A motor air-cooling and heat-dissipating structure that varies with the rotational speed

Abstract

The invention discloses an air-cooled heat dissipation structure of an electric motor that changes with the rotation speed, comprising a heat dissipation wind wheel fixed to the tail end of a permanent magnet rotor; the heat dissipation wind wheel comprises a wind wheel disk, and a plurality of variable centrifugal blades are distributed in a circular array on one side of the wind wheel disk; the variable centrifugal blades are composed of a sheet-shaped fixed knife box and a centrifugal movable blade; the heat dissipation wind wheel of the invention can automatically reduce the wind load when the motor is under low load and high rotation speed, so that the rotation speed still has a certain room for improvement, and automatically increase the effective windward area of ​​the blades under high load and low rotation speed, thereby improving the heat dissipation efficiency.

Description

Technical Field

[0001] The invention belongs to the field of motor heat dissipation. Background Art

[0002] The main characteristic of constant power motor is that it can keep the output power unchanged within a certain range. When the load changes, its speed will change accordingly. The application scenarios of constant power motor are very wide, and it is mainly suitable for occasions that require stable output power.

[0003] When the constant power motor is under high load, the permanent magnet rotor presents the characteristics of high torque and low speed, and the thermal effect of the motor will not weaken at this time. In this state, since the speed of the motor's cooling fan is consistent with that of the permanent magnet rotor, its heat dissipation effect will be weakened due to the slower speed of the cooling fan;

[0004] When the constant power motor is under low load conditions, the permanent magnet rotor exhibits the characteristics of low torque and high speed. Since the speed of the cooling fan is consistent with that of the permanent magnet rotor, the high-speed rotating cooling fan has provided excess cooling air volume. On the contrary, the resistance caused by the wind load of the high-speed rotating cooling fan restricts the further improvement of the speed of the permanent magnet rotor. Summary of the invention

[0005] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a motor air-cooling heat dissipation structure that changes with the speed, which automatically reduces the wind load under low load and high speed conditions, and automatically increases the effective windward area of ​​the blades under high load and low speed conditions.

[0006] Technical solution: To achieve the above-mentioned purpose, the present invention provides an air-cooled heat dissipation structure for an electric motor that changes with the speed, including a heat dissipation wind wheel fixed to the tail end of a permanent magnet rotor; the heat dissipation wind wheel includes a wind wheel disk, and a plurality of variable centrifugal blades are distributed in a circular array on one side of the wind wheel disk; the variable centrifugal blades are composed of a sheet-like fixed knife box and a centrifugal movable blade.

[0007] Furthermore, the fixed knife box is fixed on the wind wheel disc; a guide structure is arranged on the fixed knife box, and the centrifugal movable blade moves in the fixed knife box under the guidance of the guide structure.

[0008] Furthermore, a plurality of knife box air leakage holes are hollowed out at intervals along the length direction on the side of the fixed knife box; a plurality of blade air leakage holes are hollowed out at intervals along the length direction on the side of the centrifugal movable blade; after the centrifugal movable blade is fully inserted into the fixed knife box, the plurality of knife box air leakage holes completely overlap with the plurality of blade air leakage holes; when the blade tail section of the centrifugal movable blade is pulled out from the fixed knife box, the plurality of knife box air leakage holes are completely staggered with the plurality of blade air leakage holes.

[0009] Further, one side edge of the fixed tool magazine along the length direction near the wind wheel disc is fixedly connected to the wind wheel disc through the first guide wheel base; a second guide wheel base is fixedly provided on one side edge of the fixed tool magazine along the length direction away from the first guide wheel base; the guiding structure is arranged on the first guide wheel base and the second guide wheel base.

[0010] Further, at the end of the blade tail section of each centrifugal movable blade, a pull rod is fixedly connected along the length direction, and a spring retaining disc is fixedly connected coaxially at the end of the pull rod;

[0011] A number of sleeves extending in the radial direction are fixedly arranged in a circumferential array on the outer periphery of the central sleeve. Each spring retaining disc is coaxially located in each sleeve. At one end of each sleeve close to the axis of the wind wheel disc, a limiting solid part is provided, and at the inner wall of one end of each sleeve away from the axis of the wind wheel disc, a spring supporting inner edge is provided; a spring is sleeved outside each pull rod, and the two ends of the spring elastically push against the spring retaining disc and the spring supporting inner edge respectively.

