U.S. patent application number 09/859434 was filed with the patent office on 2002-11-21 for auxiliary-bicycle torsion sensing and large gear plate minimization apparatus.
This patent application is currently assigned to Industrial Technology Research Institute. Invention is credited to Chiang, Chung-Ping, Liang, Chih-Ming, Liu, Ching-Wen, Wu, Ching-Huei, Yen, Cheng-Chung.
Application Number | 20020173397 09/859434 |
Document ID | / |
Family ID | 26614817 |
Filed Date | 2002-11-21 |
United States Patent
Application |
20020173397 |
Kind Code |
A1 |
Wu, Ching-Huei ; et
al. |
November 21, 2002 |
AUXILIARY-BICYCLE TORSION SENSING AND LARGE GEAR PLATE MINIMIZATION
APPARATUS
Abstract
An auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus, arranged in transmission apparatus of an
auxiliary-bicycle, includes a sun gear, a unidirectional device, a
planet gear set and a sensing device. The sun gear of planet gear
set is connected to the crank axle of auxiliary-bicycle and driven
directly with it. The stepping power of crank axle is output to the
large gear plate of auxiliary-bicycle through the transmission of
sun gear, planet gear and unidirectional device. Also, one side of
swing arm, used for pivotally arranging sun gear and planet gear,
is arranged with the sensing device. When crank axle is rotated by
the stepping force of rider, the swing arm will generate a rotation
torsion, and sensing device senses the torsion value to control the
power output of driving motor. The present invention has the
characteristics of simple structure, low manufacture cost, more
accurate sensitivity, and further instant changeable rotation ratio
between crank axle and large gear plate to meet the object of
broader application, such as the outlook beautification due to the
minimization of large gear plate.
Inventors: |
Wu, Ching-Huei; (Hsinchu,
TW) ; Liu, Ching-Wen; (ChangHua City, TW) ;
Chiang, Chung-Ping; (Taipei, TW) ; Yen,
Cheng-Chung; (Hsinchu, TW) ; Liang, Chih-Ming;
(KaoShiung, TW) |
Correspondence
Address: |
DOUGHERTY & TROXELL
SUITE 1404
5205 LEESBURG PIKE
FALLS CHURCH
VA
22041
US
|
Assignee: |
Industrial Technology Research
Institute
|
Family ID: |
26614817 |
Appl. No.: |
09/859434 |
Filed: |
May 18, 2001 |
Current U.S.
Class: |
475/2 |
Current CPC
Class: |
B62M 6/45 20130101; Y10T
74/19056 20150115; B62M 11/145 20130101; B62M 6/55 20130101 |
Class at
Publication: |
475/2 |
International
Class: |
B62M 023/02 |
Claims
What is claimed is:
1. An auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus, said apparatus being engaged with a
transmission apparatus of auxiliary-bicycle, said transmission
apparatus comprising at least a crank axle, a gear plate and a
speed-variation gear set; by rotating the crank axle, power output
of a driving apparatus of said auxiliary-bicycle can be controlled;
the power output driving the gear plate to rotate through the
transmission of transmission apparatus; said auxiliary-bicycle
torsion sensing and large gear plate minimization apparatus
comprising: a sun gear, which is fixed to the crank axle and driven
together with it to rotate; a planet gear set, which at least
includes a swing arm and a first planet gear; the swing arm
pivotally engaged with the crank axle and is capable of rotating
about the crank axle in a limited degree; the first planet gear is
pivotally engaged with the swing arm and driven together with the
sun gear to rotate; the first planet gear is driven to rotate by
the rotation of crank axle and further make the swing arm
generating a rotation torsion in the same rotation direction which
is same as that of sun gear; and a sensing apparatus, which
contacts with one side of the swing arm and may sense the rotation
torsion of the swing arm, and generates a sensing signal to control
the power output of driving apparatus.
2. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 1, further
comprising: a unidirectional device, which is connected to the gear
plate and may proceed a single direction transmission; and a second
planet gear, which is arranged at the planet gear set and driven to
rotate together with the second planet gear; the second planet gear
is driven together with the unidirectional device; the direction of
unidirectional transmission makes the second planet gear may drive
the gear plate to rotate; however the gear plate can not drive the
second planet to rotate.
3. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 2, wherein the
speed-variation gear set connects and drives the gear plate through
the transmission of the unidirectional device; the speed-variation
gear set may drive the gear plate to rotate through the
transmission of unidirectional device; however the gear plate can
not drive the speed-variation gear set to rotate.
4. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 2, wherein the
unidirectional device is a unidirectional ratchet device.
5. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 2, wherein the
speed-variation gear set is a speed-reduction gear set.
6. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 2, wherein the
speed-variation gear set is comprised of several matching together
multilevel gears.
7. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 2, wherein it further
includes a medium gear and a ring gear; the medium gear is matched
with the second planet gear; the ring gear is then also matched
with the medium gear and the unidirectional device.
8. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 1, wherein the
driving apparatus is an electric driving motor.
9. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 1, wherein the
sensing apparatus includes a pushing pillar and a stress sensor;
one end of the pushing pillar pushes against the swing arm; another
end is then connected with the stress sensor; the pushing pillar
may transfer the rotation torsion of swing arm to the stress
sensor.
10. The auxiliary-bicycle torsion sensing and large gear plate
minimization apparatus according to the claim 9, wherein the
sensing apparatus further includes a replacement element and a
pushing block; the pushing block pushes against the swing arm; the
replacement element connects to the pushing pillar and provides an
elastic force to make the pushing pillar maintain a predetermined
position under the state of no external force.
Description
FIELD OF THE INVENTION
[0001] The present invention is related to an auxiliary-bicycle
torsion sensing and large gear plate minimization apparatus,
especially to an apparatus arranged at the transmission apparatus
of auto-auxiliary-bicycle for sensing the torsion and acceleration
of stepping force as rider is riding the auto-auxiliary-bicycle.
Hence the large gear is minimized and the variation of outlook
beautification is met.
BACKGROUND OF THE INVENTION
[0002] In current market, the wheels of popular auto-bicycle (also
called auto-auxiliary-bicycle) are driven to rotate mainly by
arranging auxiliary devices at bicycle (auxiliary-bicycle), such as
battery, driving motor, and transmission apparatus, etc. When rider
steps on the treadles of bicycle, besides the stepping force drives
the wheels, the driven motor also generates a power that is
transmitted by transmission apparatus and drives bicycle's wheels
to rotate. Hence the strength of the rider to drive the bicycle may
be reduced and the object of auxiliary-bicycle is met.
[0003] Because the rider needs different powers output from driven
motor to drive the wheels according to the uphill and downhill
situations and to different driving speeds, each manufacturer also
develops stepping force sensor for detecting the stepping strength
of bicycle rider. And according to the stepping force detected by
the sensor, the power transmitted by the driven motor is
controlled. In general, the current prior stepping force sensing
manners includes following three methods: transferring torsion
value into axial displacement, absolute angular displacement and
relative angular displacement. Wherein the method of relative
angular displacement, during low driving speed, may not obtain a
continuous signal and therefore is scarcely adapted. As for axial
displacement and absolute angular displacement, their sensing
methods possess no such problem.
[0004] Also the large gear plate of traditional bicycle is too
large, during covering transmission chain, covering volume is too
big and outlook is disgraceful. If the size of traditional large
gear plate is reduced, it can meet the object of outlook
beautification.
