Low noise electronic vacuum pump

Abstract

The application provides a low-noise electronic vacuum pump, which comprises a motor, a stator, an impeller, a sound-absorbing assembly and an upper cover, a gas storage cavity and an air inlet are arranged on the motor flange, the stator is fixedly installed on the motor flange, the impeller is fixedly installed on the motor shaft and located in the cavity of the stator, the upper cover is fixedly installed on the upper end surface of the stator, and the sound-absorbing assembly is installed in the upper cover; the impeller comprises a hub and a plurality of blades fixed on the hub, and the outer side end of the plurality of blades is matched with the inner wall of the stator in a small gap. The vacuum pump provided by the application can reduce the heat and noise caused by friction, solve the problem of jamming after the length of the blade wear is shortened, has low requirement on the power of the motor, low temperature rise and good reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the brake system of electric vehicle, specifically relates to a low noise electronic vacuum pump. BACKGROUND

[0002] The electronic vacuum pump is the main part of the brake assist system of vehicle, which is very important for the safety of vehicle driving. The traditional electronic vacuum pump contains graphite rotor, vane and stator, which needs to adjust the gap between the stator and the rotor during assembly, and the vane and the stator are directly rubbed, which will generate a large amount of heat, causing serious heating, affecting the service life of the motor and the product pumping performance, and the long-term direct friction will shorten the length of the vane, and when the length of the vane is less than a certain percentage, the vane will be stuck in the rotor, causing the product to fail. In addition, the electronic vacuum pump compresses the gas, and when the high-pressure gas is discharged outward, it will produce a lot of noise, thereby affecting the NVH value of the whole vehicle (the NVH value is the index value of the comfort of all vehicle assembly plants). SUMMARY

[0003] The technical problem to be solved by the present application is to provide a low noise electronic vacuum pump capable of reducing noise.

[0004] To solve the above technical problems, the technical scheme of the present application is: a low noise electronic vacuum pump, comprising a motor, a stator, an impeller, a sound absorbing assembly and an upper cover, a gas storage cavity and an air inlet are arranged on the motor flange, the stator is fixedly installed on the motor flange, the impeller is fixedly installed on the motor shaft and located in the cavity of the stator, the upper cover is fixedly installed on the upper end surface of the stator, and the sound absorbing assembly is installed in the upper cover; the impeller comprises a hub and a plurality of vanes fixed on the hub, and the outer side end of the plurality of vanes is matched with the inner wall of the stator with a small gap.

[0005] In the above technical scheme, a gas storage cavity is added on the motor flange, the gas enters the gas storage cavity in the motor flange through the air inlet, and then the impeller replaces the traditional rotor and vane, which is installed on the motor shaft and can be fastened by a nut, so that the assembly is convenient and the gap does not need to be adjusted. The impeller comprises a hub and a plurality of vanes fixed on the hub, and the outer side end of the vane is matched with the inner wall of the stator with a small gap, which avoids direct friction between the two, thereby reducing the heat and noise caused by friction, and solving the problem of jamming after the length of the vane is shortened. The motor power requirement is low, the temperature rise is low, and the reliability is good.

[0006] In one embodiment, a gas expansion cavity is formed between the impeller and the upper cover.

[0007] In one embodiment, both the top cover and the silencing assembly are inverted pot-shaped structures. The top cover covers the silencing assembly, the top of the silencing assembly has an exhaust port, and the lower part of the top cover has multiple air outlets. Because both the top cover and the silencing assembly are inverted pot-shaped structures, this allows for more comprehensive coverage and silencing of the gas expansion chamber.

