How to test the sealing performance of Hanyi ball spline

The sealing performance test of Hanyi ball spline is an important part to ensure that it can effectively prevent lubricant leakage and external pollutant invasion in practical applications. Here are some common testing methods:
1. Static sealing test
Pressure test: Install the ball spline in a sealed test container, and observe the change in gas pressure within a specified time by filling the container with a certain pressure of gas. If the pressure drops beyond the allowable range, it indicates leakage and poor sealing performance. For example, if the pressure is increased to 0.5 MPa and held for 10 minutes, and the pressure drop does not exceed 0.05 MPa, it can be considered that the sealing performance is good.
Water pressure test: Similar to air pressure test, but using water as the medium. Soak the ball spline in water or spray water on its surface, then apply a certain amount of water pressure to check for any water droplets seeping out. This method provides a more intuitive way to detect the presence of leakage channels at the seal, but after testing, the ball spline needs to be dried to prevent rusting.
2. Dynamic sealing test
Rotating bench test: Install the ball spline on the rotating bench, simulate the rotational motion in actual work, and apply a certain amount of simulated lubricant or dye on the spline shaft. After running for a certain period of time at different speeds and load conditions, observe whether there is lubricant leakage at the seal and whether external pollutants have entered the interior of the spline. For example, during the process of gradually increasing the speed from 1000rpm to 5000rpm and the load from 100N to 500N, check the sealing condition every hour of operation.
Reciprocating motion test: For ball splines with reciprocating linear motion, a reciprocating motion test bench can be used for testing. Apply lubricant to the spline shaft and sprinkle simulated dust or impurities around it to allow the ball spline to reciprocate at the specified stroke and frequency. After a certain number of reciprocating movements, check whether there is lubricant leakage and impurities entering the seal, as well as whether the seal is worn or damaged. For example, set the stroke to 100mm, the frequency to 10 times per minute, and perform a check after 10000 reciprocating motions.
3. Special environment simulation testing
High temperature test: Place the ball spline in a high temperature test chamber and maintain it in a set high temperature environment (such as 150 ℃, 200 ℃, etc.) for a certain period of time, then perform the above static or dynamic sealing test to evaluate the sealing performance of the seal at high temperatures. Because high temperatures may cause changes in the performance of sealing materials, affecting the sealing effect.
Low temperature testing: Simulate extremely cold environments (such as -40 ℃, -50 ℃, etc.) in a low temperature test chamber, let the ball spline stand or run for a period of time at low temperature, and check the sealing performance. Low temperature can cause the seal to become hard and brittle, which may result in cracks or inadequate sealing.
Chemical corrosion test: Expose the ball spline to an environment containing corrosive media such as acid, alkali, salt, etc., soak or spray it for a certain period of time, and then conduct a sealing performance test. This test can verify the overall chemical corrosion resistance and sealing performance of the seals and ball splines, ensuring effective sealing even in harsh chemical environments.
4. Non destructive testing technology
Ultrasonic testing: Utilizing the propagation characteristics of ultrasonic waves in different media, when ultrasonic waves encounter leakage channels or defects in sealed areas, they will reflect, refract, and scatter, causing changes in the received signal. By analyzing ultrasonic signals, small leaks and sealing defects can be detected without causing damage to the ball spline.
Helium mass spectrometer leak detection: For ball splines that require extremely high sealing performance, a helium mass spectrometer leak detector can be used for detection. Place the ball spline in a vacuum environment, fill it with helium gas, and then use a helium mass spectrometer leak detector to detect any helium gas leakage. Helium molecules are small, lightweight, and have strong penetrability, capable of detecting extremely small leakage channels with extremely high sensitivity.