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CN-122001136-A - Direct current motor for range hood

CN122001136ACN 122001136 ACN122001136 ACN 122001136ACN-122001136-A

Abstract

The invention discloses a direct current motor for a range hood, and aims to solve the problems of rapid sealing failure and short protection life caused by lack of redundant design of the existing shaft seal structure. The motor is provided with a shaft seal mechanism at the shaft extension end, and comprises a seal shell, a partition piece, a first seal piece and a second seal piece. The partition divides the housing interior into first and second sealed cavities. The first sealing element is always contacted with the rotating shaft to form a main seal, and the second sealing element is in an initial state and is out of contact with the rotating shaft. The shaft seal mechanism also comprises an axial driving component and a switching trigger component. When the sealing effect is reduced due to abrasion of the first sealing element, the switching assembly is triggered through motor reversal, the axial driving assembly is driven to act, the second sealing element is pushed to the working position axially, and the main sealing is replaced. According to the invention, through redundant seal design, wear compensation and intelligent triggering switching, the sealing reliability, the service life and the adaptability of the range hood motor under severe environments are obviously improved.

Inventors

  • QU JIANLUN
  • GU XUEMING
  • ZHANG YAO
  • CHEN YUNFENG
  • WANG JIE

Assignees

  • 京马电机有限公司

Dates

Publication Date
20260508
Application Date
20260410

Claims (10)

  1. 1. The utility model provides a direct current motor for lampblack absorber, includes casing (10), stator part, rotor part and pivot (20), its characterized in that, the axle of motor stretches the end and is equipped with shaft seal mechanism (100), shaft seal mechanism (100) include: A seal housing (110) fixed to the case (10); a partition member (120) installed in the seal housing (110) to partition a first seal chamber (101) and a second seal chamber (102) arranged in an axial direction; the first sealing piece (130) is arranged in the first sealing cavity (101), and a sealing lip part of the first sealing piece (130) is kept in sealing contact with the surface of the rotating shaft (20); The rotary shaft (20) is provided with an annular avoidance groove (21) at a sealing lip part corresponding to the second sealing part (140), so that the sealing lip part of the second sealing part (140) is separated from contact with the surface of the rotary shaft (20) in an initial state; An axial drive assembly (200) drivingly connected to the second seal (140) for driving the second seal (140) to move axially to a sealing position; and a switching trigger assembly (300) which is triggered in response to the reversing operation of the motor and drives the axial driving assembly (200) to act.
  2. 2. The direct current motor for a range hood according to claim 1, wherein the axial driving assembly (200) includes: a driver (210) threadedly engaged with the seal housing (110); A follower (220) axially slidably disposed within the second seal chamber (102) and drivingly connected to the second seal (140); The driving member (210) generates axial displacement through threaded engagement with the seal housing (110) when driven to rotate, and pushes the driven member (220) and the second seal member (140) to axially move.
  3. 3. The direct current motor for a range hood according to claim 2, wherein the switching trigger assembly (300) includes: A centrifugal trigger part (310) which is arranged in the rotating shaft (20) and moves from a first position to a second position under the action of centrifugal force generated when the motor rotates reversely; a transmission interface part (320) arranged on the driving piece (210); When the centrifugal trigger portion (310) moves to the second position, it engages with the transmission interface portion (320) to transfer the reverse momentum of the rotating shaft (20) to the driving member (210).
  4. 4. A direct current motor for a range hood according to claim 3, characterized in that the centrifugal trigger portion (310) comprises: the inclined chute (311) is arranged in the rotating shaft (20) and extends obliquely to the rotating direction of the rotating shaft (20) when the motor works normally; A trigger slide block (312) slidably arranged in the inclined chute (311); an engagement portion (313) provided at an extension end of the trigger slider (312); the transmission interface part (320) is a ratchet wheel coaxially and fixedly connected with the driving piece (210); When the motor is reversed, the trigger slide block (312) slides out along the inclined slide groove (311) under the action of centrifugal force, so that the meshing part (313) is meshed with the ratchet wheel.
  5. 5. The direct current motor for a range hood according to claim 4, further comprising a locking assembly (400), the locking assembly (400) being disposed in the rotating shaft (20) and comprising: a lock pin (410) which is axially slidably arranged in the rotating shaft (20) and the end part of which can extend into the inclined chute (311) to block the trigger slide block (312); a pendulum (421) swingably provided in the rotating shaft (20); A transmission mechanism (420) connecting the pendulum (421) and the lock pin (410); The transmission mechanism (420) comprises a swinging plate (422) fixedly connected with the pendulum bob (421), a guide groove (423) formed in the swinging plate (422), and a guide rod (424) with one end connected with the lock pin (410) and the other end in sliding fit in the guide groove (423), wherein the extending track of the guide groove (423) is configured to drive the swinging plate (422) to swing to a first angle under the action of centrifugal force when the motor rotates positively, and drive the lock pin (410) to extend through the cooperation of the guide groove (423) and the guide rod (424), and drive the swinging plate (422) to swing to a second angle under the action of reverse centrifugal force when the motor rotates reversely, and drive the lock pin (410) to retract.
  6. 6. The direct current motor for a range hood according to claim 5, wherein the locking assembly (400) further comprises a reset structure comprising: The clamping plate (314) is fixed at the tail end of the trigger sliding block (312) extending into the rotating shaft (20); The avoidance inclined surface (22) is formed in a channel of the lock pin (410) extending into the inclined chute (311), and the inclined direction of the avoidance inclined surface faces to the retreating path of the trigger slide block (312); A magnetic attraction piece (430) arranged in the channel for attracting the lodged lock pin (410) to return to normal; the relief ramp (22) provides a tangential rocking gap for the locking pin (410).
  7. 7. The direct current motor for a range hood according to claim 2, wherein the separator (120) is made of an easily-worn material, a frosted ring (221 a) is arranged on one side of the follower (220) facing the separator (120), and a guiding conical surface (121) is formed on one side of the separator (120) facing the first sealing member (130); When the axial driving assembly (200) is triggered to act, the grinding ring (221 a) rotates relative to the partition (120) and generates abrasion until the partition (120) is connected with the sealing shell (110) and is broken, and the driven piece (220) pushes the partition (120) to move, so that the guide conical surface (121) squeezes in and clamps the sealing lip of the first sealing piece (130).
  8. 8. The direct current motor for a range hood according to claim 7, wherein the separator (120) is a graphite sheet.
  9. 9. The direct current motor for a range hood according to claim 2, wherein an elastic buffer element (230) is arranged between the driving element (210) and the driven element (220), the elastic buffer element (230) comprises two spring discs (231), and the spring discs (231) are stacked and connected with the driving element (210) and the driven element (220) respectively; At the beginning of the axial drive assembly (200) operation, the spring disks (231) are compressed to provide axial damping and transfer rotational torque between the driver (210) and the follower (220) by friction between the disks.
  10. 10. The direct current motor for a range hood according to claim 2, wherein a circle of anti-back ribs a (501) are provided on the inner wall of the sealed housing (110), and a circle of anti-back ribs B (502) are provided on the outer wall of the driving member (210); When the driving member (210) rotates to the second sealing member (140) reaches the sealing position, the anti-back-up rib B (502) passes over the anti-back-up rib A (501) to form one-way clamping.

