The keyway cut into the shaft reduces the load carrying capacity of the shaft. This is due to the stress concentration near the corners of the keyway and reduction in the cross-sectional area of the shaft i.e. the torsional strength of the shaft is reduced.
What is the disadvantage of keyed joint?
Too much securely fixed keyed joint might become difficult to dismantle. Causes shaft imbalance. They introduce stress points due to the notch effect and reduce shaft strength. Possible axial displacement of hub unless locked by an extra component such as circlip or set screw.
What is a keyway cut?
A notch called a keyway is cut on the inside of the gear along with another notch cut, longways, into the shaft. Then and a piece, usually metal, called a key is inserted into the shaft keyway. The gear can then be fitted onto the shaft and the keyway on the gear will fit over the key, inserted in the shaft.
What is the purpose of a keyway?
A keyway is a long slot cut into a component to accept a key that engages with a similar slot on a mating component so that the two components do not move against each other. If the key is not fitting properly in both the flywheel and crank shaft keyways, replace the key.
Why key is used in shaft?
In mechanical engineering, a key is a machine element used to connect a rotating machine element to a shaft. The key prevents relative rotation between the two parts and may enable torque transmission.
How much torque can a keyway handle?
The limiting pressure point of a keyed shaft is the keyway side of the male shaft, provided the proper key material is selected. Thus, 270 Nm is the maximum torque that can be transmitted before the 19 mm diameter keyed shaft plastically deforms.
How do you get a keyway out of a shaft?
Place the assembly over the key, and then thread the bolt into the shaft as far as it will go. Spin the nut downward against the block. Then use a wrench to apply enough force on a nut to remove the key from the shaft. If you apply enough downward movement, the key will be extracted.
Which key is used in automobile shaft?
Explanation: Normally in Automobile shafts Woodruff key is used.
What is a keyway in construction?
a groove in a shaft, the hub of a wheel, etc., for receiving part of a key holding it to another part. a slot in a lock for receiving and guiding the key. (in poured-concrete construction) a longitudinal groove in a footing, or in a pour that has set, providing a key for newly poured concrete.
Which is act on shaft?
Which of the following act on shafts? Explanation: Shaft is subjected to torsional moment as well as bending moment. 9.
Which type of the key used on the shaft and hub?
Taper sunk keys
– Straight-ended sunk keys, also called tapered driving keys – in this case the shaft and the hub (or the machine parts in question) are mounted as in normal use and the sunk key driven in subsequently. They are used if there is sufficient space to drive them in and out from either side.
What is the consideration for design of the shaft?
Things to Check in a Shaft Design
Static stress The shaft must withstand stress that results from applied loads and torque. This could also include the weight of attachments such as gears and flywheels. Deflection Excessive deflection can cause problems such as gear mesh.
How can a keyway be machined on a shaft?
A method of machining keyways in shafts comprises the steps of aligning a central line of a spindle of a machine tool with a center line of a shaft to be machined, preliminarily machining a keyway in the shaft with keyway mill arranged on the spindle so as to retain a symmetrical allowance for a finishing machining of
What is the primary purpose of the clearance or gap between the key and the keyway?
To ensure that the hub seats properly on its shaft, provide some clearance between the key and the bottom of the hub keyway. In the case of a coupling hub, this clearance provides an opening through which water or corrosive gases can enter the coupling, causing damage to its internal surfaces.
What are shaft keys made of?
Typically, shaft keys are made from either medium carbon steel or stainless steel. But they can be made from many different types of material such as aluminium alloy, bronze, copper, and brass to suit different application environments.
How long should a shaft key be?
The key and key seat cross section are ISO standardized. The key length should be less than about 1.5 times the shaft diameter to ensure a good load distribution over the entire key length when the shaft becomes twisted when loaded in torsion.
How is torque transmitted?
A gear’s transmission torque changes as it increases or decreases speed. Generally, by reducing the speed, a small torque at the input side is transmitted as a larger torque at the output side. The calculation of torque depends on the number of teeth.
Which stresses are induced in the key due to transmission of torque from shaft to hub?
Forces (F) due to the torque transmitted by the shaft. These forces produce shearing and compressive (or crushing) stresses in the key.
What is feather key?
Definition of feather key
in machinery. : a sunk key without taper that is permanently fixed in one of the connected pieces and that is a sliding fit in a keyway in the other so as to permit relative longitudinal motion. called also spline.
What is a crankshaft key?
Crankshaft keys (also called woodruff keys) are semicircular shaped, removable keys that fit into matching keyways cut into the crankshaft leaving protruding tabs. These tabs mate with matching slots on the harmonic balancer flush upon the shaft.
What type of key is used when the gear is required to slide on the shaft?
parallel key
It may be noted that a parallel key is a taperless and is used where the pulley, gear or other mating piece is required to slide along the shaft. It is a rectangular sunk key with a head at one end known as gib head. It is usually provided to facilitate the removal of key.
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