Pump Port Plate Pressure Control via Rotating Piston

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional swashplate-type pumps with variable displacement require expensive and difficult-to-control actuators for tilt angle adjustment, which can be slow to respond and costly to manufacture.

Innovation Solution

A pump design featuring a port plate with a protrusion that is rotated by a piston to adjust swivel torque, allowing for controlled tilt angle adjustment without the need for conventional swashplate-engaging actuators, using a biasing piston and actuator piston to selectively rotate the port plate and change the effective displacement of plungers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional actuators are used to control swashplate tilt angle, then the pump can achieve variable displacement, but the actuators become expensive, difficult to control, and slow to respond

Engineering Contradiction:

Improvevariable displacement capabilityVSAvoidactuator complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces a port plate as an intermediary component between the pistons and the swashplate. The port plate receives rotational input from pistons and converts it into swivel torque that acts on the swashplate, mediating the control action and simplifying the overall actuation mechanism while maintaining variable displacement capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces conventional complex actuators with a simpler piston-port plate mechanism. Instead of using traditional actuator systems that directly engage the swashplate, the invention uses pistons rotating the port plate to generate swivel torque, substituting a simpler mechanical system for a complex one

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If arcuate pistons and chambers are used as in the '905 patent, then swivel torque can be controlled, but the components become difficult and expensive to fabricate

Engineering Contradiction:

Improveswivel torque controlVSAvoidfabrication difficulty

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

Instead of using arcuate (curved) pistons and chambers as in the prior patent, the invention inverts the approach by using straight cylindrical pistons with simple circular cross-sections. The control function is achieved through the port plate's geometry and its interaction with the straight pistons, making components much easier and less expensive to fabricate while maintaining swivel torque control capability

Inventive Principle:

Principle #13The other way round (Inversion)

3Use of energy by moving object

If swashplate tilt angle is reduced to lower power consumption, then energy efficiency improves, but flow rate and pressure output decrease

Engineering Contradiction:

Improvepower consumptionVSAvoidflow rate and pressure

Core Design Contradiction:

Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent implements dynamic control of the port plate angle, allowing the system to adjust the swivel torque and swashplate tilt angle in real-time based on operational demands. This dynamic adjustment capability enables the pump to optimize between power consumption and output performance, maintaining efficiency while meeting varying flow and pressure requirements

Inventive Principle:

Principle #15Dynamics

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 simplifies tilt angle control, reduces manufacturing complexity and cost, and enhances responsiveness, providing efficient fluid flow and pressure regulation while minimizing power consumption.

Implementation Method 1

at least one piston disposed within the housing and configured to selectively engage the protrusion of the port plate to rotate the port plate and adjust the swivel torque

Methodology Applied

Scientific EffectMechanical Force: Force

Implementation Method 2

Each plunger reciprocates within an associated barrel as the plungers rotate relative to the tilted engagement surface of the swashplate. When the plunger is forced back into the barrel by the plunger engagement surface of the swashplate, the plunger pushes fluid from the barrel at an elevated pressure

Methodology Applied

Scientific EffectHydraulic Pressure: Pressure Increase

Data Source

PatentUS8790091B2Pump having port plate pressure control

Publication Date: 2014.07.29 CATERPILLAR INC

AI summary

A pump is disclosed. The pump may have a housing, a body rotatably disposed within the housing and at least partially defining a plurality of barrels, a plurality of plungers associated with the plurality of barrels, and a swashplate tiltable by a swivel torque to vary a displacement of the plurality of plungers relative to the plurality of barrels. The pump may also have a port plate with an inlet port, a discharge port, and a protrusion. The port plate may be configured to engage an end of the rotatable body. The pump may further have at least one piston disposed within the housing and configured to selectively engage the protrusion of the port plate to rotate the port plate and adjust the swivel torque.