DC generator

Abstract

The present invention discloses a DC generator, belonging to the field of power generation: aiming to provide a DC generator which, when in operation, when the magnetic flux passing through the armature winding increases, that is, when the induced current generated by the armature winding increases from small to large, the magnetic field generated by the induced current of the armature winding and the excitation magnetic field cancel each other out and do not hinder the rotation of the generator rotor, and can save about 30% energy compared with the existing generators. The key points of its technical solution are: the stator core structure is a non-branched magnetic circuit core, there is an air gap in the magnetic circuit, both the excitation and the armature winding are installed on the stator core, and a magnetic material block corresponding to the air gap is installed on the rotating shaft. When the rotating shaft rotates and the magnetic material block enters the air gap, the magnetic resistance of the stator core magnetic circuit decreases, the magnetic flux of the stator core magnetic circuit increases, and the armature winding generates an induced current. When the magnetic material block leaves the air gap, the magnetic resistance of the stator core magnetic circuit increases, the magnetic flux of the stator core magnetic circuit decreases, and the armature winding generates an induced current.

Description

Technical Field

[0001] The present invention relates to a DC generator, and more particularly to a DC generator with a changing magnitude but a constant direction. Background Art

[0002] Existing generators include AC generators and DC generators. There are two types of generators: rotating magnetic pole type and rotating armature type. When the generator is in operation, as long as the armature winding generates an induced current, the magnetic field generated by the induced current always repels or attracts the magnetic field of the excitation, hindering the rotation of the generator rotor. This results in high energy consumption. Summary of the Invention

[0003] The object of the present invention is to overcome the deficiencies in the prior art and provide a DC generator. When the magnetic flux passing through the armature winding increases during operation, that is, when the induced current generated by the armature winding increases from small to large, the magnetic field generated by the induced current in the armature winding does not hinder the rotation of the generator rotor. When the magnetic flux passing through the armature winding decreases, that is, when the induced current generated by the armature winding decreases from large to small, the magnetic field generated by the induced current in the armature winding and the magnetic field of the excitation add up to generate a magnetic attraction force that attracts the magnetic material block on the generator shaft to hinder the rotation of the generator rotor. A relatively energy-saving DC generator is provided.

[0004] To achieve the above object, the present invention is realized through the following solutions.

[0005] The DC generator of the present invention includes a stator and a rotor. The stator core structure is a non-branched magnetic circuit core with an air gap opened in the magnetic circuit. Both the excitation and the armature windings are installed on the stator core. A magnetic material block corresponding to the air gap is installed on the rotating shaft. When the rotating shaft rotates and the magnetic material block enters the air gap, the magnetic resistance of the stator core magnetic circuit decreases, the magnetic flux of the stator core magnetic circuit increases, and the armature winding generates an induced current. When the magnetic material block leaves the air gap, the magnetic resistance of the stator core magnetic circuit increases, the magnetic flux of the stator core magnetic circuit decreases, and the armature winding generates an induced current. The excitation of the DC generator is to install a coil on the stator core to conduct direct current for excitation. The excitation of the DC generator can use a permanent magnet for excitation. The stator core of the DC generator can be rectangular. The stator core of the DC generator can be square. The stator core of the DC generator can be circular or other shapes.

[0006] The DC generator of the present invention can save about 30% of energy compared with existing generators. Brief Description of the Drawings

[0007] Figure (1) is a front view of the rotor magnetic material of the DC generator of the present invention within the air gap.

[0008] Figure (2) is a top view of Figure (1) of the DC generator of the present invention.

[0009] Figure (3) is the left view of the DC generator in Figure (1) of the present invention.

[0010] Figure (4) is the front view of the DC generator rotor of the present invention when the magnetic material block is 90° away from the air gap.

[0011] Figure (5) is the top view of the DC generator in Figure (4) of the present invention.

