JP2004066014A - Device for sensing liquid level and underwater machine with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make easily detectable the ingression of water, etc., into a motor chamber and leakage of lubricating oil from a reduction gear chamber without pulling up an underwater machine from the water. <P>SOLUTION: A first float switch 71 which gives a liquid ingression detection signal when the liquid level of water, etc., ingressed into a motor chamber 13b reaches a prescribed height or above is disposed in the motor chamber 13b. A second float switch 72 which gives a liquid leakage detection signal when the lubricating oil level in a reduction gear chamber 15a reaches a prescribed height or below is disposed in the reduction gear chamber 15a in such a way that the floats of the first and second float switches 71, 72 move in opposite directions according to on-off actions of the switches. The contacts of the switches 71, 72 are connected in series, and when any of the switches 71, 72 operates, the detection signal is transmitted above to the ground. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a device for detecting intrusion of water or oil into a motor room, leakage of lubricating oil stored in a reduction gear room, and the like, and an underwater mechanical aeration and agitation device equipped with the device. Pertaining to the machine. In particular, the present invention relates to a countermeasure for easily detecting the intrusion or leakage.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as one of underwater machines used in a state of being immersed in water, for example, an underwater mechanical aeration and stirring device disclosed in Japanese Patent Application Laid-Open No. 2000-263082 is known. This type of aeration and stirring device is used in a state where it is submerged in a reaction tank of a sewage treatment system. Further, the aeration stirring device includes a submersible motor inside, and the output of the submersible motor is transmitted to the impeller via an output shaft after being reduced by a speed reducer. The rotation of the impeller stirs the inside of the reaction tank, thereby improving the purification efficiency of wastewater.
[0003]
By the way, since such an aeration and stirring device is used in a state where it is submerged in water for a long period of time, there is a concern that water may enter the inside of the casing. When such water infiltrates, particularly when water invades into the motor room accommodating the underwater motor, the underwater motor may be broken. Further, a predetermined amount of lubricating oil is stored in the speed reducer chamber in order to smoothly perform the speed reduction operation of the speed reducer and prevent wear of each gear. However, when the lubricating oil leaks out of the reduction gear room due to, for example, aging of the shaft seal portion, poor lubrication occurs, each gear is worn, and the life of the reduction gear can be extended. You will not be able to.
[0004]
In the past, work has been conducted to periodically raise the aeration and stirring device above the water to check whether water or the like has entered the motor room or the leakage of lubricating oil from the reduction gear room has occurred. I was going.
[0005]
[Problems to be solved by the invention]
However, in the above-mentioned inspection work, it is necessary to pull up the aeration and stirring device above the water every time, and it takes a long time for the inspection work. During this inspection work, the inside of the reaction tank cannot be agitated.Therefore, frequent inspection work is performed to find out early the intrusion of water etc. into the motor room and the leakage of lubricating oil from the reduction gear room. In such a case, the time for stirring the inside of the reaction tank by the aeration and stirring device is greatly reduced. As a result, a problem that the purification efficiency of the sewage cannot be sufficiently increased is caused. In addition, since this type of apparatus is relatively heavy, the work of pulling it up on the water is extremely complicated.
[0006]
The present invention has been made in view of such a point, and an object thereof is to easily detect the intrusion of the water or the like and the occurrence of leakage of the lubricating oil without lifting the underwater machine above the water. Is to do so.
[0007]
[Means for Solving the Problems]
-Summary of the invention-
In order to achieve the above object, the present invention provides a float switch for detecting liquid intrusion (for example, water intrusion into a motor room) into a closed space, and a liquid leak from a liquid storage room (for example, a reduction gear room). And a float switch for detecting lubricating oil leakage from the water) to constitute a liquid level detection device. When any of the float switches is activated, the detection signal can be transmitted to the ground or toward the water. I have to.
