DE102022004368A1 - Drive comprising an electric motor with a stator winding and a junction box - Google Patents

Abstract

Drive, having an electric motor with a stator winding and a connection box, with the winding wire ends of the stator winding being routed into the connection box, with electrical lines having at least connecting lines, in particular supply lines, and other lines being routed into the connection box, with a circuit board for signal electronics in the electric motor is arranged, which has at least one sensor for detecting a physical variable of the electric motor, the signal electronics being supplied from electrical connection elements which are arranged in the connection box and are connected to two or more of the electrical lines.

Description

The invention relates to a drive having an electric motor with a stator winding and a connection box.

It is generally known that signal electronics can be supplied from a voltage source.

From the DE 29 08 936 A1 an electric drive device is known as the closest prior art.

From the EP 2 587 642 B1 serial wiring of electric motors with integrated electronic circuit boards is known.

From the DE 10 2007 034 913 B4 a fan hood for a converter motor is known.

From the DE 36 42 724 A1 an electric motor with a frequency converter for controlling the motor operating parameters is known.

From the DE 10 2006 004 032 B4 an electric motor is known.

The invention is therefore based on the object of further developing a drive, in which case the drive should be as simple as possible to produce.

According to the invention, the object is achieved with the drive according to the features specified in claim 1.

Important features of the invention in the drive, having an electric motor with a stator winding and a connection box, are that the winding wire ends of the stator winding are routed into the connection box,
wherein electrical lines, having at least connection lines, in particular supply lines, and other lines are routed into the connection box,
a printed circuit board of signal electronics is arranged in the electric motor, which circuit board has at least one sensor for detecting a physical variable of the electric motor,
wherein the signal electronics are supplied from electrical connection elements, which are arranged in the connection box and are connected to two or more of the electrical lines.

The advantage here is that the drive is as simple as possible to produce. Because the signal electronics can be supplied from the electrical voltages that are already present in the junction box. A sensor can thus be supplied with signal electronics without a separate additional supply line being necessary.

In an advantageous embodiment, the connection box has a lower part and a cover part that is placed on the lower part. The advantage here is that the junction box accommodates the signal electronics and can be closed in a simple manner.

In an advantageous embodiment, the electrical lines are routed into the terminal box through a cable bushing accommodated in a continuous recess in the terminal box. The advantage here is that simple production is made possible.

In an alternative advantageous embodiment, the electrical lines are routed into the junction box via a plug connection, having a connector part and a mating connector part.
In particular, the mating connector part being accommodated in a continuous recess of the connection box, in particular the wall of the connection box. The advantage here is that a simple electrical connection is made possible.

In an advantageous embodiment, the circuit board is attached to a part of the electric motor,
in particular on the lower part of the connection box, on the cover part of the connection box or on a cover part forming the housing, which is connected to a stator housing part or bearing flange of the electric motor. The advantage here is that improved coupling to the connection box and thus also to the electric motor can be achieved. In particular, the structure-borne noise can be easily transmitted from a bearing of the electric motor to the connection box, which is made of metal. It is thus possible to monitor the signal that can be detected by the sensor with a good signal-to-noise ratio.

In an advantageous embodiment, the printed circuit board has recesses through which the electrical connection elements, in particular metal bolts, protrude.
wherein the connection elements are accommodated in an insulating part,
in particular wherein the insulating part is made of an insulation-proof material and/or the insulating part is made of an electrically insulating material, in particular bakelite or a ceramic-containing material or another hard insulation-proof material. The advantage here is that a particularly high signal-to-noise ratio can be achieved.

In an advantageous embodiment, the electrical connection elements, in particular metal bolts, a threaded area onto which nuts are screwed, so that the printed circuit board is touched and/or limited by one of the nuts on both sides,
in particular wherein at least one washer is interposed between the circuit board and one of the nuts or a respective one of the nuts. The advantage here is that the clamping of the printed circuit board between nuts screwed to the bolts with or without an interposed washer results in an acoustically efficient connection, in particular with the lowest possible damping. The structure-borne noise of a bearing can thus be monitored for exceeding a threshold value with a good signal-to-noise ratio.

