Rail Vehicle Windscreen Wiper Drive Using Disk Motor and Planetary Gear

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Solution Overview

Problem

Existing windshield wiper drives for rail vehicles face challenges in achieving high dynamics and torque while maintaining a small structural size, and they often require complex mechanical transmission systems that are prone to wear and vibration.

Innovation Solution

The use of a disk motor with planetary gearing, which combines a compact ironless rotor and high-efficiency planetary gearing to provide a rigid drive train with minimal mechanical components, reducing wear and enhancing vibration resistance, along with a contactless rotational angle sensor for precise position control and a mechanical rotational angle delimiter for safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a conventional motor with mechanical transmission system is used, then torque can be achieved, but the structural size increases and dynamics decrease

Engineering Contradiction:

ImprovetorqueVSAvoidstructural size

Core Design Contradiction:

PowerVSVolume of moving object

Solution Approach 1:

The patent merges the motor and transmission system into a single integrated unit. The planetary gearing is directly coupled to the motor shaft, eliminating the need for separate transmission components and reducing overall structural size while maintaining torque output.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The planetary gearing mechanism is nested within the motor housing. The sun gear is mounted on the motor shaft, planet gears orbit around it, and the ring gear forms the outer boundary, creating a compact nested structure that delivers high torque in a small volume.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Power

If a complex mechanical transmission system is used, then torque can be achieved, but wear and vibration increase

Engineering Contradiction:

ImprovetorqueVSAvoidwear resistance

Core Design Contradiction:

PowerVSReliability

Solution Approach 1:

The patent replaces complex multi-stage mechanical transmission with a single-stage planetary gearing system. This simplified mechanical system has fewer moving parts, reduced friction points, and lower vibration levels while maintaining effective torque transmission.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and eliminates unnecessary intermediate transmission components from the drive system. By using direct coupling between the motor and planetary gear input, it removes belts, chains, or multiple gear stages that would contribute to wear and vibration.

Inventive Principle:

Principle #2Taking out (Extraction)

3Speed

If high dynamics are achieved, then rapid wiping movements are enabled, but torque may be reduced

Engineering Contradiction:

ImprovedynamicsVSAvoidtorque

Core Design Contradiction:

SpeedVSPower

Solution Approach 1:

The patent employs an ironless rotor construction that eliminates magnetic hysteresis losses and mechanical commutator friction, enabling rapid acceleration and deceleration. The rotor can be magnetically braked when energized, providing dynamic control while maintaining high torque capability through the planetary gearing multiplication effect.

Inventive Principle:

Principle #15Dynamics

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

This configuration achieves high torque and dynamic performance with reduced structural size, extended service life, and improved reliability by minimizing axial forces and brush wear, while allowing precise control of the windshield wiper arm's position.

Implementation Method 1

the electric motor is formed by a disk motor... Owing to the construction of a disk motor, the latter exhibits high dynamics... Owing to the generally ironless rotor, no or only little brush sparking occurs

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the gearing may be formed by a planetary gearing... the input shaft of which can be connected to an output shaft of the motor

Methodology Applied

Scientific EffectMechanical advantage through planetary gear mechanism: Epicyclic Gearing

Implementation Method 3

a contactless rotational angle sensor for precise position control

Methodology Applied

Scientific EffectContactless rotational angle detection:

Data Source

PatentUS10843665B2Windscreen wiper drive of a windscreen wiper device of a rail vehicle

Publication Date: 2020.11.24 KNORR BREMSE GMBH

AI summary

Disclosed embodiments relate to a windscreen wiper drive of a windscreen wiper device of a rail vehicle. The drive includes at least one electric motor, a gear, the input shaft of which being connected to an output shaft of the electric motor, wherein an output shaft of the gear is provided for driving at least one windscreen wiper arm of a windscreen wiper, which arm swings back and forth with the output shaft, a rotation angle sensor unit, which detects a rotation of at least one element of the windscreen wiper drive, and a mechanical rotation angle limitation, which mechanically limits a rotational movement of at least one element of the windscreen wiper drive. The electric motor is formed by a disc motor and the gear is formed by a planetary gear.