Miniature shield pump

Abstract

A miniature shield pump comprises an impeller rotor assembly composed of a rotor with a permanent magnet magnetic ring and an impeller in coaxial transmission with the rotor, the impeller is formed through injection molding and connected to the end face of the magnetic ring to form the impeller rotor assembly, and the impeller rotor assembly is provided with a front end cover plate and a rear end cover plate which cover the end face of the magnetic ring during injection molding. The permanent magnet magnetic ring is characterized in that the magnetic ring is made of ferrite materials, the periphery of the magnetic ring is sleeved with a steel sleeve, the thickness of the steel sleeve is 0.1-0.3 mm, the permanent magnet magnetic ring cannot fall off even if the permanent magnet magnetic ring with the hidden crack defect cracks, the shield pump can still be normally used, the service life is remarkably prolonged, air gaps are not affected, and the torque of a motor is not reduced.

Description

Technical Field

[0001] The invention relates to a miniature shielded pump, which can be classified into F04D13 / 06, F04D29 / 18 or F04D29 / 58 in IPC classification. Background Art

[0002] At present, the coolant circulation system of electric vehicles generally uses a miniature shielded pump. The rotor magnetic material of the pump uses a magnetic ring made of sintered ferrite as an insert, which is integrally injection molded into an impeller rotor assembly. The two ends of the magnetic ring are plastic-coated but the outer periphery is not plastic-coated to minimize the air gap and enhance the electromagnetic force. However, the structure of the rotor ferrite magnetic ring with plastic-coated ends has the following problems:

[0003] The magnetic ring is made of sintered ferrite powder with low strength. The large injection pressure during injection molding squeezes the magnetic ring, which may cause cracking, breakage, and crushing to a small number of magnetic rings with low sintering strength, increasing the cost of scrap loss and the manufacturing cost of manual crack detection. In particular, there is a risk of malfunction and failure of magnetic ring products with hidden cracks that are difficult to detect when they flow into water pumps made in subsequent processes.

[0004] Similar designs to the present invention can be found in Chinese patent documents CN211830365U, CN211501069U, CN115102312A, etc.

[0005] For relevant terminology and common knowledge, please refer to the national standard GB / T 33925.1 "General terms, definitions, quantities, characters and units for liquid pumps and their devices Part 1: Liquid pumps" and GB / T 7021 "Terminology of centrifugal pumps", the machinery industry standard JB / T5415 "Miniature centrifugal electric pumps", the 1992 edition of "IEC Electrical and Electronic Standard Terms Dictionary" published by China Standards Press, the 1983 or 1997 editions of "Mechanical Engineering Handbook" and "Electrical Engineering Handbook" published by Machinery Industry Press, the 2014 edition of "Pump Theory and Technology" published by Machinery Industry Press, the 2011 edition of "Modern Pump Theory and Technology" published by China Aerospace Press, and the 2008 edition of "Pumps and Fans" published by China Electric Power Press. Summary of the invention

[0006] To solve the above problems, the present invention provides the following technical solutions: a miniature shielded pump, comprising an impeller-rotor assembly consisting of a rotor having a permanent magnet magnetic ring and a coaxially driven impeller of an electric motor, the impeller being injection molded and the end face connected to the magnetic ring forming the impeller-rotor assembly, the impeller-rotor assembly having a front end cover plate and a rear end cover plate formed to cover the end face of the magnetic ring during the injection molding, characterized in that: the magnetic ring is made of ferrite material, a steel sleeve is sleeved on the outer periphery of the magnetic ring, the thickness of the steel sleeve is 0.1 to 0.3 mm, the steel sleeve plays a role of wrapping and protecting the magnetic ring, even if the permanent magnet magnetic ring with hidden crack defects cracks, it will not fall off, the shielded pump can still be used normally, the working life is significantly extended, and the air gap is not affected and the motor torque is not reduced.

[0007] One of the typical optimized designs of this technical solution is: the steel sleeve is interference fit with the magnetic ring, both ends of the magnetic ring are chamfered, both ends of the steel sleeve are formed into flanges covering the chamfer and / or end face according to the shape of the chamfer and / or end face of one end of the magnetic ring, and the steel sleeve is made of stainless steel material to further increase the wrapping firmness from the outer periphery and both ends of the magnetic ring.

[0008] The second typical optimization design of this technical solution is: the steel sleeve is interference fit with the magnetic ring, shoulders are provided at both ends of the magnetic ring, plastic flanges are formed on the shoulders by injection molding, the plastic flanges are connected to the front end cover plate or the rear end cover plate, both ends of the steel sleeve are flanged toward the front end cover plate or the rear end cover plate, the steel sleeve is made of stainless steel material, the front and rear end covers and the plastic flanges and the metal flanges of the steel sleeve further increase the wrapping firmness from the outer periphery and both ends of the magnetic ring.

