Small motor front end cover fixing structure and installation method

Abstract

The application relates to the field of electric machines, in particular to a small-sized electric machine front end cover fixing structure and a mounting method, which comprises a front end cover, a fixing plate, a brush holder plate and a machine shell, a side wall of the front end part of the machine shell is provided with a groove, the groove is provided with a limiting structure located at the side wall of the groove, the fixing plate is clamped in the groove and axially limited by the limiting structure, the side edge of the front end cover is clamped in the groove, and the front end cover is connected with the fixing plate through screws, and the side edge of the brush holder plate is fixed in the groove and located below the fixing plate. The fixing plate is provided, a corresponding groove is machined on the machine shell, the fixing plate and the front end cover are fixed to provide axial force for the bearing, the fixing plate and the front end cover are connected through short screws, sufficient strength and rigidity can be provided, the brush holder plate can be misaligned, interference with the brush holder plate is avoided, the compactness and strength of the structure are improved, and installation is facilitated.

Description

Technical Field

[0001] This invention relates to the field of electric motors, and in particular to a fixing structure and installation method for the front end cover of a small electric motor. Background Technology

[0002] DC motors can be classified into large, medium, and small DC motors according to their size. Motors with an armature core outer diameter of 990mm or more are large DC motors; motors with an armature core outer diameter of 368–990mm are medium DC motors; and motors with a center height of 400mm or less, or an armature core outer diameter of 368mm or less, are small DC motors. For small motors, the radial size is limited. When installing a large number of brush holders and magnets, the remaining space is small, making it difficult to pass long screws for fixing. If long screws are used, the bolt specifications are not suitable; even if the length requirement is met, the screw diameter is too small, resulting in insufficient strength. Therefore, the front cover of small motors needs to be directly fixed to the housing to avoid using thin, long screws with insufficient strength and rigidity.

[0003] For example, Chinese invention patent application number 202011526694.4, entitled "A Small Motor Assembly Installation Structure and Motor," includes a housing. A stator is installed inside the housing, and a left end cover is fixedly installed on one side of the housing, while a right end cover is fixedly installed on the other side. A rotor is disposed inside the stator, and a rotating shaft is installed at the axis of the rotor, passing through the left and right end covers. A fan is fitted onto one side of the left end cover, located outside the rotating shaft, and a fan shroud is fixedly installed on the outside of the fan. A second fixing component is disposed on one side of the left end cover, used to fix the left end cover and the housing. This invention has a reasonable structure and is simple to operate. The two fixing components enable quick installation and disassembly of the left and right end covers and the housing, as well as the fan shroud and the housing, effectively improving work efficiency. However, for scenarios with significant vibration and requiring sufficient connection strength, this invention cannot provide adequate connection strength. Summary of the Invention

[0004] The present invention aims to provide a fixing structure and installation method for the front cover of a small motor. A fixing plate is provided, and a corresponding groove is machined on the housing. The fixing plate is fixed to the front cover to provide axial force for the bearing. The fixing plate and the front cover are connected by short screws, which can provide sufficient strength and rigidity. At the same time, it can be misaligned with the brush holder plate without interfering with the brush holder plate, which improves the compactness and strength of the structure and facilitates installation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a small motor front end cover fixing structure, including a front end cover, a fixing plate, a brush holder plate and a housing, wherein a groove is provided on the side wall of the front end of the housing, and a limiting structure is provided in the groove. The fixing plate is engaged in the groove and is axially limited by the limiting structure. The side of the front end cover is engaged in the groove and the front end cover is connected to the fixing plate by screws. The side of the brush holder plate is fixed in the groove and is located below the fixing plate. By machining grooves into the housing, the fixed plate and brush holder plate are fixed using the limiting structure formed by the grooves. The fixed plate is fixed by the limiting structure, thus limiting the axial direction of the fixed plate. At the same time, the fixed plate and the front cover are connected by screws, so that the front cover and the fixed plate fit together to clamp the limiting structure, so that the axial limiting is transmitted to the front cover. Then, the structure of the front cover engaging in the groove simultaneously limits the circumferential direction of the fixed plate. At this time, the front cover limits the fixed plate both circumferentially and axially. The front cover, fixed plate, and limiting structure form a mortise and tenon structure. The front cover itself provides multi-directional locking. At this time, the brush holder plate is fixed at the bottom of the groove. The locking structure of the front cover prevents the axial movement of the brush holder plate. The structure is simple, easy to install, and the connection is reliable. It can withstand sufficient axial load, reduce the impact of motor vibration, and avoid the problem of insufficient strength and rigidity caused by using long screws to install and fix small motors.