[0008]
-Solution-
Specifically, the liquid level is detected by detecting liquid intrusion into a closed space formed inside an underwater machine installed in water and liquid leakage from a liquid reservoir formed inside the underwater machine. It is assumed that the liquid level detecting device recognizes the information. A first float switch that is provided in the closed space and that issues a liquid intrusion detection signal when the liquid level of the liquid that has entered the closed space reaches a predetermined height or higher; A second float switch that is provided in the liquid reservoir chamber and that issues a liquid leakage detection signal when the liquid level in the liquid reservoir chamber reaches a predetermined height or less, and directs the detection signal generated by each float switch to the surface of the water or the ground. And transmission means for transmitting the data.
[0009]
According to this specific matter, the liquid enters the enclosed space (for example, water enters the motor chamber), and when the liquid level reaches a predetermined height or more, the first float switch issues a liquid intrusion detection signal. On the other hand, when the liquid in the liquid storage chamber leaks out (for example, when the lubricating oil leaks out of the reduction gear chamber) and the liquid level reaches a predetermined height or less, the second float switch issues a liquid leak detection signal. . These signals are transmitted to the water or the ground by the transmitting means. For example, in the case where a receiving means capable of receiving these signals is provided on the water or on the ground, the signal receiving operation of the receiving means makes it possible to confirm liquid intrusion into the closed space or leakage of the liquid from the liquid storage chamber. . That is, these can be easily and early confirmed without raising the underwater machine above the water.
[0010]
As a specific configuration of the installation state of each float switch, a float switch having the same configuration is adopted as the first float switch and the second float switch, and these are arranged so that the operation directions with respect to the movement of the float are opposite to each other. I do. Then, the float rises with the infiltration of the liquid into the closed space, and the first float switch transmits a liquid intrusion detection signal when the rising position reaches a predetermined position. Further, the float descends due to liquid leakage from the liquid reservoir chamber, and the second float switch transmits a liquid leakage detection signal when the lowered position reaches a predetermined position. As described above, since the same switch is used as each float switch, the types of components of the underwater machine can be reduced.
[0011]
Further, as a specific configuration of each float switch, a contact of each float switch is formed by a b contact. When the liquid level of the liquid that has entered the sealed space reaches a predetermined height or higher, the contact point of the first float switch is opened, and when the liquid level in the liquid storage chamber reaches a predetermined height or lower. The contacts of the second float switch are opened, and these contacts are connected in series to constitute a liquid level detection circuit. As a result, despite the provision of two float switches, one circuit can be used as both a circuit for detecting liquid intrusion and a circuit for detecting liquid leakage, thereby avoiding complication of the circuit configuration. be able to. The same effect can be obtained even if the contacts of the floats are a contacts and these circuits are connected in parallel.
[0012]
As a specific example of the detection target, the closed space is a motor room, and the first float switch detects the intrusion of water or oil into the motor room. On the other hand, the liquid storage chamber is a reduction gear chamber, and the second float switch detects leakage of lubricating oil from the reduction gear chamber. With this configuration, it is possible to prevent a failure of the motor due to intrusion of water or oil into the motor chamber, and it is possible to prevent wear of gears due to insufficient lubricating oil in the reduction gear chamber.
[0013]
In addition, the present invention is also applicable to an underwater machine incorporating the liquid level detection device of each of the above-described configurations, and an aeration and stirring device installed in a reaction tank for performing biological reaction treatment of sewage with activated sludge. It is a category of technical thought.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case will be described in which the present invention is applied to an underwater mechanical aeration and agitation device employed in a sewage treatment system as an underwater machine. Further, a case will be described in which a liquid level detection device is configured as a device for detecting intrusion of water or oil into the motor chamber, leakage of lubricating oil stored in the reduction gear chamber, and the like.
[0015]
-Description of the overall configuration of the aeration and stirring device-
FIG. 1 is a front view showing the aeration and stirring device according to the present embodiment, and FIG. 2 is a cross-sectional view showing the internal configuration thereof. This aeration and agitation device includes a rotation drive mechanism 10 having an axial center extending in a vertical direction, and an impeller 20 (see FIG. 2) attached to a lower side of the rotation drive mechanism 10 so as to be rotated by the rotation drive mechanism 10. ing. The impeller 20 is arranged in a substantially cylindrical pump casing 30. Above the pump casing 30, a short cylindrical discharge casing 40 provided with a plurality of discharge ports 41 extending in the radial direction is attached.
