Propeller assembly

Description

BACKGROUND OF THE INVENTION

The invention relates generally to marine engines, and more particularly, to propeller hubs.

Outboard engines include a drive shaft extending from an engine power head, through an exhaust case, and into an engine lower unit. The lower unit includes a gear case, and a propeller shaft extends through the gear case. Forward and reverse gears couple the propeller shaft to the drive shaft. The drive shaft, gears, and propeller shaft sometimes are referred to as a drive train.

A propeller is secured to and rotates with the propeller shaft. Torque from the propeller is transmitted to the shaft. Specifically, propeller hub assemblies transmit torque to the propeller shaft. Exemplary propeller hub assemblies include cross bolts, keys, shear pins, plastic hubs, and compressed rubber hubs.

Such hub assemblies should have sufficient strength or stiffness so that during normal engine operations, very few losses occur between the propeller shaft and the propeller. Such hub assemblies, however, also should be resilient so that the engine drive train is protected in the event of an impact, e.g., if the propeller hits a log or rock. Further, since engine manufacturers often utilize different propeller shaft arrangements, it would be desirable to provide propeller hub assemblies that facilitate use of one propeller on engines of different engine manufacturers.

BRIEF SUMMARY OF THE INVENTION

In an exemplary embodiment, a propeller assembly includes an inner hub, an interchangeable drive sleeve that mates with the inner hub, a biasing member that biases the drive sleeve into contact with the inner hub, and a propeller including an outer hub in which the inner hub and drive sleeve are inserted. More particularly, the inner hub includes a plurality of teeth that mate with a corresponding plurality of drive sleeve teeth.

The drive sleeve includes a first body portion and a second body portion. The second body portion has a larger diameter than the first body portion and includes drive sleeve teeth. A bore extends through the drive sleeve, and a plurality of splines are in an inner diameter surface of the drive sleeve bore. The splines are configured to mate with a plurality of splines on a propeller shaft that extends through the bore.

The inner hub includes a plurality of drive keys that mate with a plurality of grooves in an inner surface of the outer hub. The inner hub teeth are at an end of the inner hub and mate with the drive sleeve teeth. The biasing member contacts the drive sleeve and biases the drive sleeve into contact with the inner hub such that rotation of the inner hub rotates with the drive sleeve.

The outer hub includes a cylindrical shaped body. A plurality of blades extend from an outer diameter surface of the outer hub body. An inner diameter surface of the outer hub body is shaped to mate with the inner hub drive keys to limit relative movement between the inner hub and the outer hub.

During operation, and upon the occurrence of an impact, the drive sleeve compresses the biasing mechanism and the drive sleeve teeth slip with respect to the inner hub teeth. Thus, the propeller shaft and drive sleeve are permitted to rotate with respect to the inner hub and propeller outer hub. The operational condition in which the drive sleeve teeth slip with respect to the inner hub teeth is sometimes referred to herein as the resilient operation mode.

The above described propeller assembly facilitates the easy replacement of the inner hub. Specifically, in the event that the inner hub needs to be replaced, a user simply removes the propeller assembly from the propeller shaft, and removes the drive sleeve and inner hub from within the outer hub. A replacement drive sleeve and/or inner hub can then be utilized when reassembling the propeller assembly and mounting the assembly on the propeller shaft.

Further, different drive sleeves can be provided so that the propeller can be utilized on many different types of marine engines. For example, one particular marine engine may have splines on the propeller shaft of a first length, and another particular marine engine may have splines on a propeller shaft of a second length. Different drive sleeves having different length splines on their inner diameter surfaces can be provided. Although different drive sleeves are utilized, a same propeller can be used. That is, by providing interchangeable drive sleeves, one propeller can be used in conjunction with many different type engines.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a front perspective view of a propeller assembly in accordance with one embodiment of the present invention.

FIG. 2

is an exploded view of the propeller assembly shown in FIG.

1

.

FIG. 3

is a rear perspective view of the propeller assembly shown in FIG.

1

.

