CN110729086B

CN110729086B - Water resistor with adjustable resistance value

Info

Publication number: CN110729086B
Application number: CN201910791009.1A
Authority: CN
Inventors: 李海; 席志成; 程浩宇; 曾庆威; 马平安; 李相远
Original assignee: Wuhan Marine Machinery Plant Co Ltd
Current assignee: Wuhan Marine Machinery Plant Co Ltd
Priority date: 2019-08-26
Filing date: 2019-08-26
Publication date: 2021-10-08
Anticipated expiration: 2039-08-26
Also published as: CN110729086A

Abstract

The invention discloses a water resistor with an adjustable resistance value, and belongs to the field of water resistors. The water resistor includes: the resistance box, first polar plate, second polar plate and buoyancy control mechanism, buoyancy control mechanism includes two guide bars, the direction subassembly, buoyancy module and air supply, two guide bars respectively with direction subassembly slidable connection, the resistance box is airtight box, contain resistance liquid in the resistance box, first polar plate, the second polar plate, the direction subassembly, and buoyancy module all are located the resistance box, first polar plate is fixed in the bottom of box, be equipped with first terminal on the case lid, the bottom of box is relative with the case lid, first polar plate is connected with first terminal electricity, the second polar plate hangs directly over first polar plate, still be equipped with the second terminal on the case lid, the second polar plate is connected with the second terminal electricity, the second polar plate is installed in the direction subassembly, the first end of two guide bars is fixed in the bottom of box, the second end of two guide bars stretches out resistance liquid.

Description

Water resistor with adjustable resistance value

Technical Field

The invention relates to the field of water resistors, in particular to a water resistor with an adjustable resistance value.

Background

In the design of a high-power motor, a voltage reduction starting mode is required to reduce starting current. In consideration of the actual situation that the voltage and the current of the high-power motor are both ultrahigh indexes, the voltage reduction starting is usually realized by using a mode of a high-power motor series resistor, wherein the resistor can adopt a water resistor with low price. During the starting process of the motor, the distance between the polar plates at two ends of the water resistor, which are led out for electrification, needs to be controlled. For example, at the initial stage of starting the motor, the distance between the two polar plates is controlled to be farthest, and at the moment, the resistance value of the water resistor is the largest; and controlling the distance between the two polar plates to be gradually shortened along with the acceleration of the motor so as to reduce the resistance value of the water resistor, thereby realizing that the motor keeps smaller starting current in the starting process. At present, the distance between two polar plates is generally controlled by adopting a mechanical transmission method, for example, the polar plates are arranged on a rack, and then the rack is driven by adopting a small servo motor or a hydraulic motor to move to push the polar plates.

In the process of implementing the invention, the inventor finds that the prior art has at least the following problems: when a servo motor is adopted to drive the gear, a corresponding servo motor control system needs to be configured for the water resistor, and under the condition that the high-power motor is ultrahigh-voltage and high-power, the control system of the servo motor is interfered by electromagnetic waves emitted by the high-power motor to influence the work of the servo motor; when a hydraulic motor is adopted to drive the gear, a hydraulic pump station needs to be equipped, and the hydraulic pump station faces higher cost, subsequent maintenance and the like.

Disclosure of Invention

The embodiment of the invention provides a water resistor with an adjustable resistance value, which can adjust the distance between two polar plates of the water resistor under the driving of gas. The technical scheme is as follows:

the invention provides a water resistor with an adjustable resistance value, which comprises: a resistance box, a first polar plate, a second polar plate and a buoyancy control mechanism,

the buoyancy control mechanism comprises two guide rods, a guide assembly, a buoyancy assembly and an air source, the two guide rods are respectively connected with the guide assembly in a sliding way,

the resistance box is a closed box body, resistance liquid is contained in the resistance box, the first polar plate, the second polar plate, the guide assembly and the buoyancy assembly are all positioned in the resistance box,

the first polar plate is fixed at the bottom of the box body, the box cover is provided with a first binding post, the bottom of the box body is opposite to the box cover, the first polar plate is electrically connected with the first binding post,

the second polar plate hang in directly over the first polar plate, still be equipped with the second terminal on the case lid, the second polar plate with the second terminal electricity is connected, the second polar plate install in the direction subassembly, the first end of two guide bars is fixed in the bottom of box, the second end of two guide bars stretches out resistance liquid, buoyancy module is used for to direction subassembly provides buoyancy, the air supply be used for doing buoyancy module provides the gas.

Optionally, the guide assembly includes a support column, an installation arm and two guide arms, the guide arm is U-shaped, the support column is parallel to the two guide rods respectively, the first end of the installation arm and the first ends of the two guide arms are fixed to the two sides of the support column respectively, the second end of the installation arm is installed on the second polar plate, the open ends of the two guide arms are provided with guide rings respectively, the two guide arms are arranged on the two guide rods through the guide rings respectively, and the first ends of the guide arms are opposite to the open ends of the guide arms.

Optionally, the buoyancy assembly comprises a buoyancy ring, the buoyancy ring is sleeved on the support column, and the mounting arm and the two guide arms are located between the box cover and the buoyancy ring.

Optionally, a first electromagnetic valve is installed on the box cover, and the air source is communicated with the air tap of the buoyancy ring through the first electromagnetic valve.

Optionally, the buoyancy assembly further comprises a bubble generating disc, the bubble generating disc is of a cavity structure, a plurality of small holes are distributed on the surface, facing the box cover, of the bubble generating disc, and the bubble generating disc is communicated with the air source.

Optionally, a second electromagnetic valve is installed on the box cover, and the air source is communicated with the air tap of the bubble generation disc through the second electromagnetic valve.

Optionally, a fixing clip is mounted at the second end of the mounting arm, and the second pole plate clip is disposed on the fixing clip.

Optionally, the fixing clip includes a first clip arm and a second clip arm, the middle part of the first clip arm is hinged to the middle part of the second clip arm through a shaft, the first clip arm and the second clip arm are in an X shape, one end of the first clip arm and one end of the second clip arm which are located on the same side are provided with pre-tightening springs, and one end of the shaft is in threaded connection with the second end of the mounting arm.

Optionally, the first pole plate is electrically connected to the first terminal through a first cable, the second pole plate is electrically connected to the second terminal through a second cable, the first cable is a straight cable, and the second cable is a spiral cable.

Optionally, the air source is an air source.

The technical scheme provided by the embodiment of the invention has the following beneficial effects: on one hand, when the buoyancy is larger than the gravity borne by the guide assembly and the second polar plate and the buoyancy is gradually increased, the guide assembly rises along the guide rod after floating and drives the second polar plate to be far away from the first polar plate, the distance between the first polar plate and the second polar plate is increased, and the resistance value of water resistance is increased; when the buoyancy is smaller than the gravity borne by the current guide assembly and the second polar plate and the buoyancy is gradually reduced, the guide assembly descends along the guide rod and drives the second polar plate to approach the first polar plate, the distance between the first polar plate and the second polar plate is reduced, and the water resistance value is reduced; therefore, the distance between the two polar plates of the water resistor is adjusted under the driving of gas, the electromagnetic interference of a high-power motor on the electric control type polar plate motion mechanism can be effectively avoided, compared with a hydraulic control type polar plate motion mechanism, a pump station is not needed, and the maintenance cost and labor are reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a water resistor with an adjustable resistance value according to an embodiment of the present invention;

2-4 are assembly diagrams of a guide assembly and guide rod provided by an embodiment of the invention;

FIG. 5 is a cross-sectional view A-A of FIG. 2;

FIG. 6 is a schematic structural diagram of a water resistor with an adjustable resistance according to an embodiment of the present invention;

FIGS. 7-9 are schematic structural views of a bubble generation tray provided in accordance with an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a fixing clip according to an embodiment of the present invention.

