The noise generated by the pneumatic bucket (pneumatic hoist) reducer during operation is mainly due to gears, bearings, installation, lubrication, and external factors. The specific analysis is as follows:

1、 Gear problem

Gear wear or damage

Reason: Long term high load operation, insufficient lubrication, or manufacturing defects (such as tooth profile deviation, surface hardness not meeting standards) can lead to gear tooth surface wear, pitting, or cracking.

Case: Due to continuous operation every day, the gear tooth surface friction of a certain mining machinery reducer intensifies, and the wear exceeds the design allowable value, resulting in abnormal noise.

Solution: Regularly check the wear of the gears and use an endoscope to observe the inside of the enclosed gearbox; When the wear is severe, replace the matching gear with a new one and ensure the correct meshing direction.

Poor gear meshing

Reason: The parallelism and coaxiality of the shaft exceeded the tolerance during installation, or the meshing state changed due to external vibration impact during operation.

Case: Due to foundation settlement, the axis of a gearbox on a certain production line shifted, causing gear meshing to change from line contact to point contact, resulting in low-frequency noise.

Solution: Use tools such as a dial gauge to measure gear shaft parameters, adjust bearing preload to improve meshing status; Regularly review the alignment during operation.

Gear machining error

Reason: During tooth making, the rotation axis of the tooth blank does not coincide with the working axis (accumulated error in tooth pitch), or errors in rolling cutter manufacturing and grinding cause the tooth surface to have edges and root cutting.

Case: Due to the change in tooth profile after heat treatment, the impact of meshing in and out increases, resulting in an increase in noise level for a certain hard toothed gear.

Solution: Improve the precision of gear manufacturing and adopt modification technology to reduce dynamic load fluctuations; Small and medium-sized factories can reduce errors by optimizing their processing flow.

2、 Bearing issues

Bearing damage

Reason: High load and high-speed operation cause roller/raceway wear, or poor lubrication, water ingress, and foreign object contamination accelerate damage.

Case: The bearing of a certain machine tool reducer made periodic "clicking" sounds after the ball bearings were worn due to the aging of lubricating oil.

Solution: Regularly inspect the appearance and use a listening needle to monitor for abnormal friction sounds; Replace the bearings when damaged and install them strictly according to the instructions.

Excessive bearing clearance

Reason: Long term use may cause wear on the internal rollers/inner and outer rings, or thermal expansion in high-temperature environments may result in excessive clearance.

Case: The bearing clearance of a gearbox operating in a high-temperature environment increases, causing continuous buzzing sound.

Solution: Measure the clearance with a feeler gauge, and replace the bearing or adjust the preload when it exceeds the standard; For non separable bearings, matching parts can be replaced.

3、 Installation issues

Negative alignment

Reason: Inaccurate alignment during installation, or axis deviation caused by foundation settlement during operation.

Case: A large production line produces high-frequency abnormal noise due to uneven settlement of the foundation, which changes the alignment between the reducer and the motor.

Solution: Use a laser centering instrument or dial gauge to measure the centering situation, and regularly check during operation; Tighten the anchor bolts to ensure that the levelness/verticality meets the requirements.

Unstable installation position

Reason: The gearbox is placed unstably and shakes during operation, causing noise.

Case: A pneumatic hoist reducer made a "clanging" sound during operation due to loose installation foundation.

Solution: Choose high toughness and high damping base materials, optimize installation processes, and reinforce connectors.

4、 Lubrication issues

Insufficient or deteriorated lubricating oil

Reason: Oil seal aging, unreasonable design leading to oil leakage or evaporation, or using the wrong type of oil.

Case: A sand screening machine made a "rustling" sound when the lubricating oil dried up and the gear metal rubbed directly. After replacing the new oil, the abnormal noise disappeared.

Solution: Regularly check the oil level (once every 3 months) and purify the oil with an oil filter; Select specialized lubricating oil according to working conditions and avoid mixing.

Improper lubrication method

Reason: The lubrication method (such as splash lubrication, forced lubrication) does not match the working conditions, resulting in insufficient lubrication.

Case: A high-speed gearbox caused noise due to poor splash lubrication and insufficient bearing lubrication.

Solution: Adjust the lubrication method according to the working conditions, such as switching to a forced lubrication system.

5、 External factors

Abnormal load

Reason: Overloaded operation or excessive load fluctuations result in additional impact on gears/bearings.

Case: A crane gearbox operating under overload caused gear deformation and emitted a dull "buzzing" sound due to excessive load.

Solution: Choose the correct reducer model to ensure that the rated power/torque meets the requirements; Monitor the load during operation to avoid overloading/fluctuations.

Structural resonance

Reason: Resonance occurs between the gearbox body and the foundation support or connecting components.

Case: A certain pneumatic hoist reducer produces continuous buzzing due to resonance at a specific speed.

Solution: Conduct resonance testing during installation and increase the stiffness of the box by adding reinforcement bars; Adjust the operating speed to avoid resonance zone.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment