Attention to the Overhaul of the Pin Lug Coupling

Attention to the Overhaul of the Pin Lug Coupling

The elastic sleeve of the pin lug coupling The pin lug coupling uses a pin lug with an elastic sleeve (rubber material) on one end, which is installed in the flange holes of the two halves of the coupling to realize the connection of the two halves of the coupling.

The structure of the pin lug coupling is relatively simple, easy to manufacture, no lubrication, no need to be bonded with metal vulcanization, easy to replace the elastic sleeve of the pin lug coupling, no need to move the half coupling, and has certain compensation for the relative offset of the two axes and Shock absorbing performance.

The elastic sleeve is compressed and deformed during operation. Because the thickness of the elastic sleeve is thin, the volume is small, and the elastic deformation is limited, although the elastic sleeve pin lug coupling can compensate for the axial displacement and elasticity, the available compensation for the axial displacement is less, and the elasticity is relatively weak.

The elastic sleeve pin lug coupling relies on the locking force of the pin lug group to generate the friction torque on the contact surface, and compresses the rubber elastic sleeve to transmit the torque.

It is suitable for small and medium power shaft transmissions with good rigidity of the mounting base, high alignment, low impact load, and low requirements for vibration reduction.

Ⅰ. What are the precautions for overhauling the pin lug coupling?

1. When processing elastic ring spare parts, attention should be paid to the consistent material and correct size. There should be an interference of 0.2mm~0.4mm between the inner hole of the elastic ring and the pin lug. After the assembly and positioning are tightened, there should be a gap of 0.5mm~1.0mm between the outer circle of the elastic ring and the pin hole.

The elastic rings should be of the same size, and elastic rings of different sizes cannot be mixed, especially if the elastic rings on the same pin ear need to be replaced with new ones, if the old ones are used, the old ones should be used uniformly. The degree of wear and damage of the elastic ring does not exceed the standard, avoid mixing old and new.

For the elastic ring with too large size, if the gap between it and the pin hole does not meet the requirements after installation, if there is no spare parts or other unavoidable circumstances, the outer circle of the elastic ring can be trimmed with a fine file to make it meet pin lug coupling clearance requirements.

2. The positioning taper hole of the gear coupling plays the role of positioning the pin lug bolt, so the matching part of the taper hole should be carefully checked.

If the conical surface is found to be defective, worn or deformed, it should be dealt with or replaced. When processing pin lug bolts, it should be processed according to the original drawings of the manufacturer.

If there is no manufacturer's original drawing, special attention should be paid to the accuracy of the taper size of the taper hole when surveying and drawing parts. The taper does not match, which will lead to improper installation of pin lug bolts or skewed positioning, resulting in equipment operation defects.

3. The bolts of the pin lug coupling should be carefully inspected to check their straightness, surface finish, and surface roundness. Those with defects such as bending deformation and rough surface should be replaced.

The elastic pin lug coupling belongs to the high elastic coupling with rubber or polyurethane as the elastic element. It has the characteristics of light weight, convenient installation, large amount of displacement compensation in all directions, large damping, strong vibration absorption ability and frequency modulation ability, etc., and can better Protects main couplings, gearboxes and shafting.

Ⅱ. What are the general factors that lead to the damage of the pin lug coupling?

1. First of all, except for its own quality problems and torsional vibration, according to the principle of the high-elastic coupling, it is a rubber component that is torsionally loaded. The rubber component can be designed as a single row or multiple rows.

Each rubber component has a variety of standard rigidities to choose from, which can meet the rigidity requirements determined by torsional vibration calculations in a large range.

The main purpose of using highly elastic pin-lug couplings in ship power systems is to transmit power and torque, compensate for radial, axial and angular alignment errors, and compensate for oscillations in rotational momentum. Adjust the natural frequency of the system.

2. The damper of the elastic element sinks, causing the misalignment of the shaft system and generating additional torque, and the rubber of the elastic pin lug coupling is prone to thermal fracture accidents.

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