FIG. 4

is an exploded view of the propeller assembly shown in FIG.

3

.

FIG. 5

is a side cross-sectional view of the propeller assembly shown in FIG.

1

.

FIG. 6

is another cross-sectional view of the assembly shown in FIG.

5

.

FIG. 7

is a cross-sectional view through line

7

—

7

shown in FIG.

6

.

FIG. 8

is a cut-away side view of the propeller assembly shown in FIG.

1

.

FIG. 9

is a cut-away side view of the propeller assembly shown in

FIG. 1

in the resilient mode.

FIG. 10

is a schematic view of the inner hub teeth engaged with the drive sleeve teeth shown in FIG.

2

.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is not limited to practice in connection with a particular engine, nor is the present invention limited to practice with a particular propeller configuration. The present invention can be utilized in connection with many engines and propeller configurations. For example, a propeller having three blades is described herein. The present invention, however, can be used in connection with propellers having any number of blades. Therefore, although the invention is described below in the context of an exemplary outboard engine and propeller configuration, the invention is not limited to practice with such engine and propeller.

FIG. 1

is a front perspective view of a propeller assembly

100

in accordance with one embodiment of the present invention. Propeller assembly

100

is configured for being secured to a propeller shaft

102

of a marine engine. Propeller assembly

100

includes a thrust washer

104

, a propeller

106

having an outer hub

108

and a plurality of blades

110

extending from an outer diameter hub surface

112

, a washer

114

, and a nut

116

which secures assembly

100

to propeller shaft

102

.

Generally, propeller assembly

100

rotates with propeller shaft

102

during normal operations. In the event of an impact, e.g., propeller

106

strikes an object in the water, propeller

106

may rotate relative to shaft

102

as described below in more detail to protect an engine drive train.

FIG. 2

is an exploded view of propeller assembly

100

. As shown in

FIG. 2

, assembly

100

also includes a drive sleeve

118

having a first portion

120

and a second portion

122

. A plurality of grooves

124

are in an inner diameter surface

126

of drive sleeve

118

. Second portion

122

has a larger outer diameter than first portion

120

and includes a plurality of teeth

128

that extend from an end

130

of second portion

122

. Drive sleeve

118

further includes a ledge

132

that extends between an outer diameter outer surface

134

of first portion

120

and an outer diameter outer surface

136

of second portion

122

. Ledge

132

is substantially perpendicular to an axis

138

of propeller shaft

102

. In an exemplary embodiment, drive sleeve

118

is fabricated from an extruded plastic.

Assembly

100

also includes an inner hub

144

. A plurality of keys

146

are formed on an outer diameter surface

148

of inner hub

136

. Keys

146

are shaped to tightly mate with outer hub

108

. Specifically, and in the embodiment shown in

FIG. 2

, inner hub

144

includes four keys

146

spaced by intermediate sections

150

. Inner hub

144

also includes a plurality of teeth

152

that extend from an end

154

thereof. Inner hub teeth

152

are complimentary to drive sleeve teeth

128

such that rotation of drive sleeve

118

causes rotation of inner hub

144

.

Outer hub

108

includes a bore

160

shaped so that inner hub

144

and keys

146

tightly fit within bore

160

. Bore

160

includes a plurality of keyways

162

that accommodate keys

146

. In addition, drive sleeve

118

has an outer diameter less than an inner diameter of bore

160

. Therefore, inner hub

144

fits tightly within outer hub

108

, while drive sleeve

118

rotates relative to outer hub

108

.

Assembly

100

further includes a biasing mechanism

170

that extends between washer

114

and drive sleeve second portion

122

. In one embodiment, biasing mechanism

170

extends between an end wall (not shown) of outer hub

108

and second portion

122

of drive sleeve

118

. Biasing mechanism

170

, in the particular embodiment illustrated in

FIG. 2

, is a helical spring

172

extending between and contacting ledge

132

and the outer hub end. In an alternative embodiment, biasing mechanism

170

is a resilient grommet that contacts drive sleeve

118

and the outer hub end.

