Electric air pump

Abstract

An electric air pump, comprising a pump housing (10), a motor (20) disposed within the pump housing (10), an impeller (30) driven by the motor (20), and a controller (40) connected to the motor (20); the motor (20) is a DC brushless motor and includes a rotating shaft, and the impeller (30) is fixed to the rotating shaft; the pump housing (10) is successively provided with a first chamber (11), a second chamber (12), and a third chamber (13) along the axial direction of the motor (20), the first chamber (11) and the third chamber (13) are respectively located at the axial two ends of the second chamber (12), the controller (40) is received in the first chamber (11), the motor (20) is disposed in the second chamber (12), the impeller is disposed in the third chamber (13), the pump housing (10) is further provided with an air inlet portion (18) adjacent to the first chamber (11), an air outlet portion (19) adjacent to and communicating with the third chamber (13), and a flow passage (100) having two ends respectively communicating with the air inlet portion (18) and the third chamber (13). This electric air pump is driven by a brushless motor, has a fast response speed, a long service life, low noise, and high efficiency.

Description

Technical Field

[0001] The present invention relates to the field of electric technology, and particularly to an electric air pump. Background Art

[0002] Adding an OPF (gasoline particulate filter) to the exhaust emission system of an automobile can effectively reduce the emissions of harmful substances in the automobile exhaust. The OPF is usually provided with an electric air pump for delivering secondary air into the exhaust pipe to promote the oxidation of harmful substances in the exhaust gas discharged from the engine, which is beneficial to the further oxidation of CO or HC. However, the existing electric air pump is driven by a brushed motor and has a series of disadvantages, such as slow response speed, short service life, high noise, low efficiency, etc. Summary of the Invention

[0004] Technical Problem

[0005] In view of this, the present invention aims to provide an electric air pump that can solve or at least alleviate the above problems.

[0006] Solution to the Problem

[0007] Technical Solution

[0008] An electric air pump includes a pump housing, a motor disposed in the pump housing, an impeller driven by the motor, and a controller connected to the motor. The motor is a DC brushless motor. The motor includes a rotating shaft, and the impeller is fixed to the rotating shaft. The pump housing is sequentially provided with a first chamber, a second chamber, and a third chamber along the axial direction of the motor. The first chamber and the third chamber are respectively located at the axial two ends of the second chamber. The controller is received in the first chamber, the motor is disposed in the second chamber, and the impeller is disposed in the third chamber. The pump housing is further provided with an air inlet portion adjacent to the first chamber, an air outlet portion adjacent to and communicating with the third chamber, and a flow passage with two ends respectively communicating with the air inlet portion and the third chamber.

[0009] An electric air pump includes: a motor having a rotating shaft; a housing that extends in the axial direction of the rotating shaft and houses the motor; a first outer end cover and a second outer end cover respectively fixed at both ends of the housing; an impeller connected to the rotating shaft and disposed near the second outer end cover; and a controller received in the housing and near the first pump cover. The electric air pump is provided with a cooling channel for guiding cooling air flow to cool and dissipate heat from the electric air pump in the working state of the pump. The cooling channel includes an air inlet portion provided on the first outer end cover, a flow passage provided in the housing, and an air outlet portion provided on the second outer end cover.

[0010] Advantageous Effects of the Invention

[0011] Advantageous Effects

[0012] The electric air pump provided by the present invention is driven by a brushless motor, featuring a fast response speed, long service life, low noise, and high efficiency.

[0013] Brief Description of the Drawings Description of the Drawings

[0014] Figure 1 It is a three-dimensional assembly diagram of the electric air pump according to an embodiment of the present invention.

[0015] Figure 2 It is Figure 1 a cross-sectional view of the electric air pump shown.

[0016] Figure 3 It is Figure 1 an exploded view of the electric air pump shown.

[0017] Figure 4 It is Figure 1 another perspective view of the housing of the electric air pump shown.

[0018] Figure 5 It is Figure 4 a schematic cross-sectional view of the exhaust part of the housing shown.

[0019] Figure 6 It is Figure 1 another perspective view of the second outer end cover of the electric air pump shown.

[0020] Figure 7 It is Figure 1 a schematic structural view of the overheat protection element of the electric air pump shown.

[0021] Figure 8 It is Figure 1 an assembly diagram of the motor stator of the electric air pump shown.

[0022] Figure 9 It is Figure 8 an exploded view of the motor stator shown.

[0023] Figure 10 It is Figure 8 a bottom view of the motor stator shown.

[0024] Figure 11 It is Figure 8 a plan view of the iron core of the motor stator shown.

[0025] Figure 12 It is Figure 11 a partial plan exploded view of the stator iron core shown.

[0026] Figure 13 It is Figure 1 a schematic structural view of the connector of the electric air pump shown.

[0027] Figure 14 Yes Figure 13 is the assembly drawing of the connector and the housing shown.

[0028] Figure 15 Yes Figure 14 is the exploded view of.

