Mechanical Principles Part 04 | Nautilus Gear | Universal joint | Schmidt coupling | Radial engine

Mechanical Principles Part 04 | Nautilus Gear | Universal joint | Schmidt coupling | Radial engine



0:00 Intro
0:01 Nautilus Gear
0:07 Universal joint
0:09 Schmidt coupling
0:13 CV joint
0:17 Spiral tooth gear
0:24 Reuleaux indexing gear
0:33 Multiple iris
0:44 Radial engine
0:56 Intermittent rotation
1:05 Multiple geneva
1:11 Speed governor
1:20 Sun and Planet gear
1:28 Crown wheel
1:33 Double cardan joint
1:39 Indexing Table

A universal joint (also called a universal coupling or U-joint) is a joint or coupling connecting rigid shafts whose axes are inclined to each other. It is commonly used in shafts that transmit rotary motion. It consists of a pair of hinges located close together, oriented at 90° to each other, connected by a cross shaft. The universal joint is not a constant-velocity joint.


U-joints are also sometimes called by various eponymous names, as follows:

Cardan joint, after Gerolamo Cardano, a polymath of the 16th century who contributed to knowledge of various clever mechanisms, including gimbals
Hooke joint or Hooke's joint, after Robert Hooke, a polymath of the 17th century who contributed to knowledge of various clever mechanisms
Spicer joint, after Clarence W. Spicer and the Spicer Manufacturing Company, who manufactured U joints
Hardy Spicer joint, after the Hardy Spicer brand, a successor to the Spicer brand
A Schmidt coupling is a type of coupling designed to accommodate large radial displacement between two shafts. Consisting of an arrangement of links and discs—three discs rotating in unison, interconnected in series by three or more links between each pair of discs—a Schmidt coupling can adapt to very wide variations in radial displacement while running under load. Couplings can be made to allow radial displacement greater than twice the radius of the discs.

A constant-velocity joint (also called a CV joint) is a mechanical coupling which allows the shafts to rotate freely (without an appreciable increase in friction or backlash) and compensates for the angle between the two shafts, within a certain range, to maintain the same velocity.

A common use of CV joints is in front-wheel drive vehicles, where they are used to transfer the engine's power to the wheels, even as the angle of the driveshaft varies due to the operation of the suspension.

The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is called a "star engine" in some other languages.

The radial configuration was commonly used for aircraft engines before gas turbine engines became predominant.

A governor, or speed limiter or controller, is a device used to measure and regulate the speed of a machine, such as an engine.

A classic example is the centrifugal governor, also known as the Watt or fly-ball governor on a reciprocating steam engine, which uses the effect of inertial force on rotating weights driven by the machine output shaft to regulate its speed by altering the input flow of steam.

The sun and planet gear is a method of converting reciprocating motion to rotary motion and was used in the first rotative beam engines.

It was invented by the Scottish engineer William Murdoch, an employee of Boulton and Watt, but was patented by James Watt in October 1781. [1] It was invented to bypass the patent on the crank, already held by James Pickard.[2] It played an important part in the development of devices for rotation in the Industrial Revolution.