Meeting the Needs of Diversifying Powertrains

Although the age of the combustion engine continues, we need new automotive manufacturing to meet the growing demand for electric vehicles.

For vehicles such as HEV, PHEV, and EV, whose presence are expected to rapidly grow in the global market, a mechanism to transmit motor power to the axle is required.

We at Tsubaki are developing new products to meet the needs of electric vehicles such as next-generation chains, clutches, and timing chain drive systems.

Developing new products and units to meet the needs of electric vehicles.

We offer a variety of products by mechanism to meet the needed of electric vehicles.

Enedrive Chain -- playing an essential role in acceleration/deceleration and power transmission in electrified units

Enedrive製品 picture

The Enedrive Chain series achieves higher rpm, higher torque transmission and a wider reduction ratio compared to gear power transmission, enabling a highly efficient, versatile system.

For critical power transmission systems in electric vehicles, we offer a solution that realizes high-performance and eco-friendliness for the future with the Tsubaki Enedrive Chain series.

Cam Clutches -- Tsubaki brand clutches backed by proven results

Cam Clutches for motorcycle starters
Cam Clutches for motorcycle starters picture

Tsubaki Cam Clutches, in which a number of cams are arranged between the inner and outer races, are one-way clutches that transmit torque between both races in one direction and freely rotate in the other.

They are widely used not only in general industries, but also in in-vehicle applications such as starters for motorcycles, automotive torque converters, etc. as highly accurate and reliable clutches.

We offer a Cam Clutch best suited to your application based on our proven track record and experiences.

BB Series Cam Clutch
BB Series Cam Clutch picture

The BB Series Cam Clutch is a series that integrates a cam clutch into a ball bearing. This series functions both as an one-way clutch and a bearing within its compact body, allowing you to use your space more effectively.

In addition, this series is capable of transmitting larger torque than shell roller clutches thanks to the arrangement of multiple cams between the inner and outer races.

Supports the torque transmission/shut-off mechanism -- thin Cam Clutch only 3mm thick

Sample of Tsubaki's thin Cam Clutch

Reducing the size and weight of parts allows for more flexible application design and contributes to energy savings.

Tsubaki broke the mold and revisited the fundamental workings of the clutch to realize this new design -- an ultra-thin Cam Clutch that's
only 3mm thick.

This clutch is 70% lighter than conventional models, and enables a surprisingly compact and lightweight design.

Thickness comparison with conventional specification

New specification
New specification
Conventional specification
Conventional specification

Removal of garter springs and cam cages allows for a thinner design.

Garter springs are there to engage cams with the inner and outer races by applying pressure on the cams, and raise the responsiveness of power transmission.

We have optimized cam shape to support engagement through centrifugal force generated when clutches rotate.
Cam cages position the cams and assure uniform engagement with the inner and outer races. Their optimal shape allows them to uniformly stand against each other, which enables a thinner design.

Conventional specification
Cam shape

Transmits/shuts off torque depending on the number of rotations -- centrifugal clutch with a new mechanism

遠心クラッチ製品 picture

In automobiles, various devices in the powertrain rotate to transmit power from the source to the wheels.

The centrifugal clutch transmits power only when needed, and reduces energy loss.

Pivot type
Pivot type
Spline type
Spline type

Engage at low rpm / instant torque transmission / rotational engage & release

Can instantly synchronize/desynchronize input and output shaft at target rpm due to the "strut" effect, the same as with a cam clutch.

The pivot type can transmit torque at ultra-low speed due to the self gravity offset mechanism between shoes, which was impossible with conventional centrifugal clutches in principle.
Tsubaki can propose two opposite types of centrifugal clutches; “Centrifugal release clutch” that desynchronizes over target rpm, and “Centrifugal engage clutch” that synchronizes over target rpm.

Conventional clutch
Conventional clutch
Newly-developed clutch
Newly-developed clutch

Shuts down reverse input from the output shaft --- Reverse-Input Cutoff Clutch

Reverse-Input Cutoff Clutch picture

This type of clutch transmits power from the input shaft and shuts down reverse input from the output shaft.

Traditionally, clutches with similar functions used rollers and struts, and a highly accurate strut shape was required. In addition, the surface pressure had to be high because rollers and struts contacted each other linearly.

Tsubaki's newly-developed clutch uses a simple design that applies the cam clutch strut effect to transmit power.

Motor shaft Stop Rotate
Output shaft Lock Drive

Simple transmission function using the principle of Cam Clutches

When torque is transmitted from the input shaft, this clutch releases its strut and the input shaft rotates (disengage). On the other hand, when torque is transmitted from the output shaft, the output shaft doesn't rotate as this clutch can't release its strut.
Optimal in applications to compactly realize a bidirectional drive/disengage. (ex. power seats)

When rotating the input shaft…
出力軸に出力
When rotating the output shaft…
ドラムに出力

Generate new value from Tsubaki technology --- power transmission units

We combine our Enedrive Chain with a highly efficient and versatile deceleration mechanism and a sprocket embedded with Tsubaki's unique thin on/off clutch to offer an optimized unit that regenerates energy during deceleration, travels on just a motor, and eliminates the need for a starter motor.

Power transmission units
  • Energy regeneration during deceleration
  • Traveling by motor alone
  • Elimination of the starter motor

We utilize Tsubaki's conventional technology to provide new additional value to our customers.

Create new value by combining the functions of chains/sprockets and two clutches.

Chains&Sprockets
Chains and Sprockets

Effectively synchronize parallel shafts at any reduction ratio.

Clutch
Effectively synchronize parallel shafts at any reduction ratio.

Synchronize/desynchronize input and output shafts on the same shaft.

We at Tsubaki have created a new system to meet the needs of diversifying powertrains in April 2018. Since then, we have been developing new products for electric vehicles, such as next-generation chains, one-way clutches, and so on to be used in non-combustion engine power transmission areas. We are setting our sights on new electrification business.

New system fig.

Contact a Tsubaki representative for more information.

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