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A 15 kW, 960 r.p.m. motor has a mild steel shaft of 40 mm diameter and the extension being 75 mm. The permissible shear and crushing stresses for the mild steel key are 56 MPa and 112 MPa. Design the keyway in the motor shaft extension. Check the shear strength of the key against the normal strength of the shaft. Solution. Given :
d = Diameter of shaft, l = Length of key, w = Width of key, t = Thickness of key, and and c = Shear and crushing stresses for the material of key. A little consideration will show that due to the power transmitted by the shaft, the key may fail due to shearing or crushing.
The shearing and crushing stresses for the key material are 42MPa and 70 MPa. Given data: d = 50mm; τ = 42MPa = 42N/mm2; σc = 70MPa = 70 N/mm2 From the table we find that for a shaft of 50mm diameter Width of the key w = 16mm; thickness of key t = 10mm The length of the key is obtained by considering the key in shearing and crushing.
Crushing Plant Design and Layout Considerations - 911 Metallurgist. In mining operations, the layout of crushing plants and ancillary equipment and structures is a .. The life of the mine is a key element in the design of any crushing plant. . Supports must be provided for gyratory and conveyor main shafts and Quarry. Hinton,AB. 54 x 74 AC. 1.
For designing a rectangular key for a shaft of d=80 mm, find the length of the key in mm if shearing stress for key and shaft =147 MPa and crushing stress =283 MPa. let key width w =d/4 mm and key thickness t=d/6 mm. Show transcribed image text.
A saddle key, shown in figure- is very similar to a flat key except that the bottom side is concave to fit the shaft surface. These keys also have friction grip and therefore cannot be used for heavy loads. A simple pin can be used as a key to transmit large torques. ... Crushing failure of key: 6) shearing failure of key 7) The material of key ...
KEYS: A key is a piece of mild steel inserted between the shaft and hub or boss of the pulley to connect these together in order to prevent relative motion between them. It is always inserted parallel to the axis of the shaft. Keys are used as temporary fastenings and are subjected to considerable crushing and shearing stresses.
Assuming an allowable crushing stress for the key material to be 100MPa, the key design is safe. Therefore the key size may be taken as: a square key of 6.25 mm size and 37.5 mm long. However keeping in mind that for a shaft of diameter between 22mm and 30 mm a rectangular key of 8mm width, 7mm depth and length between 18mm and 90mm is recommended.
A key is a piece of mild steel inserted between the shaft and hub or boss of the pulley to connect these together in order to prevent relative motion between them. It is always inserted parallel to the axis of the shaft. Keys are used as temporary fastenings and are subjected to consider-able crushing and shearing stresses. A keyway is a slot
Jul 06, 2020· Crushing mode of failure at key-shaft or key-hub interface. The key is in contact with shaft and hub as shown in Fig. 9. The key may crush at this area leading to failure of key. The failure will take place on the component whose resistance to crushing is less. The resistance to crushing depends on the area in contact and the design crushing ...
Nov 13, 2015· w = key width (m) l = keyway effective length (m) F = 390 x 10 6 * 0.006 * .032. F = 74,880 N. T = 74,880 * .009. T = 673.9 Nm. Crushing Failure. The second possible mode of failure, also caused by forces exerted on the key by the shaft and hub, is based on compressive forces, which can induce permanent deformation and crush the key.
Key acts as a safety device, whenever there is excess load appears on the pulley key fails first and it keeps safer to shaft and pulley. It is always inserted parallel to the axis of the shaft. Keys are used as temporary fastenings and are subjected to considerable crushing and shearing stresses.