[0005] As shown in FIG. 1, wherein one example for the patent of
U.S. Pat. No. 5,474,148 adapts the torsion sensing apparatus of
absolute angular displacement. The major mechanisms of this torsion
sensing apparatus are: stepping force directly drives the
unidirectional device 42 by crank axle 28, the power is transmitted
to the planet arm 44 of a planet gear set by unidirectional device
42, and finally power is output by the ring gear 46 connected with
large gear plate of bicycle, wherein the sun gear is connected to
sensor. For a planet gear system, at the situation of uniform
speed, since larger the stepping force is, larger the torsion input
to planet arm 44 is, so when sun gear 45 is connected to an elastic
body, i.e. the torsion value of sun gear 45 may be transferred into
the absolute angular displacement of elastic body. Since the
absolute angular displacement is proportional to stepping force, so
it may control the power output of driving motor. However, since
this prior art needs use of many sets of complicated parts of
planet gears and umbrella gears, etc, so not only the structure is
complicated, but also the costs of parts manufacture and assembly
are relatively higher. Additionally, since the driving motor of
U.S. Pat. No. 5,474,148 outputs the power to large gear plate to
drive wheels through ring gear 46, so driving motor also influences
the torsion value of sun gear 45 as power is output. Namely, if the
influence of stepping force of rider on torsion value of sun gear
is firstly overcome over (or larger than) that of driving motor,
then the driving motor will continue to output power. So the power
output of prior art is slower, and can not respond instantly to the
rider's power requirement. Additionally, in prior art, since the
planet arm 44 is used to transmit power to wheels by rotating the
ring gear 46, so the reducing speed of this device is larger, and
U.S. Pat. No. 5,474,148 also applies such device to proceed the
task of reducing speed of rotation speed of driving motor. However,
when the rider does not use the driving motor to output power (i.e.
battery is out of power), the rider will step more rounds to make
the crank axle 28 drive the wheel to move and it causes lots of
inconveniences.
[0006] There is another prior art example for applying absolute
angular displacement method as torsion sensing apparatus. The power
transmission of driving motor and stepping force sensing are
proceeded mainly by the connection transmission of multi-sets of
differential umbrella gear set. Besides its shortcoming is the cost
increase caused by the application of multi-sets of differential
umbrella gear set, its main shortcoming is focused on the crank
axle that is directly connected and actuated with the large gear
plate by the unidirectional umbrella gear ratchet. So, when the
driving motor can not output power, the crank axle and the large
gear plate rotate synchronously with one to one speed ratio. This
sort of application lacks flexibility.
[0007] Another prior art example is to apply the axle direction
displacement method as torsion sensing apparatus. Its torsion
sensing method is mainly comprised by stepping force to drive a
screw through crank axle. As the screw is rotating, it will cause a
displacement along nut axle direction for the screw and also press
down the spring located between screw and nut. Finally the nut
outputs the power to gear plate through unidirectional device.
Therefore by the magnitude of elastic coefficient of spring, the
ratio between the value of stepping force and axle direction
displacement of screw can be determined. So the stepping force
value can be known just by sensor to measure the magnitude of axle
direction displacement of screw. The shortcoming of this prior art
is that the match between screw and nut is easily interfered by the
external objects or fragment generated by the operation of parts of
itself. They may further be jammed seriously between screw and nut
to make the stepping force sensing become inaccurate. Furthermore,
when there is no power output from the driving motor, the crank
axle and gear plate of patent of patent no. 288427 could only
synchronously rotate with one to one speed ratio and that is of
less flexibility in real application.
[0008] Another kind of prior art example is applying axle direction
displacement method as torsion sensing apparatus. Its torsion
sensing method is mainly by stepping force to drive a torsion rod
through crank axle. Because the skew planes structure among the
torsion rods, it causes an axle direction displacement for the
torsion rod. This displacement is further magnified from rod to
rod. Therefore, the value of stepping force is known by measuring
the magnified axle direction displacement of lever. The
shortcomings of this prior art are that besides the structure is
more complicated and the cost is higher, also the sensing accuracy
is easily interfered by the fragment generated by the
above-mentioned parts of itself and crank axle and gear plate can
only synchronously rotate with one to one speed ratio.
SUMMARY OF THE INVENTION
[0009] The main object of the present invention is to provide an
auxiliary-bicycle torsion sensing and large gear plate minimization
apparatus, which has the merits of simple structure, lower
manufacture cost, accurate stepping force sensing for rider, less
interference by parts fragment, and design flexibility enhanced by
application of different rotation speed between the crank axle
stepped by rider and the large gear plate. These merits will
overcome the shortcomings of prior arts. And the minimization of
large gear plate may promote the outlook beautification of
auxiliary-bicycle.
