Inner rotor brushless motor with sealing structure

Abstract

The utility model relates to the technical field of inner rotor brushless motors, and discloses an inner rotor brushless motor with a sealing structure, which comprises a motor casing and a motor end cover, a stator assembly is mounted in the motor casing, a driving plate is mounted on a framework support of the stator assembly, and the motor end cover is clamped on the motor casing through a terminal of the driving plate. An outgoing line sealing plug is installed on the motor end cover, a sealing cover plate is installed on the outgoing line sealing plug, an installation column on the sealing cover plate is installed on the motor end cover, and a sealing gasket is installed at the gap position of the driving plate and the motor end cover. According to the utility model, the sealing performance of the inner rotor brushless motor at the motor outgoing line position and the combination position of the motor shell and the motor end cover is enhanced, the sealing performance is ensured, the reliability of the sealing of the product under the harsh conditions of high temperature, durability, cold and hot impact and the like can be ensured, and the sealing problem of the inner rotor brushless motor is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of inner-rotor brushless motors, and particularly relates to an inner-rotor brushless motor with a sealing structure. Background Art

[0002] An inner-rotor brushless motor is a type of motor that can provide stable power, output high efficiency and high power density, and is not affected by the external environment. It is an efficient drive solution. Its structure consists of a stator, a rotor, a drive board, and an external housing. Among them, the rotor adopts an inner-rotor structure, and permanent magnets are installed on the rotor, while the stator is composed of electromagnets with windings. In terms of the working principle, the inner-rotor brushless motor adopts electronic commutation technology, and a rotating magnetic field is generated by the windings installed on electromagnets with different polarities. When current passes through the windings of different phases, the generated magnetic field will interact with the magnets, thereby driving the rotor to rotate. Since the rotor is an inner-rotating structure, there is no need to adopt a mechanical contact commutation device, thus avoiding problems such as contact wear and electric sparks.

[0003] The inner-rotor brushless motor needs to cope with a complex working environment. There are important components such as magnets, drive boards, and windings inside the inner-rotor brushless motor that need to be protected. Therefore, the inner-rotor brushless motor needs to have a relatively high protection level. Currently, the conventional sealing structures mainly include:

[0004] At the wire outlet position, potting glue is used to bond and seal the wires of the motor and the end cover to form an isolated closed structure. The current problem with this structure is that if two-component glue is used, it is necessary to meet the curing and hardness requirements to meet the sealing requirements. Generally, the glue that meets the sealing requirements has the defect of insufficient durability. After oxidation and high-temperature durability, the colloid is prone to powdering, and the whole colloid detaches from the bonding surface, resulting in seal failure. If one-component glue is used, since one-component glue needs to absorb moisture in the air for curing, potting and curing become a problem. Potting in a sealed structure is likely to cause the colloid to not fully cure for several days or even dozens of days.

[0005] The installation surface between the motor housing and the end cover is sealed with a sealing ring. The sealing with a sealing ring has high requirements for the machining accuracy of the sealing surfaces of the components. The sealing ring mostly uses rubber material, and rubber parts have a fatigue life. When the inner-rotor brushless motor is working, the temperature of the housing is relatively high, which will accelerate the aging of the rubber parts, resulting in a decrease in the sealing elasticity of the sealing ring after a certain period of use, and further affecting the sealing performance of the product, leading to problems such as seal failure and product damage.

[0006] Therefore, we propose an inner-rotor brushless motor with a sealing structure. Summary of the Invention

[0007] To solve the technical problem of the poor performance of the existing sealing structure of motors, the present utility model provides an inner-rotor brushless motor with a sealing structure.

[0008] The present utility model is realized by the following technical solutions: An inner-rotor brushless motor with a sealing structure, including a motor housing and a motor end cover. A stator assembly is installed inside the motor housing. A driving board is installed on the skeleton support of the stator assembly. The motor end cover is clamped on the motor housing through the terminals of the driving board. An outgoing line sealing plug is installed on the motor end cover. A sealing cover plate is installed on the outgoing line sealing plug. The mounting posts on the sealing cover plate are installed on the motor end cover. A sealing gasket is installed at the gap position between the driving board and the motor end cover. The sealing cover plate, the outgoing line sealing plug, the sealing gasket, the motor end cover, and the motor housing form two sets of sealing structures, namely the sealing structure at the outgoing line position of the motor and the sealing structure at the assembly position of the motor housing.

