Parallel Hydraulic Pumps With Servo Accumulators for On-Demand Oil Supply
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Solution Overview
Problem
Conventional hydraulic units face issues with high electric energy consumption, heat generation, noise production, leakage, and locking due to metal-to-metal contact, leading to inefficiencies and maintenance needs.
Innovation Solution
A compact hydraulic unit with parallel piston pumps driven by a low-power servomotor and ball screw mechanism, utilizing hydraulic pressure accumulators to manage oil flow and pressure, and employing self-lubricating sealing elements to reduce noise and leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional electric motors continuously drive hydraulic pumps, then hydraulic actuators can be moved, but electric energy is wasted when actuators are idle
Solution Approach 1:
The patent applies periodic action by using a servomotor that operates intermittently rather than continuously. The servomotor activates only when hydraulic actuators need movement, and stops when actuators are idle, eliminating continuous energy consumption. This is achieved through a control system that monitors actuator position and commands the servomotor accordingly, transforming the continuous operation mode into a periodic on-demand operation mode.
Solution Approach 2:
The patent implements dynamics by replacing the conventional constant-speed electric motor with a dynamically controllable servomotor. The servomotor's speed and activation state are dynamically adjusted based on real-time system demands, allowing the hydraulic pump to deliver oil only when needed. This dynamic control enables the system to adapt its energy consumption to actual operational requirements, avoiding waste during idle periods.
2Ease of operation
If oil is continuously pumped through valves back to reservoir, then hydraulic actuators can be controlled, but heat is generated due to friction
Solution Approach 1:
The patent reduces heat generation by eliminating continuous oil circulation through valves. Instead, the servomotor-driven pump delivers oil periodically only when actuators require movement. This intermittent operation dramatically reduces the frequency of valve actuation and oil recirculation, thereby minimizing friction-induced heat generation in the hydraulic system.
Solution Approach 2:
The patent extracts and eliminates the harmful continuous venting operation from the hydraulic system. By removing the constant oil recirculation through relief valves during idle periods, the system eliminates the primary source of frictional heat generation. The hydraulic oil is pumped only when necessary for actuator movement, taking out the wasteful continuous circulation that generates excessive heat.
3Productivity
If metal-to-metal contact occurs in pump moving parts, then pumps can function, but noise is generated
Solution Approach 1:
The patent replaces metal-to-metal contact in pump moving parts with alternative materials or mechanisms that reduce friction and noise. This may involve using non-metallic seal materials, polymer coatings, or precision-engineered surfaces that minimize direct metal contact. The substitution maintains the pumping function while dramatically reducing the noise generated by friction between moving components.
4Ease of operation
If clearance exists between piston axis and hole, then pistons can move, but hydraulic pressure is lost
Solution Approach 1:
The patent addresses pressure loss through clearance by modifying the parameters of the clearance itself - either reducing the clearance dimension through precision manufacturing or changing the properties of the materials involved. This may involve using wear-resistant coatings, precision-bored holes, or adjustable clearance mechanisms that maintain optimal gap dimensions throughout the pump's operational life, thereby minimizing pressure leakage while preserving piston mobility.
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 achieves significant electric energy savings (up to 90%), reduces noise, minimizes oil volume (up to 80%), and eliminates the need for auxiliary cooling, while maintaining system pressure and flexibility in pressure settings.
Implementation Method 1
a ball screw which, jointly, perform alternative rotational movements in the direction of movement of the plunger of a piston pump
Implementation Method 2
utilizing hydraulic pressure accumulators to manage oil flow and pressure
Implementation Method 3
employing self-lubricating sealing elements to reduce noise and leakage
Data Source
Figure 1
Figure 2
AI summary
The invention comprises a smart system that provides a machine or item of equipment with just the quantity of oil that will be used to perform one particular movement or more than one movement, thereby dispensing with supplying excess oil which ultimately is later returned to the tank in a venting system. The unit in question contains a ball screw (7), which is driven by a servomotor(6), and both have the function or raising and lowering two hydraulic sleeves (5E and 5D), of two hydraulic piston pumps (1 and 2), mounted in parallel and separately from one another, the function of which is to draw hydraulic oil from an oil reservoir(18) and to pump this pressurized oil into one, or more hydraulic pressure accumulators (14E and 14D), implementing this pumping continuously with alternating up- and-down movements, until the hydraulic pressure accumulator (14E and 14D) is completely full and, when it is full, a pressure sensor(25) will electronically control the halting of the servomotor(6), the latter being reactivated only when a hydraulic actuator of the machine or item of equipment that is using the present invention moves in order to perform a task, the servomotor(6) thus controlling the pumping and supply of oil to the system, but only in the form of the volume required to be replaced in the hydraulic pressure accumulator (14E and 14D), thereby giving rise to a large saving in terms of electric energy, using a low volume of oil, reducing noise and lowering the temperature of the oil.