In an advantageous embodiment, at least one washer is interposed between the printed circuit board and one of the nuts or a respective one of the nuts,
wherein the respective washer has a hexagonal recess, in particular a recess formed in the washer in the axial direction, in which the respective nut designed as a hexagon nut is received and positively connected to the washer in the circumferential direction,
in particular wherein the axial direction is aligned perpendicularly to the plane receiving the washer or parallel to the ring axis of the washer designed as a ring part,
in particular, the circumferential direction being oriented perpendicularly to the axial direction and/or perpendicularly to the direction of the ring axis. The advantage here is that the washer is designed as a ring part and the recess is introduced into the washer in the direction of the ring axis. A radially directed displacement of the washer relative to the nut is thus reliably prevented. In this way, the printed conductors can be implemented with less security, i.e. in particular with smaller distances to the washer, since the washer cannot slip and thus remains in a well-defined position. In addition, when the nut is pressed and screwed together, the frictional force between the washer and the circuit board is more relevant than the frictional force between the nut and the washer. Overall, the electrical connection is thus improved and can be reliably guaranteed, in particular against interference from the environment and/or thermal changes. This increased safety also reduces the susceptibility of sensor operation to failure, since fewer disruptions, in particular such as contact resistance changes, are generated by the now improved electrical contact and the well-defined contact surface between the washers and the printed circuit board conductor.

The nut is accommodated in the hexagonal recess or, so to speak, inserted in the axial direction during screw connection and thus secured in a form-fitting manner at least in the circumferential direction and in the radial direction.

In an advantageous embodiment, cable lugs are attached and/or threaded onto the electrical connection elements, which are connected to the winding wire ends or to the connecting lines. The advantage here is that an inexpensive, simple connection technique can be used.

In an advantageous embodiment, the recesses in the printed circuit board are designed as vias,
wherein the electrical connection elements are electrically connected to at least one of the conductor tracks of the printed circuit board. The advantage here is that the connection means are electrically connected directly.

In an advantageous embodiment, the insulating part is connected to the lower part or a housing part of the electric motor, in particular by means of screws whose screw heads press the insulating part towards the lower part or towards the housing part, in particular the screws being screwed into respective threaded bores in the lower part or the housing part. The advantage here is that an acoustically efficient connection is brought about, in particular with the lowest possible damping. The structure-borne noise of a bearing can thus be monitored for exceeding a threshold value with a good signal-to-noise ratio.

In an advantageous embodiment, the sensor is a structure-borne noise sensor, which is fitted on the printed circuit board. The advantage here is that inexpensive, simple production is made possible and a bearing of the electric motor can nevertheless be monitored with a good signal-to-noise ratio.

• - dessen wechselspannungsseitiger Anschluss direkt oder über Widerstände mit den Anschlusselementen, insbesondere eine vom Umrichter bereit gestellte Drehspannung führenden Anschlusselementen, verbunden sind und
• - dessen gleichspannungsseitiger Anschluss ein Mittel zur Spannungsbegrenzung oder Spannungsregelung speist, wobei eine Ausgangsspannung des Mittels als Versorgungsspannung der Signalelektronik, insbesondere aufweisend den Sensor, fungiert.

In an advantageous embodiment, the signal electronics have a rectifier

• - Whose AC voltage-side connection is connected directly or via resistors to the connection elements, in particular a three-phase voltage carrying connection elements provided by the converter, and
• - Whose DC-side connection feeds a means for voltage limitation or voltage regulation, with an output voltage of the means acting as a supply voltage for the electronic signaling system, in particular having the sensor.

The advantage here is that a simple, cost-effective supply is made possible.

