Electric tool brushless motor

Abstract

The utility model discloses a kind of electric tool class brushless motor, including rotor core and motor shaft, the rotor core is excessively matched with motor shaft, the magnet is clamped in the rotor core, the both ends of the rotor core are provided with plastic cover and fan blade respectively, the opposite side of plastic cover and fan blade is fixedly installed with three triangular columns, the both ends of the rotor core are provided with three triangular grooves;Through the setting of triangular column, triangular groove, fan blade, rotor core, plastic cover and motor shaft, triangular column is inserted into the triangular groove of rotor core respectively, then in the rotation process of rotor core, drive fan blade to rotate, the heat on stator assembly enameled wire is blown out, temperature is reduced, to prevent temperature from being too high and burning enameled wire, to generate function failure;The end face of plastic cover and the circular ring feature of fan blade can resist magnet, prevent magnet from being thrown out from the hole of rotor core.

Description

Technical Field

[0001] This utility model relates to the field of brushless motor technology, specifically a brushless motor for power tools. Background Technology

[0002] Brushless motors for power tools are typically of a split structure, consisting of two independent stator and rotor assemblies; the stator and rotor assemblies are fixed and clamped together by the structural features of the machine itself.

[0003] Sometimes multiple platform tools share a single brushless motor. If the motor is a separate unit, then all platform tools need to be designed to work with the stator and rotor components. This increases the complexity of the platform tool parts, as well as the corresponding mold costs and unit price. Utility Model Content

[0004] The purpose of this utility model is to provide a brushless motor for power tools to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a brushless motor for power tools, comprising a rotor core and a motor shaft, wherein the rotor core and the motor shaft are interference-fitted, a magnet is snapped into the rotor core, a plastic cover and a fan blade are respectively provided at both ends of the rotor core, three triangular prisms are fixedly installed on opposite sides of the plastic cover and the fan blade, three triangular slots are provided at both ends of the rotor core, the plastic cover and the fan blade are respectively snapped into the two ends of the rotor core through the three triangular prisms and the three triangular slots, the plastic cover and the motor shaft are interference-fitted, a ball bearing is fixedly connected to the outer wall of the motor shaft, the outer wall of the ball bearing is fixedly connected to the plastic cover, and a stator assembly is provided on the outer wall of the rotor core.

[0006] Preferably, the stator assembly includes a front wire frame and a rear wire frame, a plurality of iron ferrites are fixedly connected between the front wire frame and the rear wire frame, the rotor core is located between the plurality of iron ferrites, and the outer wall of the iron ferrites is wound with enameled wire.

[0007] Preferably, one end of the enameled wire is fixedly connected to a terminal, and a Hall plate is fixedly connected to the side wall of the rear wire frame away from the front wire frame, with one end of the terminal fixedly connected to the Hall plate.

[0008] Preferably, the rear cable tray is connected to the side wall of the plastic cover, and the front cable tray is connected to the side wall of the fan blade.

[0009] Preferably, the rotor core is provided with a front cover and a rear cover at both ends, the front cover is installed on one side of the stator assembly, the rear cover is installed on the other side of the stator assembly, and the front cover and the rear cover are threadedly connected by screws, and a wave-shaped gasket is provided between the motor shaft and the rear cover.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows: by setting up triangular pillars, triangular slots, fan blades, rotor cores, plastic covers, and motor shafts, the triangular pillars are respectively inserted into the triangular slots of the rotor cores. During the rotation of the rotor cores, the fan blades are driven to rotate, which dissipates the heat on the enameled wires of the stator assembly, reducing the temperature and preventing the enameled wires from burning due to excessive temperature, thus causing functional failure. At the same time, the end face of the plastic cover and the annular features of the fan blades can resist the magnets, preventing the magnets from being thrown out of the inner hole of the rotor cores. Attached Figure Description Figure 1 This is a three-dimensional structural diagram of the present invention.

[0011] Figure 2 This is a schematic diagram of the partially disassembled three-dimensional structure of this utility model.

[0012] Figure 3 This is a three-dimensional structural diagram of the screw, back cover, and front cover of this utility model.

[0013] Figure 4 This is a front view cross-sectional three-dimensional structural diagram of the stator assembly of this utility model.

[0014] Figure 5 This is a front view cross-sectional three-dimensional structural diagram of the rotor assembly of this utility model.

[0015] Figure 6 This is a partial front view cross-sectional three-dimensional structural schematic diagram of the present invention.

[0016] Figure 7 This is a three-dimensional structural diagram of the fan blade of this utility model from another perspective.

[0017] In the diagram: 1. Front wire frame; 2. Iron chip; 3. Enameled wire; 4. Rear wire frame; 5. Terminal; 6. Hall plate; 7. Ball bearing; 8. Plastic cover; 9. Rotor core; 10. Magnet; 11. Fan blade; 12. Motor shaft; 13. Front cover; 14. Waveform gasket; 15. Rear cover; 16. Screw. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] Please see Figures 1-7This utility model provides a technical solution: a brushless motor for power tools, including a rotor core 9 and a motor shaft 12. The rotor core 9 and the motor shaft 12 are interference-fitted. A magnet 10 is snapped into the rotor core 9. Plastic covers 8 and fan blades 11 are respectively provided at both ends of the rotor core 9. Three triangular pillars are fixedly installed on the opposite sides of the plastic covers 8 and the fan blades 11. Three triangular slots are opened at both ends of the rotor core 9. The plastic covers 8 and the fan blades 11 are respectively snapped into the two ends of the rotor core 9 through the three triangular pillars and the three triangular slots. The plastic covers 8 and the motor shaft 12 are interference-fitted. A ball bearing 7 is fixedly connected to the outer side of the motor shaft 12. The outer wall of the ball bearing 7 is fixedly connected to the plastic cover 8. The inner side of the ball bearing 7 is fixedly connected to the motor shaft 12. The outer wall of the ball bearing 7 is fixedly connected to the plastic cover 8. A stator assembly is provided on the outer wall of the rotor core 9.

