Patent Description:
Industrial and commercial floors are cleaned on a regular basis for aesthetic and sanitary purposes. There are many types of industrial and commercial floors ranging from hard surfaces such as concrete, terrazzo, wood, and the like, which can be found in factories, schools, hospitals, and the like, to softer surfaces such as carpeted floors found in restaurants and offices. Different types of floor cleaning equipment such as vacuums, scrubbers, sweepers, and extractors, have been developed to properly clean and maintain these different floor surfaces.

For example, vacuums incorporate the use of negative pressure to draw particulates into the vacuum in order to clean the particulates from a surface. The amount of positive or negative pressure throughout existing vacuum devices can be monitored by pressures sensors. However, the accuracy of measurements produced by such sensors can often be imprecise or inaccurate depending on where the pressures are measured and on what the pressure values are used for.

The inventors have recognized that there is a need for an improved system that overcomes the aforementioned disadvantages of imprecise and inaccurate pressure measurements within a vacuum device. <CIT> describes a method for the operation of a vacuum cleaner for the re-cleaning of a filter element enclosed by the vacuum cleaner during the operation of the vacuum cleaner, wherein a pressure measured value of a pressure sensor assigned to a volume in which the filter element is located and compared with a threshold value, wherein a clean gas valve located downstream of the filter element depending on an exceedance of the threshold to the ambient air, as well as an appropriate vacuum cleaner.

A method of operating a vacuum device includes operating the vacuum device. Voltage is provided to a turbine of the vacuum device to spin a rotary element of the turbine. A flow of air is drawn through a portion of the vacuum device in response to spinning the rotary element of the turbine. A pressure difference between a first location inside the vacuum device and a second location inside the vacuum device. The first location is disposed upstream relative to a direction of the flow of air from the turbine. The first location is also disposed downstream relative to the direction of the flow of air from a filter element of the vacuum device. An amount of voltage across the turbine is adjusted in response to the measured pressure difference. A performance characteristic of the turbine is monitored.

A method of assembling a vacuum device according to appended claim <NUM>.

A vacuum device includes a turbine, a filter element, a housing, a sensor, and a controller. The turbine is configured to draw a flow of air a flow of air through a portion of the vacuum device. A filter element is disposed upstream from and in fluid communication with the turbine. The housing defines a chamber that is disposed upstream from and in fluid communication with the filter element. The sensor is disposed inside of the vacuum device to sense a pressure of the flow of air at a location between the filter element and the turbine. The sensor is configured to measure a pressure difference between the first location inside the vacuum device and a second location inside the vacuum device. The controller is electrically connected to the turbine and is configured to adjust an amount of voltage across the turbine in response to a measured pressure difference.

In existing vacuum devices, pressure measurements can be taken upstream of a filter element. However, measurements of pressure taken upstream from the filter element can produce unprecise or inaccurate measurements within the vacuum product. Other existing vacuum devices take a reference or set-point pressure at a location external to the vacuum device, which may require a hole in the vacuum device itself in order to obtain a measurement of the external pressure.

The inventors have recognized, among other things, that a problem to be solved with existing vacuum devices is the lack of precision and accuracy with pressure measurements taken upstream of the filter elements.

The present subject matter can help provide a solution to these and other problems such as by measuring a pressure within the vacuum at a location between the filter element and the turbine with a second reference pressure measurement taken from within the vacuum. In view of this placement, there is no need for an externally positioned pressure sensor thereby eliminating a need to make a hole in the device itself to obtain a measurement of the external pressure. For example, a pressure of an ambient environment external to the vacuum device is used as a reference pressure, but there is no specific measurement point outside of the device. The disclosure presents a method of measuring a pressure difference between two locations in the device with one sensor, adjusting the performance of the turbine by adjustment of the voltage across the turbine, and analyzing the performance of the turbine (e.g., pressure versus air flow). The proposed configuration enables more optimized power consumption as well as precise measurement of power and voltage usage to fulfill legal requirements for minimum air speed.