[0016]
As shown in FIG. 2, the rotation drive mechanism 10 is disposed in a discharge casing 40 by being attached to a submersible motor 11 having an axis extending in a vertical direction and an output shaft extending below the submersible motor 11. And a speed reducer 12. The output shaft of the speed reducer 12 passes through the center of the discharge casing 40 and reaches the inside of the pump casing 30. The speed reducer 12 of the rotary drive mechanism 10 is supported by the discharge casing 40. The impeller 20 is attached to an output shaft of the speed reducer 12 located in the pump casing 30.
[0017]
The impeller 20 has a cylindrical boss 21 attached to the output shaft of the speed reducer 12. The impeller 20 is driven by the underwater motor 11 of the rotary drive mechanism 10 to drive the boss 21 through the speed reducer 12. 21 is rotated. Impellers 22 are provided on the peripheral surface of the boss 21 at equal intervals in the circumferential direction. Each impeller 22 has a large pitch angle and extends radially from the peripheral surface of the boss 21 so that a strong upward water flow is generated by the rotation of the boss 21.
[0018]
The pump casing 30 surrounding the impeller 20 has a substantially cylindrical casing body 31 whose diameter is gradually increased downward, and the upper and lower surfaces of the casing body 31 are open. The outer peripheral surface of the casing body 31 is reinforced by a plurality of vertically extending reinforcing ribs 33 arranged at equal intervals in the circumferential direction. On the lower surface of the casing main body 31, for example, three legs 32 extending downward are arranged at equal intervals in the circumferential direction, and the lower surface of the casing main body 31 is water-treated by each leg 32. An appropriate distance from the bottom of the reaction tank is maintained.
[0019]
When the impeller 20 arranged in the casing main body 31 of the pump casing 30 rotates, water is sucked into the inside from the open lower surface of the casing main body 31 by each impeller 22, and passes through the inside of the casing main body 31 upward. Swept away.
[0020]
An air supply pipe 50 is inserted through a lower axial center of the boss 21 of the impeller 20 disposed in the pump casing 30. A plurality of air discharge ports 21b are arranged on the upper peripheral surface of the boss portion 21 at equal intervals in the circumferential direction, and air supplied from the air supply pipe 50 passes through each air discharge port 21b. Is discharged into the casing body 31 of the pump casing 30.
[0021]
FIG. 3 is a partially cutaway plan view of a discharge casing 40 disposed above the pump casing 30, and FIG. 4 is a cross-sectional view taken along line AA of FIG. As shown in FIG. 4, the discharge casing 40 is provided with an annular lower guide plate 42 having an opening 42a at the center thereof, and at an appropriate interval above the lower guide plate 42. And an upper guide plate 43.
[0022]
The lower guide plate 42 is in a state of being gradually inclined downward at an angle of about 5 to 40 degrees around the opening 42 a provided in the axis portion as it goes outward. The inner peripheral edge around the opening 42a is curved in an arc shape with a small curvature downward, and a flange portion 44 extending horizontally outward is provided at the lower end portion over the entire periphery. Has been. The flange portion 44 is mounted on the entire upper surface of the casing body 31 of the pump casing 30 and is bolted to the upper surface of the casing body 31 of the pump casing 30.
[0023]
The upper guide plate 43 is formed in an annular shape having a through hole 43a at the center thereof, and is disposed above the lower guide plate 42 at a predetermined interval and substantially in parallel. The inner peripheral portion of the upper guide plate 43 around the through hole 43a is gently curved in an arc shape so as to extend downward, and its inner peripheral edge is concentric with the opening 42a of the lower guide plate 42. Located in state.
[0024]
As shown in FIG. 3, the upper guide plate 43 is divided into six equal parts by radially extending partition members 46 at six equally spaced positions in the circumferential direction. The number of divisions may be changed as appropriate according to the model or the like. Each partition member 46 has a pair of partition portions 46a extending substantially in the radial direction between the lower guide plate 42 and the upper guide plate 43. Each partition 46 a is configured to be bent downward integrally with the upper guide plate 43, and the lower edge is in contact with the upper surface of the lower guide plate 42.
