Vehicle Pump Gear Mechanism With Reversible Transmission Ratios
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Solution Overview
Problem
Existing pump devices for motor vehicles lack efficiency and compactness in operation, particularly in switching between transmission ratios and managing dynamic loads, which affects their performance and stability.
Innovation Solution
A pump device with a single-stage or multi-stage gear mechanism that couples the electric drive's output shaft to a rotor or pump housing, allowing switching between transmission ratios by reversing the electric drive's rotation direction, and incorporating a planet carrier fixed to the drive housing and oppositely directed freewheels to reduce dynamic loads and enhance compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a pump device uses a conventional gear mechanism with a rotating planet carrier to switch between transmission ratios, then switching between different transmission ratios is possible, but the device becomes more complex and dynamic loads increase
Solution Approach 1:
The patent extracts the planet carrier from the rotating components and fixes it to the drive housing. This removes the complex rotating planet carrier mechanism while maintaining the ability to switch between transmission ratios through the freewheels, thereby reducing device complexity while preserving adaptability.
Solution Approach 2:
Instead of using a rotating planet carrier to achieve transmission ratio switching, the patent inverts the approach by fixing the planet carrier and using freewheels to achieve the same switching function. This inversion simplifies the overall mechanism by eliminating the need for a rotating planet carrier.
2Adaptability or versatility
If a pump device uses a conventional gear mechanism with a rotating planet carrier to switch between transmission ratios, then switching between different transmission ratios is possible, but dynamic loads and unbalances increase
Solution Approach 1:
By extracting the planet carrier from the rotating components and fixing it to the drive housing, the patent eliminates the source of dynamic unbalances associated with rotating planet carriers. This maintains transmission ratio switching capability through freewheels while significantly reducing dynamic loads and improving reliability.
3Adaptability or versatility
If the pump housing is rotatable relative to the drive housing to create a differential pump, then variable operating points can be achieved, but the device becomes less compact and stable
Solution Approach 1:
The patent extracts the ability to achieve variable operating points from the mechanical rotation of the pump housing and instead implements it through the gear mechanism with freewheels. The pump housing remains fixed, providing stability, while the transmission ratio switching through freewheels enables variable operating points.
4Volume of moving object
If the pump device is designed to be compact, then space is saved, but the gear mechanism becomes more complex
Solution Approach 1:
By removing the rotating planet carrier and fixing it to the drive housing, the patent reduces the spatial requirements and complexity of the gear mechanism. The compact design is achieved through this simplification while maintaining transmission ratio switching capability through the freewheel mechanism.
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
Enables efficient operation with different transmission ratios, reducing dynamic loads and achieving a more compact design, allowing for variable operating points with low delivery pressure and high volume or high delivery pressure and low volume, and supporting energy-saving and compact operation in motor vehicle transmissions.
Implementation Method 1
a single-stage or multi-stage gear mechanism which (rotationally) couples the output shaft of the electric drive to the first pump member
Implementation Method 2
oppositely directed freewheels which reduce dynamic loads
Data Source
AI summary
A pump device for a motor vehicle includes: a pump having a first pump member and a second pump member, the first and second pump members being movable relative to one another; an electric drive having a drive housing and an output shaft rotatable with respect to the drive housing; and a gear mechanism, which couples the output shaft to the first pump member and, by reversing a direction of rotation of the electric drive, is switchable between a first and an opposite second transmission ratio. The gear mechanism has: a planet stage having a planet carrier rotationally fixed relative to the drive housing, and/or first and second freewheels, oppositely directed with respect to one another, and which are arranged axially behind one another, and/or the second pump member has a drive shaft rotatable relative to the output shaft.