[0012] Further, when the cooling fan rotates at a low speed or does not rotate, the spring retaining disc is in limiting contact with the limiting solid part under the pressing of the spring, and the blade tail section of the centrifugal movable blade is in a state of being pulled out from the fixed tool magazine, and at this time, a number of tool magazine air leakage holes are completely staggered from a number of blade air leakage holes;

[0013] When the cooling fan rotates at a high speed, the centrifugal movable blade moves gradually away from the axis of the cooling fan under the action of centrifugal force to overcome the spring, so that the blade tail section of the centrifugal movable blade gradually inserts into the fixed tool magazine, and a number of tool magazine air leakage holes and a number of blade air leakage holes change from being completely staggered originally to gradually tending to coincide.

[0014] Further, the fixed tool magazine includes a first tool magazine piece and a second tool magazine piece. One end of the first tool magazine piece and the second tool magazine piece away from the center of the wind wheel disc is fixedly connected through a limiting end wall; when the centrifugal movable blade is completely inserted into the gap between the first tool magazine piece and the second tool magazine piece, the limiting end wall is in limiting contact with the front end of the centrifugal movable blade.

[0015] Further, at least two groups of first shaft holes and at least two groups of second shaft holes are respectively arranged on the first guide wheel base and the second guide wheel base; the guiding structure includes a first guide wheel and a second guide wheel. Guide ring grooves are arranged on the outer peripheries of the first guide wheel and the second guide wheel. The wheel shafts of the two first guide wheels are respectively rotatably installed in the two groups of first shaft holes, and the wheel shafts of the two second guide wheels are respectively rotatably installed in the two groups of second shaft holes; the two long side contours of the centrifugal movable blade are respectively in rolling and clamping fit with the two first guide wheels and the second guide wheel; the centrifugal movable blade makes the actions of inserting into and pulling out from the fixed tool magazine under the common restraint of the two first guide wheels and the second guide wheel.

[0016] Beneficial effects: The cooling fan of the present invention can automatically reduce the wind load under the condition of low load and high speed of the motor, so that there is still a certain room for improvement in the speed. Under the condition of high load and low speed, it can automatically increase the effective windward area of the blades, thereby improving the heat dissipation efficiency. Description of the Drawings

[0017] Appendix Figure 1 is a schematic diagram of the motor of this solution;

[0018] Appendix Figure 2 is a schematic diagram of the structure of the cooling fan;

[0019] Appendix Figure 3 is a schematic diagram of the overall variable centrifugal blade;

[0020] Appendix Figure 4 is Appendix Figure 3 's cross-sectional view;

[0021] Appendix Figure 5 is a disassembly schematic diagram of the variable centrifugal blade;

[0022] Appendix Figure 6 is a schematic diagram of the structure of the fixed knife box;

[0023] Appendix Figure 7 is a schematic diagram of the variable centrifugal blade under two conditions of high speed and low speed of the motor. Specific Embodiments

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] As shown in Appendix Figures 1 to 7 A motor air-cooling heat dissipation structure that changes with the speed, such as Figure 1 includes a motor stator housing 1. The inner wall of the stator housing 1 is provided with a coil stator. A plurality of air inlets 2 are hollowed out on the end wall of the motor stator housing 1; a permanent magnet rotor 3 that cooperates with the stator coil is coaxially rotatably arranged in the motor stator housing 1. There is a heat dissipation air gap between the coil stator and the permanent magnet rotor 3. The end of the permanent magnet rotor 3 is integrally and synchronously provided with a cooling fan 4; during the rotation of the cooling fan 4, the air at its position will be stirred to rotate, so that the air at the position of the cooling fan 4 will continuously diffuse into the heat dissipation air gap between the coil stator and the permanent magnet rotor 3 under the action of centrifugal force, thereby achieving the effect of active heat dissipation.

[0026] As Figure 2 , the cooling fan 4 includes a fan disk 7 coaxially arranged with the permanent magnet rotor 3. An inner sleeve 8 is integrally arranged at the center of the fan disk 7. An axially through shaft hole 9 with a keyway for the stator shaft to pass through is coaxially arranged on the inner sleeve 8; a plurality of variable centrifugal blades 5 are circumferentially and arrayedly distributed on one side of the fan disk 7.

[0027] AsFigure 3 , 4 , 5. The variable centrifugal blade 5 is composed of a sheet-shaped fixed knife box 10 and a centrifugal movable blade 17; the fixed knife box 10 is vertically and fixedly connected to the wind wheel disc 7; a guiding structure is provided on the fixed knife box 10, and the centrifugal movable blade 17 moves in the radial direction of the wind wheel disc 7 in the fixed knife box 10 under the guiding action of the guiding structure; a plurality of knife box air leakage holes 16 are spaced and hollowed out along the length direction on the side surface of the fixed knife box 10, and the knife box air leakage holes 16; a plurality of blade air leakage holes 20 are spaced and hollowed out along the length direction on the side surface of the centrifugal movable blade 17.

