Electric Motor
By forming a discharge pattern on the electronic substrate and setting a capacitor, the fault problem caused by electrostatic discharge in the motor is solved, effective suppression of static electricity and protection of electronic components are achieved, and the casing size is reduced.
Patent Information
- Application Number
- CN202011171088.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2019-12-02
- Filing Date
- 2020-10-28
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2040-10-28
AI Technical Summary
In a motor, when the shaft passes through the electronic substrate, due to electrostatic discharge, components such as integrated circuits that are not resistant to static electricity may break down, causing failure or malfunction.
A specific discharge pattern is formed on the electronic substrate, closer to the charged electrostatic member, formed through a through hole, for discharge of electrostatic electricity, and a capacitor is provided on the positive or negative electrode side of the power supply to ensure the path of electrostatic discharge and protect the electronic components.
Effectively suppress electronic component failures or electronic circuit malfunctions caused by static electricity, reduce housing size, and protect electronic substrates through multiple discharge patterns and capacitors.
Smart Images
Figure CN112994361B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an electric motor (in other words, a motor) including a substrate. Background Art
[0002] Some electric motors have an electronic substrate built in or attached thereto. In order to reduce the size of the housing of such electric motors, there is a proposal that a shaft passes through the electronic substrate (for example, refer to Patent Document 1 listed below).
[0003] Prior Art Literature
[0004] Patent Literature
[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-131079
[0006] However, in the case of a fan made of resin mounted on a shaft and the shaft being charged with static electricity, if there are signal lines around the through-portion of the shaft in the electronic substrate, static discharge may cause component breakdown in parts that are not resistant to static electricity, such as an integrated circuit (IC). Summary of the invention
[0007] (1) The motor disclosed herein comprises a substrate, characterized in that it comprises: a first circuit pattern which connects specific electronic components in the substrate; and a second circuit pattern which is formed in the substrate at a position closer to a component of the motor charged with static electricity than the distance between the first circuit pattern and the component, and is used to discharge the static electricity.
[0008] (2) Preferably, the member is a shaft provided in the motor so as to pass through the substrate.
[0009] (3) Preferably, the second circuit pattern is formed on the substrate through a through hole.
[0010] (4) Preferably, a plurality of the second circuit patterns are formed on the substrate.
[0011] (5) Preferably, the second circuit pattern discharges the static electricity toward a positive electrode side or a negative electrode side of a power source in the substrate.
[0012] (6) Preferably, in the substrate, a capacitor is provided between the second circuit pattern and the positive electrode side or the negative electrode side.
[0013] (7) Preferably, a difference between a distance between the member and the first circuit pattern and a distance between the member and the second circuit pattern is 0.3 mm or more.
[0014] Effects of the Invention
[0015] According to the disclosed motor, it is possible to suppress failure of electronic components or malfunction of electronic circuits due to static electricity. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is an exploded perspective view of the electric motor according to the embodiment.
[0017] Figure 2 yes Figure 1 A schematic cross-sectional view of the electric motor is shown.
[0018] Figure 3 yes Figure 1 Surface image of an electronic substrate shown.
[0019] Figure 4 yes Figure 1 Back view of the electronic substrate shown.
[0020] Figure 5 (a), (b), (c), and (d) are Figure 3 as well as Figure 4 The circuit diagram of the electronic substrate shown.
[0021] Figure 6 yes Figure 3 as well as Figure 4 A cross-sectional view of a through hole of a discharge pattern in an electronic substrate is shown.
[0022] Figure 7 It is used to determine Figure 3 as well as Figure 4 A diagram showing an experiment on the distance between circuit patterns in an electronic substrate.
[0023] Figure 8 Yes means Figure 7 The table of the first example of the experimental results is shown.
[0024] Fig. 9 Yes means Figure 7 The table of the second example of the experimental results is shown.
[0025] Explanation of symbols
[0026] 100: Electric motor
[0027] 101: Shell
[0028] 102: Cover
[0029] 103: Fan
[0030] 1: Electronic substrate
[0031] 1a: Surface
[0032] 1b: Back
[0033] 11: Opening
[0034] 12: Discharge pattern
[0035] 13: IC connection pattern
[0036] 14, 14a, 14b, 14c, 14d: IC
[0037] 15: Vcc
[0038] 16, 21: GND
[0039] 17, 17a, 17b, 17c: Capacitors
[0040] 18: Battery
[0041] 2: Connector
[0042] 3: Lead frame
[0043] 4: Rotor
[0044] 5: Axis
[0045] 6: Stator
[0046] 7: Ball bearing
[0047] 8: Ball bearings
[0048] 9: Wave washer
[0049] 20: Test circuit board
[0050] 22: Static electricity return path
[0051] 30: Discharge Gun
[0052] 31: Source of static electricity
[0053] 32: Electrostatic Discharge Department
[0054] 33: Static electricity return path
[0055] 34: Discharge current DETAILED DESCRIPTION
[0056] The motor 100 as an embodiment is described with reference to the accompanying drawings. The embodiments shown below are only examples and are not intended to exclude various modifications and technical applications not explicitly shown in the following embodiments. The various structures of this embodiment can be implemented in various modifications within the scope of their main purpose. In addition, selection can be made according to needs, or appropriate combinations can be made.