[0010] Another object of the present invention is to provide an
auxiliary-bicycle torsion sensing apparatus, wherein the torsion of
stepping force of rider is transmitted by the swing arm of planet
gear system and the absolute angular displacement of swing arm is
measured by a sensing apparatus to further control the driving
apparatus to output power to drive the wheels to rotate. This
arrangement has the advantages of simple structure, low manufacture
cost, accurate stepping force measurement, and instant accurate
responding rider's stepping force magnitude from the power output
of driving apparatus, etc. And the minimization of large gear plate
for auxiliary-bicycle may meet the object of outlook
beautification.
[0011] To achieve above-mentioned objects, an auxiliary-bicycle
torsion sensing apparatus of the present invention at least
includes a sun gear, a unidirectional device, a planet gear set, a
second planet gear, and a sensing apparatus. The auxiliary-bicycle
torsion sensing apparatus is provided for arranging at transmission
apparatus of auxiliary-bicycle. The transmission apparatus at least
includes a crank axle, a gear plate and speed-variation gear set.
The power output of a driving apparatus may be controlled by the
rotation of crank axle. The power output of driving apparatus can
drive gear plate to rotate through the transmission of transmission
apparatus.
[0012] The sun gear of the auxiliary-bicycle torsion sensing
apparatus is fixed on the crank axle and driven to rotate with the
crank axle. The planet gear set at least includes a swing arm and a
first planet gear. The swing gear is pivotally arranged on the
crank axle by pivotal rotation method. The first gear is pivotally
arranged on the swing arm and driven to rotate together with the
sun gear. The first planet gear may be driven to rotate by the
rotation of crank gear. And the swing arm further generates a
rotation torsion of upward rotation which is same as that of the
sun gear. The sensing apparatus is connected to one side of the
swing arm, which can measure the rotation torsion of the swing arm
and generates a sensing signal to control the power output of the
driving apparatus. The unidirectional device is connected to the
gear plate and can proceed single direction transmission. The
second planet gear is arranged on the planet gear set and driven
together with the first planet gear. The second gear is driven
together with the unidirectional device. And the single
transmission direction of unidirectional device can make the second
planet gear drive gear plate to rotate, but gear plate can not
drive the second planet gear to rotate.
[0013] In a preferable embodiment, the auxiliary-bicycle torsion
sensing apparatus further includes a medium gear and a ring gear.
The medium gear matches with the second gear and the ring gear
matches with both medium gear and unidirectional device. And the
sensing apparatus includes a pushing pillar, a replacement element,
a pushing block, and a stress sensor. One end of the pushing pillar
pushes against the swing arm. Another end is connected with the
stress sensor. The pushing pillar may transfer the rotation torsion
of the swing arm to stress sensor. The pushing block is pushing
against the swing arm. The replacement element is connected to the
pushing pillar. An elastic force may be provided to make the
pushing pillar maintain a predetermined position under the state of
no external force.
[0014] Preferable, the speed-variation gear set is comprised of
several matching multi-level gears.
[0015] Preferable, the driving apparatus is a electric driving
motor.
[0016] For your esteem review committee member to further
understand and recognize the present invention, in accordance with
several drawings a detailed description is presented as
following.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is an illustration for the prior auxiliary-bicycle
torsion sensing apparatus.
[0018] FIG. 2 is a preferable embodiment illustration for the
auxiliary-bicycle torsion sensing apparatus of the present
invention.
