A motor without a rear cover

Abstract

This utility model discloses a rear cover-less motor, including a housing, a front cover, a rotor assembly, a stator assembly, a bearing assembly, and a heat dissipation assembly. The housing is a cylindrical structure with one open end and the other closed. The front cover is installed at the open end, and the bearing assembly is installed at the closed end. The rotor assembly's shaft is supported at both ends by the bearing assembly and the sealed bearings of the front cover, respectively. The stator assembly is fixed to the inner wall of the housing and located on the outer periphery of the rotor assembly. The heat dissipation assembly guides airflow for heat dissipation as the shaft rotates. This motor simplifies the structure through the rear cover-less design, improves heat dissipation efficiency by combining spiral gradient heat dissipation ribs and corrugated heat dissipation fins, enhances sealing performance with double-lip sealed bearings and elastic sealing gaskets, and suppresses rotor vibration with elastic expansion sleeves. It is suitable for the integration requirements of lightweight equipment and features a compact structure and stable performance.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to a structural innovation of a motor without a rear end cover. It focuses on the compactness, lightweight, efficient heat dissipation, and high reliability design of the motor, and is suitable for application scenarios with stringent requirements for installation space and operational stability, such as industrial robots, new energy equipment, and precision automated production lines. It belongs to the direction of structural optimization and performance enhancement of mechatronics equipment. Background Technology

[0002] Traditional motors typically use front and rear covers to axially position and radially support the rotor assembly to ensure stable operation.

[0003] However, this structure has the following problems: the presence of the rear end cover increases the axial dimension of the motor, making it difficult to meet the compact layout requirements in scenarios with limited installation space, such as industrial robot joints and drones; the connection surface between the rear end cover and the housing forms a "thermal bridge," hindering the dissipation of heat inside the motor and affecting the motor's heat dissipation efficiency and operational stability; the processing and assembly of the rear end cover increases the complexity of the motor's manufacturing process and manufacturing cost, while also increasing the overall weight of the motor, which is not conducive to lightweight design; the bearing sealing structure between the rear end cover and the shaft is complex, and after long-term use, the seal is prone to failure, leading to the intrusion of dust, moisture, etc., affecting the service life of the bearing and the reliability of the motor.

[0004] Therefore, it is necessary to design a motor without a rear end cover to solve the problems mentioned above. Utility Model Content

[0005] To address the problems of traditional motors with rear end covers, such as difficulty in fitting into compact spaces, low heat dissipation efficiency, insufficient reliability, and limited lightweighting, this utility model designs a motor without a rear end cover. By eliminating the rear end cover and optimizing the structure of components such as the housing, rotor, stator, and heat dissipation, the axial dimensions of the motor are reduced, the weight is decreased, and the heat dissipation performance, operational stability, and environmental adaptability are improved, meeting the stringent application requirements of motors in industrial robots, new energy equipment, and other fields.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] This motor without a rear end cover is composed of a housing, a front end cover, a rotor assembly, a stator assembly, a bearing assembly, and a heat dissipation assembly. Each component is designed with the goal of "compactness, efficient heat dissipation, and high reliability" in mind.

[0008] Furthermore, the casing is a cylindrical structure with one end open and the other end closed. The inner wall is equipped with spiral gradient heat dissipation ribs, which, together with the corrugated heat dissipation fins on the outer wall, form a directional heat dissipation channel. The bearing assembly is integrated in the center of the inner side of the closed end, replacing the support function of the traditional rear end cover. The casing is made of aluminum alloy extrusion molding + hard anodizing process, which ensures strength while achieving lightweight, and is suitable for installation in compact spaces.

[0009] Furthermore, the front cover is installed at the opening end of the housing, with a double-lip sealed bearing at the center, and the edges are connected to the housing through a connecting seat and elastic sealing gasket to fill the installation gap, enhance the sealing performance of the opening end, and prevent external dust and moisture from entering.

[0010] Furthermore, the rotor assembly includes a shaft, an armature core, and a permanent magnet. The permanent magnet is a radially magnetized neodymium iron boron magnet, which is interference-fitted with the armature core. The mating surfaces of the shaft and the armature core are provided with keyways and stainless steel elastic expansion sleeves. The elastic deformation of the expansion sleeves adaptively compensates for thermal expansion and contraction gaps, suppresses rotor vibration during high-speed operation, and ensures dynamic balance.

[0011] Furthermore, the stator assembly consists of a stator core and stator windings. The stator core has a ceramic tube composite insulating bushing embedded in the winding slot. The winding ends are provided with epoxy glass cloth insulating end plates. Polyimide insulating pads are added between the end plates and the stator core teeth to construct a triple insulation protection of "bushing + end plate + pads", which improves the insulation strength of the winding ends and reduces the risk of creepage.