Biasing mechanism

170

biases drive sleeve

118

into contact with inner hub

144

such that drive sleeve teeth

128

mesh with inner hub teeth

152

and inner hub

144

rotates with drive sleeve

118

. In the event of an impact, drive sleeve

118

will continue to rotate at a same speed while inner hub

144

and outer hub

108

slow, or stop, their rotation, as described below in greater detail. Inner hub

144

is fabricated from a material, such as brass, which provides frictional contact between inner hub teeth

152

and drive sleeve teeth

128

sufficient to drive outer hub

108

up to a preset load limit and permit inner hub teeth

152

and drive sleeve teeth

128

to rotate relative to each other above that preset load limit such that drive sleeve

128

rotates relative to outer hub

108

.

Outer hub

108

has a cylindrical shape and blades

110

extend from outer diameter surface

112

of outer hub

108

. As explained above, bore

160

is shaped to mate with inner hub outer diameter surface

148

to limit relative movement between inner hub

144

and outer hub

108

. Propeller

106

can be cast from aluminum, stainless steel, or other materials.

Propeller shaft

102

has a tapered section

174

for mating with thrust washer

104

, and a splined section

176

for mating with drive sleeve grooves

124

. Propeller shaft

102

also includes a threaded section

178

for engagement with nut

116

. Different engines may have different length splined sections, and as described below in more detail, by simply using a mating drive sleeve, one propeller (e.g., propeller

106

) can be used on such different engines.

FIG. 3

is a rear perspective view of propeller assembly

100

. To secure propeller

106

to propeller shaft

102

, an outer hub assembly is formed by inserting biasing mechanism

170

(shown in

FIG. 2

) and drive sleeve

118

(shown in

FIG. 2

) into outer hub bore

160

. Inner hub

144

is then inserted into outer hub bore

160

.

Thrust washer

104

, propeller

106

, and outer hub

144

(shown in

FIG. 2

) are then pushed over propeller shaft

102

so that propeller shaft

102

extends through and engages drive sleeve

118

. Washer

114

is then pushed over shaft

102

, and threaded nut

116

is tightened on shaft

102

to secure propeller

106

to shaft

102

. As shown in

FIG. 3

, nut

116

is tightened on propeller shaft

102

so that washer

114

is tightly secured against outer hub

108

.

FIG. 4

is an exploded view of propeller assembly

100

. As shown in

FIG. 4

, outer hub

108

includes an end

180

having an opening

182

therethrough. Washer

114

contacts end

180

. In addition, biasing member

170

contacts end

180

and is positioned between end

180

and drive sleeve ledge

132

. In the particular embodiment shown in

FIG. 4

, biasing member

170

is a spring

172

, such as a compression spring. Spring

172

includes a pair of ends that are closed and ground which provides better load transferring capability than a spring with open ends that are not ground.

FIG. 5

is a side cross-sectional view of propeller assembly

100

along inner hub intermediate sections

150

. An outer diameter of drive sleeve

118

and an outer diameter of inner hub intermediate sections

150

are substantially similar. In the embodiment shown in

FIG. 5

, drive sleeve

118

has a substantially uniform outer diameter that corresponds to the outer diameter of inner hub intermediate sections

150

. Drive sleeve

118

is sized to rotate within outer hub bore

160

without engaging keyways

162

(shown in FIG.

2

).

As shown in

FIG. 5

, drive sleeve

118

is biased into contact with inner hub

144

by spring

172

. Spring

172

extends between outer hub end

180

and drive sleeve ledge

132

. Spring

172

, drive sleeve

118

and inner hub

144

are maintained within outer hub

108

with washer

104

which contacts an end

188

of outer hub

108

and an end

190

of inner hub

144

. Washer

104

has a tapered inner surface

192

complimentary to propeller shaft tapered portion

174

such that a washer bore first end

194

has a first diameter and a washer bore second end

196

has a second diameter. The second diameter is greater than the first diameter.

