Jungbecker, Johann, Krauss, Manfred, Linkenbach, Steffen, Nell, Joachim, Neuwirth, Ernst, Osterlanger, Jurgen, Rath, Thomas, Schack, Peter.
Application Number | 20040095016 10/473265 |
Document ID | / |
Family ID | 7679402 |
Filed Date | 2004-05-20 |
United States Patent
Application |
20040095016 |
Kind Code |
A1 |
Bayer, Ronald ; et
al. |
May 20, 2004 |
Threaded mechanism with rolling bodies and drive device of an
automotive axle guide module
Abstract
In a threaded mechanism with rolling bodies comprising a spindle
rod, a spindle nut at least partially enclosing said spindle rod,
and a number of interposed rolling bodies, an axial and radial
mounting support is provided for the spindle nut that is adapted to
receive both tilting movements of the spindle nut about its
longitudinal axis as well as radial movements transversely to its
longitudinal axis.
Inventors: |
Bayer, Ronald;
(Mulheim/Main, DE) ; Schack, Peter; (Seligenstadt,
DE) ; Jungbecker, Johann; (Badenheim, DE) ;
Linkenbach, Steffen; (Eschborn, DE) ; Hoffmann,
Oliver; (Frankfurt am Main, DE) ; Nell, Joachim;
(Hanau, DE) ; Rath, Thomas; (Dietzenbach, DE)
; Neuwirth, Ernst; (Herzogenaurach, DE) ; Krauss,
Manfred; (Herzogenaurach, DE) ; Osterlanger,
Jurgen; (Emskirchen, DE) |
Correspondence
Address: |
RADER, FISHMAN & GRAUER PLLC
39533 WOODWARD AVENUE
SUITE 140
BLOOMFIELD HILLS
MI
48304-0610
US
|
Family ID: |
7679402 |
Appl. No.: |
10/473265 |
Filed: |
September 26, 2003 |
PCT Filed: |
March 28, 2002 |
PCT NO: |
PCT/EP02/03536 |
Current U.S.
Class: |
301/124.1 |
Current CPC
Class: |
F16H 2025/2445 20130101;
B62D 5/0424 20130101; B62D 5/0448 20130101; F16H 25/24
20130101 |
Class at
Publication: |
301/124.1 |
International
Class: |
B60B 035/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 28, 2001 |
DE |
101-15-316.3 |
Claims
1. Threaded mechanism with rolling bodies comprising a spindle rod
(1), a spindle nut (4) at least partially enclosing said spindle
rod, and a number of interposed rolling bodies (3), characterized
in that there is provision of an axial and radial mounting support
for the spindle nut (4) that is so designed as to allow both
tilting movements of the spindle nut (4) about its longitudinal
axis and radial movements transversely relative to its longitudinal
axis.
2. Threaded mechanism with rolling bodies as claimed in claim 1,
characterized in that at least one axial roller bearing (6) is
provided for the axial mounting support of the spindle nut (4)
having a radial flange (7), the frontal ends of which are designed
as an abutment for the axial roller bearing (6).
3. Threaded mechanism with rolling bodies as claimed in claim 1 or
2, characterized in that the axial mounting support is provided on
a housing (8) that is designed on facing frontal ends as an
abutment for the axial roller bearing (6).
4. Threaded mechanism with rolling bodies as claimed in claim 3,
characterized in that the housing (8) includes two housing shells
(8) divided transversely relative to the axis of rotation of the
spindle rod (1), and each one axial roller bearing (6) is
interposed between the radial flange (7) and each of the housing
shells (8).
5. Threaded mechanism with rolling bodies as claimed in claim 4,
characterized in that the two housing shells (8) accommodate the
axial roller bearings (6) in a clearance-free manner.
6. Threaded mechanism with rolling bodies as claimed in any one of
claims 3 to 5, characterized in that facing frontal ends of legs
(9) of the housing (8) are configured as an abutment for axial
bearing rings (11) of the axial roller bearings (6).
7. Threaded mechanism with rolling bodies as claimed in claim 6,
characterized in that the facing frontal ends of the legs (9)
include projecting, convexly shaped abutments (10) for the axial
bearing rings (11) of the axial roller bearings (6).
8. Threaded mechanism with rolling bodies as claimed in claim 1,
characterized in that the legs (9) are elastically deflectable.