[0029] Figure 16 is the three-dimensional schematic diagram of the motor rotor of the electric air pump shown in Figure 1.

[0030] Figure 17 Yes Figure 16 is the exploded view of the motor rotor shown.

[0031] Figure 18 Yes Figure 16 is the three-dimensional schematic diagram of the iron core of the motor rotor shown.

[0032] Figure 19 Yes Figure 18 is the top view of the rotor iron core shown.

[0033] Figure 20 Yes Figure 18 is the plan view of the iron core laminations of the rotor iron core shown.

[0034] Figure 21 Yes Figure 1 is the three-dimensional view of the magnetic induction part of the electric air pump shown.

[0035] Figure 22 Yes Figure 21 is the exploded view of.

[0036] Figure 23 Yes Figure 1 is the schematic diagram of the shock-absorbing mounting part of the electric air pump shown.

[0037] Figure 24 Yes Figure 23 is the exploded view of.

[0038] Figure 25 Three-dimensional schematic diagram of the second embodiment of the electric air pump of the present invention.

[0039] Figure 26 Three-dimensional schematic diagram of the third embodiment of the electric air pump of the present invention.

[0040] Figure 27 Three-dimensional schematic diagram of the fourth embodiment of the electric air pump of the present invention.

[0041] Figure 28 Three-dimensional schematic diagram of the fifth embodiment of the electric air pump of the present invention.

[0042] Embodiment of the invention

[0043] Embodiments of the present invention

[0044] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, so that the technical solutions and their beneficial effects of the present invention are clearer and more understandable. It can be understood that the accompanying drawings are only for reference and illustration, and are not used to limit the present invention. The dimensions shown in the drawings are only for clear description and do not limit the proportional relationship.

[0045] Referring also to Figures 1 to 3 , an electric air pump according to an embodiment of the present invention includes a pump housing 10, a motor 20 disposed in the pump housing 10, an impeller 30 driven by the motor 20, and a controller 40 connected to the motor 20. The motor 20 and the controller 40 together constitute a driving device of the electric air pump. A first chamber 11, a second chamber 12, and a third chamber 13 are formed in the pump housing 10. The first chamber 11, the second chamber 12, and the third chamber 13 are arranged in sequence along the axial direction of the motor 20. The first chamber 11 and the third chamber 13 are respectively located at the axial two ends of the second chamber 12. The controller 40 is disposed in the first chamber 11, the motor 20 is disposed in the second chamber 12, and the impeller 30 is disposed in the third chamber 13.

[0046] The pump housing 10 includes a housing 14, an inner end cover 15, a first outer end cover 16, and a second outer end cover 17. The housing 14 is generally in the shape of a hollow barrel. A boss 140 is formed on the inner wall surface of the housing 14 near its first end ( Figure 1 and 2 the top end in Figure 1 and 2 the bottom end in

[0047] A first opening 150 and a second opening 151 are formed at the center of the inner end cover 15, enabling the rotor 22 of the motor 20 to be pivotally connected to the inner end cover 15. The first opening 150 and the second opening 151 are arranged in axial sequence, and a flange 152 is formed on the inner wall surface of the inner end cover 15 between the first opening 150 and the second opening 151. A cap 153 is connected to the inner end cover 15 by fixing members such as screws to close the first opening 150 of the inner end cover 15. Preferably, a sealing ring 50 is provided between the cap 153 and the inner end cover 15 to ensure the tightness of their connection; an annular accommodation groove 154 is formed on the outer wall surface of the inner end cover 15, and a sealing ring 51 is arranged in the accommodation groove 154 to ensure the sealing between the inner end cover 15 and the inner wall surface of the housing 14, preventing dust, water vapor, etc. from entering the second chamber 12 and affecting the electrical safety of the motor 20.

[0048] The first outer end cover 16 is disposed at the top of the housing 14 and forms the enclosed first chamber 11 between the first outer end cover 16 and the inner end cover 15. In this embodiment, both the first outer end cover 16 and the housing 14 are formed with fixing holes, and fixing members such as screws pass through the corresponding fixing holes to fixedly connect the first outer end cover 16 to the top of the housing 14. Preferably, the first outer end cover 16 protrudes downward to form a ring edge 160, and an annular slot 142 is formed at the top of the housing 14. During assembly, the ring edge 160 is inserted into the slot 142, so that the interface between the first outer end cover 16 and the housing 14 is zigzag, effectively preventing external dust, water vapor, etc. from entering the first chamber 11 and affecting the electrical safety of the controller 40. Preferably, the first outer end cover 16 is made of a high thermal conductivity material such as cast aluminum, and thus has the function of a radiator. In this embodiment, the first outer end cover 16 is formed with several columnar protrusions and other features to increase the heat dissipation area and enhance the heat dissipation effect. The second outer end cover 17 is disposed at the bottom of the housing 14 and closes the bottom of the housing 14, and the third chamber 13 is formed between the second outer end cover 17 and the base 141. In this embodiment, both the second outer end cover 17 and the housing 14 are formed with fixing holes, and fixing members such as screws pass through the corresponding fixing holes to fixedly connect the second outer end cover 17 to the bottom of the housing 14. Preferably, a sealing ring 52 is provided between the second outer end cover 17 and the housing 14 to ensure the tightness of their connection and prevent air leakage due to poor sealing.