• - dessen wechselspannungsseitiger Anschluss direkt oder über Widerstände mit den Anschlusselementen, insbesondere eine insbesondere einphasige Netzspannung führenden Anschlusselementen, verbunden sind und

dessen gleichspannungsseitiger Anschluss, insbesondere über eine galvanische Trennung, einen DC/DC-Wandler und/oder Schaltregler speist, dessen Ausgangsspannung als Versorgungsspannung der Signalelektronik, insbesondere aufweisend den Sensor, fungiert. Von Vorteil ist dabei, dass eine einfache kostengünstige Versorgung ermöglicht ist.In an advantageous embodiment, the signal electronics have a rectifier

• - Whose AC voltage-side connection is connected directly or via resistors to the connection elements, in particular connection elements carrying a single-phase mains voltage, and

whose DC voltage-side connection feeds a DC/DC converter and/or switching regulator, in particular via a galvanic isolation, whose output voltage acts as a supply voltage for the signal electronics, in particular having the sensor. The advantage here is that a simple, cost-effective supply is made possible.

• - dessen eingangsspannungsseitiger Anschluss direkt oder über Widerstände mit den Anschlusselementen verbunden sind und

dessen ausgangsspannungsseitiger Anschluss als Versorgungsspannung der Signalelektronik, insbesondere aufweisend den Sensor, fungiert. Von Vorteil ist dabei, dass eine einfache kostengünstige Versorgung ermöglicht ist.In an advantageous embodiment, the signal electronics have a DC/DC converter and/or switching regulator,

• - Its input voltage-side connection is connected directly or via resistors to the connection elements and

whose connection on the output voltage side acts as a supply voltage for the signal electronics, in particular having the sensor. The advantage here is that a simple, cost-effective supply is made possible.

In an advantageous embodiment, the electronic signaling system has an energy store for buffering the supply voltage of the electronic signaling system. The advantage here is that the signal electronics can continue to be operated even in operating states without a supply of energy. For example, if the converter supplies the motor with no AC voltage or at least not enough and/or not sufficiently steep switching edges, further operation is possible at least for a period of time determined by the storage capacity of the memory.

Further advantages result from the dependent claims. The invention is not limited to the combination of features of the claims. For the person skilled in the art, there are further meaningful combinations of claims and/or individual claim features and/or features of the description and/or the figures, in particular from the task and/or the task arising from comparison with the prior art.

• In der 1 ist ein erster erfindungsgemäßer Antrieb, aufweisend einen von einem Umrichter 100 gespeisten Elektromotor 101, schematisch skizziert.
• In der 2 ist ein zweiter erfindungsgemäßer Antrieb schematisch skizziert.
• In der 3 ist ein dritter erfindungsgemäßer Antrieb schematisch skizziert.
• In der 4 ist ein vierter erfindungsgemäßer Antrieb schematisch skizziert.
• In der 5 sind drei unterschiedliche Methoden zum Energie-Harvesting dargestellt.

The invention will now be explained in more detail using schematic illustrations:

• In the 1 a first drive according to the invention, having an electric motor 101 fed by a converter 100, is schematically outlined.
• In the 2 a second drive according to the invention is sketched schematically.
• In the 3 a third drive according to the invention is sketched schematically.
• In the 4 a fourth drive according to the invention is sketched schematically.
• In the 5 three different methods of energy harvesting are shown.

As in 1 shown, a converter 100 is used for feeding and speed control or torque control for supplying an electric motor 101 .

In this case, the electric motor 101 has a housing on which a connection box is provided.

The winding wire ends of the stator winding of the electric motor are guided inside the electric motor 101 to the connection box and connected to cable lugs 118 there.

Bolts 107 are connected to an insulating part 106 . One of the cable lugs 118 is pushed onto the respective bolt 107, with the respective cable lug 118 having a recess through which the respective bolt 118 protrudes.

A washer 108 is also pushed onto the bolt on both sides of the cable lug 118 , with each of the two washers 108 touching the cable lug 118 .

In addition, a circuit board 110 has recesses through which the bolts 107 protrude. These recesses are preferably embodied as plated-through holes on circuit board 110, so that the metal bolts are electrically connected to the plated-through holes and thus also to the conductor tracks connected to the plated-through holes.

In addition, nuts 109 are preferably screwed onto a respective threaded area of the bolts 107 and thus limit the printed circuit board axially on both sides in the direction of the bolts.

