SDT Transmission worm gear reducer is a transmission mechanism with a compact structure, large transmission ratio, and self-locking function under certain conditions. among worm gear reducers, the hollow shaft type worm gear reducer not only has multifunction but is also easy to install, has reasonable structure, more and more widely used. It is one of the most commonly used gear reducers. on basis of decades of experience, we concluded other brands old worm gearbox common problems from our customers

Common problems worm gearbox:

1, Worm gear reducer overheating .

2, Noise from gearbox internal parts. 

3, Worm wheel over damaged.

4, Lubrication oil leakage.

 

1. Worm gear reducer overheating:

 
Reason  Solution
  • Worm gearbox Overloading
Adjust the working loading or change the bigger size gearbox.
  • Lack of lubrication oil 
Fill adequate lubrication oil
  • Inferior Lubrication Oil
Use Proper lubrication oil

 

 

 

 

 

 

 

⇑ Common Reason and solution

The worm gear reducer generally uses non-ferrous metal as the worm wheel in order to improve working efficiency, and the worm shaft uses harder steel. Because it is a sliding friction drive, it will generate higher heat during the operation, and function to worm wheel, worm shaft, and seals, etc. There is a difference in thermal expansion between gearbox parts so that a gap is generated in each mating surface,  There are four main reasons: First, whether the material is reasonable(gearbox quality question). Second, the surface quality of the friction surface. Third, the selection of lubricating oil, whether the amount of addition is correct, and the fourth is the assembly quality and the use environment.

 

2, Noise from gearbox internal parts. 

Reason  Solution
  • Poor gear mesh between the worm gear and shaft
Maintain/change worm gear or worm shaft
  • Worm wheel excessive wear
Replace worm wheel
  • Bearings damage or excessive bearing clearance 
Change to use new bearings
  • Insufficient lubrication oil
Add adequate lubrication oil
  • Foreign matter enter gear unit
Remove foreign matter or change lubrication oil

 

 

 

 

 

 

 

 

 

⇑ Common Reason and solution

unreasonable gear box slection also result in the worm gear(worm shaft)  continuously smashed to make the worm wheel wear.

unreasonable gearbox selection also results in the worm gear(worm shaft) being continuously smashed to make the worm wheel wear.


The worm gear is generally made of tin bronze. The paired worm material is generally hardened with 45 steel to HRC45-55. It is also commonly used 40Cr: hardened HRC50-55, ground to the roughness RaO.8fcm by the worm grinder, and the worm is in the normal operation of the gearbox. Just like a hardened «sickle», the worm gear(worm shaft) is continuously smashed to make the worm wheel wear. In general, this wear is very slow, like some gear reducers in our customers’ factory can be used for more than 10 years. If the wear progress is fast, it is necessary to consider whether the selection of the gear reducer is reasonable, whether there is overload operation, and the material of the worm gear, or the assembly quality, besides, customers also consider the industrial gear reducer working environment.

The bearing damage:

When the gear reducer fails, even if the gearbox is well sealed, we often find that the gear oil in the gear reducer has been emulsified, the bearing has been rusted, corroded, and damaged. because the gear oil is used during the stop of the gear reducer. The condensation of moisture generated after the heat is cooled; of course, is also closely related to the bearing quality and assembly process.

 

3. Worm wheel over damaged.

 
Reason  Solution
  • Worm gearbox Overloading
Adjust the working loading or change the bigger size gearbox.
  • Lack of lubrication oil 
Fill adequate lubrication oil
  • Inferior Lubrication Oil
Use Proper lubrication oil

 

 

 

 

 

 

 

⇑ Common Reason and solution

 

PC helical gear wide used on worm gear reducer.

PC helical gear wide used on worm gear reducer.

Drive small helical gear wear:
It usually occurs on a vertically mounted gear reducer, mainly related to the lubricant oil added amount and the selection of lubricant oil types. When the industrial gear reducer uses vertical installation, it is easy to cause insufficient oil quantity. When the speed reducer stops running, the transmission gear oil is lost between the motor and the industrial gear reducer, the gear can not get the proper lubrication oil protection, and it is not effective during startup or operation. Lubrication causes mechanical wear and even damage.

 

4, Lubrication oil leakage

the lubrication oil becomes thin due to the temperature increase, which easily resulted in oil leakage.

Reason  Solution
  • Oil seal damaged
Replace oil seal
  • Gasket damaged
Replace gasket
  • Excess oil capacity
Adjust oil capacity
  • Oil Plug loosed
Tighten oil plug
  • Oil immersion lens damaged
Replace oil immersion

 

 

 

 

 

 

 

 

 

⇑ Common Reason and solution

Worm gear reducer solution to other reasons:
(1) Guarantee the quality of assembly. In order to ensure the quality of the assembly, the factory purchased and made some special tools. When disassembling and installing the gear reducer worm gear, worm wheel, bearings, gears, and other components, try to avoid hitting directly with other tools such as hammer, SDT transmission suggests users try to use original parts and make the replacement when replacing gears and worm gears, please users pay attention to the tolerance when assembling the output shaft, D≤50mm, use H7/k6, D>50mm, use H7/m6, and use anti-adhesive or red dan oil to protect the hollow shaft, The shaft prevents wear and rust, prevents the scale of the fit, and it will be difficult to disassemble during maintenance.

(2) Selection of lubricating oil and additives. The worm gear reducer generally uses 220# gear oil. For some gears with a heavy load, frequent start and stop, with the tough working environment, SDT Transmission also selected some lubricant additives, when industrial gear reducer stopped, the gear oil remains attached to the gear surface, in order to form a protective film to prevent heavy loads, low speed, high torque, and metal-to-metal contact during start-up. The additive also contains a sealed regulator and a leak preventer to keep the seal soft and elastic, effectively reducing oil leakage.

(3) Selection of the installation position of the gear reducer. SDT Transmission does not suggest customers using vertical installation if gear reducer working condition is allowed. In the vertical installation, the gearbox’s added lubricating oil amount is much larger than that of the horizontal installation, which is likely to cause heat generation and oil leakage of the gear reducer. (in practical application, SDT Transmission has one customer who introduced 40,000 bottles/time pure draft beer production lines, some of which are installed vertically. after a period of operation, the transmission pinion has great wear and even damage. after SDT Transmission maintenance staff made the adjustment, the situation has been greatly improved.)

(4) Establish a corresponding lubrication maintenance system. SDT Transmission maintains the gear reducer according to the “five-set” principle of lubrication work so that each gear reducer has regular inspections by the incumbent. When our users find that the oil temperature rises significantly, the temperature rise exceeds 40 °C or the oil temperature drops above 80 °C, or more copper powder is found in the oil and abnormal noise is generated, stop using it immediately, find the industrial gearbox’s fault, and replace the lubricant oil before using it. When refueling, users pay attention to add the same lubrication oil amount and gearbox installation position, to ensure the gear reducer is properly lubricated.

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