[0006] Preferably, a notch is formed on one side of the groove along the circumference of the housing, and the notch is located in the middle of the side of the groove to form the limiting structure. A baffle is provided on the side of the fixing plate, and the baffle is engaged in the notch. The limiting structure is achieved by the notch, which is simple in structure and can well hold the fixing plate in place, limiting the fixing plate by the fit.

[0007] Preferably, the grooves are symmetrically arranged on both sides of the housing radially, and the baffles are symmetrically arranged on both sides of the fixed plate. The symmetrical arrangement of the two sides, in conjunction with the shape of the groove on one side, helps to improve the overall connection strength, ensures the static balance of the rotating body, and locates the center of rotation at the centroid, resulting in a more stable structure. Simultaneously, the symmetrical arrangement of screws allows the short screws to avoid the brush holder and magnetic poles on the brush holder plate after connection, while also contributing to static balance.

[0008] Preferably, the top and bottom sides of the slot are horizontally positioned, and the width of the slot along the circumference of the casing is greater than the width of the baffle. The horizontal position of the top and bottom sides of the slot allows the baffle to fit tightly against the casing, thus providing a better limiting effect. At the same time, the width of the slot being greater than the width of the baffle allows the baffle to fully enter the slot, thereby making room for the front cover. The front cover can then be inserted into the groove and positioned on the side of the slot, thus circumferentially limiting the baffle.

[0009] Preferably, the front cover fixing structure of the small motor includes a rotating shaft and a bearing. The rotating shaft passes through the center of the brush holder plate and the fixing plate, and the bearing is fixed between the fixing plate and the front cover. The bearing is fixed between the front cover and the fixing plate, so that the distance between the front cover and the fixing plate is limited to a range less than or equal to the thickness of the bearing. When the front cover and the fixing plate are clamped together, it is necessary to ensure that the bearing is axially limited and fixed.

[0010] Preferably, the brush holder plate is provided with a support arm, the upper end face of which is at the same level as the upper end face of the brush holder plate. The thickness of the support arm is less than the thickness of the brush holder plate, and the lower end face of the support arm contacts the bottom of the groove. Several raised ribs are provided on the lower end face of the support arm to tightly connect the brush holder plate to the housing. The raised ribs increase the friction at the connection between the brush holder plate and the housing, ensuring tight contact and forming a contact point. This allows the capacitor leads on the brush holder plate to be pressed against the housing through the raised ribs, forming a housing shield to prevent electromagnetic interference and meet the motor's EMC requirements.

[0011] Preferably, the ribs are arranged along the radial direction of the brush holder plate, and the ribs do not extend beyond the lower end face of the brush holder plate. Arranging the ribs along the radial direction of the brush holder plate ensures that the ribs at the contact points between the support arm and the housing are dotted, aiding in contact and facilitating the contact between the brush holder plate and the housing. Multiple ribs form multiple contact points, ensuring that the brush holder plate can contact the housing, further improving contact stability and meeting the requirement that the capacitor pins on the brush holder plate form a housing shield with the housing.