[0028] After the centrifugal movable blade 17 is completely inserted into the fixed knife box 10, a plurality of knife box air leakage holes 16 and a plurality of blade air leakage holes 20 completely coincide. In this state, the effective windward surface area of the variable centrifugal blade 5 is in the smallest state, so as to reduce the wind load of each variable centrifugal blade 5 in the high-speed situation, and further enable the rotational speed of the permanent magnet rotor 3 to have further room for improvement.

[0029] When the blade tail section 17.1 of the centrifugal movable blade 17 is in the state of being pulled out from the fixed knife box 10, a plurality of knife box air leakage holes 16 and a plurality of blade air leakage holes 20 are completely staggered; in this state, the windward surface of each variable centrifugal blade 5 is jointly composed of the surface where the blade tail section 17.1 is located, the surface where the fixed knife box 10 is located, and the surface where a plurality of knife box air leakage holes 16 blocked by the centrifugal movable blade 17 are located. In this state, the effective windward surface area of the variable centrifugal blade 5 is in the largest state. At the same rotational speed, the variable centrifugal blade 5 in this state has the strongest ability to stir the air, thus ensuring the ability of the cooling fan 4 to stir the air at the position where it is located at a limited rotational speed, and further improving the cooling efficiency of the motor in this state.

[0030] One side of the fixed knife box 10 close to the wind wheel disc 7 is fixedly connected to the wind wheel disc 7 through a first guide wheel base 15 along the length direction; a second guide wheel base 14 is fixed along the length direction on the side of the fixed knife box 10 away from the first guide wheel base 15; the guiding structure is on the first guide wheel base 15 and the second guide wheel base 14; at least two groups of first shaft holes 12 and at least two groups of second shaft holes 13 are respectively arranged on the first guide wheel base 15 and the second guide wheel base 14; the guiding structure includes a first guide wheel 19 and a second guide wheel 18. Guide ring grooves are arranged on the outer circumferences of the first guide wheel 19 and the second guide wheel 18. The wheel shafts of the two first guide wheels 19 are respectively rotatably installed in the two groups of first shaft holes 12, and the wheel shafts of the two second guide wheels 18 are respectively rotatably installed in the two groups of second shaft holes 13; the two long side contours of the centrifugal movable blade 17 are respectively rollingly clamped with the two first guide wheels 19 and the second guide wheel 18; the centrifugal movable blade 17 makes the actions of inserting into and pulling out of the fixed knife box 10 under the common restraint of the two first guide wheels 19 and the second guide wheel 18.

[0031] AsFigure 6 The fixed tool magazine 10 includes a first tool magazine piece 10.1 and a second tool magazine piece 10.2. One ends of the first tool magazine piece 10.1 and the second tool magazine piece 10.2 away from the center of the wind wheel disc 7 are fixedly connected through a limiting end wall 24. When the centrifugal movable blade 17 is completely inserted into the magazine gap 11 between the first tool magazine piece 10.1 and the second tool magazine piece 10.2, the limiting end wall 24 is in limiting contact with the front end of the centrifugal movable blade 17. At the tail end of the blade tail section 17.1 of each centrifugal movable blade 17, a pull rod 21 is fixedly connected along the length direction, and a spring retaining disc 23 is fixedly connected coaxially at the end of the pull rod 21.

[0032] A plurality of sleeves 6 extending in the radial direction are fixedly arranged in a circumferential array on the outer periphery of the central sleeve 8, as Figure 4 and 5 Each spring retaining disc 23 is coaxially located in each sleeve 6. At one end of each sleeve 6 close to the axis of the wind wheel disc 7, a limiting solid part 6.2 is formed, and at the inner wall of one end of each sleeve 6 away from the axis of the wind wheel disc 7, a spring supporting inner edge 6.1 is arranged. A spring 22 is sleeved outside each pull rod 21, and two ends of the spring 22 elastically push against the spring retaining disc 23 and the spring supporting inner edge 6.1 respectively.

[0033] When the cooling air wheel 4 rotates at a low speed or does not rotate, the spring retaining disc 23 is in limiting contact with the limiting solid part 6.2 under the pressing of the spring 22. At this time, the blade tail section 17.1 of the centrifugal movable blade 17 is in a state of being pulled out from the fixed tool magazine 10, and at this time, a plurality of tool magazine air leakage holes 16 and a plurality of blade air leakage holes 20 are completely staggered. When the cooling air wheel 4 rotates at a high speed, the centrifugal movable blade 17 moves gradually away from the axis of the cooling air wheel 4 by overcoming the spring 22 under the action of centrifugal force, so that the blade tail section 17.1 of the centrifugal movable blade 17 gradually inserts into the fixed tool magazine 10, and a plurality of tool magazine air leakage holes 16 and a plurality of blade air leakage holes 20 change from being completely staggered originally to gradually tend to coincide.