[0008] In one embodiment, the noise reduction assembly includes a pot-shaped expansion ring and multiple pieces of noise-reducing cotton attached to the outer arc surface of the expansion ring. Multiple limiting ribs on the outer arc surface of the expansion ring separate the pieces of noise-reducing cotton. A downwardly extending columnar body is provided at the top of the expansion ring, with an axial through-hole serving as an exhaust port. Both the expansion ring and the upper cover have annular bosses at their lower ends for mounting to the upper surface of the stator. Since the expansion ring and the upper cover cover the impeller, and the expansion ring only has one exhaust port at its top, the high-pressure gas expelled when the impeller rotates expands the expansion ring. This expansion ring then exerts pressure on the noise-reducing cotton, forcing it to adhere tightly to the inner wall of the upper cover. This ensures that the high-pressure gas can only be discharged through the exhaust port – noise-reducing cotton – air outlet sequentially. Furthermore, since the noise-reducing cotton is compressed, it can better absorb noise, thereby reducing the noise during vacuum pump exhaust.

[0009] In one embodiment, the lower surface of the annular boss of the expansion ring is further provided with a downwardly protruding sealing ring, and the upper end face of the stator is provided with a sealing groove corresponding to the sealing ring.

[0010] In one embodiment, the top cover is made of aluminum.

[0011] In one embodiment, the air inlet is equipped with a one-way valve. Attached Figure Description

[0012] Figure 1 This is a schematic cross-sectional view of the vacuum pump in an embodiment of the present invention;

[0013] Figure 2 This is a schematic diagram of the explosion structure of the vacuum pump in an embodiment of the present invention;

[0014] Figure 3 This is a top view of the impeller structure in an embodiment of the present invention;

[0015] Figure 4 This is a schematic cross-sectional view of the expansion ring in an embodiment of the present invention;

[0016] Figure 5 This is a schematic diagram of the stator upper end face structure in an embodiment of the present invention;

[0017] The attached diagram is labeled as follows: 1. Motor, 2. Stator, 2a. Sealing groove, 3. Impeller, 4. Top cover, 4a. Air outlet, 5. Air storage chamber, 6. One-way valve, 7. Gas expansion chamber, 8. Expansion ring, 8a. Limiting rib, 8b. Columnar body, 8c. Exhaust hole, 8d. Sealing ring, 9. Noise-absorbing cotton, 10. Nut. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] like Figures 1 to 5 As shown, a preferred embodiment of the present invention is: a low-noise electronic vacuum pump, including a motor 1, a stator 2, an impeller 3, a silencing assembly, and a top cover 4. The motor flange is provided with a gas storage chamber 5 and an air inlet, and a one-way valve 6 is installed in the air inlet. The stator 2 is fixedly installed on the motor flange. The impeller 3 is fixedly installed on the motor shaft through a flat square connection and is located in the cavity of the stator 2. The top cover 4 is fixedly installed on the upper end face of the stator 2. The silencing assembly is installed inside the top cover. The impeller 3 includes a hub and multiple blades fixed on the hub. The outer ends of the multiple blades are fitted with the inner wall of the stator 2 with a small clearance, forming a gas expansion chamber 7 between the impeller 2 and the top cover 4. The top cover 4 and the silencing assembly are both inverted pot-shaped structures. The top cover 4 covers the silencing assembly. The top of the silencing assembly is provided with an exhaust hole 8c, and the lower part of the top cover 4 is provided with multiple exhaust holes 4a.

[0020] like Figure 1 , 2 As shown in Figures 4 and 5, the noise reduction assembly includes a pot-shaped expansion ring 8 and multiple pieces of noise reduction cotton 9 attached to the outer arc surface of the expansion ring 8. Multiple limiting ribs 8a are provided on the outer arc surface of the expansion ring 8 to separate the multiple pieces of noise reduction cotton 9. The top of the expansion ring 8 is provided with a downwardly extending columnar body 8b. The columnar body 8b is provided with an axial through hole as an exhaust hole 8c. The lower ends of the expansion ring 8 and the upper cover 4 are provided with annular bosses for installation onto the upper end face of the stator 2. The lower surface of the annular boss of the expansion ring 8 is also provided with a downwardly protruding sealing ring 8d. The upper end face of the stator 2 is provided with a sealing groove 2a corresponding to the sealing ring 8d.