[0025]
The inner peripheral portion of the partition member 46 is a connecting portion 46b that connects the inner peripheral portions of the respective partition portions 46a. The connecting portion 46b is curved in an arc shape with a relatively large curvature so as to protrude toward the inner peripheral side, and is inclined at about 30 to 60 degrees so as to be located upward as it approaches the inner peripheral side. It is in a state.
[0026]
A guide groove 45 that opens upward and outward and extends in the radial direction is formed between the partition walls 46a.
[0027]
Portions of each partition member 46 that are surrounded by the partition 46a, the lower guide plate 42, and the upper guide plate 43 are discharge ports 41 of water that flows upward by the impeller 20, respectively.
[0028]
The partition walls 46a are successively opened so as to be separated from each other as they become closer to the outer peripheral side. Therefore, the guide grooves 45 formed between the partition walls 46a are formed on the outer periphery of the lower guide plate 42. The dimension in the width direction increases toward the side. As a result, in each of the discharge ports 41 defined by one of the partition walls 46a of the adjacent partition members 46, the middle of the radial direction is expanded in the circumferential direction, and the respective discharge-side ends are positioned on the outer peripheral side. As it gradually becomes smaller, it gradually narrows in the circumferential direction.
[0029]
A lower end edge of a truncated conical stay 48 is supported by a curved portion on the inner peripheral side of the upper guide plate 43. The stay 48 is concentric with the through hole 43a of the upper guide plate 43, and has a peripheral surface inclined at about 45 degrees so as to be continuous with the connecting portion 46b of each partition member 46. The upper and lower surfaces of the stay 48 are open, and the underwater motor 11 in the rotary drive mechanism 10 is connected to the speed reducer 12 in a vertical state with the output shaft facing downward. The speed reducer 12 to which the underwater motor 11 is connected is located in the stay 48 and the through hole 43 a of the upper guide plate 43.
[0030]
Hook members 47 are attached to the upper surface of the upper guide plate 43 located on one side of every other guide groove 45 among all the guide grooves 45. As shown in FIGS. 1 and 2, each hook member 47 is configured such that a lower end portion of a hanging member 60 is locked, and a wire rope or the like is locked to the hanging member 60 so that the underwater aeration is performed. The whole stirring device is lowered into the inside of the water treatment reaction tank and installed on the bottom thereof.
[0031]
When the underwater aeration and stirring device having such a configuration is installed on the bottom surface of the water treatment reaction tank, the underwater motor 11 of the rotary drive mechanism 10 is driven. Thereby, the impeller 20 arranged in the casing body 31 of the pump casing 30 is rotated. By the rotation of the impeller 20, water is sucked through the bottom surface into the casing body 31 of the pump casing 30, and flows upward in the casing body 31.
[0032]
At this time, air supplied from the air supply pipe 50 is discharged from each air discharge port 21b provided on the upper peripheral surface of the boss portion 21. Then, the air discharged from each of the air discharge ports 21b is diffused and mixed into the water flowing upward through the casing body 31 of the pump casing 30. Since each of the air discharge ports 21b rotates coaxially with the impeller 22, the air discharged from each of the air discharge ports 21b is finely sheared by the rotation action to form fine bubbles, and oxygen in the bubbles is efficiently removed from the water. Dissolved in
[0033]
In this way, the water in which the fine bubbles are diffused flows upward in the casing body 31 of the pump casing 30 and is introduced between the lower guide plate 42 and the upper guide plate 43 of the discharge casing 40, It is bent outward in the radial direction by the guide plate 43, and is ejected obliquely downward in the radial direction from all the discharge ports 41 partitioned by the partition members 46.
[0034]
Since the water discharged from all the discharge ports 41 flows along the bottom of the water treatment reaction tank, the bottom of the water treatment reaction tank is reliably stirred. In addition, since the water discharged from the discharge port 41 is efficiently mixed with air, the bottom of the water treatment reaction tank is efficiently and reliably aerated.