FIG. 6

is a side cross-sectional view of propeller assembly

100

along inner hub keys

146

. An outer diameter of inner hub keys

146

is larger than an outer diameter of drive sleeve

118

. In the embodiment shown in

FIG. 6

, outer hub keyways

162

extend from first outer hub end

180

to second outer hub end

188

. Thrust washer

104

has a shape complimentary to a shape of propeller shaft

102

and is maintained in contact with outer hub first end

180

by nut

116

.

FIG. 7

is a cross-sectional view through line

7

—

7

shown in FIG.

6

. As shown in

FIG. 7

, spring

172

extends between drive sleeve first portion

122

and an outer hub inner surface

198

. Drive sleeve first portion

122

tightly fits against propeller shaft

102

and engages propeller shaft

102

via the spline arrangement described above.

FIG. 8

is a cut-away side view of propeller assembly

100

showing spring

172

forcing drive sleeve

118

into contact with inner hub

144

such that drive sleeve teeth

128

engage inner hub teeth

152

. The compression force of spring

172

is sufficient such that during normal operations, torque is efficiently transferred from propeller shaft

102

to propeller

106

through drive sleeve

118

and inner hub

144

and drive sleeve teeth

128

maintain engagement with inner hub teeth

152

.

FIG. 9

is a cut-away side view of propeller assembly

100

showing spring

172

in a compressed state such that drive sleeve teeth

128

do not engage inner hub teeth

152

. Drive sleeve teeth

128

and inner hub teeth

152

are configured to maintain engagement up to a preset torque, such as 1000 lbf. Above the preset torque, the configuration of teeth

128

and

152

causes drive sleeve

118

to move axially away from inner hub

144

such that drive sleeve teeth

128

do not engage inner hub teeth

152

and drive sleeve

118

rotates with respect to inner hub

144

. In one exemplary embodiment, spring

172

has the following characteristics.

Wire properties

d = 0.18 in

wire diameter

D = 1.6 in

mean spring diameter

G = 10 × 10

6

shear modulus

C = \frac{D}{d} C = 8.889

exemplary range of C is from 5 to 9

Calculation of spring force given a prescribed deflection

For a plain spring,

Ne = 0

end coils

Na = 45

number of active coils

Nt = Na

total coils

p = 0.35 in

pitch

Lo = p(Na) + d

free length, limit is 2 in

Lo = 1.755 in

Ls = d(Nt + 1)

