How to design and select M-series hard tooth surface gearbox

Taking M2PSF70 gearbox as an example:

M: Series code (usually referring to a specific industrial gearbox series, such as the South High Gear M series or similar structures).

2: The number of transmission stages represents the second stage deceleration.

P: The structural form usually refers to parallel axis or planetary, but the probability of parallel axis helical gears is highest under the 70 engine base.

S: Installation method usually refers to shaft mounted or solid shaft input.

F: The input method usually refers to flange input (directly connected to the motor).

70: Machine base number, representing a center distance of 70mm (or a power level close to this specification).

The following are the selection and design verification steps for this specific model:

Step 1: Interpret specifications and scope of application

Machine base number 70 belongs to small and medium-sized gearboxes. In the hard tooth surface system, its volume is compact, but its load-bearing capacity is limited.

1. Applicable scenarios: Light conveyor lines, packaging machinery, small mixers, automation equipment.

2. Not applicable scenarios: heavy mining machinery, high impact loads (such as crushers).

3. Estimated power range: typically between 0.18kW and 3.0kW (depending on specific transmission ratio and speed).

Step 2: Core Selection Calculation (Three Elements)

Before deciding whether to choose M2PSF70, the following three key calculations must be completed:

1. Determine the transmission ratio (i)

The transmission ratio range for two-stage deceleration (2nd stage) is usually between 8 and 40.

Formula: i=Input/Output

2. Torque and operating condition coefficient verification (most critical)

Although hard toothed gears have high hardness (58-62HRC), their toughness is relatively poor and they are afraid of impact. Therefore, when selecting, it is necessary to introduce the operating condition coefficient

3. Thermal power verification

M2PSF70 has a small volume and limited heat dissipation area. If the equipment needs to operate continuously for 24 hours, the thermal power must be verified.

Principle: The actual input power must be less than the rated thermal power of the gearbox

If the actual input power is greater than the rated thermal power of the gearbox, even if the mechanical strength is sufficient, the oil temperature will still be too high, leading to oil leakage or tooth surface adhesion. At this point, it is necessary to install a cooling fan or cooling coil.

Step 3: Design and Installation Details

Regarding the flange input and shaft mounted structure of M2PSF70, attention should be paid to the following during design:

1. Motor matching (F-flange):

Confirm the motor flange standards (usually IEC standards such as 71B5, 80B5, etc.).

Solid shaft vs hollow shaft: Confirm whether the output end is a solid shaft or a hollow shaft. If it is a hollow shaft (common in the S series), a torsion arm should be designed to prevent the box from rotating with the shaft.

2. Lubrication method:

The 70 machine base usually uses splash lubrication (oil immersion lubrication).

Attention: If it is a vertical installation (with the output shaft facing downwards or upwards), the oil level height must be confirmed to prevent bearing oil shortage or oil seal leakage.