Provisional Utility Patent Application - Specification

Title

Vibratory Apparatus

Inventor

Spenser Saling

Field of the invention

The present invention relates to vibratory equipment. Vibratory equipment may be used for, but is not limited to separating, screening, freeing-up, breaking-up, breaking-down, and distributing material.

Key Terms & Definitions

The following terms will be used throughout this document and are defined as follows:

Process Material: The material that a piece of vibratory equipment is meant to process. This includes, but is not limited to recyclables, waste, rock, ore, wood, compost, metal scrap, components, parts, and shredded material.

Auxiliary Components: Components outside the scope of the present invention that may or may not be used in combination with the present invention to create a piece of vibratory equipment.

Material Interface: An auxiliary component in a vibratory assembly which is meant to interface with the process material. This includes, but is not limited to separation pans, screens, distribution pans, hoppers, and fluidized beds.

Vibratory Exciter: An auxiliary component in a vibratory assembly which supplies an oscillating force to the system. This includes, but is not limited to vibratory motors. This could also be replaced by any form of weight in a passive vibratory system.

Base Structure: An auxiliary component in a vibratory assembly upon which a piece of vibratory equipment is mounted.

Absorption Mount: An auxiliary component used to tether vibratory equipment to a base structure. This includes, but is not limited to coil springs, leaf springs, cantilevered springs, and rubber.

Single-Mass: A type of vibratory equipment where the vibratory exciter is rigidly mounted to the material interface. Illustrated in Figure 1.

Two-Mass: A type of vibratory equipment where the vibratory exciter is mounted to the material interface through a flexible spring connection. Illustrated in Figure 2.

Stroke: The maximum amplitude or displacement of the Material Interface from its center position during vibration.

Background (Problem)

The most simple kind of vibratory equipment is single-mass (Figure 1.1). In single-mass vibratory equipment, the vibratory exciter is rigidly mounted to the vibratory interface. The vibratory interface is mounted to its base structure directly by means of an absorption mount. Therefore, any vibration of the vibratory interface is imparted directly to the base structure through the absorption mount. Single-mass vibratory equipment requires a base structure that can absorb and resist this vibration. This limits the possible stroke of the vibration, frequency of the vibration, mass of the vibratory interface, and height of the base structure. Single-mass designs are also inefficient because much of the vibrational energy is absorbed by the absorption mounts and base structure.

Figure 1.1: Existing Vibratory Equipment - Single-Mass

A simplified spring-mass diagram of single-mass vibratory equipment, where the vibratory exciter is rigidly connected to the material interface. Intended vibration is along the z-axis.

A more complex kind of vibratory equipment is two-mass (Figure 1.2). Two-mass vibratory equipment still mounts the material interface directly to the base structure through an absorption mount. However, the vibratory exciter is mounted to the material interface through a flexible spring. The two-mass design allows the majority of the material interface’s momentum to be offset by that of the vibratory exciter during vibration. This produces a vibration that is more efficient and does not transmit as much energy into the base. Two-mass vibratory equipment has reduced limitations compared to single-mass. Two-mass vibratory equipment is capable of achieving higher stroke, higher frequencies, and/or higher material interface mass. Since the two-mass design offsets the momentum of the material interface with the vibratory exciter, they allow for lighter/taller base structures. However, this design involves complex spring assemblies, increased cost, larger footprint, and higher manufacturing time.

Figure 1.2: Existing Vibratory Equipment - Two-Mass

A simplified spring-mass diagram of two-mass vibratory equipment, where the vibratory exciter is connected to the material interface by means of a spring. Intended vibration is along the z-axis.

Summary of the Invention (Solution)

The present invention seeks to allow for the creation of vibratory equipment with reduced limitations compared to what is presently available on the market. The present invention does this by utilizing an improved spring system, as shown in Figures 2.1 & 2.2. This improved spring system allows for isolated mounting point(s) that transmit reduced vibration into the base structure. This improved spring system will also allow for higher stroke, higher vibration frequency, and a higher material interface mass while transmitting less vibration forces into the base structure. Additionally, the preferred configuration of the present invention (Figure 3.1) allows for the spring system and mount to be created with little complexity and few manufacturing steps. This reduces complexity, cost, footprint, and manufacturing time compared to the two-mass design.

Figure 2.1: Present Invention Spring-Mass Diagram

A simplified spring-mass diagram of the present invention. Intended vibration is along the z-axis.

Figure 2.2: Present Invention Spring-Mass Diagram With Additional Annotations

A simplified spring-mass diagram of the present invention with additional annotations. Intended vibration is along the z-axis.

Detailed Description of the Invention

The present invention encompasses the following from Figure 2.2: Spring 1, Spring 2, and the Isolated mount point. There are a variety of ways to accomplish this. Spring 1 and Spring 2 could be, but are not limited to leaf springs, cantilevered springs and coil springs. The springs could be attached to the isolated mount point by a variety of means that include, but are not limited to fasteners, clips, welds, adhesives, and wire. The springs and the mount point could be fabricated from a variety of materials including but not limited to metals, plastics, composites, wood, steel, aluminum, and titanium.