solid length

Ls = 0.99 in

OD = \sqrt{D^{2} + (\frac{p^{2} - d^{2}}{π^{2}}) + d}

outside diameter of spring at solid length max := 2.23 in

OD = 1.783 in

δ = 0.35 in

prescribed deflection

Lo-Ls = 0.765 in > 2δ = 0.7 in

Fs = \frac{d^{4} G (δ)}{8 D^{3} Na}

spring force

Fs = 24.917 lbf

Shear stress calculations

Kw = \frac{4 C - 1}{4 C - 4} + \frac{0.615}{C}

stress factor

τs = Kw \frac{8 FsD}{{πd}^{3}}

Sut = 75000 psi

stainless steel 302 spring

Ssy = 0.35 Sut

n = \frac{Ssy}{τs}

n = 1.3

For a squared and ground spring

Ne = 2

end coils

Na = 4.5

number of active coils

Nt = Na + 2

total coils

p = 0.35 in

pitch

Lo = p(Na) + 2d

free length, limit is 2 in

Lo = 1.935 in

Ls = dNt

solid length

Ls = 1.17 in

OD = \sqrt{D^{2} + (\frac{p^{2} - d^{2}}{π^{2}}) + d}

outside diameter of spring at solid length max := 2.23 in

OD = 1.783 in

δ = 0.35 in

prescribed deflection

Lo-Ls = 0.765 in > 2δ = 0.7 in

Fs = \frac{d^{4} G (δ)}{8 D^{3} Na}

spring force

Fs = 24.917 lbf

Shear stress calculations

Kw = \frac{4 C - 1}{4 C - 4} + \frac{0.615}{C}

stress factor

τs = Kw \frac{8 FsD}{{πd}^{3}}

Sut = 75000 psi

stainless steel 302 spring

Ssy = 0.35 Sut

n = \frac{Ssy}{τs}

n = 1.3

RUBBER GROMMET AS SPRING

T = Breakaway torque

F

Rub

= Force on rubber grommet @ a given torque

R = Radius at which surfaces between brass extrusion and plastic part

make contact

μ = 0.35 θ = 20 deg T = 1000 ft lbf R = 0.78 in

F_{Rub} = \frac{- T (µcos (θ) - \sin (θ))}{R (\cos (θ) + µsin (θ))}

Equation derived from freebody diagram

F

Rub

= 190.641 lbf Force exerted on rubber grommet @ breakaway torque

CALCULATION OF SHAPE FACTOR AND

MAXIMUM STRESS FOR CONTINUOUS

LOADING

SF = Shape factor for rubber grommet (assuming grommet can expand

only in the outward direction

OD = Outer diameter on rubber grommet

ID = Inner diameter on rubber grommet

L = Length of rubber grommet @ free position

σ

comp

= Compressive stress on rubber grommet

σ

cont

= Stress for continuous loading @ 15% for 70 DURO A soft

Urethane in compression

η = Safety factor

OD := 1.8 in ID = 1.0 in L = 1.0 in σ_{cont} = 140 \frac{lbf}{{in}^{2}}

SF = (\frac{{OD}^{2} - {ID}^{2}}{4 (L) OD})

SF = 0.311 Shape factor for rubber grommet

CALCULATION OF PRELOAD AND

DEFLECTION DUE TO BREAKAWAY TORQUE

ON RUBBER GROMMET

P

pre

= Preload on rubber grommet (load @ installed)

δ

c

= Deflection due to preload (a percentage of length L depending on

preload desired)

A = Load area on rubber grommet

E

c

= Compressive modulus of elasticity for an 70 DURO A @ 15%

compression

δ

Rub

= Deflection on rubber grommet due to breakaway torque

L = Length of rubber grommet @ free position (value defined in previous

page)

σ_{comp} = \frac{4 F_{Rub}}{π ({OD}^{2} - {ID}^{2})}

σ_{comp} = 108.362 \frac{lbf}{{in}^{2}}

Compressive stress on rubber

n = \frac{σ_{cont}}{σ_{comp}}

n = 1.292

Safety factor for continuous loading

CALCULATION OF PRELOAD AND

DEFLECTION DUE TO BREAKAWAY TORQUE

ON RUBBER GROMMET

P

pre

= Preload on rubber grommet (load @ installed)

δ

c

= Deflection due to preload (a percentage of length L depending on

preload desired)

A = Load area on rubber grommet

E

c

= Compressive modulus of elasticity for an 70 DURO A @ 15%

compression

δ

Rub

= Deflection on rubber grommet due to breakaway torque

L = Length of rubber grommet @ free position (value defined in previous

page)

E_{c} = 933.33 \frac{lbf}{{in}^{2}} δ_{c} = 0.10 L

A = \frac{π}{4} ({OD}^{2} - {ID}^{2})

P_{pre} = \frac{E_{c} \cdot A}{L} δ_{c}

P

pre

= 164.2 lbf

Preload on rubber grommet (load @ installed)

^{δ} Rub = \frac{F_{Rub} L}{E_{c} A}

δ

Rub = 0.116 in

Deflection on rubber grommet due to breakaway torque

δ

Ratchet =

δ

Rub −

δ

c

δ

Rub = 0.116 in

Deflection (depth) for ratchet feature

E

c

= 100 . . . 1000

^{δ} Rub (E_{c}) = \frac{^{F} {Rub}^{L}}{E_{c} A}

FIG. 10

is a schematic view of drive sleeve teeth

128

engaged with inner hub teeth

152

. Drive sleeve

118

, inner hub

144

, and biasing member

170

(shown in

FIG. 2

) form a ratchet assembly that permits outer hub

108

to rotate relative to propeller shaft

102

when a sufficient torque is applied to propeller

106

. In one embodiment, drive sleeve

118

is fabricated from a resilient material and inner hub

144

is fabricated from brass. In an alternative embodiment, drive sleeve

118

is fabricated from brass and inner hub

144

is fabricated from a resilient material.

