Couplings Flashcards
Types of couplings
- rigid
- flexible
- special purpose
Shaft couplings
-power transmission components used to connect the driving and driven shaft end to end
Rigid coupling
- provides a fixed union between two shafts
- doesn’t allow for any deviation in alignment between the two shafts.
- has no provision for end float
Types of rigid couplings
- sleeve
- compression/flange
- ribbed/muff
- flange face
- threaded
Sleeve Coupling
- very simple rigid coupling used at low speeds and low torque
- has set screws
Compression or Flange coupling
- Wedging action connects the coupling to the taper on the shaft
- Grip the shaft by using tapered sleeves in tapered hubs so when they are drawn together they clamp to the shaft
- handle light or moderate loads
- shafts can be the same or different diameters
Ribbed or “Muff” coupling
- Used in heavy load or torque services
- have machined key ways in both shafts
- clamping forces keeps all the parts together but the torque is transmitted from the keys
- easy to remove and reconnect
Flanged face or “spiggett & recessed” coupling
- can connect both the same diameter & different diameter shafts
- the flange halves are made with male female hubs
Threaded couplings
-A special type of rigid coupling commonly used on vertical pumps where the drive unit is connected to the pump by a series of drive shafts joined by threaded coupling
The direction the shaft rotates on a threaded coupling?
-in the direction of thread of the coupling
How big of gap should be between the coupling halves on rigged and other split couplings?
-1/16 to 1/8
Rigid multibore
-Made for shafts with different diameters
Flexible couplings
- most common coupling
- compensate for some misalignment
Classifications of flexible couplings
- mechanical flexibility
- material flexibility
- combination flex
Mechanical Flexibility
- permit limited flexibility by allowing the coupling components to move relative to each other.
- they have sufficient internal clearances to allow for movement
Types of mechanical flex couplings
- roller chain
- silent chain
- synthetic chain
- gear
Chain coupling
- very easy to disconnect
- chain can be replaced without moving either the drive or driven shaft
- the clearance between the chain, sprocket teeth and internal clearance allows for some misalignment
- 1/4 axial travel in some cases
Roller chain coupling
- have two sprockets keyed to the shafts connected with a length of standard pitch
- flanges which are cut to receive roller bushing
- suitable for moderate speed & power applications
Most common roller chain
-double strand roller chain
Single Strand roller chain
-allows for more end float in your drive because of the absence of the pin link and roller link plates in the centre of the chain
Silent Chain Coupling
- heavy-duty drives at speeds of up to 5000RPM
- allow for very minor misalignment and some endplay
- remain in balance at high rotational speeds