DE102007039704A1 - Gearbox's rate of remaining operation time and remaining rotations, alarm and/or warning determining system, has comparison unit with output side connected with outputs of evaluation unit and indication unit that indicates alarm and warning - Google Patents

Abstract

The system has a proximity sensor (4) determining an angle-related parameter such as angular speed, of a shaft of a gearbox (8), which is driven by an electric motor. An evaluation unit (1) i.e. expansion card, includes a comparison unit comparing a value stored in a memory of the evaluation unit and a value determined from sensor signals. An output side of the comparison unit is connected with outputs (3) of the unit (1) and/or an indication unit (2) of the unit (1), where the indication unit indicates a rate of remaining operation time, rate of remaining rotations, alarm and/or a warning. An independent claim is also included for a method for determining a rate of remaining operation time, a rate of remaining rotations, an alarm and/or a warning of a gearbox.

Description

The The invention relates to a system and a method.

It is known geared motors from the grid directly or via inverter to supply.

Of the The invention is therefore based on the object of safety in systems to increase.

According to the invention The object of the system according to claim 1 and in the method After the solved in claim 8 features.

Important features of the invention in the apparatus and in the method are that the system comprises at least one gear driven by an electric motor and an evaluation unit,
wherein a sensor for detecting an angle-related quantity, such as number of revolutions, angle and / or angular speed of a shaft of the transmission,
wherein the evaluation unit comprises comparison means which, on the one hand, are supplied with a value stored in a memory of the evaluation unit and, on the other hand, a value determined from the sensor signals is supplied,
wherein the comparison means are connected on the output side to at least one output of the evaluation unit and / or display means of the evaluation unit, in particular for displaying a remaining operating hours number, a residual rotation number, an alarm and / or a warning.

From The advantage here is that the safety in systems is increased, because a maintenance in time before the critical time range, in which the drive fails, executable and the appointment for this is predictable.

at According to an advantageous embodiment, the sensor is an inverter, this means for detecting motor current and / or motor voltage and means for forming model values which the evaluation unit, in particular by means of an electrical or wireless connection, supplied become. The advantage here is that no additional sensor but the any inverter available to power the electric motor anyway is.

at an advantageous embodiment, the sensor is a proximity sensor, in particular a on a housing part gearbox mounted proximity sensor. The advantage here is that a simpler cost-effective Sensor is used and thus the electronics of the evaluation very easy and inexpensive is configurable.

at In an advantageous embodiment, the evaluation unit is a plug-in card executed in particular a computer, an inverter or a field device. From The advantage here is that the housing another device that can be used in the system anyway is. Furthermore Model values of the inverter can be transferred quickly and without interference to the card.

at In an advantageous embodiment, the sensor detects teeth of a Gearing part, in particular the removal and / or the passing the teeth. The advantage here is that the rotational movement in a simple manner is detectable.

at an advantageous embodiment are means for determining the Loading condition of the transmission or geared motor connected with the evaluation unit. The advantage here is that in the determination the remaining operating time the load present in the respective time step is considered, in particular directly from the evaluation unit.

at In an advantageous embodiment, the sensor also acts as a means for determining the load condition. The advantage here is that no additional Sensor must be used. The execution is particularly simple, though the sensor is an angular velocity sensor. When the sensor is on Angle sensor is, by simply differentiating the angular velocity determinable. Thus, an angle sensor can be used advantageously. The mentioned proximity sensor works with your teeth together that it can also be used as an angle sensor, in particular with a resolution, the distance of the teeth is determined.

Important features of the method are that it is intended to determine a remaining number of hours of operation, a residual number of revolutions, an alarm and / or a warning,
wherein an angle-related quantity, such as number of revolutions, angle and / or angular velocity of a shaft or the like, is detected,
wherein a value for number of operating hours, number of revolutions is determined from the detected values of the angle-related variable, and this specific value is compared with a value stored in a memory, in particular in each time step,
whereby a warning and / or an alarm is triggered when the stored value is exceeded or undershot,
in particular, wherein from the difference of the determined value and the stored value, a value for remaining hours of operation and / or residual revolution number is determined and displayed.

