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    Hps III

    Uploaded by

    prajakt_pie
    The document discusses various types of hydraulic cylinders and rotary actuators. It describes single acting cylinders that can only work in one direction versus double acting cylinders that can work in both directions. It also discusses different cylinder configurations like tandem cylinders, telescopic cylinders, and fast moving cylinders. Rotary actuators discussed include vane rotary actuators, parallel piston rotary actuators, limited angle rotary actuators, and rack-and-pinion piston rotary actuators. Buckling of piston rods and cushioning of cylinders are also summarized.

    Copyright:

    © All Rights Reserved
    Download as PPT, PDF, TXT or read online from Scribd

    Hps III

    Uploaded by

    prajakt_pie
    83 views29 pages
    The document discusses various types of hydraulic cylinders and rotary actuators. It describes single acting cylinders that can only work in one direction versus double acting cylinders that can work in both directions. It also discusses different cylinder configurations like tandem cylinders, telescopic cylinders, and fast moving cylinders. Rotary actuators discussed include vane rotary actuators, parallel piston rotary actuators, limited angle rotary actuators, and rack-and-pinion piston rotary actuators. Buckling of piston rods and cushioning of cylinders are also summarized.

    Original Description:

    Hydraulic 3

    Original Title

    hps_iii

    Copyright

    © © All Rights Reserved

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    The document discusses various types of hydraulic cylinders and rotary actuators. It describes single acting cylinders that can only work in one direction versus double acting cylinders that can work in both directions. It also discusses different cylinder configurations like tandem cylinders, telescopic cylinders, and fast moving cylinders. Rotary actuators discussed include vane rotary actuators, parallel piston rotary actuators, limited angle rotary actuators, and rack-and-pinion piston rotary actuators. Buckling of piston rods and cushioning of cylinders are also summarized.

    Copyright:

    © All Rights Reserved
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    83 views29 pages

    Hps III

    Uploaded by

    prajakt_pie
    The document discusses various types of hydraulic cylinders and rotary actuators. It describes single acting cylinders that can only work in one direction versus double acting cylinders that can work in both directions. It also discusses different cylinder configurations like tandem cylinders, telescopic cylinders, and fast moving cylinders. Rotary actuators discussed include vane rotary actuators, parallel piston rotary actuators, limited angle rotary actuators, and rack-and-pinion piston rotary actuators. Buckling of piston rods and cushioning of cylinders are also summarized.

    Copyright:

    © All Rights Reserved
    Download as PPT, PDF, TXT or read online from Scribd
    Download as ppt, pdf, or txt
    of 29

    Cylinder types:

    Hydraulic actuators: cylinders


    Double acting piston:

    Single acting:
    work can be done only in one direction

    Plunger

    Work is done in both


    directions
    Piston rod on both sides

    Piston

    Tandem

    Telescopic

    Fast moving

    Telescopic

    Fast moving

    Hydraulic cylinders
    Hydraulic cylinder
    Hidraulikus
    munkahengerek
    Rgztplcs kivitel 1.

    Rgztplcs hidraulika henger, a hengerfejen tallhat karims


    rgztssel

    Hydraulic cylinders
    Hydraulic cylinder

    Hidraulikus munkahengerek
    Hengeres kivitel 1.

    Hengeres ptsi mddal kszlt hidraulika henger

    Hydraulic cylinders
    Properties:
    The cylinders have to be good quality steel with close tolerances.
    There have to be good sealing both at the piston rod and at the
    cylinder.
    With time dirt may come in and damage the surfaces. This has to be
    possibly reduced.
    In this case, the leakage will increase all the time.

    Hydraulic cylinders
    Calculation of cylinders
    FCmax FLmax FF

    Fcmax FLmax FF F1
    maximum load

    Outward:
    Backward:

    friction forces

    inertial forces

    slow motion, can


    be often neglected

    FC 0 A1 p1 A2 p2

    FCB A2 p2 A1 p1

    Q
    v0
    A1

    Q
    vB
    A2

    A2

    A1

    p2
    p1
    Q

    vB
    v0

    Hydraulic cylinders
    Calculation of cylinders
    1.
    2.
    3.

