Abstract: A transmission for a marine propulsion device is provided with a movable member that responds to relative rotational movement between it and a driving shaft with an axial movement relative to the driving shaft and to a driven component. This axial movement is directed against one of two spring components which resist the axial movement. During the compression of either of the spring components, rotation of the driven component is non-synchronous with the driving component during a brief period of time. Also, the driven component is decoupled at least partially from torque transmitting relation with the driving component during the axial movement of the movable member relative to the driving and driven components.

Abstract: A two stage damping system is provided for a trim cylinder mount of a marine drive unit. The mounting bushings comprise inner and outer tubes with an elastomeric material disposed between the inner and outer tubes. The elastomeric material is structured to provide a soft rate of stiffness in response to relatively light loads, such as shifting loads, and a harder rate of stiffness in response to higher loads, such as during high thrust loads or wide open throttle operation of a marine vessel. The two rates of stiffness are provided by the appropriate placement of cavities either within the elastomeric material or between the elastomeric material and the inner or outer tubes. Alternatively, two different types of elastomeric material can be used to provide the two rates of stiffness.

Abstract: A shift linkage for a marine drive unit is provided with a groove that is aligned along a path which is nonperpendicular to an axis of rotation of the shift linkage. The groove, and its nonperpendicularity to the axis of rotation, allow a detent ball to smoothly roll or slide along the groove. This relationship helps to maintain the shift linkage in a desired vertical position as it passes from one gear selection position to another.

Abstract: In a marine drive (10), a nonrotational thrust sensing device (202 or 204) is placed between the stationary housing (26') and rotating propeller shaft (40' or 42') to measure the thrust output of a propeller (12 or 14) by measuring the equal and opposite force applied to the housing by the propeller shaft (40' or 42'). A thrust bearing (214 or 248) is situated between the rotating shaft and the nonrotating thrust sensing device. A thrust ring (246) and adapter (250) provide adoption of the thrust sensing device to a particular housing and shaft configuration. In a marine drive having counter rotating coaxial propeller shafts, first and second thrust sensors individually sense the thrust of inner and outer propeller shafts, respectively, to provide separate sensed thrust for each.

Abstract: A marine drive (10) has two counter-rotating surface operating propellers (12 and 14). A planing plate (230) extends rearwardly from the drive housing (20) above the propellers (12 and 14) and pushes down on the surface of the water during initial boat acceleration to in turn lower the bow and aid in getting the boat up on plane. Right and left inclined splash plates (240 and 242) along the sides of the housing (20) extend from the torpedo portion (188) rearwardly and upwardly at an incline and meet the planing plate (230).

Abstract: A marine drive (10) has two counter-rotating surface operating propellers (12 and 14). The lower horizontal torpedo portion (188) of the housing (20) has an upper zone (276) with outer surface profiles (11T-17T) along horizontal cross-sections defining wedges with sharp leading tips (11LT-17LT) forming a sharp leading edge (278) for slicing through the water, the sharp leading tips (11LT-17LT) defining the sharp leading edge (278) defining a first line extending downwardly and rearwardly at a first angle (280) relative to vertical. The torpedo portion (188) has a lower zone (270) with outer surface profiles (1B-10B) along horizontal cross-sections defining wedges with sharp leading tips (1LT-10LT) defining a second line (272) extending downwardly and rearwardly at a second angle (274) relative to vertical.

Abstract: A marine drive (10) has a water inlet (234) on the side of the skeg (194). One or more turning vanes (261, 289) receive incoming water flow and turn and direct same forwardly and upwardly within the skeg to a torpedo nose passage (198). A flow divider (284, 285) separates incoming water flow entering the water inlet opening into upper and lower water streams each initially flowing along a first path horizontally rearwardly and then along a second curved path and then merging along a third path upwardly and forwardly in an internal water passage (196) in the skeg. Water inlet plate structure maintains desired water intake flow volume.