In the drawing, a Q1 inflation inlet, a Q2 exhaust outlet, a 1 resistance box, 1a resistance liquid, a 2 first polar plate, a 3 second polar plate, a 4 guide rod, a 5 guide component, a 6 buoyancy component, a 7 first binding post, a 8 second binding post, a 9 support column, a 10 mounting arm, a 11 guide arm, a 12 guide ring, a 13 buoyancy ring, an air nozzle of a 14 buoyancy ring, a 15 first electromagnetic valve, a 16 bubble generation disc, an air nozzle of a 17 bubble generation disc, an 18 second electromagnetic valve, a 19 fixing clamp, a 20 first clamping arm, a 21 second clamping arm, a 22 pre-tightening spring, a 23 first cable, a 24 second cable and a 25 shaft.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of a water resistor with an adjustable resistance value according to an embodiment of the present invention, and the water resistor is suitable for a step-down start of a high-voltage and high-power motor. Referring to fig. 1, the adjustable-resistance water resistor includes: the device comprises a resistance box 1, a first polar plate 2, a second polar plate 3 and a buoyancy control mechanism. The buoyancy control mechanism comprises two guide rods 4, a guide assembly 5, a buoyancy assembly 6 and an air source. The two guide rods 4 are respectively connected with the guide assembly 5 in a sliding way.

The resistance box 1 comprises a box body and a box cover matched with the box body, resistance liquid is contained in the resistance box 1, and the first polar plate 2, the second polar plate 3, the guide assembly 5 and the buoyancy assembly 6 are all located in the resistance box 1.

The first polar plate 2 is fixed at the bottom of the box body, a first binding post 7 is arranged on a box cover of the resistance box 1, the bottom of the box body is opposite to the box cover, and the first polar plate 2 is electrically connected with the first binding post 7.

Second polar plate 3 hangs directly over first polar plate 2, still is equipped with second terminal 8 on the case lid of resistance box 1, and second polar plate 3 is connected with second terminal 8 electricity, and second polar plate 3 is installed in guide assembly 5, and the first end of two guide bars 4 is fixed in the bottom of box, and buoyancy assembly 6 is used for providing buoyancy to guide assembly 5, and the air supply is used for providing the gas for buoyancy assembly 6.

In the embodiment of the invention, the buoyancy component 6 provides buoyancy for the guide component 5, on one hand, when the buoyancy is larger than the gravity borne by the guide component 5 and the second polar plate 3 and the buoyancy is gradually increased, the guide component 5 rises along the guide rod 4 after floating, and simultaneously drives the second polar plate 3 to be far away from the first polar plate 2, at this time, the distance between the first polar plate 2 and the second polar plate 3 is increased, and the water resistance value is increased; when the buoyancy is smaller than the gravity borne by the current guide assembly 5 and the second polar plate 3 and the buoyancy is gradually reduced, the guide assembly 5 descends along the guide rod 4 and simultaneously drives the second polar plate 3 to approach the first polar plate 2, the distance between the first polar plate 2 and the second polar plate 3 is reduced, and the water resistance value is reduced; therefore, the distance between the two polar plates of the water resistor is adjusted under the driving of gas, the electromagnetic interference of a high-power motor on the electric control type polar plate motion mechanism can be effectively avoided, compared with a hydraulic control type polar plate motion mechanism, a pump station is not needed, and the maintenance cost and labor are reduced.

Illustratively, the cover of the resistance box 1 may be provided with a vent hole communicating with the outside air.

Fig. 2-4 are schematic views illustrating the assembly of the guide assembly 5 and the guide rod 4 according to the embodiment of the present invention. Referring to fig. 2-4, two guide rods 4 are installed in the water tank, and the guide rods 4 are fixed at the bottom of the tank side by side (one rod is blocked by the other rod in fig. 1) and vertically immersed in the resistance solution. Illustratively, the second ends of the two guide rods 4 may be in the resistance liquid, may extend out of the resistance liquid and be located below the case cover (see fig. 1), or may extend out of the case cover, which is not limited in the present embodiment.