[0057] [1.Structure]
[0058] Figure 1is an exploded perspective view of the electric motor 100 according to the present embodiment. Figure 2 yes Figure 1 The schematic cross-sectional view of the motor 100 shown in FIG. The motor 100 of this embodiment is, for example, a small brushless motor used in office equipment, household electrical appliances, etc. In addition, the type and application of the motor 100 are not particularly limited. For example, the motor 100 may also be a brushed motor or a linear motor.
[0059] like Figure 1 as well as Figure 2 As shown, the motor 100 includes: an electronic substrate 1, a lead frame 3, a rotor 4, and a stator 6 built between a housing 101 and a cover 102; and a shaft 5 that rotates integrally with the rotor 4. The housing 101 is formed into a bottomed cylindrical shape, and a ball bearing 7 that rotatably supports one end of the shaft 5 is installed at the bottom. The cover 102 that fixes the ball bearing 8 is connected to the opening of the housing 101 via a wave washer 9. The shaft 5 passes through the opening 11 of the electronic substrate 1 (using Figure 3 as well as Figure 4 The electronic substrate 1 is connected to a connector 2 for connecting to an electronic device outside the motor 100 .
[0060] like Figure 2 As shown, the ball bearing 7 side of the shaft 5 extends to the outside of the housing 101 at both ends, and a fan 103 is installed near the front end of the shaft 5. The fan 103 is made of resin, for example, and generates static electricity by dust floating in the surrounding air. The static electricity generated by the fan 103 is easy to move to the metal shaft 5.
[0061] Figure 3 yes Figure 1 FIG. 1 shows a surface 1a of an electronic substrate 1. Figure 4 yes Figure 1 FIG. 1 is a diagram of the back side 1 b of the electronic substrate 1 shown.
[0062] like Figure 3 as well as Figure 4 As shown, the electronic substrate 1 is disk-shaped, and an opening 11 for allowing the shaft 5 to pass therethrough is formed at the center.
[0063] like Figure 3 as well as Figure 4 As shown, one or more (four in the example shown) discharge patterns 12 are formed around the opening 11. The discharge pattern 12 is, for example, a through-hole shape, and functions as a circuit pattern for discharging static electricity supplied from the fan 103 via the shaft 5. For details of the discharge pattern 12, see Figure 6 Then narrate.
[0064] like Figure 3 as well as Figure 4 As shown, one or more IC connection patterns 13 connected to one or more (four in the example shown) ICs 14 (also referred to as "ICs 14a to 14d") are formed on the outer side of the electronic substrate 1 in the radial direction closer to the discharge pattern 12. The IC connection pattern 13 is a circuit pattern for passing a current or a signal to the IC 14. In addition, in the example shown in the figure, a plurality of IC connection patterns 13 are connected to each IC 14, but only one IC connection pattern is marked with the symbol "13" on each of the surface 1a and the back surface 1b of the electronic substrate 1. In addition, the IC 14 can be various electronic components that are desired to be protected from damage caused by static electricity, and is not limited to integrated circuits.
[0065] like Figure 3 as well as Figure 4 As shown, a power line (Vcc) 15 and a ground line (GND) 16 are connected to the electronic substrate 1 .
[0066] like Figure 3 As shown, one or more (three in the example shown) capacitors 17 (also referred to as "capacitors 17a to 17c") may be provided on the electronic substrate 1. Static electricity may pass through the discharge pattern 12 from the axis, be bypassed by the capacitor 17, and be discharged from Vcc 15 or GND 16.
[0067] That is, the IC connection pattern 13 is an example of a first circuit pattern for connecting specific electronic components in the electronic substrate 1. In addition, the discharge pattern 12 is an example of a second circuit pattern, which is formed in the electronic substrate 1 at a position closer to a component of the motor 100 charged with static electricity than the distance between the IC connection pattern 13 and the component, and is used to discharge static electricity.
[0068] The component of the motor 100 charged with static electricity may be the shaft 5, which is provided in the motor 100 so as to penetrate the electronic substrate 1. In addition, the discharge pattern 12 may be formed on the electronic substrate 1 through a through hole, and a plurality of the discharge patterns 12 may be formed on the electronic substrate 1. Furthermore, the discharge pattern 12 may discharge static electricity to the Vcc 15 (in other words, the positive electrode) side or the GND 16 (in other words, the negative electrode) side of the power supply in the electronic substrate 1. In addition, in the electronic substrate 1, a capacitor 17 may be provided between the discharge pattern 12 and the Vcc 15 side or the GND 16 side of the power supply.
[0069] Figure 5 (a) to Figure 5 (d) is a circuit diagram of the present invention.
[0070] There are two types of discharge paths depending on whether the electrostatic discharge unit 32 is on the Vcc 15 side or the GND 16 side. The two paths are respectively connected to the negative side of the battery 18 or the positive side of the battery 18 by the electrostatic return path 33 through which the discharge current 34 flows. There are four paths in total. In addition, the electrostatic discharge unit 32 receives the electrostatic charge from the electrostatic generating source 31 (equivalent to Figure 1 as well as Figure 2 The axis 5) is shown as a direct discharge point on the electronic substrate 1.
[0071] Figure 5 (a) is a discharge path in which "the electrostatic discharge unit 32 is on the Vcc 15 side" and "the electrostatic return path 33 is on the negative side of the battery 18".
[0072] Figure 5 (b) is a discharge path in which "the electrostatic discharge unit 32 is on the Vcc 15 side" and "the electrostatic return path 33 is on the positive side of the battery 18".
[0073] Figure 5 (c) is a discharge path in which "the electrostatic discharge unit 32 is on the GND 16 side" and "the electrostatic return path 33 is on the negative side of the battery 18".
[0074] Figure 5 (d) is a discharge path in which "the electrostatic discharge unit 32 is on the GND 16 side" and "the electrostatic return path 33 is on the positive side of the battery".
[0075] Figure 6 yes Figure 3 as well as Figure 4 2 is a cross-sectional view of a through hole of a discharge pattern 12 in an electronic substrate 1 shown.
[0076] like Figure 6 As shown, in the discharge pattern 12, the pattern shown by reference numeral B1 (see the hatched area) is connected to Vcc 15 or GND 16, and a pattern is formed in the through-holes in the direction from reference numeral B1 to reference numeral B3 and in the direction from reference numeral B2 to reference numeral B4.
[0077] In addition, the shape of the discharge pattern 12 is not limited to the through-hole shape, and may be, for example, a lightning rod shape, or a conductive line pattern that connects two of the four discharge patterns 12. In these cases, the lightning rod and the conductive line pattern are connected to Vcc15 or GND16, and static electricity flowing into the lightning rod and the conductive line pattern is discharged to Vcc15 or GND16.
[0078] Figure 7 It is used to determine Figure 3 as well as Figure 4 FIG. 1 is a diagram showing an experiment on the distance between circuit patterns in the electronic substrate 1. FIG.
[0079] exist Figure 7 The test circuit board 20 shown in the figure forms circuit patterns #1, #2, and #3, and is connected to GND 21. A cable is connected between the discharge gun 30 and GND 21 as an electrostatic return path 22. Circuit pattern #1 corresponds to Figure 3 as well as Figure 4 The discharge pattern 12 shown in FIG. 1 is equivalent to the circuit pattern #2. Figure 3 as well as Figure 4 The axis 5 shown, circuit pattern #3 is equivalent to Figure 3 as well as Figure 4 The IC connection pattern 13 shown. The distance between circuit pattern #1 and circuit pattern #2 is a, and the distance between circuit pattern #2 and circuit pattern #3 is b. Here, the circuit pattern #2 is discharged by the discharge gun 30, thereby determining Figure 3 as well as Figure 4 The distance between circuit patterns in the electronic substrate 1 is shown.
[0080] Figure 8 Yes means Figure 7 The table of the first example of the experimental results is shown. Figure 8 In the example shown, the distance a between circuit pattern #1 and circuit pattern #2 is 0.585 mm, the distance b between circuit pattern #2 and circuit pattern #3 is 0.596 mm, and the difference between the distance a and the distance b is 0.011 mm.
[0081] The discharge gun 30 was used to discharge 100 times in pattern #2. In pattern #1, 9 discharges were made at +4 kV and 42 discharges were made at -4 kV, for a total of 51 discharges. In pattern #3, 39 discharges were made at +4 kV and 6 discharges were made at -4 kV, for a total of 45 discharges. Furthermore, in both patterns #1 and #3, 2 discharges were made at +4 kV and 2 discharges were made at -4 kV, for a total of 4 discharges.
