U.S. patent number RE46,242 [Application Number 13/940,450] was granted by the patent office on 2016-12-20 for device for actuating a gearwheel, which is designed as a loose wheel, of a transmission device.
This patent grant is currently assigned to ZF Friedrichshafen AG. The grantee listed for this patent is ZF FRIEDRICHSHAFEN AG. Invention is credited to Ralf Dreibholz, Mark Mohr, Matthias Reisch.
United States Patent |
RE46,242 |
Mohr , et al. |
December 20, 2016 |
Device for actuating a gearwheel, which is designed as a loose
wheel, of a transmission device
Abstract
A device (4) for actuating a component mounted to rotate on a
shaft (3), preferably a gearwheel (3A to 3D) made as a loose wheel
of a transmission device (1). The component can be shifted by an
engaging device (4A, 4B) that includes at least one electric
actuator (5, 17) to an engaged condition in which the component is
connected in a rotationally fixed manner to the shaft (3), and such
that the component can be acted upon with the actuation force
needed for its engagement or disengagement from inside the shaft
(3) outwardly. The electric actuator (5, 17) is at least partially
arranged inside the shaft (3).
Inventors: |
Mohr; Mark (Tettnang,
DE), Reisch; Matthias (Ravensburg, DE),
Dreibholz; Ralf (Meckenbeuren, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
ZF FRIEDRICHSHAFEN AG |
Friedrichshafen |
N/A |
DE |
|
|
Assignee: |
ZF Friedrichshafen AG
(Friedrichshafen, DE)
|
Family
ID: |
38828723 |
Appl.
No.: |
13/940,450 |
Filed: |
July 12, 2013 |
PCT
Filed: |
October 02, 2007 |
PCT No.: |
PCT/EP2007/060456 |
371(c)(1),(2),(4) Date: |
March 26, 2009 |
PCT
Pub. No.: |
WO2008/046736 |
PCT
Pub. Date: |
April 24, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
12443037 |
Oct 2, 2007 |
8245589 |
Aug 21, 2012 |
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Foreign Application Priority Data
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Oct 19, 2006 [DE] |
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10 2006 049 274 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16H
61/32 (20130101); F16H 3/002 (20130101); F16H
63/304 (20130101); F16H 3/083 (20130101); F16H
3/00 (20130101); Y10T 74/2003 (20150115); Y10T
74/1946 (20150115); Y10T 74/19465 (20150115); F16H
2063/3063 (20130101) |
Current International
Class: |
F16H
3/083 (20060101); F16H 3/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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4325964 |
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Jan 1995 |
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DE |
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19851738 |
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May 2000 |
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DE |
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19921064 |
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Nov 2000 |
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DE |
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10206584 |
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Sep 2003 |
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DE |
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10302502 |
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Sep 2004 |
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DE |
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0391604 |
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Oct 1990 |
|
EP |
|
1357317 |
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Oct 2003 |
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EP |
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2005/036007 |
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Apr 2005 |
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WO |
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2007/099034 |
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Sep 2007 |
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WO |
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Primary Examiner: Dawson; Glenn K
Attorney, Agent or Firm: Davis & Bujold PLLC Bujold;
Michael J.
Claims
The invention claimed is:
1. A device (4) for actuating a component mounted to rotate on a
shaft (3), the device comprising: an engaging device (4A, 4B) that
is axially movable along the shaft (3) within a slot (10B) in the
shaft (3) by at least one electric actuator (5, 17) between at
least first and second axial positions; the component has a profile
and is spaced from the shaft (3); the engaging device (4A, 4B)
comprises a profile and extends radially through the slot (10B) in
the shaft (3) and, in the first axial position, the profile of the
engaging device (4A, 4B) is located within the component, and the
profile of the engaging device (4A, 4B) engages the profile of the
component such that the component is rotationally fixed to the
shaft (3); in the second axial position of the .[.electric actuator
(5, 17).]. .Iadd.engaging device (4A, 4B).Iaddend., the profile of
the engaging device (4A, 4B) is disengaged from the profile of the
component; the at least one electric actuator (5, 17) is arranged
at least partially inside and coaxially with the shaft (3);
.Iadd.and a first end of the shaft (3) being supported by a first
bearing and a second end of the shaft (3) being supported by a
second bearing which facilitate rotation of the shaft (3);
.Iaddend. wherein the electric actuator (5, 17) is
.[.nonrotatably.]. connected to a housing .[.component.]. (7) and
the shaft (3) is rotationally supported by the housing
.[.component.]. (7) such that the shaft (3) rotates with respect to
.[.the electric actuator (5, 17) and.]. the housing .[.component.].