Illustratively, the guide assembly 5 includes a support post 9, a mounting arm 10, and a two-piece guide arm 11. Guide arm 11 is the U type, and support column 9 is parallel respectively with two guide bar 4, and the first end of installation arm 10 and the first end of two guide arm 11 are fixed in the both sides of support column 9 respectively, and second polar plate 3 is installed to the second end of installation arm 10, and the open end of two guide arm 11 is equipped with guide ring 12 respectively, and two guide bar 4 are located through guide ring 12 cover respectively to two guide arm 11, and the first end of guide arm 11 is relative with the open end of guide arm 11.

The number of the guide rings 12 is 4, and the distance between the two guide rods 4 is the same as the distance between the two guide rings 12 of the same guide arm 11. When the buoyancy module 5 and the guide module 6 are put into a box for the first time, the four guide rings 12 are controlled to be penetrated through from the centers of the rings by the two guide rods 4 installed in the box, so that the guide module 5 is limited to move up and down along the guide rings 12, and the phenomena of deviation or rotation and the like cannot occur.

Embodiments of the present invention provide two example structures of a buoyancy module 6, including a first example structure and a second example structure.

The foregoing fig. 1 is a first example structure. In a first example configuration, the buoyancy module 6 comprises a buoyancy ring 13,

fig. 5 is a schematic structural diagram (also a cross-sectional view a-a in fig. 2) of the floating collar 13 according to an embodiment of the present invention. Referring to fig. 5, the buoyancy ring 13 is sleeved on the support column 9, and the mounting arm 10 and the two guide arms 11 are located between the box cover and the buoyancy ring 13. Accordingly, the resistor box 1 may or may not have a vent hole in the box cover.

Referring to fig. 5, the buoyancy ring 13 is fixedly connected to the supporting column 9 by bonding. After the buoyancy ring 13 is inflated in a still water state (a state without bubbles in water), the integral average density of the guide assembly 5 and the buoyancy assembly 6 is 0.8, and the guide assembly 5 and the buoyancy assembly 6 are guaranteed to float on the water surface.

Illustratively, referring to fig. 1, a first solenoid valve 15 is mounted on the box cover, and an air source is communicated with an air nozzle 14 of the buoyancy ring through the first solenoid valve 15.

Fig. 6 is a schematic structural diagram of a water resistor with an adjustable resistance value according to an embodiment of the present invention. Referring to figure 6, in a second example configuration, the buoyancy module 6 comprises the aforementioned buoyancy ring 13 and bubble-generating disc 16. The specific structure of the floating ring 13 is shown in fig. 5. Fig. 7 to 9 are schematic structural views of the bubble generation tray 16 according to the embodiment of the present invention. Referring to fig. 7-9, the bubble generating plate 16 is a hollow structure, a plurality of small holes are distributed on the surface of the bubble generating plate 16 facing the case cover, and the bubble generating plate 16 is communicated with an air source. Correspondingly, the box cover is provided with a vent hole. Wherein, the dish 16 is taken place to the bubble sets up with buoyancy circle 13 relatively, and first, second polar plate are located the bubble and take place one side of dish 16, and the bubble can upward movement after producing, can not influence horizontal waters, therefore the bubble is minimum to the waters influence between the polar plate, can neglect.

Preferably, hundreds of small holes with a hole diameter of 0.1mm are distributed on the surface of the bubble generation plate 16 facing the case cover at intervals of 10 mm. For example, the surface has 25 × 625 pores distributed at intervals of 10 mm. In this way, it is ensured that the bubble generation plate 16 generates uniform fine bubbles.

Illustratively, referring to fig. 6, a second solenoid valve 18 is mounted on the cover, and the air supply is communicated with the air bubble generating nozzle 17 through the second solenoid valve 18.