Aug 12, 2018· d = Diameter of the shaft, w = Width of the key, h= Height of the key, l = Length of the key. τ = Shear Stress for the material of the Key. σ c = Crushing stresses for the material of the key. So the total torque transmitted by the shaft (T) = F × d/2 (Eqn 1) The Tangential force acting on the key …
Keys And Pins – : Read Books Online for Free. Sc = Safe crushing ober stress (lbs. per bo. in.). …crushing being exerted by the side of the key in both shaft and hub, over the area against the key…
Crushing failure of flat keys F F t/2 t/2 2 t L F Sc = S c = compressive stress (lb/in2) = S y t = total height of the key (in.) S t D 4 T L c = D 2T F = August 15, 2007 10 Example Problem 15-1: Design of Keys • A ½-inch shaft transmits 5 hp at 1750 rpm. • The shaft is made from cold-drawn 1040 steel; hub is made from hot-rolled 1213 steel ...
Oct 10, 2015· Keys are used as temporary fastenings and are subjected to considerable crushing and shearing stresses. A key way is a slot or recess in a shaft and hub of the pulley to accommodate a key. Types of Keys: The following types of keys are important from the subject point of view : 1. Sunk keys, 2. Saddle keys, 3. Tangent keys, 4. Round keys…
The key is designed with usual proportions and then checked for shearing and crushing stresses. The material of key is usually the same as that of shaft. The length of key is taken equal to the length of hub. 3. Design for flange The flange at the junction of the hub is under shear while transmitting the torque. Therefore, the torque transmitted,
Jul 16, 2012· As the industrial arena grows more sophisticated, it seems as though operations are confronting fewer and fewer broken machine shafts. When shafts DO break, however, there are almost always as many theories regarding the suspected culprits as there are people involved. Fig. 1 The appearance of an overload failure depends on whether the shaft material …
Key dimensions: Parallel keys are most commonly used. 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.
Jul 09, 2010· Shows many types of failure for the coupling (key shearing, shaft crushing, hub crushing, shaft breaking) look at my website for more details and data.Montre...
according to the number of the working shafts (Tonkov 2007), and the technology of crushing: single-shaft, two-shaft, three-shaft, four-shaft, five-shaft shredders, with varying automation degrees and key parameters control, noise different level, rotation speed, pressurization level …
Aug 10, 2018· The key will have a provision in both the shaft and the machine element which needed to be connected. this is called Keyway. These keys are temporary fastening elements and are subject to the crushing and the shearing stress. There are different types of the keys available. Different types of Keys in Machine Design
Cross-section of the key is taken from the table corresponding to the shaft diameter or relations (square key) or and (for rectangular key) are used to find the cross-section, where w is width and h is the height of the key. Length of key in each shaft, . The keys are then checked in shear and crushing.
Aug 03, 2018· In order to find the length of the key to transmit full power of the shaft, it can be used the equation (i) and eqution (ii). Example. Design the rectangular key for a shaft of 50 mm diameter. The shearing and crushing stresses for the key material are 42 MPa and 70 MPa. Solution. Given : d = 50 mm ; τ = 42 MPa = 42 N/mm 2 ; σc = 70 MPa = 70 ...
Keys and Coupling Introduction A key is a piece of mild steel inserted between the shaft and hub or boss of the pulley to connect these together in order to prevent relative motion between them. It is always inserted parallel to the axis of the shaft. Keys are used as temporary fastenings and are subjected to consider-able crushing and shearing stresses.
Keys and keyways prevent the shaft fron rotating on the bore and can assist in torque transmission between the two connected shafts. Key, Keyway, and Keyseat A key is a piece of metal used to connect a rotating machine element to the shaft. A key ...
Feb 23, 2020· F S = Shear force on the key. D = Shaft diameter. By crushing of key. The crushing force acting on a key due to transmission of torque ({T_C} = F_C times frac{D}{2} ) Where T C = Torque transmitted by the coupling (N-mm) F C = crushing force on the key. D = Shaft diameter. The key is equally strong in shear and crushing when T C = T S.
Both keys must be checked, although experience has shown that small diameter shafts are more prone to failure of the key and keyway when these precautions are not followed because of their normally smaller key width and length of engagement. Maximum Allowable Shear Stress. Material. Stress, psi. Aluminum. 4000. Cast Iron. 4500. Ductile Iron.