Patent Application
20090263258
This invention relates to hydraulic power units. More specifically, this invention relates to a hydraulic power unit that uses media therein to dampen noise of the unit.
Operators of equipment and vehicles that use various hydraulic power units such as hydraulic pumps, hydraulic motors, hydraulic rotary actuators, hydraulic valves and the like desire to reduce the noise levels that are produced by such units. Specifically, the government continues to require that noise levels in work settings produced by forklifts, backhoes, and the like that use hydraulic power units be minimized. Excess noise over long periods of time can cause workers to suffer from hearing loss, ringing ears, and the like.
Therefore, a principal object of the present invention is to provide a hydraulic unit that dampens the noise produced by a hydraulic assembly within the hydraulic power unit.
Another object of the present invention is to provide a means that dampens the overall noise produced by a hydraulic unit without contaminating fluids or damaging moving parts within the hydraulic power unit.
These and other objects, features or advantages of the present invention will become apparent from the specification and claims.
A hydraulic power unit comprising a housing having a hydraulic assembly disposed therein. Additionally disposed within the hydraulic power unit is at least a first cavity adjacent and surrounding the hydraulic assembly. Within the cavity is a quantity of media that acts to reduce or dampen noise produced by the hydraulic assembly.
In this embodiment a cavity 24 is disposed within the housing 12 adjacent and surrounding the hydraulic assembly 14. The cavity 24 is enclosed by the housing 12, a stove pipe tube 26 that surrounds the hydraulic assembly 14 and by swashplate 22 that is disposed within cavity 24. The stovepipe tube 26 has a plurality of openings 28 therein such that oil associated with the hydraulic assembly can communicate between the cavity 24 and the hydraulic assembly 14. Within the cavity 24 is a quantity of media 30.
In
The housing 12 additionally comprises a fill plug 32 that allows an operator to fill the cavity 24 with a quantity of media 30. Thus, once the media 30 is within cavity 24 the media acts to buffer or dampen the noise created by the hydraulic assembly 14 similar to how a bell that is partially filled with sand does not ring. Consequently, less noise is produced by the hydraulic power unit 10.
In this embodiment a second cavity 48 is provided that is considered a control circuitry cavity. The control circuitry cavity 48 has a cover member 50 and the second cavity 48 houses at least one interconnected circuit board 52. As with the first cavity 24 the second cavity 48 additionally houses a quantity of media 54 that may represent any of the media previously discussed. Thus, the media 54 in the second cavity 48 similarly acts to dampen noise produced by circuit board 52.
Disclosed are a plurality of embodiments of hydraulic units that use a first cavity 24 adjacent to a hydraulic assembly 14 to reduce the overall noise of the hydraulic power unit. Additionally, by using media 30 that is of size and shape that cannot be disposed through openings 28 of stove pipe tube 26, strainer 44 or by completely sealing the cavity 24 from the hydraulic assembly, damage to the hydraulic assembly 14 is minimized. Specifically, one skilled in the art would not think to use media and specifically granule type media within a hydraulic power unit as such a media could potentially cause major damage to the unit 10 and/or contaminate fluid within the unit. Thus, at the very least, all of the stated objectives have been met.
It will be appreciated by those skilled in the art that other various modifications could be made to the device without the parting from the spirit in scope of this invention. All such modifications and changes fall within the scope of the claims and are intended to be covered thereby.
