The hub is slightly larger than the shaft and key to allow it to slide over the shaft during assembly. Transmitting torque with keyed shafts linear motion tips. Machine design applications gear design data and engineering. Keys aroused as temporary fastenings and are subjected to considerable crushing and shearing stresses. The shearing and crushing stresses for the key material are 42 mp and 70 mpa. We stock pre keyed shafting in many diameters, including metric diameters, with. A 600mm diameter pulley is mounted at a distance of 300mm to the right of left hand bearing and this drives a pulley directly below it with the help of belt having maximum tension of 2250 n.
Among these, the most common is the parallel key that is the subject of the present paper. For minor shock loads a factor of safety of 2,5 should be used and one up to 4,5 should be used for high shock loads especially if the loads are reversible. Design of square key and keyway wood ruff stress, shear. A 58, 34, or 1inch keyed shaft are common sizes, and the dimensions of a matching key, such as 316x332inch, are standardized as well. Shaft and hub keyway and key sizes keys connecting shafts to pulley hubs are commonly used to achieve reliable noslip power transmission in belt drive systems.
Charts of theoretical stressconcentration factors k. In addition to keyed shafts, zoro offers woodruff keys, shaft collars and a host of couplings as well. In other words, a square key is equally strong in shearing and crushing. To accommodate the key into the shaft a slot is cut into the. Design based on rigidity is to ensure that maximum deflection because of bending and maximum twist due to torsion of the shaft. Design text, keyways and pin joints always provide positive mechanical engagement for torque transmission.
For a key to function, the shaft and rotating machine element must have a keyway and a keyseat, which is a slot and pocket in which the key fits. Shafts are designed on the basis of strength or rigidity or both. The shaft design is the din standard presented in figure 2. Allowable shear stress for the material of the shaft. Stress concentrations in keyways and optimization of. Standard inch series bores and keyways data sheet ds103.
To demonstrate, below is an example of the maximum torque that can be transmitted by a keyless shaft. Keyed shafts come in a wide variety of lengths, diameters and materials, so determine your preferences before you shop. Design optimization and verification skf can work with you to optimize current or new designs with proprietary 3d modelling sof tware that can also be used as a virtual test rig to confirm the integrity of the design. Download fulltext pdf download fulltext pdf optimization of the keyway design with consideration of effect of stress concentration on different materials article pdf available april 2014. Partial keyways and other materials are available, including turned and polished, and medium carbon steel suitable to heat treat. Design based on strength is to ensure that stress at any location of the shaft does not exceed the material yield stress. N l pedersen 1 work on effect of stress concentration and optimization of keyway design using numerical finite. Shaft couplings and universal joints universal joints singleuniversaljointstypesgandh, shafts6to50mm. Dimensions of shaft keys, standardized many years ago, are commonly considered to be the main concern in applying these devices. The diagram shows six different keyway and pin joint arrangements. The key and key seat cross section are iso standardized.
Highspeed shafts require not only higher shaft stiffness but also stiff bearing supports, machine housings, etc. Highspeed shafts must be carefully checked for static and dynamic unbalance and for firstand secondorder critical speeds. Using this formula the toque acting on the shaft is calculated. The main objective of the paper is to write a generalised program using c programming language applicable for design of all transmission shafts with mountings. It is always inserted parallel to the axis of the shaft. Design the rectangular key for a shaft of 50 mm diameter. Shop a large range of keyed steel shafting at msc industrial supply. The key and keyway design is fully controlled by the standards based on only one parameter the shaft diameter. Commonly keyed components include gears, pulleys, couplings, and washers. Precision cut keyed c1018 cold drawn shafting shaft size. We stock pre keyed shafting in many diameters, including metric diameters, with standard keyways.
The maximum allowable torque a keyed shaft can transmit is. Determine torque in shafts from gears, pulleys, sprockets, clutches, and couplings. Design of transmission shafts using c programming language. Msc industrial supply is here to support all your metalworking and maintenance repair needs with over 1 million products in stock and ready to ship today. And of course, the smaller the diameter, the less torque can be transmitted before failure occurs. Shaft shown drives a gear set that is transmitting 5 hp at 1750 rpm. Numerical problems on shaft design 1 a shaft is supported by two bearings which are placed 1m apart. Design of square key and keyway wood ruff stress, shear and.
Set screws, along with the press fit interaction between the bore and shaft, are relied upon to secure the hub to the shaft. Optimization of the keyway design with consideration of. We can provide keyed shafts in any length up to 20 foot. Keyed connections, however, do have a drawbackthey require a reduction in shaft diameter of the torquetransmitting component. A keyed shaft is used in power transmission applications to secure the rotation a pulley or gear hub to that of the shaft and as a safety mechanism in which the key will shear to prevent further damage to the hub or shaft. The diameter of shaft for flywheel is obtained from the maximum torque transmitted. An important consideration in setscrew size selection is. For this use in calculation and design, it was thought best to coin a term to permit comparison between a shaft with keyway. A key with a square end is likely to damage the shaft when transmitting torque, figure 5. Shaft stress calculations shaft 1 diameter38 material. Shaft is supported in selfaligning ball bearings and gears are both 10 pitch, 40 tooth, 20 spur gears. Design of square key and keyway wood ruff stress, shear and torque equations and calculator. This type of arrangement is generally sufficient for very light loads.