[0049] An air inlet portion 18 and an air outlet portion 19 are formed on the pump housing 10. A flow channel 100 is formed in the pump housing 10 to communicate the air inlet portion 18 with the third chamber 13. In this embodiment, the air inlet portion 18 is formed at the top of the pump housing 10 and the air outlet portion 19 is formed at the bottom of the pump housing 10, that is, the air inlet portion 18 and the air outlet portion 19 are respectively close to opposite ends of the motor 20. Specifically, the air inlet portion 18 is formed on the first outer end cover 16. The air inlet portion 18 is a hollow cylindrical portion extending axially parallel to the motor 20 and not coaxial with the motor 20. The air outlet portion 19 is formed on the side wall of the housing 14 near the second outer end cover 17. The air outlet portion 19 is a hollow cylinder extending tangentially along the outer periphery of the housing 14 and perpendicular to the air inlet portion 18. The air outlet portion 19 communicates the third chamber 13 with the outside. The flow channel 100 extends axially parallel to the motor 20 and is not coaxial with the motor 20. Preferably, the flow channel 100 is coaxial with the air inlet portion 18. In this embodiment, the cross-section of the flow channel 100 is generally D-shaped. During operation, air flow is introduced into the pump housing 10 from the air inlet portion 18, flows along the flow channel 100 and is then discharged from the pump housing 10 through the air outlet portion 19. In this embodiment, since the air inlet portion 18 and the air outlet portion 19 are respectively located at both ends of the pump housing 10, the air flow axially passes through the pump housing 10 and directly contacts the walls of the first chamber 11 and the second chamber 13, which can effectively dissipate heat from the motor 20 and the controller 40. That is, the air inlet portion 18, the flow channel 100 and the air outlet portion 19 together constitute a cooling channel. Preferably, the housing 14, the first outer end cover 16, and the second outer end cover 17 are made of high thermal conductivity materials, and the cooling channel is designed such that during operation, most (more than 50%) of the heat load from the controller can be dissipated to the cooling air flow through the pump housing. The high thermal conductivity material can be a metal material, such as cast aluminum, or a non-metal material, such as a synthetic material (plastic) added with high thermal conductivity non-metal material particles (such as carbon black particles) or metal particles (such as aluminum particles). Of course, the housing 14, the first outer end cover 16, and the second outer end cover 17 can be made of different materials. For example, the housing 14 can be made of cast aluminum, and the first outer end cover 16 can be made of a synthetic material with a lower thermal conductivity than the housing 14.

[0050] It should be noted that in order to ensure the normal operation of the motor 20 and the controller 40, the flow channel 100 is not communicated with the first and second chambers 11, 13, that is, the generated air flow does not flow into the first and second chambers 11, 13 and directly contact the motor 20 and the controller 40.

[0051] Such as Figures 4 - 5As shown, a first channel 101 is formed by the depression on one side of the base 141 of the housing 14 facing the second outer end cap 17. The first channel 101 is generally C-shaped and extends around the central axis of the housing 14. In this embodiment, the peripheral edge on the radially outer side of the first channel 101 is located at the connection between the inner side wall surface of the housing 14 and the base 141. One end of the first channel 101 is connected to the exhaust portion 19 through an outlet section 102, and the other end extends to communicate with the flow channel 100. The end of the first channel 101 connected to the flow channel 100 is the air inlet of the third chamber 13. In this embodiment, the outlet section extends linearly, but the cross-sectional area of the outlet section 102 is smaller than that of the first channel 101, thereby accelerating the air flow.

[0052] As Figure 6 shown, a second channel 106 is formed by the depression on one side of the second outer end cap 17 facing the base 141. The second channel 106 corresponds to the first channel 101 in position. Similarly, the second channel 106 extends generally C-shaped around the center of the second outer end cap 17; the cross-section of the second channel 106 is generally D-shaped. One end of the second channel 106 is communicated with the air inlet of the third chamber 13, and the other end extends to an inclined surface 107, and the inclined surface 107 is opposite to the position of the exhaust portion 19.

[0053] The inner cavity cross-section of the exhaust portion 19 perpendicular to the air flow direction is non-circular and is enclosed by a first inner edge 191, a second inner edge 192, and a third inner edge 193 that are connected end to end in the circumferential direction. The first inner edge 191 and the second inner edge 192 are generally V-shaped, and the V-shaped opening faces the radially outer side of the housing 14. The first inner edge 191 forms a first angle α with the rotation axis O-O of the impeller 30, and the range of the first angle α is 0 to 90°. The second inner edge 192 forms a second angle β with the rotation axis O-O of the impeller 30, and the range of the second angle β is 0 to 90°. Preferably, the first angle α is 45°, the second angle β is 45°, and the angle between the first inner edge 191 and the second inner edge 192 is 90°. The third inner edge 193 is an arc segment connecting the first inner edge 191 and the second inner edge 192, and the center of the arc segment 193 deviates from the intersection of the first inner edge 191 and the second inner edge 192.

