Brush direct current motor and vehicle
By installing ripples between the low -speed lines and ground lines with DC motors, the problem of high -ripple voltage on the low -speed line is solved, protecting the components in the motor and ensuring its normal operation.
Patent Information
- Application Number
- CN202421028483.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-11
- Publication Date
- 2025-01-28
- Estimated Expiration
- 2034-05-11
AI Technical Summary
In brushed DC motors, especially in wiper applications, when the high-speed line inputs a voltage of a preset amplitude and the low-speed line is suspended, very high ripple voltages may be generated on the low-speed line, resulting in frequent hits of components connected to the low-speed line Damaged through.
Install ripple inhibitory elements between the low -speed lines and ground wires with DC motors, such as electrolytic capacitors, film capacitors, or multiple multi -layer ceramic capacitors to suppress ripple voltage on the low -speed line.
By installing ripples to suppress elements, the high -ripple voltage occurs when the low -speed line input voltage is input at the low -speed line, protecting the components connected to the low -speed line to prevent it from being damaged.
Smart Images
Figure CN222423460U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a brushed DC motor and a vehicle. Background Art
[0002] A brushed DC motor is a DC motor with fixed main magnetic poles and brushes (or carbon brushes) installed on the stator, and armature windings and commutator segments installed on the rotor. The electric energy of the DC power supply enters the armature winding through the brushes and commutator segments, and the armature is subjected to the Lorentz magnetic force to generate torque, causing the motor to rotate and drive the load.
[0003] For example, a brushed DC motor can be used for a windshield wiper, where when a voltage of a preset amplitude (48V) is input to the high-speed line, the wiper runs at high speed, while the low-speed line is suspended. Similarly, when a voltage of a preset amplitude is input to the low-speed line, the wiper runs at low speed. Only one of the high-speed line and the low-speed line can be powered, otherwise it will be short-circuited.
[0004] When the wiper is running at high speed, a very high ripple voltage (eg, above 200V) will appear on the low-speed line, which may cause components connected to the low-speed line (eg, transient voltage suppression diode TVS components) to frequently break down and be damaged. Utility Model Content
[0005] The inventor of the present application realizes that when a voltage of a preset amplitude (e.g., 48V) is input to the high-speed line of a brushed DC motor and the low-speed line is suspended, a very high ripple voltage (e.g., more than 200V) may be generated on the low-speed line of the brushed DC motor. When a voltage of a preset amplitude (e.g., 48V) is input to the low-speed line and the high-speed line is suspended (e.g., when the wiper is running at a low speed), ripples will also appear on the high-speed line, but the amplitude is not high.
[0006] Specifically, refer to Figure 3 , when the carbon brush ( Figure 3 When the black block in the carbon brush moves (to the right), it contacts the first commutator segment, and the current flows through the coils on both sides of the carbon brush and returns to the negative pole of the carbon brush (see Figure 3 Then, as the carbon brush moves, when the carbon brush contacts two commutator segments (i.e., the first commutator segment and the second commutator segment) at the same time, the current still maintains its original direction due to the inductance effect (e.g., Figure 3 When the carbon brush completely leaves the first commutator segment and only contacts the second commutator segment, the coil current will suddenly change (see Figure 3 A sudden change in current will result in a ripple voltage.
[0007] Figure 44 shows a schematic diagram of a current mutation, wherein curve 420 shows a current variation curve affected only by resistance, and curve 410 shows a current variation curve affected by inductance Ls. k At this moment, the carbon brush completely leaves the previous commutator segment (ie, the first commutator segment), and a current mutation occurs (from the current value shown by the curve 410 to the current value shown by the curve 420).
[0008] Based on the foregoing understanding, according to one aspect of the utility model, a brushed DC motor is provided, the brushed DC motor comprising: a high-speed line; a low-speed line; and a ripple suppression element, the ripple suppression element being connected between the low-speed line and a ground line, and the ripple suppression element being able to suppress the ripple voltage appearing on the low-speed line when a first voltage is input to the high-speed line and the low-speed line is suspended.
