U.S. patent application number 11/856021 was filed with the patent office on 2009-03-19 for torsional force transmitting apparatus.
Invention is credited to Shu-Xia Liao, Chong-Liang Lin.
Application Number | 20090075535 11/856021 |
Document ID | / |
Family ID | 40454982 |
Filed Date | 2009-03-19 |
United States Patent
Application |
20090075535 |
Kind Code |
A1 |
Lin; Chong-Liang ; et
al. |
March 19, 2009 |
Torsional Force Transmitting Apparatus
Abstract
The present invention aims to couple a propeller with a power
output shaft to transmit the torsional force of the power output
shaft to the propeller. The apparatus includes a first sleeve and a
second sleeve that form a coupling surface between them to hold a
torsional force transfer means. The torsional force transfer means
is coupled with the first sleeve and the second sleeve to transmit
only a selected amount of the torsional force. The first sleeve has
a first outer surface and the second sleeve has a second inner
surface that are engaged respectively with the propeller and the
power output shaft in the rotating direction so that the power
output shaft can transmit the torsional force to the propeller. In
the event that the propeller is overloaded the torsional force
transfer means between the first sleeve and the second sleeve slip
to form a protection mechanism.
Inventors: |
Lin; Chong-Liang; (Taichung,
TW) ; Liao; Shu-Xia; (Tanzi Shiang, TW) |
Correspondence
Address: |
APEX JURIS, PLLC
12733 LAKE CITY WAY NORTHEAST
SEATTLE
WA
98125
US
|
Family ID: |
40454982 |
Appl. No.: |
11/856021 |
Filed: |
September 15, 2007 |
Current U.S.
Class: |
440/64 |
Current CPC
Class: |
B63H 23/34 20130101 |
Class at
Publication: |
440/64 |
International
Class: |
B63H 5/07 20060101
B63H005/07 |
Claims
1. A torsional force transmitting apparatus to transmit a torsional
force of a power output shaft to a propeller, comprising: a first
sleeve which has a first inner surface and a first outer surface
which is engaged with the propeller in a rotational direction; a
second sleeve which has a second inner surface and a second outer
surface, the second inner surface being engaged with the power
output shaft in the rotational direction, the first inner surface
and the second outer surface being coupled together in a rotary
manner to form a coupling surface; and a torsional force transfer
means located on the coupling surface to couple the first sleeve
and the second sleeve and transmit only a selected amount of the
torsional force.
2. The torsional force transmitting apparatus of claim 1, wherein
the torsional force transfer means is formed by disposing an
adhesive on the coupling surface; the amount of the torsional force
transmittable being controlled by changing the type and bonding
size of the adhesive.
3. The torsional force transmitting apparatus of claim 1, wherein
the torsional force transfer means is formed by carving at least
one flute on the coupling surface between the first inner surface
and the second outer surface to allow an elastic element to be
wedged in, the second sleeve having two ends to hold respectively a
upper pad and a lower pad that are bonded to the first sleeve to
prevent the first sleeve and the second sleeve from sliding against
each other to anchor the elastic element, the amount of the
torsional force transmittable being controlled by changing the
number of the flute.
4. The torsional force transmitting apparatus of claim 3, wherein
the elastic element includes a rubber strut coupling with a
spring.
5. The torsional force transmitting apparatus of claim 3, wherein
the upper pad and the lower pad are made from rubber, and formed at
a dimension slightly larger than an inner diameter of the
propeller.
6. The torsional force transmitting apparatus of claim 1, wherein
the first outer surface of the first sleeve is encased by an
elastic material.
7. The torsional force transmitting apparatus of claim 6, wherein
the elastic material is rubber.
8. The torsional transmission apparatus of claim 6, wherein the
elastic material is plastics.
9. The torsional force transmitting apparatus of claim 1, wherein
the first outer surface is non-circular and the propeller has a
corresponding non-circular profile.
10. The torsional force transmitting apparatus of claim 1, wherein
the second inner surface has annular inner teeth and the power
output shaft has annular outer teeth corresponding to the annular
inner teeth to be coupled together for installation such that the
annular inner teeth and the annular outer teeth are engaged to
allow the power output shaft to transmit the torsional force to the
second sleeve.
11. The torsional force transmitting apparatus of claim 1, wherein
the first outer surface has a plurality of ribs and the propeller
has an inner hole formed in a shape corresponding to the first
outer surface, the propeller and the first sleeve being interposed
by a plurality of elastic struts on one side of the ribs.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a torsional force
transmitting mechanism and particularly to a torsional force
transmitting apparatus for propellers to provide overload
protection.
BACKGROUND OF THE INVENTION
[0002] A torsional force transmitting apparatus aims to couple a
propeller with a power output shaft. When a boat sails the
propeller might hit unknown objects such as reefs. Such an incident
could generate an excessive load torsional force and result in
breaking or damage of the propeller, engine and gear box. To
protect the propeller, engine and gear box, the torsional force
transmitting apparatus ought to be slipping or broken. By replacing
the torsional force transmitting apparatus with a new one the boat
can sail again. Such an approach can save repair cost and time.