[0054] Furthermore, a convex portion 103 is protrudingly provided on the inner wall surface of the housing 14. The convex portion 103 is located between the two ends of the first channel 101. First inclined portions 104 and second inclined portions 105 are respectively formed on both circumferential sides of the convex portion 103. The first inclined portion 104 is adjacent to the flow channel 100 and is located upstream of the air flow inlet of the third chamber 13, and the second inclined portion 1051 is adjacent to the exhaust portion 19 and is located downstream of the exhaust portion 19. The first inclined portion 104 and the second inclined portion 105 are both inclined with respect to the rotation axis O-O of the impeller 30 and have opposite inclined directions. The ends of the first inclined portion 104 and the second inclined portion 105 facing the second outer end cover 17 are close to each other, and the ends facing the base 141 are far from each other, thereby reducing the pressure pulsation caused by the air flow, and thus improving the pneumatic audio noise.

[0055] The impeller 30 is rotatably provided in the third chamber 13. The diameter of the impeller 30 is smaller than the inner diameter of the housing 14, so that a gap is formed between the impeller 30 and the housing 14. The gap communicates with the first channel 101 and the first channel 101. Under the action of the impeller 30, external air flow enters the pump housing 10 from the air inlet portion 18, flows through the first chamber 11 and the second chamber 12 along the flow channel 100 and then enters the third chamber 13, and finally flows out of the pump housing 10 from the exhaust portion 19. The exhaust portion 19 of the electric air pump of the present invention forms a non-circular inner cavity cross-section, and a first inclined portion 104 is formed upstream of the air flow inlet and a second inclined portion 105 is formed downstream of the exhaust portion 19, reducing the pressure pulsation caused by the air flow, thereby effectively reducing the noise. In addition, during the flow of the air flow in the pump housing 10, it flows through the second chamber 12 and takes away the heat generated by the motor 20 in the second chamber 12, which has a heat dissipation effect on the motor 20, ensuring that the working temperatures of the controller 40 and the motor 20 are within an appropriate range, ensuring electrical safety and extending the service life.

[0056] As Figure 3 shown, the motor 20 is a direct current brushless motor, including a stator 21 and a rotor 22 that rotates relative to the stator 21. The motor 20 is an inner rotor motor, and the stator 21 is disposed around the rotor 22. The impeller 30 is fixedly connected to the rotor 22 and rotates synchronously with the rotor 22. The controller 40 is electrically connected to the motor stator 21 to control the rotation of the motor 20.

[0057] As Figure 2, as shown in FIGS. 3 and 7, the controller 40 is fixedly connected to the housing 14 by screws or the like, and includes a circuit board 49 and a plurality of electronic devices disposed on the circuit board 49. The inner end cover 15 is a cast aluminum part with high thermal conductivity, and acts as a radiator to dissipate heat from the circuit board 49. Preferably, the controller 40 further includes an overheat protection element 41 connected to the circuit board 49. When the temperature is too high, the overheat protection element 41 fuses to form a power-off protection for the motor 20. Specifically, the overheat protection element 41 includes a first terminal 42, a second terminal 43, and a spring piece 44 integrally extended from the first terminal 42. The first terminal 42 and the second terminal 43 are inserted into the circuit board 49 and connected to the corresponding positive and negative contacts on the circuit board 49, that is, the first terminal 42 and the second terminal 43 are connected in series in the power supply circuit of the circuit board 49. The extending direction of the spring piece 44 deviates from the connection line of the first terminal 42 and the second terminal 43 by a certain angle when not under force, so that the end of the spring piece 44 deviates from the second terminal 43 by a small distance when not under force. During assembly, the end of the spring piece 44 is electrically connected and mechanically fixed to the second terminal 43 by soldering, and at this time the spring piece 44 is elastically deformed.

[0058] Preferably, the first terminal 42 and the second terminal 43 are assembled into one body by a frame 45. The frame 45 is in an inverted "U" shape and includes a first cross bar 46 and a second cross bar 47 arranged in parallel up and down, and a connecting rod 48 connecting the first cross bar 46 and the second cross bar 47. The tops of the first terminal 42 and the second terminal 43 are respectively inserted and fixed in the first cross bar 46, and the bottoms of the first terminal 42 and the second terminal 43 are fixed to the second cross bar 47 and pass through the second cross bar 47 and then are connected to the circuit board 49. In this way, the relative positions of the first terminal 42 and the second terminal 43 and the alignment connection with the circuit board 49 are ensured, and the connection stability between the first terminal 42, the second terminal 43 and the circuit board 49 is ensured. In this embodiment, the first terminal 42 is arranged close to the connecting rod 48, and the second terminal 43 is arranged close to the opening side of the frame 45, which is convenient for the spring piece 44 to be fixed to the second terminal 43 by brazing. The spring piece 44 is located between the first cross bar 46 and the second cross bar 47. When the spring piece 44 is welded to the second terminal 43, it is substantially parallel to the first cross bar 46 and the second cross bar 47. On the contrary, the spring piece 44 forms an angle with the first cross bar 46 and the second cross bar 47 when not under force.