(7).
2. The device according to claim 1, wherein the engaging device
(4A, 4B) comprises a drive converter device (8, 14) and is located
between the actuator (5, 17) and the component, the drive converter
device (8, 14) converts rotary drive from the actuator (5, 17) to
translational drive movement.
3. The device according to claim 2, wherein the drive converter
device (8, 14) is a spindle-nut arrangement with or without
self-locking.
4. The device according to claim 2, wherein a transmission is
arranged in a direction of drive power flow between the actuator
and the drive converter device.
5. The device according to claim 1, wherein the electric actuator
(5, 17) is an electric motor by which an existing shift status of
the component can be maintained.
6. The device according to claim 1, wherein the actuator (5, 17)
applies a detent torque to maintain a shift status of the
component.
7. The device according to claim 1, wherein the actuator (5, 17) is
at least controlled and regulated as a function of at least one of
an existing shift status of the engaging device (4A, 4B),
associated with the component, and an actual drive power.
8. The device according to claim 1, wherein a plurality of
actuators (5, 17) are combined in a module.
9. The device according to claim 1, wherein at least one of an
electronic power unit and a control unit (6), associated with the
electric actuator (5,17), is arranged at least partially inside the
shaft (3).
10. The device according to claim 1, wherein at least one of an
electronic power unit and a control unit (6) is combined with the
electric actuator (5, 17) to form a common module.
11. The device according to claim 1, wherein an electric energy
storage (7A) associated with the actuator (5) is arranged at least
partially inside the shaft (3), the electric energy storage (7A)
stores electric energy and supplies the actuator (5) with the
electric energy.
12. The device according to claim 1, wherein a portion of the
actuator is arranged inside the shaft and comprises an oil duct for
the passage of hydraulic fluid.
13. The device according to claim 1, wherein the component mounted
to rotate on a shaft (3) is a loose gearwheel (3A to 3D) of the
transmission device (1).
14. A device (4) for actuating a component mounted to rotate on a
shaft (3), the device comprising: an engaging device (4A, 4B) that
is axially movable along the shaft (3) within a slot (10B) in the
shaft (3).Iadd., .Iaddend.by at least one electric actuator (5,
17).Iadd., .Iaddend.between at least first and second axial
positions; the component has a profile and is spaced from the shaft
(3); the engaging device (4A, 4B) comprises a profile and extends
radially through the slot (10B) in the shaft (3) and, in the first
axial position, the profile of the engaging device (4A, 4B) is
located within the component, and the profile of the engaging
device (4A, 4B) engages the profile of the component such that the
component is rotationally fixed to the shaft (3); in the second
axial position of the .[.electric actuator (5, 17).].
.Iadd.engaging device (4A, 4B).Iaddend., the profile of the
engaging device (4A, 4B) is disengaged from the profile of the
component; .Iadd.and .Iaddend. the at least one electric actuator
(5, 17) is arranged at least partially inside and coaxially with
the shaft (3); wherein an electrically controlled brake
communicates with the actuator to maintain a shift status of the
component by preventing a change of the shift status of the
component when the actuator is not energized.
15. A device (4) for engaging a gear wheel (3A, 3B, 3C, 3D) to a
hollow transmission shaft (3) such that the gear wheel and the
hollow shaft are nonrotatable with respect to each other, and the
gear wheel (3A, 3B, 3C, 3D), in a disengaged state, being freely
rotationally supported by the hollow shaft (3), the device
comprising: an electric actuator (5, 17) is coaxially aligned with
the hollow shaft (3) and located within an interior of the hollow
shaft (3), the electric actuator (5, 17) rotationally actuates a
spindle (8A) which engages a nut (8B), the nut (8B) is axially
slidable and rotationally fixed with respect to the shaft .[.such
that.]. .Iadd.and .Iaddend.the nut (8B) is axially biased within
the interior of the hollow shaft (3) by rotation of the spindle
(8A); a first end of pins (9A, 9B) are .[.immovably fixed.].
