World's First “Ultra-Compact One-Way Clutch” Announced

NTN has developed the world's first “ultra-compact one-way clutch”. The roller-type clutch has an external diameter of only 6 mm. This small diameter is ideally suited for use in the hinges of the PC display screens of notebook PCs as they become smaller, thinner, and lighter (hinge section: Figure 1). Sales for PCs and other small mobile products are expected to expand in the future.

1.Background to Development

Currently, the hinge section of notebook PCs use torque limiters to securely position the screen when it is opened. Combining a one-way clutch in the hinge allows the outer ring to rotate freely in one direction. This type of torque limiter has been studied with the thought of improving performance so that the screen can be opened with just one hand. However, the existing one-way clutches must be mounted onto the shaft and the thin hinge section limits the size reduction that is possible.

2. Summary of the new product

The “ultra-compact one-way clutch”, newly developed by NTN (Figure 3), uses a completely new structure that incorporates the one-way clutch function into the shaft. NTN has succeeded in reducing down the one-way clutch to the same thickness as the shaft itself. The external diameter is half that of conventional one-way clutches that must be mounted onto the shaft. This new development makes it possible to reduce the thickness of the hinge section.

3. Features of the new product

1) Ultra-compact:

World's first one-way clutch with an external diameter of only 6 mm. The external diameter is only half that of previous one-way clutches (NTN comparison).

2) High lock function reliability

The roller clutch structure, utilizing a mechanical wedge effect results in a lock function that is highly reliable.

3) Easy assembly

A projection can be formed on the external diameter of the ultra-compact one-way clutch for reliable assembly with no chance of slip in use.

4) Shaft and clutch functions combined in one piece

4. Application: Small mobile products equipped with fold-over type display screens

5. On Sale: Planned for May 2002

6. Number of patents: 2

7.To inquire: Industrial Sales Planning and Marketing Department

Note 1: One-way clutch
A product that transmits rotational force to the inner ring when the outer ring turns in one direction but does not transmit rotational force when the outer ring turns in the reverse direction.
Note 2: Torque limiter
A product that controls the maximum torque that can be transmitted.

Figure 1: The hinge section of notebook PCs

Figure 2: Usual one-way clutch

Figure 3: Ultra-compact one-way clutch