Where of is the overload or service factor, for example if the maximum torque is 20% more than mean torque then of should be taken as 1. Keyed shafts are commonly made of high precisiontolerance carbon steel but the requirements of an application in a corrosive environment may call for a stainless steel keyed shaft. Keys 4 a key is the piece inserted in an axial direction between a shaft and hub of the mounted machine element such as pulley or gear etc. Pdf problem set 8 chapter 17 shafts selected problems. Because the stress distribution for keyed connections is not completely understood, a factor of safety of 1,5 should be used when the torque is static.
It is remarkable that very little effort has been made to improve the design. Msc industrial supply is here to support all your metalworking and maintenance repair needs with over 1 million products in stock and. Trukey shafting from keystone is designed to provide the straightest, most accurate keyed shafting, in the industry. Design tapered keys designed to be inserted from the end of the shaft after the hub is in position. Mechanical power transmission hub design hubs are used to transmit mechanical power from a drive motor by coupling it to an output device such as a wheel or an arm. Different design principles are possible, these include parallel keys, tapered keys or woodruff keys, see e. Nov, 2015 keyed connections, however, do have a drawbackthey require a reduction in shaft diameter of the torquetransmitting component. Note the following points concerning the customers solid shaft. Pdf optimization of the keyway design with consideration of. You can also shop for shaft adapters and motor parts.
They are categorized by drive type and point style. A keyed shaft works in unison with a rotating machine element to transmit torque to power transmission components. Let d diameter of the shaft width of the key w d4 rectangular crosssection nominal thickness h 23w 16d square crosssection. Stress concentrations in keyways and optimization of keyway. Compare combined stresses to suitable allowable stresses. In mechanical engineering, a key is a machine element used to connect a rotating machine element to a shaft. The corner of the key creates a high contact stress in the. Shaft keys are important machine components designed to transmit torque and rotative force. Keys and keyways commonly perform connection of shaft and hubs.
Keys design 6 keys are sunk in the shaft and the hub. The rectangular key is designed for a shaft of 50 mm diameter, width of key, 4 d w, w 12. To demonstrate, below is an example of the maximum torque that can be transmitted by a keyless shaft, compared with. The bottom edge is a symmetry line so here the dirichlet boundary condition. Metric standard parallel keyway and key sizes shaft diameter mm keyway mm key mm from to width w depth h width w depth t 6 8 2 1. Find bending moments from gears, pulleys, or sprockets that are transmitting loads to or from other devices.
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. In order to find the length of the key to transmit full power of the shaft, the. Shaft design based on strengthshaft design based on strength ai l t ti axial stress continue. Keyed shaft the limiting pressure point of a keyed shaft is the keyway side of the male shaft, provided the proper key material is selected.
A keyed joint may allow relative axial movement between the parts. Pdf the objective of this chapter is to introduce the concepts and principles of shaft design. To accommodate the key into the shaft a slot is cut into the shaft which is known as the keyway. There are several types of shaft keys, each with their own particular role and application. The key and keyway design is fully controlled by the standards based on only one parameter, the shaft. We have a complete line of highquality redi keyed shafting ranging from inch to metric sizes, along with the accompanying keystock that goes with redi keyed shafting right of the shelf. A keyway is a squarecorner channel that runs the length of the shaft and of the hub, intended to hold a short rectangular. This 1 14 keyed shaft is a high quality, durable, and economically priced shaft that is stocked as 3ft, 6ft, or 12ft long keyed fulllength steel shaft, but can be cut to length in one to two business days. Figure 1 shows an exploded view of a typical motorhub wheel. Some sizes may be full or semicounterbored or step cut at manufacturers option. The key prevents relative rotation between the two parts and may enable torque transmission.
Clockwise or counter clockwise model code gear design pg displacement xxxx style a rotation x frame 505 pump p shaft j1 shaft end cover h1 seal material n side inlet d3 side outlet d2 rear outlet b1 rear inlet b1. Shaft keys, shaft key design, rectangular keys, square keys, woodruff keys, gib keys, taper keys. Setscrews are semipermanent fasteners that hold collars, pulleys, or gears on shafts. The design of shafts in some cases, such as those for turbopumps, is dictated by shaft. In smaller minimum plain bore style pulleys, keys are not used. Among these, the most common is the parallel key, whichisthesubjectof thepresentpaper. The notch factor gives a rough value of how the stress is increased in the keyway. To find diameter of shaft to transmit required torque. The taper will impart a compressive contact pressure between the hub and the shaft. Deflection of the shaft, both linear and angular, should be checked at gears and bearings. Hollow shaft with key standard design design and operating data 116 gear units 2016 7. The hub is slightly larger than the shaft and key to allow it to slide over the shaft during.
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