[0012] Figure (6) is the left view of the DC generator in Figure (4) of the present invention. Detailed implementation mode

[0013] The following is a further description in conjunction with the accompanying drawings.

[0014] The DC generator mainly consists of a stator and a rotor.

[0015] The stator is composed of three components: a stator core 6, an exciting winding 3, and an armature winding 4.

[0016] The stator core 6 is a rectangular non-branched magnetic circuit core. There is an air gap 8 in the magnetic circuit. Both the exciting winding 3 and the armature winding 4 are installed on the iron cores on both sides of the air gap 8, and the armature winding 4 is installed outside the exciting winding 3. The magnetic fluxes of the two exciting windings 3 on the stator core 6 assist each other.

[0017] The rotor mainly consists of four components: a rotating shaft 5, a convex block 7, a non-magnetic insulating material block 2, and a magnetic material block 1. The convex blocks 7 are installed on both sides symmetrically with respect to the rotating shaft 5. The magnetic material 1 is installed on the convex blocks 7, and a non-magnetic insulating material block 2 is padded between the magnetic material block 1 and the convex blocks 7. The shape and size of the magnetic material block 1 should be determined according to the iron cores on both sides of the air gap 8, and the thickness is slightly less than the width of the air gap 8.

[0018] Permanent magnets can also be used for excitation.

[0019] The size of the air gap 8 should be calculated and determined according to Ohm's law of the magnetic circuit. When the magnetic material block 1 is not in the air gap 8, the magnetic resistance of the magnetic circuit of the stator core 6 should be very large and the magnetic flux should be very small.

[0020] The stator core 6 and the magnetic material block 1 should be made of soft magnetic materials with high magnetic permeability and small eddy currents.

[0021] The stator core 6 can be made of iron cores in shapes such as rectangular, square, circular, etc.

[0022] Functions of the non-magnetic material 2: When the magnetic material block 1 enters the air gap 8, ① prevent the magnetic field of the excitation from directly entering the convex block 7 to form another magnetic circuit. ② The convex block 7 approaches the magnetic fields of the iron cores on both sides of the air gap 8, and eddy currents are generated in the convex block 7 during the operation of the generator. Therefore, the non-magnetic insulating material block 2 should have a certain thickness.

[0023] The DC generator consists of a stator and a rotor in the following manner.

[0024] After assembling the stator and rotor of the DC generator as described above, install the rotor, and install the two stators on the symmetric two sides of the rotor. The air gap 8 corresponds to the magnetic material block 1, that is, when the rotating shaft rotates, the magnetic material block 1 should enter and exit the air gap 8 without friction.

[0025] Operating principle of the DC generator: Pass direct current through the exciting winding 3 for excitation, and drive it with a prime mover. When the magnetic material block 1 enters the air gap 8, since the magnetic permeability of the magnetic material block 1 is many times larger than that of air, the magnetic resistance of the magnetic circuit of the stator core 6 is reduced by many times. According to Ohm's law of the magnetic circuit, the magnetic flux of the magnetic circuit of the stator core 6 increases. According to the electromagnetic induction law, the armature winding 4 installed on the stator core 6 generates an induced current. Similarly, when the magnetic material block 1 leaves the air gap 8, the magnetic resistance of the magnetic circuit of the stator core 6 increases, the magnetic flux of the magnetic circuit of the stator core 6 decreases, and the armature winding 4 generates an induced current.

[0026] Analysis of generator operation:

[0027] The DC generator is energized for excitation. On both sides of the air gap 8, one side of the iron core is the south pole of excitation, and the other side is the north pole. When the generator is operating under no-load conditions, the magnetic material block 1 rotates towards the air gap 8, and the magnetic attraction of the exciting magnetic field attracts the magnetic material block 1 to move towards the air gap 8. When the magnetic material block 1 leaves the air gap 8, the magnetic attraction of the exciting magnetic field attracts the magnetic material block 1, hindering the rotation of the generator rotor.