The printed circuit board is equipped with electronic components and thus provides signal electronics.

The converter 100 supplying the electric motor 101 has an inverter, which has a parallel connection of series connections has, wherein the parallel circuit is supplied from a DC voltage. Each of the series circuits has two controllable semiconductor switches, in particular IGBT or MOSFET. From the respective center tap of the respective series connection, a respective electrical line is routed as a connection line 103 through a cable bushing 105 accommodated in a recess in the connection box to cable lugs 118 which are also attached to the bolts 107 .

Due to the pulse width modulated control of the semiconductor switches, the individual phase voltages of the three-phase voltage made available to the motor by the converter have high values of the first time derivative of the voltage, in particular high values of dU/dt in terms of absolute value.

Instead of the cable lugs 118, other electrical connection elements can also be used.

The signal electronics have a rectifier for rectifying at least one of the phase voltages, with a voltage converter, in particular a DC/DC converter, being connected to the DC voltage-side connection of the rectifier, the output of which provides a supply voltage for at least one sensor. The sensor can be used to record the value of a physical variable over time, in particular torque, temperature, force, angular position or the like, and to monitor it for exceeding a threshold value or for an impermissibly large deviation from a threshold value, and depending on the result of the monitoring, the motor can be switched off or switched off reduced speed or with reduced torque operable.

The main function of the bolts 107 is the electrical connection between the stator winding wire end areas and the connection lines 103, in particular for the electrical supply of the electric motor. In addition, the bolts 107 together with the nuts 109 together with the washers 108 function as holding means for the printed circuit board 111.

To improve the electrical connection, a respective nut 109 is preferably accommodated in the hexagonal depression of the washer 108, so that the respective washer 108 is prevented from slipping in the radial direction or circumferential direction.

The printed circuit board 111 is preferably pressed by a nut 109 toward the insulating part 106, in which the bolts 107 are accommodated and preferably fastened with a material bond.

In particular, a structure-borne noise sensor is fitted on the printed circuit board 111, which is used to monitor bearing damage to the bearings of the electric motor or other impermissibly large deviations from the respectively provided operating state.

Due to the assembly on the printed circuit board 111, the structure-borne noise sensor is mechanically rigidly connected to the printed circuit board, which in turn is clamped by means of the nuts 109 resting on the printed circuit board 111 on both sides of the printed circuit board and is mechanically rigidly connected in this way to the respective bolt 107. Because the nuts 109 are screwed onto the threaded area of the bolt 107 . Since the bolt is firmly, in particular materially, connected to the insulating part 106, which is screwed to the terminal box by means of screws, the structure-borne noise from the bearing reaches the terminal box via a housing part of the electric motor that accommodates the bearing and from there via the terminal box on the inside of the terminal box Screws pressed insulating part 106, the bolt 107, the nuts 109 and the circuit board 111 to the structure-borne noise sensor.

The bearing is preferably accommodated in a housing part designed as a bearing flange, which is connected to a stator housing of the electric motor, which acts as a further piece of the housing part and is connected to the connection box, in particular is connected to a lower part of the connection box, or is designed in one piece, in particular in one piece is.

In the 2 is the printed circuit board 111 in contrast to the embodiment shown in FIG 1 deducted so spaced from the bolt 107, arranged in the junction box. In this case, the printed circuit board 111 is preferably fastened to an inner wall of the connection box. A structure-borne noise sensor fitted on the printed circuit board 111 is therefore in comparison to the embodiment according to FIG 1 connected to the bearing with fewer transitions required for structure-borne noise, so that an improved signal-to-noise ratio can be achieved.

In the 3 is arranged as a further embodiment, the circuit board 112 in a separate housing part 113 which is attached to the junction box and protrudes towards the environment. The housing part 113 is preferably accommodated in a recess which extends through the wall of the connection box. Connecting lines are routed from the printed circuit board 112 in the interior of the terminal box to the bolt 107. Energy harvesting is therefore still available, which supplies the signal electronics, in particular the structure-borne noise sensor.