[0021] In this embodiment, an air storage chamber 5 is added to the motor flange. Gas can enter the air storage chamber 5 inside the motor flange through the air inlet. Then, an impeller 3 replaces the traditional rotor and blades. The impeller 3 is installed on the motor shaft and can be secured with a nut 10. The assembly is convenient and no clearance adjustment is required. The impeller 3 includes a hub and multiple blades fixed on the hub. Driven by the rapid rotation of the motor shaft, the blades 3 continuously scoop out the gas in the air storage chamber 5 of the motor flange, thereby forming a vacuum. Since the outer end of the blades of the impeller 3 has a small clearance fit with the inner wall of the stator 2, direct friction between the two is avoided. This reduces the heat and noise caused by friction and solves the jamming problem after the blades wear down. It has low motor power requirements, low temperature rise, and good reliability. Since both the top cover 4 and the silencing assembly are inverted pot-shaped structures, they can provide comprehensive coverage and silencing for the gas expansion chamber 7. Because the expansion ring 8 and the top cover 4 cover the impeller 3, and the expansion ring 8 has an exhaust hole 8c at the top, the high-pressure gas scooped out by the impeller 3 when it rotates will expand the expansion ring 8. The expansion ring 8 will then exert pressure on the silencing cotton 9, forcing it to adhere tightly to the inner wall of the top cover 4. This means that the high-pressure gas can only be discharged outward by passing through "exhaust hole 8c - silencing cotton 9 - exhaust port 4a" in sequence. In addition, the silencing cotton 9 is in a compressed state, which can better absorb noise and reduce the noise when the vacuum pump is venting.

[0022] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present technical solution are within the protection scope of the present invention.

[0023] To facilitate understanding by those skilled in the art of the improvements of this invention over the prior art, some of the accompanying drawings and descriptions have been simplified, and for clarity, some other elements have been omitted from this application. Those skilled in the art should realize that these omitted elements may also constitute the content of this invention.

Claims

1. A low-noise electronic vacuum pump, characterized in that: The device includes a motor (1), a stator (2), an impeller (3), a silencing assembly, and a top cover (4). The motor flange has an air storage chamber (5) and an air inlet. The stator (2) is fixedly mounted on the motor flange. The impeller (3) is fixedly mounted on the motor shaft and located within the cavity of the stator (2). The top cover (4) is fixedly mounted on the upper end face of the stator (2). The silencing assembly is installed inside the top cover (4). The impeller (3) includes a hub and multiple blades fixed to the hub. The outer ends of the multiple blades are fitted with a small clearance to the inner wall of the stator (2). A gas expansion chamber (7) is formed between the impeller (3) and the top cover (4). Both the top cover (4) and the silencing assembly... The upper cover (4) is an inverted pot-shaped structure covering the silencing component. The top of the silencing component is provided with an exhaust hole, and the lower part of the upper cover (4) is provided with multiple air outlets (4a). The silencing component includes a pot-shaped expansion ring (8) and multiple pieces of sound-absorbing cotton (9) attached to the outer arc surface of the expansion ring (8). Multiple limiting ribs (8a) are provided on the outer arc surface of the expansion ring (8) to separate the multiple pieces of sound-absorbing cotton. The top of the expansion ring (8) is provided with a downwardly extending column (8b). The column (8b) is provided with an axial through hole as an exhaust hole (8c). The lower ends of the expansion ring (8) and the upper cover (4) are provided with annular bosses for installation onto the upper end face of the stator (2).

2. The low-noise electronic vacuum pump according to claim 1, characterized in that: The lower surface of the annular boss of the expansion ring (8) is also provided with a downward protruding sealing ring (8d), and the upper end face of the stator (2) is provided with a sealing groove (2a) corresponding to the sealing ring (8d).

3. The low-noise electronic vacuum pump according to claim 1 or 2, characterized in that: The top cover (4) is made of aluminum.

4. The low-noise electronic vacuum pump according to claim 1 or 2, characterized in that: The air inlet is equipped with a one-way valve (6).

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