QJ218-N2-Ma Bearing: 90mm X 160mm X 30mm Four-Point Contact Ball Bearings

Four-point contact ball bearings QJ218-N2-MA

QJ218-N2-MA belongs to a four-point contact ball bearing. It has an inner diameter of 90mm, an outer diameter of 160mm, a thickness of 30mm, a single-row bearing with locating grooves, a solid brass cage and an outer ring guide.

Structural Features:

The inner and outer raceways of four-point contact ball bearings QJ218-N2-MA have a peach-shaped cross-section. When there is no load or only pure radial load, the steel ball and the collar present a four-point contact between them, which is also the origin of the name of the bearing.

The inner or outer ring of the bearing is made of two half-rings precisely fitted together, resulting in a very small radius of curvature of the grooves of the overall periphery or inner ring. This design allows the balls and the inner and outer rings to be in contact at all four "points", thus increasing the radial load capacity while at the same time being able to withstand large axial loads in both directions in a compact size.

The four-point contact ball bearings designed by QJ have a contact angle of 35° or 45°. The inner ring is a split inner ring, which allows a larger number of balls to be loaded into the bearing, thus increasing the load-carrying capacity of the bearing.

Performance Characteristics:

Four-point contact ball bearings QJ218-N2-MA can withstand radial loads and bi-directional axial loads and limit axial displacement in both directions. Compared with other ball bearings, when the radial clearance is the same, four-point contact ball bearings have smaller axial clearance and higher limiting speed.

The permissible rotational speed is high, and the operation is smooth. Its double half-ring can be removed from the complete set of bearings and mounted separately, which makes it particularly useful in applications (e.g. engines) that require high rotational speeds and are subjected to large radial and axial loads.

Under normal operating conditions, regardless of the axial load in any direction, a contact angle can be formed; the steel ball and the inner and outer raceways are each contacted at one point, which helps to avoid large sliding friction in the contact area.

Application Areas:

QJ218-N2-MA bearings, as four-point contact ball bearings, application scenario mainly focuses on the machinery and equipment that need to withstand bi-directional axial loads and high rotational speeds.

Precision machine tools: In high-speed, high-precision machine tool applications, QJ218-N2-MA bearings can provide stable rotation and precise positioning to ensure the machining accuracy and efficiency of the machine tool.

Aerospace equipment: The aerospace field has very high-performance requirements for bearings; QJ218-N2-MA bearings can withstand high rotational speeds, large loads, and axial loads in both directions and are suitable for aviation engines, spacecraft and other key components.

Textile Machinery: In textile machinery, such as spinning machines, looms, etc., QJ218-N2-MA bearings are used in high-speed rotating bearing parts, which can ensure the stable operation of the equipment and the quality of textiles.

Medical equipment: In medical equipment, such as CT machines, MRI machines and other high-end medical equipment, QJ218-N2-MA bearings are used in rotating parts, which can provide precise rotation and positioning to ensure the accuracy and reliability of medical equipment.

Precision instruments: In precision instruments, such as optical instruments, measuring instruments, etc., QJ218-N2-MA bearings are used in components that require high-precision rotation and positioning, which can ensure the measurement accuracy and stability of the instruments.

Heavy machinery: In heavy machinery, such as cranes, excavators, etc., QJ218-N2-MA bearings are used in bearing parts that are subject to large loads and impacts, which can ensure the stability and reliability of the equipment.