[0012] An installation method for the aforementioned small motor front cover fixing structure includes the following steps: a) inserting the brush holder plate into the groove of the frame; b) inserting the fixing plate into the groove of the frame and rotating the fixing plate to insert it into the limiting structure; c) inserting the front cover into the groove and fixing the front cover and the fixing plate together with screws. After inserting the brush holder plate into the groove, the fixing plate is used to initially position the brush holder plate downwards, ensuring that the lower end face of the support arm of the brush holder plate is tightly fitted with the bottom of the groove. Then, the fixing plate is rotated to make room for the front cover, and the brush holder plate is axially positioned by pressing in the front cover. The front cover and the fixing plate are fixed with screws, forming a clamping effect on the housing at both ends, thus fixing the front cover to the housing. This avoids the need for long screws to fix the front cover and rear cover; only short screws are needed to fix the housing and the fixing plate, meeting the rigidity requirements. The structure is simple and easy to install, solving the problems of insufficient rigidity and easy interference with the magnets inside the motor when using long screws for installation in small motors.

[0013] Preferably, after inserting the fixing plate into the limiting structure in step b), it is necessary to ensure that the fixing plate is fully inserted into the limiting structure to prevent interference with the installation of the front cover in step c). After the front cover is inserted into the groove, it blocks the fixing plate on one side of the circumference. Rotating the fixing plate not only makes room for the fixing plate but also allows the front cover to extend into the groove. The side wall of the front cover circumferentially limits the fixing plate, facilitating alignment of the fixing plate and the front cover, thereby better installing the screws.

[0014] The advantages of this invention are: a fixing plate is provided, and a corresponding groove is machined on the housing to fix the fixing plate to the front cover to provide axial force for the bearing. The fixing plate and the front cover are connected by short screws, which can provide sufficient strength and rigidity. At the same time, it can be misaligned with the brush holder plate without interfering with the brush holder plate, which improves the compactness and strength of the structure and facilitates installation. Attached Figure Description

[0015] Figure 1 This is a front view of the assembled small motor front cover fixing structure of the present invention.

[0016] Figure 2 This is a front view of the small motor front end cover fixing structure (exploded view) of the present invention.

[0017] Figure 3 This is an axonometric view of the small motor front end cover fixing structure (exploded view) of the present invention.

[0018] Figure 4 This is a flowchart illustrating the installation method of the small motor front end cover fixing structure of the present invention. Detailed Implementation

[0019] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0020] Depend on Figure 1 and Figure 2 and Figure 3As shown, a fixing structure for a front cover 1 of a small motor includes a front cover 1, a fixing plate 2, a brush holder plate 3, and a housing 4. A groove 5 is provided on the side wall of the front end of the housing 4. A limiting structure is provided in the groove 5. The fixing plate 2 is engaged in the groove 5 and is axially limited by the limiting structure. The side of the front cover 1 is engaged in the groove 5 and the front cover 1 is connected to the fixing plate 2 by screws. The side of the brush holder plate 3 is fixed in the groove 5 and is located below the fixing plate 2. By machining a groove 5 on the housing 4, the fixing plate 2 and brush holder plate 3 are fixed using the limiting structure formed by the groove 5. The fixing plate 2 is fixed by the limiting structure, so that the axial direction of the fixing plate 2 is limited. At the same time, the fixing plate 2 and the front cover 1 are connected by screws, so that the front cover 1 and the fixing plate 2 fit together to clamp the limiting structure, so that the axial limiting is transmitted to the front cover 1. Then, the structure of the front cover 1 snapping into the groove 5 is used to limit the circumferential direction of the fixing plate 2. At this time, the front cover 1 limits the circumferential and axial directions of the fixing plate 2. The front cover 1, the fixing plate 2 and the limiting structure form a mortise and tenon structure. At the same time, the structure of the front cover 1 itself is used for multi-directional locking. At this time, the brush holder plate 3 is fixed at the bottom of the groove 5. The locking structure of the front cover 1 prevents the axial movement of the brush holder plate 3. The structure is simple, easy to install, and the connection is reliable. It can withstand sufficient axial load, reduce the impact of motor vibration, and avoid the problem of insufficient strength and rigidity caused by using long screws to install and fix small motors.

