Pump with float arm and hysteresis function

Abstract

The invention relates to a submersible motor pump which comprises a float (6) that interacts with a switch (14) for the automated control of the pumping operation. The switch (14) switches the pump on at an upper limit value and switches the pump off at a lower limit value. The switch (14) is connected to a motion member (13) which has an inner magnet (12), the inner magnet (12) being connected to an outer counter magnet (10) which is arranged in a pivotable magnet holder (9). The magnet holder (9) is connected to a lever arm (5) of the float (6) which is designed to be pivotable in its position depending on the surrounding liquid level. The pivoting movement of the magnet holder (9) is at least partially decoupled from the pivoting movement of the float (6).

Description

[0001] Pump with float arm and hysteresis function

[0002] The invention relates to a submersible motor pump comprising a float which interacts with a switch for the automated control of the pumping process in such a way that the switch switches the pump on at an upper limit value and switches the pump off at a lower limit value, wherein the switch is connected to a moving member which has an inner magnet, wherein the inner magnet is connected to an outer counter magnet which is arranged in a pivotable magnet holder, wherein the magnet holder is connected to a lever arm of a float which is designed to be pivotable in its position depending on the surrounding liquid level.

[0003] A sewage pump, also known as a dirty water pump, is used to pump heavily contaminated water, which often contains solid particles of various organic, inorganic, or mineral origins. Sewage pumps are typically single-stage and generally not self-priming. Instead, they are usually completely submerged in the fluid being pumped. A wet-mounted sewage pump is also called a submersible pump.

[0004] A submersible pump, also known as a submersible pump, is a special type of pump used for pumping liquids. The term "submersible pump" refers to the pump's design, in which the motor is located directly in the liquid to be pumped. The pump consists of a housing containing the motor and impeller. The motor is sealed to be watertight and is submerged directly in the liquid. The impeller is located at the bottom of the pump and is connected to the motor. When the motor is switched on, the impeller rotates, creating suction that draws in the liquid and pushes it through the pump.

[0005] Submersible pumps are commonly used in applications where water or other liquids need to be pumped from pits, wells, basements, or other low-lying areas. They are also used in industry, agriculture, and construction to drain water or assist with drainage.

[0006] For installation, the submersible pump is typically lowered into the pump sump along a guide. A bracket attached to the pump, which contains a rubber profile seal, allows the submersible pump to be connected to the permanently installed pipe in the pump sump with virtually no leakage, allowing the unit to be completely submerged. The externally wetted motor housing then transfers the motor heat to the surrounding pumped medium.

[0007] The submersible motor pump is usually single-stage and built in a block design and may not even require a suction line, as the pumped medium flows to it from all sides.

[0008] Smaller units are portable and usually equipped with a level-controlled switch for automatic on and off switching.

[0009] DE 44 34 461 A1 describes a submersible pump for heavily contaminated liquids. To facilitate the cleaning of deposits inside the pump, the submersible pump, which is equipped with a tangential discharge port and a casing chamber surrounding the motor and through which the pumped liquid flows, has a flushing connection located at the end of the casing chamber facing away from the pump and connected to an external liquid source. The level-controlled switches in submersible pumps are occasionally susceptible to malfunctions. Contaminants in the liquid can affect these switches, leading to delays or even failures in switching. Furthermore, high-frequency switching cycles can lead to a shortened service life of the pump's motor.

[0010] DE 19 745 184 A1 discloses a float switch for switching an electric motor on and off, in particular for a submersible pump unit, comprising a first magnet whose position can be changed by a float depending on the liquid level. The first magnet corresponds to a second magnet separated from it by a non-magnetic wall in such a way that the second magnet, connected to an actuating element acting on the switch of the electric motor, is moved by the approaching first magnet from a first switching position assumed in the uninfluenced state to a second switching position. In order to be able to operate an electric motor equipped with such a float switch optionally with or without a float switch, the invention provides that the two magnets repel one another.

