Patent Application
20200072207
The present invention relates generally to a compressor installation which includes a belt guard that comprises a compressor silencer for reducing the noise emitted from certain compressors, especially reciprocating piston air compressors.
Compressor installations may include a motor, a gas compressor driven by the motor, and a storage tank to store gas that has been compressed by the gas compressor. The motor may be an electric motor, an internal combustion engine, or another type of motor. The gas may be air or another gas. The compressor may be a reciprocating piston compressor, a centrifugal compressor, a scroll compressor, a screw compressor having male and female compressor elements, or another type of compressor. The storage tank may be a canister, reservoir, or other type of tank, that contains the compressed gas until it is used to power a device such as a tool, or used by an end user, or released to atmosphere. In most cases, air is drawn into an inlet air side of the gas compressor from the atmosphere, and then mechanically compressed, e.g., via pistons or male and female rotors, into a smaller volume in the compression chamber of the gas compressor. The compressed gas flows through a pipe or the like, to the storage tank. During the compression process, due to the large volume of air provided through the air inlet of the compressor, noise is generated at the air inlet or suction side.
In a reciprocating compressor, which is widely used in various industrial and domestic applications, the reciprocating compressor and motor with belt drive can be mounted on a tank. The motor is used to drive the belt in a pulley system to rotate a crankshaft that moves the piston(s) in a reciprocating manner, where gas enters the suction side, typically through an inlet manifold, is compressed via the piston(s) being driven in a reciprocating manner, and then discharged at high pressure into a tank.
However, during operation of the reciprocating compressor, noise is emitted from the air inlet or suction side of the reciprocating compressor when the air is drawn through the inlet manifold, e.g., due to the turbulence of the air moved through the inlet. Typically, the prior art reciprocating compressor has little to no provisions to reduce the noise it generates or employs conventional structures to reduce this noise. For example, one conventional structure draws the inlet air through a large, bulky, and remotely mounted baffling box, where such structure is costly and restricts the inlet air flow by employing a long tube that connects the suction side or air inlet of the compressor to the large baffling box, which reduces the efficiency of the compressor.
In view of such drawbacks, there is a need to provide a simpler, smaller, and more cost-effective structure for reducing the noise generated at the air inlet of compressors that does not reduce the efficiency of the compressor.
The present invention is provided to solve the deficiencies of the prior art by providing improvements over the prior art. It is an object of the present invention to provide a belt guard that includes an compressor silencer that costs less, is much smaller, and can be attached directly to the compressor inlet to reduce or eliminate restriction to the inlet gas flow. The gas is typically air.
In one embodiment of the invention, since a belt guard is required on all belt driven units, an air compressor silencer is provided inside the belt guard, which can then be attached directly to the air inlet of a compressor. The air compressor silencer is configured to reduce and/or eliminate the noise at the air inlet (drawn through the belt guard) to provide a quieter compressor without adding significant extra costs and without significantly reducing efficiency. In one embodiment of the invention, the air compressor silencer comprises a spirally shaped silencer core, where the spirally shaped silencer core comprises at least one spiral chamber having a core inlet and a core outlet.
In another embodiment of the invention, the spiral chamber comprises hollow walls forming the spiral chamber, where the hollow walls comprise sound absorbing material along an inside and/or along an outside wall of the spiral chamber. The spiral chamber can be made of metal, plastic, a composite material, or a combination thereof and/or include material to dampen the noise.
In order to reduce costs and size, the air compressor silencer is incorporated into the belt guard to eliminate the need for a separate housing for the air compressor silencer and/or the inlet air filter. A tube, e.g., short tubing, can then be used to connect the air compressor silencer to the compressor intake/air inlet.
In yet another embodiment of the invention, a compressor installation comprises a motor for driving a compressor element, a compressor element to compress a gas, a belt connected to the compressor shaft of the compressor element and a motor shaft of the motor, e.g., mechanically coupling the motor to the compressor element, and a belt guard comprising a housing configured to house the belt. The belt guard comprises a front cover, a back cover, and an air compressor silencer. The front cover includes an accommodation portion. The air compressor silencer is provided inside the housing in the accommodation portion. The air compressor silencer comprises a spirally shaped silencer core and the spirally shaped silencer sore comprises at least one spiral chamber comprising a core inlet and a core outlet.
The features and objects of the present invention are more clearly understood from the detailed description taken in conjunction with the accompanying drawings, in which:
In the various figures, similar elements are provided with similar reference numbers. It should be noted that the drawing figures are not necessarily drawn to scale, or proportion, but instead are drawn to provide a better understanding of the components thereof, and are not intended to be limiting in scope, but rather provide exemplary illustrations.
The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto and can be combined interchangeably with certain features in the different embodiments.
As illustrated in
An air compressor silencer 230 is provided inside the housing in the accommodation portion 212. The air compressor silencer 230 comprises a spirally shaped silencer core, where the spirally shaped silencer core comprises at least one spiral chamber having a core inlet and a core outlet. The core outlet of the air compressor silencer 230 is configured to be coupled to the connection portion 222 of the back cover 220.