.Iadd.connected .Iaddend.to the nut (8B) and radially extend
through slots (10A, 10B) in the hollow shaft (3); a second opposite
end of the pins is .[.statically.]. connected to a sleeve (11),
.Iadd.the sleeve .Iaddend.(11) is rotationally fixed to the hollow
shaft (3) and axially slidable thereon, the first end of the pins
(9A, 9B) are .[.fixed.]. .Iadd.connected .Iaddend.to the nut (8B)
within the interior of the hollow shaft (3), such that as the nut
(8B) is axially driven within the hollow shaft by rotation of the
spindle (8A); and the sleeve (11) is axially slidable along the
hollow shaft (3) .Iadd.into a first position such that the sleeve
(11), in the first position, is at least partially arranged
.Iaddend.radially between the gear wheel (3A, 3B, 3C, 3D) and the
hollow shaft (3) .[.such that in a first position,.]..Iadd., and
.Iaddend.a .[.radially exterior.]. .Iadd.radial .Iaddend.profile of
the sleeve (11) engages a .[.radially interior.]. .Iadd.radial
.Iaddend.profile of the gear wheel (3A, 3B, 3C, 3D).
.Iadd.16. A transmission device (1) for actuating a loose wheel
component mounted on a shaft (3) for rotation with the shaft with
respect to a housing, the transmission device (1) comprising: a
pre-assembled module being insertable into the shaft during
assembly, the pre-assembled module comprising an engaging device
(4A, 4B), at least one electric actuator (5, 17), and at least one
control and power electronic unit (6) associated with the at least
one electric actuator (5, 17); a pin of the engaging device (4A,
4B) being axially movable, by the at least one electric actuator
(5, 17), along and within a slot in the shaft between at least
first and second axial positions for shifting the loose wheel
component via actuation of the engaging device (4A, 4B); in the
first axial position, the pin of the engaging device (4A, 4B),
being located relative to the loose wheel component so that a
profile of the engaging device (4A, 4B) engages with a profile of
the loose wheel component and rotationally fixes the loose wheel
component to the shaft (3); in the second axial position, the
profile of the engaging device being disengaged from the profile of
the loose wheel component so that the loose wheel component is
rotatable relative to the shaft (3); the shaft (3) being
rotationally supported by spaced apart first and second bearings
which facilitates rotation of the shaft (3) with respect to the
housing (7); and at least a portion of an energy and control signal
transmission device (15) being supported by the
housing..Iaddend.
.Iadd.17. The device according to claim 16, wherein a portion of
the shaft (3) is located between the energy and control signal
transmission device (15) and the second bearing..Iaddend.
.Iadd.18. The device according to claim 17, wherein the energy and
control signal transmission device is an inductive rotary
transmitter (15) by which both drive energy, required for driving
the engaging device (4), and two-directional control signals (28)
are exchanged without contact via an inductive transfer.
.Iaddend.
.Iadd.19. The device according to claim 16, wherein the engaging
device (4A, 4B) has a drive converter device (8, 14) which couples
the at least one electric actuator (5, 17) to the loose wheel
component by which rotary drive of the at least one electric
actuator (5, 17) is converted into translational drive
movement..Iaddend.
.Iadd.20. The device according to claim 18, wherein the drive
converter device (8, 14) is a spindle-nut arrangement with or
without self-locking..Iaddend.
.Iadd.21. The device according to claim 16, wherein the at least
one electric actuator (5, 17) applies a retaining torque for
maintaining a shift status of the loose wheel
component..Iaddend.
.Iadd.22. The device according to claim 16, wherein the at least
one electric actuator (5, 17) is at least controlled and regulated
as a function of at least one of an existing shift status of the
engaging device (4A, 4B), associated with the loose wheel
component, and an actual drive power..Iaddend.
.Iadd.23. The device according to claim 16, wherein a plurality of
actuators (5, 17) are contained within the preassembled
module..Iaddend.
.Iadd.24. The device according to claim 16, wherein the
pre-assembled module, which comprises the engaging device (4A, 4B),
the at least one electric actuator (5, 17) and the at least one
control and power electronic unit (6), is connected in a rotational
manner relative to the housing of the transmission device (1) such
that the pre-assembled module rotates with respect to the
housing..Iaddend.
.Iadd.25. The device according to claim 16, wherein a drive
converter device (8, 14) and the at least one control and power
electronic unit (6) are combined with the at least one electric
actuator (5, 17) to form the pre-assembled module..Iaddend.
