Brushless Parking Lock Actuator With Compact Worm Gear Layout
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Solution Overview
Problem
Existing actuators for vehicle gearbox parking locks face issues with brushed electric motors sticking during inactivity and require compact, lightweight designs that current solutions fail to meet.
Innovation Solution
A brushless DC electric motor actuator with a reduction mechanism, two electronic boards, and a worm gear arrangement, housed in a lightweight plastic or metal casing, ensuring efficient control and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a brushed electric motor is used in the actuator, then the motor can provide sufficient torque for the parking lock system, but the brushes tend to stick to the commutator during extended periods of inactivity, leading to degraded actuator performance
Solution Approach 1:
The patent removes the brushes and commutator components from the motor design by switching to a brushless DC motor topology. This extraction of the problematic components eliminates the brush-sticking issue entirely while maintaining the motor's torque output capability for the parking lock system.
Solution Approach 2:
The patent replaces the mechanical brush-commutator contact system with an electronic commutation system using Hall effect sensors and electronic control circuitry. This substitution eliminates mechanical wear and sticking issues while providing precise control of the motor's rotational output for the parking lock mechanism.
2Weight of moving object
If the actuator is designed to be compact and lightweight, then it meets the important criterion for car manufacturers, but integrating multiple components (electric motor, reduction mechanism, two electronic boards) into a single unit increases design complexity
Solution Approach 1:
The patent combines the electric motor, reduction mechanism with worm gear and toothed wheel, and both electronic boards into a single integrated actuator unit with a unified housing. This merging reduces the overall number of separate components, simplifies installation, and decreases total weight while maintaining all necessary functions for the parking lock system.
Solution Approach 2:
The patent nests the electronic boards within the housing of the actuator unit, positioning them in available spaces around the motor and reduction mechanism. The first electronic board is positioned near the motor and the second electronic board is integrated into the reduction mechanism assembly, allowing compact arrangement of all components within the single actuator housing.
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
The solution eliminates brush-related issues and provides a compact, efficient actuator for vehicle gearbox parking locks, maintaining performance and reducing weight.
Implementation Method 1
The electric motor is a brushless DC type and comprises a stator provided with three-phase stator coils and a rotor provided with permanent magnets
Implementation Method 2
The device for determining the position of the rotor of the electric motor comprises at least one phase sensor, preferably three sensors, located opposite the multi-pole magnet to ensure electronic switching of the power supply to the stator windings
Data Source
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AI summary
The present invention relates to an actuator for a parking lock system of a vehicle gearbox, said actuator (1) comprising: an electric motor (20) provided with stator coils, a rotor and an output shaft (23) connected to the rotor and extending along an X-axis; and a reduction gear mechanism (70) having a torque output element (31) that is rotatable so as to be able to turn between a locked position and a released position, said reduction gear mechanism (70) being kinematically linked to the output shaft (23) of the electric motor (20), the electric motor (20) being of the brushless DC type and the actuator (1) comprising a first electronic board (50) and a second electronic board (40), said second electronic board (40) comprising a device for determining the position of the rotor of the electric motor (20).