Vibrator (mechanical)
Encyclopedia
A vibrator is a mechanical device to generate vibration
s. The vibration is often generated by an electric motor
with an unbalanced
mass
on its driveshaft
.
There are many different types of vibrator. Some are components of larger products such as cellphones, pager
s, and vibrator sex toys
.
s and pager
s vibrate, the vibrating alert
is produced by a small component that is built into the phone or pager. Many older, non-electronic buzzers and doorbells contain a component that vibrates for the purpose of producing a sound. Tattoo machines and some types of electric engraving tools contain a mechanism that vibrates a needle or cutting tool.
Vibratory feeders and vibrating hopper
s are used extensively in the food, pharmaceutical, and chemical industries to move and position bulk material or small component parts. The application of vibration working with the force of gravity can often move materials through a process more effectively than other methods. Vibration is often used to position small components so that they can be gripped mechanically by automated equipment as required for assembly etc.
Vibrating screens are used to separate bulk materials in a mixture of different sized particles. For example sand, gravel, river rock and crushed rock, and other aggregates
are often separated by size using vibrating screens.
Vibrating compactor
s are used for soil
compaction especially in foundations for roads, railways, and buildings.
Concrete
vibrators consolidate freshly poured concrete so that trapped air and excess water are released and the concrete settles firmly in place in the formwork. Improper consolidation of concrete can cause product defects, compromise the concrete strength, and produce surface blemishes such as bug holes and honeycombing. An internal concrete vibrator is a steel cylinder about the size of the handle of a baseball bat, with a hose or electrical cord attached to one end. The vibrator head is immersed in the wet concrete.
External concrete vibrators attach, via a bracket or clamp system, to the concrete forms. There are a wide variety of external concrete vibrators available and some vibrator manufacturers have bracket or clamp systems designed to fit the major brands of concrete forms. External concrete vibrators are available in hydraulic, pneumatic or electric power.
Vibrating tables or shake tables are sometimes used to test products to determine or demonstrate their ability to withstand vibration. Testing of this type is commonly done in the automotive, aerospace, and defense industries. These machines are capable of producing three different types of vibration profile sine
sweep, random vibration, and synthesized shock
. In all three of these applications, the part under test will typically be instrumented with one or more accelerometers to measure component response to the vibration input. A sine sweep vibration profile typically starts vibrating at low frequency and increases in frequency at a set rate (measured in hertz
per second or hertz per minute). The vibratory amplitude as measured in gs
may increase or decrease as well. A sine sweep will find resonant
frequencies in the part. A random vibration profile will excite different frequencies along a spectrum at different times. Significant calculation goes into making sure that all frequencies get excited to within an acceptable tolerance band. A random vibration test suite may range anywhere from 30 seconds up to several hours. It is intended to synthesize the effect of, for example, a car driving over rough terrain or a rocket taking off. A synthesized shock pulse is a short duration high level vibration calculated as a sum of many half-sine waves covering a range of frequencies. It is intended to simulate the effects of an impact or explosion. A shock pulse test typically lasts less than a second. Vibrating tables can also be used in the packaging process in material handling industries to shake or settle a container so it can hold more product.
Oscillation
Oscillation is the repetitive variation, typically in time, of some measure about a central value or between two or more different states. Familiar examples include a swinging pendulum and AC power. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes...
s. The vibration is often generated by an electric motor
Electric motor
An electric motor converts electrical energy into mechanical energy.Most electric motors operate through the interaction of magnetic fields and current-carrying conductors to generate force...
with an unbalanced
Mechanical equilibrium
A standard definition of static equilibrium is:This is a strict definition, and often the term "static equilibrium" is used in a more relaxed manner interchangeably with "mechanical equilibrium", as defined next....
mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
on its driveshaft
Driveshaft
A drive shaft, driveshaft, driving shaft, propeller shaft, or Cardan shaft is a mechanical component for transmitting torque and rotation, usually used to connect other components of a drive train that cannot be connected directly because of distance or the need to allow for relative movement...
.
There are many different types of vibrator. Some are components of larger products such as cellphones, pager
Pager
A pager is a simple personal telecommunications device for short messages. A one-way numeric pager can only receive a message consisting of a few digits, typically a phone number that the user is then requested to call...
s, and vibrator sex toys
Vibrator (sex toy)
Vibrators are devices for the body and skin, to stimulate the nerves for a relaxing and pleasurable feeling. Some vibrators are designed to ergonomically stimulate erogenous zones for erotic stimulation.-History:...
.
