Custom Plastic Padded Fixed Armrests Manufacturers

What is the mechanical principle of the adjustment method (such as up and down lifting, forward and backward sliding, and rotation angle) of the plastic cushion fixed adjustable armrest? What are the materials and life test data of the core components (such as springs, dampers, and gears)?

Adjustment method and mechanical principle of plastic padded fixed adjustable armrest
Up and down lifting
Mechanical principle: Common up and down lifting adjustments use gas springs or spiral lifting mechanisms. The gas spring lifting system is filled with high-pressure gas. By controlling the degree of opening of the valve inside the gas spring, the amount of gas in and out is adjusted to achieve the rise or fall of the armrest. When the control button is pressed, the valve opens, the gas is slowly discharged, and the armrest descends under the action of gravity; release the button, the valve closes, the gas is sealed in the gas spring, and the plastic chair handrail remains at the corresponding height. The spiral lifting mechanism drives the nut connected to the armrest to move up and down through a motor or manually rotates the screw to achieve height adjustment. The threaded fit of the screw and the nut ensures the accuracy and stability of the adjustment and can withstand large loads.
Application scenarios: In office scenarios, office workers of different heights can adjust the height of the armrests according to their needs, so that the arms can maintain a natural and comfortable posture when typing and operating the mouse, effectively reducing shoulder and arm fatigue and improving work efficiency.
Forward and backward sliding
Mechanical principle: Forward and backward sliding adjustment usually relies on the cooperation of the slide rail and the slider. The slide rail is fixed on the frame of the chair, and the slider is connected to the armrest. The slider moves forward and backward on the slide rail by rolling the ball or roller. This structure can reduce friction resistance and make the plastic chair handrail slide more smoothly. In order to achieve precise positioning and prevent the armrest from sliding at will, a slot and a pin mechanism are also set on the slide rail. When the armrest slides to the appropriate position, the pin will be embedded in the slot to fix the armrest.
Application scenarios: When drawing, writing and other work, users can slide the plastic chair handrail forward to bring the arm closer to the work plane; when resting, slide the armrest backward to give the body more room for movement and increase comfort.
Rotation angle
Mechanical principle: The rotation angle adjustment generally adopts a combination of a rotating shaft and a damper. The rotating shaft serves as the central axis of the armrest's rotation and provides support for rotation. The damper controls the rotation speed and keeps the angle fixed. The damper is usually filled with a viscous liquid or a friction plate. When the armrest rotates, the viscosity of the liquid or the friction between the friction plates will generate a damping force, making the armrest rotate more smoothly and not over-rotating due to inertia. When the armrest rotates to the desired angle, the friction of the damper can firmly fix the armrest in that position.
Application scenario: When multiple people sit around and communicate, users can rotate the armrest to a certain angle to facilitate interaction with others; when getting up and leaving the chair, the rotating armrest can make more space for getting up and sitting down.
Material of core components
Spring
Material: Usually high-strength stainless steel springs or alloy springs are used. Stainless steel springs have good corrosion resistance and oxidation resistance, and are suitable for scenes with high environmental requirements, such as humid environments or places in contact with corrosive substances. Alloy springs improve the strength, elasticity and fatigue life of springs by adding different alloy elements (such as manganese, silicon, chromium, etc.), and can maintain good elastic properties under heavy loads. When selecting spring materials, Zhejiang Lubote Plastic Technology Co., Ltd. will strictly screen according to the use environment and load requirements of the handrail to ensure that the spring can work stably for a long time.
Damper
Material: The outer shell of the damper is generally made of high-strength engineering plastics, such as polycarbonate (PC) or nylon (PA). These plastics have good mechanical strength, wear resistance and chemical resistance, and can protect the internal structure of the damper. The internal damping medium, such as viscous liquid, mostly uses silicone oil, which has the characteristics of high viscosity, good stability, and low volatility, and can provide stable damping force; the friction plate is usually made of wear-resistant rubber or resin materials to ensure the friction performance under long-term use. During the production process, the material of the damper is strictly tested for quality to ensure that it meets the product performance requirements.
Gear
Material: Gears are generally made of metal materials, such as aluminum alloy or alloy steel. Aluminum alloy gears have the advantages of light weight, high strength and good heat dissipation performance, which can effectively reduce the overall weight of the handrail while meeting the transmission requirements. Alloy steel gears have higher hardness and wear resistance and are suitable for occasions where large torque is transmitted. In some products with high noise requirements, engineering plastic gears such as polyoxymethylene (POM) are also used, which have the characteristics of good self-lubrication and low noise. According to the transmission requirements and usage scenarios of the handrail, the gear material is reasonably selected, and the accuracy and meshing performance of the gear are guaranteed through precision machining technology.
Life test data of core components
Spring
Test method: Fatigue life test of the spring is carried out, and the spring is installed on the test equipment simulating actual use, and repeatedly compressed and stretched at the specified frequency and load. Record the number of cycles in which the spring has fatigue fracture or elasticity drops below the specified value.
Test data: After a large number of tests, high-strength stainless steel springs can be tested for more than 500,000 cycles without fracture or obvious elasticity drop under the rated load; the number of cycles of alloy springs can reach more than 800,000 times.
Damper
Test method: The damper is tested for durability by installing it on a test device that simulates the rotation or sliding of the handrail and repeatedly operating it at a specified speed and angle. During the test, the damping force change of the damper is regularly checked. When the damping force drops to 70% of the initial value, the damper is considered to be ineffective.
Test data: After testing, the damper using silicone oil as the damping medium can be rotated or slid about 300,000 times under normal use conditions; the damper using friction plates has a service life of about 200,000 times.
Gear
Test method: The gear is tested for wear life by installing the gear on the transmission test equipment and running it for a long time at a specified speed and torque. The gear tooth surface wear is regularly checked. When the tooth surface wear reaches the specified value, the gear is considered to be ineffective.
Test data: Under normal working conditions, aluminum alloy gears can run for about 1,000 hours without serious wear; alloy steel gears can run for more than 1,500 hours. The service life of engineering plastic gears is relatively short, about 500 hours.