[0009] The sealing at the outgoing line position includes the sealing cover plate, the outgoing line sealing plug, the sealing gasket, and the motor end cover. The sealing gasket passes through the welding terminals of the driving board and fits inside the motor end cover to block the hole position of the motor end cover for preliminary sealing, preventing the potting glue from entering the motor interior. The potting glue only forms a colloidal sealing structure in the internal space formed by the outgoing line sealing plug, the sealing cover plate, and the motor end cover to achieve the sealing effect.

[0010] As a further improvement of the above solution, the sealing cover plate, the outgoing line sealing plug, the sealing gasket, and the motor end cover use sealing glue to form the sealing effect at the outgoing line position.

[0011] As a further improvement of the above solution, the motor end cover and the motor housing use sealing glue to form a sealing structure.

[0012] As a further improvement of the above solution, the motor end cover and the motor housing are closely fitted, and three seals are formed through the combined action of the glue injection groove, the overflow glue groove, and the sealing glue.

[0013] As a further improvement of the above solution, a thin film with a small aperture is provided in the outgoing line hole of the outgoing line sealing plug.

[0014] The outlet position is sealed with a one-component silicone rubber for potting. The one-component silicone rubber has excellent end-face adhesion and anti-aging performance. Also, because the rubber is relatively soft, when the brushless motor is subjected to thermal and cold shocks, the silicone rubber can provide sufficient space for thermal expansion and contraction without peeling, which provides very good support for the sealing stability of the inner-rotor brushless motor in terms of high and low temperature tolerance and product durability. The curing condition of the one-component silicone rubber is to absorb moisture in the air, and the externally enclosed structure will seriously block the entry of moisture into the colloid. The sealing cover plate is a top-open structure, and a dense network structure is added in the open area of the sealing cover plate. The dense network structure of the sealing cover plate can provide sufficient support for the colloid, prevent the colloid from directly overflowing from the open area during potting, and can better fill the internal space of the sealing structure. The network structure can make the appearance of the colloid in the open area of the sealing cover plate more flat and beautiful.

[0015] In the top-open area of the sealing cover plate, after adding a dense network structure, it can still provide a good contact area between the colloid and the air. The colloid has sufficient air contact area, which can enable the colloid to better absorb moisture in the air, greatly reducing the curing time of the one-component silicone rubber in this structure. The one-component silicone rubber can be used as the sealing glue at the outlet seal, meeting the product sealing requirements and also meeting the production process requirements.

[0016] The outlet seal plug has a total of five hole positions for the outlet holes, which are used for the motor cable to pass through. To avoid the situation that the cable is difficult to install due to too tight hole position fit or glue overflow during potting due to too loose hole position fit, the inner diameter of the hole position of the outlet seal plug should match the cable specification.

[0017] The inner-rotor brushless motor has five wires. Three of them are signal wires, namely the PWM control wire, the feedback wire, and the CAN wire. The three signal wires are relatively thin and correspond to three small holes in the outlet seal plug, and the inner diameter of the hole position is 2.5 mm. Two of them are power wires, which are connected to the positive and negative poles of the power supply respectively. The positive and negative power wires have a large current and a relatively thick wire diameter specification, corresponding to two large holes in the outlet seal plug. The inner diameter of the two large holes is 4.5 mm, and a 10AWG power wire can be used. Some models need to use a 12AWG wire. To improve the versatility of the parts, a 1-mm-thick film with a diameter of 3.3 is added inside the two large holes. Through the film structure, products with two wire diameters can be used at the same time. When using a 10AWG wire, because the wire diameter exceeds the inner diameter of the film, the inner diameter of the film will be deformed when threading the wire, enabling the thick wire to also pass through the outlet seal plug. When using a 12AWG wire, the wire diameter matches the inner diameter of the film, and the film can provide a certain degree of sealing, keeping the colloid inside the structure and not overflowing during potting.

[0018] The sealing structure at the motor housing assembly position is composed of the glue application groove of the motor end cover, the glue overflow groove of the motor end cover, and the glue overflow groove of the motor housing.

[0019] The glue overflow groove on the motor end cover and the glue overflow groove on the motor housing are corresponding structures, and after installation, the two can form a complete glue groove.