Referring now to <FIG> shows a cross-section system view of vacuum device <NUM>. In one exemplary embodiment, vacuum device <NUM> may be a vacuum cleaning machine. I other exemplary embodiments, vacuum device <NUM> may be an industrial vacuum cleaner, a consumer vacuum cleaner, a high pressure washer, a scrubber, or other cleaning machines involving the flow of a fluid. Vacuum device <NUM> includes housing <NUM>. Housing <NUM> can be a structural framework of solid material that is disposed throughout different portions of vacuum device <NUM>. In one example, housing <NUM> can be a single monolithic piece of material. In other examples housing <NUM> can be an assembly of a plurality of pieces of solid material that form housing <NUM>. In one exemplary embodiment, housing <NUM> defines compartment <NUM>.

Compartment <NUM> is an opening or cavity formed within and defined by a section of housing <NUM>. In one example, compartment <NUM> can be defined in-part by housing <NUM> and in-part by filter element <NUM>. In this example, compartment <NUM> may have a tubular shape. Compartment <NUM> is disposed adjacent to and in fluid communication with filter element <NUM>. In an exemplary embodiment, compartment <NUM> surrounds filter element <NUM>.

Filter element <NUM> is a filter for removing particulates from air. Filter element <NUM> is disposed inside of housing <NUM> and in fluid communication with compartment <NUM>. Filter element <NUM> is disposed to remove particulates from air flow F passing through filter element <NUM>. In this example, filter element <NUM> is disposed downstream from compartment <NUM> as defined by a direction of flow of air flow F as shown in <FIG>. As used herein, the term "air flow" may be used interchangeably with the term "flow of air.

Turbine <NUM> includes a motor configured to draw a flow of air through turbine <NUM>. In an exemplary embodiment, turbine <NUM> is disposed to create a pressure differential across various portions of vacuum device <NUM> in order to drive or draw air flow F through the different portions of vacuum device <NUM>. Additionally, or alternatively, turbine <NUM> may be configured to draw air F through a portion of vacuum device <NUM>.

Electronics compartment <NUM> is section of vacuum device <NUM> define by a portion of housing <NUM>. In this example, electronics compartment <NUM> is fluidly isolated from compartment <NUM>. Electronics compartment is disposed to house various electronics components of vacuum device <NUM>.

Pressure measurement system <NUM> is a system for measuring an amount of air pressure within a portion of vacuum device <NUM>. In this example, pressure measurement system <NUM> is in fluid communication with air flow F at a location near a downstream side of filter element <NUM>. Pressure measurement system <NUM> includes sensor <NUM>.

Sensor <NUM> is device for measure a pressure, velocity, or a combination of both of a fluid. In an exemplary embodiment, sensor <NUM> may be an air velocity measurement sensor disposed to measure a velocity, flow rate, or a combination thereof of air flow F as air flow F flows from filter element <NUM> to turbine <NUM>. In another exemplary embodiment, sensor <NUM> may be a pressure measurement sensor disposed to measure a pressure of air flow F as air flow F flows from filter element <NUM> to turbine <NUM>. In such an embodiment, a measured pressure amount may be used to determine an actual speed or velocity of air flow F through turbine <NUM>, through vacuum device <NUM>, or a combination thereof. Sensor <NUM> is disposed in electronics compartment <NUM>. As will be discussed further with respect to the remaining figures, sensor <NUM> is disposed to sense a pressure of air flow F at a location between filter element <NUM> and turbine <NUM>. In an exemplary embodiment, sensor <NUM> is configured to measure a pressure difference between a first location inside vacuum device <NUM> and a second location inside vacuum device <NUM>.

Cage <NUM> is frame of solid material. In this exemplary embodiment, cage <NUM> is disposed inside of and along filter element <NUM>. Cage <NUM> is attached to a portion of housing <NUM> and provides structural support to filter element <NUM>, to housing <NUM>, and to other portions of vacuum device <NUM>.

Center compartment <NUM> is an open space or cavity. Center compartment <NUM> is defined by cage <NUM>, such as by an inner radial surface of cage <NUM>. Center compartment <NUM> is in fluid communication with filter element <NUM> via openings or slits in cage <NUM>. Center compartment <NUM> is also in fluid communication with turbine <NUM>. In this exemplary embodiment, center compartment <NUM> is disposed to receive air flow F from filter element <NUM>.

