Sensor Unit for Motor-Driven Gate Position Control
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Solution Overview
Problem
Existing sensor units for motor-driven gates are often integrated into complex and expensive drive systems, making them costly and difficult to retrofit into existing systems, especially when using sensorless drives.
Innovation Solution
A sensor unit with its own housing that can be independently mounted on the drive shaft, allowing for a space-saving and flexible installation, using a gear stage with a worm gear to convert the drive shaft's revolutions into position sensor revolutions, and including a position sensor and pulse disk for precise position and speed detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the position sensor is integrated into the drive unit, then the control function is achieved, but the device complexity and cost increase
Solution Approach 1:
The sensor unit is separated from the drive unit into an independent module with its own housing. This segmentation allows the sensor to be mounted separately on the drive shaft, reducing the complexity of the drive system while maintaining the control function. The sensor unit can be retrofitted to existing sensorless drives without replacing the entire drive system.
Solution Approach 2:
The position sensor is extracted from the drive unit and mounted independently on the drive shaft. This extraction eliminates the need for complex integrated sensor drives and allows the use of simple sensorless drives, reducing both complexity and cost while achieving the same control objective.
2Reliability
If the sensor unit is mounted on the drive shaft, then the position control is achieved, but the space for installation is reduced
Solution Approach 1:
The sensor unit is designed with a housing that fits around the drive shaft, utilizing the existing space along the shaft. The gear stage is arranged concentrically with the drive shaft, and the position sensor is mounted in the available radial space, creating a compact nested arrangement that minimizes the overall volume required for installation.
Solution Approach 2:
The sensor unit utilizes the axial dimension of the drive shaft for mounting, arranging components along the length of the shaft rather than requiring additional radial or longitudinal space. This dimensional approach allows compact installation in limited spaces while maintaining full position control functionality.
3Ease of manufacture
If existing sensorless drives are used, then the cost is reduced, but the position detection capability is lost
Solution Approach 1:
The sensor unit acts as an intermediary between the drive shaft and the control system. It includes a gear stage that converts the rotational motion of the drive shaft into appropriate signals for the position sensor, enabling position detection when used with simple sensorless drives. This intermediary module provides the necessary measurement capability without requiring complex integrated drives.
4Measurement precision
If the gear stage has high reduction ratio, then the position sensor revolutions are optimized, but the device complexity increases
Solution Approach 1:
The gear stage uses a worm gear mechanism which provides high reduction ratio with a simple single-stage design. This mechanical substitution achieves the optimized revolution count for the position sensor without requiring complex multi-stage gear trains, thereby maintaining low device complexity while achieving precise measurement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the use of inexpensive standard drives and easy retrofitting of existing systems without replacing the drive unit, providing precise position control and adaptable installation even in limited spaces, while allowing for modern control upgrades.
Implementation Method 1
The gear stage of the sensor unit (1) advantageously has a worm gear. Such a worm gear is a simple and space-saving way of converting the revolutions of the drive shaft of the gate into a reduced number of revolutions of the position sensor
Implementation Method 2
A reference point disk is usually used here, the rotation of which is coupled to the rotation of the drive shaft via the gear stage. Reference points are arranged on the reference point disc, which are recognized by sensors when the disc moves past them.
Implementation Method 3
the sensor unit according to the invention also comprises a device for detecting the rotational speed of the drive shaft, in particular a pulse disk. Such a pulse disk, which is also coupled to the rotation of the drive shaft, generates pulses in connection with a corresponding sensor when the drive shaft moves
Data Source
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AI summary
The present invention relates to a sensor unit (1) for determining the position of a motor-driven gate, comprising a position sensor (6) and a gear stage for connecting the position sensor (6) to the drive shaft (3) of the gate, wherein the sensor unit (1) has its own housing (4, 14) so that it can be mounted independently of the drive unit (2) of the gate.