Generalized Process for Standard Specifications

Primary and Secondary Functions

The first step in specification of a COT component is the identification of the type of component. This will depend on the primary function of the component. However, there are many components that can implement similar high-level functions. The decision often comes down to secondary functionality. For example, the primary function of “transmit power” can be accomplished with many different types of components such as belts, various types of gearing etc. However, if secondary functionality like changing the direction of the power is also needed, then components like bevel gears make more sense than belts and pulley systems.

The table below details the primary functional categories for many common mechanical components. Most of these components are COTs but some will require significant work with suppliers to design. The following pages will detail the specification process for some of these components but not all. We will focus on the components that can be readily purchased without needing to work closely with suppliers to customize the component.

 

Table of the High-Level Common Mechanical Component Types and their Primary Functionality

 

Locate

Energy Storage

Energy Conversion

Energy Transmission

Threaded Fasteners

  • Bolts
  • Nuts and locking nuts
  • Grub screws
  • Studs
  • Screws
  • Expanding bolts
Springs

  • Compression
  • Extension
  • Torsion
  • Helical
  • Leaf
  • Flat
  • Belleville
  • Rubber
  • Spiral
  • Garter
  • Torsion bar
  • Wire form
Turbo Machinery

  • Gas turbine
  • Rotodynamic pumps and compressors
  • Fans
  • Propellers
  • Turbines
Gearing

  • Spur
  • Helical
  • Herringbone
  • Bevel
  • Miter
  • Worm
  • Conformal
Cylindrical

  • Washers, spacers
  • Retaining rings
  • Grooves
  • Tolerance rings
  • Snap Rings
  • Circlips
Thermal/fluid

  • Fluid accumulator
  • Gas spring
  • Reservoir
  • Pressure vessel

 

Chemical

  • Rotary
  • Reciprocating
  • Fuel cells
  • Rockets
Other Rotary

  • Cranks
  • Cams
  • Ball screws
  • Power screws
Pins

  • Cylindrical
  • Taper
  • Spring
Chemical

  • Battery
Thermal

  • Boilers
  • Heat exchangers
Belts and Chains

  • Flat belt
  • Vee belt
  • Wedge belt
  • Round belt
  • Synchronous belt
  • Roller chain
  • Leaf chain
  • Conveyor chain
  • Silent
Non-Threaded Fastening

  • Rivets
  • Nails
  • Adhesives
  • Welds
Mechanical

  • Fly Wheel
  • Solid mass
Electrical

  • Motors
  • Solenoids
  • Alternators and generators

 

Structures

  • Linkages
  • Pipes and hoses
Keys and Keyways

  • Flat
  • Round
  • Profiled
  • Gib head
  • Woodruff
Mechanical

  • Dampers and shock absorbers
  • Pumps
  • Pneumatic and hydraulic actuators
  • Brakes
Shape

  • Shoulders
  • Grooves
  • Fits

 

Motion Support

Stationary Support

Sense

Switch or Control

Seals

Rolling Element Bearings

  • Deep groove ball
  • Angular contact ball
  • Cylindrical roller
  • Needle roller
  • Tapperd roller
  • Self aligning
  • Thrust
  • Recirculating ball
Housings

  • Frame
  • Casings
  • Enclosures
Fundamental Properties

  • Motion
  • Dimension
  • Mass
  • Force
  • Torque
  • Power
  • Strain
  • Stress
  • Sound
  • Humidity
Clutches

  • Square jaw
  • Multiple serration
  • Sprag
  • Roller
  • Drum
  • Disk
  • Magnetic
  • Synchromesh
Dynamic Seals

  • Mechanical face
  • Lip ring
  • Bush
  • Labyrinth
  • Brush
  • Ferrofluidic
  • Rim seals
  • O Rings
  • Packings
  • Piston rings
Sliding Bearings

  • Plain rubbing
  • Hydrodynamic
  • Hydrostatic
 Structures

  • Grips
  • Guides
  • Clamps
  • Jigs
  • Hooks
  • Handles
  • Levers
Pressure

  • Pitot tubes
  • Static tapping
  • Manometers
  • Piezoelectric
Mechanical

  • Valves
  • Levers
  • Ratchet Pawl
  • Geneva and other index mechanisms
  • Triggers
  • Ballistic strips
  • Latches
Static Seals

  • Gaskets
  • O Rings
  • Sealants
Wheels, Rollers, Brushes, Pulleys  Temperature and Heat Flux

  • Thermocouples
  • Resistance
  • Thermometers
  • Pyrometers
  • Thermopile
  • Gardon gauge
Hinges, Pivots, Joints Mass Flow

  • Laser Doppler
  • Hot wire
  • Ultra sonic

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Introduction to Mechanical Design and Manufacturing Copyright © by David Jensen is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

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