The advantage here is that a residual operating time or number of revolutions is determined from a detected angle value. Thus, also a prognosis foreseeable for a maintenance date.

at an advantageous embodiment is from the detected values the angle-related quantity is a value for operating hours, The number of revolutions determined by the amount of the detected value as Function of time is integrated and / or the value of the integral the detected value is determined as a function of time, in particular from start of operation to the current time step. It is advantageous that in each time step the integral is added by adding the current one Value of the integrand in a simple manner with little computational effort is determinable.

at an advantageous embodiment is from the detected values the angle-related quantity is a value for operating hours, Rotation speed is determined, taking into account the load condition is and where for different values of the load condition different stored values be used. In particular, the collected values of the angle-related size a value for operating hours, Number of revolutions is determined by the amount of the detected value with a load state-dependent factor belonging to the respective time step is multiplied and integrates the product as a function of time and / or the value of the integral of the detected value as a function the time is determined, in particular from start of operation to current time step. The advantage here is that considered is that at low load, the service life of the transmission is much higher as at nominal load or even overload.

at In an advantageous embodiment, the factor is exponential Function of the torque of a gearbox. It is advantageous that a small amount of computation is necessary.

at an advantageous embodiment, the value of the load condition determined from the detected value of the angle-related quantity. Is an advantage in the process that only one value has to be recorded and from this all necessary ones Sizes determinable are.

at According to an advantageous embodiment, the detected value corresponds to a Angular velocity and the value of the load condition is the difference the angular velocity to the angular velocity at vanishing Load, in particular the difference of the angular velocity to with gear ratio and pole number of the electric motor multiplied power frequency. From The advantage here is that the slip can be used as a measure of the load is because the detection of the angular velocity is carried out anyway. So it only needs the mains frequency and the number of poles and gear ratio the evaluation unit can be entered as a parameter.

The Invention will now be explained in more detail with reference to figures:

In the 1 an inventive system is sketched schematically.

Here is a gear 8th with its drive shaft 9 and one with the output shaft 7 connected gear 6 shown. Further toothing parts and / or intermediate shafts are not shown.

On a housing cover 5 is a proximity sensor 4 mounted on the toothing of the gear 6 is arranged directed. The signal line of the sensor 4 leads outwards to an evaluation unit 1 , the display means 2 and outputs 3 includes.

In a further embodiment according to the invention, the evaluation unit 1 from a converter, in particular designed as a plug-in card.

In a further embodiment according to the invention, the evaluation unit 1 in one of a field device in a system or by a computer such as PC, in particular designed as a plug-in card.

The proximity sensor detects the protruding teeth and thus acts as an angle sensor for detecting the movement of the gear 6 usable. Alternatively, only the number of revolutions made can be determined from the signal of the sensor.

At the rotation of the gear 6 kick teeth of the gear 6 with teeth of a further toothing part in engagement, with engaged teeth transmit torque.

In the evaluation unit 1 are stored for each load condition, so value of the torque on the output shaft, maximum allowable numbers of engagement of the teeth of the two output side gear parts.

Alternatively, these quantities are corresponding quantities, such as the number of total revolutions since the start of operation, the direction of rotation need not be taken into account, or the integral of the amount of angular velocity as a function of time, the integral being determined from the start of operation. Technically substantially equivalent quantities, such as the number of revolutions at a uniform rotational speed, are also advantageously usable. The following is also for the sake of simplicity of the number of revolutions spoken instead of the sizes.

In the evaluation unit 1 In operation, the exceeding of the stored, stored in particular in a mechanical or electronic memory of the evaluation unit, the maximum permissible number is monitored and displayed when exceeding a warning or alarm and / or triggered. In particular, the evaluation unit in electronic version can be connected to a fieldbus and the warning or the alarm can be reported via this. When integrating the evaluation unit in a converter driving the electric motor supplying converter can be switched off in a particularly simple and fast manner in case of alarm, the gearbox or in a safe state.

