Brushless Wobble Rotor Pump for Low-Vibration Handheld Sprayers
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Solution Overview
Problem
Hand-held hydraulic fluid devices with integrated motor-pump groups suffer from increased weight and vibrations, leading to reduced fatigue-free operation and handling efficiency compared to devices with separate base units.
Innovation Solution
The use of a brushless direct current motor paired with a wobble rotor pump featuring two toothed disks with differing spur gear teeth, arranged at an angle, which reduces vibrations and weight, and includes a design where the motor faces the liquid outlet for optimal weight distribution and cooling, and the pump is designed to be self-priming and pulsation-free.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the motor-pump group is integrated into the hand-held device, then the device becomes self-contained and portable, but the weight increases significantly
Solution Approach 1:
The device is divided into modular components: a hand-held unit containing the motor-pump group and nozzle, and a separate base unit with fluid reservoir. This segmentation allows the hand-held portion to be lightweight and portable while the heavier components remain in the base unit.
Solution Approach 2:
The contradiction is resolved by transitioning from a fully integrated single-unit design to a distributed two-unit system. The hand-held device operates independently from the base unit via a pressure hose, effectively moving the weight burden to a separate spatial location rather than concentrating it in the hand-held portion.
2Ease of operation
If the motor-pump group is integrated into the hand-held device, then the device is self-contained, but vibrations increase and reduce fatigue-free operation time
Solution Approach 1:
By separating the motor-pump group from the fluid reservoir into different units, the vibratory components are isolated in the hand-held unit while the base unit remains stationary, reducing the transmission and amplification of vibrations during operation.
Solution Approach 2:
The motor is designed as a brushless DC motor with optimized rotational speed and torque characteristics, and the pump uses a wobble rotor mechanism with toothed disks that differ by one tooth, creating a balancing effect that reduces vibration amplitude during operation.
3Stress or pressure
If axial piston pumps are used in hand-held devices, then high pressure delivery is achieved, but vibrations and oscillations are high
Solution Approach 1:
Instead of using a conventional axial piston pump design, the patent implements a wobble rotor pump with toothed disks that replicates the high-pressure pumping function through a different mechanical mechanism, achieving similar pressure output with reduced vibration.
Solution Approach 2:
The pump design uses two toothed disks where the number of teeth differs by exactly one, creating a phasing relationship that balances the pumping chambers and reduces pressure pulsations and associated vibrations while maintaining high-pressure capability.
4Duration of action of moving object
If a heavier battery is used to extend operating time, then fatigue-free operation duration increases, but device weight increases
Solution Approach 1:
The power source (battery) is integrated into the hand-held unit with optimized capacity to provide sufficient operating time for typical applications, while the heavier fluid reservoir is placed in the separate base unit, effectively distributing the weight burden across two locations.
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 provides a hand-held hydraulic fluid device with significantly reduced vibrations and weight, enabling longer fatigue-free operation, stable fluid delivery across various throughputs, and the ability to apply finely atomized mist, with improved handling and operational efficiency.
Implementation Method 1
the motor of the motor-pump group is designed as a brushless DC motor
Implementation Method 2
the pump as a wobble rotor pump with two toothed disks, each having an annular spur gearing. The number of teeth of the two meshing spur gears differs by 1
Implementation Method 3
the vibrations and oscillations induced by the motor-pump assembly are substantially lower than in state-of-the-art devices
Implementation Method 4
the pump used according to the invention is reliably self-priming
Data Source
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AI summary
A manually operated pressure fluid device comprises a housing structure (1) which receives a motor-pump group (4) and has a fluid inlet (8) connected to the pump (6) on the intake side and a fluid outlet (9) formed on a nozzle unit (10) and connected to the pump (6) on the delivery side, an electrical power source (14) and at least one control element (12) acting on the power supply of the motor (5) via the power source (14). The motor (5) of the motor-pump group (4) is designed as a brushless direct current motor (33) and the pump is designed as a whirling rotor pump (16) having two lock washers, each having an annular face spline, wherein the number of teeth of the two face splines intermeshing with each other differ from each other by one and the lock washers arranged at an angle relative to each other wander relative to each other such that the face splines delimit a plurality of pump chambers which increase and reduce in size during pump operation.