[0009] As a supplement or replacement for the above solution, in the above brushed DC motor, the ripple suppression element is any one of the following: an electrolytic capacitor; a film capacitor; and a plurality of multilayer ceramic capacitors connected in parallel.
[0010] As a supplement or replacement of the above solution, in the brushed DC motor, the commutation frequency of the brushed DC motor is in the range of 600-1000 Hz. As a supplement or replacement of the above solution, in the brushed DC motor, the capacitance values of the electrolytic capacitor and the film capacitor are greater than or equal to 4.7 μF and less than 10 mF.
[0011] As a supplement or replacement for the above solution, in the above brushed DC motor, the first voltage is a 48V DC voltage.
[0012] As a supplement or replacement for the above solution, the brushed DC motor may be a wiper motor.
[0013] As a supplement or replacement for the above-mentioned scheme, the above-mentioned brushed DC motor may also include: a high-speed carbon brush connected to the high-speed line; a low-speed carbon brush connected to the low-speed line; and a commutator segment, wherein when 48V is input to the high-speed line and the low-speed line is suspended, the high-speed carbon brush moves into contact with one or two of the commutator segments, thereby conducting current to the coil winding in the brushed DC motor.
[0014] As a supplement or replacement for the above solution, the above brushed DC motor may further include: a transient voltage suppression diode TVS element, wherein the ripple suppression element is arranged in the housing of the brushed DC motor and connected in parallel with the transient voltage suppression diode TVS element.
[0015] According to another aspect of the utility model, a vehicle is provided, wherein the vehicle comprises the brushed DC motor as described above.
[0016] As a supplement or replacement for the above solution, in the above vehicle, the brushed DC motor further includes: a stop line, which is used to transmit a stop signal to the vehicle every time the wiper rotates one circle.
[0017] The brushed DC motor of an embodiment of the utility model includes a ripple suppression element, which is connected between the low-speed line and the ground line, so as to help suppress the ripple voltage appearing on the low-speed line when a first voltage (for example, 48V) is input on the high-speed line and the low-speed line is suspended, thereby ensuring that components such as TVS (transient voltage suppression diode) will not be damaged. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The above and other objects and advantages of the present invention will become more fully apparent from the following detailed description in conjunction with the accompanying drawings, wherein the same or similar elements are denoted by the same reference numerals.
[0019] Figure 1 A schematic block diagram of a brushed DC motor according to an embodiment of the utility model is shown;
[0020] Figure 2 A schematic structural diagram of a brushed DC motor (wiper motor) according to an embodiment of the utility model is shown;
[0021] Figure 3 A schematic diagram showing the principle of ripple voltage generated when a brushed DC motor is operated; and
[0022] Figure 4 A schematic diagram showing a sudden change in current in a brushed DC motor (wiper motor). DETAILED DESCRIPTION
[0023] It should be understood that the term "vehicle" or other similar terms used herein include general motor vehicles, such as passenger cars (including sports utility vehicles, buses, trucks, etc.), various commercial vehicles, ships, aircraft, etc., and include hybrid electric vehicles, electric vehicles, plug-in hybrid electric vehicles, etc. A hybrid electric vehicle is a vehicle with two or more power sources, such as gasoline-powered and electric vehicles.
[0024] It should also be noted that the terms "first", "second", etc. in the specification and claims of the present utility model are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including", "having" and similar expressions are intended to indicate non-exclusive inclusion, unless otherwise specifically indicated.
[0025] Hereinafter, exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings.
[0026] Figure 1FIG. 1 shows a brushed DC motor 1000 according to an embodiment of the present invention. The brushed DC motor 1000 comprises: a high-speed line (port) 110; a low-speed line (port) 120; and a ripple suppression element 130, wherein the ripple suppression element 130 is connected to the low-speed line 120 and the ground wire or the metal housing ( Figure 1 (not shown) and input a first voltage (eg, 48 V) to the high-speed line 110 and suppress the ripple voltage appearing on the low-speed line 120 when the low-speed line 120 is suspended.
[0027] As mentioned above, when a voltage of a preset amplitude (e.g., 48V) is input to the high-speed line of the brushed DC motor and the low-speed line is suspended, a very high ripple voltage (e.g., more than 200V) may be generated on the low-speed line of the brushed DC motor. It is understandable that the ripple voltage may increase as the voltage input to the high-speed line increases.
