Axial flow fan with failure stalling protection

Abstract

The utility model relates to the field of fans, in particular to an axial flow fan with failure stalling protection, which is characterized in that a middle shell is supported in a fan frame, and a stator assembly is arranged in the middle shell; the rotor assembly is supported in the stator assembly; the limiting mechanism comprises a limiting wheel fixedly connected to the rotating shaft, and at least one limiting tooth is arranged on the limiting wheel; the locking claw is hinged to the middle shell, the far end of the locking claw is provided with a limiting claw tip, and the locking claw is connected with the middle shell through a detachable connecting structure. When the service life of the draught fan reaches the limit, the draught fan can stop running in time, electric leakage of the draught fan caused by abnormal running is avoided, shutdown operation of a system is facilitated, and adverse effects on equipment caused by running of the equipment using the draught fan under abnormal conditions are avoided.

Description

Technical Field

[0001] The utility model relates to the field of fans, in particular to an axial flow fan with failure-stop protection. Background Art

[0002] In current semiconductor equipment, military equipment and other fields, fans are generally used for ventilation or cooling. For these devices, high reliability of the equipment has become very important. It is one of the key factors that must be considered when designing and manufacturing these devices. The fans used for these devices on the market are all life-span parts, that is, the fans will naturally fail after running for a period of time. Moreover, due to the complexity of actual working conditions, which are generally non-single usage conditions, it is difficult to predict the actual failure time of the fan. Malignant failure phenomena include rotor breakage, bearing damage, rotor flying out, friction contact between the rotor and stator components, and winding contact wear, which can easily cause the fan to stop randomly. After stopping, the entire equipment using the fan will suffer serious failures. The fan equipment is severely damaged, the maintenance time is long, and there is even a safety hazard of fan leakage. Once it stops unexpectedly, it will cause serious consequences and may bring significant economic losses and safety problems. Utility Model Content

[0003] The purpose of the utility model is to address the deficiencies of the existing technology and provide an axial flow fan with failure shutdown protection, which can stop the fan in time when the fan life reaches its limit, avoid abnormal operation causing fan leakage, facilitate system shutdown operation, and avoid adverse effects on the equipment using the fan caused by operation under abnormal conditions.

[0004] The purpose of the utility model is to achieve the following: an axial flow fan with failure-stop protection, comprising:

[0005] A fan frame, which internally supports an intermediate housing, and in which the subassemblies are set;

[0006] a rotor assembly supported in the stator assembly and having a rotating shaft, a front end of the rotating shaft extending out of the intermediate housing and connected to an impeller hub, and the impeller hub is provided with fan blades;

[0007] Limiting mechanism, including:

[0008] A limiting wheel is fixedly connected to the rotating shaft, and the limiting wheel is provided with at least one limiting tooth;

[0009] A stop paw is hinged to the intermediate housing, a limit paw tip is arranged at a distal end of the stop paw, the stop paw is connected to the intermediate housing through a detachable connection structure, the detachable connection structure is configured to maintain the relative position of the stop paw and the intermediate housing in a normal state, and when the stop paw interferes with the limit wheel, the detachable connection structure is disconnected to allow the stop paw to deflect and further interfere with the limit tooth, thereby limiting the rotation of the rotating shaft.

[0010] A limit paw tip is arranged at a first end of the stop paw, and a driving paw tip is arranged at a second end of the stop paw, the driving paw tip is used to interfere with the limit tooth to drive the stop paw to deflect, and the corresponding arc length of the driving paw tip and the limit paw tip is smaller than the corresponding arc length of the adjacent limit tooth.

[0011] The distance from the driving paw tip to the center of rotation of the stop paw is smaller than the distance from the limit paw tip of the stop paw to the center of rotation.

[0012] The stop paw is provided with an arc-shaped slot, an opening of the arc-shaped slot is arranged on a side wall adjacent to one side of the rotating shaft, and an inner wall of the arc-shaped slot is connected to a limit pin arranged on the intermediate housing through a detachable connection structure.

[0013] The detachable connection structure is a buckle connection structure, a magnetic attraction connection structure or a pull-apart structure with a pull-apart slot.

[0014] The detachable connection structure includes a first connecting part connected to the stop paw and a second connecting part connected to the intermediate housing, the first connecting part is a magnetic tile made of a magnetic material, and the second connecting part is made of a ferromagnetic material.

[0015] The detachable connection structure includes a first connecting part connected to the stop paw and a second connecting part connected to the intermediate housing, the first connecting part and the second connecting part are integrally formed, and the first connecting part and the second connecting part are transitioned through a pull-apart slot to guide and control the disconnection of the first connecting part and the second connecting part in the pull-apart slot.