[0019] FIG. 3 is an A-A section view illustration for FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] One characteristic of the auxiliary-bicycle tension sensing
and large gear plate minimization apparatus is a planed gear set
that is arranged inside the transmission apparatus of an
auxiliary-bicycle. Wherein the sun gear of the planet gear set is
connected to the crank axle of the auxiliary-bicycle and directly
driven together with it. And the stepping force of the crank axle
is then output to the gear plate of the auxiliary-bicycle through
the transmission of both sun gear and planet gear. Also, one side
of the swing arm of the planet gear set (i.e. the connection arm
used to pivotally arrange both sun gear and planet gear) arranges
with a stress sensor. When the crank axle is rotated by the
stepping force of rider, the swing arm would generate a rotation
torsion, the power output of the driving motor is controlled by the
torsion value sensed by the stress sensor. Because the present
invention only adapts with single-level planet gear set to achieve
the functions of power transmission and torsion detection, the
structure of application parts is simple and manufacture cost is
low. And the metal ashes or external objects further won't
influence the sensing accuracy. Furthermore, the sensing method of
the present invention applies the tangent force component of the
rotation of the sun gear (i.e. crank axle) to make the swing arm
generate rotation torsion, just only does the rider step on the
crank axle, instantly may the output power of driving motor be
obtained. Compared with the prior art, the present invention may
more directly, more instantly and more accurately fulfill the
requirement of motor power. Additionally, because the crank axle of
the present invention is not directly connected and driven with the
large gear plate of the auxiliary-bicycle, but the power of the
crank axle is output to the large gear plate through the matching
transmission of both sun gear and planet gear. So, when there is no
power output from the driving motor, the rotation ratio between the
crank axle and large gear plate is not absolutely the relationship
of one to one but determined by gear tooth number ratio between the
sun gear and planet gear. So, the auxiliary-bicycles with different
rotation speed ratio may further be designed out to make the
present invention may be applied to broader scopes.
[0021] A detailed description for an auxiliary-bicycle torsion
sensing and large gear plate minimization apparatus of one
preferable embodiment of the present invention, in accordance with
detailed structure, motion manners, function and other
characteristic, is presented as following.
[0022] Please refer to FIG. 2 and FIG. 3, which show one preferable
embodiment of auxiliary-bicycle torsion sensing apparatus of the
present invention. Wherein, FIG. 2 is a preferable embodiment
illustration for the auxiliary-bicycle torsion sensing apparatus of
the present invention. FIG. 3 is an A-A section view illustration
for FIG. 2.
[0023] An auxiliary-bicycle torsion sensing apparatus 8 of the
present invention is provided and arranged at a transmission
apparatus 7 of auxiliary-bicycle. The transmission apparatus 7 at
least includes a crank axle 71, a gear plate 72 (large gear plate)
and a speed-variation gear set 73. The power output of a driving
apparatus 6 is controlled by the rotation of the crank axle 71. The
power output of the driving apparatus 6 may drive the gear plate 72
to rotate through the transmission of the transmission apparatus 7.
In the preferable embodiment of the present invention, the driving
apparatus 6 is an electric driving motor. The speed-variation gear
set 73 is a speed-reduction gear set that is comprised by several
matching multi-level gears 731, 732. Its speed reduction is
dependent on the power output rate and rotation speed of the
driving apparatus 6 (driving motor) and multi-level gear 731, 732
with different level number and different matching gear number is
designed out. So, the design of rotation speed and torsion of the
gear plate 72 may fulfill the requirement of the rider as he really
drives the auxiliary-bicycle.
[0024] Since the element mechanism or apparatus of the described
auxiliary-bicycle of the present invention, such as: detailed
structure, arrangement position of the transmission apparatus 7,
driving apparatus 6 (electric driving motor) and its source and
control circuit, gear plate 72 with transmission mechanism of chain
or wheel, etc., and crank axle 71 with detailed structure of
treadle, etc. are the all technique belonged to prior art and not
technique characteristic requirement of the present invention. So
the detailed structure and actuation methods are not described
repetitiously in following. The relevant material may be referred
from the content of prior art described in the background of
invention of the present patent application.
[0025] The characteristics of the present invention are the
auxiliary-bicycle torsion sensing apparatus 8 and its connection
relationship and actuation methods with the crank axle 71 and
multi-level gear 732. The auxiliary-bicycle torsion sensing
apparatus 8 includes: a sun gear 81, a unidirectional device 82, a
planet gear set 83, a medium gear 84, a gear 85, and a sensing
apparatus 86.
