Couplings, Brakes, and Clutches Flashcards
What are the 3 basic types of couplings?
Rigid
Flexible
Special purpose
What type of connection do rigid couplings provide?
Fixed union
(Shaft extension)
What are the 5 types of rigid couplings?
Sleeve
Compression
Ribbed
Flange face
Threaded
What type of applications are sleeve couplings used?
Low speed
Low torque
How are sleeve couplings attached to the shafts?
Keyway and set screws
How are compression couplings attached to the shaft?
Using tapered sleeves and hubs
What applications are compression couplers used in?
-Light to moderate loads
-Where the coupling must be installed/removed frequently
What applications are ribbed couplings used?
Heavy load
Heavy torque
How are ribbed couplings attached to the shaft?
Compression from the bolts
Keyway
What type of coupler is this?
Ribbed coupling
What type of coupler is pictured?
Sleeve coupling
What type of coupler is pictured?
Compression coupler
What is a rigid multi bore coupler?
A ribbed coupling for two different sized shafts
How are flange face couplings attached to the shaft?
Heavy interference or taper fit
What applications are flange face couplings used in?
Light application
What coupler is pictured?
Flange face coupler
What are threaded couplers used for?
Mainly with pumps or vertical positions
What type of coupler is pictured?
Threaded
What is the main benefit of using a flexible coupling?
Compensate for some misalignment
What are the 3 ways flexible couplings are classified?
Mechanical flexibility
Material flexibility
Combination
What are the 4 types of mechanical flexible couplings
Roller chain
Silent chain
Synthetic chain
Gear
What are the 3 types of chain couplings?
Roller
Silent
Synthetic
What are the characteristics of chain couplings?
-Mechanical flexibility
-Limited torsional, shock, and vibration dampening capabilities
What are the 2 type of roller chain couplings?
Double
Single
What coupler is pictured?
Single roller chain coupling
What applications are silent chain couplings used for?
Heavy duty
What speeds can silent chain get to?
Up to 5000rpm
What are the disadvantages to silent chain?
Very minimal amounts of misalignment
Flexibility is very limited
What applications are synthetic chains used for?
Light power transmission drives
What type of coupler is pictured?
Silent chain
What applications are gear couplings used for?
Extremely high torque
High rpm’s
What is the benefit of curved tooth gear couplings?
Tolerate more misalignments
What are the 4 most common material flexible couplings?
Rubber tire couplings
Elastomeric couplings
Pin and biscuit couplings
Flexible metal disc couplings
What is the main disadvantage to material flexible couplings?
Shorter service life
Which type of coupling must have misalignment less than bearing tolerance?
Rigid
The input shaft of a fluid coupling is connected to which component?
Impeller
What is the purpose of a fluid coupling?
To allow the driver to come up to speed before engaging
Allowing the prime mover to reach a set running rpm before applying load using a clutch is known as ___________
A soft start
A shaft with universal joints on each end and a splined slip joint is best used when
Angular, offset and or axial misalignment is present
What is the main advantage of a flexible coupling over a rigid coupling?
They compensate for minor misalignment
What style of coupling is commonly used on vertical pumps?
Threaded coupling
What are the 3 styles styles of universal joints?
Double joint
Single joint
constant velocity
Where are silent chain couplings mainly used?
High speed
High torque
What must be done in terms of maintenance with a steel grid coupling
Must be lubricated
What is another name for a scoop coupling?
Variable fill
What do we call a short length of shafting coupled on each end with no bearing support?
Floating shaft
What coupling increases initial torque on engagement?
Torque converter
What is hysteresis
Lagging magnetism as the coupling turns
What is a disadvantage of positive contact clutches?
Engagement must be done at low speeds
What is the purpose of a fluid coupling?
To allow the driver to come up to speed before engaging
What is a backstop device on an inclined converter?
A one way brake on the roller drive
Brakes or clutches would be classified as electrical operation when what principles are used?
Magnetic or magnetic particle principals
What would a brake use to stop a piece of rotating machinery
Friction or magnetism
How many directions can a spiral clutch operate?
One
What type of clutch has no slippage on engagement and allows bidirectional power transmission?
Multi tooth clutch
What type of drum clutch has contact on the inside diameter to force engagement?
Expanding
Cone clutches typically use a drum and pad engagement angle greater than _____ degrees
10
What force is used when a brake is applied to keep the machine parts at rest?
Static friction
What friction clutch uses a wedging action for engagement?
Cone clutches
What type of device is purposely used to engage and disengage two shafts without physically dismantling machinery?
Clutches
Jaw style clutches assure positive drive with ____________
No slippage
What is sprag?
A cammed roller or wedge
When will friction clutches do their most slipping?
On engagement
What do torque limiting clutches when they become overloaded ?
Slip
Is a threaded coupling a centrifugal coupling?
No
What effect reduces brake stopping efficiency?
Brake fade
Which friction clutch uses expanding or contracting shoes?
Radial clutch
When can friction clutches be engaged?
Anytime regardless of driven and driver speeds
What do brakes use to work effectively?
Friction
What is needed most of braking a heavy load for a prolonged time?
Lots of cooling capacity
What will increase the torque capacity the most in an axial clutch with limited diameter
Increase number of friction plates
What coupling used material flexibility to transmit power and deal with minor misalignment
Quill coupling
Where are silent chain couplings mainly used?
High speed
High torque
What is an example of a typical back stop device on an inclined conveyor?
A one way brake on the roller device
When can friction clutches be engaged?
Anytime regardless of driven and driver speed
What is needed if braking a heavy load or for prolonged periods of time?
Lots of cooling capacity
What actuates a pneumatically actuated brake or clutch
Air pressure
