The present description relates, in general, to an assembly adaptable to shafts or axis of devices having them, and more particularly, to an assembly for measuring the rotational speed on shafts of devices having them.
A wide range of devices with rotating shafts or axis are currently used in industry to perform the operations for which they are intended. Drilling, stirring, mixing-homogenizing, torque transmission activities and devices, among others, are some examples wherein rotating shafts are used.
It is convenient to know the angular velocity or revolutions per minute (rpm) of the rotating shafts in the devices to establish if the device is optimally performing in a given process. In some cases, like in the homogenization of liquid fluids, it is necessary to know the rpm value at which the shaft is rotating by the torque transmission of a stirring motor to know if a correct homogenization of the constituent elements of a fluid is being conducted. In other cases, for example, in the production of polyethylene, a stirring shaft rotating at an rpm value higher than a certain preset rpm value for the process may destroy the product, i.e., the expected amount of solid polyethylene will not be formed.
Some solutions proposed to measure rpm have been through electronics or by means of sophisticated control devices, such as PLC. These options, widely known, are regularly costly both in terms of purchasing and maintenance of them or repairing in case of failure, in addition to the time required to put them back into operation. In addition, these solutions can often give false measurements, i.e., erroneous rpm values, for example, for misadjustment or decalibration of the device having the shaft or the measuring electronic device. In other cases, the establishment of preset rpm in the device is relied on and a real measurement is not made on them or there is no way to make such a measurement in some devices, for example, in pneumatic stirrers.
In the industry of paints, more especially in automotive paints, a stirring control at certain rpm is required for the correct homogenization of solvents and solids which include pigments (color) and other particles such as flakes or beads which provide desired finishings. If the homogenization of these components is not done properly some parts of the paint will have different proportions of said components and therefore irregular finishings are obtained when the paint is applied on different areas of the object to be painted.
Therefore, the present invention is directed to a mechanical assembly which permits the measurement of rpm in devices including rotating shafts, which is adaptable to any type of rotating shaft, in particular, to rotating shafts in pneumatic devices and which does not depend on easily-damaged electronic parts as well as a simplicity for its application, repairing and for an accurate measurement of rpm in said rotating shafts and other desirable features which will be evident from the following detailed description of the invention.
An object of this invention is to provide a mechanical assembly for the measurement of rpm on shafts of devices having them.
Another object of this invention is to provide a mechanical assembly for the measurement of rpm on shafts of pneumatic devices, particularly stirrers or pneumatic stirring motors.
The attached Figures are incorporated and form part of the description in an illustrative manner and said Figures should not be considered as a limitation thereof.
This description refers, in a general way, to a mechanical assembly for measuring rpm on rotating shafts of devices having them, comprising a rpm measuring device which includes a rotating axis for the measurement, a support base which houses and keeps fixed thereto said rpm measuring device and which allows the passage of the rotating axis thereof, said support base being fixed to a casing which also allows the passage of said rotating axis. A first rotation drive pulley is fixed to the rotating axis of the rpm measuring device. The device to which the rpm measurement is to be conducted is evidently a device including a rotating shaft, in which a second rotation drive pulley is fixed to the rotating shaft of the device. The first and second drive pulleys are operatively connected to each other by a belt and both pulleys are aligned in the same level, i.e., aligned with each other. The casing is attached to the device to be measured, allowing the rotating shaft of said device to pass therethrough, so that it maintains a constant distance between the rotating shaft of the device and the rotating axis of the rpm measuring device to prevent the belt slackening and slipping off the pulleys. The first and second pulleys and the belt are located inside the casing. When the rotating shaft device is driven the rotating shaft drives a torque to the second pulley which in turn drives said torque to the first pulley via the belt and to the rotating axis of the rpm measuring device on which the measurement is made.
In one embodiment applicable in any other embodiment of the present invention, the rpm measuring device is an odometer widely known in the prior art so that its constitution and description should be understood by reference.
In one embodiment applicable in any other embodiment of this invention, the pulleys present a ratio of first pulley to second pulley diameters of 1:1. However other ratios may be used, provided that the necessary adjustments and considerations are made in the rpm measuring device. For example, if the range of measurement of the rpm measuring device falls outside of the known rpm range of the device, it is possible to use a pulley diameter ratio other than 1:1, i.e., 1:>1 or vice versa as required and the user will make the calculations to obtain the rpm value corresponding to such a pulley diameters ratio.