[0034] Working principle: For the convenience of understanding, the load of the constant power motor is divided into two extreme cases: low load and medium load:

[0035] When the constant power motor is in a high load condition, the permanent magnet rotor 3 presents the characteristics of high torque and low speed. At this time, the thermal effect of the motor will not weaken. In this state, since the rotation speed of the cooling air wheel 4 is the same as that of the permanent magnet rotor 3, its heat dissipation effect will be weak due to the slow rotation speed of the cooling air wheel 4. Therefore, it is necessary to ensure the ability of the cooling air wheel 4 to stir the air at the position where it is located under the limited rotation speed at this time, so as to eliminate or reduce the influence brought by the thermal effect of the motor;

[0036] In this solution, when the cooling air wheel 4 rotates at a low speed, as Figure 7In the upper figure above, the centrifugal force acting on the centrifugal movable blade 17 is not sufficient to overcome the elastic force of the spring 22. The spring retaining disc 23 is in limiting contact with the limiting solid part 6.2 under the top pressure of the spring 22. At this time, the blade tail section 17.1 of the centrifugal movable blade 17 is in a state of being pulled out from the fixed knife holder 10, and at this time, a plurality of knife holder air leakage holes 16 and a plurality of blade air leakage holes 20 are completely staggered; at this time, the windward surface of each variable centrifugal blade 5 is jointly formed by the surface where the blade tail section 17.1 is located, the surface where the fixed knife holder 10 is located, and the surface where a plurality of knife holder air leakage holes 16 blocked by the centrifugal movable blade 17 are located. In this state, the effective windward surface area of the variable centrifugal blade 5 is in the largest state. Under the condition of the same rotational speed, the variable centrifugal blade 5 has the strongest ability to stir air in this state, thus ensuring the ability of the heat dissipation wind wheel 4 to stir the air at the position where it is located at a limited rotational speed, and further improving the heat dissipation efficiency of the motor in this state;

[0037] When the constant power motor is in a low-load situation, such as Figure 7 In the lower figure below, the permanent magnet rotor 3 presents the characteristics of low torque and high speed. Since the rotational speed of the heat dissipation wind wheel 4 is the same as that of the permanent magnet rotor 3, the high-speed rotating heat dissipation wind wheel 4 has provided an excessive amount of heat dissipation air volume. On the contrary, the resistance brought by the wind load of the high-speed rotating heat dissipation wind wheel 4 restricts the further improvement space of the rotational speed of the permanent magnet rotor 3. Therefore, it is necessary to reduce the wind load of the heat dissipation wind wheel 4 in the high-speed rotating state;

[0038] In this case, when the heat dissipation wind wheel 4 rotates at a high speed, the centrifugal movable blade 17 moves gradually away from the axis of the heat dissipation wind wheel 4 under the action of the centrifugal force, so that the blade tail section 17.1 of the centrifugal movable blade 17 gradually inserts into the fixed knife holder 10, and a plurality of knife holder air leakage holes 16 and a plurality of blade air leakage holes 20 gradually tend to coincide from the original complete stagger; at this time, the blade tail section 17.1, which is one of the windward surfaces of each variable centrifugal blade 5, gradually inserts into the fixed knife holder 10, resulting in a gradual reduction in the exposed area of the blade tail section 17.1. At the same time, a plurality of knife holder air leakage holes 16 originally blocked by the centrifugal movable blade 17 gradually become air leakage states due to gradually coinciding with a plurality of blade air leakage holes 20. Therefore, in the case of the high rotational speed of the heat dissipation wind wheel 4, the higher the rotational speed, the smaller the effective windward surface area of the variable centrifugal blade 5, so as to achieve the effect of reducing the wind load of each variable centrifugal blade 5 in the high-speed situation, and further enabling the rotational speed of the permanent magnet rotor 3 to have further improvement space.