[0021] Depend on Figure 1 and Figure 2 As shown, a slot 51 is formed on one side of the groove 5 along the circumference of the housing 4. The slot 51 is located in the middle of the side of the groove 5, forming a limiting structure. A baffle 21 is provided on the side of the fixing plate 2, and the baffle 21 is engaged in the slot 51. The groove 5 is symmetrically arranged on both sides of the radial direction of the housing 4, and the baffle 21 is symmetrically arranged on both sides of the fixing plate 2. The upper and lower sides of the slot 51 are horizontally arranged, and the width of the slot 51 along the circumference of the housing 4 is greater than the width of the baffle 21. The limiting structure achieved by the slot 51 is simple in structure and can effectively engage the fixing plate 2, limiting the fixing plate 2 through the fit. The symmetrical arrangement of the two sides of the slot 51, in accordance with the shape of one side, helps to improve the overall connection strength, making the rotating body statically balanced, with the center of rotation located at the centroid, resulting in a more stable structure. At the same time, the symmetrical arrangement of screws allows the short screws to avoid the brush holder and magnetic pole on the brush holder plate 3 after connection, while also playing a role in static balance. The horizontal upper and lower sides of the slot 51 allow the baffle 21 to fit tightly against each other, thus better achieving the limiting effect. Meanwhile, the width of the slot 51 is greater than the width of the baffle 21, allowing the baffle 21 to fully enter the slot 51, thereby making room for the front cover 1. The front cover 1 can be inserted into the groove 5 and located on the side of the slot 51, thus circumferentially limiting the baffle 21.

[0022] Depend on Figure 3 As shown, the fixing structure of the front cover 1 of the small motor includes a rotating shaft 7 and a bearing 8. The rotating shaft 7 passes through the center of the brush holder plate 3 and the fixing plate 2, and the bearing 8 is fixed between the fixing plate 2 and the front cover 1. The bearing 8 is fixed between the front cover 1 and the fixing plate 2, so that the distance between the front cover 1 and the fixing plate 2 is limited to a range less than or equal to the thickness of the bearing 8. When the front cover 1 and the fixing plate 2 are clamped together, it is necessary to ensure that the bearing 8 is axially limited and fixed. The brush holder plate 3 is provided with a support arm 31. The upper end face of the support arm 31 is at the same level as the upper end face of the brush holder plate 3. The thickness of the support arm 31 is less than the thickness of the brush holder plate 3, and the lower end face of the support arm 31 contacts the bottom of the groove 5. The lower end face of the support arm 31 is provided with three protruding ribs 6. The protruding ribs 6 are used to tightly connect the brush holder plate 3 and the housing 4. The protruding ribs 6 are arranged along the radial direction of the brush holder plate 3, and the protruding ribs 6 do not exceed the lower end face of the brush holder plate 3. The rib 6 is provided to increase the friction at the connection between the brush holder plate 3 and the housing 4, and to make the brush holder plate 3 and the housing 4 in close contact to form a contact point. The capacitor pins on the brush holder plate 3 are pressed against the housing 4 by the rib 6 to form a shield for the housing 4, avoiding electromagnetic interference and meeting the EMC requirements of the motor.

