The reason why the gearbox oil temperature is too high

- Aug 15, 2019-

1 Air Cooler May Be Faulty

1.The Air Cooler Itself Is Faulty

If The Wire Is Short-Circuited, Open Circuit, Or Burned Out, The Fan Will Not Operate.

2.Dust Affects The Air Cooler Heat Dissipation

a Large Amount Of Dust Covering On The Heat Sink May Affect The Heat Dissipation Of The Air Cooler, Resulting In Insufficient Cooling Of The Lubricating Oil.

3.The Wiring Of The Air Cooler Is Wrong

Wiring Errors Can Cause The Fan To Reverse, Causing The Wind To Reverse And Affect Heat Dissipation.

2.Lubrication System To The Oil Distributor, The Oil Pipe Of The Cooler Is Reversed

The Two Outlets Of The Filter Are Respectively Marked To The Gearbox Or To The Cooler, And Enter The Oil Distributor Directly When The Temperature Is Low, And Enter The Cooler When The Temperature Is High. If The Oil Pipe Is Reversed, The High Temperature Oil Will Not Be Cooled By The Cooler, And The Oil Temperature Will Inevitably Be Too High. The Oil Pipe Can Be Installed As Required.

3.Lubrication System Pressure Valve Or Temperature Control Valve Error

In The Case That The Filter And The Gearbox Tubing Are Connected Correctly, When The Oil Temperature Exceeds 55 °c, The Filter To The Oil Distributor Tube Still Has Oil Flow (Judgment Method: The Oil Pipe Can Be Touched, If The Temperature Is Consistent With The Temperature Of The Distributor Or The Vibration Of The Oil Flow Indicates That The Oil Flows Through The Oil Pipe, Indicating That There Is a Problem With The Temperature Control Valve Of The Filter. You Can Consult The Lubrication System Manufacturer Or The Technical Department To Replace The Temperature Control Valve. If It Is The Pressure Valve Problem Of Ind Norman, It Will Be More Difficult And Needs Several Parties To Solve It Together.

4.Overflow Valve Problem

As a Pressure Relief Component, The Relief Valve Should Only Function When The Oil Temperature Of The Gearbox Is Low And The Pressure Is High. At Present, It Is Found That The Oil Temperature High Relief Valve Is Still Flowing, So That The Amount Of Oil Cooled Will Be Reduced, And Some Of The Oil Is Directly Returned To The Gear Box Without Cooling, Resulting In Insufficient Overall Cooling And High Oil Temperature. When The Oil Temperature Is High, The Pressure Is Low And The Overflow Valve Is Opened Again, It Should Be Contacted With The Lubrication System Manufacturer As Soon As Possible.

High Speed Shaft Bearing Temperature Is Too High

1.Bearing Oil Intake Is Insufficient

Open The Rear Box Observation Cover To Check The Oil Output Of The Bearing. If The Oil Is Low, The Oil Input Of The Bearing Is Insufficient. There Are Four Main Reasons For This:

1) The Oil Inlet Hole Design Is Too Small, Resulting In Insufficient Oil Intake;

2) The Oil Inlet Hole Of The Tank And The Oil Inlet Groove Of The Oil Inlet Ring Are Misaligned;

3) The Oil Hole Is Blocked By Impurities, Resulting In a Decrease In Oil Quantity;

4) The Oil Inlet Hole Is Not Drilled.

Check Whether The Above Reasons Are Based On Actual Conditions And Handle Them Accordingly.

2.Bearing Radial Clearance Is Too Small

The Bearing Must Be Operated To Ensure a Certain Radial Clearance. When The Clearance Is Too Small, The Roller And The Raceway Will Be Vigorous, And a Large Amount Of Heat Will Cause The Temperature To Rise. This Situation Is Relatively Rare, And The Radial Clearance Of The Upper End Of The Bearing Can Be Detected With a Feeler Gauge.

3.Gear Injection Is Insufficient

Insufficient Gear Injection Or Misalignment Of The Oil Hole Will Result In a High Gear Temperature, Which In Turn Will Be Transmitted To The Bearing Closer To The Gear To Make The Bearing Temperature High.

4.Oil Temperature Is Too High

In The Case Of Insufficient Cooling, The Oil Temperature Is Too High, So That The High-Speed Bearing Temperature Cannot Be Effectively Removed, Resulting In Excessive Bearing Temperature.

5.Oil Temperature Is Too Low

If The Oil Temperature Is Too Low, The High-Speed Shaft Bearing Temperature Will Be Too High. The Viscosity Of The Lubricating Oil Will Be Very High At Low Temperatures. The Oil Passing Through The Oil Inlet Hole Will Become Very Small, And The Viscosity Of The Oil With High Viscosity Will Be Very Poor. The Ability Will Also Be Much Worse, Resulting In Higher And Higher Bearing Temperatures, Resulting In a Vicious Circle.

This Situation Is Mainly Reflected In The Winter And The Gearbox Of The Water-Cooled Lubrication System, Such As The High Temperature Of The Fl2000h Bearing Of The Huitengxile.

6.Bearing Damage

Damage To The Bearing Can Cause The Roller To Run Unevenly, Especially If The High Speed Shaft Bearing Has a High Rotational Speed.

7.Friction Or Packing Too Tight

Interference Friction Of Parts And Over-Tightening Of The Packing Will Generate a Large Amount Of Frictional Heat, Which Will Increase The Bearing Temperature.