<FIG> also shows ambient environment <NUM>. Ambient environment <NUM> is positioned externally from vacuum device <NUM>. In an exemplary embodiment, housing <NUM> fluidly isolates vacuum device <NUM> from ambient environment <NUM> such that areas or portions within vacuum device <NUM> (e.g., within and/or defined by housing <NUM>) are fluidly isolated from ambient environment <NUM>.

In one exemplary embodiment, vacuum device <NUM> can define a downstream direction of air flow F. As defined by a direction of air flow F shown in <FIG>, compartment <NUM> is disposed upstream from filter element <NUM>. Filter element <NUM> is disposed downstream from compartment <NUM> and upstream from center compartment <NUM>, center compartment <NUM> is disposed downstream from filter element <NUM> and upstream from turbine <NUM>, and turbine <NUM> is disposed downstream from center compartment <NUM>.

Referring now to <FIG> shows a zoomed-in cross-section view of vacuum device <NUM> with pressure measuring system <NUM>. In <FIG>, some of the components of vacuum device are shown with simplified representations so as to provide clarity of discussion with respect to vacuum device <NUM> and components thereof.

As shown in <FIG>, turbine <NUM> includes rotary element <NUM>. In an exemplary embodiment, rotary element <NUM> may include a rotor assembly that is configured to draw air into and through turbine <NUM>. In this way, turbine <NUM> can create a pressure differential so as to draw air flow F through vacuum device <NUM>.

Turbine <NUM> also includes inlet <NUM> and outlet <NUM>. Inlet <NUM> is an opening or a port in a housing of turbine <NUM> that is configured to receive a portion of air flow F from filter element <NUM>. Similarly, outlet <NUM> is an opening or a port in the housing of turbine <NUM> that is configured to dispense a portion of air flow F from turbine <NUM>.

In an exemplary embodiment, sensor <NUM> includes first port <NUM> and second port <NUM>. Both of first port <NUM> and second port <NUM> are openings through which a fluid (e.g., air) may flow. In an exemplary embodiment, first port <NUM> opens up into and is in fluid communication with electronics compartment <NUM>. In other exemplary embodiments, first port <NUM> may open up into and be in fluid communication with one or more internal chambers or compartments of vacuum device that are fluidly isolated from ambient environment <NUM>. Second port <NUM> is in fluid communication with air flow F via line <NUM> and tube <NUM>. In an embodiment, first port <NUM> and second port <NUM> are fluidly isolated from each other with a membrane that prevents a flow of air across the membrane. In such an embodiment, a movement of the membrane can be measured and converted into an output signal defining a pressure difference between first port <NUM> and second port <NUM>.

Line <NUM> is a conduit configured for transporting a fluid (e.g., air). In this exemplary embodiment, line <NUM> may be a tube of flexible material that is sealably attached to second port <NUM> of sensor <NUM> and to an end of tube <NUM>. Line <NUM> is in fluid communication with sensor <NUM> via second port <NUM> and with air flow F via tube <NUM>.

Tube <NUM> is a tube of solid material that is configured to transport a fluid (e.g., air). Tube <NUM> may be separate from or integrally formed with a portion of housing <NUM>. Tube <NUM> is in fluid communication with sensor <NUM> via line <NUM> and with air flow F at first location <NUM>.

First location <NUM> is a location within vacuum device that is in direct fluid communication with air flow F. In this exemplary embodiment, first location <NUM> may be disposed upstream relative to a direction of the flow of air flow F from turbine <NUM>. First location <NUM> may also be disposed downstream relative to the direction of the flow of air flow F from filter element <NUM>. As shown in <FIG>, the direction of the flow of air of air flow F is depicted by a direction of arrowheads associated with the line segments corresponding to air flow F. In an exemplary embodiment, first location <NUM> may be a point at which sensor <NUM> measures a velocity, a pressure, or a combination thereof of air flow F as air flow F passes from filter element <NUM> to turbine <NUM>.

Vacuum device also includes controller <NUM>. In this exemplary embodiment, controller may be positioned in electronics compartment <NUM>. In other exemplary embodiments, controller <NUM> may be located in another part of or upon an external surface of vacuum device <NUM>. Controller <NUM> is electrically connected to turbine <NUM> and to sensor <NUM>. Controller <NUM> is configured to control an amount of voltage across turbine <NUM>. In an exemplary embodiment, controller <NUM> is configured to adjust an amount of voltage across turbine <NUM> in response to a measured pressure difference between first location <NUM> and second location <NUM>.