.Iadd.26. The device according to claim 16, wherein the
preassembled module further comprises an electric energy
accumulator (7A), associated with the at least one electric
actuator (5), so as to be arranged at least partially inside the
shaft (3)..Iaddend.
.Iadd.27. The device according to claim 16, wherein at least one
energy and control signal is transferred between at least one
exterior component and the energy and control signal transmission
device (15); and the at least one exterior component is connected
to the housing..Iaddend.
.Iadd.28. The device according to claim 16, wherein a portion of
the at least one electric actuator, that is arranged inside the
shaft, is provided with an oil duct for passage of hydraulic
fluid..Iaddend.
Description
This application is a National Stage completion of
PCT/EP2007/060456 filed Oct. 2, 2007, which claims priority from
German patent application serial no. 10 2006 049 274.9 filed Oct.
19, 2006.
FIELD OF INVENTION
The invention concerns a device for actuating a gearwheel designed
as a loose wheel of a transmission device.
BACKGROUND OF THE INVENTION
In step-down transmissions known from practice, to engage or
disengage gearwheels designed as loose wheels, as a rule shift
elements such as synchronizers, claw or frictional elements are
actuated by means of shift forks or shift rockers which, in
relation to the shaft carrying the loose wheel or a plurality of
loose wheels, act upon the shift elements from the outside. In such
a case a minimum distance between two loose wheels arranged next to
one another, which can be actuated by a common shift element, is
determined among other things by the width of a shift sleeve and in
addition by the shift path that the shift sleeve has to cover in
order to engage the two loose wheels.
Disadvantageously, step-down transmissions in which shift elements
are actuated from outside take up a lot of space in the radial
direction, such space being of only limited availability especially
in automobiles.
To reduce the radial space taken up by a transmission, a change has
been made toward actuating shift elements of transmission devices
such as double-clutch transmissions, automated variable-speed
transmissions or planetary transmissions, from the inside of a
shaft carrying loose wheels extend outward, so that from DE 102 06
584 A1, DE 43 25 964 A1 and DE 103 02 502 A1 various systems are
known for actuating shift elements extending outward from a shaft
by means of a hydraulic, pneumatic, mechanical and/or
electromechanical control system.
In mechanical or electromechanical actuating systems known from the
prior art for a shift element provided for engaging or disengaging
a gearwheel designed as a loose wheel, it is provided for example
that the shift element is actuated by a rod passing through the
shaft. On the circumferential side of the shaft or the gearset
comprising the loose wheel a suitable shift system for producing an
H-shift pattern or for electrical actuation is required, but this
increases the manufacturing costs and the weight of a transmission
device to an undesired extent. Furthermore, the shift system
arranged in the circumferential area of a shaft takes up a lot of
structural space in the radial direction and also causes friction
losses.
SUMMARY OF THE INVENTION
Accordingly, the purpose of the present invention is to provide a
device for actuating a component mounted to rotate on a shaft,
preferably a gearwheel designed to be a loose wheel of a
transmission device, which can be produced simply and
inexpensively, takes up little structural space and has low
component weight, and whose use enables a transmission to be
operated with good efficiency.
In the device according to the invention for actuating a component
mounted to rotate on a shaft, preferably a gearwheel of a
transmission device, made as a loose wheel, this component being
able to be manipulated, by at least one engaging device that
comprises an electric actuator, to an engaged condition in which
the first gearwheel is connected in rotationally fixed manner to
the shaft, such that the first gearwheel can be acted upon with the
actuation force required for its engagement or disengagement from
inside the shaft outward, the at least one electric actuator is
arranged at least partially inside the first shaft.
In this way, structural space available in conventional
transmission devices inside shafts that carry loose gearwheels,
which shafts are often made centrally hollow in order to save
weight, is in a simple manner utilized by arranging in this area at
least one electric actuator provided for the actuation of a
gearwheel made as a loose wheel, so that the structural space
required for the transmission device is reduced in the radial
and/or the axial direction in a simple manner.
The use of the electric actuator and the arrangement of the
actuator on the inside of the shaft carrying the loose wheel to be
actuated makes it possible in a simple manner to do without any
external shifting means known from the prior art, and thus to save
structural space in the circumferential area of the shaft.