[0012] Furthermore, the bearing assembly includes a bearing housing, a deep groove ball bearing, and a flexible retaining ring. The bearing housing is fixed to the closed end of the housing, the deep groove ball bearing is installed inside the housing, one end of the shaft is interference-fitted with the inner ring of the bearing, and the flexible retaining ring axially positions the bearing. A skeleton oil seal is provided between the bearing housing and the shaft, which, together with the compact structure of the housing, replaces the sealing and support function of the traditional rear end cover and simplifies the axial layout of the motor.

[0013] Furthermore, the heat dissipation component is a variable cross-section airfoil cooling fan, fixed on the side of the rotating shaft near the closed end of the housing, and rotates synchronously with the rotating shaft. A horn-shaped air guide is provided at the corresponding position of the closed end of the housing to guide the airflow through "air guide → closed end of housing → heat dissipation ribs → heat dissipation fins", thereby enhancing the internal heat dissipation of the motor and improving the heat exchange efficiency.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] This invention, through the design of a motor without a rear end cover, achieves the following effects: 1. Eliminating the rear end cover reduces the axial dimension of the motor, and the lightweight process of the housing and front end cover reduces the overall weight, making it suitable for compact installation scenarios such as industrial robot joints and drones; 2. Spiral heat dissipation ribs, corrugated fins, air guides, and cooling fans work together to construct a three-stage heat dissipation channel, improving heat exchange efficiency, effectively reducing winding temperature rise, delaying insulation aging, and extending motor life; 3. Multiple sealing structures (double-lip bearings, elastic sealing gaskets, and skeleton oil seals) enhance the motor's protection level; elastic expansion sleeves suppress rotor vibration, ensuring high-speed operation stability and reducing the risk of failure; 4. The hard anodizing treatment of the aluminum alloy housing and the silicone rubber / hydrogenated nitrile rubber seals enable the motor to adapt to harsh environments such as humidity, dust, and salt spray, broadening its application scenarios. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall three-dimensional structure of this utility model;

[0017] Figure 2 This utility model Figure 1 Front view structural diagram;

[0018] Figure 3 This is a three-dimensional structural diagram of the disassembled motor of this utility model;

[0019] Figure 4 This utility model Figure 3 A schematic diagram of the main structure.

[0020] In the diagram: 1. Housing; 2. Front cover; 3. Rotor assembly; 4. Stator assembly; 5. Heat dissipation assembly; 11. Heat dissipation ribs; 12. Heat dissipation fins; 13. Bearing assembly; 21. Connecting seat; 31. Shaft. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0022] To facilitate understanding of this utility model, a more comprehensive description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are provided. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0023] Example 1

[0024] Please see Figure 1 This embodiment provides a motor without a rear end cover, including:

[0025] The housing 1 is a cylindrical structure with one end open and the other end closed. Its inner wall is provided with axial heat dissipation ribs 11, its outer wall is wrapped with heat dissipation fins 12, and a bearing assembly 13 is provided at the center of the inner side of the closed end.

[0026] The front cover 2 is installed at the open end of the housing 1. A shaft mounting hole is opened in the center, and a sealed bearing is installed in the hole. A connecting seat 21 is provided at the edge of the front cover 2. The connecting seat 21 is fixedly connected to the connecting seat 21 at the open end of the housing 1 by bolts.

[0027] The rotor assembly 3 includes a shaft 31, an armature core, and permanent magnets. The armature core is fixedly sleeved on the outside of the shaft 31, and the permanent magnets are evenly distributed around the outer periphery of the armature core. One end of the shaft 31 is installed in the corresponding hole at the closed end of the housing 1 via the bearing assembly 13, and the other end passes through the bearing mounting hole of the front cover 2 and is supported by a sealed bearing. The stator assembly 4 includes a stator core and a stator winding. The stator core is fixedly installed on the inner side wall of the housing 1 and is located on the outer periphery of the rotor assembly 3. The teeth of the stator core have slots for winding, and the stator winding is wound inside the slots.

[0028] The bearing assembly 13 includes a bearing housing, a deep groove ball bearing, and a retaining ring. The bearing housing is fixed to the closed end of the housing 1. The deep groove ball bearing is installed inside the bearing housing. One end of the shaft 31 is interference-fitted with the inner ring of the deep groove ball bearing. The retaining ring is installed on the shaft 31 and is located on the outside of the deep groove ball bearing. A skeleton oil seal is provided between the bearing housing and the shaft 31.

[0029] The heat dissipation component 5 is specifically a cooling fan. The cooling fan is fixedly installed on the rotating shaft 31 on one side of the closed end of the casing 1 and rotates synchronously with the rotating shaft 31 to guide airflow for heat dissipation.

