阅读说明：本技术 用于废水应用和/或供水的泵 (Pump for waste water applications and/or water supply ) 是由 C·埃尔威恩 于 2019-08-05 设计创作，主要内容包括：本发明涉及用于废水应用和/或供水的泵。根据本发明的泵具有泵壳和电动机、以及与该泵相连接的电动机保护装置,其中该电动机保护装置设有电导率传感器并且该电导率传感器的第一触点与泵壳电连接。此外,该电动机保护装置具有带有微处理器的保护继电器,该微处理器与电导率传感器相连接以用于分析该电导率传感器的输出信号,其中该微处理器与泵壳的接地电位电连接并且至少另一传感器连接到该微处理器。(The present invention relates to pumps for waste water applications and/or water supply. The pump according to the invention has a pump housing and an electric motor, and a motor protection device connected to the pump, wherein the motor protection device is provided with a conductivity sensor and a first contact of the conductivity sensor is electrically connected to the pump housing. The motor protection device furthermore has a protective relay with a microprocessor which is connected to the conductivity sensor for evaluation of the output signal of the conductivity sensor, wherein the microprocessor is electrically connected to the ground potential of the pump housing and at least one further sensor is connected to the microprocessor.)

1. A pump (1) for waste water applications and/or water supply, the pump (1) having a pump housing (2) and an electric motor (3), and a motor protection device (4) connected to the pump, wherein the motor protection device (4) has a conductivity sensor (7) and a first contact of the conductivity sensor (7) is electrically connected to the pump housing (2), and the motor protection device (4) is provided with a protection relay (5) with a microprocessor (6), the microprocessor (6) is connected to the conductivity sensor (7) for analyzing an output signal of the conductivity sensor (7), wherein the microprocessor (6) is electrically connected to a ground potential (20) of the pump housing (2) and at least one further sensor (8-11) is connected to the microprocessor (6).

2. Pump (1) according to claim 1, characterized in that the conductivity sensor (7) is based on ohmic resistance measurements.

3. Pump (1) according to claim 1, characterized in that the conductivity sensor (7) has a second contact which is electrically isolated with respect to the pump housing (2) and which is connected to the microprocessor (6).

4. Pump (1) according to claim 1, characterized in that said further sensor is constituted by an acceleration sensor (8) for measuring the vibrations of a bearing (24) of the pump (2).

5. Pump (1) according to claim 4, characterized in that the acceleration sensor (8) has a housing which is electrically connected with the first contact of the conductivity sensor (7).

6. Pump (1) according to claim 5, characterized in that the acceleration sensor (8) has a measuring lead (15a) which is electrically isolated with respect to the pump housing (2) and which is connected to the microprocessor (6).

7. Pump (1) according to claim 1, characterized in that the further sensor is constituted by a bearing temperature sensor (9) for measuring the temperature of at least one bearing of the pump (1).

8. Pump (1) according to claim 7, characterized in that the housing of the bearing temperature sensor (9) is electrically connected with the first contact of the conductivity sensor (7).

9. Pump (1) according to claim 1, characterized in that said further sensor is constituted by a winding temperature sensor (10) for measuring the temperature of the windings of the electric motor (3).

10. Pump (1) according to claim 9, characterized in that the winding of the electric motor (3) is configured as a toothed coil winding with a plurality of grooves and the winding temperature sensor has two connecting strands arranged in the same groove.

11. Pump (1) according to claim 1, characterized in that said further sensor is constituted by a phase monitoring sensor (11) for measuring the phase of a supply voltage (12) for the electric motor.

12. Pump (1) according to claim 10, characterized in that the phase monitoring sensor (11) is electrically and/or inductively connected with the first contact of the conductivity sensor (7) by a feed network.

13. Pump (1) according to claim 1, characterized in that said motor protection means (4) have a power supply (13) connected to said microprocessor (6).

14. Pump (1) according to claim 1, characterized in that the pump (1) is a centrifugal pump or an eccentric pump.

Technical Field

The present invention relates to pumps for water supply or waste water applications.

Background

Such pumps are valuable investment items with high procurement costs and long replacement times. Accordingly, it is desirable to protect these work machines from damage caused by critical operating conditions, faulty operation, or overload. According to the prior art, protective relays from manufacturing automation are generally used. These relays monitor, for example, the winding temperature of the motor, the temperature of the bearings, or the leakage of the pump. Here, a separate protective relay is used for each measured value.

In practice, in the protection of pumps, false alarms due to EMV disturbances always occur, which cause the pumps to shut down without real failure, thus disturbing the infrastructure in the supply and waste water treatment. Furthermore, unnecessary costs are incurred for the water supply operator because the service technician must investigate the fault report.

Disclosure of Invention

The object of the invention is therefore to increase the reliability of the pump protection and at the same time to allow a complete monitoring of the various parameters of the pump.

According to the invention, this object is achieved by the features of claim 1.

The pump according to the invention has a pump housing and an electric motor, and a motor protection device connected to the pump, wherein the motor protection device is provided with a conductivity sensor and a first contact of the conductivity sensor is electrically connected to the pump housing. The motor protection device furthermore has a protective relay with a microprocessor which is connected to the conductivity sensor for evaluation of the output signal of the conductivity sensor, wherein the microprocessor is electrically connected to the ground potential of the pump housing and at least one further sensor is connected to the microprocessor.