[0020] The glue injection groove on the motor end cover is filled with glue by using a one-component silicone rubber operation. The glue is higher than the original right-angle line of the glue injection groove. After the motor end cover is installed, the two are pressed against each other to squeeze the excess glue into the glue overflow groove, forming a three-layer seal. The three seals formed by this structure are the glue seal of the glue injection groove, the seal formed by the glue film pressed by the mating end faces of the motor end cover and the motor housing, and the seal formed after the glue overflows into the glue overflow groove after extrusion. This structure forms three seals at the installation position of the motor housing and the motor end cover, which can not only ensure the effectiveness of the sealing structure at the joint of the motor housing and the motor end cover, but also provide good durability and resistance to thermal and cold shocks.

[0021] As a further improvement of the above solution, the sealing cover plate has a structure with an open top.

[0022] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0023] The present utility model enhances the sealing performance of the inner rotor brushless motor at the motor lead-out position and the joint position of the motor housing and the motor end cover. While ensuring the sealing performance, it can also make the sealing of the product reliable under harsh conditions such as high temperature, durability, and thermal and cold shocks, and solve the sealing problem of the inner rotor brushless motor.

[0024] The present utility model uses a one-component silicone rubber for the sealing of the brushless motor. It not only has a lower cost, but also has simpler potting conditions. There is no need for mixing glue and heating potting, and the process is simple and easy to implement. It can also avoid the uncuring problem caused by uneven mixing ratio of the two-component glue; the curing method is simpler: room temperature moisture curing, fast surface drying, and there is no need to use a drying tunnel for heating. At the same time, due to the characteristics of the glue after curing, it not only greatly improves the sealing performance of the brushless motor, but also enables the brushless motor to provide good sealing effects throughout the product life cycle, ensuring the product protection level. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is an exploded view of an inner rotor brushless motor with a sealing structure;

[0026] Figure 2 is a top view structure schematic diagram of an inner rotor brushless motor with a sealing structure;

[0027] Figure 3 is a cross-sectional view of an inner rotor brushless motor with a sealing structure;

[0028] Figure 4 is a schematic diagram of the sealing cover plate in an inner rotor brushless motor with a sealing structure;

[0029] Figure 5 Partial schematic diagram of the gap between the motor end cover and the motor housing in an inner rotor brushless motor with a sealing structure.

[0030] Main symbol description:

[0031] Sealing cover plate; 2. Lead-out line sealing plug; 3. Sealing gasket; 4. Motor end cover; 5. Motor housing; 6. Stator assembly; 7. Driving board. Specific implementation mode

[0032] Next, in combination with the drawings and specific implementation modes, the present utility model will be further described. It should be noted that on the premise of no conflict, the following-described embodiments or technical features can be combined arbitrarily to form new embodiments.

[0033] Refer to Figures 1-5 , an inner rotor brushless motor with a sealing structure in this embodiment includes a motor housing 5 and a motor end cover 4. A stator assembly 6 is installed inside the motor housing 5, and a driving board 7 is installed on the skeleton support of the stator assembly 6 and locked with screws. The motor end cover 4 is clamped on the motor housing 5 through the terminals of the driving board 7. A lead-out line sealing plug 2 is installed on the motor end cover 4, a sealing cover plate 1 is installed on the lead-out line sealing plug 2, the mounting posts on the sealing cover plate 1 are installed on the motor end cover 4, and a sealing gasket 3 is installed at the gap position between the driving board 7 and the motor end cover 4.

[0034] The sealing cover plate 1, the lead-out line sealing plug 2, the sealing gasket 3 and the motor end cover 4 use sealant to form a sealing effect at the lead-out line position.

[0035] The motor end cover 4 and the motor housing 5 use sealant to form a sealing structure.

[0036] The motor end cover 4 and the motor housing 5 are closely fitted, and three seals are formed through the combined action of the caulking groove, the overflow groove and the sealant.

[0037] A thin film with a small aperture is provided in the lead-out hole of the lead-out line sealing plug 2.

[0038] The sealing cover plate 1 has a structure with an open top.