Second location <NUM> is a location positioned within vacuum device <NUM>. In this exemplary embodiment, second location <NUM> may be positioned inside of electronics compartment <NUM>. In other exemplary embodiments, second location <NUM> may be positioned such that second location <NUM> is fluidly isolated from air flow F and from ambient environment <NUM>. Additionally, or alternatively, a pressure at second location <NUM> is approximately equal to an ambient pressure of ambient environment <NUM> outside of housing <NUM> of vacuum device <NUM>. In this way, the pressure at second location <NUM> may provide reference to the actual atmospheric pressure.

As provided herein, the disclosure presents in <FIG> (and in <FIG>) the capability of measuring a pressure within the vacuum at first location <NUM> between filter element <NUM> and turbine <NUM> with a second reference pressure measurement taken at second location <NUM> from within vacuum device <NUM>. In view of this placement, there is no need for an externally positioned second sensor thereby eliminating a need to make a hole in vacuum device <NUM> itself to obtain a measurement of a pressure of ambient environment <NUM> external to vacuum device <NUM>.

Referring now to <FIG> shows a simplified schematic view of vacuum device <NUM> with pressure measuring system <NUM>.

In this exemplary embodiment, vacuum device <NUM> defines a downstream direction of air flow F. As defined by the direction of the arrowheads associated with air flow F shown in <FIG>, compartment <NUM> is disposed upstream from filter element <NUM>. Filter element <NUM> is disposed downstream from compartment <NUM> and upstream from turbine <NUM>. First location <NUM> is disposed at a point between filter element <NUM> and turbine <NUM>. Sensor <NUM> is in fluid communication with air flow F at first location <NUM>.

The positioning of sensor <NUM> and first location <NUM> (e.g., the point at which sensor <NUM> measures a velocity, a pressure, or a combination thereof of air flow F) enables a more precise measurement and/or calculation of a usage of power and voltage of vacuum device <NUM>. Such measurements and calculations of power and voltage usage of vacuum device <NUM> in turn provide benefits of being able to better fulfill legal requirements for vacuum devices, such as with respect to minimum air speed, power consumption, or other performance requirements.

Referring now to <FIG> shows a flowchart of method <NUM> of operating vacuum device <NUM>.

At step <NUM>, method <NUM> may include operating vacuum device <NUM>. Step <NUM> may also include steps <NUM>-<NUM>. At step <NUM>, method <NUM> may include providing voltage across turbine <NUM> to spin rotary element <NUM> of turbine <NUM>. At step <NUM>, method <NUM> may include drawing a flow of air through a portion of vacuum device <NUM> in response to spinning rotary element <NUM> of turbine <NUM>. At step <NUM>, method <NUM> may include passing the flow of air through filter element <NUM>.

At step <NUM>, method <NUM> may include measuring, with sensor <NUM>, a pressure difference between first location <NUM> inside vacuum device <NUM> and second location <NUM> inside vacuum device <NUM>. As discussed above, first location <NUM> may be disposed upstream relative to a direction of the flow of air from turbine <NUM>, wherein first location <NUM> may be disposed downstream relative to the direction of the flow of air from filter element <NUM>. In an exemplary embodiment, a pressure at second location <NUM> is approximately equal to an ambient pressure outside of vacuum device <NUM>. Additionally, or alternatively, second location <NUM> is fluidly isolated from ambient environment <NUM> external to vacuum device <NUM>. Step <NUM> may also include steps <NUM>-<NUM>.

At step <NUM>, method <NUM> may include detecting a variation in the measured pressure difference that may be greater than a predetermined amount of variation of pressure difference. At step <NUM>, method <NUM> may include adjusting, with a filter of controller <NUM>, a value of the variation in the measured pressure difference due to an occurrence of turbulence in the flow of air at first location <NUM>. For example, if peak (e.g., a maximum or minimum value) in the measured pressure difference occurs, the pressure difference value occurring at that peak can be removed from the step of analyzing the performance characteristic.