The present invention, shown in Figure 2.2, will perform best when the mass of the Material Interface equals that of the Vibratory Exciter (m1 = m2), and when the spring constant of Spring 1 is equal that of Spring 2 (k1 = k2). If those conditions are met, then the natural frequency of the Material Interface and Spring 1 will equal the natural frequency of the Vibratory Exciter and Spring 2. Additionally, if m1 = m2 and k1 = k2, the acceleration forces created by the moving masses during vibration will be equal and opposite, cancelling each other. The natural frequency of each of these subsystems can be approximated as follows:

Equation 1: 

Note that it is possible to use the present invention in a configuration where m1 ≠ m2 or k1 ≠ k2. In this case, the system will still run best if the natural frequencies are identical, or nearly identical as shown in Equation 1. However, in this case, the forces created by m1 and m2 during vibration will not be equal and opposite. This residual force will need to be transferred to the base structure. It is also possible to use the present invention in a design where the natural frequencies of the two mass-spring systems shown in Equation 1 do not match. For example, a user might design a system so that the material interface (m1/k1) has a lower mass (and therefore a higher natural frequency) than the vibratory exciter (m2/k2). Then during operation, when the material interface (m1) is loaded with process material, its effective mass will increase, lowering the natural frequency to match that of the vibratory exciter (m2).

The selected vibratory exciter must be able to excite the system at this same natural frequency. In this way, the vibratory exciter and material interface will oscillate opposite each other. Theoretically, the isolated mount point should experience little to no motion, except when energy is being transferred from the vibratory exciter to the material interface. The amount of motion and force imparted to the base structure by the isolated mount point should be low compared to other vibratory equipment designs as shown in Figure 1.1 and Figure 1.2.

During operation, as the material interface is loaded with process material, the system’s natural frequency will change due to the added mass. The vibratory exciter may need to adjust its frequency to deal with this change. The vibratory exciter may or may not incorporate an automated system to control frequency. Such a control system is outside the scope of the present invention.

Another challenge to implementing the spring system shown in Figure 2.2 is to restrict vibration to the z-axis. To accomplish this, modes of vibration out of line with the z-axis must be minimized. Note that, depending on the application, it may be desirable that the vibration also induce motion of the process material in a non z-axis direction. Therefore, the present invention may or may not incorporate a vibratory exciter or design elements that oscillate the material in a direction in addition to the z-axis. An example of this includes, but is not limited to a vibratory conveyor, where the majority of vibration occurs along the axis in which gravity acts. In a vibratory conveyor, it may also be desirable that the material interface have a component of vibration in the direction of the process material flow to facilitate motion in that direction.

Note that, in Figure 2.2, the present invention consists of spring 1, spring 2, and the isolated mount point. All other annotated components are auxiliary components that are outside the scope of the present invention. These include the Material Interface, Vibratory Exciter, Absorption Mount(s), and Base Structure. These auxiliary components are subject to change depending on the application of the invention. These auxiliary components may be connected to the invention by multiple means that include, but are limited to fasteners, clips, welds, adhesives, and wire.

The Material Interface can be, but is not limited to separation pans, screens, distribution pans, hoppers, and fluidized beds.

The Vibratory Exciter can be, but is not limited to a vibratory motor. The vibratory exciter could also be replaced with a weight in a passive (not powered) vibratory system.

The Absorption Mount(s) can be, but are not limited to a material, component, or assembly. This includes, but is not limited to coil springs, leaf springs, cantilevered springs, and rubber.

The Base structure can be any structure intended to hold a piece of vibration equipment in its intended location for operation. It could be made of a variety of materials including, but not limited to metal, steel, wood, plastic, and composites.

The present invention’s preferred configuration is shown in Figure 3.1. This shape was proven to be an effective implementation of the spring system shown in Figure 2.2. Figure 3.2 shows which parts of the preferred configuration are used as spring 1 and spring 2. The rest of the part should undergo a relatively small vibration during operation. Spring 1 is effectively 4 cantilevered springs in parallel. Spring 2 is effectively a doubled-back cantilevered spring. For the prototype, shown in Figure 3.1, the chosen dimensions for the preferred configuration were 390mm wide (y-axis), 400mm high (x-axis), and 4.8mm thick (z-axis). The prototype was made of low carbon steel. When combined with a material interface of 3kg and a vibratory exciter of 3kg, the system exhibited a natural frequency of 12hz. The material, thickness, and dimensions of the invention may be adjusted depending on the application. For a larger material interface, the overall dimensions of the invention can be increased. For a heavier material interface, or to achieve a higher natural frequency of vibration, the thickness may be increased. The present invention could be used as a spring system in a variety of vibratory equipment applications where the material interface is small and light (<1mm, <1g) or large and heavy (>10m, >10000kg). This can be achieved by modifying the dimensions, mount points, and effective spring constants of the present invention.