[0039] Working principle: The gap between the motor housing 5 and the motor end cover 4 is a caulking groove, that is Figure 5 the semi-arc structure position. The sealant is evenly filled in the caulking groove. The inner and outer diameters of the motor end cover 4 and the motor housing 5 are closely fitted. When the two end faces are attached, the end face of the motor housing 5 squeezes the raised glue in the caulking groove and pushes it into the overflow groove on one side of the caulking groove. The overflow groove is Figure 5The position of the rectangular structure. The glue overflow groove has upper and lower parts. One part is the groove of the motor housing 5, and the other part is the groove of the motor end cover 4. After combination, a complete glue overflow groove is formed. When the glue injection groove and the glue overflow groove are filled with sealant, the first seal, the second seal, and the third seal are formed. The three seals greatly improve the sealing performance at the joint of the motor housing 5 and the motor end cover 4.

[0040] Sealing at the wire outlet of the inner rotor brushless motor. At Figure 4 As shown, inside the motor end cover is a gasket 3. The inner wall of the raised structure of the gasket 3 is in interference fit with the terminals of the drive board 7, closely fitting the drive board terminals with the gasket. Then, the surface of the gasket 3 is attached to the inner wall of the motor end cover 4, and the outer wall of the raised part of the gasket 3 is closely attached to the inner wall of the square groove of the motor end cover 4. The gasket 3 fills the gap between the drive board 7 and the motor end cover 4, forming a preliminary sealing structure to prevent potting glue from flowing into the interior of the motor product and causing abnormalities.

[0041] For the five terminals of the drive board 7, three small terminals are welded with signal function wires, and two large terminals are welded with the positive and negative power supply wires. The extended wire of the wire outlet seal plug 2 is inserted into the terminal position, and the wire outlet seal plug 2 is installed on the motor end cover 4. The two holes for the power supply wires of the wire outlet seal plug 2 have small-aperture films, which can match two wire specifications of 12AWG and 10AWG. When using a thin wire, the small-aperture film fits the outer diameter of the power supply wire to provide sealing; when using a thick wire, the wire diameter stretches the film to form an interference fit to provide sealing. The wire outlet seal plug 2 can provide a sealing structure for the motor wire outlet. Finally, the three mounting posts of the sealing cover plate 1 are installed in the mounting groove of the motor end cover 4 by interference fit. The extrusion between the sealing cover plate 1 and the wire outlet seal plug 2, and the close fit between the groove of the sealing cover plate 1 and the raised rib position of the motor end cover 4 form the internal space for the potting glue. After the cooperation of each structure is completed, potting glue is potted through the potting port of the sealing cover plate 1. The colloid fills the internal space after passing through the potting port. There is an opening area at the top of the sealing cover plate 1, and there is a dense mesh structure in the opening area. The mesh structure can exhaust air during potting, and the dense mesh structure can prevent the potting glue from overflowing. After the colloid cures, it can also serve as the appearance surface of the opening area. The mesh structure can ensure that there is enough contact surface between the colloid and the air, and can provide enough water vapor for the curing of one-component silicone, ensuring the curing conditions. By constructing the internal structure area of the potting glue and the external curing conditions inside, an effective sealing barrier is established at the wire outlet position to ensure the sealing performance of the product.

[0042] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A brushless inner rotor motor with a sealing structure, comprising a motor housing and a motor end cover, characterized in that, The stator assembly is installed inside the motor housing. A driving plate is installed on the skeleton support of the stator assembly. The motor end cover is clamped on the motor housing through the terminals of the driving plate. An outgoing line sealing plug is installed on the motor end cover. A sealing cover plate is installed on the outgoing line sealing plug. The mounting posts on the sealing cover plate are installed on the motor end cover. A sealing gasket is installed at the gap position between the driving plate and the motor end cover.

2. The brushless inner-rotor motor with a sealing structure according to claim 1, wherein The sealing cover plate, the outgoing line sealing plug, the sealing gasket and the motor end cover use sealant to form a sealing effect at the outgoing line position.

3. The brushless inner rotor motor with a sealing structure according to claim 1, wherein The motor end cover and the motor housing use sealant to form a sealing structure.

4. A brushless inner rotor motor with a sealing structure as claimed in claim 1, characterized in that, The motor end cover and the motor housing are closely fitted, and three seals are formed through the combined action of the caulking groove, the overflow groove and the sealant.

5. The brushless inner rotor motor with a sealing structure according to claim 1, characterized in that, A thin film with a small aperture is provided in the outgoing line hole of the outgoing line sealing plug.

6. The brushless inner-rotor motor with a sealing structure according to claim 1, characterized in that The sealing cover plate has a structure with an open top.

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