NJZ type backstop is mainly composed of an outer ring (with a force arm), a backstop mechanism, an inner ring and other components. During rotation, the inner and outer rings are supported and positioned by bearings, ensuring flexible operation and uniform clearance，the backstop elements are evenly arranged inside, with individual built-in springs to guarantee reliable backstopping.

During normal operation, the inner ring drives the backstop mechanism to rotate at low speed inside the outer ring.Excellent lubrication helps form an oil wedge to reduce frictional resistance and prolong service life.

When the inner and outer rings tend to rotate in reverse, the backstop mechanism wedges the inner and outer rings tightly into one body, realizing a backlash-free backstop function. It locks the inner and outer rings, transmits the reverse torque from the inner ring to other fixed parts, and bears the torque load accordingly.