[0030] Example 2

[0031] Please see Figure 1 , Figure 2 as well as Figure 3 Based on Embodiment 1, this embodiment further defines the heat dissipation ribs 11 as a spirally tapered distribution structure, which extends from the closed end of the housing 1 to the open end, and the spacing between adjacent ribs gradually decreases along the axial direction. The heat dissipation fins 12 are corrugated fins, and micro-turbulence grooves are opened on the surface of the fins. The micro-turbulence grooves are adapted to the spiral direction of the heat dissipation ribs 11, thereby enhancing the heat exchange efficiency between the inside and outside of the motor by enhancing airflow turbulence.

[0032] Example 3

[0033] Please see Figure 2 as well as Figure 4Based on Embodiment 1, this embodiment further specifies that the sealing bearing of the front cover 2 is a double-lip sealing bearing, including an inner dustproof lip and an outer waterproof lip. The lip material is hydrogenated nitrile rubber. An elastic sealing gasket is provided between the front cover 2 and the connecting seat 21 of the housing 1. The elastic sealing gasket is made of silicone rubber to fill the installation gap of the connecting seat 21 and enhance the sealing performance of the opening end of the housing 1.

[0034] Example 4

[0035] Please see Figure 3 as well as Figure 4 Based on Embodiment 1, this embodiment further specifies that the permanent magnet of the rotor assembly 3 is a radially magnetized neodymium iron boron magnet, the magnet and the armature core are fitted with an interference fit, a keyway is opened on the mating surface of the rotating shaft 31 and the armature core, and an elastic expansion sleeve is installed in the keyway. The elastic expansion sleeve is made of stainless steel. Through the elastic deformation of the expansion sleeve, the thermal expansion and contraction gap between the rotating shaft 31 and the armature core is adaptively compensated, and the rotor vibration is suppressed when the motor is running at high speed.

[0036] Example 5

[0037] Please see Figure 3 as well as Figure 4 Based on Example 1, this embodiment further specifies that a composite insulating bushing is provided in the stator core winding slot of the stator assembly 4. The composite insulating bushing is a ceramic tube, and the bushing is interference-fitted with the winding slot. An insulating end plate is provided at the end of the stator winding of the stator assembly 4. The insulating end plate is an epoxy glass cloth board with a nano insulating coating on the surface. An insulating pad is provided between the insulating end plate and the teeth of the stator core. The insulating pad is made of polyimide, thereby improving the insulation strength at the end of the stator winding and reducing the risk of creepage at the end of the winding.

[0038] Example 6

[0039] Please see Figure 3 Based on embodiment 1, this embodiment further defines the cooling fan of the heat dissipation component 5 as a variable cross-section airfoil fan. The thickness of the fan blades gradually decreases from the blade root to the blade tip. Spiral turbulence grooves are opened on the blade surface. A guide shroud is set at the closed end of the housing 1 corresponding to the position of the cooling fan. The guide shroud has a horn-shaped structure. A guide grille is set at the air inlet. The air outlet is attached to the heat dissipation fins 12 of the housing 1. Through the forced air cooling of the cooling fan, the airflow flows along "guide shroud → closed end of housing → heat dissipation ribs → heat dissipation fins".

[0040] Example 7

[0041] Please see Figure 1Based on Example 1, this embodiment further specifies that the housing 1 is made of aluminum alloy extrusion molding and hard anodizing process, and the front cover 2 is made of magnesium alloy die casting structure. Under the premise of ensuring strength, the overall weight of the motor is reduced, which is suitable for the integration requirements of lightweight equipment.

[0042] The working process of this utility model is as follows: When using this motor without a rear end cover, the housing 1 serves as the basic structure. A bearing assembly 13 is installed at the center of the inner side of the closed end. The open end is bolted to the connecting seat 21 of the front end cover 2, and an elastic sealing gasket is provided between the two to enhance the seal. The armature core of the rotor assembly 3 is fixedly sleeved on the rotating shaft 31. The permanent magnets are evenly distributed on the outer periphery of the armature core. One end of the rotating shaft 31 is installed on the closed end of the housing 1 via the bearing assembly 13, and the other end passes through the sealed bearing of the front end cover 2. The stator core of the stator assembly 4 is fixedly installed on the inner wall of the housing 1 and located on the outer periphery of the rotor assembly 3. The stator winding is wound in the slot of the stator core tooth.

[0043] After the motor starts, the rotor assembly 3's shaft 31 rotates, driving the permanent magnet to move synchronously, interacting with the stator windings of the stator assembly 4 to generate driving force; the rotation of the shaft 31 simultaneously drives the cooling fan of the heat dissipation assembly 5 to operate, and the airflow enters through the air guide shroud, flowing along the closed end of the housing 1, the heat dissipation ribs 11, and the heat dissipation fins 12, enhancing the internal and external heat exchange through the heat dissipation ribs 11 and the heat dissipation fins 12; the double-lip sealed bearing of the front cover 2 and the elastic sealing gasket between the housing 1 and the front cover 2 prevent external impurities from entering, ensuring internal cleanliness; the elastic expansion sleeve of the rotor assembly 3 compensates for thermal expansion and contraction gaps, suppressing vibration; the composite insulating bushing, insulating end plate, and insulating pad of the stator assembly 4 improve insulation strength and reduce creepage risk; the housing 1 adopts aluminum alloy extrusion molding and hard anodizing process, and the front cover 2 is a magnesium alloy die-cast structure, achieving lightweight while ensuring strength, adapting to the integration requirements of related equipment.

