Direct current motor additionally provided with damping winding

Abstract

The invention relates to a direct current motor additionally provided with a damping winding, the direct current motor comprises a stator part and a rotor part, the stator part comprises a stator base, a stator iron core and at least one pair of stator magnetic poles, the stator iron core is fixedly arranged in the stator base, and each stator magnetic pole is fixedly arranged in the stator iron core; the motor also comprises a damping winding which comprises at least one pair of damping coils which are respectively arranged outside each stator magnetic pole in a surrounding manner, or a damping cage which is arranged outside all the stator magnetic poles in a surrounding manner. The damping windings are additionally arranged on the stator magnetic poles of the direct current motor, commutation can be effectively improved, electromagnetic interference can be effectively reduced, and the electromagnetic compatibility of the direct current motor is improved. The motor can be widely applied to the technical field of motors.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a DC motor with added damping windings, and particularly to a DC motor with added damping windings to improve commutation and reduce electromagnetic interference. Background Technology

[0002] Modern society is inseparable from electric motors, whose applications are ubiquitous in transportation, industrial and agricultural production, information processing, and all aspects of daily life. There are many types of electric motors, each with a different structure, including DC motors, asynchronous motors, permanent magnet motors, and electrically excited motors. Each type of motor has its own characteristics and is widely used in different applications.

[0003] DC motors have gained attention and use due to their numerous advantages, such as excellent speed regulation performance, high starting torque, simple control, and compatibility with DC power supplies. However, DC motors contain components such as commutators and brushes, and undergo a mechanical commutation process. The friction between the brushes and the commutator, as well as the commutation process itself, can generate sparks, potentially leading to electromagnetic interference, damage to the oxide film on the commutator surface, and abnormal wear.

[0004] Electronic devices are now ubiquitous, and electromagnetic interference caused by commutation threatens their safety. This places stricter demands on the electromagnetic compatibility (EMC) performance of DC motors. How to mitigate EMC caused by DC motor commutation remains a challenge, and reducing motor EMC is of paramount importance. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a DC motor equipped with a damping winding, which can effectively improve commutation and reduce electromagnetic interference.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A DC motor equipped with a damping winding includes a stator section and a rotor section. The stator section includes a stator frame, a stator core, and at least one pair of stator poles. The stator core is fixedly disposed within the stator frame, and each stator pole is fixedly disposed within the stator core. The motor also includes: Damping winding, including: Several damping coils are respectively arranged around each of the stator magnetic poles; Alternatively, a damping cage may be placed outside all of the stator poles.

[0007] Furthermore, the damping coil is formed by sequentially connecting the first to fourth coil sides, with the first and third coil sides arranged axially and the second and fourth coil sides arranged circumferentially.

[0008] Furthermore, the span of the damping coil on the circumference is set according to actual needs, including: It is set to have the same span as the rotor armature winding coils that are short-circuited by brushes for commutation within the rotor section; Alternatively, set it to polar distance; Alternatively, it can be set to be the same as the span of the stator poles; Alternatively, set it to be greater than the polar distance.

[0009] Furthermore, the position of the coil side of the damping coil on the circumference is set as follows: Corresponding to the coil side of the rotor armature winding in commutation; Alternatively, the centerline of the damping coil is aligned with the centerline of the stator magnetic pole; Alternatively, the centerline of the damping coil may be deflected at a predetermined angle relative to the centerline of the stator magnetic poles based on the sparking conditions.

[0010] Furthermore, the damping cage includes a first damping ring, a second damping ring, and a plurality of damping strips; The first damping ring and the second damping ring are respectively disposed at both ends of the stator magnetic pole along the axial direction; Each of the damping strips is disposed between the first damping ring and the second damping ring, and is short-circuited by the first damping ring and the second damping ring.

[0011] Furthermore, the span of each damping strip is set according to actual needs, including: When two damping bars are set under each pole, the span between the two damping bars is set to be the same as the span of the rotor armature winding coil that is short-circuited by the brush for commutation. Alternatively, the span can be set to be the same as that of the stator poles; when a damping bar is set under each pole, the span between adjacent damping bars is set as the pole pitch. Alternatively, it can be set to be greater than the polar distance.

[0012] Furthermore, the location of the damping strip includes: When the number of damping bars under each pole is greater than two, the position of the damping bars should be set reasonably according to the needs. Alternatively, the position of the damping bar on the circumference corresponds to the position of the coil side of the rotor commutation armature coil; Alternatively, the damping bars under each pole are arranged symmetrically with respect to the center line of the stator poles; Alternatively, the centerline of the damping bar under each pole may be deflected at a preset angle relative to the centerline of the stator pole, depending on the sparking conditions.