Furthermore, thanks to the structurally more simple design of the
engaging device compared with conventional transmission devices,
the overall weight of the transmission device is also reduced. In
addition, compared with shift systems known from the prior art
frictional losses during the actuation of a loose wheel are
reduced, due to the smaller diameter range within which an
actuation or a transmission of the loose wheel actuating force
required for engagement or disengagement of the wheel takes
place.
In an advantageous further development of the device according to
the invention, the electric actuator is connected in a rotationally
fixed manner to a housing of the transmission device, whereby
energy exchange and data transfer between the electric actuator and
components of a transmission device or of another system comprising
the device according to the invention, which are fixed on the
housing and which co-operate with the actuator, such as a wedge
brake system, can be effected in a simple manner.
Alternatively, in a further advantageous embodiment of the device
according to the invention it is provided that the electric
actuator is connected in a rotationally fixed manner to the shaft
carrying the rotating component, and therefore rotates at the speed
of the shaft during operation. This offers the advantage that the
electric actuator can be inserted into the shaft before the shaft
is fitted into a housing, forming a pre-assembled module with the
shaft which, during final assembly of a transmission device or
other system, can be fitted into a housing in a single assembly
step. In addition, with this design the correct operation of the
device can be tested using appropriate testing means outside the
housing of the transmission device or other system.
Another advantageous embodiment of the device for actuating a
component mounted to rotate on a shaft, preferably a gearwheel made
as a loose wheel, is characterized by a drive converter device of
the engagement device arranged between the actuator and the
component, by means of which a rotary drive of the actuator can be
converted into a translational drive movement inside the shaft in a
manner advantageous in terms of structural space.
In a further development of the above embodiment of the device
according to the invention, the drive converter device is made as a
spindle-nut arrangement with or without self-locking, by which the
rotary drive of the actuator can be converted by simply designed
means and in an inexpensive manner into a translational drive
movement for producing the actuation force needed to engage or
disengage the component.
To keep the drive power of the electric motor and hence its space
requirement as small as possible, an advantageous embodiment of the
device according to the invention is made with a transmission,
preferably a planetary transmission 22 (FIG. 1), between the
actuator and the drive converter device, by means of which the
drive power of the electric actuator can be transformed to a value
necessary for actuating the component.
In a further advantageous embodiment of the device according to the
invention, the electric actuator is made as an electric motor by
means of which, preferably, an existing shift status of the
component can be maintained, so that there is no need for
additional structural elements to maintain the shift status of the
component.
Alternatively, in a further advantageous design of the device
according to the invention it is provided that an electrically
controlled brake is associated with the actuator to maintain the
shift status of the component, this brake preventing any change of
the component's shift status when it is not energized.
Depending on the design of the component to be actuated by the
actuator, the actuator can be controlled and/or regulated as a
function of an existing shift status of the component and/or of a
currently necessary drive power. For example, if driving the
actuator actuates a shift claw that engages a loose wheel of a
transmission device, then the actuator's operation is controlled
and/or regulated depending on the current position of the shift
claw. If a frictional disk-type shift element of a transmission is
controlled by the actuator, then the drive power of the actuator is
adjusted under control and/or regulation since the torque that can
be transmitted by a disk-type shift element depends on the
actuating force applied to its frictional elements.
BRIEF DESCRIPTION OF THE DRAWINGS
Other advantages and advantageous further developments of the
invention emerge from the claims and the example embodiments
described in principle with reference to the drawing. For the sake
of clarity, in the description of the various example embodiments
components having the same structure and function are indexed in
the same way. The drawings show:
FIG. 1: A schematic partial longitudinal section view of a first
example embodiment of a device according to the invention, arranged
in a step-down transmission; and
FIG. 2: Representation corresponding to that of FIG. 1, of a second
example embodiment of the device according to the invention, used
for engaging and disengaging loose wheels of a step-down
transmission.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows part of a transmission device 1 made as a step-down
transmission, seen in a longitudinal section view, which comprises
a main transmission shaft 2 and arranged parallel to it, a
countershaft 3. On the main transmission shaft 2 are arranged a
plurality of gearwheels 2A to 2D made as fixed wheels, which mesh
with a plurality of gearwheels 3A to 3D mounted to rotate on the
countershaft and made as loose wheels. The loose wheels 3A and 3B
can be engaged by means of a first engaging device 4A of a device 4
for actuating the gearwheels 3A to 3D, whereas the loose wheels 3C
and 3D can be engaged and thus connected in a rotationally fixed
manner to the countershaft 3 by means of a second engaging device
4B of the device 4.
