Swash Plate Pump Regulator With Signal-Pressure Spool Biasing

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Solution Overview

Problem

Existing fluid pressure piston pumps/motors face challenges in achieving diverse control characteristics while maintaining a compact size due to the need for multiple biasing configurations on the control spool, leading to increased size.

Innovation Solution

Incorporating a biasing member that exerts force against the control spool and an accommodating chamber connected to a signal pressure, allowing for improved control characteristics without enlarging the pump/motor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple biasing configurations are provided for the control spool to achieve diverse control characteristics, then the degree of design freedom for control characteristics is improved, but the size of the fluid pressure rotating machine increases

Engineering Contradiction:
Improvecontrol characteristicsVSAvoidsize
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines multiple biasing functions into a single integrated regulator assembly. The regulator includes a biasing member (spring) that provides biasing force, and an auxiliary biasing member that receives signal pressure to provide additional biasing force against the control spool. This merging of multiple biasing configurations into one compact regulator unit achieves diverse control characteristics without proportionally increasing the overall machine size.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The regulator assembly serves multiple functions: it controls hydraulic pressure to the large-diameter piston, provides biasing force through the biasing member, and responds to signal pressure through the auxiliary biasing member. This multi-functional design allows a single component to achieve diverse control characteristics while maintaining compact dimensions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a plurality of configurations for biasing the control spool are provided to improve control characteristics, then the degree of freedom for control characteristics is improved, but the device complexity increases

Engineering Contradiction:
Improvecontrol characteristicsVSAvoidstructure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple biasing configurations are merged into a single regulator assembly rather than being implemented as separate components. The regulator integrates the biasing member, auxiliary biasing member, and control spool into one cohesive unit, reducing overall structural complexity while maintaining the ability to provide diverse control characteristics.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The regulator assembly acts as an intermediary device that mediates between the hydraulic system and the control spool. It receives hydraulic pressure and signal pressure, processes these inputs through the biasing members, and outputs controlled pressure to the large-diameter piston, simplifying the overall system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enhances control flexibility while maintaining a compact design by balancing forces on the control spool, thereby optimizing performance and reducing size constraints.

Implementation Method 1

a biasing member (51a, 51b) configured to be extended and compressed by following tilting of the swash plate (8)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

an auxiliary biasing member configured to exert a biasing force to the control spool against the biasing force exerted by the biasing member

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

a signal pressure is guided to the accommodating chamber, the signal pressure exerting a thrust force to the control spool against the biasing force exerted by the biasing member

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 4

a control spool configured to adjust the control pressure by being moved in response to biasing force exerted by the biasing member

Methodology Applied
Scientific EffectForce balance: Force

Data Source

PatentEP4431735B1Hydraulic rotary machine
Publication Date: 2026.02.25 KYB CORP
  • EP4431735B1 patent drawingFigure 1
  • EP4431735B1 patent drawingFigure 2
  • EP4431735B1 patent drawingFigure 3

AI summary

The piston pump 100 includes: a first biasing part 20 configured to bias a swash plate 8 in accordance with supplied control pressure; a second biasing part 30 configured to bias the swash plate 8 against the first biasing part 20; and a regulator 50 configured to control the control pressure guided to the first biasing part 20, wherein the regulator 50 has: a control spool 52 configured to adjust the control pressure by being moved in response to the biasing force exerted by an outer spring 51a and an inner spring 51b configured to be extended and compressed by following a tilting of the swash plate 8; an auxiliary spring 61 configured to exert the biasing force to the control spool 52 against the biasing force exerted by the outer spring 51a and the inner spring 51b; and the accommodating chamber 65 configured to accommodate the auxiliary spring 61, and the signal pressure is guided to the accommodating chamber 65, the signal pressure exerting the thrust force to the control spool 52.