[0011] The object of the invention is to provide a submersible pump with a float that automatically implements a pumping process depending on the liquid level. The design of the float is intended to enable automation with a reduced number of switching cycles. Furthermore, the submersible pump with the float is intended to be suitable for pumping contaminated liquids. Furthermore, the submersible pump is intended to be characterized by a compact design and to be suitable for wet installation. The design of the submersible pump is intended to facilitate the replacement of spare parts. The submersible pump is intended to be simple and cost-effective to implement.

[0012] This object is achieved according to the invention by a submersible motor pump according to the features of claim 1. Preferred variants can be found in the independent main claims, the subclaims, the description and the drawings. According to the invention, the pivoting movement of the magnet holder is

[0013] The swivel movement of the float is at least partially decoupled.

[0014] In a preferred variant of the invention, the pivoting movement of the magnet holder is decoupled from the pivoting movement of the float by more than 5°, preferably by more than 10°, in particular by more than 15°, and / or by less than 50°, preferably by less than 45°, in particular by less than 40°.

[0015] A panning motion refers to a rotational motion around a specific point or axis. A panning motion moves an object from one point one step further, rotating around a specific point or axis.

[0016] In contrast to rotation, in which an object rotates around its own axis, panning motion is movement around an external point or axis. It allows for lateral translation or panning of an object while simultaneously rotating it around the pivot point.

[0017] Advantageously, the decoupled swivel movement realizes the control of the pumping process at defined points of the filling level of the submersible motor pump.

[0018] This allows the pumping process to be started when the float is positioned slightly below the 9 o'clock position, especially at the 7 o'clock position, or when it is almost horizontal. This corresponds to a fill level at which the float mechanism is just not covered by the surrounding fluid, for example, the dirty water.

[0019] At the same time, the partial decoupling of the swivel movement leads to the pumping of the surrounding fluid down to the lowest possible liquid level at which the submersible pump can still pump. The partially decoupled swivel movement of the float from the swivel movement of the magnet holder creates a hysteresis behavior in the pumping process of the submersible pump, which is particularly advantageous with regard to the switching cycles of the pump motor and thus ideally supports the service life and durability of the motor.

[0020] A float position refers to the position of a float in a liquid container or floating device. A float is a mechanical component that can float in liquids and changes its position according to the liquid level.

[0021] The float position is often used to control the liquid level in a container. The float is usually attached to an arm, lever, or rod connected to a switching device. Depending on the liquid level, the float moves up and down, thereby changing the position of the lever or rod.

[0022] In the control application, the float position can be used to enable automatic control of the fluid level. When the fluid level reaches a certain value, the float can activate a switching device to turn on a pump to regulate the fluid level.

[0023] The lever arm is usually defined as the perpendicular distance from the axis of rotation of the lever to the line or point where the force acts.

[0024] Ideally, the lever arm is designed as an external connection between the float and the magnet holder.

[0025] For example, the lever arm has a head which comprises a guide groove and the magnet holder has at least one projection which engages in the guide groove, wherein the head has at least one segment which forms a stop for the projection to form a pair of active surfaces.

[0026] The head has a guide groove which can, for example, be divided into two parts, whereby the parts of the guide groove can be divided by two segments within the guide groove.

[0027] For example, a corresponding number of projections of the magnet holder engage in the parts of the guide groove.

[0028] Ideally, the segments each have a stop, which forms a pair of active surfaces with a projection of the magnet holder.

[0029] Advantageously, in a “low liquid level” float position, a gap is formed between the segment and the projection.

[0030] In the “low fluid level” float position, a gap is preferably formed between each segment and each projection.

[0031] As the fluid level rises, the float pivots with the lever arm until the gap is closed and the segments and projections form a pair of active surfaces. The resulting pair of active surfaces causes the magnet holder to pivot, so that as the fluid level continues to rise and the lever arm pivots, the magnet holder pivots along with it.

[0032] For example, the magnet holder can pivot up to a maximum stop on the housing, which limits the pivoting movement. The outer counter magnet can attract the inner magnet shortly before reaching the stop, thus activating the pumping process.