    Stick-slip
    Transition
    Normal behaviour

    Ff

    Hydraulic cylinders should be possibly


    operated in the 3rd region for smooth
    operation.
    v

    If the cylinder is new, the leakage losses are


    negligibly small so that:

    v FL
    FL
    c

    p1Q1 p2Q2 p1 A1 p2 A2

    c = mech
    c
    outwards
    inward
    s
    p

    cmax 0,85 0,92


    at higher pressures

    Hydraulic cylinders
    Checking for buckling
    Maximum permissible force:
    2

    Fmax L

    1
    E I1
    n lk

    n: safety factor: 1-3,5


    lk: buckling length
    I1: moment of inertia of the piston rod
    E: elasticity modulus of the rod material

    d 4
    64

    Hydraulic cylinders
    Cushioning of cylinders:
    A hard impact of the piston at the end surfaces has to be inhibited
    kinetic energy has to be absorbed.
    This is done by increasing the hydraulic resistance at the end of
    the stroke.

    Rotary hydraulic actuators


    Swivel vane rotary actuator:
    Limited angle in both directions
    Maximum angle always smaller than 360

    Parallel
    piston rotary
    actuator
    Prhuzamd
    ugattys
    lenghajt
    s

    The same torque in both directions


    Limited angle rotary
    actuator

    Limited angle rotary


    actuator

    Piston rotary actuator:


    With rack and gear coupling
    Here maximum angle may be larger than 360
    ???

    Forgdugattys
    lenghajts
    menettel
    mkdtetett
    meghajtcsapp
    al

    Mindkt irnyban
    azonosan mkd
    hengerrel s
    fogaslces
    ??? meghajtssal
    mkdtetett
    toldugattys
    lenghajts

    Big pictures
    End of normal presentation
    Beginning of big pictures

    Hydraulic cylinders
    Cylinder types: plunger
    smaller force, better efficiency, axial support is necessary
    but cylinder does not have to be so good quality

    Without inner buffer

    With inner buffer (pilot piston)

    Hydraulic cylinders
    Cylinder types: piston, single acting, pressing-cylinder

    Spring
    inside

    outside

    Hydraulic cylinders
    Cylinder types: piston, single acting, puller

    Spring
    inside

    outside

    Hydraulic cylinders
    Cylinder types: piston, double acting

    Velocity is different

    Hydraulic cylinders
    Cylinder types: piston, double acting
    Piston rod on both side

    Velocity is the same in both directions

    Hydraulic cylinders
    Cylinder types: piston, double acting
    Piston rod on both side

    Velocity is different in the two directions depending


    on cross section ratio of the rods

    Hydraulic cylinders
    Cylinder types: double acting piston, tandem

    Hydraulic cylinders
    Cylinder types: single acting, fast moving

    Hydraulic cylinders
    Cylinder types: double acting, fast moving

    Hydraulic cylinders
    Cylinder types: telescopic, single acting

    Large working paths


    or limited space

    Hydraulic cylinders
    Cylinder types: telescopic, double acting

    Large working paths


    or limited space

    Hydraulic cylinders
    Checking for buckling:
    Eulers
    cases

    1. Case

    2. Case

    3. Case

    4. Case

    One end free


    One end fixed
    Or trunnion at end

    Two ends pivoted


    and guided

    One end guided and


    pivoted, other end
    fixed

    Two ends fixed and


    guided

    Picture

    Free buckling
    length
    mounting style

    Manner of
    end fixing

    Note

    mounting style

    mounting style

    mounting style

    Hydraulic cylinders
    Cushioning of cylinders:
    1.

    Piston

    2.

    Cushion nose

    3.

    Cylinder cap

    4.

    Stroke volume

    5.

    Cushion orifice

    6.

    Throttle

    7.

    Cushion adjustment screw

    8.

    Mother

    9.

    Non-return valve

    10. Gas valve

    Rotary hydraulic actuators


    Parallel piston rotary
    actuator

    Rotary hydraulic actuators


    ???

    Rotary hydraulic actuators


    Rack-and-pinion piston-type rotary actuator:

    Rotary hydraulic actuators


    Limited angle rotary actuator:

    Rotary hydraulic actuators


    Limited angle rotary actuator:

    Rotary hydraulic actuators


    Helix actuator:

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