CA1079582A - Boat propeller hub - Google Patents
Boat propeller hubInfo
- Publication number
- CA1079582A CA1079582A CA305,020A CA305020A CA1079582A CA 1079582 A CA1079582 A CA 1079582A CA 305020 A CA305020 A CA 305020A CA 1079582 A CA1079582 A CA 1079582A
- Authority
- CA
- Canada
- Prior art keywords
- bushing
- hub according
- hub
- propeller
- vulcanized
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H1/00—Propulsive elements directly acting on water
- B63H1/02—Propulsive elements directly acting on water of rotary type
- B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
- B63H1/14—Propellers
- B63H1/20—Hubs; Blade connections
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Springs (AREA)
- Support Of The Bearing (AREA)
- Motor Power Transmission Devices (AREA)
- Shafts, Cranks, Connecting Bars, And Related Bearings (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A boat propeller hub comprises an inner sleeve for rigid attachment to a propeller shaft, an outer sleeve disposed concentrically with the inner sleeve and arranged to carry propeller blades, and a bushing of elastic material disposed between the inner and the outer sleeves, said bushing having a greater wall thickness at its end portion that at its middle portion.
A boat propeller hub comprises an inner sleeve for rigid attachment to a propeller shaft, an outer sleeve disposed concentrically with the inner sleeve and arranged to carry propeller blades, and a bushing of elastic material disposed between the inner and the outer sleeves, said bushing having a greater wall thickness at its end portion that at its middle portion.
Description
The presen~ invention rela~es ~o a boa~ propeller hub 9 comprisin~ an inn~r sleeve in~ended ~o be rigidly joined to a propeller shaft 9 an ou~er sleeve concentric with the inner sleeve and intended to carry propeller blades, and a busning of S elastic material disposed be~een the inner and outer sleeves.
Propeller hubs of this type ars used primarlly in recreational boats with power~ul mo~ors, to dampen shocks to the drive uni~, for example when the boat bounces in the water while moving at high speed or when shlf~ing rapidly between forward and reverse. What is desired is low stiffness and high strength in order to achieve ef~ective dampening in combination wi~h long life.
For a long time now known propeller hubs of this type have been of right cir~ular cylindrical shape with planar ends, i.e. the inner and outer sIeeves as ~he bushings a~e made with right circular cylindrical shape with constant wall thickness.
As the power of mo~ors has increased and the hub has been subjected to heavier loads, hubs constructed in this way have proven to have an unacceptably short li~e, because the 1exible rubber bushing is soon torn apart. Tests have shown that the rupture begins a~ ~he ends, close to ~he inner sleeve, and continues axially inwards towards the middle o~ ~he bushing.
The purpose of the present inven~ion is to achieve a propeller hub which, for a given hub snace in a propeller, will t~ke gr~ater stresses than said hubs used up to now.
This is achieved according to the invention by ~he bushing havin~ a ~reater wall tllickness at its end portions than in its middle portionO
~ -'.
Ilith this new end construc~ion it has been shown ~hat the shear stress can be reduced locally more than 20~, which means that the strength and life of the hub can be a~preciably improved wi~hout having to change the outer dimensions of the hub. This, in turn, means that existing pro~ellers and installations need not be modiied in order to be able to be used together with the hub according to the invention.
The invention will now be described in more detail wi~h refe~ence to the accompanying drawing showins an example. The figure shows a longitudinal section through a propeller hub aGcording to the invention shown in its ac~ual size.
The hub shown consists generally of an inner sleeve 1 of metal, a bushing 2 of elastic material, pr~ferably rubber, and an outer sleeve 3 of metal. The inner sleeve 1 i5 intended ~o be non-rotatably joined by means of splines 4 to a propeller shaft, while ~he outer sleeve 3 is intended to be inserted in a .
hub opening in a propeller and be cemented, for example, ~o the ..
side o the opening, The inner sleeve 1 has a main portion 5 with a constant ex~ernal diameter and, on both sides thereo~, portions 6 with successively decreasing external diameters. Furthermore, the inner sleeve 1 has at one end a flange 7 which extends radially to the o~ter sleeve 3 for radial control of the same, In a corresponding manner the bushing 2 has a major por~ion 8 with constan~ inner diameter and, on bokh sides thereofJ end portions 9 with successively decreasin~ inner diameters, so that the portions 9 of the bushing have a greater wall thickness than the other portion 8O The bushing 2 is ~:
, ~2-. ..... : - . . .-.. . ;. . ,- . . . . ~ . .: ..