Figure 3.1: Preferred Configuration of the Present Invention

A drawing of the preferred configuration of the present invention. In this configuration, spring 1, spring 2, and the isolated mount points are constructed from a single piece of cut sheet material with no additional fabrication. Note that the intended vibration direction is along the z-axis (in and out of the page).

Figure 3.2: Preferred Configuration Springs

Illustrates which parts of the preferred configuration will function as spring 1 and spring 2 from the spring-mass diagram in figure 2.1. Note that the intended vibration direction is along the z-axis (in and out of the page).

Figure 3.3: Preferred Configuration Mount Points

Illustrates which parts of the preferred configuration will be used as connection points with the isolated mounts, material interface, and vibratory exciter. Note that the intended vibration direction is along the z-axis (in and out of the page).

Note that Figure 3.1 is the current preferred configuration of the invention. This is the current preferred configuration because the entire spring system (Spring 1 and Spring 2) and isolated mount is made of a single piece of material with minimal manufacturing. The design shown in Figure 3.1 can be manufactured by a variety of means including but not limited to laser cutting, plasma cutting, water jet cutting, additive manufacturing, 3d printing, and cnc machining. The current preferred configuration could use one or multiple materials including, but not limited to metal, steel, aluminum, plastic, composites, laminates, and wood.

The preferred configuration of the current invention (Figure 3.1) uses a specific shape to create the spring system shown in Figure 2.2 with minimal manufacturing. The combination of cantilever springs is easy to manufacture and at the same time restricts vibratory motion to the z-axis as is needed to make the spring system in Figure 2.2 work. A variety of shapes could accomplish this goal, and as such the shape used in the invention is not limited to that shown in Figure 3.1. The overall design shape and cantilevered springs could be curved, straight, or take a more complex shape constructed of splines, curves, lines, edges and more. The exact lengths, thickness, shape, configuration, and mounting methods used to create spring 1, spring 2, and the isolated mount area can vary greatly from what is shown in Figure 3.1. The preferred dimensions and shape used will depend on the application and tuning of the system.

To determine the appropriate dimensions of the design shown in Figure 3.1 for a given application, the appropriate material interface, size, oscillation frequency, and stroke must be determined based on the type and amount of process material. Equation 1 can be rewritten to yield the ideal spring constant of spring 1 and spring 2 given the desired frequency and the Material Interface mass.

Equation 2: 

The dimensions of the design shown in Figure 3.1 can be adjusted until the effective spring constants of spring 1 and spring 2 are equal to k1 and k2 from Equation 2 above. The spring constants of spring 1 and spring 2 can be calculated by hand, determined empirically, or computed with software. For example, increasing the material thickness will increase the spring constants of Spring 1 and 2. The spring constants are also affected by the elastic modulus of the material chosen. Possible materials for the design include, but are not limited to composites, laminates, metals, plastics, steel, titanium, aluminum, and more. Whichever material is chosen, it must have a fatigue stress that can withstand the cyclic load of the vibration at the required frequency and stroke. Figure 3.3 shows where different components are intended to mount to the preferred configuration.

Note that lengths, widths, and shapes of the various cantilevered springs in the preferred configuration are subject to change. The springs could be made thinner, longer, or more slender. The springs could taper or curve. The doubled-back spring could be longer, or have a different length ratio between the first set of springs and the second, doubled back set.

Additionally, the overall distance between the outer edges of the material interface and the material interface mount points should be small enough to provide stability for the assembly. In other words, the width (y) and length (x) of the material interface cannot be too large compared to that of the material interface mount points. The minimum required distance can be determined through trial and error for a given application.

A vibratory excitor must be selected that can impart enough force to the system to deflect spring 2 by the stroke required for the process material. After a vibratory exciter has been selected, mass can be added to the Material Interface or Vibratory Exciter as necessary until the mass of the two components is nearly equal.

Figures 4.1, 4.2, and 4.3 show a theoretical piece of vibratory equipment that uses the present invention’s preferred configuration (shown in red). In the shown assembly, running the vibratory exciter at the natural frequency of the system will cause the material interface to oscillate along the z-axis. The configuration shown in these figures reflects the configuration used in the working prototype, where the chosen dimensions for the preferred configuration were 390mm wide (y-axis), 400mm high (x-axis), and 4.8mm thick (z-axis). When combined with a material interface of 3kg and a vibratory exciter of 3kg, the system exhibited a natural frequency of 12hz.

Figure 4.1: Example Assembly - Right View

Shows the preferred configuration of the present invention in an example assembly. Here the material interface is shown as a simple distribution pan. Note that the intended direction of vibration of the Material Interface is along the z-axis.

Figure 4.2: Example Assembly - Isometric Bottom View

The preferred configuration of the present invention in an example assembly. Here the material interface is shown as a simple distribution pan.

Figure 4.3: Example Assembly - Isometric Top View

The preferred configuration of the present invention in an example assembly. Here the material interface is shown as a simple distribution pan.

Claims

I claim the products comprising any feature described in this document, either individually, or in combination with any feature, and in any configuration.