Diaphragm Pump Pressure Control via Motor Speed
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Solution Overview
Problem
Existing pressure regulating apparatuses for electronic sphygmomanometers require a slow exhaust valve, increasing the number of parts and manufacturing costs.
Innovation Solution
A diaphragm pump design that regulates pressure without a slow exhaust valve, utilizing a diaphragm with a cup-shaped pump portion, a driving device, fluid inlet, discharge and exhaust passages, and a control device to manage the rotational speed of the motor for pressure control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a slow exhaust valve is used to regulate pressure in the exhaust system, then pressure regulation is achieved, but the number of parts and manufacturing cost increase
Solution Approach 1:
The patent removes the slow exhaust valve from the exhaust system entirely. Instead, pressure regulation is achieved by controlling the discharge valve's opening/closing timing and the pump's rotational speed, eliminating the need for a separate exhaust regulation component and reducing overall system complexity
Solution Approach 2:
The discharge valve is given a dual function: it not only controls fluid discharge but also indirectly regulates exhaust pressure through its timing control. The motor's rotational speed control also serves dual purposes of driving the pump and regulating pressure, reducing the need for dedicated pressure regulation components
2Reliability
If a slow exhaust valve is used to regulate pressure, then pressure control is possible, but manufacturing cost increases
Solution Approach 1:
By removing the slow exhaust valve from the system, the patent eliminates the manufacturing cost associated with this component. The pressure control function is transferred to the existing discharge valve and motor speed control system, which are already part of the pump's basic structure
Solution Approach 2:
The system uses its own operational parameters (discharge valve timing and motor rotational speed) to achieve pressure regulation, rather than requiring an additional dedicated pressure regulation component. This self-regulating approach reduces component count and manufacturing complexity
3Device complexity
If the exhaust passage is always open, then pressure regulation is simplified, but fluid may be lost through the exhaust
Solution Approach 1:
The exhaust passage remains structurally open and simple, but the actual exhaust flow is dynamically controlled by the discharge valve's timing. The valve's opening and closing creates dynamic control over when fluid is discharged versus when it is exhausted, allowing pressure regulation without complex exhaust passage mechanisms
Solution Approach 2:
The discharge valve operates periodically, opening during the discharge phase to allow fluid outflow and closing during the exhaust phase to prevent fluid loss. This periodic operation of the discharge valve provides indirect control over the always-open exhaust passage, balancing simplicity with fluid conservation
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
Reduces manufacturing costs by eliminating the need for a slow exhaust valve while effectively regulating pressure through motor speed control, suitable for use in electronic sphygmomanometers and other pressure-regulating applications.
Implementation Method 1
a driving device connected to a bottom of the pump portion and configured to convert a rotation into a reciprocating motion and increase/decrease a capacity of the pump chamber
Implementation Method 2
a suction valve configured to open/close the suction passage to make a fluid flow from the fluid inlet toward the pump chamber in a process in which the capacity of the pump chamber increases
Implementation Method 3
a discharge valve configured to open/close the discharge passage to make the fluid flow from the pump chamber toward the fluid discharge port in a process in which the capacity of the pump chamber decreases
Implementation Method 4
the control device is configured to control a rotational speed of the motor and regulate a pressure of the fluid discharged from the fluid discharge port
Data Source
Figure 1
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Figure 3~4
AI summary
A diaphragm pump includes a fluid inlet, a fluid discharge port, and a fluid exhaust port that are open to outside of the diaphragm pump. The diaphragm pump further includes a pump chamber formed by a diaphragm, a suction passage that makes the pump chamber communicate with the fluid inlet; a suction valve that opens/closes the suction passage; a discharge passage that makes the pump chamber communicate with the fluid discharge port; a discharge valve that opens/closes the discharge passage; and an exhaust passage that makes the discharge passage communicate with the fluid exhaust port.