Stern drives having breakaway lower gearcase

Patent metadata

Field	Value
Publication number	US-11975812-B2
Application number	US-202117518935-A
Country	US
Kind code	B2
Filing date	Nov 4, 2021
Priority date	Jun 23, 2020
Publication date	May 7, 2024
Grant date	May 7, 2024

Abstract

A stern drive is for propelling a marine vessel in water. The stern drive has an upper drive unit with a lower mounting surface; a lower gearcase coupled to the lower mounting surface and a trailing end surface that is angled relative to the lower mounting surface; and a propeller shaft extending forwardly from the lower gearcase and being configured to rotate a propeller for pulling the marine vessel in the water. The upper drive unit and the lower gearcase are configured such that when a forward side of the lower gearcase impacts an underwater obstruction, the lower gearcase is caused to pivot relative to the upper drive unit until the trailing end surface impacts the lower mounting surface, which thereby causes the lower gearcase to completely uncouple from the upper drive unit.

First claim

What is claimed is:

1. A drive for propelling a marine vessel in water, the drive comprising:
an upper drive unit;
a lower gearcase coupled to upper drive unit and having a trailing end surface;
wherein the upper drive unit and the lower gearcase are configured such that when a forward side of the lower gearcase impacts an underwater obstruction, the lower gearcase is caused to rearwardly pivot relative to the upper drive unit until the trailing end surface impacts the upper drive unit, which thereby causes the lower gearcase to completely uncouple from the upper drive unit; and
a trim actuator configured to trim the upper drive unit relative to the marine vessel, wherein the upper drive unit, the lower gearcase, and the trim actuator are configured such that when the forward side of the lower gearcase impacts the underwater obstruction, the upper drive unit is caused to trim up relative to the marine vessel and the lower gearcase is caused to rearwardly pivot relative to the upper drive unit, until the trailing end surface impacts upper drive unit, which thereby causes the lower gearcase to completely uncouple from the upper drive unit.

2. The drive according to claim 1 , wherein the trim actuator is a hydraulic actuator comprising a cylinder and a piston rod extending from the cylinder, wherein the piston rod is extended outwardly towards an outermost position relative to the cylinder to thereby trim the drive up relative to the marine vessel and wherein the piston rod is retracted inwardly towards an innermost position relative to the cylinder to thereby trim the drive down relative to the marine vessel.

3. The drive according to claim 2 , wherein when the forward side of the lower gearcase impacts the underwater obstruction, the upper drive unit is caused to trim up relative to the marine vessel, which in turn causes the piston rod to extend outwardly to the outermost position, and wherein thereafter the trailing end surface impacts the upper drive unit, which thereby causes the lower gearcase to completely uncouple from the upper drive unit.

4. The drive according to claim 3 , wherein the upper drive unit extends rearwardly of the lower gearcase so that when the trailing end surface impacts the upper drive unit, the lower gearcase is forced rearwardly and downwardly relative to the marine vessel and more specifically is prevented from moving upwardly out of the water.

5. The drive according to claim 1 , wherein the upper drive unit comprises a driveshaft housing and an adapter plate on the driveshaft housing, wherein the adapter plate is sandwiched between the upper drive unit and the lower gearcase.

6. The drive according to claim 5 , wherein the driveshaft housing comprises a lower mounting flange, and wherein the adapter plate comprises a lower mounting surface and further comprises an upper mounting surface that faces the lower mounting flange.

7. The drive according to claim 6 , wherein the lower gearcase comprises an upper mounting flange that is fastened to the lower mounting surface.

8. The drive according to claim 7 , wherein the lower mounting surface comprises a recess into which the upper mounting flange is nested.

9. The drive according to claim 7 , wherein the lower gearcase is fastened to the adapter plate by a forward mounting joint comprising port and starboard fasteners that extend through the upper mounting flange and into port and starboard threaded holes in the adapter plate, respectively.

10. The drive according to claim 9 , wherein the lower gearcase is also fastened to the adapter plate by a rearward mounting joint comprising port and starboard threaded studs extending from the lower mounting surface and through port and starboard through-bores in the upper mounting flange.