[0059] Please also refer to Figures 8 - 12, the motor stator 21 includes a stator core 210 and a coil 211 wound around the stator core 210. The stator core 210 is formed by splicing a plurality of stator core segments 212. In this embodiment, there are 6 stator core segments 212, and each stator core segment 212 serves as a magnetic pole of the stator 21. Each stator core segment 212 is formed by stacking a number of iron core laminations, and includes an inner arc portion 213, an outer arc portion 214, and a tooth body 215 connecting the inner arc portion 213 and the outer arc portion 214. The inner arc portions 213 of the respective stator core segments 212 together form the inner circle of the stator core 210, and the outer arc portions 214 together form the outer circle of the stator core 210. The coil 211 is wound around the tooth body 215. Preferably, an insulating bracket 216 is installed at the axial end of each stator core segment 212, and the insulating bracket 216 isolates the coil 211 to avoid short circuit. Since the stator core 210 is composed of multiple segments spliced together, each stator core segment 212 can be wound independently first, so that the winding is not affected by adjacent stator core segments 212, ensuring the slot fill factor of the winding and improving the efficiency of the motor 20.

[0060] At the circumferential two ends of the outer arc portion 214 of each stator core segment 212 of the stator core 210, a convex block 218 and a groove 219 are respectively formed. The convex block 218 and the groove 219 are similar in shape and size, and are both approximately semicircular in this embodiment. During assembly, the convex block 218 of each stator core segment 212 is inserted into the groove 219 of an adjacent stator core segment 212, and correspondingly, its groove 219 is inserted into the convex block 218 of another adjacent stator core segment 212. In this way, the respective stator core segments 212 are connected into a circular structure through the engagement of the convex block 218 and the groove 219. In addition, at the circumferential two ends of the outer peripheral surface of the outer arc portion 214 of each stator core segment 212, a depression 2140 is formed by inward concavity respectively. At the circumferential outer end of the depression 2140, a tiny protrusion 2141 is formed. After the respective stator core segments 212 are connected into a whole through the convex block 218 and the groove 219, the two protrusions 2141 at the adjacent ends of the adjacent two stator core segments 212 approach each other and are connected by welding to ensure the stability of the connection of the respective stator core segments 212 and avoid the connection between the groove 219 and the convex block 218 from becoming unstable or even disengaging due to wear and other reasons. Preferably, the protrusion 2141 does not protrude beyond the outer peripheral surface of the stator core segment 212 in the radial direction and does not affect the overall shape of the stator 21 after welding.

[0061] A connection seat 217 is provided on the stator coil 211. The connection seat 27 is formed with pins 2170. The coil 211 is electrically connected through the connection seat 217 and the pins 2170, and the pins 2170 are connected to the controller 40 through a connector 23.

[0062] As Figures 13 - 15As shown, the connector 23 includes a terminal sleeve 230 and a plurality of terminals 231 fixed within the terminal sleeve 230. In this embodiment, the terminal sleeve 230 is connected to the outer wall of the housing 14 corresponding to the first chamber 11 by fixing members such as screws. An opening 149 is formed on the outer wall of the housing 14, and an annular groove 148 is formed around the opening 149. The terminal sleeve 230 includes an abutting end that abuts against the housing and a plugging end for plugging in a corresponding external connector. An annular rib 232 is formed on the abutting end of the terminal sleeve. The rib 232 is inserted into the annular groove 148. Preferably, there is potting glue, such as Dowsil 9176, etc., in the annular groove 148 to seal and connect the terminal sleeve 230 and the housing 14. Since the rib 232 is inserted into the annular groove 148, the contact area between the housing 14 and the terminal sleeve 230 is increased, and the bonding between the two is more firm, effectively increasing the potting glue coverage area, ensuring the tightness and stability of the connection, and preventing external moisture, dust, etc. from entering the first chamber 11 and affecting the electrical safety of the controller 40.

[0063] Another annular rib 233 is formed in the enclosed area of the rib 232 at the abutting end of the terminal sleeve 230. The terminals 231 are arranged in the enclosed area of the rib 233 and are aligned with the opening 149 on the side wall. Preferably, the terminals 231 are fixed to the terminal sleeve 230 by insert molding, and then potting glue is filled in the enclosed area of the rib 233 to ensure the stability of the connection of the terminals 231 and the seal between the terminals 231 and the terminal sleeve 230. One end of the terminal 231 facing the housing 14 is connected to the controller 40, and the other end is used to connect an external power source and a control signal source. In this embodiment, the terminal 231 is connected to the controller 40 through the overheat protection element 41, that is, two of the terminals 231 connecting to the external power source are respectively connected to the first terminal 42 and the second terminal 43 of the overheat protection element 41. Under normal conditions, the elastic piece 44 is welded to the second terminal 43 to conduct the motor 20 with the external power source. The controller 40 periodically changes the current of the stator coil 211 as needed, thereby generating a changing magnetic field that interacts with the magnetic field of the rotor 22 to drive the rotor 22 to rotate continuously.