[0013] Furthermore, the damping coil or damping cage is connected to a high-pass filter to filter out or dampen rapidly changing current. Alternatively, the damping coil or damping cage can be connected to a capacitor to achieve a band-pass effect.

[0014] Furthermore, the damping coil or damping cage is made of copper or aluminum.

[0015] Furthermore, when the stator magnetic poles are composed of magnetic poles divided into blocks along the circumferential direction, the damping windings are arranged in the space between the blocks, surrounding the divided magnetic poles as units.

[0016] The present invention has the following advantages due to the adoption of the above technical solutions: 1. By adding damping windings to the stator magnetic poles of the DC motor, this invention can effectively improve commutation, reduce electromagnetic interference, and improve the electromagnetic compatibility performance of the DC motor.

[0017] 2. The damping winding coil, which is set separately around the stator magnetic poles in this invention, can be connected to a high-pass filter to impede rapidly changing current.

[0018] 3. The damping winding coil, which is set separately around the stator magnetic poles in this invention, can be connected to a capacitor to achieve a band-pass effect and impede the current change in a certain frequency range.

[0019] Based on the above advantages, this invention can be widely applied to DC motor systems in household appliances, medical instruments, industrial production, manufacturing and civilian fields, aerospace motor and electrical equipment, ship auxiliary machinery and ship propulsion systems, and mobile electrical systems, and is of great significance for reducing electromagnetic interference in systems. Attached Figure Description

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of the cross-section of an existing permanent magnet DC motor. Figure 2 BB cross-section image; Figure 2 This is a schematic diagram of the axial cross-section of an existing permanent magnet DC motor. Figure 1 AA section diagram; Figure 3 This is a cross-sectional schematic diagram of the permanent magnet DC motor in an embodiment of the present invention. Figure 4 BB cross-section image; Figure 4 This is a schematic diagram of the axial cross-section of the permanent magnet DC motor in an embodiment of the present invention. Figure 3 AA section diagram; Figure 5 This is a schematic diagram of the damping winding structure in an embodiment of the present invention; Figure 6 This is another schematic diagram of the damping winding structure in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0023] like Figure 1 and Figure 2 The diagram shows the structure of an existing permanent magnet DC motor, with only a two-pole motor as an example. This DC motor includes a stator and a rotor. The stator generates a magnetic field, converting electrical energy into mechanical energy; the rotor is located within the stator and works in conjunction with it to achieve energy conversion.

[0024] The stator section includes a stator frame 1, a stator core 2, and stator poles 3. The stator frame 1 is fixed in a conventional motor mounting manner, the stator core 2 is fixedly installed inside the stator frame 1, and the stator core 2 is part of the motor's magnetic circuit; the stator poles 3 are fixedly installed inside the stator core 2.

[0025] The rotor section includes a rotor core 4, a rotor shaft 5, bearings 6, rotor armature windings 7, and a commutator 8. The rotor core 4 is fixedly mounted on the rotor shaft 5, located between the N and S poles of the stator magnetic poles 3. The rotor shaft 5 is fixedly mounted on the stator frame 1 via bearings 6, enabling the rotor core 4 to rotate around its axis. Several grooves (not shown in the figure) are evenly distributed on the outer circumference of the rotor core 4, and the rotor armature windings 7 are disposed within these grooves. The commutator 8 is located on one or both sides of the rotor core 4 on the rotor shaft 5. Each coil in the rotor armature windings 7 is connected to the commutator 8 and then connected to an external static power supply circuit via brushes (not shown in the figure).

[0026] DC motors have a commutator and brushes that slide in contact. When the rotor armature winding 7 passes through the brushes, the direction of the current changes rapidly, causing high-frequency electromagnetic interference. If the commutation is not ideal, sparks can also occur between the brushes and the commutator, further contributing to electromagnetic interference. All of these electromagnetic interferences pose risks to the operation of surrounding electronic equipment and require improvement.

[0027] Analysis of existing DC motors reveals that commutation sparks between the brushes and commutator occur because the circuit formed by the brushes and commutation coils is suddenly broken, leading to a rapid change in current. Based on this principle, some embodiments of this invention propose a DC motor with added damping windings. By adding damping windings to the stator, commutation can be effectively improved, electromagnetic interference reduced, and the electromagnetic compatibility performance of the DC motor enhanced.

[0028] Example 1 like Figure 3 and Figure 4 As shown, the present invention provides a DC motor with a damping winding, comprising: a stator section, a rotor section, and a damping winding 9. The stator section includes a stator frame 1, a stator core 2, and stator poles 3; the damping winding 9 is arranged around the stator poles 3 to improve commutation and reduce electromagnetic interference.