[0023] Depend on Figure 4 As shown, an installation method for the aforementioned fixing structure of the front cover 1 of a small motor includes the following steps: a) inserting the brush holder plate 3 into the groove 5 of the frame; b) inserting the fixing plate 2 into the groove 5 of the frame and rotating the fixing plate 2 to insert it into the limiting structure; c) inserting the front cover 1 into the groove 5 and fixing the front cover 1 and the fixing plate 2 together with screws. After the brush holder plate 3 is inserted into the groove 5, the brush holder plate 3 is initially positioned downwards by the fixing plate 2 to ensure that the lower end face of the support arm 31 of the brush holder plate 3 is tightly fitted with the bottom of the groove 5. Then, the fixing plate 2 is rotated to make way for the front cover 1. The brush holder plate 3 is axially positioned by pressing in the front cover 1. The front cover 1 and the fixing plate 2 are fixed with screws, forming a clamping effect on the housing 4 at both ends, thus fixing the front cover 1 and the housing 4. This avoids the need to use long screws to fix the front cover 1 and the rear cover. Only short screws are needed to fix the housing 4 and the fixing plate 2, which meets the rigidity requirements. The structure is simple and easy to install, solving the problems of insufficient rigidity and easy interference with the magnets inside the motor when using long screws in small motors.

[0024] After inserting the fixing plate 2 into the limiting structure in step b), ensure that the fixing plate 2 is fully inserted into the limiting structure to prevent interference with the installation of the front cover 1 in step c). After the front cover 1 is inserted into the groove 5, it blocks the fixing plate 2 on one side of its circumference. Rotating the fixing plate 2 not only makes room for it but also allows the front cover 1 to extend into the groove 5. The side wall of the front cover 1 provides circumferential limiting for the fixing plate 2, facilitating alignment between the fixing plate 2 and the front cover 1, thus enabling better screw installation.

Claims

1. A fixing structure for the front cover of a small motor, characterized in that: The device includes a front cover, a fixing plate, a brush holder plate, and a housing. The front end of the housing has a groove on its side wall, and a limiting structure is located in the groove. The fixing plate is engaged in the groove and is axially limited by the limiting structure. The side of the front cover is engaged in the groove and the front cover is connected to the fixing plate by screws. The side of the brush holder plate is fixed in the groove and located below the fixing plate. A groove is formed on one side of the groove along the circumference of the housing. The groove is located in the middle of the side of the groove to form the limiting structure. A baffle is provided on the side of the fixing plate, and the baffle is engaged in the groove. It also includes a rotating shaft and a bearing. The rotating shaft passes through the center of the brush holder plate and the fixing plate, and the bearing is fixed between the fixing plate and the front cover. The brush holder plate is provided with a support arm. The upper end face of the support arm is at the same level as the upper end face of the brush holder plate. The thickness of the support arm is less than the thickness of the brush holder plate, and the lower end face of the support arm contacts the bottom of the groove. The lower end face of the support arm is provided with several ribs. The ribs are used to tightly connect the brush holder plate to the housing, so that the capacitor pins on the brush holder plate are pressed against the housing through the ribs to form a housing shield, avoiding electromagnetic interference and meeting the motor EMC requirements.

2. The small motor front end cover fixing structure according to claim 1, characterized in that... The grooves are symmetrically arranged on both sides of the radial direction of the housing, and the baffles are symmetrically arranged on both sides of the fixed plate.

3. The small motor front end cover fixing structure according to claim 1 or 2, characterized in that: The slot is horizontally positioned on both the top and bottom sides, and the width of the slot along the circumference of the casing is greater than the width of the baffle.

4. The small motor front end cover fixing structure according to claim 1, characterized in that: The raised ribs are arranged along the radial direction of the brush holder plate, and the raised ribs do not exceed the lower end face of the brush holder plate.

5. An installation method for the front end cover fixing structure of the small motor as described in claims 1-4, characterized in that... Includes the following steps: a) Insert the brush holder plate into the groove of the frame; b) Insert the fixing plate into the groove of the frame and rotate the fixing plate to engage with the limiting structure; c) Insert the front cover into the groove and secure the front cover and fixing plate together with screws.

6. The installation method according to claim 5, characterized in that: After the fixing plate is inserted into the limiting structure in step b), it is necessary to ensure that the fixing plate is completely inserted into the limiting structure to prevent interference with the installation of the front cover in step c). After the front cover is inserted into the groove, it will block the front cover on one side of the circumferential direction of the fixing plate.

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