[0064] When an abnormality occurs in the electric air pump of the present invention, such as internal overheating, the temperature usually exceeds the melting point of the solder joint between the elastic piece 44 and the second terminal 43 (such as 220 °C). At this time, the elastic piece 44 and the second terminal 43 are fused, and the elastic piece 44 returns to its original shape under the action of its own elastic restoring force and deviates from the second terminal 43, so that the motor 20 is disconnected from the external power source. In this way, when an overheating or other situation occurs inside the electric air pump of the present invention, the power can be cut off in a timely and automatic manner, enhancing safety.

[0065] Such as Figures 16 - 17As shown, the rotor 22 is rotatably disposed in the inner ring of the stator 21, and includes a rotating shaft 220, a rotor core 221 fixedly sleeved on the rotating shaft 220, and a permanent magnet 222 inserted into the rotor core 221.

[0066] Please also refer to Figure 2 , the rotating shaft 220 is a longitudinally long rod, and the bottom end of the rotating shaft 220 passes through the base 141 and extends into the third chamber 13. The impeller 30 is fixedly sleeved on the bottom end of the rotating shaft 220 and rotates synchronously with the rotating shaft 220. A bearing hole is formed in the base 141, and a first bearing 24 is disposed in the bearing hole. The bottom end of the rotating shaft 220 passes through the first bearing 24. Preferably, the first bearing 24 is a ball bearing. The top end of the rotating shaft 220 passes through the first opening 150 and the second opening 151 of the inner end cover 15. A second bearing 25 is disposed in the second opening 151. Preferably, the second bearing 25 is a ball bearing. The first bearing 24 and the second bearing 25 are respectively disposed at both ends of the rotating shaft 220 to support the rotation of the rotor 22, making its rotation smoother, with less noise.

[0067] Please also refer to Figure 2 , Figure 22 and Figure 23, a magnetic induction element 26 is disposed in the first opening 150. The magnetic induction element 26 is fixedly sleeved on the top end of the rotating shaft 220 and rotates synchronously with the rotor 22. Since the motor 20 is a brushless motor, the magnetic induction element 26 is used to detect the rotation position of the motor rotor, so that the controller 40 can quickly start the motor according to the rotor position. The magnetic induction element 26 includes a magnetic ring 260, a protective cover 261 sleeved on the magnetic ring 260, and a connecting member 262. The magnetic ring 260 is made of a polymer material mixed with magnetic powder by injection molding. The magnetic ring 260 has an annular structure, and a connecting hole 263 is formed in the center of the magnetic ring 260. The connecting member 262 is inserted into the connecting hole 263 and fixedly connected to the magnetic ring 260. In this embodiment, the connecting member 26 is fixedly integrated with the magnetic ring 260 by insert molding. A waist-shaped mounting hole 264 is formed in the center of the connecting member 262. The top end of the rotating shaft 220 is machined, and the cross section is waist-shaped, which matches the mounting hole 264 of the connecting member 262 of the magnetic ring 260. During assembly, the top end of the rotating shaft 220 is inserted into the mounting hole 264 of the connecting member 262, and the two are limited in the circumferential direction and cannot rotate relative to each other. The protective cover 261 is made of a high-strength, high-toughness and non-magnetic conductive material, such as stainless steel, copper, nylon, etc. The shape of the protective cover 261 matches that of the magnetic ring 260 and its strength is greater than that of the magnetic ring 260, so as to protect the magnetic ring 260 and prevent it from being damaged during high-speed rotation. In this embodiment, the protective cover 261 and the magnetic ring 260 are fixed by gluing. In other embodiments, the magnetic ring 260 and the protective cover 261 can also be fixed by other methods, such as tight fit, etc.

[0068] In this embodiment, as Figures 18 - 20 shown, the rotor core 221 is composed of two sub-cores 221a and 221b. The two sub-cores 221a and 221b have the same structure. Each sub-core 221a or 221b is formed by stacking a plurality of core laminations. The two sub-cores 221a and 221b are sequentially sleeved on the rotating shaft 220. The two rotor cores 221 are coaxially arranged in the axial direction but are relatively deflected in the circumferential direction. In this embodiment, the two sub-cores 221a and 221b are relatively deflected by about 11.25° in the circumferential direction, effectively reducing the cogging torque and torque ripple, and reducing the noise of the electric air pump of the present invention.

