Hub Motor Arrangement Using Planetary Gear Transmission
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Solution Overview
Problem
Existing hub motor arrangements are too expensive and heavy for use in children's vehicles, making them unsuitable for providing a desirable operating experience at a reasonable cost.
Innovation Solution
A hub motor arrangement that utilizes a standard, commercially-available 'off-the-shelf' electric motor with a planetary gear transmission system, where the motor is positioned along the axis of rotation and offset laterally within a housing that supports the motor and transmission components, allowing for a compact and cost-effective design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a custom or large electric motor arrangement is used in a hub motor, then the power and performance are improved, but the weight and cost increase significantly
Solution Approach 1:
The patent combines a standard off-the-shelf electric motor with a planetary gear transmission system into an integrated hub motor assembly. This merging allows the use of a smaller, lighter motor while achieving the required power output through mechanical advantage from the gear system, thereby reducing overall weight while maintaining power performance.
Solution Approach 2:
The planetary gear transmission acts as an intermediary between the motor and the wheel hub. It transforms the high-speed, low-torque motor output into low-speed, high-torque wheel rotation, enabling a smaller motor to deliver the same effective power to the wheel, thus reducing motor size and weight.
2Power
If a custom or large electric motor arrangement is used in a hub motor, then the power and performance are improved, but the cost increases significantly
Solution Approach 1:
The patent employs a universal, off-the-shelf electric motor that can be sourced from standard manufacturers rather than requiring custom-built motors. This universal component approach significantly reduces cost while the planetary gear system provides the necessary power multiplication, achieving the same performance at lower manufacturing cost.
Solution Approach 2:
The invention substitutes expensive custom motors with inexpensive, commercially available standard motors. While standard motors may have shorter operational life in demanding applications, for children's vehicles this provides cost-effective performance, and the motors can be easily replaced if needed.
3Ease of manufacture
If a standard off-the-shelf motor is used, then the cost is reduced, but the motor occupies more space relative to the wheel hub
Solution Approach 1:
The patent nests the planetary gear transmission system around the motor shaft, with planet gears arranged radially around the sun gear which is connected to the motor output. This nested configuration maximizes space utilization, allowing the gear system to fit within the minimal additional volume required, thus keeping the overall hub motor compact despite using standard components.
Solution Approach 2:
The planetary gear system utilizes the radial dimension by arranging planet gears around the central sun gear, effectively distributing components in three-dimensional space rather than linearly. This dimensional arrangement allows compact packaging of the transmission system around the motor, minimizing the overall volume occupied by the hub motor assembly.
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 design provides a lightweight, cost-effective hub motor arrangement that offers equivalent power to traditional hub motors, with improved efficiency and longer battery life due to reduced amperage draw, while maintaining a balanced and efficient structure.
Implementation Method 1
A planetary gear transmission system, where the motor is positioned along the axis of rotation and offset laterally within a housing that supports the motor and transmission components
Implementation Method 2
A sun gear is driven by a motor
Data Source
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AI summary
A ride-on vehicle, such as for a child, includes a vehicle body and one or more wheels that support the vehicle body relative to a surface. At least one of the wheels includes a hub motor arrangement that provides a drive torque for propelling the vehicle. The hub motor arrangement includes a housing defining an interior space. An axle or other mounting element(s) define an axis of rotation of the housing. Preferably, the axle or other mounting element(s) do not pass completely through the housing. A motor drives the housing through a transmission. Preferably, the motor is a standard, compact motor that is positioned on the axis of rotation and can be laterally offset from a central plane of the housing. In some embodiments, a traction element is carried directly by the housing.