[0016] The intermediate housing includes an intermediate sleeve, a front end cover and a rear end cover, the front end cover and the rear end cover are respectively connected to two ports of the intermediate sleeve through fasteners, the rotating shaft is supported in the front end cover and the rear end cover through bearings, and the stop paw is hinged to the front end cover or the rear end cover.

[0017] The limit teeth are uniformly distributed along the circumference of the limit wheel, the bending direction of the limit teeth is the same as the rotating direction of the rotating shaft, and the face of the limit teeth facing the stop paw is concave.

[0018] The stop paw includes an arc-shaped plate-shaped main body, a hinge hole penetrating the thickness direction of the main body is arranged on the main body, the hinge hole is rotatably sleeved on a hinge shaft, and the end wall of the limit paw tip gradually narrows from the limit paw tip against the rotating direction of the rotating shaft and forms a wedge shape.

[0019] The above scheme has the following beneficial effects: the intermediate housing is used to support central components such as the stator assembly and the rotor assembly, and the rotation of the rotor drives the impeller hub to rotate, thereby driving the fan blades to rotate; the limit wheel rotates with the rotating shaft; the limit teeth provided on the limit wheel can stop the limit wheel in the circumferential direction; the stop claw can be connected to the intermediate housing in a deflectable manner and can be deflected based on the connection position to change its arrangement position so that it can interfere with the limit teeth; when the rotating shaft is about to fail, it swings and deflects, the motion trajectory of the limit teeth deviates, and then interferes with the stop claw; the stop claw contacts the limit teeth and further deflects the stop claw, so that the stop claw and the limit teeth have a larger interference amount, so that the rotation of the limit teeth is blocked, and then the rotating shaft is forced to stop quickly. The stop signal of the rapid stop is clear, which can facilitate the inverter used in the fan to send a stop signal to the host computer to realize the monitoring of the fan status and the adjustment of the working status of other heat dissipation devices.

[0020] By adopting the utility model, a series of serious failures caused by a sharp increase in the centrifugal force of the rotor can be effectively avoided by quickly identifying and stopping the fan that is about to fail in the early stage of fan operation, including failure failures caused by rotor breakage, bearing damage, rotor flying out, friction contact between the rotor and stator components, and winding wear. It can not only significantly reduce the losses caused by equipment failure, but also greatly shorten the subsequent maintenance time and reduce the difficulty of replacement, while fundamentally eliminating safety risks such as leakage.

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of an embodiment of the present utility model;

[0023] Figure 2 For this utility model Figure 1 The longitudinal section structure diagram shown;

[0024] Figure 3 For this utility model Figure 1 A schematic diagram of the cross-sectional structure of the embodiment shown;

[0025] Figure 4 Schematic diagram of the structure of the locking claw in another embodiment of the present invention.

[0026] 100 is a fan frame; 110 is a middle shell; 103 is a stator assembly; 104 is a rotor assembly; 105 is a rotating shaft; 106 is a impeller hub; 107 is a fan blade; 200 is a limiting mechanism; 210 is a limiting wheel; 211 is a limiting tooth; 220 is a stop pawl; 221 is a limiting pawl tip; 300 is a detachable connection structure; 222 is a promoting pawl tip; 223 is an arc-shaped groove; 310 is a limiting pin; 301 is a first connecting part; 302 is a second connecting part; 111 is a middle sleeve; 112 is a front end cover; 113 is a rear end cover; 122 is a fastener; 123 is a bearing; 126 is a hinged shaft. DETAILED DESCRIPTION

[0027] With reference to the drawings, the specific implementation of the present application will be described in detail.

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0029] In the description of the present application, it should be understood that the terms center, upper, lower, front, rear, left, right, vertical, horizontal, top, bottom, inner, outer and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In the description of the present application, the terms first, second, etc. are for the purpose of description only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as first and second can be used to explicitly or implicitly include one or more features. In the description of the present application, unless otherwise stated, the meaning of multiple is two or more. It should be noted that in actual application, due to the limitation of equipment precision or installation error, it is difficult to achieve absolute parallelism or perpendicularity. In the present application, the description of perpendicularity, parallelism or same direction is not an absolute limitation, but indicates that the structure can be arranged vertically or horizontally within a predetermined error range and achieve the corresponding predetermined effect, so that the technical effect of the limited features can be maximized, and the corresponding technical solution is easy to implement and has high feasibility.