In an exemplary embodiment, the filter of controller <NUM> may be an algorithm in software utilized by controller <NUM>. At step <NUM>, method <NUM> may include one of decreasing a value of the measured pressure difference that may be greater than a first threshold value (such as greater than <NUM> Pa, such as greater than <NUM>, such as greater than <NUM> Pa), increasing a value of the measured pressure difference that may be less than the first threshold value, or a combination thereof in response to a detected variation in the measured pressure difference that may be greater than the predetermined amount of variation of pressure difference (such as <NUM> Pa, such as <NUM> Pa, such as <NUM> Pa, such as <NUM> Pa). In an exemplary embodiment, the value of the measured pressure difference may be adjusted (e.g., decreased or increased) by an algorithm stored in controller <NUM>. As will be discussed with respect to the following figures, method <NUM> may also include steps <NUM>-<NUM>.

Referring now to <FIG> shows a flowchart of additional steps of method <NUM> of operating vacuum device <NUM>. In particular, <FIG> shows steps <NUM>-<NUM> of method <NUM>. As described herein, steps <NUM>-<NUM> may be additional steps that follow after steps <NUM>-<NUM> from <FIG>. At step <NUM>, method <NUM> may include adjusting an amount of voltage across (via an amount of current supplied to) turbine <NUM> with controller <NUM> in response to the measured pressure difference.

At step <NUM>, method <NUM> may include monitoring a performance characteristic of turbine <NUM>. In an exemplary embodiment, the performance characteristic of turbine <NUM> may be a flow rate of the flow of air (e.g., air flow F). In such an exemplary embodiment, the flow rate of the flow of air may be determined by a measured or calculated flow rate of the flow of air through turbine <NUM>. Step <NUM> may also include steps <NUM>-<NUM>. At step <NUM>, method <NUM> may include analyzing the performance characteristic of turbine <NUM>. Step <NUM> may also include step <NUM>. At step <NUM>, method <NUM> may include determining whether a ratio of the measured pressure difference to the flow rate of the flow of air may be within or outside of a predetermined range. In an embodiment, if the ratio of the measured pressure difference to the flow rate of the flow of air may be within or outside of the predetermined range, a user, controller <NUM>, or a combination thereof can adjust an amount of voltage across the turbine in response to the flow rate of the flow of air being within or outside of the predetermined range.

In an embodiment, the flow rate of the flow of air may be determined in-part by and/or dependent upon the diameter of a hose utilized by vacuum device <NUM>. In view of this, the ratio of the measured pressure difference to the flow rate of the flow of air may also be determined in-part by and/or dependent upon the diameter of the hose. As used herein, the term "hose" may refer to any of a hose extending from the vacuum device out to a vacuum attachment configured to draw dirt into the hose, an intermediate hose extending from turbine <NUM> to an attachment hose, another hose disposed inside of housing <NUM>, or any combination thereof.

The following table displays example values of hose diameters and flow rates.

Tables <NUM>, <NUM>, and <NUM> include example values of the ratio of the measured pressure difference ("ΔP") to the flow rate of the flow of air for example values <NUM> Pa, <NUM> Pa, and <NUM> Pa, respectively, in view of the flow rates values provided in Table <NUM> above.

In an embodiment, the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air may be based on comparisons of set values for pressure difference.

For a particular hose diameter (see e.g., left-most column of Tables <NUM>-<NUM>), the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air may be defined as the range between the Ratio (ΔP / Flow Rate) value at <NUM> Pa for that particular hose diameter and the Ratio (ΔP / Flow Rate) value at <NUM> Pa for that particular hose diameter. For example, the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, and such as <NUM> to <NUM>.

In another embodiment, the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air may be defined as the range between the Ratio (ΔP / Flow Rate) value at <NUM> Pa for that particular hose diameter and the Ratio (ΔP / Flow Rate) value at <NUM> Pa for that particular hose diameter. For example, the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air such as <NUM> to <NUM>, such as <NUM> to1. <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, and such as <NUM> to <NUM>.

In yet another embodiment, the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air may be defined as the range between the Ratio (ΔP / Flow Rate) value at <NUM> Pa for that particular hose diameter and the Ratio (ΔP / Flow Rate) value at <NUM> Pa for that particular hose diameter. For example, the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, such as <NUM> to <NUM>, and such as <NUM> to <NUM>.

