Automatic device to regulate the vacuum pressure varying the rotation speed of the vacuum pump electrically powered, through the frequency variation of the power supply

Abstract

An automatic device to regulate and maintain stable the vacuum pressure varying the rotation speed of a vacuum pump. The device controls frequency variation of the current that powers its operation motor. The device may be used in installations of machine oerdeñadoras de animales, fixed and portable and other vacuum operated equipment or installations.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field and Title of the Invention

[0002] The present invention relates to automatic devices to regulate and/or maintain stable the vacuum pressure varying the rotation speed of the vacuum pump/s electrically powered, through the controlled frequency variation of the current that powers its operation motor, to be used preferably in installations of machine oerdeñadoras de animales, fixed and portable and other equipments or installations vacuum operated.

[0003] 2. Technique and Problems to be Sold

[0004] Nowadays, in the majority of the equipments and installations, vacuum operated, the vacuum level regulation is made through automatic valves whose mechanism is activated by the vacuum of the installation itself. So as the vacuum storage in tanks, for the compensation of sporadic consumption that may occur, is highly inefficient, a capacity or vacuum flow over the required minimum operating pumps and their motors at full operation must be generated.

[0005] This surplus of capacity is compensated making the air come through the vacuum regulator valve up to, in the event a vacuum loss in the installation occurs, the said valve closes automatically said compensating entering up to the obtention of the stabilization in the vacuum level, after that it lets the outer air enter again.

[0006] Consecuently, this surplus in the vacuum generation, when only required to compensate sporadical loss, makes the motor pump group need greater energy consumption and provoke greater wearing out of the movable pieces, greater maintenance costs, greater noise levels, greater lubricants consumption, all of them in detriment of the installation.

[0007] For the purposes of a better understanding of the object and scope of this invention, the technique actual in relation to the referred automatic valves above mentioned is hereafter stated, through a brief description of their construction and functioning through the drawings (FIG. 1 and 2) that are purely informative regarding the FIGS. 3, 4 and 5 concretely referred to the device object of the present invention.

[0008] FIG. 1 shows the functioning of a vacuum regulator servo assisted, automatic, pneumatic, conventional, one of them object of the present invention that acts regulating the vacuum flow generated excessively by the vacuum pump.

[0009] The sensor device a, in this case mounted on the superior part of the regulator body—sometimes it can be separated—has a chamber 1 connected to vacuum system b. by the duct 2 in charge of the detention of the vacuum variations of it. A compression spring 3, that according to the tension registered by an adjustment nut 3′, under a lid 4, determines the level of work of the sensor valve and thus the level maintained in the entire system b.

[0010] This sensor device a has a diaphragm 5 that with the spring mechanism acts on an obturator 6 that controls the opening of a hole 7 of atmospheric air entering, according to the regulation defined by the adjustment level of said spring, to a control chamber 1′ complementary of said chamber 1, from where, in this arrangement, the air surplus that the pump sucks when operating at full operation is controlled, and where a calibrated hole 1″ of outer air entering from the said chamber to the system.

[0011] One part of this complementary chamber 1′ is delimited by a diaphragm 8 joint by the outer edge to an obturator 9 which constitutes the principal valve c, where this obturator is operatively related to a cooperative base of a passage 10 outer air entering to the inlet 11 of the pump which has an adequate diameter for the generator flow of said pump.

[0012] This diaphragm 8 pushed by the spring 12, reacts to the vacuum pressure that the sensor mechanism regulates on the upper face inside chamber 1′, by a balance between air inlets and outlets (illustrated with+sign because in this case it shows a vacuum increase level) regarding to atmospheric pressure (indicated with small circles) that acts on external face of the diaphragm 8, as lifting obturator 9 of said main valve c opens the exterior air through adequate outlets of the regulator body wall that circles said main valve, enters the system through the said passage 10, to the inlet 11 of the pump, as shown with arrows in FIG. 1, and thus compensate the vacuum level in the system clearly produced when losses (leaks) disappeared.