9. Threaded mechanism with rolling bodies as claimed in any one of
claims 1 to 8, characterized in that a radial roller bearing (12)
is arranged for the radial mounting support of the spindle nut
(4).
10. Threaded mechanism with rolling bodies as claimed in claim 9,
characterized in that a bearing seat being designed on the housing
(8) is provided for the radial roller bearing (12), a radial
clearance (R) being arranged between the bearing seat and the
radial roller bearing (12).
11. Threaded mechanism with rolling bodies as claimed in claim 9 or
10, characterized in that a damping element (14) for damping radial
movements of the spindle nut (4) is arranged between the housing
(8) and the radial roller bearing (12).
12. Threaded mechanism with rolling bodies as claimed in any one of
claims 9 to 11, characterized in that the bearing seat for the
radial roller bearing (12) has a hollow-cylindrical design and
includes a circumferential groove (13) housing a rubber-elastic,
annularly closed damping element (14), which at least partly
projects from the groove (13) in a radially inward direction.
13. Threaded mechanism with rolling bodies as claimed in any one of
claims 9 to 12, characterized in that the rolling bodies (3) of the
threaded mechanism with rolling bodies have a spherical design.
14. Drive device of an automotive vehicle axle guide module with a
threaded mechanism with rolling bodies as claimed in claim 1,
characterized in that the drive device includes a rotary drive that
is connected to the spindle nut (4) in terms of driving by way of a
flexible torque clutch.
15. Drive device as claimed in claim 14, characterized in that the
spindle rod (1) of the threaded mechanism with rolling bodies is
arranged in an axial direction behind a movable component of the
automotive vehicle axle guide module that is connected or
connectable to a steering wheel operable by a driver and, by
displacement, effects turning of steerable vehicle wheels.
16. Drive device as claimed in claim 15, characterized in that the
movable component of the automotive vehicle axle guide module is a
toothed rack to which the spindle rod (1) is rigidly connected.
Description
TECHNICAL FIELD
[0001] The present invention generally relates to threaded
mechanisms and more particularly relates to threaded mechanisms
with interposed rolling bodies.
BACKGROUND OF THE INVENTION
[0002] Radial forces may be produced in threaded mechanisms with
rolling bodies in different applications. In many applications,
these radial forces, give rise to premature wear of the threaded
mechanism. For example, in steering gears for vehicles, radial
forces can act on the steering rod due to the travel-responsive
inclined position of the steering tie rods coupled to the wheels,
said radial forces producing friction forces in the bearings and
cause the entire steering rod to deflect.
BRIEF SUMMARY OF THE INVENTION
[0003] An object of the present invention is to develop a threaded
mechanism with rolling bodies and a drive mechanism of an
automotive vehicle axle guide module in such a manner that the
mounting support of a spindle nut is exposed to an evenly
distributed load.
[0004] According to the invention, this object is achieved in that
in a threaded mechanism with rolling bodies, which includes a
spindle rod, a spindle nut enclosing the said spindle rod at least
in part, and a number of interposed rolling bodies, there is
provision of an axial and radial mounting support for the spindle
nut that is so designed as to allow both tilting movements of the
spindle nut about its longitudinal axis and radial movements
transversely relative to its longitudinal axis.
[0005] Consequently, it is essential for the threaded mechanism
with rolling bodies of the invention that an axial and radial
mounting support is provided for a spindle nut that is operatively
connected to the spindle rod by the intermediary of rolling bodies,
with said mounting support permitting tilting movements of the
spindle nut about its longitudinal axis and radial movements of the
spindle nut transversely relative to its longitudinal axis.
Advantageously, the threaded mechanism with rolling bodies of the
invention allows achieving an evenly distributed load on the
mounting support. This means that defined flexibility is ensured
and a defined radial clearance admitted in addition.
[0006] In a preferred embodiment of the invention, at least one
axial roller bearing is provided for the axial mounting support of
the spindle nut having a radial flange, the frontal ends of which
are designed as an abutment for the axial roller bearing. This
renders it possible that the mounting support in the axial bearing
is evenly loaded.
[0007] According to a preferred embodiment of the invention, the
axial mounting support is provided on a housing that is designed on
facing frontal ends as an abutment for the axial roller
bearing.
[0008] According to a preferred embodiment of the invention, the
housing includes two housing shells subdivided transversely
relative to the axis of rotation of the threaded spindle, and each
one axial roller bearing is interposed between the radial flange
and each of the housing shells.