As opposed to using separate microprocessors for each sensor, it is proposed according to the invention that at least the conductivity sensor and at least one further sensor, preferably all sensors, are connected to a common microprocessor. Although it is known from practice that the protective relay has inputs for a plurality of sensors, this is a temperature sensor which is not electrically coupled to the pump housing. However, according to the invention, a conductivity sensor should be used, which is used, for example, for level or leakage measurements, the first contact of which is electrically connected to the pump housing.

In the prior art, each sensor is connected to its own protective relay, each in turn having its own microprocessor and its own power supply. This can result in an electrical coupling of the measuring circuits which are virtually separated from one another. Furthermore, at different power sources, a potential difference may be obtained, which, due to a common potential point on the pump, may result in a balancing current between the various protective relays. These balancing currents may be part of the cause of false alarms. By using a common microprocessor for the conductivity sensor and the at least one further sensor, the problems of the resulting potential difference and the resulting disturbing balancing current can be avoided.

Other constructive designs of the present invention are the subject of the dependent claims.

The conductivity sensor may be used as a level sensor to prevent dry running of the pump. Furthermore, the conductivity sensor may also be used as a leak sensor, for example to monitor water penetration into certain areas of the pump.

According to a preferred embodiment of the invention, the conductivity sensor is based on an ohmic resistance measurement. Furthermore, the conductivity sensor may have a second contact electrically isolated from the pump housing and connected to the microprocessor. The at least one further sensor connected to the microprocessor may for example consist of an acceleration sensor for measuring the vibrations of the bearings of the pump. The acceleration sensor can have a housing which is electrically connected to the first contact of the conductivity sensor. Furthermore, the acceleration sensor can have a measurement line which is electrically isolated from the pump housing and which is connected to the microprocessor.

However, the further sensor can also be formed, for example, by a bearing temperature sensor for measuring the temperature of at least one bearing of the pump, wherein it is also conceivable here for the housing of the bearing temperature sensor to be electrically connected to the first contact of the conductivity sensor.

According to a further embodiment of the invention, the further sensor can also be formed by a winding temperature sensor for measuring the temperature of the windings of the electric motor. The winding of the electric motor can be designed as a tooth coil winding with a plurality of recesses, wherein advantageously the two connection strands of the winding temperature sensor are arranged in the same recess, since EMV coupling can occur due to potential differences if the connection strands are arranged in different recesses.

Furthermore, the possibility exists of: the further sensor is formed by a phase monitoring sensor for measuring the phase of the supply voltage used by the motor. There is also the possibility here of: the phase monitoring sensor is electrically and/or inductively connected to the first contact of the conductivity sensor via a feed network. In addition to the conductivity sensor, one or more, preferably all, of the other sensors mentioned above may be connected to the microprocessor. It is of course also conceivable that sensors which monitor other parameters and are not explicitly mentioned above are connected to this common microprocessor.

According to a further embodiment of the invention, it is provided that the motor protection device has a power supply which is connected to the microprocessor in order to provide the sensor with the required measurement voltage.

According to a preferred embodiment of the invention, the pump is a centrifugal pump or an eccentric pump.

Drawings

Other configurations and advantages of the present invention are explained in the following description of embodiments in conjunction with the accompanying drawings.

In the drawings:

fig. 1 shows a block diagram of a pump with a motor protection according to the invention, an

Fig. 2 shows a circuit diagram of the motor protection device.

Detailed Description

The pump 1 shown in fig. 1 refers to a centrifugal or eccentric pump, for example for water supply or waste water applications. It has a pump housing 2 and an electric motor 3 arranged inside the pump housing 2. The pump 1 is also connected to a motor protection device 4 having a protection relay 5 with a microprocessor 6. In addition, the motor protection device is provided with various sensors connected to the protection relay 5 or the microprocessor 6, i.e., a conductivity sensor 7, an acceleration sensor 8, a bearing temperature sensor 9, and a winding temperature sensor 10. Furthermore, a phase monitoring sensor 11, which is provided for measuring the phase of the supply voltage 12 used by the electric motor 3, may be connected, for example.

The motor protection device 4 also has a power supply 13, which is arranged in the protective relay 5 and is connected to the microprocessor 6. The various sensors 7-11 are connected to the protective relay 5 or microprocessor 6 by wires 14-18. Furthermore, reference numeral 19 also shows an operator interface which forms an interface between the motor protection 4 and an operator. On this interface, data, in particular an alarm signal of the protective relay 5, can be visualized, for example.

Fig. 2 shows a circuit diagram between the sensor and the microprocessor 6, for example, in terms of a conductivity sensor 7 and an acceleration sensor 8. The pump housing 2 is at ground potential 20, which is usually formed by ground potential. The conductivity sensor 7 has a pin 7a, which is arranged in an insulated manner with respect to the pump housing 2 and is connected to the microprocessor 6 via a line 14 a. The input circuit for the input of the microprocessor 6 is shown here, for example, by a series resistor 21 and a low-pass filter consisting of a resistor 22 and a capacitor 23. Here, the insulating pin 7a shows a second contact of the conductivity sensor 7. The other (first) contact of the conductivity sensor 7 is electrically connected to the pump housing 2 and to the microprocessor 6 via a line 14 b.

The acceleration sensor 8 is used to measure the vibration of a bearing 24 (e.g., a ball bearing) in the pump 1. An exemplary input circuit in the microprocessor 6 is constructed similarly to the conductivity sensor 7. The ground line 15b of the acceleration sensor 8 is connected to the metal casing of the acceleration sensor and is therefore also at ground potential 20. In contrast, the measuring line 15a enters the acceleration sensor 8 in an insulated manner.