Controlled Object - Machine, Basic Principles And Important Historical Figures

1. Definition of Machine

1. Core Definition

Machine: A device with a specific purpose that augments or replaces human/animal power to accomplish physical tasks.

Its core features include input (input), output (output) and energy/force/motion conversion and transmission device (transforming/transmitting device).

2. Scope of coverage

Machines are divided into two categories, covering simple to complex mechanical systems:

2. Energy Conversion & Classification of Machines 1. Energy conversion method

One of the core functions of the machine is energy conversion, which mainly includes:

2. Three Core Categories of Machines

category

English terms

Function description

Typical examples (Examples)

prime mover

Prime Movers

Obtain input energy from natural sources and convert it into mechanical energy (such as rotational axis motion)

Windmill, waterwheel, turbine, steam engine, internal-combustion engine

Generator/Energy Converter

Generators

Convert mechanical energy into other forms of usable energy (electrical energy, hydraulic energy, pneumatic energy)

Electric generator, hydraulic pump, air compressor

operating machine

Operators

It is neither a prime mover nor a generator, and directly completes specific physical tasks (including manually operated equipment)

Materials processing machinery, packaging machinery, sewing machine, calculating machine

Note: In practical applications, three types of machines are often used in combination (such as diesel electric locomotives: diesel engine → generator → electric motor → wheel drive).

3. Typical Components: Automobile Example (Typical Components: Automobile Example)

A car is a typical representative of a complex machine. Its core components and functions are as follows:

Part name

English terms

Function description

Slider crank mechanism

Slider-Crank Mechanism

Convert the linear motion of the piston (translatory/rectilinear motion) into the rotational motion of the crankshaft (rotary motion)

camshaft

Camshaft

Through the wedge-shaped action of cams, the opening and closing of valves are controlled to realize the entry of oil and gas and the discharge of exhaust gas.

flywheel

Flywheel

Use inertia to slow down fluctuations in crankshaft speed and make power output smoother

clutch

Clutch

Connect/disconnect the crankshaft and transmission to achieve unloaded start of the engine

transmission

Transmission

Change the ratio of input/output speed and torque to adapt to car start, stop and high-speed driving

drive shaft

Drive Shaft

Transmit transmission power to rear axle

universal joint

Universal Joint

Adapts to the relative movement of the body and the rear axle without affecting torque transmission

differential gear

Differential Gears

Allows the rear wheels on both sides to rotate at different speeds (such as when cornering) while maintaining power drive

Lubrication system

Lubrication

Reduce friction in engines, transmissions and other components and reduce energy loss

brake pads

Brake Shoes

Using friction to slow down or stop a vehicle is a "useful application" of friction

bevel gear

Bevel Gears

Realize the right-angle power connection between the drive shaft and the rear axle (the speed ratio is usually 1:3~1:4)

4. Core Principles of Machines 1. Constrained Motion

The most significant feature of the machine: the relative movement between components is limited by specific paths (guided by fixed paths), divided into two categories:

2. Mechanism & Kinematics of Machines 3. Work, Power & Efficiency

concept

English terms

Definitions and formulas

Unit

Work

The work done by the force in the direction of motion:

Linear motion: WORK = F×S (F = force, S = distance)

Rotational motion: WORK = T×θ (T = torque, θ = rotation angle)

Foot-pound, Joule

power

Power

Work done per unit time (work rate)

Horsepower (hp), Watt (Watt)

horsepower

Horse power (hp)

Imperial power unit: 1 hp = 33,000 foot-pounds per minute

Horsepower (hp)

efficiency

Efficiency

Ratio of output work to input work (always < 100% due to friction):

Efficiency = (Output Work / Input Work) × 100%

percentage(%)

4. Mechanical Advantage & Velocity Ratio 5. Key People

Core contributors to early machine invention and development:

1. Oliver Evans

Core contributions: high-pressure steam engines, automated production lines, early amphibious vehicles

2. Sir Marc Isambard Brunel

Core contributions: industrial machinery manufacturing, tunnel shield

technology

3. Elmer Ambrose Sperry

Core contribution: Gyro navigation and stabilization system

4. Johann Georg Bodmer

Core contributions: precision machine tools, textile machinery innovation

5. Sir Richard Arkwright

Core contributions: hydraulic spinning machine and factory production model