In the particular embodiment shown in

FIG. 10

, teeth

128

and

152

are tapered and are configured to provide for relative rotation of drive sleeve

118

to inner hub

144

at a preset torsional load. In one embodiment, the preset torsional load is 1000 ft-lbs. In the particular embodiment shown in

FIG. 10

, teeth

128

and

152

have a length of about 0.35 inches and include a pair of sidewalls angled with respect to longitudinal axis

138

of approximately 19.403 degrees. The configuration of teeth

128

and

152

is determined as follows.

TORQUE CALCULATIONS FOR TEETH

ENGAGEMENT

F

S

= spring force

F

T

= torque force = 1000 ft-lbs

φ

1

= tooth angle

ΣF

X

= 0

F

T

= Ncosφ

1

+ fsinφ

1

1)

ΣF

Y

= 0

F

S

= −fcosφ

1

+ Nsinφ

1

2)

f = μN μ = brass vs acetal

F

T

= N(cosφ

1

+ μsinφ

1

)

1a)

F

S

= N(−μcosφ

1

+ sinφ

1

)

2a)

Fs = F_{T} (\frac{- {µcosφ}_{1} + \sin φ_{1}}{\cos φ_{1} + µsin φ_{1}})

900 ft-lbs => 11,368 lbf therefore, F

S

= 22.411 lbf

approximate moment arm is about 0.95 in

\begin{matrix} (.95 in) (F_{T}) = 1000 ft lbs \\ F_{T} = (1000 ft lbs) \times \frac{12 in}{(0.95 in) (1 ft)} = 12, 632 lbs \end{matrix} &AutoRightMatch;

Determination of tooth angle given the spring force

Ft = 12632 lbf

μ = 0.35

φ = 15 deg, 16 deg, 45 deg

F3 = 24.917 lbf

Fs (φ) = \frac{Ft (\sin (φ) - µcos (φ))}{\cos (φ) + µsin (φ)}

Fs(19.403 deg) = 24.903 lbf

CALCULATION OF TEETH TORSIONAL

SHEAR

J = .62648456 in

4

from section PS B-14

SLEEVE SECT. E AREA = 1.0534426 in

2

(6 teeth)

TORQUE: 1000 ft-lbs

T = \frac{Jτ}{c}

c = 1.05 in

\begin{matrix} τ = \frac{Tc}{J} = \frac{1000 ft lbs (\frac{12 in}{ft}) (1.05 in)}{0.62648456 {in}^{4}} \\ = 70, 112.23 psi \end{matrix} &AutoRightMatch;

Propeller assembly

100

facilitates easy replacement of inner hub

144

. Specifically, in the event a user desires to replace inner hub

144

, the user simply removes propeller assembly

100

from propeller shaft

102

, and removes drive sleeve

118

and inner hub

144

from within outer hub

108

. A replacement inner hub

144

and/or drive sleeve

118

can then be utilized when reassembling propeller assembly

100

and mounting assembly

100

on propeller shaft

102

.

Further, different drive sleeves can be provided so that propeller

106

can be utilized on many different types of marine engines. For example, one particular marine engine may have splines on the propeller shaft of a first length, and another particular marine engine may have splines on a propeller shaft of a second length. Different drive sleeves having different length splines on their inner diameter surfaces can be provided. Although different drive sleeves are utilized, a same propeller can be used. That is, by providing interchangeable drive sleeves, one propeller can be used in conjunction with many different type engines.

Propeller assembly

100

can repeatedly handle impact torque load with no upper torque limit. Inner hub

144

, drive sleeve

118

and biasing mechanism

170

accommodate impact loads for a life of biasing mechanism

170

or friction wear surfaces of drive sleeve

118

and inner hub

144

.