[0035]
-Explanation of liquid level detection device-
Next, a liquid level detecting device which is a feature of the present embodiment will be described. FIG. 5 is a sectional view showing the internal configuration of the underwater motor 11 and the speed reducer 12. As shown in FIG. 5, the underwater motor 11 is configured such that a motor main body 14 is accommodated in a motor casing 13 in which the inside is formed as a closed space. The output shaft 14a extending downward from the motor body 14 penetrates through the bottom plate 13a of the motor casing 13 and is connected to the lower reducer 12.
[0036]
On the other hand, the speed reducer 12 is provided with a plurality of gears 16 in a speed reducer casing 15 formed as a liquid storage chamber (space in which lubricating oil is stored), and a rotational driving force received from an output shaft 14 a of the motor body 14. Is transmitted to the impeller 22 through the boss 21 of the impeller 20. A predetermined amount of lubricating oil O is stored in the reduction gear casing 15, and the lubrication of the lubricating oil O prevents wear of each gear 16.
[0037]
The liquid level detection device 70 includes float switches 71 and 72 disposed inside the motor casing 13 and inside the reduction gear casing 15, respectively. Hereinafter, an arrangement state of each of the float switches 71 and 72 will be described.
[0038]
The float switch 71 provided inside the motor casing 13 (motor chamber 13b) is a first float switch for detecting entry of oil or water into the inside of the motor chamber 13b. As shown in FIG. 5, an oil pocket 13c in which a bottom plate 13a is partially recessed downward is formed at the bottom of the motor chamber 13b. That is, when oil or water enters the interior of the motor chamber 13b, the oil or water is accumulated in the oil pocket 13c. The first float switch 71 is located inside the oil pocket 13c. With this configuration, when oil or water enters the motor chamber 13b and accumulates in the oil pocket 13c, the position of the float 71a of the first float switch 71 moves upward with an increase in the liquid level, When the float 71a moves to a predetermined position, the first float switch 71 transmits a liquid intrusion detection signal.
[0039]
On the other hand, the float switch 72 provided inside the reduction gear casing 15 (the reduction gear chamber 15a) is a second float switch for detecting leakage of the lubricating oil O from the reduction gear chamber 15a. As shown in FIG. 5, the second float switch 72 is attached to a top plate 13a (also serving as a bottom plate of the motor casing 13) of the reduction gear chamber 15a. With this configuration, due to the leakage of the lubricating oil O from the reduction gear chamber 15a, the position of the float 72a of the second float switch 72 moves downward with the lowering of the oil level, and the float 72a moves to a predetermined position. At this time, the second float switch 72 transmits a liquid leakage detection signal. The mounting position of the second float switch 72 is set on the lower surface of the oil pocket 13c. This makes it possible to position the second float switch 72 near the bottom surface of the reduction gear casing 15 while keeping the length of the support shaft 72b supporting the second float switch 72 as short as possible. .
[0040]
Further, the first float switch 71 and the second float switch 72 are constituted by float switches having the same configuration, and are arranged so that the operation directions with respect to the movement of the float are opposite to each other. That is, with such an arrangement, the first float switch 71 operates when the liquid level rises above a predetermined height, and conversely, the second float switch 72 operates when the liquid level falls below a predetermined height. It is supposed to. As described above, since the same float switches 71 and 72 are used, the types of components of the aeration and stirring device can be reduced.
[0041]
Each of the float switches 71 and 72 is connected to a signal line (not shown) as transmission means, and the detection signal is output to this signal line. The signal line extends toward the ground, and transmits a liquid intrusion detection signal and a liquid leak detection signal to a receiver installed on the ground. For example, the receiving device is provided with an alarm buzzer, and when any of the above detection signals is received, the alarm buzzer is activated to issue an alarm to a system administrator.
[0042]
-Description of underwater motor drive circuit-
Next, a description will be given of a submersible motor drive circuit of the aeration and stirring device according to the present embodiment. FIG. 6 shows this drive circuit, and FIG. 7 shows a relay circuit. As shown in these figures, the underwater motor 11 is driven to rotate by being supplied with three-phase alternating currents (R, S, T). 82 and an overload detector 83 provided with an ammeter are provided respectively.