[0033] For example, the pair of active surfaces is designed to realize a pivoting movement of the magnet holder. A pair of active surfaces refers to two contacting or interacting surfaces in a mechanical device or machine. These surfaces are designed to fulfill a specific function or enable force transmission.

[0034] An active surface pair consists of an active surface and a reactive surface. The active surface is the one that exerts a force on the reactive surface, while the reactive surface is the one to which the force is exerted. These two surfaces are designed to interact with each other and fulfill the desired function: pivoting the magnet holder.

[0035] The switch is preferably designed as an opener.

[0036] A normally closed switch is a switch that opens a connection or circuit when actuated. Normally closed switches can be mechanical or electronic. Mechanical normally closed switches are often triggered by physical action such as pushing, tilting, or turning.

[0037] Advantageously, the switch is designed as a normally closed contact.

[0038] A "normally open" switch is an electrical switch that closes a connection or circuit when actuated. It is also called a "normally open" switch. In contrast, a "normally closed" switch opens the circuit when actuated. Normally open switches can be mechanical or electronic. The mechanical normally open switch is triggered by the tilting movement achieved by the magnetic action of the internal and external magnets.

[0039] Ideally, the inner magnet and the outer counter magnet have an attractive effect. In an alternative variant of the invention, the inner magnet and the outer counter magnet have a repulsive effect.

[0040] For example, the lever arm and / or the magnet holder and / or the housing have corresponding parts of a clip connection. This allows the head of the lever arm with the pivoting magnet holder to be clipped to a housing of the submersible pump.

[0041] A clip connection is a fastening method in which two components or parts are joined together by a snapping or locking movement. The connection is achieved by special clips or locks that are installed in one component and snap into the corresponding recesses or brackets of the other component.

[0042] For example, a housing part of a submersible motor pump has two clip bars to form a clip connection with the head of the lever arm. In this design variant, the head of the lever arm has recesses and locking lugs into which the clip bars can snap.

[0043] By using clips, the components can be joined together quickly and easily, without the need for additional tools or fasteners. A clip connection also allows for easy disassembly of the connected components without the need for special tools. This facilitates maintenance and repair. It can maintain sufficient holding force and prevents accidental loosening or displacement of the parts.

[0044] In an alternative variant of the invention, the lever arm has a force-locking connection to the magnet holder. In this embodiment, the head of the lever arm is preferably fixed to the magnet holder and / or to a housing part of the submersible pump with a screw connection. According to the invention, the method for the automated control of the pumping process of a submersible pump comprises the following steps: moving the float depending on the surrounding liquid level, moving the segment of the lever arm until the active surface pair is formed with the projection of the magnet holder in the guide groove, pivoting the magnet holder from a low to an upper position, interacting with the magnets to move the moving element, whereby the switch switches the pump on.

[0045] For example, the pump housing has a receiving pin on which the magnet holder is arranged, as well as a float body with a receiving device. The connection between the float body and the magnet holder is realized by a cover. The float holder is positioned axially to the pin but has no axial contact with the magnet holder. The magnet holder and the float holder only have contact in a rotational orientation. This contact is achieved through the interaction of the pair of active surfaces after the partial decoupling has been overcome. The resulting gap or slip allows a defined rotation without the magnet holder moving.After the gap in the guide groove has been overcome by the pivoting movement of the float to the magnet holder, the magnet holder is carried along by the float and, after a further joint movement clockwise, causes the pump to switch. This moves the magnet to the position where the inner magnet is attracted to the outer counter magnet in the magnet holder. The switch is activated by a tilting movement of the moving element, energizing the motor, and starting the pumping process of the submersible pump.

[0046] During pump operation, the fluid level decreases and the float moves counterclockwise back down. Initially, the float moves downward without the magnet due to the decoupling of the pivoting movement. After the gap described above is closed and the float has reached its "low level" fluid position, the outer magnet in the magnet holder pivots away from the inner magnet. This causes the tilting element or the moving element to move, and the switch moves to the "off" position. The motor stops, and the pumping process is deactivated.

