Majid Yaghoubi

• Doctor of Engineering
• University of Tehran

Using this book, you can easily perform the most complicated calculations of machine elements in a few minutes and quickly.

One of the most time-consuming calculations in designing machine elements is related to bolts and nuts. In this chapter, an attempt has been made to simplify the calculations of bolts and nuts using the graphical method. In designing, at first, a bolt with a specific diameter is chosen based on the applied force. Then, it is checked to figure out w...

Design of power screws includes determining the diameter and pitch based on the applied force. They are two important characteristics of power screws. Table ‎6 1 presents the standard diameters of power screws together with their corresponding pitches. In this book, we consider sliding power screws with the Acme threads and ball screws and provide...

In this chapter, we propose unique methods that give very good approximations and easy calculations for the design of press-connect joints.

When two elements with curved surfaces make contact with each other and are pressed together, contact stresses (also called Hertzian contact stresses) are developed within the contact areas. Practical examples include the contact between wheels and rails, valve cams and tappets, mating gears and rolling bearings. .... In this chapter, we propose...

An overhead crane or bridge crane is a type of lifting equipment that consists of one or two parallel beams that are used to lift loads by hoist. The hoist may be installed above or below the beam (Underslung cranes). Designing overhead cranes is very time-consuming, but we provide unique diagrams and methods that facilitate their design and provi...

An overhead crane or bridge crane is a type of lifting equipment that consists of one or two parallel beams that are used to lift loads by hoist. The hoist may be installed above or below the beam (Underslung cranes). Designing overhead cranes is very time-consuming, but we provide unique diagrams and methods that facilitate their design and provid...

Mechanical design of machine components requires performing calculations using formulas, which is usually a sophisticated and time-consuming procedure. This book aims to provide students, engineers, practicing engineers, technicians and manufacturers, and machine builders with an easy-to-use reference; which is based on using graphs instead of comp...

The second edition of the book "Mechanical Design of machine elements by graphical methods" under the name "Design of Machine Elements by Graphical Methods for Engineers and Machine Builders" is available for order on the Amazon site: https://www.amazon.com/s?k=Design+of+Machine+Elements+by+Graphical+Methods+for+Engineers+and+Machine+Builders&i=str...

This book covers designing of various machine elements and serves as a reference for mechanical designing of machine elements in academia and industry. It provides information on designing approaches and several examples and problems, enabling readers to make all of their required calculations for their specific mechanical design or fabrication tas...

A shaft is an important machine element that transmits rotational power and/or motion. Components such as gears, pulleys, flywheels, cranks, sprockets and couplings, are mounted on or attached to the shaft in order to perform the transmissions. Shaft design involves specifying suitable dimensions for the shaft that ensure its satisfactory and safe...

A key is a detachable component used to connect a shaft and the hub of a power-transmitting element, which enables the transmission of torque and power between them. Designing the key includes determining its dimensions (height (h), width (b) and length (L)) according to the transmitted torque (T) and the shaft diameter (dsh). Equation ‎8 1 (see se...

A chain drive is a common type of flexible drives. It is used for power transmission between shafts that are relatively far from each other. In this chapter, we discuss the design of both roller, bush and silent chain chains. Using this method, you can easily design chain power transmission systems including the suggested number of sprocket teeth (...

Welded joints are one of the most common types of permanent joints. Main welded joint designs are butt, lap, T-, edge and corner joints. Basically, there are two types of weld seams; butt welds, which are used to connect elements within a plane and fillet welds, which are used to join components in different planes. The calculations of welded joint...

Wormgear drives are used to transmit power and motion between shafts whose axes are neither parallel nor intersecting. A worm gearset is composed of a worm that resembles a power screw, in mesh with a wormgear having a similar appearance as a helical gear. Worm gearing are often used for applications in which the speed ratios are quite high (up to...

Gears are toothed wheels that are widely used for power and motion transmission between rotating shafts. Based on the relative position of the shafts, gear drives can be fell into three principal categories, namely parallel-shaft gear drives, intersecting-shaft gear drives, and crossed gear drives. Parallel-shaft gear drives are the most common typ...

The common method for designing a machine, is that each component is designed separately, and then they are assembled. Especially for the power transmitting elements, which are associated with each other, this is a very time consuming process. In this chapter, we propose a method to design and calculate shafts and their attached components all toge...