[0044] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A motor without a rear cover, characterized by, include: The casing (1) is a cylindrical structure with one end open and the other end closed. Its inner wall is provided with axial heat dissipation ribs (11), and its outer wall is wrapped with heat dissipation fins (12). A bearing assembly (13) is provided at the center of the inner side of the closed end. The front cover (2) is installed at the opening end of the housing (1), with a shaft mounting hole in the center and a sealed bearing installed in the hole. A connecting seat (21) is provided at the edge of the front cover (2), and the connecting seat (21) is fixedly connected to the same connecting seat (21) at the opening end of the housing (1) by bolts. The rotor assembly (3) includes a rotating shaft (31), an armature core and permanent magnets. The armature core is fixedly sleeved on the outside of the rotating shaft (31). The permanent magnets are evenly distributed on the outer periphery of the armature core. One end of the rotating shaft (31) is installed in the corresponding hole at the closed end of the housing (1) via a bearing assembly (13), and the other end passes through the bearing mounting hole of the front cover (2) and is supported by a sealed bearing. The stator assembly (4) includes a stator core and a stator winding. The stator core is fixed to the inner wall of the housing (1) and located on the outer periphery of the rotor assembly (3). The teeth of the stator core have slots for winding, and the stator winding is wound inside the slots. The bearing assembly (13) includes a bearing housing, a deep groove ball bearing, and an elastic retaining ring. The bearing housing is fixed to the closed end of the housing (1). The deep groove ball bearing is installed inside the bearing housing. One end of the rotating shaft (31) is interference-fitted with the inner ring of the deep groove ball bearing. The elastic retaining ring is installed on the rotating shaft (31) and is located on the outside of the deep groove ball bearing. A skeleton oil seal is provided between the bearing housing and the rotating shaft (31). The heat dissipation component (5) is specifically a cooling fan. The cooling fan is fixedly installed on the rotating shaft (31) on one side of the closed end of the housing (1). It rotates synchronously with the rotating shaft (31) to guide airflow for heat dissipation.

2. The motor without a rear cover according to claim 1, characterized in that: The heat dissipation ribs (11) are spirally distributed structures that extend from the closed end to the open end of the housing (1), and the spacing between adjacent ribs gradually decreases along the axial direction. The heat dissipation fins (12) are corrugated fins with micro-turbulence grooves on the surface of the fins. The micro-turbulence grooves are adapted to the spiral direction of the heat dissipation ribs (11).

3. A motor without a rear end cover according to claim 1, characterized in that: The sealing bearing of the front cover (2) is a double-lip sealing bearing, including an inner dustproof lip and an outer waterproof lip. The lip material is hydrogenated nitrile rubber. An elastic sealing gasket is provided between the front cover (2) and the connecting seat (21) of the housing (1). The elastic sealing gasket is made of silicone rubber.

4. A motor without a rear end cover according to claim 1, characterized in that: The permanent magnet of the rotor assembly (3) is a radially magnetized neodymium iron boron magnet. The magnet and the armature core are fitted with an interference fit. The mating surface of the shaft (31) and the armature core is provided with a keyway. An elastic expansion sleeve is installed in the keyway. The elastic expansion sleeve is made of stainless steel.

5. A motor without a rear end cover according to claim 1, characterized in that: The stator core of the stator assembly (4) is provided with a composite insulating bushing, which is a ceramic tube and is interference-fitted with the bushing. The stator winding end of the stator assembly (4) is provided with an insulating end plate, which is an epoxy glass cloth board with a nano insulating coating on the surface. An insulating pad is provided between the insulating end plate and the teeth of the stator core, which is made of polyimide.

6. A motor without a rear end cover according to claim 1, characterized in that: The cooling fan of the heat dissipation component (5) is a variable cross-section airfoil fan. The thickness of the fan blades gradually decreases from the blade root to the blade tip. Spiral turbulence grooves are opened on the blade surface. A guide shroud is set at the closed end of the housing (1) corresponding to the position of the cooling fan. The guide shroud is a horn-shaped structure. A guide grille is set at the air inlet. The air outlet is attached to the heat dissipation fins (12) of the housing (1).

7. A motor without a rear end cover according to claim 1, characterized in that: The housing (1) is made of aluminum alloy by extrusion molding and hard anodizing, and the front cover (2) is made of magnesium alloy by die casting.

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