By Connecting the outputs the evaluation unit with an electric motor driving the gearbox Serving inverter is also a simple emergency shutdown realizable. Alternatively or additionally, the outputs are also connectable with a controller, which in turn controls the drives.

Instead of of the proximity sensor Other angle sensors or revolution sensors or revolution counters are also usable.

In a further embodiment of the invention will be added to the number of revolutions the number of operating hours of the gearbox is recorded. In further embodiments will be added still detects the number of starts and / or stops of the transmission. Each of these recorded operating variables has a maximum permissible number stored in the evaluation unit. Thus, when reaching the maximum permissible Operating hours or the maximum allowed number of start or Stops a shutdown, a warning and / or an alarm can be triggered.

Furthermore is in this way already before reaching the respective maximum allowable value Number of revolutions or other sizes of Remaining residual value until reaching the maximum permissible value displayable. Thus, a predictive mode of operation is possible, because timely a maintenance date can be determined and thus triggering the Warning, the alarm or shutdown is preventable.

through The evaluation unit is thus the forecast of the remaining term until Alarm can be displayed. In particular, therefore, a scheduled maintenance of a Drive reached.

In a further embodiment of the invention the evaluation unit is loaded with parameters that refer to the Transmission, a driving this electric motor and / or a refer to this supplying converter. For example, the translation becomes a gear stage, an operating factor of the geared motor, bearing life of bearings of gearbox or electric motor, oil grade in the transmission, mains frequency of the electrical supply network and The like, deposited in the evaluation and in determining the Remaining time taken into account.

The The evaluation unit records the number of starts, ie switch-on processes.

Consequently it is also possible that the evaluation unit has a forecast of a remaining time until the Alarm due to the past operating characteristics, ie as Function of the previous gradients of the values of the sizes, executes.

In Further training becomes a maximum permissible value for each load condition assigned. Thus, for example, at very low load of the transmission, for example, far below nominal load, a larger maximum permissible Value attributable. On the other hand, at rated load is a smaller value assigned.

Becomes now the transmission with variable Operated load is used in determining the present number of revolutions each turn is a load-dependent weight factor multiplicatively added and then by summing the old value of the present number of revolutions formed the new present revolution number. Accordingly becomes the above integral as an integral part of the product of load-dependent Weight factor formed with the amount of angular velocity. The burden-dependent Weight factor is preferably an exponential function of the load.

In Training is not just a single maximum value but there are two or more to be monitored Values entered. Thus, when crossing the lowest Value is a pre-alarm and when exceeding the greatest value an alarm can be triggered.

The Evaluation unit comprises an internal memory for storing relevant Data, in particular the aforementioned parameters and values. The memory is formed or electrically supplied with a battery, that even in case of power failure of the supply network, a long-term storage the data takes place.

Furthermore, in the evaluation unit on an additional monitoring of other sizes Exceeding critical values provided. For example, an immediate alarm when exceeding or falling below critical values of the speed, the speed fluctuations, the number of starts per unit time, and the like executable. Thus, not only a remaining time is indicated but also a condition monitoring of the actual values of state variables of the drive and / or of variables derived therefrom.

In a further embodiment of the invention By means of the sensor, the average distance to the shaft or recorded to the gear and thus an evaluation of lateral force or waves or gear shift allows.

In a further embodiment of the invention will be a value for Slippage of an asynchronous motor driving the transmission is transmitted to the evaluation unit, in particular from a converter supplying these. This value for slippage is used as the above-mentioned load condition. Corresponding For converter - fed synchronous motor, the model value for torque or Power transmitted to the evaluation unit and used in an analogous manner.

at Mains-fed asynchronous motor is the difference of the rotational speed the gear under load to the load-free rotational speed, the product of the gear ratio corresponds to the mains frequency, used as a load condition.

In a further embodiment of the invention the evaluation unit is carried out purely mechanically, by electrical switching contacts, but no electronic semiconductor devices are used. Advantageously, this evaluation unit is easy to understand, robust, simple and environmentally friendly.

