Hotline: 0904.754.399
Ti?ng vi?tEnglish

1345
com_content.article
(0 votes, average 0 out of 5)
Các ??nh lu?t và công th?c tính tóan0 out of 50 based on 0 voters.



Pascal’s Law

Pressure exerted on a confined fluid is transmitted

undiminished in all directions, and acts with equal force

on all equal areas and at right angles to them.

 

Hydraulics

Simply, a means of power transmission.

 

Work

Force acting through distance.

WORK = FORCE x DISTANCE

Example: Work = lbs. x inches,

or Force (lbs.) x Distance (ins.)

 

Power

The rate of doing work.

Force

 

The Force (pounds) exerted by a piston can be

determined by multiplying the piston area (sq. inches)

by the pressure applied (psi).

Force = Pressure x Area

 

Volume

To determine volume (cubic inches) required to move a

piston a given distance, multiply the piston cross

sectional area (sq. inches) by the stroke required (inches).

Volume = Area x L

 

Compression of Hydraulic Oil

Hydraulic oil serves as an excellent lubricant, is practically

non-compressible. It will compress approximately 0.4 of

1% at 1000 psi and 1.1% at 3000 psi at 1200.

 

     

Weight of Hydraulic Oil

The weight of hydraulic oil may vary with a change in

viscosity; however, 55 to 58 lbs. per cubic foot covers the

viscosity range from 150 SSU to 900 SSU at 1000?F.

 

Pressure in a Column of Oil

The pressure at the bottom of a one-foot column of oil

will be approximately 0.4 psi. To find the approximate

pressure in psi at the bottom of any column of oil,

multiply the height in feet by 0.4.

 

Atmospheric pressure

Equivalent to 14.7 PSIA at sea level. ÄP means

pressure difference.

 

Gage readings

Gage readings do not include atmospheric pressure

unless marked PSIA.

 

Pressure drop

There must be a pressure drop (pressure difference)

across an orifice or restriction to cause flow through

it. Conversely, if there is no flow, there will be no

pressure drop.

 

Pumps and fluids

Fluid is pushed, not drawn, into a pump. If pumping

from an open reservoir, atmospheric pressure pushes the

fluid into the pump. Some pumps are used specifically

to create pressure. Any resulting flow is incidental. A

pump does not pump pressure; its purpose is to create

flow. A pump used to transmit power is usually positive

displacement type.

 

Pressure

Pressure is caused by resistance to flow. A pressure gage

indicates the pressure in a given unit, measured in PSI.

 


T́m ki?m s?n ph?m
Hàng có s?n trong kho!
Giá t?t khi mua s? l??ng l?n!