[0026] The sun gear 81 of the auxiliary-bicycle sensing apparatus 8
is fixed at crank axle 71 and directly driven synchronously to
rotate. The planet gear set 83 at least includes a swing arm 832, a
first planet gear 831, and a second planet gear 833. The swing arm
832 is pivotally arranged at the crank axle 71 by pivotal rotation
method. The first planet gear 831 is pivotally arranged at the
swing arm 832 and matched with the sun gear 81. The first planet
gear 831 is driven to rotate by the rotation of the crank axle 71.
And, when the sun gear 81 rotates, its tangent force component may
make the swing arm 832 generate a rotation torsion with upward
rotation direction which is same as that of the sun gear 81. The
sensing apparatus 86 is connected to one side of the swing arm 832
(preferably arranged at the side of rotation direction of the swing
arm) to sense the rotation torsion of the swing arm 832 and
generates a sensing signal to provide and control power output for
the driving apparatus 6.
[0027] The second planet gear 833 is arranged at the planet gear
set 82 and connected with the first planet gear 831 in same axle
and rotated synchronously. The second planet gear 833 is matched to
a medium gear 84, while ring gear 85 is matched with medium gear 84
and unidirectional device 82 to proceed transmission. So, the
second planet gear 833 may connect and actuate with the
unidirectional device 82. Wherein, the unidirectional device,
preferably a unidirectional ratchet device, is connected with the
gear plate 72 by an axle sleeve 87 and may rotate synchronously
with the gear plate 72. Since the said unidirectional device 82 is
a prior technique, so its detailed structure is not described here
repetitiously. And, the single direction transmission of the
unidirectional device 82 makes the second planet gear 833 may
actuate the gear plate 72 to rotate, but the gear plate 72 can not
actuate the second planet gear 833 to rotate (it will rotate idly).
Also, since the crank axle 71 of the present invention is not
directly actuated with the large gear 72 of the auxiliary-bicycle
but the power of the crank axle 71 is output to the large gear
plate 72 by the matching transmission between the sun gear 81 and
the planet gears 831, 832, so when there is no power output from
the driving motor 6 (e.g. when the rider intends to use the
auxiliary-bicycle as ordinary bicycle, or when the battery lacks
electricity to make the power output of the driving apparatus 6 be
insufficient), the rotation speed ratio between the crank axle 71
and the large gear plate 72 is determined by the gear tooth number
ratio between the sun gear 82 and the planet gear 831, 832, and
medium gear 84. If the manufactures of auxiliary-bicycle intend to
design out a faster auxiliary-bicycle appropriate for the ordinary
plain riders (e.g. the metropolitan consumers), the manufactures
only need to change the rotation ratio between the crank axle 71
and the large gear plate 72 to be smaller than the value of one,
then when the rider steps one round of the crank axle, the driving
effect of several round of rotation for the gear plate 72 will be
generated, so the auxiliary-bicycle can be ridden very faster even
when there is no motor power output, and there is completely no
need to change the speed reduction ratio of other transmission
apparatus 7 or output rate of the driving motor. While the
manufactures intends to design out an auxiliary-bicycle for
leisurely riding appropriately for the rider in ordinary uphill and
downhill road (e.g. the consumers living in country or mounds), the
rotation ratio between the crank axle 71 and the large gear plate
72 can be made to be larger than one. Now, the rider needs to step
several rounds to drive the gear plate 72 to rotate one round, and
the riding is more energy-saving and appropriate for uphill road,
however the design is complete no need to change the mechanism or
speed reduction ratio of other transmission apparatus.
