RU197978U1 - Bicycle generator - Google Patents

Abstract

This utility model relates to devices for generating electric current, namely, generators (cycle generators, dynamos) used in vehicles with pedal drive to generate current used in lighting systems. The essence of the utility model lies in the fact that the generator for a bicycle, containing a stator with coils, a rotor with permanent magnets, and also a drive disk connected to the rotor and rotated by contact with the wheel rim, has the following design: inside the case of the end-face generator, consisting of the cup and the hermetically sealed screw cap, the stator and rotor are mounted, the stator being located on the side of the cap and the rotor at the bottom of the cup, while rotation from the drive disk located outside the housing is transmitted to the rotor through a magnetic coupling, in which the rotor is a driven coupling half, the bottom glass - a protective screen between the driven and the leading coupling half, and the leading coupling coupling, rotated by the drive disk, is located outside the casing in a hermetically closed cavity formed by the bottom of the glass and another screw cover. The generator housing may be made of conductive non-magnetic material (metal or alloy), for example, aluminum, or non-metallic material. The technical result consists in reducing the frictional force in moving parts, and, as a result, increasing the efficiency of the device and the service life. 2 s.p. f-ly, 3 ill.

Description

This utility model relates to devices for generating electric current, namely, to generators (cycle generators, dynamo machines) used in vehicles with pedal drive to generate current used in lighting systems.

Electric generator - a device designed to convert mechanical energy into electrical energy. An electric generator is installed on a bicycle to receive electricity, which powers the lighting fixtures of the bicycle, and also, recently, to recharge the batteries of mobile phones, tablet computers, GPS navigators and other devices that the cyclist has with him [https://velomasterclass.ru / generator-elektrichestva-dlya-velosipeda].

A bicycle dynamo is often a generator of not direct but alternating current (the simplest design in the form of a fixed coil and a rotating permanent magnet, without a brush-collector assembly), since there is no need for direct current for a bicycle headlight [https: //ru.wikipedia. org / wiki / Dynamo machine].

Thus, the cycle generator consists of a coil with a wire rotating in a magnetic field created by the stator, or vice versa: the magnet rotates, and the coil is stationary. An electric current is generated when the lines of force of a moving magnet cross the coils of a wire coil. According to the Faraday law, the rotation energy is converted into alternating current, which is suitable for lighting devices, but not suitable for other devices powered by direct current, so the alternating current is rectified using a diode bridge and stabilized, limiting the maximum voltage value.

The main disadvantage of such a device for generating electricity is that the generator ceases to give out energy when the bicycle stops completely, and there is also a dependence of the voltage level on the speed of the bicycle, which creates certain inconveniences.

Modern batteries displace generators due to their small size and ability to deliver more power. Its value for the generator is 3-6 watts, while small batteries produce up to 15 watts or more. At the same time, if there is no way to charge the batteries, the generator will help out.

By design, generators for bicycles are divided into several types, two of them are used most often [https://electrosam.ru/glavnaja/jelektrooborudovanie/jelektropitanie/dinamo-mashina].

A hub internal generator or hub dynamo is integrated into the front or rear hub of the wheel. The power of this design can reach 3 watts at a voltage of 6 volts. The technologies for manufacturing sleeve generators are constantly being improved, the dimensions of the structure are becoming smaller and power is higher.

Dynamo hubs do not generate noise during operation, but their mass is greater than other models. Friction parts in the sleeve version of the device are absent. The generator operates due to a magnet having many poles, and made in the form of a ring. It is located in the sleeve housing and rotates around a fixed armature with a coil fixed on an axis. The rotation resistance of this design is very slight.

The cost of the sleeve generator is quite high. Installation is much more complicated compared to the bottle version. The disadvantages of the device also include the fact that it is impossible to disable the operation of the sleeve generator.

A more popular model of dynamo for a bicycle is a bottle design. Such a generator can be mounted on both the front and rear wheels. In the first case, the device can be combined with a built-in flashlight. To turn off the generator, a special folding mechanism is provided, which fixes the case of the generator in a position in which there is no contact with the tire or wheel rim of the bicycle.

The name of this device comes from the external similarity of the shape of the generator with the bottle. A bottle cycle generator has another name - a side dynamo. The drive rubber or metal roller is driven by contact with the side of the tire wheel. When the bicycle moves, the tire imparts rotational motion to the roller of the cycle generator, which produces electric current.

The described construction has both advantages and disadvantages. The advantages include the following features:

- Ability to disable. When the generator is on, the cyclist has to exert more force to move, and the disconnected generator drive does not resist the movement of the bicycle. The dynamo hub, unlike a bottle cycle generator, does not have the ability to turn off and provides constant resistance to the rotation of the wheel, although the value of this resistance is insignificant.