Although associated with specific hose diameters, the example values provided herein for flow rate and for the ratio of the measured pressure difference to the flow rate of the flow of air may also be independent of hose diameter.

At step <NUM>, method <NUM> may include detecting turbulence in the flow of air at first location <NUM>. At step <NUM>, method <NUM> may include altering, with an algorithm, the measured pressure difference.

As provided herein, the proposed disclosure of vacuum device <NUM> with pressure measurement system <NUM> and method <NUM> provide for continuous adjustment of the performance of vacuum device <NUM> through adjustment of the voltage across turbine <NUM> in response to the pressure difference between first location <NUM> and second location <NUM>. Vacuum device <NUM> with pressure measurement system <NUM> and method <NUM> enable the performance of vacuum device to be independent from the voltage across turbine <NUM> thereby providing additional levels of control. Also, the performance of vacuum device <NUM> is adjustable to be with legally required limits. Moreover, an alarm level of vacuum device <NUM> can be more reliable than existing devices. In addition, the flow of air through vacuum device <NUM> can be set at certain levels in the interest of safety. In view the above, power management of vacuum device can be optimized and further adjusted in response to floor type (e.g., hard floor, carpet, etc.) and floor detection.

In another exemplary embodiment, a set of steps 110A-114A, a set of steps 110B-114B (see e.g., <FIG>), or a combination thereof may replace steps <NUM>-<NUM>. For example, <FIG> shows a flowchart of additional, or alternative, steps of method <NUM> of operating vacuum device <NUM>.

Referring now to <FIG>, at step 110A, method <NUM> may include detecting the flow rate of the flow of air. At step 112A, method <NUM> may include determining, with controller <NUM>, if the flow rate of the flow of air may be below a predetermined value. In one exemplary embodiment, the predetermined value of the flow rate of the flow of air may be <NUM> meters per second. At step 114A, method <NUM> may include providing a notification that the flow rate of the flow of air may be less than the predetermined value.

Referring now to <FIG> shows a flowchart of additional, or alternative, steps of method <NUM> of operating vacuum device <NUM>. At step 110B, method <NUM> may include detecting the flow rate of the flow of air. At step 112B, method <NUM> may include determining, with controller <NUM>, if the flow rate of the flow of air may be below a predetermined value. At step 114B, method <NUM> may include increasing the amount of voltage across turbine <NUM> in response to the flow rate of the air flow being less than the predetermined value.

Referring now to <FIG> shows a flowchart of method <NUM> of assembling vacuum device <NUM>. At step <NUM>, method <NUM> may include mounting turbine <NUM> within vacuum device <NUM>. turbine <NUM> defines a downstream direction from the inlet of turbine <NUM> to the outlet of turbine <NUM>, wherein turbine <NUM> may be configured to draw a flow of air through a portion of vacuum device <NUM>. At step <NUM>, method <NUM> may include positioning filter element <NUM> in fluid communication with and upstream from turbine <NUM>.

At step <NUM>, method <NUM> may include disposing sensor <NUM> inside of vacuum device <NUM>, wherein sensor <NUM> may be configured to sense a pressure difference between first location <NUM> inside of vacuum device <NUM> and second location <NUM> within vacuum device <NUM>, wherein first location <NUM> may be disposed upstream relative to a direction of the flow of air from turbine <NUM>, wherein first location <NUM> may be disposed downstream relative to the direction of the flow of air from filter element <NUM>. At step <NUM>, method <NUM> may include fluidly connecting sensor <NUM> to first location <NUM> disposed between filter element <NUM> and turbine <NUM>. Step <NUM> may also include step <NUM>. At step <NUM>, method <NUM> may include positioning sensor <NUM> in a portion of vacuum device <NUM> that may be fluidly isolated from ambient environment <NUM> external to vacuum device <NUM>.

The vacuum devices and associated methods described herein provide advantages over existing vacuum devices such as enabling more optimized power consumption, precise measurement of power and voltage usage, both of which support fulfillment of legal requirements for minimum air speed.

Each of these non-limiting examples can stand on its own or can be combined in various permutations or combinations with one or more of the other examples.

Optionally, monitoring the performance characteristic of the turbine may comprise analyzing the performance characteristic of the turbine.

