A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment or end movement or both. In a more general context, a coupling can also be a mechanical device that serves to connect the ends of adjacent parts or objects. Couplings do not normally allow disconnection of shafts during operation, however there are torque-limiting couplings which can slip or disconnect when some torque limit is exceeded. Selection, installation and maintenance of couplings can lead to reduced maintenance time and maintenance cost.
Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between parts of an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit.
Standard diving dress, also known as hard-hat or copper hat equipment, deep sea diving suit or heavy gear, is a type of diving suit that was formerly used for all relatively deep underwater work that required more than breath-hold duration, which included marine salvage, civil engineering, pearl shell diving and other commercial diving work, and similar naval diving applications. Standard diving dress has largely been superseded by lighter and more comfortable equipment.
A turnbuckle, stretching screw or bottlescrew is a device for adjusting the tension or length of ropes, cables, tie rods, and other tensioning systems. It normally consists of two threaded eye bolts, one screwed into each end of a small metal frame, one with a conventional right-hand thread and the other with a left-hand thread. The tension can be adjusted by rotating the frame, which causes both eye bolts to be screwed in or out simultaneously, without twisting the eye bolts or attached cables.
In mechanical engineering, an eccentric is a circular disk solidly fixed to a rotating axle with its centre offset from that of the axle.
A fastener or fastening is a hardware device that mechanically joins or affixes two or more objects together. In general, fasteners are used to create non-permanent joints; that is, joints that can be removed or dismantled without damaging the joining components. Steel fasteners are usually made of stainless steel, carbon steel, or alloy steel.
A bolted joint is one of the most common elements in construction and machine design. It consists of a male threaded fastener that captures and joins other parts, secured with a matching female screw thread. There are two main types of bolted joint designs: tension joints and shear joints.
A mandrel, mandril, or arbor is a tapered tool against which material can be forged, pressed, stretched or shaped, or a flanged or tapered or threaded bar that grips a workpiece to be machined in a lathe. A flanged mandrel is a parallel bar of a specific diameter with an integral flange towards one end, and threaded at the opposite end. Work is gripped between the flange and a nut on the thread. A tapered mandrel has a taper of approximately 0.005 inches per foot and is designed to hold work by being driven into an accurate hole on the work, gripping the work by friction. A threaded mandrel may have a male or female thread, and work which has an opposing thread is screwed onto the mandrel.
A collet is a segmented sleeve, band or collar. One of the two radial surfaces of a collet is usually tapered and the other is cylindrical. The term collet commonly refers to a type of chuck that uses collets to hold either a workpiece or a tool, but collets have other mechanical applications.
A chuck is a specialized type of clamp used to hold an object with radial symmetry, especially a cylinder. In a drill, a mill and a transmission, a chuck holds the rotating tool; in a lathe, it holds the rotating workpiece.
A linear actuator is an actuator that creates linear motion, in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor.
A hydraulic cylinder is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment, manufacturing machinery, elevators, and civil engineering. A hydraulic cylinder is a hydraulic actuator that provides linear motion when hydraulic energy is converted into mechanical movement. It can be likened to a muscle in that, when the hydraulic system of a machine is activated, the cylinder is responsible for providing the motion.
A vacuum flange is a flange at the end of a tube used to connect vacuum chambers, tubing and vacuum pumps to each other. Vacuum flanges are used for scientific and industrial applications to allow various pieces of equipment to interact via physical connections and for vacuum maintenance, monitoring, and manipulation from outside a vacuum's chamber. Several flange standards exist with differences in ultimate attainable pressure, size, and ease of attachment.
A sex bolt is a type of fastener comprising a mated pair of screw and post, which are a machine screw and a nut that is barrel-shaped. The nut has a flange and a protruding boss that is internally threaded. The bolt sits within the components being fastened, and the flange provides the bearing surface.
A fitting or adapter is used in pipe systems to connect sections of pipe or tube, adapt to different sizes or shapes, and for other purposes such as regulating fluid flow. These fittings are used in plumbing to manipulate the conveyance of fluids such as water for potatory, irrigational, sanitary, and refrigerative purposes, gas, petroleum, liquid waste, or any other liquid or gaseous substances required in domestic or commercial environments, within a system of pipes or tubes, connected by various methods, as dictated by the material of which these are made, the material being conveyed, and the particular environmental context in which they will be used, such as soldering, mortaring, caulking, plastic welding, welding, friction fittings, threaded fittings, and compression fittings.
Multi-jackbolt tensioners (MJT) are an alternative to traditional bolted joints. Rather than needing to tighten one large bolt, MJTs use several smaller jackbolts to significantly reduce the torque required to attain a certain preload. MJTs range in thread sizes from 3⁄4 in (19 mm) to 32 in (810 mm) and can achieve 20 million pounds-force or more. MJTs only require hand-held tools, such as torque wrenches or air/electric impacts, for loading and unloading bolted joints.
A screw is an externally helical threaded fastener capable of being tightened or released by a twisting force (torque) to the head. The most common uses of screws are to hold objects together and there are many forms for a variety of materials. Screws might be inserted into holes in assembled parts or a screw may form its own thread. The difference between a screw and a bolt is that the latter is designed to be tightened or released by torquing a nut.
A mechanical joint is a section of a machine which is used to connect one or more mechanical parts to another. Mechanical joints may be temporary or permanent; most types are designed to be disassembled. Most mechanical joints are designed to allow relative movement of these mechanical parts of the machine in one degree of freedom, and restrict movement in one or more others.
A scuba cylinder valve or pillar valve is a high pressure manually operated screw-down shut off valve fitted to the neck of a scuba cylinder to control breathing gas flow to and from the pressure vessel and to provide a connection with the scuba regulator or filling whip. Cylinder valves are usually machined from brass and finished with a protective and decorative layer of chrome plating. A metal or plastic dip tube or valve snorkel screwed into the bottom of the valve extends into the cylinder to reduce the risk of liquid or particulate contaminants in the cylinder getting into the gas passages when the cylinder is inverted, and blocking or jamming the regulator.