.. ~ . . . . .
vulcanized to the surfaces o~ the inner 1 and ou~er 3 sleeves except at the surface o the radial flange between ~he arrows a and b. At the right-hand end of the bushing in the figure, a prote~tive casing 10 of stainless steel .is cemented on.
The embodiment shown and described achieves a reduction of the stress at the sensitive end surfaces of the hub as compared with known hubs with right circular cylindrical rubber bushings and straight end suraces. The greatest shear stress occurring in the inner sleeve is, where the bushing is thickest, more than 203 lowsr than wllere the bushin~ is thinnest in the embodiment shown.
The invention has been described in the preceding with reference to an example in which the inner diameter of the bushing has been varied to achieve a greater wall thickness at the ends of the bushing~ This is preferabl~ since a constant external diameter permits the use of existing propellers without modification.
However, it is also possible within the scope of the invention, if it should be desirable, to keep the inner diame~er constant instead and vary the outer diameter or, alterna~iv~ly, to vary both the outer and inner diameters to obtain a grea~er wall thickness ~owards the ends.
Propeller hubs of this type ars used primarlly in recreational boats with power~ul mo~ors, to dampen shocks to the drive uni~, for example when the boat bounces in the water while moving at high speed or when shlf~ing rapidly between forward and reverse. What is desired is low stiffness and high strength in order to achieve ef~ective dampening in combination wi~h long life.
For a long time now known propeller hubs of this type have been of right cir~ular cylindrical shape with planar ends, i.e. the inner and outer sIeeves as ~he bushings a~e made with right circular cylindrical shape with constant wall thickness.
As the power of mo~ors has increased and the hub has been subjected to heavier loads, hubs constructed in this way have proven to have an unacceptably short li~e, because the 1exible rubber bushing is soon torn apart. Tests have shown that the rupture begins a~ ~he ends, close to ~he inner sleeve, and continues axially inwards towards the middle o~ ~he bushing.
The purpose of the present inven~ion is to achieve a propeller hub which, for a given hub snace in a propeller, will t~ke gr~ater stresses than said hubs used up to now.
This is achieved according to the invention by ~he bushing havin~ a ~reater wall tllickness at its end portions than in its middle portionO
~ -'.
Ilith this new end construc~ion it has been shown ~hat the shear stress can be reduced locally more than 20~, which means that the strength and life of the hub can be a~preciably improved wi~hout having to change the outer dimensions of the hub. This, in turn, means that existing pro~ellers and installations need not be modiied in order to be able to be used together with the hub according to the invention.
The invention will now be described in more detail wi~h refe~ence to the accompanying drawing showins an example. The figure shows a longitudinal section through a propeller hub aGcording to the invention shown in its ac~ual size.
The hub shown consists generally of an inner sleeve 1 of metal, a bushing 2 of elastic material, pr~ferably rubber, and an outer sleeve 3 of metal. The inner sleeve 1 i5 intended ~o be non-rotatably joined by means of splines 4 to a propeller shaft, while ~he outer sleeve 3 is intended to be inserted in a .
hub opening in a propeller and be cemented, for example, ~o the ..
side o the opening, The inner sleeve 1 has a main portion 5 with a constant ex~ernal diameter and, on both sides thereo~, portions 6 with successively decreasing external diameters. Furthermore, the inner sleeve 1 has at one end a flange 7 which extends radially to the o~ter sleeve 3 for radial control of the same, In a corresponding manner the bushing 2 has a major por~ion 8 with constan~ inner diameter and, on bokh sides thereofJ end portions 9 with successively decreasin~ inner diameters, so that the portions 9 of the bushing have a greater wall thickness than the other portion 8O The bushing 2 is ~:
, ~2-. ..... : - . . .-.. . ;. . ,- . . . . ~ . .: ..
.. ~ . . . . .
vulcanized to the surfaces o~ the inner 1 and ou~er 3 sleeves except at the surface o the radial flange between ~he arrows a and b. At the right-hand end of the bushing in the figure, a prote~tive casing 10 of stainless steel .is cemented on.
The embodiment shown and described achieves a reduction of the stress at the sensitive end surfaces of the hub as compared with known hubs with right circular cylindrical rubber bushings and straight end suraces. The greatest shear stress occurring in the inner sleeve is, where the bushing is thickest, more than 203 lowsr than wllere the bushin~ is thinnest in the embodiment shown.
The invention has been described in the preceding with reference to an example in which the inner diameter of the bushing has been varied to achieve a greater wall thickness at the ends of the bushing~ This is preferabl~ since a constant external diameter permits the use of existing propellers without modification.
However, it is also possible within the scope of the invention, if it should be desirable, to keep the inner diame~er constant instead and vary the outer diameter or, alterna~iv~ly, to vary both the outer and inner diameters to obtain a grea~er wall thickness ~owards the ends.
