One-way bearing

One-way bearing is also called unidirectional bearing, it is a kind of bearing that can rotate freely in one direction and is locked running in the other direction. The metal shell of a one-way bearing contains a lot of rollers, needles or balls, and the shape of its rolling seat (cavity) makes it only roll in one direction, and rotation in the other direction will generate a lot of resistance.

Powder metallurgy one-way bearings are made of molding technology and sintering process, and their products are a mixture of metal powder (or metal powder and non-metal powder). Based on the research on the characteristics and process characteristics of powder metal, the corresponding technology and process regulations are adopted to change the shape, performance and structure of the powder, so that it can be used as the material for manufacturing bearing products that meet different needs.

The solid one-way bearing uses GCr15 bearing steel and the hardness is HRC61-65 after heat treatment. The bearing is characterized by small in size and has high load-bearing capacity, enough space for storing grease, and a long relubrication interval.

Powder metallurgy one-way bearings and solid one-way bearings can completely "lock up" the drive shaft when it is driven, so as to avoid the problem of insufficient "locking up" performance of traditional drawn outer ring of one-way bearings.

Main applications: textile machinery; printing machinery; automotive industry; household appliances and cash detectors. The models of one-way bearings are:

One-way bearings: HF, HFL, FC, FCB, RCB, RC, F, IWC, EWC, DC, CSK, CKB (B200), ASNU, CKA, FWD, NF, etc.

One-way bearings are commonly known as overrunning clutches and one-way clutches.

 1. The structure of slope and roller type design

 The basic structure of the slope and roller type of one-way clutch is consisted of an outer ring with a cylindrical inner bore, an inner ring with a slope, and a set of rollers that bear the spring force and are always in close contact with the inner and outer rings. As long as one of the rollers rotates in the raceway in the direction of movement, it will have an impact on the other roller. This arrangement essentially ensures the instantaneity of the overrun speed and the immediate driving capability.

Usage:

The one-way bearing of this design can be suitable for overrunning, indexing and anti-reverse that used in various environments.

One-way bearing

When it is used as an overrunning one-way clutch:

The slope type and roller type of one-way clutches will be installed in this way, that is, the outer ring is used as the overrunning member. This is very important for high-speed overtaking. In the application of the inner ring overrunning, the centrifugal force acting on the roller will cause the overrunning speed to be limited.

When it is used as a non-reverse one-way clutch:

A slope roller type one-way clutch with the inner ring rotating is only suitable for relatively low speeds. If the required speed is higher than the recommended speed, it is recommended to use a wedge-type one-way clutch. 

When it is used as an indexing one-way clutch

The outer ring is often regarded as a swing element, and the inner ring as a driven element. Otherwise, the inertia of the roller and spring will cause errors, especially at high frequencies. Indexing, the use of diluted lubricating oil and strong springs can provide them high accuracy and quality for high-speed frequencies indexing 

2. Wedge design

 This wedge-type of one-way overrunning clutch is generally composed of an inner ring, an outer ring, a wedge set, a wedge cage, a powerful spring and a bearing. The wedges transfer force from one raceway to the other raceway by wedging between the inner and outer rings. The wedge has two diagonal diameters, (that is, the distance from one corner of the wedge to the other diagonal) one of them is larger than the other. The wedge action occurs when the inner and outer rings rotate relative to each other ，it force the wedge to have a larger vertical position on a larger cross section.

3. Self-locking angle

The wedge effect mainly depends on the wedging and self-locking angle of the wedges between the inner and outer rings. The basic concept of the wedge one-way clutch requires that the friction coefficient of the wedge is related to the instant torque generated by the inner ring in the driving direction. This friction value must be greater than the tangent value of the self-locking angle. If it is in unsafe condition, wedging will not happen.

The self-locking angle is determined by the structure of the wedge, and the points on the inner and outer rings are connected with the wedge respectively.

The wedge is designed with a very low initial self-locking angle to ensure an absolute bond at the beginning. As the torque increases, a radial force is generated on the wedge that deflects the wedge raceway, causing the wedge to roll to a new position. The wedge is often designed to have a self-locking angle that can be gradually increased, just as it moves from the overriding position to the maximum load bearing position. A relatively large self-locking angle can reduce the radial force generated by the wedge. Therefore, large torque are allowed as long as the elongation and the Brinell hardness limit are within the requirements,