[0069] Circumferentially along the rotor 22, each sub-core 221a or 221b includes a plurality of concave portions 223 and convex portions 224 arranged at intervals. In this embodiment, there are 4 concave portions 223 and 4 convex portions 224. Each convex portion 224 serves as a magnetic pole of the rotor 22. Since the number of convex portions 224 of the rotor core 221 is different from the number of stator core segments 212, dead points can be avoided to ensure that the rotor 22 can start smoothly. The convex portion 224 is an outwardly convex arc, and the concave portion 223 is an inwardly concave arc. The length of the convex portion 224 in the circumferential direction is much greater than the length of the concave portion 223. The center of the convex portion 224 deviates from the center of the rotor core 221, so that the distance between the outer edge of the convex portion 224 and the rotor core 221 is variable. Thus, after the rotor 22 is assembled with the stator 21, the distance between the inner ring of the stator 21 and the outer edge of the rotor core 221 is variable, and a non-uniform air gap is formed between the stator 21 and the rotor 22, thereby improving the back electromotive force waveform to make it close to a sine wave and further reducing the vibration and noise of the electric air pump of the present invention.

[0070] A perforation 225 is formed on each sub-core 221a or 221b for installing a permanent magnet 222. In this embodiment, correspondingly, the number of the magnets is 4. A perforation 225 is formed on each convex portion 224 of the sub-core 221a or 221b. Two adjacent perforations 225 are perpendicular to each other, and the four perforations 225 are arranged in a square. Both ends of each perforation 225 are close to the position of the concave portion 223 of the rotor core 221 but do not penetrate the concave portion 223. The rotor core 221 has a minimum thickness dimension W at the end position corresponding to the perforation 225. Preferably, W is 0.5 mm to reduce magnetic leakage and improve the efficiency of the motor 20. The 4 magnets are respectively inserted into the 4 perforations 225 of the rotor core 221. In this embodiment, a partition 226 is provided at the outer end of each rotor core 221. The partition 226 forms a limit for the magnets in the axial direction to prevent the magnets from falling off during the high-speed rotation and vibration of the rotor 22. In this embodiment, the partitions 226 are all fixedly sleeved on the rotating shaft 220. By adjusting the structures and weights of the two partitions 226, the balance of the rotor 22 can be ensured and the noise can be reduced.

[0071] As Figure 1 , Figure 23 and Figure 24As shown, a bracket 60 is further connected to the pump housing 10 of the electric air pump of the present invention. The bracket 60 is used to connect the electric air pump of the present invention to other mechanisms of the vehicle. A plurality of shock-absorbing mounting members 70 are provided between the bracket 60 and the pump housing 10. The shock-absorbing mounting members 70 include an elastomer 71 and a first screw 72 and a second screw 73 respectively connected to both ends of the elastomer 71. The elastomer 71 can be made of materials such as rubber. Ring sleeves 74 are respectively formed at both ends of the elastomer 71, and the ring sleeves 74 are tightly sleeved on the heads of the first screw 72 and the second screw 73. The screw rod of the first screw 72 is screwed and fixed to the housing 14, and the screw rod of the second screw 73 is screwed and fixed to the bracket 60. The vibration of the electric air pump is buffered by the elastic member and basically will not continue to be transmitted outward to the bracket 60 and other mechanisms connected to the bracket 60. In this way, the vibration of the electric air pump is blocked from being transmitted outward through the shock-absorbing mounting members 70, and the influence on other components is reduced as much as possible.

[0072] According to the specific application environment of the electric air pump of the present invention, such as Figures 25 - 27 As shown, the bracket 60 can have different structures, among which Figure 25 The structure of the bracket 60 shown is the same as that of Figure 1 The bracket 60 is sleeved on the housing 14 and is connected to the outer wall surface of the housing 14 through the shock-absorbing mounting members 70; Figure 26 In the shown embodiment, the bracket 60 is sleeved around the housing 14 and forms a heat insulation baffle on one side of the housing 14 to reduce the influence of the heat generated by the engine on the normal operation of the electric air pump. A shock-absorbing mounting member 70 is provided between the bracket 60 and the housing 14; Figure 27 In the shown embodiment, the bracket 60 is semi-sleeved on the housing 14, and a shock-absorbing mounting member 70 is provided between the bracket 60 and the housing 14. Similarly, according to the specific application environment of the electric air pump of the present invention, the connector 23 of the electric air pump of the present invention can have different installation methods. Figure 1 As shown in Figure 28 In the embodiment, the outer end of the connector 23 faces downward; Figure 25 As shown in Figure 26 In the embodiment, the outer end of the connector 23 is arranged upward, while Figure 27 In the embodiment shown, the outer end of the connector 23 is inclined downward. Through different bracket structures, different installation spaces can be adapted. At the same time, the connector is installed at different angles according to the installation environment, which is convenient for connecting with other electronic devices.

[0073] The above are only the preferred specific embodiments of the present invention. The protection scope of the present invention is not limited to the above-listed embodiments. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by those skilled in the art within the technical scope disclosed by the present invention all fall within the protection scope of the present invention.