[0003] However, the conventional torsional force transmitting
apparatus used on a propeller is formed by squeezing a round rubber
into a round inner hole of the propeller through a press. By
controlling the compressed amount of the rubber a positive force to
the round inner hole of the propeller is provided. And by
controlling the amount of the positive force the amount of
torsional force that can be transmitted by the rotating propeller
can be determined. In the event of overloading, and slipping or
breaking occurs, a protection mechanism is formed. But such an
approach has to rely on the press to perform replacement and
repairs when damage occurs. And the replacement and repairs have to
be done at a professional repair shop. Moreover, the positive force
provided by the rubber highly depends on temperature. Used on a
high horsepower engine, the temperature rises easily and the rubber
becomes soft and results in slipping. At a lower temperature the
rubber becomes harder, the protection effect diminishes.
[0004] U.S. Pat. No. 4,566,855 discloses another torsional force
transmission apparatus for propellers. It has a rubber-made
resilient shock mount sleeve with the outer perimeter formed in a
gear shape to mate an inner hole of a propeller and an inner hole
formed in another gear shape to mate the outer perimeter of a
spline driver sleeve adaptor. By controlling the depth of the gear,
a positive force is generated by deformation of the rubber when the
resilient shock mount sleeve rotates that is used to transmit the
torsional force. Namely the depth of the gear can determine the
amount of a load torsional force, thereby control the transmitting
torsional force to produce slipping. Such a technique does not do
installation by compaction, hence does not require a press to do
replacement when damage occurs. Users can do repairs by themselves
if desired. But due to the rubber is installed without being
compressed in advance, and only the teeth of the gear are
compressed during rotation, the compressed amount is little. Hence
the transmitting torsional force also is limited. It is not
suitable for a high power engine system.
[0005] U.S. Pat. No. 5,322,416 discloses yet another technique
which has the resilient shock mount sleeve made from plastics. The
outer perimeter of the resilient shock mount sleeve and the inner
hole of the propeller are formed respectively in an octagonal
shape. The resilient shock mount sleeve has an inner hole and the
drive sleeve has an outer perimeter that are formed respectively in
a gear shape. The resilient shock mount sleeve generates a positive
force resulting from deformation during rotation to transmit the
torsional force. It also is not installed by compaction and can be
repaired by the users. As the material is switched to plastics, a
smaller compression amount can transmit a greater torsional force.
Hence it can be used on a higher power engine system. In the event
that impact of an external force occurs that exceeds the torsional
load, the plastics fracture to provide a protection mechanism. But
the plastics still highly depend on temperature. Use in an
environment of a lower temperature, it is hardened and might not
break even under the impact of an estimated breakable torsional
force. As a result, damages of the propeller, engine and gear box
could occur. Moreover, when the rotational direction of the
propeller is switched the contact surface of the resilient shock
mount sleeve and the propeller also changes. During switching a
great deal of noise and shock are generated due to no buffer is
provided.
SUMMARY OF THE INVENTION
[0006] Therefore the primary object of the present invention is to
provide a torsional force transmitting apparatus that is not easily
affected by temperature and generates less noise and shock.
[0007] The torsional force transmitting apparatus of the invention
aims to be used on propellers to couple a propeller with a power
output shaft to transmit the torsional force of the power output
shaft to the propeller. It includes a first sleeve, a second sleeve
and a torsional force transfer means. The first sleeve has a first
inner surface which is coupled with a second outer surface of the
second sleeve in a rotary manner to form a coupling surface. The
torsional force transfer means is located on the coupling surface.
The torsional force transfer means connects the first sleeve and
the second sleeve, and can transmit only a selected amount of the
torsional force. The first sleeve has a first outer surface and the
second sleeve has a second inner surface that are engaged
respectively with the propeller and the power output shaft in the
rotating direction.
[0008] By means of the construction set forth above, the selected
amount of torsional force transmittable can be controlled through
the torsional force transfer means. When the torsional force of the
power output shaft is transmitted to the propeller, and the
propeller hits a unknown object and results in significant increase
of the torsional force and overloaded, the torsional force transfer
means between the first sleeve and the second sleeve breaks and
loosens, hence the first sleeve and the second sleeve rotate idly
to provide protection for the propeller, engine and gear box.
[0009] The foregoing, as well as additional objects, features and
advantages of the invention will be more readily apparent from the
following detailed description, which proceeds with reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is an exploded view of the invention.
[0011] FIG. 2 is a cross section of the invention in a use
condition.
[0012] FIG. 3 is an exploded view of another embodiment of the
invention.
[0013] FIG. 4 is a fragmentary cross section of yet another
embodiment of the invention.
[0014] FIG. 5 is a fragmentary cross section of still another
embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] Please refer to FIGS. 1 and 2, the torsional force
transmitting apparatus according to the invention aims to transmit
the torsional force of a power output shaft 10 to a propeller 20.