Note that, in the second example structure, the first solenoid valve 15 is an optional component, and the first solenoid valve 15 may not be necessarily provided. When the first electromagnetic valve 15 is not provided, the floating collar 13 is filled with gas in advance before installation.

And inflation hoses can be arranged between the first electromagnetic valve 15 and the air nozzle 14 of the buoyancy ring and between the second electromagnetic valve 18 and the air nozzle 17 for generating bubbles.

For example, the solenoid valve may be a 3-position, 3-way valve having three operating positions (inflation, deflation, shutoff) and three external connections (external inflation Q1, inflation of the buoyancy ring 13 or bubble generating disc 16, exhaust Q2). The valve can be set to any one of three operating positions by electric or manual operation. When the valve is in the inflation position, the exhaust port Q2 is closed, the external inflation port Q1 is communicated with the inflation port of the buoyancy ring 13 or the bubble generation disc 16, and an external air source inflates the buoyancy ring 13 or the bubble generation disc 16 through the valve; when the valve is at the stop position, the external charging port Q1, the buoyancy ring 13 or the charging port of the bubble generating disc 16 and the exhaust port Q2 are all closed, and the buoyancy ring 13 or the bubble generating disc 16 cannot be charged with air or leak air; when the valve is in the exhaust position, the outer inflation port Q1 is closed, the inflation port of the buoyancy ring 13 or bubble-generating disc 16 is in communication with the exhaust port Q2, and the buoyancy ring 13 or bubble-generating disc 16 is exhausted outwardly through the valve.

Illustratively, the second end of the mounting arm 10 is mounted with a retaining clip 19, and the second pole plate 3 is clamped to the retaining clip 19.

Fig. 10 is a schematic structural diagram of the fixing clip 19 according to the embodiment of the present invention. Illustratively, referring to fig. 10, the fixing clip 19 includes a first clip arm 20 and a second clip arm 21, a middle portion of the first clip arm 20 is hinged to a middle portion of the second clip arm 21 through a shaft 25, the first clip arm 20 and the second clip arm 21 are X-shaped, one end of the first clip arm 20 and one end of the second clip arm 21 on the same side are provided with a pre-tightening spring 22, and one end of the shaft 25 is in threaded connection with a second end of the mounting arm 10.

Illustratively, one end of the shaft 25 is externally threaded and correspondingly, the second end of the mounting arm 10 is internally threaded with a bore that mates with the external threads on the shaft 25. The second pole plate 3 is clamped at one end of the first clamping arm 20 and the second clamping arm 21, which is not provided with the pre-tightening spring 22. Due to the constraint of the pre-tensioned spring 22, the second pole plate 3 can be clamped by the first and

second clamp arms

20, 21. After being mounted by the fixing clip 19, the second electrode plate 3 is arranged to face the first electrode plate 2.

As shown in fig. 1, the water resistance device has two conductive plates (first and second plates) in common, and a conductive resistance liquid is provided between the plates, and when the resistance liquid is not changed, the electrical resistance value between the two plates is proportional to the linear distance between the plates, and the resistance is increased when the distance is about long. Illustratively, referring to fig. 1, the first pole plate 2 is electrically connected to the first terminal 7 through a first cable 23, the second pole plate 3 is electrically connected to the second terminal 8 through a second cable 24, the first cable 23 is a flat cable, and the second cable 24 is a spiral cable.

The first polar plate 2 is fixedly arranged at the bottom of the resistor box 1 and is immovable. The bottom of the resistance box is provided with a mounting seat (which can be made of nylon). The mount pad is cuboid shape, and the upper surface is provided with the screw thread blind hole. Bolts may be used to secure the first plate 2 to the threaded blind holes of the mounting block. The first cable 23 and the second cable 24 are watertight cables, respectively. The second plate 3 is fixed on the guide assembly 5 by a fixing clip 19 and moves along with the up-and-down movement of the guide assembly 5. The second cable 24 is pre-formed in a spiral coil shape to accommodate the up and down movement of the plates.