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Boat propeller hub, comprising an inner sleeve for rigid attachment to a propeller shaft, an outer sleeve disposed concentrically with the inner sleeve and arranged to carry propeller blades, and a bushing of elastic material disposed between the inner and the outer sleeves, characterized in that the bushing has a greater wall thickness at its end portions than at its middle portion.
2. Hub according to claim 1, characterized in that the bushing has a portion with constant wall thickness which passes towards the ends into portions with successively increasing wall thickness.
3. Hub according to claim 2, characterized in that the bushing has a constant outer diameter and an inner diameter which successively decreases towards the ends.
4. Hub according to claim 1, characterized in that the bushing consists of rubber which is vulcanized to the inner and outer sleeves.
5. Hub according to claim 2, characterized in that the bushing consists of rubber which is vulcanized to the inner and outer sleeves.
6. Hub according to claim 3, characterized in that the bushing consists of rubber which is vulcanized to the inner and outer sleeves.
7. Hub according to claim 4, 5 or 6, characterized in that the inner sleeve is made at one end with an outwardly-directed flange abutting one end of the bushing without the bushing being vulcanized to the flange.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE7706728A SE410422B (en) | 1977-06-09 | 1977-06-09 | BAT PROPELLER Hub |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1079582A true CA1079582A (en) | 1980-06-17 |
Family
ID=20331560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA305,020A Expired CA1079582A (en) | 1977-06-09 | 1978-06-08 | Boat propeller hub |
Country Status (9)
| Country | Link |
|---|---|
| JP (1) | JPS5440494A (en) |
| AU (1) | AU523067B2 (en) |
| BR (1) | BR7803668A (en) |
| CA (1) | CA1079582A (en) |
| DE (1) | DE2825256A1 (en) |
| FR (1) | FR2393722A1 (en) |
| GB (1) | GB1563180A (en) |
| IT (1) | IT1105114B (en) |
| SE (1) | SE410422B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5970295A (en) * | 1982-10-13 | 1984-04-20 | Sanshin Ind Co Ltd | Buffering device for propeller of outboard engine and the like |
| JPS60221199A (en) * | 1984-04-17 | 1985-11-05 | Sumitomo Heavy Ind Ltd | Method and tool for correcting dislocation in welding joint part |
| JPS6322300U (en) * | 1986-07-29 | 1988-02-13 |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2974984A (en) * | 1959-05-18 | 1961-03-14 | Westinghouse Electric Corp | Coupling apparatus |
| US3307634A (en) * | 1966-01-17 | 1967-03-07 | Otto L Bihlmire | Hub construction for boat propellers |
| US3563670A (en) * | 1969-01-31 | 1971-02-16 | Brunswick Corp | Marine propeller and its mounting |
| FR2057347A5 (en) * | 1969-08-13 | 1971-05-21 | Metivier Christian | Shock absorbing joints between moving parts |
| JPS4977390A (en) * | 1972-11-29 | 1974-07-25 |
-
1977
- 1977-06-09 SE SE7706728A patent/SE410422B/en not_active IP Right Cessation
-
1978
- 1978-05-31 GB GB24766/78A patent/GB1563180A/en not_active Expired
- 1978-06-07 AU AU36898/78A patent/AU523067B2/en not_active Expired
- 1978-06-07 IT IT49758/78A patent/IT1105114B/en active
- 1978-06-07 FR FR787817082A patent/FR2393722A1/en active Granted
- 1978-06-08 BR BR7803668A patent/BR7803668A/en unknown
- 1978-06-08 CA CA305,020A patent/CA1079582A/en not_active Expired
- 1978-06-08 DE DE19782825256 patent/DE2825256A1/en active Granted
- 1978-06-09 JP JP6977678A patent/JPS5440494A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| AU523067B2 (en) | 1982-07-08 |
| JPS5440494A (en) | 1979-03-29 |
| AU3689878A (en) | 1979-12-13 |
| GB1563180A (en) | 1980-03-19 |
| FR2393722A1 (en) | 1979-01-05 |
| BR7803668A (en) | 1979-01-09 |
| SE7706728L (en) | 1978-12-10 |
| IT1105114B (en) | 1985-10-28 |
| FR2393722B1 (en) | 1983-07-01 |
| SE410422B (en) | 1979-10-15 |
| DE2825256A1 (en) | 1978-12-21 |
| JPS6220079B2 (en) | 1987-05-02 |
| DE2825256C2 (en) | 1987-09-24 |
| IT7849758A0 (en) | 1978-06-07 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |