What is a gyroscope?

Question

What is it and how does it work?

Answer 1

A gyroscope is a device which demonstrates the principle of conservation of angular momentum, in physics this is also known as gyroscopic inertia or rigidity in space.

Within mechanical combinations or devices constituting portions of machines, a conventional gyroscope is a mechanism comprising a rotor journaled to spin about one axis, the journals of the rotor being mounted in an inner gimbal or ring, the inner gimbal being journaled for oscillation in an outer gimbal which in turn is journaled for oscillation relative to a support. The outer gimbal or ring is mounted so as to pivot about an axis in its own plane determined by the support. The outer gimbal possesses one degree of rotational freedom and its axis possesses none. The inner gimbal is mounted in the outer gimbal so as to pivot about an axis in its own plane which axis is always normal to the pivotal axis of the outer gimbal.

The axle of the spinning wheel defines the spin axis. The inner gimbal possesses two degrees of rotational freedom and its axis possesses one. The rotor is journaled to spin about an axis which is always normal to the axis of the inner gimbal. Hence the rotor possesses three degrees of rotational freedom and its axis possesses two. The wheel responds to a force applied about the input axis by a reaction force about the output axis. The 3 axes are perpendicular, and this cross-axis response is the simple essence of the gyroscopic effect.

A gyroscope flywheel will roll or resist about the output axis depending upon whether the output gimbals are of a free- or fixed- configuration. Examples of some free-output-gimbal devices would be the attitude reference gyroscopes used to sense or measure the pitch, roll and yaw attitude angles in a spacecraft or airplane, and the front wheel of a motorcycle. Countersteering is how motorcycles turn corners using the gyroscopic roll reaction of the spinning front wheel.

The center of gravity of the rotor can be in a fixed position. The rotor simultaneously spins about one axis and is capable of oscillating about the two other axes, and thus, except for its inherent resistance due to rotor spin, it is free to turn in any direction about the fixed point. Some gyroscopes have mechanical equivalents substituted for one or more of the elements, e.g., the spinning rotor may be suspended in a fluid, instead of being pivotally mounted in gimbals. A control moment gyroscope (CMG) is an example of a fixed-output-gimbal device that is used on spacecraft to hold or maintain a desired attitude angle or pointing direction using the gyroscopic resistance force.

In some special cases, the outer gimbal (or its equivalent) may be omitted so that the rotor has only two degrees of freedom. In other cases, the center of gravity of the rotor may be offset from the axis of oscillation, and thus the center of gravity of the rotor and the center of suspension of the rotor may not coincide.

Answer 2

A device consisting of a spinning mass, typically a disk or wheel, mounted on a base so that its axis can turn freely in one or more directions and thereby maintain its orientation regardless of any movement of the base.

When spinning, the gyroscope has special properties. Many spinning objects exhibit some of these properties; the rotation of the earth about its axis gives it the properties of a huge gyroscope. Once a gyroscope starts to spin, it will resist changes in the orientation of its spin axis. For example, a spinning top resists toppling over, thus keeping its spin axis vertical. If a torque, or twisting force, is applied to the spin axis, the axis will not turn in the direction of the torque, but will instead move in a direction perpendicular to it. This motion is called precession. The wobbling motion of a spinning top is a simple example of precession. The torque that causes the wobbling is the weight of the top acting about its tapering point. The modern gyroscope was developed in the first half of the 19th cent. by the French physicist Jean B. L. Foucault, and its first notable use was in a visual demonstration of the earth's rotation. In the second half of the 19th cent., with the invention of the electrically driven rotor, its uses multiplied. It became possible to rotate the gyroscope's wheel at desired speeds without interfering with the precession. Large gyroscopes are used in ship stabilizers to counteract rolling. The gyroscope is the nucleus of most automatic steering systems, such as those used in airplanes, missiles, and torpedoes. It is also used in the gyrocompass, a directional instrument used on ships. Unaffected by magnetic variations, its spinning axis, when brought in line with the north-south axis of the earth, provides an accurate line of reference for navigation.

Answer 3

A gyroscope is a nifty device. It works on the principle of a spinning top. When it's spinning it wants to stay in one orientation. If you could keep one spinning long enough it would change positions as the Earth rotated.
It is the gyroscopic effect of the spinning wheels on a bicycle which help it to stay up. Gyroscopes are used in all kinds of devises that we take for granted.

Answer 4

Think of a rear Bicycle wheel, turn it upside down and get it spinning as fast as you can. This is a Gyroscope. Only not as well Balanced. When it spins it will want to hold its position and not want to turn. This why Bicycles and Motorcycles can be easily ridden without holding the Handle Bars. The Wheels spinning help to keep them wanting to stay up!
See Pics below link.

Answer 5

You have correct answers already for general application. However since you were in a museum, I'll add an historic application. They were also used to determine lead angle for early gun-sites. The cross-hairs were etched in a mirror attached to a gyro. A light shone on the mirror reflected the cross-hairs onto the windscreen. The gyro would lag the aircraft turn the amount of lead required to hit the target. In an estimated lead turn the pilot put the pippler on the target to establish the correct lead angle. This was an early form of kinematic, analog, ballistics. Initially gyro stabilization, precession, was influenced by an electrical current in stabilizer fields. Range rings enabled the current to be adjusted based on estimated range. Later, range current was provided by 'Range Only' Radar. These were the gun-sites that gave the US an advantage over Migs in the Korean War. Could not have been achieved without Gyros. It's been more than forty years since I worked on these systems, but I think I have the basics right.

Answer 6

A device that wants to stay in one orientation.


Used as a reference.

Any wheel spinning fast is a gyroscope.

Answer 7

segway baby!!!