[0047] The gap described above preferably allows for a longer pumping cycle of the submersible motor pump, as the pump is only activated when the fill level is just below the lever head and remains activated until the lowest possible fill level is reached. The resulting hysteresis of the pumping process advantageously reduces the motor's switching cycles.

[0048] Ideally, the float is externally mounted, stable, and effective. This allows the torque to be reliably transmitted through the movement of the float, enabling the submersible pump to pump out even heavily contaminated wastewater.

[0049] According to the invention, a submersible motor pump with a float is used to create a hysteresis during the pumping process.

[0050] Ideally, the design of the active surface pair reduces the switching cycles of the pump and thus ideally realizes the service life of the motor.

[0051] Further features and advantages of the invention will become apparent from the description of embodiments with reference to the drawings and from the drawings themselves.

[0052] It shows:

[0053] Fig. 1 is a sectional view of a known submersible motor pump,

[0054] Fig. 2 a simplified exploded view of the float and magnet holder,

[0055] Fig. 3 is a perspective detailed drawing of the lever arm head and the magnet holder. The known submersible motor pump shown in Fig. 1 essentially consists of a pump housing 1 and an electric motor 2 arranged therein, which drives a centrifugal pump impeller 4 via a shaft 3. On the outside of the pump housing 1, a float 6 is arranged on a lever arm 5. The lever arm 5 is fastened to a shaft 7, which is mounted in a housing 8 placed on the pump housing 1. A magnet holder 9, which accommodates an external counter magnet 10, is connected in a rotationally fixed manner to the shaft 7. The position of the float 6 relative to the magnet 10 can be changed by means of a screw 11. This enables the switching positions of the float switch to be adjusted, which depend on the liquid level.

[0056] The known design of the submersible motor pump uses an inner magnet 12 whose polarity is opposite to that of the outer counter magnet 10, so that the two magnets 10 and 12 attract each other when they approach each other. The inner magnet 12 is attached to a moving member 13 in the form of a rocker arm, which actuates a switch 14 when the outer counter magnet 10 approaches the wall of the housing 1, which is made of a non-magnetic material. The switch 14 is designed as a normally open switch and, when actuated, switches on the electric motor 2. This is the case when the float 6 is at the predetermined switch-on height, i.e. when the inner magnet 12 comes so close to the outer counter magnet 10 that the attractive force of the magnets 10 and 12 begins to take effect.

[0057] The now activated operation of the submersible pump pumps the liquid surrounding the unit, causing the liquid level to drop and the float 6 to gradually sink. This also causes the outer magnet 10 to steadily move away from the inner magnet 12. As soon as the attractive force of the two magnets 10 and 12 falls below the restoring force acting on the moving member 13, the rocker arm moves the inner magnet 12 away from the wall of the pump housing 1, the switch 14 opens, and the electric motor 2 of the submersible pump is switched off. Fig. 2 shows an exploded view of the float 6, the magnet holder 9, and the submersible pump. The float 6 is designed as an extension of the lever arm 5. The lever arm 5 originates from a head 15. The magnet holder 9 has two projections 16 that engage in the guide groove 17 (not visible in Fig. 2).

[0058] The housing 8 has two clip webs 18 for forming a clip connection with the head 15 of the lever arm 5. Furthermore, an upper stop 19 and a lower stop 20 are arranged on the housing 8 to limit the pivoting movement of the magnet holder 9. Furthermore, the housing 8 comprises a cylindrical wall 21 that supports and guides the cylindrical part 22 of the magnet holder 9.

[0059] Fig. 3 shows a perspective detailed drawing of the head 15 of the lever arm 5 and the magnet holder 9. The head 15 has a guide groove 17. In the illustrated embodiment, the guide groove 17 is divided into two parts separated by two segments 23. The two projections 16 engage in the parts of the guide groove 17, with the segments 23 each having a stop 24, which forms a pair of active surfaces with each projection 16.

[0060] The magnet holder 9 has a space 25 in which the outer counter magnet 10 is arranged.