The air source is exemplarily an air source, and may be an external compressed air source, such as a mobile air compressor. The air source has the following advantages: 1) is convenient and cheap; 2) the water tank cover is provided with an air vent communicated with the outside air, and the air bubbles are broken after reaching the water surface and escape into the air through the air vent without adopting other pollution-preventing recovery means.

In the embodiment of the present invention, the resistance box 1, the guide rod 4, and the bubble generating plate 16 may all be made of an insulating material (such as nylon or phenolic resin), the first terminal 7, the second terminal 8, the first polar plate 2, and the second polar plate 3 are all made of a conductive metal material (such as brass), the resistance liquid is a conductive liquid (such as sodium bicarbonate), and the buoyancy ring 13 may be made of an expandable rubber material.

The application process of the water resistor with the adjustable resistance value is briefly described below.

In application, water resistors can be connected into a circuit needing to work according to design requirements through the wiring terminals of the two polar plates. The solenoid valve is placed in the off position and an external air source (e.g., an air compressor) is then connected to the valve air supply port of the solenoid valve on the tank cap via an air hose.

Then, in use, for the first example structure: if the resistance value of the water resistor needs to be increased, the electromagnetic valve is operated to the inflation position, at the moment, the external air source is communicated with the buoyancy ring 13, the buoyancy ring 13 starts to inflate and expand, the buoyancy force is increased, the guide assembly 5 is driven to move upwards along the guide rod 4, the second polar plate 3 starts to be far away from the first polar plate 2, and the resistance value is increased. When the resistance value reaches the required index, the electromagnetic valve is operated to the stop position, the buoyancy ring 13 and the external air channel are closed, the volume of the buoyancy ring is not changed any more, the guide assembly 5 is stabilized at the current depth, the distance between the first polar plate and the second polar plate is not changed any more, the resistance value is fixed, when the resistance value needs to be reduced, the electromagnetic valve is operated to the exhaust position, the air channel between the buoyancy ring 13 and the exhaust port Q2 is communicated, the air in the ring begins to exhaust to the outside (directly exhausts to the air) due to the pressure, the buoyancy ring 13 begins to reduce the volume while exhausting, the buoyancy begins to be reduced, the guide assembly 5 moves downwards along the guide rod 4, the second polar plate 3 begins to approach the first polar plate 2, and the resistance value is increased. For the second example structure: when no operation is performed, the guide assembly 5 floats on the water surface, and the distance between the first and second plates is the maximum, and the maximum resistance value state is realized. When the resistance value needs to be reduced, the electromagnetic valve is operated to connect an external air source (such as an air compressor) with the bubble generation disc 16, so that pressure air reaches the bubble generation disc 16 from the air source, and then is discharged into the resistance liquid through small holes in the surface of the bubble generation disc 16 to form a large number of small bubbles. The presence of the bubbles causes a local decrease in density of the resistive fluid (density is determined by the weight per volume, for example, 1 kg for 1 liter of water, and when 20% of air bubbles are uniformly contained in the water, the same 1 liter of water contains 0.8 liters by 1 (water density) +0.2 liters by 0.0013 (air density) — 0.8013 kg for 1 liter of water, and the overall density decreases to 0.8013), the guide member 5 begins to sink, the distance between the first and second plates decreases, and the resistance value decreases accordingly. The adjustment of the content of the bubbles in the resistance liquid can be realized by controlling the pressure and the flow of an external air source, so that the distance between the first and second polar plates is controlled, and the aim of controlling the change of the resistance value is fulfilled.