Bevel gear drives are used to transmit or transfer power or motion between intersecting shafts. The teeth of bevel gears are machined on conical surfaces. There are two primary types for the teeth of bevel gears, namely, straight and spiral. In this chapter, we propose methods for designing straight and spiral bevel gears in a simple way.

Joining elements through press-connect creates durable and permanent connections that can transmit large and abruptly applied loads or fluctuating forces. Since this kind of joining does not require any connecting parts such as keys and consequently any keyways or grooves in which the stress concentration occours, it has a high design strength (ope...

Pins are generally subjected to bending, crushing, and shearing stresses. All these stresses must be taken into account for their design. This chapter deals with designing pin joints using unique proposed graphs that simplify the design of pins. However, our proposed method is the M.Y method.

Couplings are components used to connect two shafts at their ends, in order to transmit power and torque between two separate devices. The driving shaft usually transfers rotary motion from a power-generating device such as a motor or engine. While, the driven shaft is commonly the input of a transmission or a driven machine. In the industry, diffe...

When two elements with curved surfaces make contact with each other and are pressed together, contact stresses (also called Hertzian contact stresses) are developed within the contact areas. Theoretically, the contact is either a point (when at least one of the elements is a sphere) or a line (when at least one of the elements is a cylinder). High...

Universal joints (U-joints), also known as Cardan joints, are flexible couplings used to mate shafts, which are misaligned (at angles greater than 3º). This chapter presents a graphical method for designing U-joints.

V-belts are flexible elements that are used to transmit power and motion between shafts, which have a relatively long distance from each other. There are several types of V-belts, however, in this chapter we only discuss the normal (or standard) and narrow-section V-belts. This chapter deals with introducing our proposed graphical method for design...

Power screws are elements used for converting rotary motion to linear motion in machines. There are three forms of power screw threads: the square thread, the Acme thread, and the buttress thread. Power screws may also be either single-thread or double-thread or triple-thread. In this chapter, we only consider power screws with the Acme threads and...

Conical joint refers to a connection in which the shaft and hub are conical (in fact conical frustum) at the joint interface. The connected elements are pressed together by means of a bolt so that the torque and power can be transmitted by friction. This chapter deals with estimating the maximum torque that can be transmitted solely by a conical jo...

Rolling contact bearings are machine elements that are most commonly designed to support rotating shafts. One of the most important characteristics of rolling bearings to be specified is their bearing life. To determine the variable, the forces applied to the bearings should be calculated. This needs a good knowledge of statics and referring to man...

Estimating torque is necessary during design of rotating elements such as gears, pulleys, shafts, etc. In this chapter, we introduce a graphical method for easy estimation of torque.

Splines are a series of keys machined on outside of a shaft, with corresponding grooves machined on inside of hub of a power transmitting element. The same as keys, splines are used to provide a joint connection between the hub and the shaft for torque and power transmission. However, they are typically used in applications in which a high torque n...

Timing belts perform power and motion transmissions by means of teeth that are on the underside of the belt. Timing belts with different tooth profile shapes are available. In this chapter, we only discuss design of trapezoid and High Torque Drive (HTD) types. Design of timing belts includes determining the size of tooth pitch (in other words the b...

Flanged couplings are kind of rigid connections that are used to mate rotating shafts and transmit torque and power between them. They are applied when no relative motion should occur between the driving and driven shafts and an accurate shaft alignment is required. In the coupling, the flanges are connected to the ends of the shafts usually by key...

One of the most time-consuming calculations in designing machine elements is related to bolts and nuts. In this chapter, an attempt has been made to simplify the calculations of bolts and nuts using the graphical method. In the process of designing, first, a bolt with a specific diameter is chosen, based on the applied force. Then, it is checked to...

In some machines, hydraulic systems are used to transfer power and move some parts. In the hydraulic systems, a pump pressurizes a hydraulic fluid and sends it through hydraulic tubes to actuators (hydraulic motors and cylinders). There, the fluid’s pressure is applied to move the parts or hold them in their position. Then, the fluid is moved throu...

This paper presents a new mechanism (coupling) for power transmission between parallel shafts in more ranges. The mechanism consists of one drive shaft and one driven shaft, 3 S-shape transmitter links and 8 connecting links. The advantage of this mechanism is that the velocity ratio between input and output shafts remains constant at all movements...

This paper presents a new mechanism for transmission of power between parallel shafts for adjusting height of farm or construction machineries in more gages. The mechanism consists of a drive shaft, 3 quad transmitter links, 8 connecting links and driven shaft. Advantage of this mechanism is that the velocity ratio between input and output shafts r...