It is contemplated that drive sleeve, inner hub, or both, could be sold in kit form. For example, different kits containing different drive sleeves specified for particular engine types could be provided. In one specific embodiment, a kit includes both a drive sleeve and a replaceable inner hub.

Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is intended by way of illustration and example only and is not to be taken by way of limitation. Accordingly, the spirit and scope of the invention are to be limited only by the terms of the appended claims.

Claims

1. An interchangeable drive sleeve for a propeller assembly to secure a propeller to a propeller shaft, said drive sleeve comprising a first portion, and a second portion comprising a plurality of teeth, said second portion having a larger outer diameter than an outer diameter of said first portion, thereby forming a ledge extending between said first portion and said second portion, said ledge configured to engage a biasing mechanism causing said teeth to engage a hub, the biasing mechanism configured to be engaged between the ledge and an outer hub.
2. An interchangeable drive sleeve in accordance with claim 1 further comprising a plurality of splines extending from an inner diameter surface of said drive sleeve.
3. An interchangeable drive sleeve in accordance with claim 2 wherein a longitudinal length of said splines extending from said drive sleeve inner diameter surface is configured to mate with a length of splines extending from an outer diameter surface of the propeller shaft.
4. A replaceable inner hub for a propeller assembly to secure a propeller to a propeller shaft, said inner hub comprising a body, a plurality of generally sinusoidal keys formed on an outer diameter surface of said inner hub extending from said body, and a plurality of teeth at one end of said body, wherein the inner hub is constructed to be positioned on the propeller shaft prior to positioning the propeller thereon.
5. A replaceable inner hub in accordance with claim 4 wherein said teeth are tapered.
6. A replaceable inner hub in accordance with claim 4 further comprising a plurality of intermediate sections connecting the keys, the teeth extending from an end of the inner hub.
7. A kit for securing a propeller to a propeller shaft of a marine engine, the kit comprising:a drive sleeve fabricated of brass comprising a first portion and a second portion, the second portion comprising a plurality of teeth, the second portion having a larger outer diameter than an outer diameter of the first portion; an inner hub comprising a plurality of teeth and an outer diameter, the outer diameter forming a plurality of integrally formed keys, an outer diameter of the keys being larger than the outer diameter of the second portion of the drive sleeve; and a biasing mechanism contacting the drive sleeve and biasing the drive sleeve such that the drive sleeve teeth engage the inner hub teeth.
8. A kit in accordance with claim 7 wherein said drive sleeve teeth extend from an end thereof.
9. A kit in accordance with claim 7 further comprising a plurality of splines extending from an inner diameter surface of said drive sleeve.
10. A kit in accordance with claim 7 wherein said splines are configured to extend a length similar to a length of splines extending from an outer diameter surface of the propeller shaft.
11. A kit in accordance with claim 7 wherein said drive sleeve teeth and said inner hub teeth are tapered.
12. A kit in accordance with claim 7 wherein said inner hub circumferentially engages an outer hub and axially engages said drive sleeve such that said inner hub is fixed relative to said outer hub and rotatable relative to the drive sleeve.
13. A kit in accordance with claim 12 wherein said inner hub keys are configured to mate with an inner diameter surface of a propeller outer hub.
14. A propeller assembly for being secured to a propeller shaft of a marine engine, said propeller assembly comprising:a drive sleeve comprising a first portion and a second portion, said second portion comprising a plurality of teeth and having a larger outer diameter than said first portion thereby forming a ledge between said first portion and said second portion; an inner hub comprising an outer diameter and a plurality of teeth at an end thereof, said outer diameter comprising a plurality of keys integrally formed therewith, an outer diameter of said keys being larger than the outer diameter of said second portion of said drive sleeve; a biasing mechanism contacting said drive sleeve at said ledge and biasing said drive sleeve such that said drive sleeve teeth engage said inner hub teeth; said biasing mechanism comprises a helical spring contacting an end of said outer hub and said drive sleeve ledge; and a propeller comprising an outer hub comprising a cylindrical shaped body and a plurality of blades extending from an outer diameter surface of said outer hub body, an inner diameter surface of said outer hub body comprising a plurality of keyways, said keyways shaped to mate with said inner hub keys to limit relative movement between said inner hub and said outer hub.