Compared with the existing water resistance which adopts a mechanical transmission type method to control the distance between two polar plates, the invention has the following advantages: on the first hand, the invention has simple structure and convenient use; in the second aspect, the distance between the polar plates is controlled by buoyancy change, electromagnetic interference of a main motor to the electric control type polar plate movement mechanism can be effectively avoided, and compared with a hydraulic control type polar plate movement mechanism, a pump station is not needed, and maintenance cost and labor are reduced.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A water resistor of adjustable resistance, comprising: resistance box (1), first polar plate (2), second polar plate (3) and buoyancy control mechanism, buoyancy control mechanism includes two guide bars (4), direction subassembly (5), buoyancy subassembly (6) and air supply, two guide bars (4) respectively with direction subassembly (5) slidable connection, resistance box (1) including the box and with box complex case lid, hold resistance liquid (1a) in resistance box (1), first polar plate (2), second polar plate (3), direction subassembly (5) and buoyancy subassembly (6) all are located resistance box (1), first polar plate (2) are fixed in the bottom of box, be equipped with first terminal (7) on the case lid, the bottom of box with the case lid is relative, first polar plate (2) with first terminal (7) electricity is connected, the second polar plate (3) is suspended over the first polar plate (2), a second binding post (8) is further arranged on the box cover, the second polar plate (3) is electrically connected with the second binding post (8), the second polar plate (3) is installed on the guide assembly (5), the guide assembly (5) comprises a support column (9), an installation arm (10) and two guide arms (11), the guide arms (11) are U-shaped, the support column (9) is parallel to the two guide rods (4) respectively, the first ends of the installation arm (10) and the first ends of the two guide arms (11) are fixed on two sides of the support column (9) respectively, the second polar plate (3) is installed at the second end of the installation arm (10), guide rings (12) are arranged at the open ends of the two guide arms (11) respectively, and the two guide arms (11) are sleeved on the two guide rods (4) respectively through the guide rings (12), the first end of guide arm (11) with the open end of guide arm (11) is relative, the first end of two guide bar (4) is fixed in the bottom of box, buoyancy module (6) be used for to direction subassembly (5) provide buoyancy, the air supply be used for doing buoyancy module (6) provide the air feed, buoyancy module (6) are including buoyancy circle (13), buoyancy circle (13) cover is located support column (9), installation arm (10) with two guide arm (11) all are located the case lid with between buoyancy circle (13).

2. Resistance-adjustable water resistor according to claim 1, characterized in that a first solenoid valve (15) is mounted on the cover, and the air supply is connected to the air tap (14) of the buoyancy ring through the first solenoid valve (15).

3. The resistance-adjustable water resistor according to claim 1, wherein the buoyancy assembly (6) further comprises a bubble generation disc (16), the bubble generation disc (16) is of a cavity structure, a plurality of small holes are distributed on the surface, facing the tank cover, of the bubble generation disc (16), and the bubble generation disc (16) is communicated with the air source.

4. Resistance-adjustable water resistor according to claim 3, characterised in that a second solenoid valve (18) is mounted on the cover, the air supply being in communication with the air tap (17) of the bubble generating disc through the second solenoid valve (18).

5. A resistance-adjustable water resistor according to claim 1, wherein a fixing clip (19) is mounted at the second end of the mounting arm (10), and the second pole plate (3) is clamped to the fixing clip (19).

6. The resistance-adjustable water resistor according to claim 5, wherein the fixing clip (19) comprises a first clip arm (20) and a second clip arm (21), the middle part of the first clip arm (20) is hinged to the middle part of the second clip arm (21) through a shaft (25), the first clip arm (20) and the second clip arm (21) are in an X shape, one end of the first clip arm (20) and one end of the second clip arm (21) which are located on the same side are provided with pre-tightening springs (22), and one end of the shaft (25) is in threaded connection with the second end of the mounting arm (10).

7. Water resistor of adjustable resistance according to any of claims 1-6, characterised in that said first plate (2) is electrically connected to said first terminal (7) by means of a first cable (23), said second plate (3) is electrically connected to said second terminal (8) by means of a second cable (24), said first cable (23) being a flat cable and said second cable (24) being a helical cable.

8. An adjustable resistance water resistor as claimed in any one of claims 1 to 6 wherein said air supply is an air supply.