Development of a lightweight, compact, high-performance timing chain drive system

TSUBAKIMOTO CHAIN CO.

Outline

Timing drive system that was adopted by a car maker A, was optimized the product shape and material quality and achieved to reduce the weight. Also, it contributed to reduce the size and weight of oil pump by reducing engine oil amount that is used for the system significantly and it succeeded to reduce friction that occurs during driving by an engine.
For practical example, the system reduce a friction with intended shoe of slide by introducing tribology concept on the shape of slide area of timing chain.
Also, the better impact was obtained on shoe material quality that it would improve the chain slide. As a result, the system was contributed to a part of improvement of fuel cost and reduction of Co2 emission.

Description

Target:
Achieve 0.2%, exceeds 0.1% of fuel reduction with current spec and expand to introduce the system that was composed with same concept to other engine type in order to contribute to improvement of fuel cost on internal-combustion of conventional ENG, HEV and PHEV that some makers are developing.

Issue:
Determination of limit of reduction impact allowance by the shape, introduction of new material to balance the conflict of degraded strength according to reduction of weight and research & development to review the structure and function

Impact:
3.3km/L of fuel cost (calculated the average from the vehicle catalog) improved on 2.5L petrol engine compared with same ordinary capacity. Estimated contribution on reduction of CO2 emission is 1100t CO2/year in 2019 (result) and 8600t CO2/year in 2050 with the following condition:
Number of sales in sets: 1.39 million sets/year in 2019 (result) and 11 million sets in 2050 (estimation)
Average fuel cost of vehicle with objective engine: 25.2km/L
Yearly odometer: 8,700km. CO2 emission factor: 2.322kg-CO2/L
Set the reduction ratio as double to expand the current impact further and aim 16,000t CO2/year in 2050.