[0009] The two housing shells accommodate the axial bearings in a
clearance-free manner according to a favorable aspect of the
invention.
[0010] According to a favorable aspect of the invention, facing
frontal ends of legs of the housing are configured as an abutment
for axial bearing rings of the axial roller bearings.
[0011] It is arranged for according to a preferred embodiment of
the invention that the facing frontal ends of the legs include
projecting, convexly shaped abutments for the axial bearing rings
of the axial roller bearings. These abutments are used to ensure
defined flexibility by permitting a defined tilting of the axial
bearing rings and thus of the spindle nut.
[0012] According to a preferred embodiment of the invention, the
legs are elastically deflectable. Preferably, the legs and also the
radial flange are elastically deflectable.
[0013] A radial roller bearing is arranged for the radial mounting
support of the spindle nut according to a preferred embodiment of
the invention.
[0014] According to a preferred embodiment of the invention, a
bearing seat being designed on the housing is provided for the
radial roller bearing, and a radial clearance is arranged between
the bearing seat and the radial roller bearing.
[0015] According to a preferred embodiment of the invention, a
damping element for damping radial movements of the spindle nut is
arranged between the housing and the radial roller bearing.
[0016] According to a preferred embodiment of the invention, the
bearing seat for the radial roller bearing has a hollow-cylindrical
design and includes a circumferential groove housing a
rubber-elastic, annularly closed damping element, which at least
partly projects from the groove in a radially inward direction.
[0017] According to a preferred embodiment of the invention, the
rolling bodies of the threaded mechanism with rolling bodies have a
spherical design.
[0018] This object is likewise achieved by a drive device of an
automotive vehicle axle guide module with a threaded mechanism with
rolling bodies of the invention, being characterized in that the
drive device includes a rotary drive that is connected to the
spindle nut in terms of driving by way of a flexible torque
clutch.
[0019] According to a preferred embodiment of the invention, the
threaded spindle of the threaded mechanism with rolling bodies is
arranged in an axial direction behind a movable component of the
automotive vehicle axle guide module that is connected or
connectable to a steering wheel operable by a driver and, by
displacement, effects turning of steerable vehicle wheels.
[0020] According to a preferred embodiment of the invention, the
movable component of the automotive vehicle axle guide module is a
toothed rack to which the threaded spindle is rigidly
connected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is the threaded mechanism of the present invention
including rolling bodies along the longitudinal axis, with a
cross-section taken through the spindle nut.
[0022] FIG. 2 is a cross-sectional view of the threaded mechanism
with rolling bodies shown in FIG. 1 transversely to the
longitudinal axis in the area of the spindle nut.
[0023] FIG. 3 is a perspective view of the threaded mechanism with
rolling bodies shown in FIG. 1.
[0024] FIG. 4 is a cutout of the threaded mechanism with rolling
bodies shown in FIG. 1, with a cross-section taken through the
spindle nut along the longitudinal axis of the threaded mechanism
with rolling bodies.
[0025] FIG. 5 is an enlarged view of a cutout of the spindle nut
shown in FIG. 4.
[0026] FIG. 6 is a schematic view of the possible movements of the
threaded mechanism with rolling bodies.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] The threaded mechanism with rolling bodies illustrated in
FIG. 1, FIG. 2, and FIG. 3 is an independent functional subassembly
wherein a spindle rod (1) could be part of a toothed rack
subassembly of an automotive vehicle axle guide module. The
threaded mechanism with rolling bodies comprises a ball screw (2)
and spherical rolling bodies (3) between the spindle rod (1) and a
spindle nut (4). It is used herein as a rotation/translation gear
unit of the drive device of the axle guide module. The threaded
mechanism with rolling bodies is designed by a corresponding
mounting support (5) of the spindle nut (4) in such a manner that
both tilting movements of the spindle nut (4) about its
longitudinal axis and radial movements transversely relative to its
longitudinal axis are permitted.
