How to choose the appropriate shim to fix the BWED120-121-1.1KW cycloidal pinwheel reducer

BWED120 is a two-stage horizontal cycloidal pinwheel reducer, and there is a certain degree of vibration impact during the operation of the 1.1KW power model. The selection of shims should focus on three core principles: matching the bearing capacity, meeting the fitting accuracy standard, and adapting to the working conditions with stability. The specific requirements are as follows:

1. Clarify the core selection parameters

One is the load-bearing capacity. The overall weight of this model of reducer is about 80-120kg (including the motor). Considering a vibration impact coefficient of 1.5-2.0, the load that a single shim should bear should not be less than 50-80kg. The other is the size adaptation, where the length of the shim should be 10-20mm longer than the width of the reducer base's ground plate, and the width should not be less than 2/3 of the ground plate width to avoid the shim being subjected to force displacement when bolts are tightened; The third is the accuracy level. Priority should be given to using grade 0 or grade 1 precision shims, with a working surface flatness error of ≤ 0.02mm/m, to ensure complete fit with the bottom surface of the machine base and installation foundation without gaps.

2. Select the type of shim according to the working conditions

For indoor working conditions with high basic flatness and no need for shock absorption, a flat pad iron made of cast iron HT200 material is selected, with a thickness controlled between 10-20mm, and the surface needs to be ground; For working conditions where the foundation flatness is poor and requires on-site fine adjustment of the level, inclined pad iron with a slope of 1:20 or 1:50 must be selected and used in pairs with flat pad iron, with an adjustment range controlled within 0-5mm. For working conditions where there is a need for shock absorption and noise reduction, and peripheral equipment is sensitive to vibration, rubber cast iron composite shock absorption pad iron should be selected, with a rubber hardness of 50-60 Shore and a single block bearing capacity of not less than 100kg, to avoid rubber aging causing the machine base to tilt; For working conditions with frequent adjustment of levels or high risk of foundation settlement, cast steel adjustable shims with threaded lifting structures are selected to improve the long-term load-bearing stability.

3. Determine the material standard for the pad iron

Prioritize the use of cast iron HT200/HT250 pad iron, which has high cost-effectiveness and good wear resistance, and is suitable for most industrial working conditions; In humid and corrosive environments, stainless steel 304 material pads should be selected, or cast iron pads should be hot-dip galvanized for rust prevention to prevent rusting and deformation; It is strictly prohibited to use steel plate cutting parts instead of standard shims. The steel plate has insufficient hardness and is prone to plastic deformation under long-term stress, which can lead to horizontal displacement of the machine base.

4. Follow the principles of quantity and layout

The number of shims should be consistent with the number of anchor bolts. BWED120 reducers are generally equipped with 4 anchor bolts, corresponding to 4 sets of shims; The maximum number of layers for each set of shims should not exceed 2. Stacking multiple layers can reduce stability and increase gaps due to vibration; The shim should be centrally arranged below each anchor bolt to ensure that the tightening force of the bolt is evenly transmitted to the installation foundation.

5. Key points for verification after selection

After the installation of the pad iron, use a 0.05mm feeler gauge to check the fitting surface, and the insertion depth should not exceed 1/3 of the pad iron width; After tightening the anchor bolts, manually rotate the output shaft of the gearbox without any jamming or abnormal noise; After a 15-20 minute no-load trial run and shutdown, check that there is no displacement of the shim and no deviation in the levelness of the machine base, which indicates that the selection is qualified.