In the 4 the circuit board 111 is arranged on the inside of a cover part 117, which is connected to the housing part of the electric motor. The signal electronics can be supplied by means of connection lines 114, which are electrically connected to the printed circuit board 111 on the one hand and to the bolts 107 on the other hand.

In addition, a connector comprising a connector part and a mating connector part is arranged on the connection box so that the connection lines 103 of the converter are connected to the connector part and the ends of the stator winding wires 104 are connected to the mating connector part corresponding thereto. The mating connector part is preferably arranged in a continuous recess in the connection box, in particular in the wall of the connection box. A simple, rapid connection is thus made possible, in that the connector part can be plugged into the mating connector part coming from the outside environment.

In the remarks after one of the 1 until 4 further bolts can be arranged in the insulating part of the connection box, which are provided for the transmission of further voltages. In particular, an electromagnetically actuable brake that is integrated in the motor can be supplied with a single-phase mains voltage, the further bolts serving as its connections. Coming from the outside environment, the lines for supplying the single-phase mains voltage are routed into the terminal box to the other bolts.

In the 5 three different versions of the signal electronics for carrying out the energy harvesting are shown in more detail.

In any case, the voltage present at the motor terminals, ie at the bolts 107, is tapped off 50. This enables energy harvesting by means of the signal electronics in order to detect and monitor values of physical variables by means of sensors.

In 5 the energy extraction 51 at the output voltage of the converter is symbolized schematically in the upper embodiment. This is because this output voltage is tapped off at the bolts, on the one hand for drawing energy for the signal electronics and on the other hand for the stator winding of the electric motor. The energy drawn is fed to a rectifier 54, which in turn feeds a means for voltage limitation 55, the output of which is then available as a voltage source for the electronic signaling system, which supplies the sensors and evaluates their sensor signals.

In particular, the output voltage has large values in terms of absolute value in the time derivative of the voltage signal as a result of the pulse-width modulated activation of the semiconductor switches of the inverter of the converter, so that the semiconductor components, in particular diodes, of the rectifier 54 are designed accordingly

In 5 In the middle embodiment, the energy is drawn 52 from the single-phase mains voltage, ie in particular from the supply voltage of the electromagnetically actuable brake arranged in the electric motor. The energy drawn is supplied to a switching regulator, which is designed in particular with galvanic isolation. The switching controller 56 is thus available as a voltage source for the signal electronics, which supplies the sensors and evaluates their sensor signals.

In the 5 in the lower embodiment, the energy extraction 53 is carried out using a DC voltage which is additionally introduced into the interior of the connection box 102 . For example, this is an industry standard 24 volt voltage. The energy drawn is supplied to a switching controller, in particular a DC/DC converter, which is thus available as a voltage source for the electronic signaling system, which supplies the sensors and evaluates their sensor signals.

In further exemplary embodiments according to the invention, the structure-borne noise sensor is not arranged on the printed circuit board, but is attached to the connection box or to a housing part, in particular the stator housing or bearing flange, of the electric motor and connected to the printed circuit board 112 by means of electrical lines.

Reference List

40

rotor

50

Pickup at motor terminals

51

Energy extraction converter

52

energy extraction grid

53

Energy extraction DC

54

rectifier

55

Voltage limiter or voltage regulator

56

Switching regulators with or without galvanic isolation

57

DC/DC_Converter

58

Voltage source 100 converters

101

electric motor

102

junction box

103

Inverter connection cables

104

Connecting cables insulating part

105

grommet

106

insulating part

107

bolt

108

washer

109

Mother

110

circuit board

111

circuit board, deposed

112

Circuit board, external

113

Housing

114

voltage tap

115

connector part

116

motor terminal block

117

cover part

118

cable lug

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 2908936 A1 [0003]
• EP 2587642 B1 [0004]
• DE 102007034913 B4 [0005]
• DE 3642724 A1 [0006]
• DE 102006004032 B4 [0007]

Claims (15)

