Please fill out the following form to submit a Request for Quote to any of the following companies listed on
This article covers everything you need to know about vibratory feeders.
Read further to learn more about:
A vibratory feeder is a conveying system designed to feed components or materials into an assembly process using controlled vibratory forces, gravity, and guiding mechanisms that position and orient materials. They have accumulation tracks of various widths, lengths, and depths, which are carefully chosen to fit the needs of the application, material, component, or part.
The goal of vibratory feeders is to move, feed, and convey bulk materials while using various forms of vibrations so that the materials are properly oriented for addition to a production line. They are a highly efficient method for increasing the speed of assembly operations and gently separating bulk materials. The guided movement produced by a vibratory feeder is dependent on horizontal and vertical accelerations that produce the exact amount of force needed to put materials in position.
The accumulation track of a vibratory feeder, which can be linear or gravity, slows feeder vibrations and assists in directional movement. Drive units can be piezoelectric, electromagnetic, or pneumatic motors that supply the vibrations, rotation, and necessary force.
The design of a vibratory feeder begins with a transporting trough or platform through which materials are moved by controlled linear vibrations that create the materials' jumping, hopping, and tossing motions. Depending on design features, travel speeds vary from a few feet per minute to over 100 feet (30 m) per minute, regulated by frequency, amplitude, and the slope angle.
The various vibratory feeders control material flow similarly to how orifices or valves control fluid flow. They can be set to feed bulk materials at a fixed rate with a structure that has soft springs to control vibrations and capacities, from a few pounds of bulk materials per hour to over several tons per hour.
One advantage of vibratory feeders is their ability to avoid bridging, which slows up processes and assemblies and prevents efficient material flow. The free flow in the throat of a vibratory feeder eliminates the possibility of bridging created by friction. The forces that provide smooth and even flow are classified as direct force and indirect force, with direct force sending force directly to the deck while indirect force is a resonant or natural frequency.
Recent vibratory feeder designs have enclosed feeders in a box shape and flanged inlets and outlets, making units dust or watertight to eliminate spillage and simplify installation. Some enclosed designs have a vibrating bin bottom activator combined with a vibratory feeder to control flow.
Bulk materials are dry solids in powder, granular, or particle form, with different sizes and densities randomly grouped to form a bulk. These materials have varied behaviors depending on temperature, humidity, time, and so on. They do not flow as easily and as predictable as liquids and gases. They can also easily degrade any equipment for conveying and handling by erosion and impingement.
In handling bulk materials, it is important to know their properties, as summarized below. These properties must be determined to properly design bulk handling equipment.
The general design of a vibratory feeder consists of a drive unit that generates the vibratory action and a deep channel, or trough, that contains the bulk material. The drive unit causes vibrations with both horizontal and vertical force components. The vibration causes a straight-line motion, provided the vibration is sinusoidal, and the force components are in-phase. Besides the drive unit and trough, a vibratory feeder is made up of the following parts:
Vibratory feeders and conveyors have operating frequencies that range from 200 to 3600 vibrations per minute with an amplitude of 1 to 40 mm. The vertical acceleration component is usually near gravitational acceleration (9.81 m/s2). This is enough to transport materials with a gentle shuffling motion producing minimal impact and noise. Because of this, the material moves across the trough by sliding action. The material does not actually leave the trough's surface when the pressure between the surface and the material is at a minimum. In applications where the material has to lift from the trough and then impact again as it falls, special considerations must be made to counter the impact force and the increased noise levels.
Vibratory feeders are distinct from other bulk material handling equipment because the material moves independently from the conveying medium. This contrasts with equipment such as conveyor belts and aprons, where the material is static relative to the conveying medium. This enables additional processes to be integrated while the material is in transit. Below are some processes that can be performed while transporting with vibratory feeders.
Besides the integration of additional processes, vibratory feeders are desired due to these reasons,
Low Headroom Requirement: Vibratory feeders are a solution to gravimetric feeding in installations with limited vertical clearance. Conveying using vibratory feeders is suited for the horizontal movement of bulk products.
Handling of Hot Materials Without Excessive Heating: Vibratory feeders can be tuned so a little lift is produced from the upward phases of the oscillation cycle. This allows some air to pass and cool the material while at the same time minimizing contact.