[0029] Furthermore, such as Figure 5 As shown, the damping winding 9 can be composed of several damping coils respectively surrounding each stator magnetic pole 3. Figure 5 The image shows two damping coils. One damping coil is formed by connecting coil edges 101, 102, 103, and 104 in sequence, with coil edges 101 and 103 arranged axially and coil edges 102 and 104 arranged circumferentially. The other damping coil is formed by connecting coil edges 105, 106, 107, and 108 in sequence, with coil edges 105 and 107 arranged axially and coil edges 106 and 108 arranged circumferentially.

[0030] Furthermore, the span of the damping coil on the circumference (i.e., the span of the coil in coil edges 102 and 104) can be set according to actual conditions, for example: Preferably, the span of the rotor armature winding 7 is the same as that of the coils that are commutated by short-circuiting the brushes; in particular, since the span of the rotor armature winding 7 is usually set as the pole pitch, i.e. the whole pitch, in order to improve the winding utilization rate of the DC motor, the span of the damping coil on the circumference can also be set as the pole pitch. If there are other limiting factors, the span of the damping coil can be appropriately reduced according to the actual situation, but the damping effect will be weakened, so it must be increased as much as possible; To reduce the amount of copper used in the coil, the span of the damping coil on the circumference can also be set to be the same as the span of the stator pole 3. The span of the damping coil on the circumference can also be chosen to be greater than the pole pitch, making it a long-pitch coil.

[0031] Furthermore, the position of the coil side of the damping coil on the circumference is set as follows: Corresponding to the coil side of the rotor armature winding 7 in commutation; Alternatively, the center line of the damping coil is aligned with the center line of stator pole 3; Alternatively, the center line of the damping coil may be deflected at an angle relative to the center line of stator pole 3, depending on the sparking situation.

[0032] Furthermore, the number of turns of the damping coil can be set as needed. Of course, the damping coil per pole described above can be split into multiple equivalent damping coils.

[0033] Furthermore, such as Figure 6 As shown, the damping winding 9 can also be a damping cage surrounding all the stator poles 3. The damping cage includes a first damping ring 202, a second damping ring 204, and several damping bars. The first damping ring 202 and the second damping ring 204 are respectively arranged axially at both ends of the stator poles 3, and each damping bar is arranged between the first damping ring 202 and the second damping ring 204 and short-circuited by the first damping ring 202 and the second damping ring 204.

[0034] Furthermore, the number of damping strips is set according to the actual situation. Figure 6 In the example of setting one damping bar under each pole, it includes a first damping bar 201 and a second damping bar 203.

[0035] Furthermore, the span of each damping strip is set according to actual needs, for example: When two damping bars are set under each pole, the span of the two damping bars surrounding the stator pole 3 is preferably the same as the span of the rotor armature winding 7 coil that is short-circuited by the brush for commutation. Alternatively, the span can be set to be the same as that of the stator poles; when a damping bar is set under each pole, the span between adjacent damping bars is set as the pole pitch. In particular, if the position of the damping bars is restricted, the span between the two damping bars surrounding the stator pole 3 can be appropriately reduced according to the actual situation, but the damping effect will be weakened, so it must be increased as much as possible; The span of the damping strip can also be selected to be greater than the electrode pitch, which is a long span.

[0036] Furthermore, the position of the damping strip can be set appropriately according to needs: When the number of damping bars under each pole is greater than two, the position of the damping bars can be reasonably set as needed; The position of the damping bar on the circumference preferably corresponds to the position of the coil side in the rotor armature winding 7 that is short-circuited by the brush for commutation; secondly, the arrangement of the damping bar under each pole can be symmetrical about the center line of the stator magnetic pole 3; furthermore, the center line of the damping bar under each pole can be appropriately deflected from the center line of the stator magnetic pole according to the spark situation.

[0037] During commutation, the current in the short-circuit coil changes rapidly. This current establishes a rapidly changing magnetic field in the motor's magnetic circuit. This rapidly changing magnetic field generates a current in the damping winding, which impedes the rapid change in the short-circuit coil current, thus weakening its rapid change and reducing electromagnetic interference. Neither permanent magnet DC motors nor electrically excited DC motors have a mechanism to mitigate this source of electromagnetic interference.

[0038] Furthermore, to enhance the damping effect, in this embodiment, the damping coil separately arranged around the stator magnetic pole 3 can be connected to a high-pass filter, or a high-pass filter can be connected at a suitable position in the damping cage to impede rapidly changing currents while having a weaker effect on slowly changing currents.

