THE THREE-POINT HITCHMECHANIZEM

M.M.Palitha Mahinda MunasingheFarm Mechanical Instructor

palithamahinda@yahoo.com

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The simplest and the only statically determinate way of joining two bodies

The implements can be Hooked on to the hitch Pulled and connected to the hitch

The way ploughs and other implements are attached to tractor

Hydraulic system, attaching points, the lifting arms, and stabilizers

Three-point hitches are composed of three movable arms The two outer arms – the lifting arms - are controlled by the hydraulic system, and

provide lifting, lowering, and even tilting to the arms The center arm – the top link - is movable, but is usually not powered by the tractor's hydraulic system

The three-point hitch is made up

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Lifting arms

Stabilizers

Top link

Three movable arms

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Top link Stabilizers

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Four different hitch sizes The higher category hitches have sturdier lift arms and

larger connector pins There is some flexibility in the tractor hp at which one

category hitch ends and the next begins

Categories

Category Tractor HPTop Link Pin

DiameterLift Arm Pin

Diameter

0 Up to 20 5/8 in 5/8 in

1 20 to 45-55 3/4 in 7/8 in

2 45-55 to 90-95 1 in 1 1/8 in

3 90-95 and up 1 1/4 in 1 7/16 in

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Is a spine driveshaft, usually on a tractor or truck Provide power to an attachment or separate machine Easily connected and disconnected The power take-off allows implements to draw energy from the tractor‘sengine

A power take-off (PTO)

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ISO 500-1 (General specifications, safety requirements, dimensions for master shield and clearance zone)ISO 500-2 (Narrow-track tractors, dimensions for master shield and clearance zone)ISO 500-3 (Main PTO dimensions and spine dimensions, location of PTO) The original type calls for operation at 540 revolutions per minute (RPM)A shaft that rotates at 540 rpm has 6 spines on it, and a diameter of 1⅜“

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Agricultural PTOs are standardized in dimensions and speed

Two newer types, supporting higher power applications, operate at 1000 RPM and differ in shaft size The larger shaft has 20 spines (1¾" diameter), while the smaller has 21 (1⅜" diameter) All three types rotate counterclockwise when viewed from the tractor A 10 spine type was used with some early equipment such as the 1948 Land Rover, a six spine adapter was usually supplied It is customary for agricultural machines manufacturers to provide the nominal PTO power specification and indication of the available instantaneous power at the shaft

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Three Point Hitch Mounting Method

The Ferguson three-point hitch system was the first agricultural use of a technology This technology made a huge difference in the power and control of agricultural

implements25/09/2008 mmpmm 11

Three Point Hitch Power Transmission

1. Hydraulic Pump 2. Cylinder Attach Bracket 3. Hydraulic Cylinder 4. Oil Reservoir 5. Steering Arm Link 6. Left Double Drop Arm 7. Right Single Drop Arm 8. Tie Rod 9. Hoses, Bolts, Clamps

Hydraulic System

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Install Hydraulic Pump (1) to engine Install Hydraulic Cylinder Mounting Plate (2) to transmission housing Install Oil Reservoir (4) to rear Valve Cover screw Install Left Double Drop arm (6). Adjust to original axis Install Right Single Drop arm (7). Adjust to original axis Mount Hydraulic Cylinder (3) to mounting plate and left double drop arm Install long steering link arm (5) Install Tie Rod (8) Install Hoses Fill Reservoir with SAE 20

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Installation Steps