[0009] A further optimized design may be: annular grooves are provided on both end surfaces of the magnetic ring, and the annular convexities formed by injection molding in the annular grooves are connected to the front cover plate or the rear cover plate, thereby further strengthening the firmness of the front and rear cover plates in clamping the ferrite magnetic ring, and preventing the core block from falling off even if the magnetic ring has local longitudinal cracks.

[0010] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional view of the micro shielded pump according to embodiment 1 of the present invention.

[0012] Figure 2 It is an exploded view of the impeller rotor assembly of the micro shielded pump according to Example 1 of the present invention.

[0013] Figure 3 This is an exploded view of the impeller rotor assembly of the micro-shielded pump in embodiment 1 of the present invention from another perspective.

[0014] Figure 4It is a cross-sectional view of the impeller rotor assembly of the micro shielded pump according to embodiment 1 of the present invention.

[0015] Figure 5 yes Figure 4 Partial magnification Figure Ⅰ .

[0016] Figure 6 yes Figure 4 Partial magnification Figure II .

[0017] Figure 7 yes Figure 2 A three-dimensional image of a magnetic ring used as an injection molded insert.

[0018] Figure 8 yes Figure 2 Three-dimensional image of another magnetic ring used as an injection molded insert.

[0019] Fig. 9 It is a cross-sectional view of the impeller rotor assembly of the micro shielded pump according to embodiment 2 of the present invention.

[0020] Fig.10 yes Fig. 9 A cross-sectional view of a magnetic ring used as an injection molded insert.

[0021] Reference numerals:

[0022] Impeller rotor assembly 100, pump body 2, pump shaft 3, pump cover 4,

[0023] Magnetic ring 110, chamfer 111, annular groove 112, groove 112', shaft shoulder 113,

[0024] Bushing 120,

[0025] Steel sleeve 130, flange 131,

[0026] Injection molded body 140 , impeller 141 , front end cover plate 142 , rear end cover plate 143 , annular protrusion 144 , and plastic flange 145 . DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively below in conjunction with embodiments.

[0028] Example 1

[0029] The miniature shielded pump used in the electric vehicle coolant circulation system is a permanent magnet motor coaxial drive impeller, and its structure is as follows: Figure 1As shown, it includes an impeller rotor assembly 100, a pump body 2 made of a stator as an insert, a pump shaft 3 and a pump cover 4. The pump body 2 and the pump cover 4 enclose a cavity to accommodate the impeller rotor assembly 100 and the pump shaft 3. One end of the pump shaft 3 is fixedly pivoted to the pump body 2, and the other end is pivoted to the pump cover 4. The impeller rotor assembly 100 is sleeved on the pump shaft 3 and rotates at a high speed driven by the electromagnetic force of the stator to drive the liquid to flow.

[0030] Figures 2 to 7 is a schematic diagram of the impeller rotor assembly structure, see Figure 2-4 The impeller rotor assembly 100 includes a magnetic ring 110, a shaft sleeve 120, a steel sleeve 130, and an injection molded body 140. The magnetic ring 110 is made of ferrite powder by molding, and is a hollow ring column. The two ends are chamfered 111, and an annular groove 112 is provided on the two end surfaces. The magnetic ring 110 and the shaft sleeve 120 are inserted into a mold for integral injection molding to form the injection molded body 140. The injection molded body 140 includes an impeller 141 and a front end cover plate 142 and a rear end cover plate 143 covering the two end surfaces of the magnetic ring 110, and an annular protrusion 144 connecting the front and rear end covers and embedded in the annular grooves 112 at both ends of the magnetic ring 110. The outer periphery of the magnetic ring 120 remains exposed and uncovered. The cover is made of plastic, and a steel sleeve 130 is sleeved on the outer periphery of the magnetic ring 120, and the combination is an impeller rotor assembly 100 including a rotor with a magnetic ring and an impeller 141 coaxially fixed to the rotor. The magnetic ring 120 and the steel sleeve 130 are sleeved with interference fit, and the thickness of the steel sleeve 130 is 0.1-0.3 mm. One end of the steel sleeve 130 is formed with a flange 131 and covered according to the chamfer 111 at one end of the magnetic ring 110, and the other end of the steel sleeve 130 is formed with a flange 131 and covered according to the end face shape of the other end of the magnetic ring 110, so as to further increase the wrapping firmness. The impeller rotor assembly after being manufactured is magnetized by the magnetic ring to be a permanent magnet to realize the rotor function. In this way, even if the permanent magnet of the magnetic ring with hidden crack defects is cracked, it will not fall off, and the shielded pump can still be used normally, which significantly extends the service life. The steel sleeve is preferably made of stainless steel, which has weak magnetic conductivity and is corrosion-resistant, does not affect the rotor magnetic circuit, effectively controls the matching dimensional accuracy of the stator and rotor and the shielding wall between the two, and controls the thickness of the steel sleeve to be set to 0.1-0.3mm, which does not affect the air gap and does not reduce the motor torque. The matching of the annular groove and the annular convex strengthens the firmness of the front and rear end cover plates clamping the magnetic ring. Even if the magnetic ring has a longitudinal partial crack, it can prevent the magnetic ring from falling off, ensuring the normal use of the shielded pump.