[0028] When the generator is connected to a load and the magnetic material block 1 rotates towards the air gap 8, the magnetic flux passing through the armature winding 4 increases, that is, when the induced current generated by the armature winding 4 increases from small to large, according to Lenz's law, the direction of the magnetic field generated by the induced current in the armature winding 4 is opposite to the direction of the magnetic field of the exciting winding 3. In the same magnetic circuit, the two magnetic field directions are opposite, and they cancel each other out. When the magnetic field generated by the exciting winding 3 is greater than or equal to the magnetic field generated by the induced current in the armature winding 4, the magnetic induction intensity in the magnetic circuit of the stator core 6 also weakens or does not show magnetism externally. The magnetic induction intensity on both sides of the air gap 8 also weakens or does not show magnetism externally. Obviously, when the magnetic material block 1 rotates towards the air gap 8, the magnetic field generated by the induced current in the armature winding 4 and the magnetic field of the exciting winding 3 do not hinder the rotation of the generator rotor.

[0029] When the magnetic material block 1 leaves the air gap 8, the magnetic flux passing through the armature winding 4 decreases, that is, when the induced current generated by the armature winding 4 decreases from large to small, according to Lenz's law, the direction of the magnetic field generated by the induced current in the armature winding 4 is the same as the direction of the magnetic field of the exciting winding 3. The magnetic attraction generated by the combined magnetic fields of the exciting winding 3 and the armature winding 4 attracts the magnetic material block 1, hindering the rotation of the generator rotor.

[0030] Compared with existing generators, the DC generator of the present invention can save about 30% of energy. The main reasons are as follows: ① When the induced current generated by the armature winding 4 of the DC generator of the present invention increases from small to large, the magnetic field generated by the induced current of the armature winding 4 and the magnetic field generated by the exciting winding 3 cancel each other out and do not hinder the rotation of the generator rotor. ② The magnetic field inside the energized stator core 6 is already close to saturation. When the induced current generated by the armature winding 4 decreases from large to small, the change in the magnetic induction intensity of the stator core 6 is relatively slow.

[0031] According to the technical solution of the DC generator of the present invention, generators with many variant structures can be produced to meet the needs of the power generation industry.

Claims

1. A DC generator includes a stator and a rotor, characterized in that, the stator core structure is a non-branched magnetic circuit core, there is an air gap in the magnetic circuit, the exciting winding and the armature winding are both installed on the stator core, a magnetic material block corresponding to the air gap is installed on the rotating shaft. When the magnetic material block on the rotating shaft enters the air gap, the magnetic resistance of the stator core magnetic circuit decreases, the magnetic flux of the stator core magnetic circuit increases, and the armature winding generates an induced current. When the magnetic material block leaves the air gap, the magnetic resistance of the stator core magnetic circuit increases, the magnetic flux of the stator core magnetic circuit decreases, and the armature winding generates an induced current; wherein, the rotor is mainly composed of four components: a rotating shaft, a convex block, a non-magnetic insulating material block and a magnetic material block; the convex blocks are installed on both sides symmetrically of the rotating shaft, the magnetic material is installed on the convex blocks, and a non-magnetic insulating material block is padded between the magnetic material block and the convex block; the function of the non-magnetic insulating material block is: when the magnetic material block enters the air gap: prevent the magnetic field of the excitation from directly entering the convex block to form another magnetic circuit; the convex block approaches the magnetic fields of the iron cores on both sides of the air gap, and eddy currents are generated on the convex block during the operation of the generator.

2. The DC generator according to claim 1, characterized in that a coil is installed on the stator core to conduct direct current for excitation.

3. The DC generator according to claim 1, characterized in that a permanent magnet can be used for excitation.

4. The DC generator according to claim 1, characterized in that the stator core can be rectangular.

5. The DC generator according to claim 1, characterized in that the stator core can be square.

6. The DC generator according to claim 1, characterized in that the stator core can be circular or other shapes.

Images