Handling Abrasive Materials: Tuning the vibratory feeder to minimize contact with the material reduces vibration. Also, vibratory feeders can be lined with abrasion-resistant materials.
Inherent Self-Cleaning Properties: Since the material is not static on the surface of the machine, the material does not easily adhere. There is no chance for the material to accumulate on the surface of the trough.
Adherence Strict Sanitation Requirements: Aside from its self-cleaning properties, the trough or pan of a vibratory feeder is a continuous surface. There are no cavities or holes where contaminants can accumulate. The pan can be made of stainless steel suited for food applications.
Water and Dust-Tight: Vibratory feeders can be designed with IP or NEMA-rated covers and sealing.
No Moving Parts Where Material Can Impinge and Interrupt Operation: The trough is a continuous channel with no hinges, joints, or deformable members, unlike belt and apron conveyors. Because of these benefits, vibratory feeders are widely used in mining, smelting, metal casting, recycling, glass batch processing, furnace charging, wood processing, food processing, pharmaceuticals, and packaging.
Vibratory feeders can be classified according to their drive unit, method of applying vibration to the trough, and generated reaction to the supporting structures. In selecting a vibratory feeder, it is important to know the distinction between these categories. For example, it is not enough to specify only brute force vibratory feeders. Brute force feeders are available with electromagnetic or electromechanical drive units. This chapter tackles the working principle of each type and their recommended applications.
Below are vibratory feeders classified according to their drive unit:
These feeders create vibration by rotating eccentric weights using electric motors. They are also referred to as eccentric-mass mechanical feeders. A simple design consists of a single rotating eccentric mass. However, the more common is the use of two counter-rotating masses. The axes of rotation of these two masses lie within the same plane, and their rotation is synchronized to produce the right oscillation.
Electromagnetic feeders operate using the cyclic energization of one or more electromagnets. In comparison with electromechanical drives, electromagnetic drive units contain lesser moving parts. The trough is caused to vibrate using the magnetic force impulses supplied by the electromagnet. In terms of cost, electromagnetic feeders are cheaper for low-volume applications. This is true at rates less than 5 tons per hour.
These types of feeders operate using pneumatic or hydraulic oscillating pistons. The main advantage of using these types is their suitability for hazardous areas. The motors for driving the pumping units can be located in remote areas. This eliminates the need for expensive explosion-proof specifications.
Direct or positive mechanical vibratory feeders use a crank and connecting rod that generate oscillation with a low frequency and high amplitude. Positive conveyors are rarely used due to the high vibration transmitted to the supporting structures. A way to counter the high vibration transmitted is to use a counterweight or counter-vibrating double troughs.
Next are the types of vibratory feeders according to the method of applying vibration to the trough. They differ in the configurations of their springs and the frequency and amplitude of their drive unit.
This type of feeder is called single-mass systems because the vibratory drive is directly connected to the trough assembly. They are generally used for heavy-duty applications. The drive system can also be electromagnetic, but the electromechanical drive is mostly used. Brute force feeders create oscillating forces by rotating a heavy centrifugal counterweight.
Brute force feeders have the simplest design among the vibratory feeders. However, they have limited feed rate regulation and range since they are designed as constant rate feeders. The feed rate can be adjusted by changing the slope of the trough, opening, amount of counterweight, and length of stroke. Variable speed drives are rarely installed since the trough stroke is slightly independent of the operating speed of the motor. Tuning the motor speed is not necessary for brute force feeders.
Centrifugal feeders, also known as rotary feeders, consist of a spinning bowl that moves parts towards the outside of the bowl. They have a conical centrally driven rotor surrounded by the bowl walls. As the feeder spins, the rotary force separates parts and components. The revolving parts, moving at high speed, are pulled and pushed to the outside circumference of the bowl.
The uses for centrifugal feeder systems include food processing, the pharmaceutical industry, and medical suppliers, which are industries that have small, unusually shaped components that require rapid handling. Centrifugal bowl feeders sort and properly orient components at a rate of 3000 per minute regardless of the size and shape of the components. They are a cost-effective processing method with a simple design, are exceptionally reliable, and have low maintenance.
Natural frequency feeders, also known as tuned or resonant feeders, use two or more spring-connected masses. The most common is the two-mass, spring-connected vibratory system. One mass is for the trough, while the other is for the reaction or excitation mass. The natural frequency feeder takes advantage of the natural magnification of the oscillations, which occurs when the system operates at a speed near its natural frequency or resonance condition. Because of this, a relatively small force is required to generate the necessary vibratory forces. The vibratory force can be generated by rotating eccentric weights or electromagnets.
