reborn industrial empire

Chapter 494: Wheel Hub Motor Drive

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"In fact, the most important issue in the current field of electric vehicle research and development is how to solve the problem of in-wheel motors. I believe you are not clear about this, right?"

Jin Xiaoqiang asked Fang Shanhai. As a designer who has been engaged in automobile design for many years, Fang Shanhai certainly knew what this wheel hub motor was.\\.com first release\\

Although he has not been engaged in the research and development of new energy vehicles, he is still very clear about the concept of this new energy vehicle field.

And because he has been engaged in the research and development of concept trucks, he has long been familiar with this wheel-hub electric drive technology that has been applied to large trucks for a long time, and he has made considerable achievements in the research of this technology.

, very own opinions.

You must know that in the following years, the two large concept trucks he designed both used this wheel hub drive technology.

It's just that he had never thought about this before, so he didn't understand the all-wheel drive technology mentioned by Jin Xiaoqiang in the drawings. Now that Jin Xiaoqiang mentioned the wheel hub motor drive, he immediately understood what Jin Xiaoqiang wanted about this car.

The idea of ​​​​the car, and what he didn't understand before when he looked at the drawings, now it was all understood and understood.

The key to this technology is actually to integrate a drive motor into the wheel hub, and then directly transmit power to the motor through the vehicle battery or the engine to achieve the purpose of rotating the wheel hub, thereby allowing the wheel to rotate and allowing the vehicle to move

Driving on the road.

In this way, the mechanical devices originally required on the car will be omitted, thereby reducing the weight of the car body, simplifying the mechanical structure, and a series of other issues.

In fact, this wheel hub motor drive technology is not a new technology. As early as 1900, Porsche had manufactured an electric vehicle with a front wheel hub equipped with a drive motor. Later, in the 1970s, General Motors introduced this technology.

This kind of wheel hub was installed on large mining dump trucks, and later this technology was widely used on public transportation vehicles that frequently have passengers getting on and off in cities.

In the 1990s, a Japanese automobile manufacturer launched a large number of in-wheel motor-driven vehicles. For example, Mitsubishi once launched an in-wheel motor-driven Lancer evo, and Honda also launched the rcx, etc.

Car model.

Later, the Americans were not far behind. In 2002, General Motors also launched a series of concept models such as the independent Magic and Squel that were driven by in-wheel motors. (See the latest update of this book)

However, due to various reasons, these models were not able to be mass-produced on a large scale.

Now in the research and development of in-wheel motor drives, the Japanese are currently at the forefront of the world.

At present, this kind of wheel hub motor drive technology is not very backward when used in large commercial vehicles or trucks. GM even once specially developed an internal combustion engine for a 150-ton heavy transport truck.

It uses a hub-driven motor and has been working very well.

The driving methods of in-wheel motors are also divided into two methods: inner rotor and outer rotor. In the past, traditional driving methods generally used the outer rotor driving method.

The external rotor type uses a low-speed external rotor motor. The maximum speed of the motor is 1000-1500r/min. There is no reduction device, and the wheel speed is the same as the motor.

The inner-rotor type uses a high-speed inner-rotor motor and is equipped with a fixed transmission ratio reducer. In order to obtain higher power density, the motor speed can be as high as 10,000r/min.

Currently, with the emergence of more compact planetary gear reducers, inner-rotor hub motors are more competitive than low-speed outer-rotor types in terms of power density and are becoming more and more popular.

Models driven by in-wheel motors have many advantages over traditional internal combustion engine-driven models.

Generally speaking, for traditional vehicles, clutches, transmissions, drive shafts, differentials and even transfer cases are all essential parts of the vehicle. Not only are these components heavy in weight, but they also make the structure of the vehicle more complex. At the same time,

There are also issues with the need for regular maintenance and failure rates.

But the wheel hub motor solves this problem very well. It can make the above-mentioned clutch, transmission, drive shaft, differential and other parts disappear in the car, making the structure of the car body simpler.

In addition to having a simpler structure, vehicles driven by in-wheel motors can achieve better space utilization, and the transmission efficiency is also much higher.

The second advantage of using in-wheel motor drive is that the in-wheel motor enables the vehicle to have the characteristics of independent driving of a single wheel.

Therefore, whether it is front-wheel drive, rear-wheel drive or four-wheel drive, it can be realized relatively easily.

The full-time four-wheel drive system that has caused countless automotive engineers a headache in the past is very easy to implement on vehicles driven by in-wheel motors.

