Piston Pump Retainer Bushing for Rotation Phase Stability
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Solution Overview
Problem
The existing liquid pressure rotary machines experience phase delays between the retainer and the cylinder block, leading to potential damage from piston contact with the cylinder block or retainer, which affects durability.
Innovation Solution
The design incorporates a retainer bushing with projecting portions and grooves that allow the retainer to be integrally rotatable and swingable, matching the rotation phase of the rotation shaft with the cylinder block, reducing phase delays and preventing abnormal piston tilt and contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the retainer is rotated together with the cylinder block, then the piston reciprocating motion is achieved, but a phase delay occurs between the retainer and the cylinder block causing piston contact with peripheral members
Solution Approach 1:
The retainer bushing acts as an intermediary component between the rotation shaft and the retainer. It includes projecting portions that engage with groove portions in the retainer, enabling the retainer to be integrally rotatable with the rotation shaft while maintaining precise rotation phase synchronization and preventing piston contact with peripheral members.
2Force
If the retainer and swash plate are connected by thrust bearing, then sliding resistance is suppressed, but the retainer rotation phase may become unstable
Solution Approach 1:
The retainer bushing serves as a mediator that provides both rotational support and phase synchronization. The projecting portions with curved leading end portions engage with groove portions to guide the retainer's rotational motion, ensuring stable rotation phase while the thrust bearing handles the sliding resistance between the retainer and swash plate.
Solution Approach 2:
The leading end portions of the projecting portions are formed with curved surfaces that fit into the groove portions. This curved geometry allows smooth engagement and disengagement while maintaining rotational synchronization, reducing冲击 and improving the stability of the retainer's rotation phase.
3Productivity
If the piston reciprocating motion is increased, then the pump capacity is improved, but the phase delay causes piston contact and damage
Solution Approach 1:
The retainer bushing with its projecting and groove portions ensures that the retainer rotates in precise synchronization with the cylinder block, eliminating phase delays. This allows the piston reciprocating motion to be maximized for improved pump capacity without causing contact between pistons and peripheral members, thereby maintaining durability.
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 configuration enhances the durability of the liquid pressure rotary machine by stabilizing the rotation phase, reducing sliding resistance, and minimizing oil leakage, thereby improving volumetric efficiency and reducing pulsation in oil pressure.
Implementation Method 1
By engaging ball pins of the retainer bushing with spherical surface pin grooves of the retainer, the retainer and the retainer bushing are integrally rotatable about the center axis of the rotation shaft
Implementation Method 2
the retainer is swung about the spherical surface center by moving the retainer bushing spherical surface portion and the retainer spherical surface portion into sliding contact with each other
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A liquid pressure rotary machine in which a rotation delay of a retainer with respect to a cylinder block is reduced and contact of pistons placed between the retainer and the cylinder block with peripheral members is suppressed is provided. A piston pump includes a rotation shaft, a cylinder block, piston heads, piston rods, a retainer, a swash plate, and a tilt adjustment mechanism. When the tilt adjustment mechanism swings the swash plate, a discharge amount of the piston pump becomes variable. The retainer to be rotated together with the piston heads and the piston rods is supported by a retainer bushing provided in the rotation shaft. By engaging ball pins of the retainer bushing with spherical surface pin grooves of the retainer, the retainer and the retainer bushing are integrally rotatable about the center axis of the rotation shaft and the retainer is swung about the spherical surface center.