Fitting a Bearing Without Damaging It

Most bearings that fail early were damaged during fitting, not in service. A bearing is a precision component: pressing it in the wrong way, hammering it, or letting dirt in will shorten its life from years to weeks. This guide covers how to fit a bearing without damaging it.

စောစီးစွာ ပျက်စီးသော bearing အများစုသည် တပ်ဆင်စဉ်က ပျက်စီးခဲ့ခြင်း ဖြစ်သည်။ မှန်ကန်သော နည်းလမ်းဖြင့် တပ်ဆင်ရန် လိုအပ်သည်။

1. Before you start — မစတင်မီ

1. Work clean. Dirt is the most common cause of early bearing failure. | သန့်ရှင်းစွာ လုပ်ဆောင်ပါ။
2. Leave the new bearing in its packaging until the moment you fit it.
3. Inspect the shaft and the housing bore. If either is scored, worn or oval, a new bearing will not fix the problem.
4. Check the new bearing matches the old one: designation, seals and clearance marking.

2. Pressing a bearing on — ဖိတပ်ခြင်း

1. Use a press and a fitting sleeve that contacts only the correct ring.
2. Keep the bearing square to the shaft. A bearing started crooked will jam and score the shaft.
3. Apply steady pressure. Do not hammer the bearing directly, and never strike it with a steel hammer.
4. Press until the ring seats fully against its shoulder.

3. Heating a bearing instead — အပူပေး တပ်ဆင်ခြင်း

For a tight interference fit, heating the bearing expands it so it slides on without force. Use an induction heater or a clean oil bath.

• Heat to roughly 80°C to 110°C above the shaft temperature.
• Never exceed 120°C. Above that the steel loses hardness and the bearing is scrap even though it looks perfect.
• Never use an open flame or a welding torch. The heat is uneven and uncontrolled.
• Do not heat a sealed or shielded bearing to high temperature — the seals and the packed grease will be damaged.

၁၂၀ ဒီဂရီစင်တီဂရိတ် ကျော်လွန်၍ အပူမပေးပါနှင့်။ မီးလျှံဖြင့် လုံးဝ အပူမပေးပါနှင့်။

4. Greasing — ဆီချောဆီ ထည့်ခြင်း

Fill the free space in the bearing about one third to one half with grease. Do not pack it completely full. Over-greasing is a common cause of overheating, because the excess grease is churned rather than lubricating.

Use the grease type the vehicle manufacturer specifies, and never mix two different greases.

Bearing အတွင်း နေရာလွတ်၏ သုံးပုံတစ်ပုံမှ ထက်ဝက်ခန့်သာ ဆီထည့်ပါ။ အပြည့်ထည့်ပါက အပူလွန်ကဲနိုင်သည်။

5. Tapered roller bearings — set the endfloat — Tapered Roller ချိန်ညှိခြင်း

A tapered roller bearing is adjustable, and it will fail quickly if it is left too loose or too tight. After fitting, set the endfloat or preload to the vehicle manufacturer's specification and torque the hub nut to the specified figure. Do not guess this by feel.

Tapered roller bearing ကို ထုတ်လုပ်သူ သတ်မှတ်ချက်အတိုင်း ချိန်ညှိပြီး torque တန်ဖိုးအတိုင်း တင်းရမည်။

6. Do not do these — မလုပ်ရန်

• Do not spin a dry bearing with compressed air. It can reach destructive speed and throw the rolling elements.
• Do not wash a sealed bearing in solvent. The solvent removes the packed grease and cannot be replaced.
• Do not reuse a bearing you have pressed out. Removal almost always damages it.
• Do not fit a new bearing into a worn housing and expect it to last.