[0030] In the description of this specification, reference to the terms one embodiment, some embodiments, examples, specific examples, or some examples means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0031] See also Figures 1 to 3 An embodiment of an axial flow fan with fail-safe stall protection includes a fan frame 100, a rotor assembly 104, and a limit mechanism 200, wherein the fan frame 100 internally supports an intermediate casing 110, and the intermediate casing 110 can be supported in the fan frame 100 by spokes or static blades. The setting of the static blades rectifies and guides the airflow, changes the direction of the airflow to make it more in line with system requirements, and converts part of the airflow kinetic energy into pressure energy, effectively reducing eddy currents and turbulence, reducing flow losses, improving fan efficiency and output, and stabilizing the airflow state to ensure smooth operation of the fan with lower noise. It is often used to optimize airflow organization, improve system performance, and protect downstream equipment.

[0032] The stator assembly 103 is set in the intermediate housing 110, and the rotor assembly 104 is supported in the stator assembly 103. The rotor assembly 104 has a rotating shaft 105. The front end of the rotating shaft 105 extends out of the intermediate housing 110 and is connected to an impeller hub 106. The impeller hub 106 is provided with fan blades 107.

[0033] The limiting mechanism 200 can specifically include a limiting wheel 210 and a stop pawl 220. The limiting wheel 210 is fixedly connected to the rotating shaft 105, which can be connected by a key connection, a spline, an interference, or an integral molding, etc. to transmit torque. The limiting wheel 210 is provided with at least one limiting tooth 211, which can be integrally formed with the wheel body of the limiting wheel 210. The stop pawl 220 is hinged to the middle shell 110. The distal end of the stop pawl 220 is provided with a limiting pawl tip 221. The stop pawl 220 is connected to the middle shell 110 through a detachable connection structure 300. The detachable connection structure 300 can be an elastic buckle or a magnetic attraction structure, which has a small connection force and can keep the position of the stop pawl 220 stable during normal operation, without swinging and interfering with the normal operation of the axial flow fan. The detachable connection structure 300 is configured to maintain the relative position of the stop pawl 220 and the middle shell 110 in a normal state. When the stop pawl 220 interferes with the limiting wheel 210, the detachable connection structure 300 is disconnected to allow the stop pawl 220 to deflect and further interfere with the limiting tooth 211, thereby limiting the rotation of the rotating shaft 105. As shown in Figure 3 the limiting pawl tip 221 on the stop pawl 220 interferes and contacts with the limiting tooth 211. After the detachable connection structure 300 is disconnected, the stop pawl 220 continues to be driven to deflect. The contact position of the limiting pawl tip 221 and the limiting tooth 211 moves relatively and has a larger interference amount until the limiting tooth 211 is stuck.

[0034] In some embodiments, the detachable connection structure 300 includes a first connection part 301 connected to the stop pawl 220 and a second connection part 302 connected to the middle shell 110. The first connection part 301 is a magnetic tile made of a magnetic material, specifically a neodymium iron boron magnetic tile. The second connection part 302 is made of a ferromagnetic material, specifically a metal ferromagnetic material such as iron, cobalt, nickel and their alloys, or a ferrite ferromagnetic material with iron oxide as the main component, which can be connected by magnetic attraction. When the connection objects of the first connection part 301 or the second connection part 302 are of the same material, they are connected by integral molding. For example, when the second connection part 302 is made of a magnetic material and the limiting pin 310 is made of a magnetic material, they can be integrally formed. The first connection part 301 can be of the same material as the stop pawl 220 and be integrally formed. When the second connection part 302 and the limiting pin 310 are of different materials, they can be connected by adhesion or interference embedding, etc.

[0035] Specifically in some embodiments, the detachable connecting structure 300 comprises a first connecting part 301 connected with the stop pawl 220 and a second connecting part 302 connected with the intermediate shell 110, the first connecting part 301 and the second connecting part 302 are integrally formed, and the first connecting part 301 and the second connecting part 302 are connected through a break slot to guide and control the first connecting part 301 and the second connecting part 302 to be disconnected in the break slot, the break slot can be V-shaped, U-shaped or narrow-necked structure, and the break slot can be controlled to break under overload through the preset break slot, and the break slot design can have a small connecting force in the normal state, so that the stop pawl 220 is stable and does not swing during normal operation, and the first connecting part 301 and the second connecting part 302 are separated after breaking in case of failure.

