# Mechanical power transmission: Technology advances

Toothed belts, smarter gears and plugging compressed-air leaks

Source page: https://www.materialinsights.org/energy/e_mechanical_transmission/advances/

What this tab covers The newest technologies in service or close to adoption, what each improves, and how the main options compare.

Mechanical transmission is mature; the advances are incremental efficiency gains (toothed belts, better gears, recovering exhaust air and smarter hydraulics) and new ropeway designs for city transport.

#### Latest advances
**Synchronous (toothed) belts** in service · 2012

Belts with teeth that engage pulley grooves instead of relying on friction.^[1](https://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/replace_vbelts_motor_systemts5.pdf)

*Improves:* About 98% efficiency with no slip; a 100 hp fan saves about 16,130 kWh a year against a 95% V-belt.
**Optimised helical gear geometry** research · 2021

Choosing gear ratio, tooth count and helix angle to cut friction.^[6](https://www.mdpi.com/2075-1702/9/11/264)

*Improves:* Modelled drive efficiency ranged from about 93.9% to 97.5% depending on design.
**Higher-efficiency fluid power** research · 2012

Best-practice and research programmes for pumps, valves and controls.^[2](https://info.ornl.gov/sites/publications/files/pub28014.pdf)

*Improves:* Could raise average US fluid power efficiency from 22% to 27% near term and 37% long term.
**Pneumatic exhaust recovery** research · 2012

Reusing the energy in exhausted compressed air.^[2](https://info.ornl.gov/sites/publications/files/pub28014.pdf)

*Improves:* Raised pneumatic efficiency by 14 to 23% in a cited study.
**Compressed-air leak programmes** in service · 2026

Updated Compressed Air Challenge guidance on finding and fixing leaks.^[3](https://www.compressedairchallenge.org/data/sites/1/media/library/factsheets2026/fact-sheet-7-compressed-air-system-leaks_updated2026.pdf)

*Improves:* Brings leakage from about 20% towards under 10% of output.
**New ropeway systems** in service · 2025-2026

Doppelmayr's 2025/26 projects included an urban ropeway in Paris, and its revenue rose 9.1% to about EUR 1.3 billion; HTI Group (Leitner, Poma) grew turnover 15.8% in 2025.^[9](https://www.news.at/ausflugsziele/doppelmayr-umsatz-wuchs-202526-auf-13-mrd-euro)^[16](https://www.leitwind.com/en/hti-group-a-year-of-results-and-investments/)

*Improves:* Extends rope transport into cities.

#### Comparing the options

| Option | Efficiency | Cost | Capacity or distance | Maturity |
|---|---|---|---|---|
| **Shafts and gears**^[6](https://www.mdpi.com/2075-1702/9/11/264) | 98 to 99% per mesh at best | Not quantified here | Metres; up to megawatts | mature |
| **Belts**^[1](https://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/replace_vbelts_motor_systemts5.pdf) | About 95% (V-belt) to 98% (synchronous) | Minimal premium for synchronous belts in new installations | Metres; small to medium power | mature |
| **Ropeways (ropes and cables)**^[7](https://blogs.worldbank.org/en/transport/innovation-air-using-cable-cars-urban-transport) | Not quantified here | US$10 million to 25 million per km (Latin American urban systems) | Average urban line 2.7 km; 1,000 to 2,000 passengers per hour each way | mature |
| **Hydraulic network**^[2](https://info.ornl.gov/sites/publications/files/pub28014.pdf)^[4](https://collection.sciencemuseumgroup.org.uk/people/ap28550/london-hydraulic-power-company) | About 21% (mobile) to 50% (industrial) end to end | Not quantified here | Factory scale today; city scale historically (about 180 miles of mains in London) | mature |
| **Compressed-air network**^[2](https://info.ornl.gov/sites/publications/files/pub28014.pdf)^[5](https://www.paris.fr/evenements/victor-popp-et-l-horlogerie-pneumatique-a-paris-98573) | 12 to 17% end to end | Useful energy about 6 to 8 times the price of the electricity used (calculated) | Factory scale today; about 1,000 km in historic Paris | mature |

Over short distances, shafts, gears and belts are hard to beat, and they sit inside almost every motor-driven machine. Over longer distances, electricity wins easily because wires lose only a few percent while fluid systems lose most of their energy. Hydraulics remain where huge forces are needed in a small space (excavators, presses), pneumatics where cheap, safe, simple tools matter more than efficiency, and ropeways where steep terrain or crowded streets make roads or rail hard to build.

#### Sources

1. [Replace V-belts with notched or synchronous belt drives (Motor Systems Tip Sheet #5)](https://www1.eere.energy.gov/manufacturing/tech_assistance/pdfs/replace_vbelts_motor_systemts5.pdf) US Department of Energy, Advanced Manufacturing Office, 2012
2. [Estimating the Impact (Energy, Emissions and Economics) of the U.S. Fluid Power Industry (ORNL/TM-2011/14), Love, Lanke and Alles](https://info.ornl.gov/sites/publications/files/pub28014.pdf) Oak Ridge National Laboratory, 2012
3. [Compressed Air System Leaks (Improving Compressed Air System Performance, Fact Sheet #7, Rev. 1)](https://www.compressedairchallenge.org/data/sites/1/media/library/factsheets2026/fact-sheet-7-compressed-air-system-leaks_updated2026.pdf) Compressed Air Challenge, 2026
4. [London Hydraulic Power Company](https://collection.sciencemuseumgroup.org.uk/people/ap28550/london-hydraulic-power-company) Science Museum Group Collection, 2025
5. [Victor Popp et l'horlogerie pneumatique à Paris](https://www.paris.fr/evenements/victor-popp-et-l-horlogerie-pneumatique-a-paris-98573) Ville de Paris, 2024
6. [Using the Box-Behnken response surface method to study parametric influence to improve the efficiency of helical gears (Machines 9(11), 264)](https://www.mdpi.com/2075-1702/9/11/264) MDPI, 2021
7. [Innovation in the air: using cable cars for urban transport](https://blogs.worldbank.org/en/transport/innovation-air-using-cable-cars-urban-transport) World Bank (Transport blog), 2017
8. [Doppelmayr: Umsatz wuchs 2025/26 auf 1,3 Mrd. Euro](https://www.news.at/ausflugsziele/doppelmayr-umsatz-wuchs-202526-auf-13-mrd-euro) APA (Austria Presse Agentur) via news.at, 2026
9. [HTI Group: a year of results and investments](https://www.leitwind.com/en/hti-group-a-year-of-results-and-investments/) Leitwind (HTI Group), 2026

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_mechanical_transmission/index.md)
- [Overview](https://www.materialinsights.org/energy/e_mechanical_transmission/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_mechanical_transmission/correlation/index.md)
- [How it works](https://www.materialinsights.org/energy/e_mechanical_transmission/explain/index.md)
- [Efficiency and losses](https://www.materialinsights.org/energy/e_mechanical_transmission/efficiency/index.md)
- [Value chain](https://www.materialinsights.org/energy/e_mechanical_transmission/valuechain/index.md)
- [Geopolitics and regulation](https://www.materialinsights.org/energy/e_mechanical_transmission/geopolitics/index.md)
- [Unit economics](https://www.materialinsights.org/energy/e_mechanical_transmission/economics/index.md)
- [Impact on the biosphere](https://www.materialinsights.org/energy/e_mechanical_transmission/biosphere/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_mechanical_transmission/links/index.md)