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Alignment & Couplings. 3 methods to perform basic alignment: Straightedge and feeler gauge Dial indicator Reverse indicator Straightedge and Feeler Gauge Least accurate Used when accuracy not critical Easy to perform. Alignment & Couplings. Dial Indicator Method
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Alignment & Couplings • 3 methods to perform basic alignment: • Straightedge and feeler gauge • Dial indicator • Reverse indicator • Straightedge and Feeler Gauge • Least accurate • Used when accuracy not critical • Easy to perform
Alignment & Couplings • Dial Indicator Method • Called “Rim and Face” Method • Uses dial indicator to measure parallel and angular misalignment • Accurate alignment (i.e. rigid couplings) • Probe location: • Coupling face – angular misalignment • Coupling rim – parallel misalignment
Alignment & Couplings • Reverse Indicator Method • 2 dial indicators, one on each shaft • All measurements from the rim of the couplings • Most accurate of the 3 methods • Coupling does not have to be disassembled
Alignment & Couplings • Couplings • 6 Most Common Type • Flange • Flexible Sleeve • Chain • Gear • Grid • Universal Joints
Alignment & Couplings • Flange Couplings • Rigid couplings with 2 assembled flanged hubs • Fixed by a series of cap screws • Assembled with fixed tapered bushing • Used in heavy duty applications • Advantages: • Low maintenance • Ease of installation • Ease of removal • Lubrication free
Alignment & Couplings • Flexible Sleeve Couplings • “Donut” Couplings • Rubber sleeve with external and internal teeth with mating teeth on two hubs • Flexibility from resilient material • Neoprene • Polyurethane • Good to dampen shock and vibration
Alignment & Couplings • Chain Couplings • Moderate/low torque and speed applications • 2 sprockets and chain wrapped around teeth • Sealed cover to retain lubricant • Advantage: • Chain can be replaced without moving the shafts • Chains must be lubricated
Alignment & Couplings • Gear Couplings • Flexible • High torque, high speed applications • 2 hubs with external teeth joined by a sleeve (flange) made of nylon or steel • Flexible due to movement within the teeth • Lubrication • Nylon sleeve – none • Steel – oil/grease
Alignment & Couplings • Grid Couplings • High torque, high speed applications • Large pumps and bulk conveyors • 2 hubs with slots joined by a metallic grid • Covered to retain lubricant • Limited misalignment allowed • Lubricant - grease
Alignment & Couplings • Universal Joints • U-joints • Power must be distributed between shafts at an angle larger than allowed by flexible couplings • Cars – join drive shaft to differential • Simplest/Common – Block and pin • Singular U-joint – Angular Offset • Double U-Joint – Parallel Offset
Lubrication • Every machine with moving parts experiences Friction. • Friction causes: • Premature wear • Excessive heat • Lubricants (oils and greases) control friction
Lubrication • Oils • Natural or synthetic liquid • Most important property – Viscosity • Viscosity – resistance to flow at a given temperature • Higher temp – lower viscosity • Lower temp – higher viscosity • Viscosity measured by – viscometer • Standardized – SAE (Society of Automotive Engineers) • 8 viscosities - SAE 5W (low viscosity) SAE 50 (high viscosity) • W is for winter use
Lubrication How to Read the Oil Grades The grades assigned by the SAE are formatted with a first number followed by a "W" and then a second number. The first number, along with the "W," signifies that the oil is suitable for winter use because it remains thin even in the cold. For example, 5W is suitable for use in temperatures as low as -25 degrees Celsius, 10W for temperatures as low as -20 degrees Celsius, 15W for -15 degrees Celsius and 20W for -10 degrees Celsius. A 0W oil was recently developed and is used primarily in workshops, given its higher price tag. However it is sometimes used in places such as Canada that have extremely harsh winters. The second number indicates how the oil will perform in very hot temperatures---the goal is to keep the oil from getting too thin because thicker oil performs better in heat. These numbers range in multiples of 10 from 10 to 60, with 60 being the thickest. Oil that is graded 5W-60 is the most versatile oil that is widely available. It has the highest resistance to thickening in the winter and the highest resistance to thinning in the summer.
Lubrication • Grease • Semi-solid lubricants • Combination of oil, thickening agent and additives • Preferred when: • Lubricant retention • Re-lubrication • Consistency – degree to which it resists deformation under application of force • Consistency is divided into grades by NLGI • National Lubricating Grease Institute • Grades: • 000 – softest • 6 - stiffest
Material Safety Data Sheet (MSDS) • OSHA requires every chemical have MSDS • Documents all hazardous contituents and list ways to: • Prevent • Control injuries • Illness • OSHA sets the minimum information • Format not standardize • Each manufacturer has own presentation
Material Safety Data Sheet (MSDS) • Typical MSDS Sheet includes: • Identity and Emergency Information • Hazardous Ingredients • Physical Data • Fire and Explosion Hazards • Health Hazards • Reactivity • Spill or Leak Procedures • Special Protection • Special Precautions Link: http://support.radioshack.com/msds.htm#160
