Brushless Motor Controller for Compact Electric Pump

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Solution Overview

Problem

Conventional electric pump devices used in vehicles to supply oil to continuously variable transmissions are enlarged in size due to the need for a relief valve to prevent loss of synchronism in brushless motors, which contradicts the demand for reduced vehicle component size.

Innovation Solution

An electric pump device that controls the power supply to the brushless motor to stop and restart it when synchronism loss is detected, using induced voltage comparisons to determine synchronism loss without a relief valve, allowing for continuous hydraulic pressure application and reducing device size by eliminating the need for a position sensor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a relief valve is added to prevent loss of synchronism of the brushless motor, then the reliability is improved, but the device complexity increases and the size is enlarged

Engineering Contradiction:

Improveprevention of loss of synchronismVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical relief valve with an electronic control system that monitors motor current and voltage to detect loss of synchronism. The controller electronically manages the brushless motor operation, eliminating the need for mechanical pressure relief components and reducing overall device complexity while maintaining reliability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback mechanism where the controller continuously monitors the operational state of the brushless motor and adjusts power supply accordingly. This closed-loop control detects loss of synchronism through electrical parameters and automatically responds, replacing the passive mechanical relief valve approach with an active electronic feedback system

Inventive Principle:

Principle #23Feedback

2Reliability

If a relief valve is added to prevent loss of synchronism of the brushless motor, then the reliability is improved, but the volume increases

Engineering Contradiction:

Improveprevention of loss of synchronismVSAvoiddevice size

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The controller serves multiple functions: it controls the brushless motor operation, detects loss of synchronism through electrical parameter monitoring, and manages power supply adjustments. This multi-functional approach eliminates the need for separate relief valve components, reducing device volume while maintaining reliability

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If the brushless motor is restarted after loss of synchronism, then the productivity is improved by continuous oil supply, but the reliability may be affected by repeated start-stop cycles

Engineering Contradiction:

Improvecontinuous oil supplyVSAvoidmotor reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements periodic monitoring and control of the brushless motor operation. The controller continuously detects operational parameters and performs periodic adjustments to maintain synchronism, enabling rapid restart capability that minimizes interruption to oil supply while managing motor stress through controlled cycling

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent prepares for potential loss of synchronism by maintaining readiness to restart the motor quickly. The control system keeps the motor in a state where rapid重新启动 is possible, and the hydraulic system is designed to handle pressure variations during restart, ensuring continuous oil supply capability while managing reliability concerns

Inventive Principle:

Principle #10Preliminary action

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 enables a compact electric pump device to continuously apply hydraulic pressure to hydraulic devices by stopping and restarting the brushless motor to manage hydraulic pressure, eliminating the need for a relief valve and position sensor, thus reducing the device's size and maintaining efficient operation.

Implementation Method 1

an oil pump (5), a brushless motor (6) that drives the oil pump (5), and a controller (7) that controls the brushless motor (6)

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

supplies oil to a continuously variable transmission (CVT) or a power steering device of a vehicle

Methodology Applied

Scientific EffectHydraulic pressure: Pressure Gradient

Data Source

PatentEP2282402B1Electric pump device

Publication Date: 2020.09.02 JTEKT CORP

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Figure 3(a)~3(b)

AI summary

An electric pump device is provided that continuously applies hydraulic pressure to a hydraulic device and is reduced in size. An electric pump device P includes an oil pump 5 that supplies oil to a continuously variable transmission, a brushless motor 6 that drives the oil pump 5, and a controller 7 that controls the brushless motor 6. The controller 7 has a power supply section 71 that supplies drive power to the brushless motor 6 and a synchronism loss determining section 73 that determines whether the brushless motor 6 has lost synchronism. The controller 7 has a drive control section 72 that controls the power supply section 71 to start the brushless motor 6 after controlling the power supply section 71 to stop supply of the power to the brushless motor 6 when the synchronism loss determining section 73 determines that the brushless motor 6 has lost synchronism.