15. A propeller assembly in accordance with claim 14 wherein a plurality of splines are in an inner diameter surface of said drive sleeve.
16. A propeller assembly in accordance with claim 14 wherein said drive sleeve teeth extend from said drive sleeve second portion.
17. A propeller assembly in accordance with claim 14 wherein said inner hub is fabricated from one of brass and a resilient material.
18. A propeller assembly in accordance with claim 14 wherein said drive sleeve is fabricated from one of brass and a resilient material.
19. A propeller assembly in accordance with claim 14 wherein said drive sleeve comprises an outer diameter sized to enable said drive sleeve to rotate relative to said outer hub.
20. A propeller assembly in accordance with claim 14 wherein said drive sleeve is configured to deflect axially away from said inner hub upon the occurrence of a sufficient torque so that said drive sleeve teeth disengage said inner hub teeth and said drive sleeve is able to rotate relative to said inner hub.
21. A propeller assembly for being secured to a propeller shaft of a marine engine, the propeller assembly comprising:means for engaging said propeller shaft, the engaging means comprising a first portion and a second portion, the second portion comprising a plurality of teeth, the second portion having a larger outer diameter than an outer diameter of the first portion; an inner hub comprising an outer diameter and a plurality of teeth at an end thereof, the outer diameter of the inner hub comprising a plurality of keys integrally formed thereon, an outer diameter of the keys being larger than the outer diameter of said second portion of the engaging means; a propeller comprising an outer hub comprising a cylindrical shaped body and a plurality of blades extending from an outer diameter surface of the outer hub body, an inner diameter surface of the outer hub body comprising a plurality of keyways formed thereon, the keyways shaped to mate with the inner hub keys to limit relative movement between the inner hub and the outer hub; and means for biasing the engaging means from the outer hub of the propeller such that the engaging means teeth engage the inner hub teeth.
22. A propeller assembly in accordance with claim 21 wherein said engaging means comprises an inner diameter surface comprising a plurality of splines thereon.
23. A propeller assembly in accordance with claim 21 further comprising a ledge extending between said engaging means first portion and said engaging means second portion.
24. A propeller assembly in accordance with claim 21 wherein said biasing means comprises a helical spring contacting an end of said outer hub.
25. A propeller assembly in accordance with claim 21 wherein said inner hub is fabricated from one of brass and a resilient material.
26. A propeller assembly in accordance with claim 21 wherein said engaging means is fabricated from one of brass and a resilient material.
27. A propeller assembly in accordance with claim 21 wherein said engaging means comprises an outer diameter sized to enable said engaging means to rotate relative to said outer hub.
28. A propeller assembly in accordance with claim 21 wherein said engaging means is configured to deflect axially away from said inner hub upon the occurrence of a sufficient torque so that said engaging means teeth disengage said inner hub teeth and said engaging means is able to rotate relative to said inner hub.

US Referenced Citations (12)

Number	Name	Date	Kind
1515100	Foster	Nov 1924	A
1860750	Riggs	May 1932	A
2950797	Zieher	Aug 1960	A
3136400	Carr	Jun 1964	A
3880267	Auble et al.	Apr 1975	A
4566855	Costabile et al.	Jan 1986	A
4842483	Geary	Jun 1989	A
5201679	Velte, Jr. et al.	Apr 1993	A
5415575	Karls	May 1995	A
5908284	Lin	Jun 1999	A
5967751	Chen	Oct 1999	A
6086282	Dutt et al.	Jul 2000	A

Foreign Referenced Citations (1)

Number	Date	Country
4138917	Nov 1992	DE

Propeller assembly

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