Machinery Flashcards
Stage one of 2stroke engine
With the piston rising, the suction created behind it causes air/fuel to be drawn into the crankcase through a port.
Stage2 of 2stroke engine
With the piston at the top of its stroke the spark plug will ignite or the diesel fuel will be injected, combustion will then take place.
Stage 3 of 2stroke engine
As the piston is forced down by combustion the pressure beneath the piston builds within the crankcase and the fuel mix is sent up through the transfer port in the cylinder just above the piston. At the same time, the action of the fuel mix going into the combustion chamber forces the spent exhaust gases out of the cylinder through the exhaust port.
Stage 4 of the 2stroke engine
The piston has got to the bottom of its stroke; the inducted fuel mix from the crankcase has been forced up the transfer port to the combustion chamber where it has forced out the exhaust gasses from the previous firing stroke of the engine.
Gear drives
Power transmitted through direct contact between interlocking teeth- positive engagement.
Belt drives
Power transmitted through friction between a belt and pulleys.
Contact and slip in Gear drives
No slip due to meshing teeth, ensures precise transmission.
Contact and slip in belt drives
Some slip may occur, especially underload, leading to less precision.
Noise and vibration gear drives
Noisier due to metal-on-metal contact and higher vibration
Noise and vibration belt drives
Quieter and smoother, absorbs vibration.
Speed and load capacity gear drives
Suitable for high-load and high-torque applications
Speed and load capacity belt drives
More suited for lighter loads and moderate speeds
Durability and maintenance gear drives
Long-lasting but require regular lubrication and maintenance
Durability and maintenance belt drives
Shorter lifespan, belts need periodic replacement but require less maintenance
Alignment and space gear drives
Precise alignment required, less flexible in shaft distance
Alignment and space belt drives
Tolerates slight misalignment, can work over longer distances
Cost gear drives
More expensive
Cost belt drives
Cheaper
Efficiency gear drives
High efficiency 95-98%
Efficiency belt drives
Slightly less efficient 90-95% due friction and slip
Manual transmission
The driver manually shifts gears using a clutch and gear stick, offering more control and often higher fuel efficiency.
Automatic transmission
Gears shift automatically based on speed and load, providing ease of use and less driver effort but typically with lower fuel efficiency.
Semi-automatic transmission
A hybrid of manual and automatic, this system allows for gear selection without a clutch pedal, offering more control than an automatic but less complexity than manual.
Types of power
Electric, battery, spark ignition, compression ignition, PTO, hydraulic
Electric power
These machines are powered by plugging into an electric outlet or charging a battery. They are often quieter environmentally friendly and have lower maintenance requirements but my lack power
Spark ignition
Common in smaller machines mowers, chainsaws, strimmers, ATVs. They’re powerful enough for moderate jobs and are easy to refuel but can produce more noise ans emissions compared to electric or battery powered options.
Compression ignition
Diesel engines are powerful and fuel efficient, making them suitable for big jobs. They use high compression to ignite the file rather than spark, which increases their power output and emissions. Large tractors, propelled harvesters and diesel-powered forklifts.
PTO
The PTO is a mechanism on tractors that provides power to attached equipment by transferring engine power directly to the implement through a rotating shaft. It allows for versatile use of various attachments without each needing it’s own engine. Rotary tillers, mowers, or augers that attach to tractors PTO shaft.
Hydraulic power
Hydraulic power uses fluid pressure to move parts and generate force. It’s very powerful and efficient for lifting or cutting tasks, as seen in hydraulic loaders and backhoes. It’s often used for attachments requiring high force without a sperate engine. Log splitters, backhoes, and some tractor attachments.
Trailed type implement
It is one that is pulled and guided from single hitch point but it’s weight is not supported by the tractor.
Semi-mounted type implement
This type of implement is one attached to the tractor only to lower link of the hydraulic system. It is controlled directly by tractor steering unit but the weight is partly supported by the tractor.
Mounted type implement
Is one which is attached to the three point linkage of the hydraulic system, which can be controlled directly by the tractor steering unit. The implement is carried fully by the tractor. It can be raised, lowered and hold in any position.
Stage one of the 4 stroke
Induction as the piston travels down the cylinder, it draws the air or fuel/air mixture into the cylinder through the inlet manifold and the inlet valve.
Stage 2 of the 4 stroke
Compression as the piston travels up to the top of the cylinder, it squeezes or compresses the air or fuel/air mixture from the carburettor in the top of the cylinder, making the fuel/air mix ready for igniting
Stage 3 of the 4 stroke
Power when the spark plug ignites the compressed fuel/air mixture in a diesel system the combustion happens when fuel is injected under high pressure so it is in an atomised form that combusts when injected in hot, pressurised air. In both systems the piston has squeezed the air/fuel to a high temperature and is in a volatile state. This forces the piston downward turning the crankshaft and giving the engine it’s power to operate.
Stage 4 of the 4 stroke
Exhaust as the piston returns back to the top of the cylinder head after combustion has taken place, the rising piston pushes the burnt ‘exhaust’ gases out of the cylinder and through the exhaust system and once it has reached the top of this stroke it is ready to start it’s downward journey again with the induction stroke and the cycle starts all over again.