[0043]
Further, between a part (k, l) of each output line (k to n) of the underwater motor 11, the contacts A1, A3 of the float switches 71, 72 are connected in series, and Is provided between the output lines (m, n). The contacts A1 and A3 of the float switches 71 and 72 are b contacts, and the contact A1 of the first float switch 71 is opened when the liquid level of the liquid entering the motor chamber 13b reaches a predetermined height or more. At the same time, the contact A2 of the second float switch 72 is opened when the liquid level in the reduction gear chamber 15a reaches a predetermined height or less.
[0044]
The relay circuit will be described. An operation cutoff line L3, a liquid level detection line L4 as a liquid level detection circuit, an overheat detection line L5, an electric leakage detection line L6, an overload detection line L7 are provided between a pair of power buses L1 and L2. An operation start line L8 and an operation / stop switching line L9 are provided.
[0045]
The operation cutoff line L3 is energized when the electromagnetic relays Ax1, Ax2, ELBX, 49x, 49x, and the plurality of switches Ax1 to CR provided on the other lines L4 to L8 are switched and any one of these switches is turned off. Is released. That is, when the excitation of any of the electromagnetic relays Ax1 to CR of the lines L4 to L8 is released, the corresponding switches Ax1 to CR are turned off, and the excitation of the electromagnetic contactor 52 is released accordingly. The power supply cutoff switch 82 is turned off to forcibly stop the underwater motor 11.
[0046]
The liquid level detection line L4 includes the contacts A1 and A3 of the float switches 71 and 72 connected in series as described above, and the electromagnetic relay Ax1 that releases the excitation when any of the contacts A1 and A3 is turned off. I have. That is, when a detection signal is output from one of the float switches 71 and 72 having the b contact, the excitation of the electromagnetic relay Ax1 is released and the switch Ax1 of the operation cutoff line L3 is turned off. It has become.
[0047]
The overheat detection line L5 is provided with the overheat detection switch A2 that is turned off when the underwater motor 11 is abnormally overheated, and an electromagnetic relay Ax2 that is turned off when the overheat detection switch A2 is turned off. That is, when the underwater motor 11 abnormally overheats, the excitation of the electromagnetic relay Ax2 is released and the switch Ax2 of the operation cutoff line L3 is turned off.
[0048]
The earth leakage detection line L6 includes an earth leakage detection switch ELB that turns off when the earth leakage is detected by the earth leakage detection unit 81, and an electromagnetic relay ELBX that cancels excitation when the earth leakage detection switch ELB turns off. That is, when a leakage occurs in the underwater motor 11, the excitation of the electromagnetic relay ELBX is released and the switch ELBX of the operation cutoff line L3 is turned off.
[0049]
The overload detection line L7 includes an overload detection switch 49 that is turned off when the overload of the underwater motor 11 is detected by the overload detection unit 83, and the excitation is released when the overload detection switch 49 is turned off. An electromagnetic relay 49x is provided. That is, when an overload of the underwater motor 11 occurs, the overload detection switch 49 is turned off, and the switch 49X of the operation cutoff line L3 is turned off.
[0050]
The run / stop switching line L9 includes a main switch S that can be turned on / off by manual operation, and an electromagnetic relay KP that is excited when the main switch S is turned on. On the other hand, the operation start line L8 includes an operation switch KP that is turned on when the electromagnetic relay KP is excited, and an electromagnetic relay CR that is excited when the operation switch KP is turned on. That is, as the main switch S is turned on, the electromagnetic relay CR of the operation start line L8 is excited, and thereby the switch CR of the operation cutoff line L3 is turned on.
[0051]
With the above configuration, in a state where the main switch S is turned on and the underwater motor 11 is driven, any one of the liquid level detection line L4, the overheat detection line L5, the leakage detection line L6, and the overload detection line L7. When the excitation of the electromagnetic relays Ax1 to CR is released, the corresponding switch on the operation cutoff line L3 is turned off and the underwater motor 11 is forcibly stopped. . In this case, a signal notifying that the underwater motor 11 has been forcibly stopped is transmitted to the receiving device on the ground via the signal line.