It includes a first sleeve 30A, a second sleeve 40A and a torsional
force transfer means 50A. The first sleeve 30A has a first inner
surface 31 and a first outer surface 32 which is non-circular. The
propeller 20 also is formed in a non-circular profile such that the
second outer surface 32 can be engaged with the propeller 20 in the
rotating direction.
[0016] The second sleeve 40A has a second inner surface 41 and a
second outer surface 42. The second inner surface 41 has annular
inner teeth 43 formed thereon. The power output shaft 10 has
annular outer teeth 11 mating the annular inner teeth 43 so that
they can be coupled and installed together with the second inner
surface 41 engaging with on the power output shaft 10 in the
rotational direction. The power output shaft 10, through the mutual
engagement of the annular inner teeth 43 and the annular outer
teeth 11, can transmit the torsional force to the second sleeve
40A.
[0017] The first inner surface 31 of the first sleeve 30A and the
second outer surface 42 of the second sleeve 40A are coupled
together in a rotary manner to form a coupling surface 35. The
torsional force transfer means 50A is located on the coupling
surface 35 by disposing an adhesive 36 onto the coupling surface
35. By changing the type and size of the bonding surface of the
adhesive 36 the amount of the torsional force transmittable can be
controlled. Hence the torsional force transfer means 50A which
couples the first sleeve 30A and the second sleeve 40A can transmit
only a selected amount of the torsional force.
[0018] By means of the construction set forth above, when the power
output shaft 10 is engaged with the propeller 20, and the propeller
20 hits an unknown object and results in great increase of the
torsional force and overloaded, the torsional force transfer means
50A breaks down so that the first sleeve 30A and the second sleeve
40A rotate idly. As a result breaking of the propeller 20 can be
prevented. And the engine and gear box also are protected.
[0019] Refer to FIG. 3 for another embodiment of the invention. It
has a torsional force transfer means 50B located on the coupling
surface 35 between the first inner surface 31 of a first sleeve 30B
and the second outer surface 42 of a second sleeve 40B. The
coupling surface 35 has at least one flute 44 formed thereon to
hold an elastic element 45. The flute 44 is evenly spaced on the
coupling surface 35. The elastic element 45 includes a rubber strut
451 coupling with a spring 452. The second sleeve 40B has two ends
holding respectively a first pad 46 and a second pad 47. The first
sleeve 30B runs through the second sleeve 40B. After the elastic
element 45 is wedged in the flute 44, the upper pad 46 and the
lower pad 47 are bonded to the first sleeve 30B, thereby to prevent
the first sleeve 30B and the second sleeve 40B from sliding against
each other and anchor the elastic element 45. In the event that the
torsional force between the first sleeve 30B and the second sleeve
40B is excessive, the elastic element 45 is compressed and deforms,
and an idle rotation occurs between the first sleeve 30B and the
second sleeve 40B. By changing the number of the flute 44, the
torsional force transmittable can be controlled. The upper pad 46
and the lower pad 47 may be made from rubber. The upper pad 46 and
the lower pad 47 are formed at a dimension slightly larger than the
inner diameter of the propeller 20. Hence when the first sleeve 30B
is engaged with the propeller 20 through the upper pad 46 and the
lower pad 47 in the rotational direction a shock absorbing effect
can be achieved to reduce noise and vibration during rotation of
the propeller 20.
[0020] Refer to FIG. 4 for yet another embodiment of the invention.
The second outer surface 32 of a first sleeve 30C is encased by an
elastic material 60 which may be rubber or plastics. The first
sleeve 30C and the propeller 20 are engaged through the elastic
material 60. Such a structure also can absorb shock to reduce noise
and shock during rotation of the propeller 20.
[0021] Refer to FIG. 5 for still another embodiment of the
invention. The second outer surface 32 of a first sleeve 30D has a
plurality of ribs 321. The inner hole of the propeller 20 has a
corresponding shape. Moreover, there are a plurality of elastic
struts 70 on one side of the ribs 321 to be interposed between the
propeller 20 and the first sleeve 30D. The first sleeve 30D is in
contact with the propeller 20 through the elastic struts 70.
Therefore a shock absorbing effect can be achieved to reduce noise
and shock during rotation of the propeller 20.
[0022] As a conclusion, the present invention provides torsional
force transfer means 50A and 50B between the first sleeves 30A and
30B and second sleeves 40A and 40B. The torsional force transfer
means 50A and 50B can transmit only a selected amount of torsional
force, thus form a protection mechanism. Thereby it can protect the
more expensive propeller 20 or the engine and gear box coupling
with the power output shaft 10. By selecting varying types and
bonding sizes of the adhesive 36 or changing the number of the
flute 44, the transmittable torsional force can be controlled to
suit different types of propeller 20. In the event of damage, due
to the first sleeves 30A and 30B, the second sleeves 40A and 40B,
and the propeller 20 are not engaged by compaction in the axial
direction, replacement can be done easily to meet user's
requirements.
* * * * *