Lubrication System Common Problems

1.Lubrication System Can Not Afford Oil

Gearboxes With Mechanical Pumps, Such As The Fl1500a, Often Have Low Gearbox Inlet Pressures. The Reason Is Often Because The Mechanical Pump Can Not Supply Oil, The Main Reasons Are:

1.The Old Mechanical Pump Pump Cannot Store Oil In The Body. Therefore, The Air Pressure Cannot Be Opened After The Operation, So That The Oil Path Cannot Be Started. Adding a Trap At The Inlet End Of The Mechanical Pump Can Solve This Problem;

2.The Oil Pump Shaft Is Broken:

The Breakage Of The Oil Pump Shaft Will Make The Gears In The Pump Body Unable To Rotate, And Naturally It Is Impossible To Supply Oil;

3.Damage To The Oil Pump Shaft Seal:

Damage To The Seal Ring Makes The Oil Pump Cavity No Longer Sealed, And The Oil Flows Directly From The Gap Of The Seal Ring Back To The Gearbox And Cannot Enter The Lubricating Oil Circuit.

2.Lubrication System With Low Or No Pressure

The Main Pressure Of The Lubrication System Is:

1.The Electric Pump Oil Pump Shaft Coupling Is Damaged Or The Oil Pump Shaft Is Broken, So That The Motor Can Not Drive The Oil Pump Gear To Rotate;

2.If The Motor Line Is Reversed, The Motor May Be Turned Incorrectly Or The Motor Itself May Not Be Activated.

3.The Gearbox Oil Is Too Small, Can Not Afford Oil;

4.The Mechanical Pump Does Not Supply Oil.

3.Differential Pressure Sensor Alarm

This Problem Is a Very Common Problem In Gearboxes Of Heavy-Duty Wind Power Companies. The Reason Is That The Lubricating Oil Impurities Are Too Much To Block The Filter Element. The Gear Box In The Early Stage Is Seriously Blocked Due To Insufficient Factory Cleaning And Oil Contamination Caused By Packing Wear.

4.Lubrication System Noise Is Too Large

1.The Oil Pressure In The Electric Pump Is Too Large And There Are Too Many Bubbles In The Oil.

It Is Particularly Serious On The Two Gearboxes Of Guodian Flr1500g And Power-On Fl1250.

Under The Influence Of High Pressure And Bubbles In The Oil, The Electric Pump Operates With a Lot Of Noise. Adjusting The Relief Valve Of The Lubrication System To Reduce The Pressure Of The Pump Under Special Circumstances Can Effectively Solve This Problem, But The Pressure Of The Relief Valve Must Be Adjusted With The Consent Of The Company's Leader.

2.The Electric Pump To The Gearbox Exhaust Pipe Is Blocked, Resulting In High Filter Pressure And Bubble Confusion;

3.The Ventilation Cap Of The Gear Box Is Blocked, And The Air Pressure In The Gear Box Is Too High;

4.The Filter Pressure Difference Is Too Large;

5.The Oil Level In The Gearbox Is Too Low, And The Suction Port Sucks In Air Bubbles.

Gear Tooth Surface Common Problems


(Surface Crack Expansion, Abrasive Grain, Spalling) When The Gear Is Working, At The Tooth Surface Meshing, Due To The Long-Term Effect Of Cyclic Alternating Stress, When The Stress Peak Exceeds The Contact Fatigue Limit Of The Material, After a Certain Number Of Stress Cycles, First In The Vicinity Of The Pitch Line The Surface Of The Gear Produces Subtle Fatigue Cracks. As The Crack Expands, It Will Cause The Small Piece Of Metal To Peel Off, Resulting In Tooth Surface Pitting. Pitting Is The Formation Of Fine Fatigue Cracks Due To Metal Fatigue On The Contact Surface, And Metal Spalling Caused By Crack Propagation.


Gluing: Local Heating + Heavy Load, Insufficient Lubrication, Oil Deterioration

3.Peeling Off

4.Crush Injury

High Speed Shaft Movement

1.Four-Point Angular Contact Bearing Damage

The Wear Of The Rollers And Raceways Of The Four-Point Angular Contact Bearing Increases The Gap Between The Roller And The Inner Raceway, Causing The High Speed Shaft To Collide.

2.Four-Point Angular Contact Bearing Outer Ring Rotation

The Outer Ring Of The Angular Contact Bearing Is Positioned By The Pin. When The Pin Is Too Short Or The Pin Is Broken, The Outer Ring Can Not Be Axially Fixed And Rotate, So That The Outer Ring Of The Bearing And The Adjusting Pad And The End Cover Are Relatively Sliding Friction. As a Result, The End Face Wear Increases The Axial Gap, And The High-Speed Shaft Is Strung.

3.High Speed Shaft Round Nut Loose

This Is The Reason Why The High Speed Axis Series Occurs Most. If The Round Nut Locking Screw Is Loose Or Broken, The Nut Can Not Be Locked, And It Will Loosen In The Direction Of The Motor Under The Axial Impact Of The Four-Point Angular Contact Bearing, So That The Inner Ring Gap Of The Two Halves Of The Bearing Becomes Larger And Larger. The Striking Of The Inner Ring Of The Bearing Often Leads To The Wear Of The Pinion Journal, So In This Case The High Speed Shaft Is Generally Scrapped And Replaced.

4.High Speed Shaft Round Nuts Are Not Installed In Place

When The High-Speed Shaft Is Assembled, The Round Nut Itself Is Not Installed In Place, And There Is a Large Gap Between The Round Nut And The Inner Ring Of The Bearing, So That The Round Nut Fails To Perform The Positioning Function.

5.High-Speed Shaft Assembly Axial Clearance Is Not Well Controlled

1.The Axial Clearance Of The Outer Ring Of The High Speed Shaft Bearing Is Too Large;

2.The Axial Clearance Of The Inner Ring Of The High-Speed Bearing Is Too Large; (Mainly Reflected In The Gearbox Of The 750, 850 Series Fixed Bearing With Elastic Retaining Ring)