Permanent magnet retarder
This is our eddy-current brake system using the magnetic force of a powerful neodium permanent magnet, the first in the world.

Outline

The Neotard Retarder is the world's first eddy-current brake system that generates braking force using the magnetic force of the world's strongest neodymium permanent magnet. This lightweight, compact system is installed as the auxiliary brake system on many heavy-duty trucks and buses. To comply with environmental regulations that are becoming stricter every year, automotive manufacturers are reducing running resistance and engine displacement for better fuel efficiency and emission control. However, these measures work against braking performance.
Did you know that the number of major accidents by commercial vehicles per year is about 3,700, and that trucks cause about 70% of these? Sixty percent of these truck accidents are collisions. It is always too late when one says, "If only the brakes had worked better."
Weighing only 40 kg, the permanent magnet-type retarder has drastically changed the image that retarders are heavy and bulky. It promises an even higher class of safety and comfort.
Characteristics
- The world's smallest and lightest, and easy to install
- Non-contact brakes make troublesome maintenance unnecessary
- Virtually no power consumption compared with electromagnetic retarders
- High praise from users
"Once you've tried it, you can't drive a truck without it." Every driver who has driven a truck with the permanent magnet-type retarder says the same thing. Do you think that retarders are expensive and troublesome? Do you think they are difficult to maintain?
The permanent magnet type is radically different -- a breakthrough over traditional retarders. So what's the secret?
No. 1 is safer operation.
- - You prevent accidents with powerful braking action -
The braking power of the Neotard Retarder is roughly equal to that of an engine brake and exhaust brake combined. In high-speed driving, deceleration time is reduced 40%. Braking distance is shortened by over 30%. In addition, the brake lining is kept cool, which allows for full braking response in an emergency, giving the driver a greater sense of security.
No. 2 is driver advantages.
- - Less fatigue thanks to easy handling -
You can count on the Neotard Retarder for braking on downhill grades of up to 5%. Simply set the lever once and drive as normal. It works strongly but also softly, which means no concern about your load shifting. The frequency of foot braking is cut by about 50%. This greatly contributes to less driver fatigue.
No. 3 Maintenance
- - Maintenance-free -
When you think of retarders, do you think of troublesome maintenance? It's true that traditional retarders had annoying problems like retarder coil burnout and oil leaks, and periodic oil changes were an extra job. However, the Neotard Retarder requires no maintenance at all. And, thanks to its simple construction, there is no need to worry about failure.
No. 4 is its business merit.
- - A quick return on your investment -
Once the retarder is installed, the frequency of applying the foot brake decreases and the brake lining temperature can be kept low. As a result, the brake lining wear also slows down dramatically. As much as 6-times longer lining life can be expected. Uneven tire wear is also reduced, meaning a longer life for your tires. In this way, your investment will be returned before you know it.
The data itself proves the safety and economy performance.
- *The above data was obtained from tests carried out on a 20-ton GVW truck. It should be considered only as an example, and none of the figures should be considered a guarantee.
Explore
Mechanism

- Structure
The construction of the permanent magnet type retarder is very simple. There are two main components: a rotor and a stator. The stator is attached at the rear of the transmission. It has a series of magnets with strong magnetic force on its interior. The rotor is a steel ring with many fins.
- Operation
The operation of the permanent magnet-type retarder is also simple. It is switched ON and OFF by compressed air supplied by the vehicle itself. This assures high reliability and superb response.

- Operating principle
The operating principle of the permanent magnet-type retarder is also simple. A series of magnets inside the stator is arranged so that any given magnetic pole faces the opposite magnetic pole of the adjacent magnet. When the retarder is switched OFF, no force is exerted on the rotor because the magnets are positioned straddling the pole pieces, and the magnetic circuit moves only through the pole pieces.
When the retarder is switched ON, a compressed-air cylinder rotates the magnet series by one-half magnet length, repositioning all the magnets directly beneath the pole pieces. When this happens, the magnetic circuit bridges the pole pieces and passes through the rotor, generating an eddy current on the inner surface of the rotor. This becomes the source of the braking force.

Controls
- The permanent magnet-type retarder is easy to operate.
-
- 1Pull the exhaust brake lever two steps toward you The retarder will operate when you take your foot off the accelerator pedal.
- 2Move the foot brake interlock switch to the Interlock side to turn it ON The retarder will operate when you step on the foot brake.
Installed models
The Neotard Retarder is installed in the trucks and buses listed below.
| type | CAR TYPE | Assignment | Engine type | |
|---|---|---|---|---|
| Turbocharged | Non-turbocharged | |||
| Semi tractor | Optional | Optional | ||
| Full tractor | Optional | Optional | ||
| Cargo (GVW20~25t) |
6×4 | Standard on GVW 25, 23t trucks. Others depending on the model. | Standard on GVW 25, 23t trucks. Others depending on the model. | |
| 6×2 | Standard on GVW 25, 23t trucks. Others depending on the model. | Standard on GVW 25, 23t trucks. Others depending on the model. | ||
| 8×4 low floor | Standard | Standard | ||
| 6×4 low floor | Standard | Standard | ||
| Dump truck | Optional | Optional | ||
- *Available on the 4-ton model (FORWARD).
| type | CAR TYPE | Assignment | Engine type | |
|---|---|---|---|---|
| P11C | K13C | |||
| Semi tractor | SH | − | Optional | |
| Full tractor | FN | − | Standard | |
| Cargo (GVW22~25t) |
FS | 6×4 | − | Selection option (Neotard Retarder or engine retarder) |
| FR | 6×2 | Selection option (Neotard Retarder or engine retarder) | Selection option (Neotard Retarder or engine retarder) | |
| FN | 6×2 front | Optional | Optional | |
| FW | 8×4 low floor | Selection option (Neotard Retarder or engine retarder) | Selection option (Neotard Retarder or engine retarder) | |
| FQ | 6×4 low floor | − | Selection option (Neotard Retarder or engine retarder) | |
| Cargo (GVW16~20t) |
FN | 6×2 front | − | Optional |
| FQ | 6×4 low floor | − | Optional | |
| FH | 4×2 | − | Optional | |
| type | CAR TYPE | Assignment | Engine type | |
|---|---|---|---|---|
| Turbocharged | Non-turbocharged | |||
| Cargo and dump (GVW20~25t) |
FV | 6×4 | − | J,M,P,S,T,U |
| FU | 6×2 | L,N,P | J,L,N,P,S,T | |
| FT | 6×2 front | L,N,R,T,V | L,N,R | |
| FS | 8×4 low floor | − | R,T | |
| FY | 6×4 low floor | J,T | J,N,R | |
| FP | 4×2 | − | F,H,J,L,N,T | |
- *Letters show the available wheelbase types
- *All optional
| Isuzu Motors | Hino Motors | Mitsubishi Motors |
|---|---|---|
| GALA Series | S'ELAGA R Series | AERO Series |
| Installed as standard on large vehicles for highways Installed as an option on sightseeing rental vehicles Installed as an option on mid-size vehicles |
Installed as standard on large vehicles for highways Installed as an option on sightseeing rental vehicles |
Installed as an option on large vehicles (Larger vehicles: EX sightseeing vehicles and larger) |
- *1The above lists are for information only and may differ depending on specifications.
- *2Ministry of Land, Infrastructure and Transportation regulations make installation of retarders mandatory on Class 2 Motorway Buses.
- *3Contact dealer for details.
For further product information
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