In one embodiment applicable to any other embodiment of the present invention, the pulleys are toothed pulleys in which case the belt should also be toothed.
The assembly of this invention may additionally have at least a belt tensioning element known in the prior art, for example, tension rollers, in order to keep the tension between the two pulleys and the belt. Said at least one belt tensioning element may be attached to the casing for tensioning close to the first pulley or to the second pulley, or close to both pulleys. Of course, said at least one tensioning element is located inside the casing.
The device including a rotating shaft to which the rpm measurement is to be conducted, as mentioned above, can be any device that has a rotating shaft to perform its purpose. Some enunciative but not limiting examples of the device are pneumatic or electric stirrers for fluids, any type of motor, among others. Preferably, the mechanical assembly of the present invention is susceptible of being attached to the device including a rotating shaft and to a working surface wherein the device conducts its purpose as it is explained below in one embodiment of the present invention and an example thereof will be shown in the embodiment corresponding to
In one embodiment applicable in any other embodiment of the present invention, the mechanical assembly of the present invention further includes a connecting means capable of being attached to said device including a rotating shaft to the casing and to the working surface without interrupting the rotation of the rotating shaft of the device, the second pulley and the belt passage. Said connecting means may include different configurations useful for the present invention. In an illustrative but not limiting example, the connecting means is a jacket comprising open parts, recesses or windows allowing freely the rotation of the rotating shaft of the device, the second pulley and the passage of the belt through said jacket, an attaching section to the device including rotating shaft and a connecting section capable of being attached to the casing and to a working surface. The fastening and connecting sections may have configurations known in the art.
In order to avoid vibrations and cavitations between the casing and the components associated and/or housed therein of the mechanical assembly of the present invention and the device including a rotating shaft and the working surface when said device with rotating shaft is operatively active, in an embodiment applicable to any other embodiment of the present invention, the mechanical assembly may further include at least one seat support base outside of the casing which is arranged in different positions thereof and/or directly or indirectly associated to said device including rotating shaft.
In a preferred embodiment, wherein its technical features are applicable in any other embodiment of the present invention and referring to at least one of
As will be seen, the rotating shaft 205 of the pneumatic motor 200 is also attached to a stirring rod 215 via bushing 145 with bores 146 and idlers (not shown).
Another advantage of the mechanical assembly of the present invention, in addition to those indicated above and those which will be evident from this description in any of its modalities, is that it is possible to monitoring the rpm values of a rotating shaft in a device including a rotating shaft without electrical and/or electronic elements which could generate sparks being very dangerous in cases where in volatile and flammable liquids take part in a process wherein such a device is required, since the risk of explosion is extremely high. An example of this is the mixing and homogenization of automotive paints, wherein flammable solvents are used for the preparation of such paints. Since the mechanical assembly of the present invention lacks of such electrical and/or electronic elements, the risk indicated for determining the rpm value of the device is not present.
It is clearly evident that the mechanical assembly of the present invention can be used in several industries, for example, in the varnish, food, environmental water restoration, chemical and biological processes wherein CSTR type or agitated batch type reactors are used, among others which will be clearly evident to a technician in the art.
Likewise, the mechanical rpm measuring assembly of the present invention complies with characteristics of explosion proof equipment, in accordance with the ATEX Directive arising and applicable in the European Union, as well as it is susceptible of obtaining the CE (Conformité Européenne) marking and the symbol “EX” to identify it as approved under the ATEX Directive.
While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, combinations, and equivalents will occur to those with knowledge and experience in the art. The invention is described in detail with reference to some particular embodiments or configurations, but it should be understood that various other modifications can be made, as well as combinations thereof, and still be within the spirit and scope of the invention. It is to be understood, therefore, that the following claims are intended to cover all modifications and changes falling within the true spirit of the invention.
Number | Date | Country | Kind |
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MX/U/2020/000136 | Jul 2020 | MX | national |
Filing Document | Filing Date | Country | Kind |
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PCT/MX2021/050034 | 7/13/2021 | WO |