Riveting is a commonly used method of fastening and joining components. The riveting points of the stator and rotor core are an important part of the motor structure. The reasonable selection of the stator rotor lamination riveting scheme not only directly affects the performance and reliability of the motor, but is also related to the power output and service life of the motor.
What is Riveting Point?
Stator bonding lamination is also called bonded stator technology. The same goes for the rotor. Riveting is a bonding and mechanical fastening process where multiple layers of the rotor or stator laminations stack together and have a certain stacking thickness.
The Riveting Point typically refers to specific locations or points within the rotor and stator core laminations where rivets or other fastening methods secure laminations together.
Using progressive stamping manufacture stator and rotor riveting points common along the outer circumference or inner diameter.
The compound stamping fabricated stator and rotor laminations need drilled holes. This drilling is a riveting point that commonly uses rivets to stack laminations.
Types Of Stator And Rotor Core Riveting Points
Round Buckle Riveting Points
One of our common types is round buckle riveting points typically having a circular or rounded shape. They in position within the stator or rotor laminations provide a strong and stable connection.
It has the advantage that the depth of the buckle cannot be too deep, and it will not buckle up if it is too deep. The rounded shape helps distribute stress evenly, reducing the risk of deformation or eddy current to the laminations. Round buckle riveting points commonly apply in stepping motors.
Square Button Point Riveting Points
Square button point riveting points which is also called V-type rivet point. For round button points, the accuracy requirements of the punch are not so high. Its disadvantage is that it will be deep and cause certain damage to the insulation layer of the iron core stamping. If the requirements are not too high, use this type of square button point.
Circular Arc Riveting Points
Circular arc riveting points have a curved or semi-circular shape. Choosing this shape due to the distribution of stresses evenly along the arc curve. The torsion chute also has an iron core with high requirements for moving goods and iron core.
Circular arc riveting points are often used in applications where the laminations need to withstand dynamic forces, vibrations, or varying loads, as the arc design helps absorb and distribute these forces effectively.
The selection of the specific riveting point shape depends on the motor design, the intended application, and the mechanical requirements of the stator and rotor laminations.
Types Of Rivet For Joint Iron Core
Small motor cores usually use interlocked in the form of buckle points, however, for larger electrical iron cores we use rivets to connect the sheets together. Here are some common types of rivets for joining stator and rotor cores:
Round Head Rivets
It is a traditional rivet with a solid cylindrical shaft and a head on one end. They are well-suitable for applications where a high-strength, permanent connection. When joining thicker laminations in electric motor laminations commonly use solid rivets.
Flat head rivets
Flat-head rivets have wider heads and are usually used to join larger metal pieces.
Semi-Tubular Rivets
These have a tubular or semi-tubular shaft with a head on one end. These rivets are similar to solid rivets but have a partially hollow shaft. When need a secure but lighter-weight connection commonly use semi-tubular rivets.
Hollow Rivets
It has a hollow shaft and a head on one end. They are lightweight and suitable for applications where weight reduction is a consideration. When joining laminations made of thinner materials commonly use hollow rivets.
Blind Rivets (Pop Rivets)
Blind rivets, also known as pop rivets, are ideal for applications where access to only one side of the materials is possible. They have a hollow shaft and a mandrel (central pin). When installed, the mandrel is pulled through, expanding the rivet and forming a head on the blind side.
Pull rivets
Pull rivets, also called flow rivets, are rivets that can form a pull rivet head during the connection process. They are suitable where high-strength connections are required, such as in the aviation and aerospace sectors.
Large Flange Rivets
Large flange rivets have an extended flange or washer-like feature on the head. This extended flange provides additional support and load-bearing capacity, making it suitable for applications with high loads.
Conclusion
Motor core lamination riveting is an important step in lamination assembly. Reasonable selection and implementation of appropriate riveting solutions play a key role in the performance and reliability of the motor.
FAQS
Why are riveting points important in electric motor construction?
Riveting points are essential because they ensure that the laminations within the stator and rotor cores remain securely fastened. This prevents the laminations from shifting or vibrating during motor operation, contributing to motor efficiency and reducing noise.
What is the purpose of different rivet head shapes in motor stator and rotor cores?
Different rivet head shapes, such as round, flat, or countersunk, are chosen based on factors like load-bearing capacity and the desired surface finish. For example, countersunk rivet heads are used when a flush surface is needed.
Are there alternatives to riveting points for joining stator and rotor laminations?
Yes, alternatives include welding, adhesive bonding, and mechanical fasteners. The choice of method depends on factors like material compatibility and desired joint strength.
What are the advantages of riveting point bonding?
Reduced Thermal Distortion
Riveting does not involve heat application over large areas, unlike welding. This localized approach minimizes thermal distortion and warping of the metal sheets, preserving the dimensional accuracy and integrity of the laminations.
Mechanical Strength
Rivets provide strong mechanical bonds that are resistant to vibrations and stress, making riveting point bonding a durable choice for applications requiring robust construction, such as in automotive or industrial machinery.
Ease of Inspection and Maintenance
Riveted joints are generally easier to inspect for faults or wear compared to welded joints. Rivets can be drilled out and replaced without damaging the surrounding material, facilitating easier maintenance and repair.
No Additional Surface Finishing Required
Unlike welded joints, which may require grinding and finishing to smooth out the surface, riveted joints usually do not need additional surface treatment. This can save time and reduce manufacturing costs.