Description

Direct current motor for range hood Technical Field The invention relates to a motor, in particular to a direct current motor for a range hood. Background The range hood motor operates in extremely harsh environments for long periods of time and is continuously exposed to high temperature, high humidity and cooking grease and particulate rich air streams. Under the negative pressure of the fan, a large amount of oil smoke flows through the motor area, grease components therein easily permeate into the motor through an assembly gap between the rotor shaft and the stator shell, a series of problems such as winding insulation corrosion aging, electrical short circuit, poor heat dissipation and the like are caused, and the safety, the efficiency and the service life of the motor are seriously influenced. In order to cope with greasy dirt, the industry generally adopts a plastic packaging (encapsulation) technology, and core components such as a stator core, a winding and the like are integrally encapsulated by materials such as epoxy resin and the like, so that the direct contact between the greasy dirt and an electromagnetic assembly is effectively isolated. However, the plastic sealing technique cannot prevent grease from continuing to penetrate inwardly along the shaft seal region between the moving part of the shaft and the static housing. The existing shaft seal proposal mostly adopts single-layer or double-layer rubber lip-shaped sealing rings which are arranged in parallel and are in interference fit with the rotating shaft, and the sealing is carried out by means of lip elastic force. However, this design has inherent drawbacks in that all sealing rings begin to withstand pressure, friction and thermal aging simultaneously at the instant of motor start, resulting in a high convergence of wear rate and life. Once the fatigue limit is reached, the sealing rings of all layers are often failed in a short time, the sealing barrier is rapidly broken, and grease is driven in directly. In other words, the prior art lacks effective redundancy of failure and life-time echelon, and reliable staged protection cannot be achieved. Disclosure of Invention The invention aims to solve the technical problem of overcoming the defects of the prior art and providing the direct current motor for the range hood, which has redundant sealing capability, can automatically start standby sealing after failure of main sealing and can prolong the whole protection life. In order to solve the technical problems, the invention adopts the following technical scheme: a direct current motor for a range hood comprises a shell, a stator part, a rotor part and a rotating shaft. The improvement is that the shaft extension end of the motor is provided with a shaft seal mechanism. The shaft seal mechanism comprises a seal shell, a partition piece, a first seal piece, a second seal piece, an axial driving assembly and a switching trigger assembly. The sealed housing is fixed to the motor housing. The partition piece is arranged in the sealed shell and divides the inner cavity into a first sealed cavity and a second sealed cavity which are axially arranged. The first sealing element is arranged in the first sealing cavity, and the sealing lip part of the first sealing element is kept in constant contact with the surface of the rotating shaft to form a main seal. The second sealing element is arranged in the second sealing cavity, and the sealing lip part of the second sealing element is arranged at intervals with the surface of the rotating shaft in the initial state and is in the standby state. An annular avoidance groove is formed in the rotating shaft at a position corresponding to the lip part of the second sealing element so as to realize the interval. The axial driving component is in driving connection with the second sealing element and is used for responding to the trigger signal to drive the second sealing element to axially move so that the lip part of the second sealing element is in contact with the surface of the rotating shaft and enters the sealing working position. The switching trigger assembly is arranged between the rotating shaft and the axial driving assembly and is used for responding to the reversing operation of the motor to generate the trigger signal so as to drive the axial driving assembly to act. Preferably, the axial drive assembly comprises a driver and a follower. The driving piece is connected with the sealing shell through a thread structure. The driven piece is axially slidably arranged in the second sealing cavity and is connected with the second sealing piece. When the driving piece is driven to rotate, the driven piece and the second sealing piece are pushed to axially move by the axial displacement generated by the screw thread pair. Further, the switch triggering assembly includes a centrifugal triggering portion and a transmission interface portion. The centrifugal trigger part is arranged in an inclined