Abstract: An apparatus, system and method for hydraulically adjusting and setting a fixed position of an axially displaceable shaft and rotary chipper disc combination, without requiring an attachment to or obstruction of an end face of either end of the axially displaceable shaft. A rotary chipper disc recoil mechanism is also provided for the purpose of detection of unwanted axial and radial forces placed upon the rotating shaft caused by unintentional chipping of metal, and for limiting consequential damage caused by the unintentional chipping of metal and other non-wood materials.

Abstract: A buoyancy engine, including an upper casing, a lower casing, and a manifold separating the upper and lower casings. The manifold has internal and external control means, that control amounts of liquid entering and leaving the manifold and casings through a primary route and an alternate route. There is a variably ballasted power piston within the upper casing, into and out of which liquid ballast can be pumped to change its buoyancy. There is a liquid discharge piston within the lower casing, that can be coupled to the variably ballasted power piston to form a primary pump. There is also a backup pump that can be used when the primary pump fails. A mechanical slide valve controls the entrance and exit of liquid from the manifold through the primary route.