[0013] FIG. 2 shows that the sensor mechanism detects a decrease in the vacuum level of system b due to leaks that allow the uncontrolled exterior air entering which automatically decreases vacuum pressure in chamber 1 of sensor mechanism a and thus in the complementary chamber 1′ that is to say, on the outer or inner phase of the diaphragm 8 and so the inner spring 12 overpasses atmospheric pressure (circles) and through obturator 9 of said diaphragm closes the passage 10 decreasing the air entering to the system, so as the pump compensates the vacuum level decrease of the system b, taking out the greatest airflow of the . . . (esta ultimo) pump or system b.

[0014] For a solution to the referred problem, electronic devices with electronic vacuum pressure sensors connected to una electronic device which process the electrical signal of the sensor and converts it in a control signal of electrical frequency converter are used. The frequency converter acts on the speed of electrical motor of vacuum pumps, so as varying the frequency or cycles per minute (HZ) the motor speed varies directly proportional.

[0015] In this case when the vacuum sensor shows a decrease of vacuum pressure level due to an air entering to the system, the electronic receives the information from the sensor, processes it and sends a control signal to a electrical frequency converter which accelerates the electrical engine of the vacuum pump, to compensate the system, maintaining the pressure leveled, then it desaccelerates to return to the former situation of the air entering to the system.

[0016] In this case the surplus of vacuum capacity generates continuously when necessary, thus producing energy saving, noise reduction and less components misuse, lubricant use and maintenance costs.

[0017] So economic and environmental benefits are obtained, but although these systems are efficient they are not spread due to the high costs of the sensor conjoint and electronic processor that command the frequency converter, even though these converters are serial manufactured devices and highly spread in the market at a reasonable cost.

[0018] The invention herein allows the replacement of this electronic conjoint of high cost by an automatic pneumatic device and purely electromechanical, that allows the speed control of a vacuum motor pump by means of a conventional frequency converter without using any electronic processor.

[0019] The invented device reduces the cost of the control system of the frequency converter and provides the improvements of the motor pump speed according the electronic system hereinabove described, regarding cost savings and environmental improvements.

[0020] Thus, this vacuum regulation system through the pump speed variation, can be spread in less acquisitive power, with the advantages described herein.

SUMMARY OF THE INVENTION

[0021] The object of the invention is achieved by means of the modification of a automatic pneumatic vacuum regulator valve, with same functioning principle of a conventional servo assisted vacuum regulator, where the direct exterior air inlet to the pump through the main valve is eliminated, and so this main valve with its connection to vacuum duct is also eliminated, adding a auxiliary detector device of the vacuum pressure variations in the interior of its regulator chamber, able to transform in a control electrical signal of a frequency converter intercalated in the supply electrical circuit to the motor, and all of them through a conjoint merely electromechanical integrated by common use components, very simple at a lower cost.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0022] For clarity and better understanding of the invention resulting from the application of the invented device, the present invention is illustrated by way of example according to some preferred embodiments, wherein:

[0023] FIGS. 1 and 2 show an scheme cross-section view of a vacuum servo assisted regulator of nowadays use, non object of the present invention, as exemplary, the first one shows the automatic reaction under a system pressure increase, whereas the second one shows the same reaction under a pressure decrease

[0024] FIG. 3 shows a schematic view of the automatic regulator vacuum invented, showing its connections to the frequency converter, which supplies the motor of the vacuum pump, all of them according to an exemplary embodiment.

[0025] FIGS. 4 and 5 show partial views of the invented device, shown as FIG. 3, according to other variations of the same embodiment, with different generators of the control signal of the converter, equivalent to the one provided in said example of the last figure.

[0026] In the different Figures the same signs indicate same or corresponding elements or components.

DESCRIPTION

[0027] The referred automatic vacuum regulator device, object of the present invention, as shown in FIG. 3 and as shown and described in FIGS. 1 and 2 and acts controlling and varying the electrical frequency as a means of instantly adjustment of the rotation speed of the motor and the vacuum pump to the necessary speed to maintain a constant vacuum level in the event of changes due to eventual air inlet to the system.