[0061] In the "low fluid level" float position, a gap is formed between each segment 23 and each projection 16. As the fluid level rises, the float 6 pivots with the lever arm 5 until the gap is closed and the segments 23 make contact with the projections 16 at the stop 24. This creates the pair of active surfaces for pivoting the magnet holder 9, so that as the fluid level continues to rise and the lever arm 5 pivots, the magnet holder 9 pivots along with it.

[0062] The magnet holder 9, moved by the float 6, can pivot up to the maximum upper stop 19, whereby the outer counter magnet 10 attracts the inner magnet 12 and thus activates the pumping process as previously described. Due to the gap between each segment 23 and each projection 16, the pivoting movement of the magnet holder 9 is decoupled from the pivoting movement of the float 6 by 20° at low fluid levels.

[0063] Compared to conventional submersible pumps, this gap enables a longer pumping process, as the pump is only activated when the fluid level is just below the head 15 of the lever arm 5 and remains activated until the lowest possible fluid level is reached. The resulting hysteresis of the pumping process reduces the switching cycles of motor 2 and thus extends the service life of the submersible pump.

Claims

Patent claims 1. Submersible motor pump comprising a float (6) which interacts with a switch (14) for the automated control of the pumping process such that the switch (14) switches the pump on at an upper limit value and switches the pump off at a lower limit value, wherein the switch (14) is connected to a movement member (13) which has an inner magnet (12), wherein the inner magnet (12) is connected to an outer counter magnet (10) which is arranged in a pivotable magnet holder (9), wherein the magnet holder (9) is connected to a lever arm (5) of the float (6), which is designed to be pivotable in its position depending on the surrounding liquid level, characterized in that the pivoting movement of the magnet holder (9) is designed to be at least partially decoupled from the pivoting movement of the float (6).

2. Submersible motor pump according to claim 1, characterized in that the pivoting movement of the magnet holder (9) is decoupled from the pivoting movement of the float (6) by more than 5 °, preferably by more than 10 °, in particular by more than 15 °, and / or by less than 50 °, preferably by less than 45 °, in particular by less than 40 °.

3. Submersible motor pump according to claim 1 or 2, characterized in that the lever arm (5) has a head (15) which comprises a guide groove (17) and the magnet holder (9) has at least one projection (16) which is inserted into the Guide groove (17), wherein the head (15) has at least one segment (23) which forms a stop (24) for forming a pair of active surfaces for the projection (16).

4. Submersible motor pump according to claim 3, characterized in that when the float position is low, a gap is formed between the segment (23) and the projection (16).

5. Submersible motor pump according to claim 3 or 4, characterized in that the pair of active surfaces is designed for pivoting movement of the magnet holder (9).

6. Submersible motor pump according to one of claims 1 to 5, characterized in that the switch (14) is designed as an opener.

7. Submersible motor pump according to one of claims 1 to 5, characterized in that the switch (14) is designed as a normally open contact.

8. Submersible motor pump according to one of claims 1 to 7, characterized in that the inner magnet (12) and the outer counter magnet (10) have an attractive effect.

9. Submersible motor pump according to one of claims 1 to 7, characterized in that the inner magnet (12) and the outer counter magnet (10) have a repulsive effect.

10. Submersible motor pump according to one of claims 1 to 9, characterized in that the lever arm (5) and / or the magnet holder (9) and / or the housing (8) have corresponding parts of a clip connection. 11 . Submersible motor pump according to one of claims 1 to 9, characterized in that the lever arm (5) on the magnet holder (9) and / or on the housing (8) has a force-locking connection.

12. Method for the automated control of the pumping process of a submersible motor pump with the following steps: - movement of the float (6) depending on the surrounding liquid level, - Movement of the segment (23) of the lever arm (5) to form the pair of active surfaces with the projection (16) of the magnet holder (9), - Swiveling the magnet holder (9) from a low to an upper position, - Interaction of the magnets (10, 12) to move the moving member (13), whereby the switch (14) switches on the motor (2) of the pump.

13. Use of a submersible motor pump according to one of claims 1 to 11 with a float (6) for forming a hysteresis during the pumping process.

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