- Easy and simple installation. Such a device is easy to install on any bike, unlike a sleeve generator, for the installation of which it is necessary to assemble the entire dynamo wheel with spokes.

- Low cost. Such models are usually cheaper than other types of bicycle generators, although there are exceptions to this rule.

The disadvantages of bottle-type generators include:

- Complex setup. Careful adjustment and adjustment of contact with the tire of the wheel at a certain angle, tire pressure, height is required. If the bike falls or the fixing screws are loose, the generator may be damaged. An improperly adjusted device of the generator will make a lot of noise, create excessive resistance, slip on the wheel. If the fastening screws are too loose, the mechanism may budge and fall into the wheel spokes, which will lead to breakage of the spokes and failure of the bicycle wheel. Some cycle generators are equipped with special loops to prevent them from falling into the knitting needles.

- Physical effort is required to switch. To actuate the generator, it is necessary to move its body until it touches the wheel. Bushing generators can turn on automatically or electronically. No effort is needed for this.

Increased noise. During operation, a buzzing noise is heard, while dynamo hubs do not generate noise.

Wheel tire wear. For the operation of the generator requires contact with the tire, as a result of its wear. If you compare with the dynamo hub, then there is no friction with the tire.

Resistance to movement. The bottle dynamo exerts significantly greater resistance to the movement of the bicycle than the sleeve model. However, with the correct settings, the resistance is negligible, but is disabled when disconnected.

Slip. In wet, rainy weather, the drive roller of the bottle generator will slide along the tire of the wheel, which reduces the generation of electric current and reduces the brightness of the headlamp and rear light. Hub generators do not require good grip for the tire to operate, and are independent of weather and other adverse conditions.

A type of generator is known that is similar to a bottle one, but differs from it in that the rotation of the rotor is initiated by the contact of the drive disk with the side surface of the rim. In this case, the disk is rubberized for better adhesion to the surface of the rim, and has a diameter several times the diameter of the drive roller of a bottle-type generator.

The size of the drive disk has a significant impact on the technical characteristics of the device. To overcome the resistance of the generator, the necessary torque equal to the product of the force on the shoulder of its application must be applied to the drive disk. At the same time, the shoulder size is equal to the radius of the disk, and the force is limited by the adhesion force of the disk and rim. The adhesion force depends, inter alia, on the force with which the disk is pressed against the rim. The more force the disk is pressed, the better the grip, but the rolling friction between the disk and the rim also increases, which leads to a decrease in the efficiency of the device. Obviously, with a fixed torque, with an increase in the size of the disk, the necessary adhesion force decreases, and, consequently, the force of pressing the disk against the rim, thus, rolling friction decreases and the efficiency increases.

This type of generator is less noisy than a bottle one; it does not affect tire wear and does not depend on the pressure in it.

A known bottle type bicycle generator [US 20150229183], the drive roller of which is driven by contact with the side of the tire wheel. When the bicycle moves, the tire imparts rotational motion to the roller of the cycle generator, which produces electric current. The mounting bracket of the cycle generator allows it to be switched off (breaking the mechanical contact between the drive roller and the tire of the wheel), in cases where power generation is not required.

The disadvantage of this device is the need for contact of the drive roller of the cycle generator with the side surface of the tire wheels, which causes tire wear, as well as loud noise. In addition, as mentioned above, the small diameter of the drive roller determines a high rolling friction force between the roller and the tire.

As a prototype, a bicycle generator [KR 20140006097] was selected, consisting of a rubberized drive disk, inside of which a rotor with permanent magnets rigidly connected to it and stator coils mounted on the bicycle frame through a housing element located on the same axis with the disk and a bracket allowing the drive drive in contact with the wheel rim (the generator is working) or break the connection (the generator is off). The rotor is driven into rotation by an associated drive disk in contact with the wheel rim. During the movement of the bicycle, the rotation of the wheel causes the drive disk and the associated rotor with permanent magnets to rotate relative to the stationary stator with wire coils, which initiates the generation of electric current in the conductors of the coils.

The disadvantage of the prototype is the lack of tightness of the design of the drive disk, allowing dust and dirt to penetrate inside it, settle on wire coils, magnets, bearings and other elements and parts, increasing friction in moving parts and reducing the efficiency of the device. Also, a mud “coat” reduces heat transfer and can cause overheating of the coil conductors, and, as a result, the failure of the device.

Thus, the technical problem to which the claimed utility model is directed is the insufficient protection of parts and components of the generator from getting dirt particles on them, causing excessive friction in moving parts and overheating of the coils with wires.