At the same time, the wheel hub motor can realize differential steering similar to a tracked vehicle through the different speeds of the left and right wheels or even reverse rotation, which can greatly reduce the turning radius of the vehicle. Under special circumstances, it can even achieve in-situ steering. Of course, this will

It causes greater wear and tear on the vehicle's steering mechanism and tires, but it is very valuable for special vehicles.

The third advantage of in-wheel motor drive is that it can be applied to various energy drive technologies, whether it is internal gas, pure electric vehicles, hybrid vehicles, or fuel cell vehicles. This technology can be used with various power drive technologies.

adaptation.

As far as the current new energy models are concerned, many of them use electric drive, so the wheel hub motor drive comes in handy.

Whether it is a pure electric vehicle, a fuel cell electric vehicle, or an extended-range electric vehicle, an in-wheel motor can be used as the main driving force.

Even for hybrid vehicles, the in-wheel motor can be used as a boost when starting or accelerating rapidly, which can be said to be a multi-purpose machine.

At the same time, many technologies of new energy vehicles, such as braking energy recovery, that is, regenerative braking, can also be easily implemented on in-wheel motor-driven models.

However, in-wheel motor drive technology is not without its shortcomings. The biggest challenge it currently faces is its two shortcomings.

Its first disadvantage is that the use of a hub motor device will greatly increase the unsprung mass of the car's suspension. Another problem is the moment of inertia of the hub motor. Both of these points will greatly affect the driver's perception of the car.

The controllability of the car.

For current ordinary civilian vehicles, the majority of manufacturers often use relatively lightweight materials such as aluminum alloys to make suspension components to reduce the unsprung mass and improve the response speed of the suspension.

However, the wheel hub motor increases the unsprung mass significantly and also increases the rotational inertia of the wheel hub, which is detrimental to the vehicle's handling performance.

But if such an in-wheel motor is used in an electric vehicle or a hybrid vehicle, considering that most of these new energy vehicles are limited to transportation rather than pursuing power performance, this is not a huge flaw.

.

For large trucks or buses, maneuverability is not considered. For such large transport vehicles, energy saving, slow speed, and safety are the key factors to consider.

The second shortcoming of in-wheel motor drive is the fatal flaw of this drive system. The reason why this current in-wheel motor drive technology has not been widely promoted is precisely because of this shortcoming.

This problem is about sealing and heat dissipation!

Obviously, this drive system is to integrate the motor into the wheel. In this way, when the car is driving on the road, it will often encounter some particularly complex road conditions.

For example, if the car has to wade through water or go on some bad roads, the sealing issues of the car's motor system will be strictly assessed.

Because if water or dust enters the motor, the driving function of the motor will be greatly affected.

Moreover, when the motor is working, it will also generate a lot of heat, and because of the special wheel location where the motor is located, it is difficult for you to equip these motors with a water-cooling device on the wheel hub. Moreover, if air cooling is used,

In cold weather, when vehicles are operating in summer or on hot days, the temperature on the road is often higher than the air, especially in stop-and-go congested urban traffic environments.

As a result, if the heat dissipation is not good, it will easily cause the motor to be burned out.

If you use the method of opening holes for the motor to dissipate heat, this will conflict with the requirements of the motor to be sealed, waterproof, and dustproof, so this has become the most fatal shortcoming of the hub motor.

Even Canada's TM4, the world's largest manufacturer of in-wheel motors, and the United States' Wavecrest are difficult to solve this problem.

Therefore, regular replacement of the motor or maintenance of the motor poses a big problem to the cost of using the car!

Moreover, models using such in-wheel motor drive technology will also face the problem of braking energy consumption, but this is all for hybrid vehicles or pure electric vehicles. If it is a model using an internal combustion engine, it will not

We will face this problem, so it is not a big problem.

The above-mentioned technical shortcomings of wheel hub electric drive may be a big problem for other companies, but for Huayang Power and Jin Xiaoqiang, they are not a big problem.

Especially this kind of sealing and heat dissipation problem. You must know that most of the hub motors used in the world currently adopt air-cooled structures. There are also many that use water-cooled or oil-cooled structures, but water-cooled and oil-cooled hubs are used.

The cost of the motor will also be relatively high.

Water cooling is because of the complex system, and oil cooling is because of the cooling oil that needs to be used. However, this problem is not a problem at all for Jin Xiaoqiang who has special cooling oil.

And since he can have special cooling oil, he believes that he can also make special sealing oil...

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