Specifically, the air compressor silencer 230 is provided in the accommodation portion 212 in a way such that air is drawn into a core inlet of the air compressor silencer 230 through an inlet side of the accommodation portion 212 and discharged through the core outlet to the air inlet of the compressor. For example, in one embodiment of the invention, a first end seal 232 abuts one end of the spiral chamber of the air compressor silencer 230 and a second end seal 234 abuts the second end of the spiral chamber of the air compressor silencer 230, where the first and second end seals are provided to seal the spirally shaped silencer core so that all of the air flow is forced through the spirally shaped silencer core. That is, the air flow is guided from the inlet side of the accommodation portion 212 through the core inlet of the spiral chamber and exits through the aperture in the center of the second end seal 234 and into the connection portion 222 of the back cover 220. The end seals 232, 234 are constructed of a composite material or rubber to seal the spiral chamber and direct the air flow through the air compressor silencer 230. While at least one spiral chamber is illustrated in this embodiment, a single spiral chamber or more than two spiral chambers can be used, where the number of spiral chambers are determined based on a number of factors, including the size of the compressor element and desired airflow amount.
A filtering element that comprises a filter screen 240 and a filter 242 can be provided at the inlet side of the accommodation portion 212 by being slid into the slot 214 of the front cover 210 to enclose the air compressor silencer 230 inside the accommodation portion 212, where the air flow is first filtered by the filter 242 before entering into the air compressor silencer 230. The filter screen 240 is provided as a supporting surface for the filter 242. The filter 242 can include a variety of filtering media for example, coalescing filters, particulate filters, and carbon filters, to remove at least solid particles, liquids, aerosols, hydrocarbon vapours, etc. The filtering element can be further configured to reduce high frequency noise, e.g., based on the material and construction of the filtering element, e.g., using noise reducing material such as composite material, and firmly mounting the filter screen with the accommodation portion, e.g., clips, screws, etc. The slot 214 of the front cover 210 allows the removal and servicing of the filter screen 240 and/or the filter 242 without having to remove the front cover 210 of the belt guard.
However, more or less windings are within the scope of the invention. The spiral shape of the spiral chamber prevents a straight path for the sound to travel, where the sound is instead reflected from all surfaces causing noise cancelation and attenuation. For example, the spiral windings provide a sealed surface for a broad spectrum of sound frequencies that are diffused or absorbed by the spiral chamber. The number of windings that are appropriate depends on the application and volume of air to be passed through the air compressor silencer 230. The air compressor silencer reduces air flow restriction to the compressor by not only providing a wider inlet opening, but reduces the noise by creating an extended and indirect path for the noise generated at the air inlet of the compressor to travel.
Furthermore, as shown in
Noise reduction can be further enhanced by coating the spiral chamber with a sound absorbing material, such as sound proofing paint or gel, foam, fiberglass, ceramics or the like. This concept can be stacked for increased noise reduction. The end seals 232, 234 can also be coated with the sound absorbing material for further noise reduction.
The spirally shaped silencer core can be made of a composite material, such as plastic, rubber, metal, carbon, natural fibers, fiberglass, or a combination thereof, to absorb a broad spectrum of frequencies and can further include porous or corrugated tubes or foams inside the spirally shaped silencer core to further absorb noise.
Referring back to
Typically, in such compressor elements, noise is generated at the air inlet due to the suction of air, however, in the present invention, the noise from the suction of air is reduced and/or eliminated by the air compressor silencer 230 inside the belt guard 200. Without limiting the invention by theory, it is understood that the spiral chamber is configured to create an extended and indirect path for the sound to travel by forcing the air to travel through the several windings of the spiral chamber.
In view of such structure and features, the present invention solves the deficiencies of the prior art by providing a compact design in which a belt driven compressor includes a belt guard that includes an air compressor silencer which includes a spirally shaped silencer core that is configured to reduce and/or eliminate noise generated when air is drawn into a compressor. This is an improvement over the prior art in several ways. These features cost less than a baffle box provided at an air inlet of a compressor. The present invention allows a smaller size silencer due to the compact arrangement of the silencer inside the belt guard, and may be attached directly to the compressor air inlet to reduce or eliminate restriction to the inlet air flow. This design may further include a filter for filtering the inlet air, which further eliminates the need for an additional air filter on the air inlet of the compressor. The filter may be easily changed through the slot 214.
The invention discussed herein is directed to specific embodiments, but the design is not limited to the description of the exemplary invention but only by the scope of the appended claims. As a result, there are multiple embodiments that employ the beneficial characterises of the invention, each providing a different advantage and which are combinable and/or interchangeable with various aspects of the different embodiments of the invention that do not depart from the spirit and scope of the invention.
This application claims priority to provisional application No. 62/723,698, filed Aug. 28, 2018, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62723698 | Aug 2018 | US |