11. The drive according to claim 10 , further comprising fastener nuts that are threaded onto the port and starboard threaded studs to fasten the lower gearcase to the adapter plate.

12. The drive according to claim 10 , wherein the adapter plate defines first passageway through which a driveshaft of the drive extends, and wherein the port and starboard through-bores in the adapter plate are diametrically opposed to each other relative to the passageway, on the port and starboard sides of the drive, respectively.

13. The drive according to claim 12 , wherein the adapter plate defines a second passageway through which exhaust from the drive is conveyed from the upper drive unit to the lower gearcase, and wherein the port and starboard threaded studs are located rearwardly of the second passageway and on the port and starboard sides of the drive, respectively.

14. The drive according to claim 10 , wherein the port and starboard threaded studs define a pivot axis about which the lower gearcase is caused to rearwardly pivot relative to the upper drive unit when the forward side of the lower gearcase impacts the underwater obstruction.

15. The drive according to claim 5 , wherein the adapter plate comprises a lower mounting surface and wherein the lower mounting surface extends above and rearwardly of the trailing end surface of the lower gearcase and as such is configured to cause the lower gearcase to move downwardly upon separation from the upper drive unit and more particularly prevents the lower gearcase from traveling upwardly out of the water.

16. A drive for propelling a marine vessel in water, the drive extending from top to bottom in an axial direction, from forward side to trailing side in a longitudinal direction that is transverse to the axial direction, and from port side to starboard side in a lateral direction that is transverse to the axial direction and transverse to the longitudinal direction, the drive comprising:
an upper drive unit; and
a lower gearcase coupled to the upper drive unit and having a trailing end surface;
wherein the lower gearcase is mounted to the upper drive unit by a forward mounting joint and a trailing mounting joint located rearwardly of the forward mounting joint in the longitudinal direction; and
wherein the upper drive unit and the lower gearcase are configured such that when the forward side of the lower gearcase impacts an underwater obstruction, the forward mounting joint is configured to fail, thus permitting the lower gearcase to rearwardly pivot relative to the upper drive unit about a pivot axis defined by the trailing mounting joint, until the trailing end surface impacts the upper drive unit, which thereby breaks the trailing mounting joint and allows the lower gearcase to completely uncouple from the upper drive unit.

17. The drive according to claim 16 , further comprising a trim actuator configured to trim the drive relative to the marine vessel, wherein the upper drive unit, the lower gearcase, and the trim actuator are configured such that when the forward side of the lower gearcase impacts the underwater obstruction, the upper drive unit is caused to trim up relative to the marine vessel about a trim axis and the lower gearcase is caused to rearwardly pivot relative to the upper drive unit about the trailing mounting joint, until the trailing end surface impacts the upper drive unit, which thereby breaks the trailing mounting joint and so causes the lower gearcase to completely uncouple from the upper drive unit.

18. The drive according to claim 17 , further comprising a gimbal ring and gimbal housing for coupling the upper drive unit to the marine vessel, wherein the trim actuator is a hydraulic actuator comprising a cylinder and a piston rod extending from the cylinder, wherein the piston rod is extended outwardl

Assignees

• Brunswick Corp

Inventors

• Waldvogel David J
• Poirier Randall J
• Scherer Iii John O
• Collins Stephen R
• Jaszewski Wayne M
• Moore Kevin M

Classifications

• B63H21/30 Primary

  Mounting of propulsion plant or unit, e.g. for anti-vibration purposes (hull reinforcements therefor B63B3/70) · CPC title

• B63B43/18

  preventing collision {or grounding}; reducing collision damage {(reducing pollution by collision B63B25/082)} · CPC title

• B63H5/125

  movably mounted with respect to hull, e.g. adjustable in direction {, e.g. podded azimuthing thrusters}({outboard units or Z-drives B63H20/00; } movably mounted for steering purposes only, {rudders carrying propellers} B63H25/42) · CPC title

• B63H2005/1256

  with mechanical power transmission to propellers · CPC title

• B63H2021/307

  Arrangements, or mountings of propulsion power plant elements in modular propulsion power units, e.g. using containers · CPC title