Claims

1. An electric air pump for pumping gas, comprising a pump housing, a motor disposed within the pump housing, an impeller driven by the motor, and a controller connected to the motor. The motor is a DC brushless motor and includes a rotating shaft. The impeller is fixed to the rotating shaft. The pump housing is sequentially provided with a first chamber, a second chamber, and a third chamber along the axial direction of the motor. The first chamber and the third chamber are respectively located at the axial two ends of the second chamber. The controller is received in the first chamber, the motor is disposed in the second chamber, and the impeller is disposed in the third chamber. The pump housing further has an air inlet portion adjacent to the first chamber, an air outlet portion adjacent to and communicating with the third chamber, and a flow passage with two ends respectively communicating with the air inlet portion and the third chamber. Under the action of the impeller, the pumped gas enters the pump housing from the air inlet portion, sequentially flows through the first chamber and the second chamber along the flow passage, and then enters the third chamber and is discharged from the pump housing through the air outlet portion. The flow passage is not communicated with the first and second chambers.

2. The electric air pump according to claim 1, wherein: The pump housing includes a cylindrical housing with two open ends, and a first outer end cover and a second outer end cover respectively covering the two ends of the housing. The air inlet portion is formed on the first outer end cover, and the air outlet portion is formed on the side wall of the housing near the second outer end cover.

3. The electric air pump according to claim 2, characterized in that: The air inlet portion is a hollow cylindrical portion extending parallel to the axial direction of the motor but deviating from the rotation axis of the motor.

4. The electric air pump according to claim 2, characterized in that: The air outlet portion is a hollow cylindrical body extending tangentially along the outer circumference of the housing.

5. The electric air pump according to claim 3, characterized in that: The flow passage extends parallel to the axial direction of the motor and is not coaxial with the motor.

6. The electric air pump according to claim 5, wherein: The flow passage is coaxial with the air inlet portion.

7. The electric air pump according to claim 5 or 6, characterized in that: The cross-section of the flow passage is generally in a D shape.

8. The electric air pump according to claim 2, wherein: The pump housing further includes an inner end cover fixed to the housing. A base is formed on the inner wall surface of the housing near the second outer end cover. The first chamber is formed between the inner end cover and the first outer end cover, the second chamber is formed between the base and the inner end cover, and the third chamber is formed between the second outer end cover and the base.

9. The electric air pump according to claim 8, characterized in that: The inner end cover and the housing are connected by welding.

10. The electric air pump according to claim 8, characterized in that: The inner end cover is provided with an opening for the motor to rotate therein. The electric air pump further includes a cap, which is fixed on the side of the inner end cover facing the first chamber and closes the opening of the inner end cover.

11. The electric air pump according to claim 10, wherein: A sealing ring is provided between the cap and the inner end cover.

12. The electric air pump according to claim 2, wherein: The first outer end cover is made of cast aluminum.

13. The electric air pump according to claim 2, characterized in that: An annular slot is formed at the end of the side wall of the housing near the first outer end cover. A ring edge is convexly provided on the outer edge of the first outer end cover, and the ring edge is inserted into the slot.

14. An electric air pump for pumping gas, comprising: A motor having a rotating shaft; A housing extending in the axial direction of the rotating shaft and receiving the motor; A first outer end cover and a second outer end cover respectively fixed to the two ends of the housing; An impeller connected to the rotating shaft and arranged near the second outer end cover; and A controller received in the housing and near the first pump cover; The housing is axially provided with a first chamber, a second chamber and a third chamber in sequence, which respectively accommodate the controller, the motor and the impeller. The electric air pump is provided with a cooling channel for guiding the pumped gas to cool and dissipate heat from the electric air pump in the working state of the pump. The cooling channel includes an air inlet part provided on the first outer end cover, a flow channel provided in the housing, and an air outlet part provided on the second outer end cover. Under the action of the impeller, the pumped gas enters the motor pump housing from the air inlet part, flows through the first chamber and the second chamber in sequence along the flow channel, and then enters the third chamber and is discharged from the pump housing through the air outlet part. The flow channel is not communicated with the first and second chambers.

15. The electric air pump according to claim 14, wherein: The cooling air flow flows through the cooling channel to cool the controller first and then the motor.

16. The electric air pump according to claim 14, characterized in that: The housing, the first outer end cover and the second outer end cover are made of high thermal conductivity materials, and the cooling channel is designed such that during operation, more than 50% of the heat load from the controller can be dissipated into the cooling air flow through the pump housing.

17. The electric air pump according to claim 16, wherein: The first outer end cover is made of a composite material with a thermal conductivity lower than that of the housing.

18. The electric air pump according to claim 17, wherein: The housing is made of metal.

19. The electric air pump according to claim 18, wherein: The housing is made of aluminum.

20. The electric air pump according to claim 14, characterized in that: The air outlet part guides the air flow to be discharged along the tangent direction of the impeller.

21. The electric air pump according to claim 14, characterized in that: The air outlet part guides the air flow to be discharged from the third chamber along the tangent direction of the impeller.

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