Drive, having an electric motor with a stator winding and a connection box, the winding wire ends of the stator winding being routed into the connection box, electrical lines having at least connecting lines, in particular supply lines, and other lines being routed into the connection box, characterized in that in the electric motor a Printed circuit board signaling electronics is arranged, which has at least one sensor for detecting a physical variable of the electric motor, wherein the signaling electronics is supplied from electrical connection elements, which are arranged in the connection box and are connected to two or more of the electrical lines. drive after claim 1 , characterized in that the junction box has a base and a cover part which is placed on the base. Drive according to one of the preceding claims, characterized in that the electrical lines are routed into the terminal box through a cable bushing accommodated in a continuous recess in the terminal box, or that the electrical lines are routed into the terminal box via a plug connection having a connector part and a mating connector part , In particular wherein the mating connector part is accommodated in a continuous recess of the connection box, in particular the wall of the connection box. Drive according to one of the preceding claims, characterized in that the printed circuit board is attached to a part of the electric motor, in particular to the lower part of the connection box, to the cover part of the connection box or to a cover part which forms the housing and which is connected to a stator housing part or bearing flange of the electric motor. Drive according to one of the preceding claims, characterized in that the printed circuit board has recesses through which the electrical connection elements, in particular metal bolts, protrude, the connection elements being accommodated in an insulating part, in particular the insulating part being made of an insulation-resistant material and/or the insulating part is made of an electrically insulating material, in particular bakelite or a material containing ceramics. Drive according to one of the preceding claims, characterized in that the electrical connection elements, in particular metal bolts, have a threaded area onto which nuts are screwed, so that the printed circuit board is touched and/or bounded on both sides by one of the nuts. Drive according to one of the preceding claims, characterized in that at least one washer is arranged between the circuit board and one of the nuts or a respective one of the nuts, the respective washer having a hexagonal depression, in particular a depression formed in the washer in the axial direction, in which the respective nut designed as a hexagon nut is received and positively connected to the washer in the circumferential direction, in particular with the axial direction being oriented perpendicular to the plane receiving the washer or parallel to the ring axis of the washer designed as a ring part, in particular with the circumferential direction being perpendicular to the axial direction and / or is aligned perpendicular to the direction of the ring axis. Drive according to one of the preceding claims, characterized in that cable lugs are plugged and/or threaded onto the electrical connection elements and are connected to the winding wire ends or to the connecting lines. Drive according to one of the preceding claims, characterized in that the recesses in the printed circuit board are in the form of plated-through holes, the electrical connection elements being electrically connected to at least one of the conductor tracks on the printed circuit board. Drive according to one of the preceding claims, characterized in that the insulating part is connected to the lower part or a housing part of the electric motor, in particular by means of screws whose screw heads press the insulating part towards the lower part or towards the housing part, in particular, the screws being screwed into respective threaded bores in the lower part or the housing part. Drive according to one of the preceding claims, characterized in that the sensor is a structure-borne noise sensor which is fitted on the printed circuit board. Drive according to one of the preceding claims, characterized in that the signal electronics have a rectifier, - the AC voltage-side connection of which is connected directly or via resistors to the connection elements, in particular a three-phase voltage-carrying connection element provided by the converter, and - the DC voltage-side connection of which has a means for limiting the voltage or voltage regulation, with an output voltage of the means acting as a supply voltage for the signal electronics, in particular having the sensor. Drive according to one of the preceding claims, characterized in that the signal electronics have a rectifier, - whose AC voltage-side connection is connected directly or via resistors to the connection elements, in particular a connection element carrying a single-phase mains voltage, and - whose DC voltage-side connection, in particular via a galvanic isolation , a DC/DC converter and/or switching regulator, the output voltage of which acts as a supply voltage for the signal electronics, in particular comprising the sensor. Drive according to one of the preceding claims, characterized in that the signal electronics have a DC/DC converter and/or switching regulator, - whose input voltage-side connection is connected directly or via resistors to the connection elements and - whose output voltage-side connection as supply voltage for the signal electronics, in particular having the sensor. Drive according to one of the preceding claims, characterized in that the electronic signaling system has an energy store for buffering the supply voltage of the electronic signaling system.

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