[0031] The annular grooves 112 formed on both end surfaces of the magnetic ring 120 may also be replaced with ordinary grooves 112', such as Figure 8 As shown in another magnetic ring, during injection molding, protrusions are formed in the grooves 112' at both ends of the magnetic ring to connect the front and rear cover plates, which can also prevent large pieces of the magnetic ring from falling off.

[0032] also, Figure 2-4The impeller in the middle impeller rotor assembly is an open impeller, which becomes a closed impeller by connecting and adding a front cover plate. Furthermore, the blades on the injection molded body 140 are moved to be integrally injection molded with the front cover plate, which also falls within the concept and protection scope of the present invention.

[0033] Example 2

[0034] In other variant designs, such as Fig. 9 , 10 As shown, both ends of the magnetic ring 110 are processed along the circumference to remove material to form a shoulder 113. During injection molding, plastic flanges 145 are formed on the two shoulders 113 to connect the front and rear end cover plates. Both ends of the steel sleeve 130 are wrapped with flanges 131 toward the front end cover plate 142 or the rear end cover plate 143. In this way, the front and rear end cover plates, the plastic flanges and the metal flanges of the steel sleeve further increase the wrapping firmness from the outer periphery and both ends of the magnetic ring.

[0035] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several combinations, deformations and improvements can be made without departing from the concept of the present invention, such as various combinations of flanges at both ends and various combinations of grooves at both ends in Embodiments 1 or 2, which all belong to the protection scope of the present invention.

Claims

1. A miniature canned pump, comprising an impeller-rotor assembly (100) composed of a rotor of an electric motor having a permanent magnet magnetic ring (110) and a coaxially driven impeller (141), wherein the impeller (141) is injection molded and connected to the end face of the magnetic ring (110) to form the impeller-rotor assembly (100), and has a front end cover plate (142) and a rear end cover plate (143) formed to cover the end face of the magnetic ring (110) during the injection molding, characterized in that: The magnetic ring (110) is made of ferrite material, and a steel sleeve (130) is sleeved around the outer periphery of the magnetic ring (110), and the thickness of the steel sleeve is 0.1-0.3 mm.

2. According to claim 1, the miniature canned pump is characterized in that: The steel sleeve (130) is interference fit with the outer circumference of the magnetic ring (110).

3. The miniature canned pump according to claim 1, characterized in that: The two ends of the steel sleeve (130) are covered with flanges (131) towards the two ends of the magnetic ring (110).

4. The miniature canned pump according to claim 3, characterized in that: The magnetic ring (110) has at least one end chamfered (111), and the flange (131) is formed according to the shape of the chamfer.

5. The miniature canned pump according to claim 3, characterized in that: At least one end of the magnetic ring (110) is formed with the flange (131) according to the shape of the end surface.

6. The miniature canned pump according to claim 1, characterized in that: Shaft shoulders (113) are provided at both ends of the magnetic ring (110), and plastic flanges (145) are formed by injection molding on the shaft shoulders (113), and the plastic flanges (145) are connected to the front cover plate (142) or the rear cover plate (143).

7. The miniature canned pump according to claim 6, characterized in that: Both ends of the steel sleeve (130) are wrapped around the front end cover plate (142) or the rear end cover plate (143) with flanges (131).

8. The miniature canned pump according to claim 1, characterized in that: The steel sleeve (130) is made of stainless steel.

9. The miniature canned pump according to claim 1, characterized in that: Grooves are provided on both end surfaces of the magnetic ring (110), and the protrusions formed by injection molding in the grooves are connected to the front cover plate (142) and / or the rear cover plate (143).

10. The miniature canned pump according to claim 9, characterized in that: The groove includes an annular groove (112), and the protrusion includes an annular protrusion (144) formed in the annular groove (112).

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