[0028] Wherein, among the speed-variation gear set 73 one
multi-level gear 732 is matched and actuated with the
unidirectional device 82 to make the speed-variation gear set 70
connected and actuated to the gear plate 72 also through the
transmission of the unidirectional device 82. And the
speed-variation gear set 73 may actuate the gear plate 72 to rotate
through the transmission of the unidirectional device 82, but the
gear plate can not actuate the speed-variation gear set 82 and also
the crank axle 72 to rotate (they will rotate idly). Therefore,
when the output power of the driving apparatus 6 drives the gear
plate 72 to rotate, it also completely won't influence the torsion
value of the swing arm 832. So, when the rider needs larger power,
he just greatly steps down the crank axle 71 to rotate, the torsion
sensing apparatus 86 instantly senses the variation of this torsion
value and simultaneously controls the driving apparatus to output
larger power. This sense of torsion is direct, instant and accurate
to overcome the prior art's shortcoming that is caused by the
torsion sense must first overcome the output power of the driving
apparatus.
[0029] In the present preferable embodiment, the sensing apparatus
86 includes a pushing pillar 861, a stress-sensing device 862, a
replacement element 863, and a pushing block 88. One end of the
pushing pillar 861 pushes against the side of the rotation
direction of swing arm 832. Another end of the pushing pillar is
then connected with a stress-sensing device 862. The pushing pillar
861 may convert the rotation absolute angular displacement of the
swing arm into a linear displacement and transmits the rotation
torsion of the swing arm to the stress-sensing device 862.
According to the sensed torsion value (or the electric potential
difference caused by the corresponding variation), the
stress-sensing device 862 generates a sensing signal to control the
power output of the driving apparatus 6. The pushing block 88
pushes against the side opposite to the rotation direction of the
swing arm 832 and positions it. The replacement element 863 (a
compressed spring is preferable) connects to the pushing pillar 861
and under the state of no external force (when the rider does not
step down the treadle) may provide a elastic force to make the
pushing pillar 861 push the swing arm 832 back to original
position. (13)
[0030] Of course, at appropriate positions of the torsion sensing
apparatus 8 and the transmission apparatus 7 of the
auxiliary-bicycle of the present invention, several bearings 74a,
74b, 74c, 74d, and 74e, etc are arranged, so several adjacent
elements may proceed relatively sliding and rotating. Since the
structure and arrangement positions of bearings 74a, 74b, 74c, 74d,
and 74e are not the technique characteristics of the present
invention and are well-known designs to those who skill such
transmission mechanism, so they are not repetitious here.
[0031] Because the present invention only adapts with single-level
planet gear set 83 to achieve the functions of power transmission
and torsion sensing, the number of parts is less and the structure
of application parts is simple and manufacture cost is low. And
relative to the prior art using screws and nuts, the metal ashes or
external objects further won't influence the sensing accuracy.
Furthermore, the sensing method of the present invention applies
the tangent force component of the rotation of the sun gear 81
(i.e. crank axle 71) to make the swing arm 832 generate rotation
torsion, just only does the rider step on the crank axle 71,
instantly may the output power of driving motor be obtained.
Compared with the prior art, the present invention may more
directly, more instantly and more accurately fulfill the
requirement of motor power. Additionally, because the crank axle 71
of the present invention is not directly connected and driven with
the large gear plate 72 of the auxiliary-bicycle, but the power of
the crank axle 71 is output to the large gear plate 72 through the
matching transmission of both sun gear 81, planet gear 831, 832 and
medium gear 84. So, when there is no power output from the driving
motor, the rotation ratio between the crank axle 71 and large gear
plate 72 is not absolutely the relationship of one to one but
determined by gear tooth number ratio between the sun gear and
planet gear. So, the auxiliary-bicycles with different rotation
speed ratio may further be designed out to make the present
invention may be applied to broader scopes. Also the present
invention first makes the stepping speed increase through design,
then reduces the size of traditional large gear plate to further
achieve the object of outlook beautification and overcome the
shortcomings: the large gear plate of traditional bicycle is too
large, during covering transmission chain, covering volume is too
big and outlook is disgraceful.
[0032] While the invention has been described in terms of a
preferred embodiment, various alternatives and modifications can be
devised by those skilled in the art without departing from the
invention. Accordingly, the present invention is intended to
embrace all such alternatives that fall within the scope of the
claims.
* * * * *