Requesting a Japanese translation, please ask someone who is an expert in mechanical engineering to answer. Urgent

The content and process of the problem

1) Broken O-ring fragments in the product were found in the vibrating screen.

From the size of the O-ring, it can be inferred that it is the O-ring used in the ball bearing shaft seal in our ball valve.

2) After disassembling and internally confirming the three ball valves shipped to Nippon Shouken, it was found that of the upper and lower O-rings used in the ball bearing shaft seals, the lower one was completely broken. . 2.? Reason

The ball valve should have gone through internal verification such as durability testing when it was developed. However, the problem still occurred, so the company conducted another inspection and found that the problem may have been caused by poor assembly of the O-ring during the assembly process of our company.

①Ball assembly in the casing

②カラー? , The seat ring is assembled starting from the three directions of the ball.

③Install 2 O-rings on the bottom of the roller.

④Insert the roller into the shaft hole of the top cover, and install the top cover from above the casing.

⑤ Before the top cover is installed at the regular position (lowermost part) of the upper part of the casing, the lower O-ring is pressed by the upper O-ring, and part of the O-ring is extruded into the O-ring groove. outside.

⑥The top cover is in the regular position on the upper part of the casing, and the O-ring is clamped under the top cover and on top of the balls, and then assembled.

⑦ Three-way Branch thus fixes the position of the ball.

⑧The rotation of the balls during flow path switching caused the O-ring to rupture.

The following things can be confirmed from the location and shape of the o-ring scratches. (Refer to the pictures and photos below)

From these pictures, we can find that the problem occurred due to the poor installation of the O-ring during the assembly process of our company.

The O-ring is pressed during installation, but it cannot be judged by feeling when the top cover is installed. After installation, the shaft seal is hidden in the casing. After the top cover is installed, it cannot be visually inspected. Check the condition of the o-ring.

The reason this time is due to poor installation of our company. Because the correct assembly was not performed, and no relevant confirmation work was performed after the assembly was completed.

For reference, record the operating procedures of the operators as follows:

Operator A inserts the O-ring into the top cover and then installs it into the roller.

Operator B inserts the O-ring into the roller and then into the top cover.

Operator C: The top cover and O-ring are inserted and assembled into the roller.

3. Solutions

1) Set a new O-ring groove on the top cover to form a ring that will not come off even if it is not installed in order. structure.

2) ?Insert a Teflon bushing into the first section of the O-ring so that the lower O-ring will not be extruded.

3) ?Assemble according to the operating sequence of inserting the O-ring into the top cover.

Our company’s recommended countermeasure plan 1) should be implemented in accordance with the following order of operations and used as a long-term countermeasure.

Installation sequence of countermeasure 1)

① Insert the lubricated O-ring into the top cover and install it.

② Insert the top cover into the roller that has been installed into the casing, and then install it into the casing.

③ Check whether the O-ring has fallen off from the gap between the ball shaft and the hole in the top cover.

④ Install the オイレ self-lubricating bearing.

The above is a hand-written translation of the information I consulted. Please point out any inaccuracies.