[0052]
As described above, in the aeration and agitation device according to the present embodiment, when water or the like enters the motor chamber 13b and the liquid level reaches a predetermined height or more, the first float switch 71 detects the liquid intrusion. On the other hand, when the signal is issued, the lubricating oil leaks from the inside of the speed reducer chamber 15a, and when the liquid level reaches a predetermined height or less, the second float switch 72 emits a liquid leakage detection signal. These signals are transmitted to the ground. For this reason, it is possible to easily and early confirm these infiltration and leakage without raising the aeration and stirring device above the water.
[0053]
Further, in the case of the present embodiment, the contact A1 of the first float switch 71 and the contact A3 of the second float switch 72, each having a contact b, are connected in series on the liquid level detection line L4. For this reason, although the two float switches 71 and 72 are provided, one detection line can serve as both a circuit for detecting liquid intrusion and a circuit for detecting liquid leakage, and the circuit configuration is complicated. Can be avoided. The same effect can be obtained by connecting the contact A1 of the first float switch 71 and the contact A3 of the second float switch 72 to the a contact, and connecting these circuits in parallel.
[0054]
Furthermore, in this embodiment, since the second float switch 72 is attached to the bottom plate 13a of the motor casing 13, disassembly work during maintenance can be easily performed.
[0055]
(Modification)
Next, a modified example of the present invention will be described. This example is a modification of the underwater motor drive circuit, and other configurations are the same as those of the above-described embodiment. Therefore, here, only the differences between the underwater motor drive circuit and the above embodiment will be described.
[0056]
FIG. 8 is a circuit diagram showing the underwater motor drive circuit according to this example. As shown in this figure, in this example, one (n) of the signal lines (k to n) of the underwater motor 11 is used as an input common line, and the other signal lines are output lines (k to n). m), the contact A1 of the first float switch 71 is connected to the output line (k), the overheat detection switch A2 is connected to the output line (l), and the contact A3 of the second float switch 72 is connected to the output line (m). Are provided.
[0057]
According to this configuration, when the submersible motor 11 is forcibly stopped, by detecting output signals from the output lines (km), the cause of the forcible stop is that oil into the motor chamber 13b is caused. It is possible to determine whether it is water or water intrusion, abnormal overheating of the underwater motor 11, or leakage of the lubricating oil O from the reduction gear chamber 15a. Moreover, these determinations can be made without increasing the number of output lines as compared with the embodiment (FIG. 6).
[0058]
-Other embodiments-
In the above-described embodiment and the modified example, an aeration and agitation device is adopted as the underwater machine to detect intrusion of water or oil into the motor chamber 13b and leakage of the lubricating oil stored in the reduction gear chamber 15a. The case where a liquid level detecting device is configured as the device described above has been described. The present invention is not limited to this, and can be applied as an apparatus for detecting various liquid levels in various underwater machines (such as a submersible pump).
[0059]
Further, the arrangement positions of the float switches 71 and 72 are not limited to the positions described above, and the connection states of the contacts A1 and A3 of the float switches 71 and 72 are not limited to those described above.
[0060]
Further, the configuration is not limited to the case where the detection signal transmitted from each of the float switches 71 and 72 is transmitted to a receiving device installed on the ground, and a configuration may be adopted in which the detection signal is transmitted to a receiving device floating and installed on water. . Further, the method of transmission to the receiving means may be wired or wireless.
[0061]
【The invention's effect】
As described above, in the present invention, the float switch is installed in the closed space and the liquid storage chamber inside the underwater machine, and when any of the float switches detects that the liquid level has reached the predetermined position. Transmits the detection signal to the water or the ground. For this reason, these can be easily and early confirmed without raising the underwater machine above the water. As a result, the submersible machine can be submerged continuously until liquid infiltration or liquid leakage occurs, and it is not necessary to temporarily stop operation of the submersible machine as in the conventional inspection work .