[0028] Specifically, refer to Figure 3 , when the carbon brush ( Figure 3 When the black block in the carbon brush moves (to the right), it contacts the first commutator segment, and the current flows through the coils on both sides of the carbon brush and returns to the negative pole of the carbon brush (see Figure 3 Then, as the carbon brush moves, when the carbon brush contacts two commutator segments (i.e., the first commutator segment and the second commutator segment) at the same time, due to the inductance effect, the current still basically maintains its original direction (such as Figure 3 When the carbon brush completely leaves the first commutator segment and only contacts the second commutator segment, the coil current will suddenly change (see Figure 3 The right picture and Figure 4 ). Sudden changes in current will cause ripple voltage.
[0029] exist Figure 4 In FIG. 4 , curve 420 shows the current variation curve affected only by the resistance, while curve 410 shows the current variation curve affected by the inductance (coil winding) Ls. k At this moment, the carbon brush completely leaves the previous commutator segment (ie, the first commutator segment), and a current sudden change occurs (ie, the current value shown by the curve 410 suddenly drops to the current value shown by the curve 420).
[0030] In one embodiment, the ripple suppression element 130 may be any one of the following: an electrolytic capacitor; a film capacitor; and a plurality of parallel multilayer ceramic capacitors. Those skilled in the art may understand that the ripple suppression element 130 is not limited to the above examples, as long as the element is connected between the low-speed line and the ground line and can effectively suppress the ripple voltage appearing on the low-speed line (thereby protecting other elements on the low-speed line).
[0031] In one embodiment, the commutation frequency of the brushed DC motor is in the range of 600-1000Hz. The so-called "commutation frequency" refers to the number of times the motor completes commutation within a certain period of time, usually in Hertz (Hz). In one embodiment, the ripple in the output voltage of the brushed DC motor is caused by the commutation of the brushed DC motor. For a brushed DC motor with a commutation frequency of 600-1000Hz, it is advantageous that the capacitance value of the electrolytic capacitor and the film capacitor is greater than or equal to 4.7μF and less than 10mF. Among them, on the one hand, the capacitance value is set to be above 4.7μF in order to effectively eliminate the ripple voltage. It can be understood that if the capacitance value of the ripple suppression element 130 is too small, it is difficult to protect the components on the low-speed line, and it itself is also easily damaged. On the other hand, setting the capacitance value to less than 10mF can effectively reduce the volume of the ripple suppression element 130 and save space on the circuit board.
[0032] In addition, the capacitance of multilayer ceramic capacitors is generally small. Therefore, in order to effectively suppress the ripple voltage appearing on the low-speed line, many multilayer ceramic capacitors need to be connected in parallel to increase the total capacitance value.
[0033] In one or more embodiments, the brushed DC motor 1000 may be a wiper motor. Figure 1 Not shown, the brushed DC motor 1000 may further include: a high-speed carbon brush connected to the high-speed line 110; a low-speed carbon brush connected to the low-speed line 120; and a commutator segment, wherein when 48V is input to the high-speed line 110 and the low-speed line 120 is suspended, the high-speed carbon brush moves into contact with one or two of the commutator segments, thereby conducting current to the coil winding in the brushed DC motor 1000.
[0034] Figure 2 FIG. 2 shows a schematic diagram of the structure of a wiper motor (platform) 2000 according to an embodiment of the present utility model. Figure 2 As shown, 53b is the high-speed line (port), 53 is the low-speed line (port), 31b is the stop line (port) and 31 is the ground line (the ground line 31 is also connected to the metal shell of the wiper). When 48V of electricity is supplied to the high-speed line 53b, the wiper runs at high speed. At this time, the low-speed line 53 is suspended, and ripples will appear on the low-speed line 53 at this time, and the amplitude is very high. When 48V of electricity is supplied to the low-speed line 53, the wiper runs at low speed. At this time, the high-speed line is suspended, and ripples will also appear on the high-speed line 53b, but the amplitude is not high. It should be noted that only one of the high-speed line 53b and the low-speed line 53 can be powered, otherwise there will be a short circuit.
[0035] Continue to refer Figure 2, the high-speed line 53b is coupled to the motor M via the inductor 232, and the low-speed line 53 is coupled to the motor M via the inductor 234. 236 shows a stop signal, which is intermittent. Every time the wiper rotates one circle (i.e., the wiper rotates one circle from the stop position and returns to the stop position again), a signal (i.e., the stop signal) is sent to the vehicle. The stop signal is used to notify the vehicle (the wiper has reached the stop position) to facilitate subsequent control.
[0036] exist Figure 2 The figure also schematically shows the components (such as the small filter capacitor 212 and the transient voltage suppression diode 214) connected between the housing 240 and the high-speed line 53b, and the components (including the ripple suppression component 220, the transient voltage suppression diode 216 and the small filter capacitor 218) connected between the housing 240 and the low-speed line 53. It can be seen that the ripple suppression component 220 is located inside the housing 240, and the transient voltage suppression diode 216 is connected in parallel with the ripple suppression component 220. Due to the presence of the ripple suppression component 220, when the first voltage (for example, 48V) is input to the high-speed line 53b and the low-speed line 53 is suspended, the ripple voltage appearing on the low-speed line 53 can be effectively suppressed, so that other components (including but not limited to the transient voltage suppression diode 216) connected between the housing 240 and the low-speed line 53 can be protected and avoid damage.
[0037] In summary, the brushed DC motor of the utility model includes a ripple suppression element, which is connected between the low-speed line and the ground line, so as to help suppress the ripple voltage appearing on the low-speed line when the first voltage (for example, 48V) is input on the high-speed line and the low-speed line is suspended, thereby ensuring that components such as TVS (transient voltage suppression diode) will not be damaged.
[0038] The above examples mainly illustrate the brushed DC motor and vehicle of the present invention. Although only some of the embodiments of the present invention are described, it should be understood by those skilled in the art that the present invention can be implemented in many other forms without departing from its subject matter and scope. Therefore, the examples and embodiments shown are considered to be illustrative rather than restrictive, and the present invention may cover various modifications and substitutions without departing from the spirit and scope of the present invention as defined in the appended claims.
Claims
1. A brushed DC motor, characterized in that: The brushed DC motor comprises: High-speed line; Low speed lines; and A ripple suppression element is connected between the low-speed line and the ground line, and the ripple suppression element suppresses the ripple voltage appearing on the low-speed line when a first voltage is input to the high-speed line and the low-speed line is suspended.
2. The brushed DC motor according to claim 1, wherein: The ripple suppression element is any one of the following: Electrolytic capacitors; Film capacitors; as well as Multiple multilayer ceramic capacitors connected in parallel.
3. The brushed DC motor according to claim 2, wherein: The commutation frequency of the brushed DC motor is in the range of 600-1000 Hz.
4. The brushed DC motor according to claim 3, wherein: The capacitance values of the electrolytic capacitor and the film capacitor are greater than or equal to 4.7 μF and less than 10 mF.
5. The brushed DC motor according to claim 1, wherein: The first voltage is a 48V DC voltage.
6. The brushed DC motor according to claim 1 or 5, wherein: The brushed DC motor is a wiper motor.
7. The brushed DC motor according to claim 6, further comprising: A high-speed carbon brush connected to the high-speed line; A low-speed carbon brush connected to the low-speed line; as well as Commutator segment, When 48V is input to the high-speed line and the low-speed line is suspended, the high-speed carbon brush moves into contact with one or two of the commutator segments, thereby conducting current to the coil winding in the brushed DC motor.
8. The brushed DC motor according to claim 1, further comprising: Transient voltage suppression diode TVS components, Wherein, the ripple suppression element is arranged in the housing of the brushed DC motor and is connected in parallel with the transient voltage suppression diode TVS element.
9. A vehicle, characterized in that: The vehicle comprises a brushed DC motor as claimed in any one of claims 1 to 8.
10. The vehicle of claim 9, wherein the brushed DC motor further comprises: The parking line is used to transmit a parking signal to the vehicle every time the wiper rotates one circle.