[0028] The mounting support (5) of the spindle nut (4) is
illustrated in detail in FIG. 4 and FIG. 5. The axial mounting
support of the spindle nut (4) is carried out by means of two axial
roller bearings (6) interposed between a radial flange (7) and two
housing shells (8) subdivided transversely relative to the
longitudinal axis of the threaded spindle (1). This mounting
support is generally clearance-free. But a tilting movement of the
spindle nut (4) about its longitudinal axis is rendered possible by
legs (9) of the housing shells (8), which include convexly shaped
abutments (10) for axial bearing rings (11) of the axial roller
bearings (6), said abutments projecting from facing frontal ends of
said legs. Legs (9) and, as the case may be, the radial flange (7)
are elastically deflectable and permit tilting movement of the
spindle nut (4) by tilting of the axial roller bearings (6) or the
axial bearing rings (11) in the range of the elastic deformation.
This achieves an elastic mounting support in contrast to a coaxial
stiff connection to the spindle rod (1). The radial mounting
support of the spindle nut (4) is carried out by means of a radial
roller bearing (12), which is arranged on a bearing seat (13)
designed on the housing shells (8), with a radial clearance (R)
provided between the housing shells (8) and the radial roller
bearing (12). Arranged between the housing shells (8) and the
radial roller bearing (12) is a damping element (14) that is used,
on the one hand, to prevent co-rotation of the housing shells (8)
and thus to safeguard the function of the bearing and, on the other
hand, serves for dampening radial movements of the spindle nut. The
bearing seat (13) for the radial roller bearing (12) has a
hollow-cylindrical design and includes a circumferential groove
(15) in which the damping element (14) is incorporated. The damping
element (14) is preferably an O-ring made of a rubber-elastic
material and projects at least partly from said groove in a
radially inward direction.
[0029] As shown in FIG. 6, when the threaded mechanism of the
present invention is incorporated into an automatic vehicle axle
guide, the spindle rod (1) can deform, when exposed to the load of
radial forces (17), and a corresponding elastic line (18) is
produced. If the spindle rod (1) was hindered by a
bending-resistant mounting support of the spindle nut (4) to effect
a certain tilt (38) about the imaginary axis (X), very high radial
forces would be exerted on the bearings due to the length of the
bearing. These radial forces can cause a poor mechanical efficiency
or lead to the destruction of individual components. In addition,
an unsymmetrical load of the ball tracks (2) would occur in the
screw thread shown in FIG. 1 and reduce the load capacities and
useful life of the threaded mechanism.
[0030] Induced by the elastic line (18), the axial roller bearings
(6) and the axial bearing rings (11), due to the defined elastic
deformability of the legs (9), will oscillate to balance the
unsymmetrical stress, and the spindle nut (4) can align itself to
the elastic line (18). As this occurs, the spherically and convexly
configured abutment surfaces (10) of the legs (9) will transmit the
acting axial force onto the axial roller bearings (6) always at a
right angle and centrically through the axial bearing rings (11),
also by deforming the legs (9) and possibly the radial flange (7).
This renders the load on the rolling bodies (3) more uniform,
increases their load capacity, the efficiency and total useful life
of the axial roller bearings (6).
[0031] The radial escape of the spindle rod (1) and the spindle nut
(4) is intercepted by the integrated radial roller bearing (12)
when an integrated clearance (R) is exceeded. The spindle rod is
stabilized radially in its center when increased forces prevail.
This is because the radial roller bearing (12), retained by the
O-ring (14), runs without load in a defined range, dependent on
clearance (R). As a whole, favorable improvements of the total
efficiency and the response characteristic of the threaded spindle
mechanism are achieved by the radial and flexible drive and bearing
of the present invention. In order to ensure the zero backlash of
the threaded mechanism with rolling bodies, the entire threaded
mechanism is pre-assembled in a ring (16) with a defined preload of
the two housing shells (8), thus forming a subassembly that is easy
to integrate at a later time. The preload of the axial roller
bearing (6) is preferably achieved by calking ring (16) within
axial limits. Calking is limited by measuring the stall torque of
the spindle nut (4). It is also possible to realize the connection
by a screw coupling or other known types of connection. Ring (16)
is stationarily fitted to the automotive vehicle axle guide module.
The threaded mechanism with rolling bodies is then a subassembly of
a drive device with a rotary drive that is connected in terms of
driving to the spindle nut (4), preferably by way of a flexible
torque clutch. The threaded spindle (1) of the threaded mechanism
with rolling bodies is movable by the spindle nut (4), with the
result that the toothed rack arranged behind it in an axial
direction is entrained and brings about turning of steerable
vehicle wheels.
* * * * *