[0082] As described above, if the difference between the distance a and the distance b approaches 0.011 mm, there is a possibility that static discharge may occur to the pattern #3 from which static discharge is desired to be prevented.
[0083] Fig. 9 Yes means Figure 7 The table of the results of the experiment shown in the second example. Fig. 9 In the example shown, the distance a between circuit pattern #1 and circuit pattern #2 is 0.676 mm, the distance b between circuit pattern #2 and circuit pattern #3 is 0.998 mm, and the difference between the distance a and the distance b is 0.322 mm.
[0084] The discharge gun 30 was used to discharge 200 times in pattern #2. In pattern #1, a current of +4 kV was discharged 100 times, a current of -4 kV was discharged 100 times, and a total of 200 discharges were observed. In addition, in pattern #3, a current of +4 kV was discharged 0 times, a current of -4 kV was discharged 0 times, and a total of 0 discharges were observed.
[0085] As described above, when the difference between the distance a and the distance b is 0.3 mm or more, preferably 0.322 mm or more, it is possible to prevent discharge to the pattern #3 from which it is desired to prevent static discharge.
[0086] [2. Effect]
[0087] (1) According to the above-mentioned motor 100, since the discharge pattern 12 is formed in the electronic substrate 1 at a position closer to the component of the motor 100 charged with static electricity than the distance between the IC connection pattern 13 and the component, it is possible to suppress the failure of electronic components or malfunction of electronic circuits caused by static electricity.
[0088] (2) In addition, since the member of the motor 100 that is charged with static electricity is the shaft 5 and is provided in the motor 100 so as to penetrate the electronic substrate 1, the size of the housing of the motor 100 can be reduced.
[0089] (3) Furthermore, since the discharge pattern 12 is formed on the electronic substrate 1 through the through hole, static electricity can be appropriately discharged even when discharge from the shaft 5 occurs to either the front surface 1 a or the back surface 1 b of the electronic substrate 1 .
[0090] (4) In addition, since a plurality of discharge patterns 12 are formed on the electronic substrate 1, even if there is a gap (in other words, play) between the shaft 5 and the opening 11 of the electronic substrate 1 due to assembly error or the shaft 5 vibrates within the opening 11 of the electronic substrate 1, the difference between the distance between the shaft 5 and the IC connection pattern 13 and the distance between the shaft 5 and the discharge pattern 12 can be appropriately maintained.
[0091] (5) In addition, since the discharge pattern 12 discharges static electricity to the positive electrode side or the negative electrode side of the power source in the electronic substrate 1 , the electronic components on the electronic substrate 1 can be appropriately protected.
[0092] (6) In addition, since the capacitor 17 is provided between the discharge pattern 12 and the positive or negative side of the power supply in the electronic substrate 1, the current discharged on the electronic substrate 1 can be made into a pulsed state (in other words, a high-frequency signal) and flow to the capacitor 17 with a small impedance. As a result, static electricity will not flow to electronic components such as IC 14, and by allowing static electricity to flow through the capacitor 17 reliably and quickly, the possibility of failure of electronic components can be further reduced.
[0093] (7) In addition, since the difference between the distance between the statically charged motor 100 member and the IC connection pattern 13 and the distance between the statically charged motor 100 member and the discharge pattern 12 is 0.3 mm or more, the electronic components on the electronic substrate 1 can be appropriately and reliably protected.
[0094] [3. Others]
[0095] The disclosed technology is not limited to the above-mentioned embodiments, and can be implemented in various modified forms within the scope of the gist of the embodiments. The structures and processes of the embodiments can be selected or omitted as needed, or can be appropriately combined.
Claims
1. An electric motor comprising a substrate, characterized in that: have: a first circuit pattern for connecting specific electronic components in the substrate; and a second circuit pattern formed in the substrate at a position closer to a member of the motor charged with static electricity than the first circuit pattern is to the member, and used to discharge the static electricity; The member is a shaft, which is provided on the motor so as to pass through the substrate.
2. The electric motor according to claim 1, characterized in that The second circuit pattern is formed on the substrate through a through hole.
3. The electric motor according to claim 1, characterized in that A plurality of the second circuit patterns are formed on the substrate.
4. The electric motor according to claim 1, characterized in that The second circuit pattern discharges the static electricity toward a positive electrode side or a negative electrode side of a power source in the substrate.
5. The electric motor according to claim 4, characterized in that The substrate includes a capacitor between the second circuit pattern and the positive electrode side or the negative electrode side.
6. The electric motor according to any one of claims 1 to 5, characterized in that: A difference between a distance between the member and the first circuit pattern and a distance between the member and the second circuit pattern is 0.3 mm or more.