Brunswick Corporation

Roger E Koepsel

Ronald M Steiner

Michael A Karls

John O Scherer, Iii

Andrew C Gunderson

Robert B Weronke

Donald F Harry

Hubert S Gilgenbach

Terence C Reinke

Jeremy L Alby

John A Tuchscherer

Michael E Frazzell

Mitesh B Sheth

Michael P Mihelich

Carl G Schott

Daniel J Schlagenhaft

Edward M Thull

Daniel G Wilcox

William J Gius

John E Duprey

David M DeWitt

A method is for making a marine drive for propelling a marine vessel in water. The method includes providing a gearcase; installing a propeller shaft assembly that extends forwardly from the gearcase; coupling front and rear propellers to the propeller shaft assembly, forwardly of the gearcase, such that rotation of the propeller shaft assembly causes rotation of the front and rear propellers, respectively, which thereby propels the marine vessel in the water; and reducing deleterious effects of cavitation on the gearcase by the combination of forming the gearcase with a wide trailing end portion, in particular to maintain pressure alongside the gearcase, and configuring the front and rear propellers so that the front propeller absorbs more torque/thrust load than the rear propeller during said rotation.

Marine drives and methods of making marine drives so as to minimize deleterious effects of cavitation

A marine propeller has an outer hub having a central axis and a blade having a blade root attached to the outer hub and extending radially outward from the outer hub toward a blade tip. The blade has a leading edge and a trailing edge. The propeller has a diameter between about 15 inches and about 17 inches and a pitch between about 14 inches and about 24 inches. The blade has a progressive rake angle such that a first local rake angle at the blade root is less than a second local rake angle at the blade tip. A combination of the diameter, pitch, and progressive rake angle provides a marine vessel to which the marine propeller is coupled with minimum drag while the marine vessel is operating at less than a maximum vessel speed. A method of designing a propeller is also disclosed.

Marine propeller and method of design thereof

A marine propeller is provided with three blades, a skew angle of approximately 33 degrees, a rake angle of approximately 28.5 degrees, and a blade area ratio (BAR) of approximately 60 degrees. The rake is preferably progressive. Each of the blades is preferably tail loaded.

Marine propeller

A torque transfer mechanism for a marine propulsion system provides a connector mechanism, a first torque transfer mechanism, and a second torque transfer mechanism. A plurality of rods can provide the first torque transfer mechanism and a polymer component is shaped to provide the second torque transfer mechanism. All torque below a preselected magnitude is transferred through the first torque transfer mechanism and, for magnitudes of torque above the threshold, torque is transferred by both the first and second torque transfer mechanisms. The connector mechanism has an outer surface that is not used to transfer torque between it and an inner hub of a propulsor.

Dual rate torque transmitting device for a marine propeller

A controllable pitch propeller is provided with a blade that naturally tends to rotate in a direction toward maximum pitch as a result of the hydrodynamic forces on the blade. As a result, the blade will move toward a pitch position of increased pitch magnitude in the event that a control system failure occurs. If the blades of a propeller move naturally toward their maximum pitch position in the event of a hydraulic, mechanical, or electrical failure in the pitch control system, the propeller will be operable and will allow a marine vessel operator to navigate toward port even with a propeller pitch control system that has malfunctioned.

Controllable pitch propeller with a fail safe increased pitch movement

An improved twin propeller marine propulsion unit. A vertical drive shaft is journaled in the lower gearcase and drives a pair of bevel gears. A pair of concentric propeller shafts are mounted in the lower torpedo section of the gearcase and each shaft carries a propeller. A slidable clutch is movable between a neutral, a forward, and a reverse position and serves to operably connect the outer propeller shaft with one of the bevel gears when the clutch is moved to the forward drive position. A gear is mounted for sliding movement in unison with the clutch and acts to operably engage the inner propeller shaft with the second bevel gear when the clutch is in the forward drive position so that both propellers are driven in opposite directions to provide forward motion for the watercraft. The propulsion unit also includes a dual cooling water pick-up system in which seawater is drawn to the water pump both through a series of vertical inlet ports in the gearcase and through a plurality of inlet holes that are located in the forward end of the lower torpedo section. Exhaust gas from the engine is discharged through the rear end of the lower housing section through axial passages in the hub of the forward propeller and then across the outer surface of the rear propeller.

Marine propulsion unit with dual water inlet structure

Twin propeller marine propulsion unit

A marine propeller includes a hub rotatable about a longitudinal axis and having a plurality of blades extending radially outwardly therefrom and pivotable about respective radial pivot axes between a low pitch position and a high pitch position. A disc has a plurality of guide slots each receiving and retaining a respective lever arm extending rearwardly within the hub from a respective blade. A biasing spring coaxial with the longitudinal axis of rotation of the hub biases the disc to in turn bias the lever arms and blades to the low pitch position. The disc is a generally flat planar plate-like member extending radially outwardly from the longitudinal axis at the rear of the hub and includes a preload mechanism accessible at the rear of the hub for adjusting the bias. The disc restricts movement of the lever arms along the guide slots such that the lever arms can move only in unison, which prevents blade flutter. Pivoting of the blades is controlled by both a) movement of the lever arms along the guide slots, and b) arcuate movement of the guide slots as the disc rotates about the longitudinal axis, such that pivoting of each blade from its low pitch position to its high pitch position requires both a) movement of the respective lever arm along its respective guide slot, and b) rotation of the disc to arcuately move the guide slot.

Variable pitch marine propeller with shift biasing and synchronizing

A marine propeller (100) combines progressive pitch with both increasing pitch and increasing progressiveness of pitch along at least a portion of increasing radii from the axis of rotation to the outer blade tip. A five blade propeller is provided which accommodates thermal warpage of the outer blade tips, such that the same propeller includes two different types of blades, one blade having increasing pitch with increasing radii all the way to the outer blade tip, and the other type of blade having increasing pitch to a given radius and then decreasing pitch with increasing radii to the outer blade tip. The latter blade type is preferred and has a hump in the pressure surface at the noted given radius between portions of increasing and decreasing pitch with increasing radii.

Marine propeller with performance pitch, including five blade version

A marine propeller includes a hub rotatable about a longitudinal axis and having a plurality of blades extending radially outwardly therefrom and pivotable about respective radial pivot axes between a low pitch position and a high pitch position. Each blade has a hydrodynamic force characteristic which shifts the location of the resultant hydrodynamic force on the blade in a direction aiding up-pitching of the blade, and increasing the up-pitching pivot moment with decreasing angles of attack. A counteractive hydrodynamic force generating area is provided on the negative pressure backside surface of the blade and shifts the location of the resultant hydrodynamic force on the frontside surface forwardly with decreasing angle of attack. The blade is pivoted by increased water flow along the counteractive hydrodynamic force generating area with decreasing angles of attack, which increased water flow generates a backside hydrodynamic force on the blade at the counteractive hydrodynamic force generating area spaced from the pivot axis by a moment arm provided by the section of the blade between the pivot axis and the counteractive hydrodynamic force generating area, such that the backside hydrodynamic force acting on the moment arm pivots the blade to an increased pitch position. The counteractive hydrodynamic force generating area on the backside surface at the rearward trailing portion separates water flow along the backside surface at high angles of attack, and re-attaches water flow along the backside surface at low angles of attack to change the backside surface at the rearward trailing portion to a positive pressure area to generate the up-pitching moment.

Growing community of inventors

Oshkosh, WI, United States of America

Roger E Koepsel