Motor Drive Unit Asymmetric Brake Layout for Weight Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional motor drive units for electric vehicles face challenges in maintaining weight balance due to the larger size and weight of the drive motor, which disrupts the vehicle's lateral weight distribution, and require additional components like brake calipers and hydraulic systems.
Innovation Solution
A motor drive unit design featuring a dual differential unit with a torque reversing mechanism and an inboard brake system, where the brake device is positioned on the opposite side of the drive motor across the output shaft, allowing for balanced weight distribution and eliminating the need for hydraulic systems and reinforcements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the drive motor is disposed on one side of the vehicle to transmit torque to the input gear, then the torque transmission is achieved, but the lateral weight balance of the vehicle is disrupted
Solution Approach 1:
The patent employs asymmetric arrangement of heavy components within the motor drive unit. The drive motor is positioned on one side while the brake device is positioned on the opposite side, creating an asymmetric internal layout that balances the overall weight distribution. This asymmetric configuration allows the heavy drive motor and heavy brake device to counterbalance each other laterally, resolving the weight balance issue while maintaining effective torque transmission.
2Adaptability or versatility
If an electromagnetic brake is incorporated into the motor drive unit, then the motor drive unit can serve as an inboard brake and hydraulic systems may be omitted, but the device complexity increases
Solution Approach 1:
The patent merges the brake device directly into the motor drive unit structure, combining the functions of torque transmission and braking into a single integrated assembly. The brake device is positioned on the opposite side of the drive motor within the same housing, and both components share the common housing structure. This merging eliminates the need for separate brake calipers and hydraulic systems, reducing overall system complexity while providing inboard brake functionality.
3Weight of moving object
If the brake device is disposed on the opposite side of the drive motor across the output shaft, then the lateral weight distribution is balanced, but the space arrangement becomes more constrained
Solution Approach 1:
The patent utilizes the radial dimension of the output shaft to arrange components. By positioning the drive motor and brake device on opposite sides across the output shaft in a radial configuration, the design achieves lateral weight balance while efficiently utilizing the available space. This dimensional arrangement allows both heavy components to be compactly positioned around the central output shaft without requiring excessive lateral space.
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 design achieves balanced lateral weight distribution, reduces unsprung load, and enables a compact, lightweight motor drive unit with enhanced design flexibility, while also functioning as an inboard brake capable of stopping the vehicle without external power.
Implementation Method 1
a brake device (4) that stops rotation of the drive gear (24) fitted onto the output shaft (9) by engaging at least one rotary member (28) rotated integrally with the output shaft (9) with at least one brake member (29) that is allowed to rotate relatively to the rotary member (28) but restricted to rotate in a rotational direction of the rotary member (28)
Data Source
AI summary
A motor drive unit having an inboard brake in which a lateral weight distribution is balanced is provided. In the motor drive unit, output torque of a drive motor is distributed to a right driveshaft and a left driveshaft via a drive gear a drive gear fitted onto an output shaft thereof. A brake rotor is also fitted onto the output shaft to be rotated integrally therewith. A brake device stops rotation of the drive gear by engaging the brake rotor with a brake stator that is allowed to rotate relatively to the brake rotor but restricted to rotate in a rotational direction of the brake rotor. The brake device is disposed on an opposite side of the drive motor across the drive gear.