The engaging devices 4A and 4B of the device 4 have basically the
same structure, so in the description of FIG. 1 below, essentially
only the engaging device 4A will be described.
The engaging device 4A is made with an electric actuator 5 in this
case consisting of an electric motor and, associated with the
electric actuator 5, a control and power electronic unit 6, both of
which are connected in a rotationally fixed manner to a housing
component 7 of the housing of the transmission device 1. A motor
output shaft (not shown) of the electric actuator 5 is connected in
a rotationally fixed manner to a spindle 8A of a spindle-nut
arrangement 8, so that when the actuator drives the spindle 8A it
rotates and a nut 8B engaged with the spindle, which is prevented
from rotating by anti-rotation means (also not shown), is moved in
the axial direction of the countershaft 3 away from the electric
actuator 5 or toward it.
In this case the nut 8B is actively connected to two pins 9A and 9B
that pass through the countershaft 3 in such manner that the pins
9A and 9B are pushed by the nut 8B in the axial direction of the
countershaft 3 along slots 10A, 10B of the countershaft 3. During
operation of the countershaft 3 the pins 9A and 9B rotate at the
speed of the countershaft 3 about the rotation axis of the
countershaft 3, whereas the nut 8B cannot rotate. This means that
in the area between the pins 9A and 9B and the nut 8B for actuating
the loose wheels 3A and 3B, speed decoupling means are
provided.
To be able to couple the loose wheel 3A or the loose wheel 3B in a
rotationally fixed manner to the countershaft 3 and so change it
from a disengaged to an engaged condition, the pins 9A and 9B are
connected at their end remote from the nut 8B to a sleeve element
11 that surrounds the countershaft 3 and which is connected in a
rotationally fixed manner to the countershaft 3 by a form-locking
connection but which can move along the countershaft 3 in the axial
direction of the countershaft 3. Furthermore, in the area of its
circumferential surface facing away from the countershaft 3 the
sleeve element 11 is has a toothed profile 11A which, depending on
its axial position, engages with a toothed profile 12 connected
fixed to the loose wheel 3A, or with a toothed profile 13 connected
fixed to the loose wheel 3B, or is in a neutral, intermediate
position between the two toothed profiles 12 and 13 and engages
with neither of them, so that neither the loose wheel 3A nor the
loose wheel 3B is connected in a rotationally fixed manner to the
countershaft 3. The spindle-nut arrangement 8 and the spindle-nut
arrangement 14 in each case constitute a drive conversion device by
means of which rotary drive of an electric actuator can be
converted to translational drive movement for engaging or
disengaging the loose wheels 3A to 3D.
To avoid spontaneous engagement or disengagement of one of the
loose wheels 3A to 3D, in this case the spindle-nut arrangements 8
and 14 are of self-locking design so that without being driven by
the actuator the nut 8B of the spindle-nut arrangement 8 or the nut
14B of the spindle-nut arrangement 14 will hold their position.
Alternatively to the above, in other embodiments (not shown in the
drawing) of the device for actuating a component mounted to rotate
on a shaft or a gearwheel of a transmission device, made as a loose
wheel, it is provided that a shift status of the component can be
maintained by appropriate control of the electric actuator of the
engaging device by means of a retaining torque produced by the
actuator.
In addition or alternatively, it can also be provided that to
maintain the shift status of the component, for example a loose
wheel, an electrically controlled brake is associated with the
actuator, which prevents a change of the component's shift status
when it is not energized. When the electric actuator is made as an
electric motor the brake 24 is connected to the motor output shaft,
so that rotary movement of a spindle of a spindle-nut arrangement
is prevented when the electric motor is not energized.
Inside the countershaft 3, besides the electric actuator 5 and its
associated control and power electronic unit 6 an energy
accumulator .[.7.]. .Iadd.7A .Iaddend.for the storage of electrical
energy is also provided, which in the present case is in the form
of a capacitor by means of which a voltage supplied to the electric
actuator is smoothed. In addition or alternatively, the energy
accumulator .[.7.]. .Iadd.7A .Iaddend.preferably in the form of a
capacitor can also be used for the interim storage of electrical
energy needed for operating the electric actuator 5.