[0039] The above description is only the preferred implementation manner of the present invention. It should be noted that: for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can still be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A motor air-cooling heat dissipation structure that changes with the speed, characterized in that: It comprises a heat dissipation wind wheel (4) fixed to the rear end of a permanent magnet rotor (3); the heat dissipation wind wheel (4) comprises a wind wheel disc (7), and a plurality of variable centrifugal blades (5) are distributed in a circumferential array on one side of the wind wheel disc (7); the variable centrifugal blades (5) are composed of a sheet-shaped fixed blade box (10) and a centrifugal movable blade (17); The fixed knife box (10) is fixed on the wind wheel disc (7); a guide structure is provided on the fixed knife box (10), and the centrifugal movable blade (17) moves in the fixed knife box (10) under the guidance of the guide structure; A plurality of knife box air leakage holes (16) are hollowed out at intervals along the length direction on the side of the fixed knife box (10); a plurality of blade air leakage holes (20) are hollowed out at intervals along the length direction on the side of the centrifugal movable blade (17); after the centrifugal movable blade (17) is fully inserted into the fixed knife box (10), the plurality of knife box air leakage holes (16) and the plurality of blade air leakage holes (20) are completely overlapped; when the blade tail section (17.1) of the centrifugal movable blade (17) is pulled out of the fixed knife box (10), the plurality of knife box air leakage holes (16) and the plurality of blade air leakage holes (20) are completely staggered; The tail end of the blade tail section (17.1) of each centrifugal movable blade (17) is fixedly connected to a pull rod (21) along the length direction, and the end of the pull rod (21) is fixedly connected to a spring stopper (23) coaxially; A plurality of sleeves (6) extending in a radial direction are fixedly arranged in a circular array on the outer circumference of the center sleeve (8); each spring stopper (23) is coaxially disposed in each sleeve (6); a limited solid portion (6.2) is arranged at one end of each sleeve (6) close to the axis of the wind wheel disk (7); and a spring support inner edge (6.1) is arranged on the inner wall of one end of each sleeve (6) away from the axis of the wind wheel disk (7); each pull rod (21) is covered with a spring (22); two ends of the spring (22) elastically push the spring stopper (23) and the spring support inner edge (6.1) respectively; When the heat dissipation fan wheel (4) rotates at a low speed or does not rotate, the spring stopper (23) contacts the limit solid portion (6.2) under the pressure of the spring (22), and the blade tail section (17.1) of the centrifugal movable blade (17) is in a state of being pulled out from the fixed blade box (10), and at this time, the plurality of blade box air leakage holes (16) and the plurality of blade air leakage holes (20) are completely staggered; When the heat dissipation fan wheel (4) rotates at a high speed, the centrifugal movable blade (17) overcomes the spring (22) under the action of centrifugal force and moves gradually away from the axis of the heat dissipation fan wheel (4), so that the blade tail section (17.1) of the centrifugal movable blade (17) is gradually inserted into the fixed blade box (10), and the plurality of blade box air leakage holes (16) and the plurality of blade air leakage holes (20) are changed from being completely staggered to gradually being overlapped.

2. The air-cooling heat dissipation structure of a motor that changes with the speed according to claim 1 is characterized in that: A side edge of the fixed knife box (10) close to the wind wheel disc (7) is fixedly connected to the wind wheel disc (7) via a first guide wheel base (15) along the length direction; a side edge of the fixed knife box (10) away from the first guide wheel base (15) is fixedly provided with a second guide wheel base (14) along the length direction; and the guide structure is located on the first guide wheel base (15) and the second guide wheel base (14).

3. The motor air-cooling heat dissipation structure that changes with the speed according to claim 2 is characterized by: The fixed knife box (10) comprises a first knife box piece (10.1) and a second knife box piece (10.2); the ends of the first knife box piece (10.1) and the second knife box piece (10.2) away from the center of the wind wheel disc (7) are fixedly connected via a limiting end wall (24); when the centrifugal movable blade (17) is completely inserted into the box gap (11) between the first knife box piece (10.1) and the second knife box piece (10.2), the limiting end wall (24) limits the contact with the front end of the centrifugal movable blade (17).

4. The air-cooling heat dissipation structure of a motor that changes with the speed according to claim 3 is characterized in that: At least two groups of first axial holes (12) and at least two groups of second axial holes (13) are respectively provided on the first guide wheel base (15) and the second guide wheel base (14); the guide structure comprises a first guide wheel (19) and a second guide wheel (18); the outer circumferences of the first guide wheel (19) and the second guide wheel (18) are both provided with guide ring grooves; the axles of the two first guide wheels (19) are respectively rotatably mounted in the two groups of first axial holes (12); the axles of the two second guide wheels (18) are respectively rotatably mounted in the two groups of second axial holes (13); the two long side contours of the centrifugal movable blade (17) are respectively rolled and engaged with the two first guide wheels (19) and the second guide wheel (18); the centrifugal movable blade (17) is inserted into and removed from the fixed knife box (10) under the joint constraint of the two first guide wheels (19) and the second guide wheel (18).

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