Optionally, the performance characteristic of the turbine comprises a flow rate of the flow of air, wherein analyzing the performance characteristic may comprise determining whether a ratio of the measured pressure difference to the flow rate of the flow of air is within a predetermined range.

Optionally, the predetermined range of the ratio of the measured pressure difference to the flow rate of the flow of air may be from <NUM> to <NUM>.

Optionally, measuring the pressure difference between the first location in the vacuum device and the second location in the vacuum device may comprise: detecting a variation in the measured pressure difference that is greater than a predetermined amount of variation of pressure difference; and adjusting, with a filter of the controller, a value of the variation in the measured pressure difference due to an occurrence of turbulence in the flow of air at the first location.

Optionally, a value of the measured pressure difference that is greater than a first threshold value may be decreased, increasing a value of the measured pressure difference that is less than the first threshold value may be increased, or a combination thereof in response to a detected variation in the measured pressure difference that is greater than the predetermined amount of variation of pressure difference.

Optionally, monitoring the performance characteristic of the turbine may comprise: detecting turbulence in the flow of air at the first location; and altering, with an algorithm, the measured pressure difference.

Optionally, a pressure at the second location may be approximately equal to an ambient pressure outside of the vacuum device.

Optionally, the second location may be fluidly isolated from an ambient environment external to the vacuum device.

Optionally, the flow of air may be passed through the filter element before measuring the pressure difference between the first location in the vacuum device and the second location in the vacuum device.

Optionally, the performance characteristic of the turbine may comprise a flow rate of the flow of air, wherein the method may further comprise: detecting the flow rate of the flow of air; determining, with the controller, if the flow rate of the flow of air is below a predetermined value; and providing a notification that the flow rate of the flow of air is less than the predetermined value.

Optionally, the performance characteristic of the turbine may comprise a flow rate of the flow of air, wherein the method may further comprise: detecting the flow rate of the flow of air; determining, with the controller, if the flow rate of the flow of air is below a predetermined value; and increasing the amount of voltage across the turbine in response to the flow rate of the air flow being less than the predetermined value.

A method of assembling a vacuum device includes mounting a turbine within the vacuum device. The turbine includes an inlet and an outlet and defines a downstream direction from the inlet to the outlet. The turbine is configured to draw a flow of air through a portion of the vacuum device. A filter element is positioned in fluid communication with and upstream from the turbine. A sensor is disposed inside of the vacuum device and is configured to sense a pressure difference between a first location inside of the vacuum device and a second location within the vacuum device. The first location is disposed upstream relative to a direction of the flow of air from the turbine. The first location is also disposed downstream relative to the direction of the flow of air from the filter element.

Optionally, fluidly connecting the sensor to the first location may comprise positioning the sensor in a portion of the vacuum device that is fluidly isolated from an ambient environment external to the vacuum device.

Optionally, the sensor may be disposed in a portion of the vacuum device that is fluidly isolated from an ambient environment external to the vacuum device.

The drawings show, by way of illustration, specific embodiments in which the disclosure can be practiced.

Claim 1:
A method (<NUM>) of operating a vacuum device (<NUM>), the method (<NUM>) comprising:
operating the vacuum device (<NUM>), wherein operating the vacuum device (<NUM>) comprises:
providing voltage across a turbine (<NUM>) of the vacuum device (<NUM>) to spin a rotary element (<NUM>) of the turbine (<NUM>); and
drawing a flow of air (F) through a portion of the vacuum device (<NUM>) in response to spinning the rotary element (<NUM>) of the turbine (<NUM>);
measuring, with a sensor (<NUM>), a pressure difference between a first location (<NUM>) inside the vacuum device (<NUM>) and a second location (<NUM>) inside the vacuum device (<NUM>), wherein the first location (<NUM>) is disposed upstream relative to a direction of the flow of air (F) from the turbine (<NUM>), wherein the first location (<NUM>) is disposed downstream relative to the direction of the flow of air (F) from a filter element (<NUM>) of the vacuum device (<NUM>);
adjusting, with a controller (<NUM>), an amount of voltage across the turbine (<NUM>) in response to the measured pressure difference; and
monitoring a performance characteristic of the turbine (<NUM>).