[0062]
In addition, if the float switches have the same configuration and are arranged so that the operation directions for the movement of the floats are opposite to each other, the types of components of the underwater machine can be reduced. In addition, the manufacturing cost can be reduced.
[0063]
Further, when the contacts of the float switches of the b-contact are connected in series or the contacts of the float switches of the a-contact are connected in parallel to constitute a liquid level detection circuit, a circuit for detecting liquid intrusion is provided by one circuit. And a circuit for detecting a liquid leak can also be used, so that the complexity of the circuit configuration can be avoided, and the practicality of the underwater machine of the present invention can be improved.
[Brief description of the drawings]
FIG. 1 is a front view of an aeration stirring device according to an embodiment.
FIG. 2 is a cross-sectional view of the aeration and stirring device.
FIG. 3 is a plan view in which a part of a discharge casing is broken.
FIG. 4 is a sectional view taken along the line AA in FIG.
FIG. 5 is a sectional view showing an internal configuration of a submersible motor and a speed reducer.
FIG. 6 is a diagram showing a drive circuit of a submersible motor.
FIG. 7 is a diagram showing a relay circuit for driving a submersible motor.
FIG. 8 is a diagram corresponding to FIG. 6 in a modified example.
[Explanation of symbols]
13b Motor room (closed space)
15a Reduction gear room (liquid storage room)
70 Liquid level detector
71 1st float switch
72 Second float switch
71a, 72a float
A1, A3 contact
O Lubricating oil (liquid)

Claims (7)

A liquid that recognizes liquid infiltration into a closed space formed inside a submersible machine installed in water and liquid leakage from a liquid reservoir formed inside the submersible machine by detecting the liquid level. A surface detection device,
A first float switch that is provided in the closed space and that issues a liquid intrusion detection signal when the liquid level of the liquid that has entered the closed space has reached a predetermined height or more;
A second float switch that is provided in the liquid reservoir chamber and that issues a liquid leak detection signal when the liquid level in the liquid reservoir chamber reaches a predetermined height or less;
A transmission means for transmitting a detection signal generated by each of the float switches to the surface of water or toward the ground. The liquid level detecting device according to claim 1,
The first float switch and the second float switch are float switches having the same configuration, and are arranged so that the operation directions with respect to the movement of the float are opposite to each other.
The first float switch is configured to emit a liquid infiltration detection signal when the float rises with the infiltration of the liquid into the closed space and the rising position reaches a predetermined position.
The second float switch is configured to transmit a liquid leak detection signal when the float is lowered with a liquid leak from the liquid reservoir chamber and the lowered position reaches a predetermined position. Surface detection device. The liquid level detecting device according to claim 1 or 2,
The contact of each float switch is composed of a b contact,
The contact of the first float switch is opened when the liquid level of the liquid entering the closed space reaches a predetermined height or higher, and the second contact is opened when the liquid level in the liquid storage chamber reaches a predetermined height or lower. A liquid level detecting device, wherein contacts of a float switch are opened, and these contacts are connected in series to constitute a liquid level detecting circuit. The liquid level detecting device according to claim 1 or 2,
The contact of each float switch is composed of a contact,
The contact of the first float switch is closed when the liquid level of the liquid entering the closed space reaches a predetermined height or higher, and the second float switch is turned on when the liquid level in the liquid storage chamber reaches a predetermined height or lower. The liquid level detecting device is characterized in that these contacts are closed, and these contacts are connected in parallel to form a liquid level detecting circuit. The liquid level detecting device according to any one of claims 1 to 4,
The enclosed space is a motor room, and the first float switch detects intrusion of water or oil into the motor room,
A liquid level detecting device, wherein the liquid storage chamber is a reduction gear chamber, and the second float switch detects leakage of lubricating oil from the reduction gear chamber. An underwater machine comprising the liquid level detecting device according to any one of claims 1 to 5. The underwater machine according to claim 6,
An underwater machine configured as an aeration and stirring device installed in a reaction tank that performs biological reaction treatment of sewage with activated sludge.

Images