[0028] According to hereinabove mentioned and an exemplary embodiment the device, has the sensor mechanism applied on its upper edge and connected to vacuum system b but now only through duct 1. The diaphragm 8 of the main valve c is coupled to slider 13 of the potentiometer, variable resistance or rheostat d through arm 14.

[0029] The diaphragm 8 displacement by the effect of pressure variations in chamber 1, leaves aside the slider varying the resistance that the potentiometer interlaces through wires 15 in the control circuit of a frequency converter e, powered electrically and whose power outlet 16 is connected to electric motor f that propulses the vacuum pump 9.

[0030] The potentiometer d is usually powered by a low electrical current generated by the same frequency converter or by an external supply.

[0031] When an increase in the vacuum level of system b is detected by duct 2, the sensor mechanism a increases the vacuum pressure in chamber 1 and therefore in the outer or inner surface of the diaphragm 8 and the atmospheric pressure overpasses the spring 12 rising the arm 14 and activating the potentiometer b, varying the electrical resistance in the circuit of the control signal of the frequency converter e, which has been programmed to react accordingly to this control signal, and decreasing the cycles in the power of electrical motor f dessacelerating it and decreasing the rotation speed of the vacuum pump, whose flow decreases at a necessary one to matain the vacuum level registered by the regulator sensor through the spring 2 adjustment. The opposite situation is produced when the regulator mechanism causes the increase of the motor f cycles, accelerating the vacuum pump up to compensate a loss in the vacuum level detected in the system due to an air entering.

[0032] A possible variation of the system is shown in FIG. 4, where the said arm 14 and potentiometer d are replaced by a proximity electronic sensor h, that sends the signal to the frequency converter regarding the diaphragm 8 position, that is to say, the vacuum pressure in chamber 1′.

[0033] Other variety is shown in FIG. 5, where a transducer or pressure sensor i detects the vacuum level change in said control chamber 1′ of the diaphragm 8. It is worth mentioned that this variation also works without the said diaphragm 8, that can be replaced with a rigid lid to close chamber 1′, disregarding the use of the spring 9. At last, It is important to state that an applicable variation regarding any example hereinabove mentioned consists of having a calibrated hole 1″ and locating the obturator 6 of the sensor valve operated by the diaphragm, in relation to hole 7 placed in direct communication with the system through the duct 2.

[0034] While the nature and scope of the present invention have been described and determined, as well as the way of implementing it, we claim property and exclusive right as follows:

Claims

1. Automatic device to regulate vacuum pressure varying the rotation speed of the vacuum pump powered electrically by the frequency variation of the power supply, wherein it has a chamber connected to the vacuum system by a duct able to detect vacuum pressure variation through a calibrated hole of communication with the said chamber, one part of which is delimitated by a diaphragm subject to the pressure of a spring of regulable and joint tension to an obturator which controls a hole of air inlet to the system according to a regulation predetermined by the spring adjustment, including in operative relation with said chamber, an auxiliary device detector of the pressure variation in the inner of said chamber and provide them as a control electric signal of a frequency converter intercalated in the supply circuit of the Automatic device to regulate vacuum pressure electric motor of pump operation.

2. Automatic device to regulate vacuum pressure, according to

claim 1, wherein that said detector device has a second diaphragm incorporated as a part of the said chamber wall and connected exteriorly through a joint arm, rod, or the like, of transmission of it movement to the corresponding regulator of a potentiometer, variable resistance reostat, or the like, intercalado in the control circuit of the frequency converter.

3. Automatic device to regulate vacuum pressure, according to

claim 1, wherein that said detector device has a second diaphragm incorporated as a part of the said chamber wall and connected exteriorly to the monitoring of a proximity sensor able to detect diaphragm position changes and generate control electric signal of the frequency converter.

4. Automatic device to regulate vacuum pressure, according to

claim 1, wherein that said detector device has a sensor pressure transducer or the like applied on the said chamber, in direct operative relation with the interior of said chamber