Moreover, the structural unit constituting a module and containing
the energy accumulator .[.7.]. .Iadd.7A.Iaddend., the control and
power electronic unit 6 and the electric actuator 5, is also
provided with oil ducts .[.20.]. through which, inside the
countershaft 3, hydraulic fluid for lubrication, cooling or
actuating various components of the transmission device 1 is passed
to the components concerned.
In a further development of the step-down transmission 1
illustrated in FIG. 1 the device 4 for actuating the loose wheels
3A to 3D which comprises the engaging devices 4A and 4B, is formed
in the area between the electric actuator 5 and the spindle-nut
arrangement 8 and an electric actuator 17 and the spindle-nut
arrangement 14, in a manner not illustrated, in each case with a
transmission device in order to be able to transform the drive
power of the electric actuator 5 by the necessary amount and to be
able to drive the spindle 8A and a spindle 14A, respectively, with
the torque required for the axial displacement of the spindle nuts
8B and 14B.
FIG. 2 shows a second example embodiment of a transmission device
1, which is different essentially only in the design of the device
4 for actuating the gearwheels 3A to 3D, so that in the description
below essentially only the differences will be described. In the
embodiment of the transmission device 1 shown in FIG. 2 the
electric actuators 5 of the device 4 for actuating the loose wheels
3A to 3D are connected in a fixed manner to the countershaft 3 and
therefore, during the operation of the transmission device 1, they
rotate at the speed of the countershaft 3. Accordingly, no longer
is any mechanical speed decoupling needed in the area between the
spindle nuts 8B and 14B and the bolts 9A, 9B and 16A, 16B.
Energy and/or control signal transmission between components
.[.26.]. provided outside the countershaft 3 and fixed on the
housing and the actuators 5 and 17 connected in a rotationally
fixed manner to the countershaft 3, is in this case carried out by
a rotary transmitter 15 that works on the induction principle. By
means of the inductive rotary transmitter 15 both the drive energy
needed for driving the electric actuators 5 and 17, and also the
necessary two-directional control signals .[.28.]., i.e. nominal
and actual values, are exchanged with no contact. Alternatively to
the inductive transmission of the energy and the control signals,
these can also be transferred by an appropriate sliding contact
system .Iadd.30.Iaddend..
Both of the engaging devices 4A and 4B are parts of a module which
can be inserted in its entirety into the inside of the countershaft
3 during assembly. For this, during assembly a rotation of the
module, preferably by .[.900.]. .Iadd.90 degrees .Iaddend.to its
axial end position is provided for, in order to form a connection
between the spindle nuts 8B and 14B and the pins 9A, 9B and 16A,
16B respectively. Then the module is connected in a rotationally
fixed manner to the countershaft 3 by suitable means such as a clip
connection, a screw connection, a pin connection, a bonding
connection or by wedging.
In a further advantageous design of the device according to the
invention the device is made with only one electric actuator for
applying the actuation force for the engagement or disengagement of
a component or gearwheel, this being a so-termed dedicated
selection actuator. By means of the selection actuator a choice can
be made between the various components or gearwheels to be
actuated, so that by means of the selection actuator a selected
gearwheel or component, or the shift element associated with it, is
acted upon by the actuation energy produced by the electric
actuator.
The selection actuator is in this case preferably made as a shift
magnet, which produces the connection between the electric actuator
of the device and the component or gearwheel to be actuated by the
device that is necessary for the component or gearwheel, or the
shift element associated with it, to be actuated.
In general the device described above is also suitable for other
self-reinforcing systems such as wedge brakes or wedge clutches, so
that the system provided for actuating the elements can simply be
made as a module and fitted in an appropriate position.
INDEXES
1 Transmission device 2 Main transmission shaft 2A to 2D Gearwheels
3 Countershaft 3A to 3D Gearwheels 4 Device 4A, 4B Engaging devices
5 Electric actuator 6 Control and power electronic unit 7 Housing
component 7A Energy accumulator 8 Spindle-nut arrangement 8A
Spindle 8B Nut 9A, B Pins 10A, B Slot 11 Sleeve element 11A Toothed
profile 12 Toothed profile 13 Toothed profile 14 Spindle-nut
arrangement 14A Spindle 14B Nut 15 Rotary transmitter 16A, B Pins
17 Actuator
* * * * *