[0036] In some embodiments, the intermediate shell 110 comprises an intermediate sleeve 111, a front end cover 112 and a rear end cover 113, the front end cover 112 and the rear end cover 113 are connected to the two ends of the intermediate sleeve 111 through fasteners 122 respectively, the rotating shaft 105 is supported in the front end cover 112 and the rear end cover 113 through bearings 123, and the stop pawl 220 is hinged on the front end cover 112 or the rear end cover 113. In this embodiment, the stop pawl 220 can be located on the inner side wall of the front end cover 112 or the inner side wall of the rear end cover 113. It can also be located on the outer side wall of the front end cover 112 or the outer side wall of the rear end cover 113, and the limit wheel 210 is arranged on the rotating shaft 105 corresponding to the outer side wall of the front end cover 112 or the outer side wall of the rear end cover 113.

[0037] Of course, in some embodiments, the limit mechanism 200 is arranged at the axial position corresponding to the position of the front end cover 112 and the rear end cover 113, which can provide failure protection at both ends of the rotor assembly 104.

[0038] In some embodiments, the limit teeth 211 are uniformly distributed along the circumference of the limit wheel 210, the bending direction of the limit teeth 211 is the same as the rotating direction of the rotating shaft 105, and the front side of the limit teeth 211 facing the stop pawl 220 is concave. With this structure, a groove can be formed on the front side of the limit teeth 211, which can facilitate the radial inward movement of the limit pawl tip 221.

[0039] In some embodiments, the stop pawl 220 comprises an arc-shaped plate-shaped body, a hinge hole penetrating the thickness direction of the body is arranged on the body, the hinge hole is rotatably sleeved on the hinge shaft 126, and the end wall of the limit pawl tip 221 gradually narrows and forms a wedge shape from the limit pawl tip 221 against the rotating direction of the rotating shaft 105. With this structure, when the limit pawl tip 221 contacts the limit teeth 211, it can further facilitate the limit pawl tip 221 to wedge into the front side of the limit teeth 211, thereby limiting the limit teeth 211.

[0040] Referring to Figure 4 In some other embodiments, the difference lies in that a limiting claw tip 221 is provided at the first end of the stopping claw 220, and an actuating claw tip 222 is provided at the second end of the stopping claw 220. The actuating claw tip 222 is used to interfere with the limiting tooth 211 to drive the stopping claw 220 to deflect. The arc length corresponding to the actuating claw tip 222 and the limiting claw tip 221 is smaller than the arc length corresponding to the adjacent limiting tooth 211. Through the interference between the actuating claw tip 222 and the limiting tooth 211, the actuating claw tip 222 is knocked away, which can quickly push the stopping claw 220 to deflect and have motion inertia. The limiting claw tip 221 of the stopping claw 220 and the adjacent limiting tooth 211 have a large amount of interference on the motion trajectory before contact. When the interference is formal, the limiting tooth 211 can be quickly and stably engaged, and the rotating shaft 105 can be limited. This is particularly suitable for more subtle rotor failure situations.

[0041] In some embodiments, the distance from the actuating claw tip 222 to the rotation center of the stopping claw 220 is smaller than the distance from the limiting claw tip 221 of the stopping claw 220 to the rotation center. Through this setting, the swing amplitude of the limiting claw tip 221 can be larger than the swing amplitude of the actuating claw tip 222, with a larger interference amount, and can engage with the limiting tooth 211 more reliably.

[0042] In some embodiments, the stopping claw 220 is provided with an arc-shaped groove 223, the opening of the arc-shaped groove 223 is provided on the side wall adjacent to the rotating shaft 105, the inner wall of the arc-shaped groove 223 is connected to the limit pin 310 provided on the intermediate shell 110 through a detachable connection structure 300, and the magnetic tile can be provided in the arc-shaped groove 223.

[0043] By adopting the above solution, when the rotor of the axial flow fan begins to fail, the rotor will experience a small radial movement, and the limiting tooth 211 will interfere with the limiting claw tip 221 of the fixed stop claw 220, so that the stop claw 220 can release the detachable connection with the intermediate housing 110, and the stop claw 220 can be deflected, and then the stop claw 220 and the limiting tooth 211 are locked, and the rotating shaft 105 is stopped. By adopting the utility model, by quickly identifying and stopping the fan that is about to fail in the early stage of fan operation, a series of serious failures caused by a sharp increase in the centrifugal force of the rotor can be effectively avoided, including failure failures caused by rotor fracture, bearing 123 damage, rotor flying out, frictional contact between the rotor and stator assembly 103, and winding wear. It can not only significantly reduce the losses caused by equipment failure, but also greatly shorten the subsequent maintenance time and reduce the difficulty of replacement, while fundamentally eliminating safety risks such as leakage.