Vibrators as components
When mobile phoneMobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
s and pager
Pager
A pager is a simple personal telecommunications device for short messages. A one-way numeric pager can only receive a message consisting of a few digits, typically a phone number that the user is then requested to call...
s vibrate, the vibrating alert
Vibrating alert
A vibrating alert is a feature of communications devices to notify the user of an incoming connection. It is particularly common on mobile phones and pagers and usually supplements the ring tone....
is produced by a small component that is built into the phone or pager. Many older, non-electronic buzzers and doorbells contain a component that vibrates for the purpose of producing a sound. Tattoo machines and some types of electric engraving tools contain a mechanism that vibrates a needle or cutting tool.
Industrial vibrators
Vibrators are used in many different industrial applications both as components and as individual pieces of equipment.Vibratory feeders and vibrating hopper
Hopper
Hopper may refer to:-Mechanical parts:* A general term for a chute with additional width and depth for temporary storage* Hopper , a large container used for dust collection* Part of a combine harvester...
s are used extensively in the food, pharmaceutical, and chemical industries to move and position bulk material or small component parts. The application of vibration working with the force of gravity can often move materials through a process more effectively than other methods. Vibration is often used to position small components so that they can be gripped mechanically by automated equipment as required for assembly etc.
Vibrating screens are used to separate bulk materials in a mixture of different sized particles. For example sand, gravel, river rock and crushed rock, and other aggregates
Construction Aggregate
Construction aggregate, or simply "aggregate", is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined material in the world...
are often separated by size using vibrating screens.
Vibrating compactor
Compactor
A compactor is a machine or mechanism used to reduce the size of waste material or soil through compaction. A trash compactor is often used by homes and businesses to reduce the volume of trash....
s are used for soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
compaction especially in foundations for roads, railways, and buildings.
Concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
vibrators consolidate freshly poured concrete so that trapped air and excess water are released and the concrete settles firmly in place in the formwork. Improper consolidation of concrete can cause product defects, compromise the concrete strength, and produce surface blemishes such as bug holes and honeycombing. An internal concrete vibrator is a steel cylinder about the size of the handle of a baseball bat, with a hose or electrical cord attached to one end. The vibrator head is immersed in the wet concrete.
External concrete vibrators attach, via a bracket or clamp system, to the concrete forms. There are a wide variety of external concrete vibrators available and some vibrator manufacturers have bracket or clamp systems designed to fit the major brands of concrete forms. External concrete vibrators are available in hydraulic, pneumatic or electric power.
Vibrating tables or shake tables are sometimes used to test products to determine or demonstrate their ability to withstand vibration. Testing of this type is commonly done in the automotive, aerospace, and defense industries. These machines are capable of producing three different types of vibration profile sine
Sine
In mathematics, the sine function is a function of an angle. In a right triangle, sine gives the ratio of the length of the side opposite to an angle to the length of the hypotenuse.Sine is usually listed first amongst the trigonometric functions....
sweep, random vibration, and synthesized shock
Shock (mechanics)
A mechanical or physical shock is a sudden acceleration or deceleration caused, for example, by impact, drop, kick, earthquake, or explosion. Shock is a transient physical excitation....
. In all three of these applications, the part under test will typically be instrumented with one or more accelerometers to measure component response to the vibration input. A sine sweep vibration profile typically starts vibrating at low frequency and increases in frequency at a set rate (measured in hertz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
per second or hertz per minute). The vibratory amplitude as measured in gs
G-force
The g-force associated with an object is its acceleration relative to free-fall. This acceleration experienced by an object is due to the vector sum of non-gravitational forces acting on an object free to move. The accelerations that are not produced by gravity are termed proper accelerations, and...
may increase or decrease as well. A sine sweep will find resonant
Resonance
In physics, resonance is the tendency of a system to oscillate at a greater amplitude at some frequencies than at others. These are known as the system's resonant frequencies...
frequencies in the part. A random vibration profile will excite different frequencies along a spectrum at different times. Significant calculation goes into making sure that all frequencies get excited to within an acceptable tolerance band. A random vibration test suite may range anywhere from 30 seconds up to several hours. It is intended to synthesize the effect of, for example, a car driving over rough terrain or a rocket taking off. A synthesized shock pulse is a short duration high level vibration calculated as a sum of many half-sine waves covering a range of frequencies. It is intended to simulate the effects of an impact or explosion. A shock pulse test typically lasts less than a second. Vibrating tables can also be used in the packaging process in material handling industries to shake or settle a container so it can hold more product.