The main design factor that needs to be considered is not the weight of the material or load but the damping capacity of the bulk. The damping effect is the result of the energy absorption of the material. Granular and powdered materials tend to dissipate energy through intergranular friction and deformation when vibrated.
Vibratory feeders are also classified according to their reactions to their foundations and supporting structures. Selecting which type depends on the rigidity and allowable stresses of the structure.
These feeders have oscillating forces that subject the supporting structures to reversing load conditions. A reversing load condition means continuous and alternating tensile and compressive forces while the mean stress is zero. Though the supporting structure can easily carry the static load of the feeder, it becomes easily fatigued during operation. Unbalanced vibratory feeders can only be installed on structures that have very large allowable deflections compared to the amplitude of the vibrations. Moreover, the structure must have a natural frequency that greatly exceeds the operating frequency of the feeder.
A balanced vibratory feeder is equipped with a dynamic balancing system composed of counterbalancing weights installed on the conveyor base. Other designs employ secondary weights attached to the reactor springs. These types of feeders are designed to reduce the unbalanced reaction force transmitted to the supporting structure. This is achieved by vibrating the secondary weights 180° out of phase with the oscillation of the trough. Balanced vibratory feeders are recommended for installation on structures with questionable rigidity.
Horizontal motion conveyors, also known as horizontal differential conveyors, differential motion conveyors, or differential conveyors, use a two-cycle slow advance, quick return motion to slowly move free-flowing bulk materials horizontally. The conveying surface is an open pan or closed conduit with seamless one-piece construction that moves slowly forward and backward. During forward movement, components remain at quiet rest. On the return cycle, the open pan or closed conduit moves swiftly and rapidly backward, depositing the components.
A horizontal motion conveyor's forward and backward motion is continually repeated to smoothly convey materials at 40 feet (12 m) per minute over distances as long as 200 feet (61 m). They have no moving parts other than the drive unit, which reduces safety risks, simplifies cleaning, and decreases maintenance. The smooth, even motion of horizontal motion conveyors is ideal for fragile materials that need to be handled carefully.
Horizontal motion conveyors can move components backward or forward one direction at a time. They can be configured to work on slight inclines or declines for flat rectangular or square parts. If necessary, horizontal motion conveyors can be set up to deliver parts in their midsection. Components move along the open pan or conduit without being subjected to vertical acceleration bouncing action.
The capacity of the vibrating feeder depends on the width of the trough, depth of material flow, bulk density of the material, and the linear feed rate. This is expressed by the formula,
C = WdR / 4800
Where C is the capacity in tons per hour (metric tons per hour), W is the trough width in inches (millimeter), d is the depth of material in inches (millimeter), γ is the bulk density in pounds per cubic feet (grams per cubic centimeter), and R is the linear feed rate in feet per minute (meter per minute). For metric units, change the 4,800 constant to 16,700.
Usually, the required capacity is already given by the rate requirement of upstream or downstream processes. From the required capacity, combinations of trough width and linear feed rate can be obtained along with the bulk density of the material and expected feed depth. Manufacturers typically provide charts, tables, and graphs describing the feeder's characteristics.
Feeder troughs are usually made from mild steel, grade 304 stainless steel, and abrasion-resistant alloys. Other constructions feature ordinary steels lined with replaceable materials such as rubber, plastic, or ceramics. Troughs are formed into different shapes depending on the type and properties of the materials and the integrated processes. Common trough shapes and features are:
Vibratory bowl feeders have troughs wound helically and use vibrations to toss and shuffle materials along the slightly slanted surface of the helical trough. The tossing and shuffling actions position parts with asymmetrical shapes to be oriented as they move through the bowl feeder.
The benefits of a vibratory bowl feeder include conveying parts and positioning them properly. Troughs have specific profiles for accepting materials in the correct orientation. Screening devices attached to the bowl remove parts that are not positioned or oriented properly. Vibratory bowl feeders are used in assembly and packaging lines in the electronics, automotive, and pharmaceutical industries.
With high quality products and considerate service, we will work together with you to enhance your business and improve the efficiency. Please don't hesitate to contact us to get more details of vibrating grizzly feeders.