The solution to this technical problem is achieved by the fact that the generator for a bicycle, containing a stator with coils, a rotor with permanent magnets, and also a drive disk connected to the rotor and rotated by contact with the wheel rim, has the following design: inside the generator body of the end type, consisting of of the cup and the hermetically sealed screw cap, the stator and rotor are mounted, the stator being located on the side of the cap and the rotor at the bottom of the cup, while the rotation from the drive disk located outside the housing is transmitted to the rotor through a magnetic coupling, in which the rotor is a driven coupling half, the bottom glass - a protective screen between the driven and the leading coupling half, and the leading coupling coupling, rotated by the drive disk, is located outside the housing in a hermetically closed cavity formed by the bottom of the glass and another screw cover. The generator housing may be made of conductive non-magnetic material (metal or alloy), for example, aluminum, or non-metallic material.

The technical result of the claimed utility model is to reduce the frictional force in moving parts, and, as a result, increase the efficiency of the device and the service life. Also, the possibility of overheating of the device due to improved conditions of heat exchange processes is excluded.

On the drawings attached to the description is given:

- a general view of a bicycle type disk generator (Fig. 1);

- mounting the generator on the bicycle frame, the relative position of the generator and the wheel (Fig. 2);

- transmission of rotation from the wheel to the drive disk (Fig. 3).

The bicycle generator 1 (Fig. 1) contains a housing 2 in the form of a cup, inside of which are located a stator 3 and a rotor 4, which is simultaneously a driven half-coupling of a magnetic coupling.

Magnetic couplings (MM) are designed to transmit torque from the drive shaft to the driven shaft without mechanical contact, through a sealing metal or non-metallic protective shield by means of a magnetic field created by a system of permanent magnets (SmCo or NdFeB) installed on the master and driven half-couplings.

It should be noted that eddy currents generated by a magnetic field in a conductive screen cause heat generation, which reduces the efficiency of a device with a magnetic drive due to "electromagnetic" losses. MMs with a nonmetallic sealing screen are deprived of this drawback [http://hydrogas.ru/production/himicheskie-nasosy/seriya-gh/germetichnye-mufryna-postoyannyh-magnitah].

The advantage of MM torque transmitters is their complete tightness, and, as a result, long-term stability of the issued characteristics, reliability and durability of operation.

The housing 2 is closed by a cover 5 screwed onto it, in the center of which there is a hole for the output of the wire 6. Coaxial with the rotor, through the sealing screen, which is the bottom of the housing 2, is the drive coupling half 7 of the magnetic coupling, closed by a cover 8 with a central hole through which the shaft connecting the leading coupling half 7 and the drive disk 9.

The generator 1 is attached via a bracket 10 (Fig. 2) to the frame 11. The bracket allows the generator to occupy two positions: in one of them, the drive disk 9 is in contact with the rim 12 of the wheel 13, in the other - the contact is broken. The position in which the drive disc 9 is in contact with the rim 12 is shown in FIG. 3.

The generator operates as follows. During the movement of the bicycle, the rotating wheel 13 transmits the rotation from the rim 12 to the drive disk 9 of the generator 1 in contact with it. The disk 9 transmits the rotation to the driving coupling half 7 of the magnetic coupling, which, in turn, rotates the rotor 4, which is the driven coupling half of the magnetic coupling. The rotor with permanent magnets rotates relative to a fixed stator with wire coils, which initiates the generation of electric current in the conductors of the coils.

As already mentioned above, the magnetic coupling transmits torque through a sealing protective shield. The material for the manufacture of this screen may be a conductive non-magnetic material (metal or alloy), for example, aluminum, or non-metal. The generator housing can be completely made of this material or only a protective shield should be made of it.

Claims (3)

1. A generator for a bicycle, comprising a stator with coils, a rotor with permanent magnets, and a drive disk connected to the rotor and rotated by contact with the wheel rim, characterized in that inside the case of the generator is an end-face type consisting of a glass and a hermetically sealed screw cover the stator and rotor are mounted, and the stator is located on the side of the lid, and the rotor is at the bottom of the cup, while the rotation from the drive disk located outside the housing is transmitted to the rotor through a magnetic coupling, in which the rotor is a driven half-coupling, the bottom of the glass is a protective screen between the driven and the leading coupling half, and the driving coupling coupling, rotated by the drive disk, is located outside the housing in a hermetically closed cavity formed by the bottom of the glass and another screw cap. 2. The generator according to claim 1, characterized in that its housing is made of a conductive non-magnetic material (metal or alloy), for example, aluminum. 3. The generator according to claim 1, characterized in that its housing is made of non-metallic material.

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