[0044] The above merely describes preferred embodiments of the present application and is not intended to limit the present application. Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the present application claims and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. An axial flow fan with fail-safe protection, characterized in that: include: A fan frame (100) internally supports an intermediate housing (110), wherein a subassembly (103) is set in the intermediate housing (110); A rotor assembly (104) is supported in the stator assembly (103) and has a rotating shaft (105). The front end of the rotating shaft (105) extends out of the intermediate housing (110) and is connected to an impeller hub (106). The impeller hub (106) is provided with fan blades (107). The limiting mechanism (200) comprises: A limiting wheel (210) is fixedly connected to the rotating shaft (105), and the limiting wheel (210) is provided with at least one limiting tooth (211); The stopping claw (220) is hinged on the intermediate housing (110), and a limiting claw tip (221) is provided at the distal end of the stopping claw (220). The stopping claw (220) is connected to the intermediate housing (110) via a detachable connection structure (300). The detachable connection structure (300) is configured to: maintain connection under normal conditions to maintain the relative position of the stopping claw (220) and the intermediate housing (110); when the stopping claw (220) interferes with the limiting wheel (210), the detachable connection structure (300) is released to allow the stopping claw (220) to deflect and further interfere with the limiting tooth (211), thereby limiting the rotation of the rotating shaft (105).

2. The axial flow fan with fail-safe protection according to claim 1, characterized in that: A limiting claw tip (221) is provided at the first end of the stopping claw (220), and an actuating claw tip (222) is provided at the second end of the stopping claw (220). The actuating claw tip (222) is used to interfere with the limiting tooth (211) to drive the stopping claw (220) to deflect. The arc length corresponding to the actuating claw tip (222) and the limiting claw tip (221) is smaller than the arc length corresponding to the adjacent limiting tooth (211).

3. The axial flow fan with fail-safe protection according to claim 2, characterized in that: The distance between the actuating claw tip (222) and the rotation center of the stopping claw (220) is smaller than the distance between the limiting claw tip (221) of the stopping claw (220) and the rotation center.

4. The axial flow fan with fail-safe protection according to claim 1, characterized in that: The locking claw (220) is provided with an arc-shaped groove (223), the opening of which is provided on a side wall adjacent to the rotating shaft (105), and the inner wall of the arc-shaped groove (223) is connected to a limiting pin (310) provided on the intermediate housing (110) via a detachable connection structure (300).

5. An axial flow fan with fail-safe protection according to any one of claims 1 to 4, characterized in that: The detachable connection structure (300) is a snap connection structure, a magnetic connection structure, or a breakaway structure with a breakaway groove.

6. An axial flow fan with fail-safe protection according to any one of claims 1 to 4, characterized in that: The detachable connection structure (300) comprises a first connection portion (301) connected to the stop claw (220) and a second connection portion (302) connected to the intermediate housing (110), wherein the first connection portion (301) is a magnetic tile made of a magnetic attraction material, and the second connection portion (302) is made of a ferromagnetic material.

7. An axial flow fan with fail-safe protection according to any one of claims 1 to 4, characterized in that: The detachable connection structure (300) comprises a first connection portion (301) connected to the stop claw (220) and a second connection portion (302) connected to the intermediate housing (110), wherein the first connection portion (301) and the second connection portion (302) are integrally formed, and a break groove is provided between the first connection portion (301) and the second connection portion (302) to guide and control the first connection portion (301) and the second connection portion (302) to be disconnected in the break groove.

8. The axial flow fan with fail-safe protection according to claim 1, characterized in that: The intermediate housing (110) includes an intermediate sleeve (111), a front end cover (112), and a rear end cover (113). The front end cover (112) and the rear end cover (113) are respectively connected to two ends of the intermediate sleeve (111) via fasteners (122). The rotating shaft (105) is supported in the front end cover (112) and the rear end cover (113) via bearings (123). The stop claw (220) is hinged to the front end cover (112) or the rear end cover (113).

9. The axial flow fan with fail-safe protection according to claim 1, characterized in that: The limiting teeth (211) are evenly distributed along the circumference of the limiting wheel (210), the bending direction of the limiting teeth (211) is the same as the rotation direction of the rotating shaft (105), and the front surface of the limiting teeth (211) facing the stopping claw (220) is in a notch shape.

10. The axial flow fan with fail-safe protection according to claim 9, characterized in that: The stop claw (220) comprises an arc-shaped plate-shaped main body, the main body is provided with a hinge hole extending through the thickness thereof, the hinge hole being rotatably sleeved on the hinge shaft (126), and the end wall of the limit claw tip (221) gradually narrows from the limit claw tip (221) in the direction opposite to the rotation direction of the rotating shaft (105) and forms a wedge shape.

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