[0039] Furthermore, to make the damping effect more targeted and simplify the setup, the damping coil set separately around the stator magnetic pole 3 can be connected to a capacitor, or a capacitor can be connected at a suitable position in the damping cage to achieve a band-pass effect, thereby hindering the current change in a certain frequency range while having a weaker effect on the current at other frequencies.

[0040] Furthermore, the axial length of the damping coil is preferably greater than the axial length of the stator pole 3 and the rotor armature winding 7. It can be appropriately shortened when there are limitations, but it should be as long as possible.

[0041] Furthermore, if the stator magnetic pole 3 is composed of blocks along the circumferential direction, and the space between the blocks is left open to arrange the damping winding, the damping winding will treat the block magnetic pole as a unit to surround and form the damping winding.

[0042] Furthermore, the damping coil or damping cage can be made of copper or aluminum.

[0043] The embodiments described in this invention use a permanent magnet DC motor as an example, but the invention is also applicable to electrically excited DC motors and AC / DC universal motors.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A DC motor equipped with a damping winding, comprising a stator portion and a rotor portion, wherein the stator portion includes a stator frame, a stator core, and at least one pair of stator poles, the stator core being fixedly disposed within the stator frame, and each of the stator poles being fixedly disposed within the stator core; characterized in that, Also includes: Damping winding, including: Several damping coils are respectively arranged around each of the stator magnetic poles; Alternatively, a damping cage may be placed outside all of the stator poles.

2. A DC motor with added damping winding as described in claim 1, characterized in that, include: The damping coil is formed by sequentially connecting the first to fourth coil sides, with the first and third coil sides arranged axially and the second and fourth coil sides arranged circumferentially.

3. A DC motor with added damping winding as described in claim 2, characterized in that, The span of the damping coil on the circumference is set according to actual requirements, including: It is set to have the same span as the rotor armature winding coils that are short-circuited by brushes for commutation within the rotor section; Alternatively, set it to polar distance; Alternatively, it can be set to be the same as the span of the stator poles; Alternatively, set it to be greater than the polar distance.

4. A DC motor with added damping winding as described in claim 2, characterized in that, The position of the coil side of the damping coil on the circumference is set as follows: Corresponding to the coil side of the rotor armature winding in commutation; Alternatively, the centerline of the damping coil is aligned with the centerline of the stator magnetic pole; Alternatively, the centerline of the damping coil may be deflected at a predetermined angle relative to the centerline of the stator magnetic poles based on the sparking conditions.

5. A DC motor with added damping winding as described in claim 1, characterized in that, The damping cage includes a first damping ring, a second damping ring, and several damping bars; The first damping ring and the second damping ring are respectively disposed at both ends of the stator magnetic pole along the axial direction; Each of the damping strips is disposed between the first damping ring and the second damping ring, and is short-circuited by the first damping ring and the second damping ring.

6. A DC motor with added damping winding as described in claim 5, characterized in that, The span of each damping strip is set according to actual needs, including: When two damping bars are set under each pole, the span between the two damping bars is set to be the same as the span of the rotor armature winding coil that is short-circuited by the brush for commutation. Alternatively, it can be set to be the same as the span of the stator poles; When a damping bar is set under each pole, the span between adjacent damping bars is set as the pole pitch; Alternatively, it can be set to be greater than the polar distance.

7. A DC motor with added damping winding as described in claim 5, characterized in that, The damping strip is positioned at the following locations: When the number of damping bars under each pole is greater than two, the position of the damping bars should be set reasonably according to the needs. Alternatively, the position of the damping bar on the circumference corresponds to the position of the coil side of the rotor commutation armature coil; Alternatively, the damping bars under each pole are arranged symmetrically with respect to the center line of the stator poles; Alternatively, the centerline of the damping bar under each pole may be deflected at a preset angle relative to the centerline of the stator pole, depending on the sparking conditions.

8. A DC motor with added damping winding as described in claim 1, characterized in that, The damping coil or damping cage is connected to a high-pass filter to filter out or dampen rapidly changing current. Alternatively, the damping coil or damping cage may be connected to a capacitor to achieve a bandpass effect.

9. A DC motor with added damping winding as described in claim 1, characterized in that, The damping coil or damping cage is made of copper or aluminum.

10. A DC motor with added damping winding as described in claim 1, characterized in that, When the stator magnetic poles are composed of magnetic poles divided into blocks along the circumferential direction, the damping windings are arranged in the space between the blocks, surrounding the divided magnetic poles as units.

Images