In a further embodiment of the invention will be added the acquisition of other parameters, such as Temperature, vibration, dust concentration, particles, and computational algorithm for the evaluation and component-specific prognosis of the remaining life, especially for example, Bearing, toothing, oil, Provided sealing ring.

In a further embodiment of the invention is used to determine the number of revolutions of the evaluation only the motor current and / or supplied to the motor voltage supplied and it will be the duty cycle, frequency, and / or load condition evaluated.

In a further embodiment of the invention are no drive or gearbox specific parameters in the Evaluation unit deposited but only a maximum allowed number of revolutions, when they are exceeded an alarm is triggered becomes. The stored maximum permitted value is the number of revolutions to choose such that it is adapted to the existing circumstances, in particular the drive and / or the transmission.

1

evaluation

2

display means

3

outputs

4

Proximity sensor

5

housing cover

6

gear

7

output shaft

8th

transmission

9

drive shaft

Claims (14)

System comprising at least one gear driven by an electric motor and an evaluation unit, wherein a sensor for detecting an angle-related quantity, such as number of revolutions, angle and / or angular velocity of a shaft of the transmission, characterized in that the evaluation unit comprises comparing means, on the one hand a value stored in a memory of the evaluation unit is supplied and on the other hand a value determined from the sensor signals is supplied, the comparison means being connected on the output side to at least one output of the evaluation unit and / or display means of the evaluation unit, in particular for displaying a remaining operating hours number, a residual rotation number, an alarm and / or a warning. System according to at least one of the preceding Claims, characterized in that the sensor is an inverter, wherein this means for detecting motor current and / or motor voltage and means for forming model values which the evaluation unit, in particular by means of an electrical or wireless connection, supplied become. System according to at least one of the preceding Claims, characterized in that the sensor is a proximity sensor, in particular a on a housing part gearbox mounted proximity sensor. System according to at least one of the preceding claims, characterized in that the evaluation unit is designed as a plug-in card, in particular a computer, a Um judge or a field device. System according to at least one of the preceding Claims, characterized in that the sensor teeth of a toothing part detected, in particular the removal and / or the passing the teeth. System according to at least one of the preceding Claims, characterized in that means for determining the load condition the transmission or geared motor are connected to the evaluation unit. System according to at least one of the preceding Claims, characterized in that the sensor also serves as a means for determining the load condition acts Method for determining a remaining number of hours of operation, a residual number of revolutions, an alarm and / or a warning in which an angle-related size, like Number of revolutions, angle and / or angular velocity of a Wave or the like, is detected, characterized, that a value from the detected values of the angle-related quantity for operating hours, The number of revolutions is determined and this particular value with a value stored in a memory is compared, in particular in every time step, where when exceeding or falling below the stored value triggers a warning and / or an alarm, especially being from the difference of the given value and the deposited value a value for remaining operating hours and / or remaining revolution number is determined and displayed. Method according to at least one of the preceding Claims, characterized in that from the detected values of the angle-related quantity, a value for operating hours, Number of revolutions is determined by the amount of the detected value is integrated as a function of time and / or the value of the integral the detected value is determined as a function of time, in particular of Start of operation until the current time step. Method according to at least one of the preceding Claims, characterized in that from the detected values of the angle-related quantity, a value for operating hours, Rotation speed is determined, taking into account the load condition is and where for different values of the load state various deposited Values are used. Method according to at least one of the preceding Claims, characterized in that from the detected values of the angle-related quantity, a value for operating hours, Number of revolutions is determined by the amount of the detected value multiplied by a load state dependent factor associated with each time step and the product is integrated as a function of time and / or the value of the integral of the sensed value as a function of time is determined, in particular from start of operation to the current Time step. Method according to at least one of the preceding Claims, characterized in that the factor is an exponential function is the torque of a transmission. Method according to at least one of the preceding Claims, characterized in that the value of the load condition the detected value of the angle-related quantity is determined. Method according to at least one of the preceding Claims, characterized in that the detected value corresponds to an angular velocity and the value of the load condition is the difference of the angular rate to the angular velocity at vanishing load, in particular the difference of the angular velocity to with gear ratio and pole number of the electric motor multiplied power frequency.