[0020] The working principle of the above technical solution is as follows: The rotor core 9 rotates, driving the motor shaft 12 to rotate. Due to the interference fit between the inner hole of the fan blade 11 and the shaft rib of the motor shaft 12, axial stability is ensured. The fan blade 11 has a triangular prism feature, which is directly inserted into the triangular slot of the rotor core 9 to drive the fan blade 11 to rotate. The annular feature of the fan blade 11 can abut against the magnet 10 to prevent the magnet 10 from being thrown out of the inner hole of the rotor core 9. Similarly, the plastic cover 8 acts as a metal balance block. The plastic cover 8 also has an interference fit with the shaft rib of the motor shaft 12 to ensure axial stability. The plastic cover 8 has three triangular prism features, which are directly inserted into the triangular slot of the rotor core 9 to drive the fan blade 11 to rotate. At the same time, the end face of the plastic cover 8 can abut against the magnet 10 to prevent the magnet 10 from being thrown out of the inner hole of the rotor core 9.

[0021] In another implementation scheme, such as Figure 4 As shown, the stator assembly includes a front wire frame 1 and a rear wire frame 4. Multiple iron chips 2 are fixedly connected between the front wire frame 1 and the rear wire frame 4. The rotor core 9 is located between the multiple iron chips 2. Enamelled wire 3 is wound around the outer wall of the iron chips 2. One end of the enamelled wire 3 is fixedly connected to a terminal 5. A Hall plate 6 is fixedly connected to the side wall of the rear wire frame 4 away from the front wire frame 1. One end of the terminal 5 is fixedly connected to the Hall plate 6. The rear wire frame 4 is connected to the side wall of the plastic cover 8. The front wire frame 1 is connected to the side wall of the fan blade 11.

[0022] When the enameled wire 3 is connected to the current through the terminal 5, it generates a stator magnetic field. The magnetic field interacts with the magnet 10 to drive the rotor core 9 to rotate. The rotor core 9 is fixedly connected to the motor shaft 12, thereby driving the motor shaft 12 to rotate. The terminal 5 indirectly determines the start-stop, speed and output torque of the motor shaft 12 by controlling the energization state of the enameled wire 3. It is the "control bridge" for the power output of the motor shaft 12.

[0023] In another implementation scheme, such as Figures 3-6As shown, the rotor core 9 has a front cover 13 and a rear cover 15 at both ends. The front cover 13 is installed on one side of the stator assembly, and the rear cover 15 is installed on the other side of the stator assembly. The front cover 13 and the rear cover 15 are connected by screws 16. A wave-shaped gasket 14 is provided between the motor shaft 12 and the rear cover 15.

[0024] The front cover 13 and the rear cover 15 have hollowed-out ventilation features, and both the rear cover 15 and the front cover 13 have three enameled wire positioning grooves that cooperate with the stator core positioning posts. One set of positioning features has positioning posts and positioning grooves that are larger than the other two sets, which is used to prevent mistaken identification. The stator core positioning posts have a central hole feature, which is used to fix and connect the front cover 13 and the rear cover 15 with three screws 16.

[0025] Working principle: When current is applied to the enameled wire 3 through terminal 5, a stator magnetic field is generated. The magnetic field interacts with the magnet 10, driving the rotor core 9 to rotate. The rotor core 9 is fixedly connected to the motor shaft 12, thereby driving the motor shaft 12 to rotate. Terminal 5 indirectly determines the start / stop, speed, and output torque of the motor shaft 12 by controlling the energization state of the enameled wire 3, serving as the "control bridge" for the power output of the motor shaft 12. The fan blade 11 has a triangular prism feature, which is directly inserted into the triangular slot of the rotor core 9 to drive the fan blade 11 to rotate. Furthermore, the annular feature of the fan blade 11 can resist the magnet 10, preventing... The magnet 10 is thrown out from the inner hole of the rotor core 9; similarly, the plastic cover 8 acts as a right metal balance block. The plastic cover 8 is also interference-fitted with the motor shaft 12 to ensure axial stability. The plastic cover 8 has three triangular prism features. The triangular prisms are directly inserted into the triangular slots of the rotor core 9 to drive the fan blade 11 to rotate. At the same time, the end face of the plastic cover 8 can abut against the magnet 10 to prevent the magnet 10 from being thrown out from the inner hole of the rotor core 9. When the fan blade 11 rotates with the rotor core 9, it blows away the heat on the enameled wire 3 of the stator assembly to reduce the temperature and prevent the enameled wire 3 from burning due to excessive temperature, thereby causing functional failure.

[0026] 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 brushless motor for power tools, comprising a rotor core (9) and a motor shaft (12), characterized in that: The rotor core (9) is interference-fitted with the motor shaft (12). A magnet (10) is snapped into the rotor core (9). A plastic cover (8) and a fan blade (11) are respectively provided at both ends of the rotor core (9). Three triangular pillars are fixedly installed on the opposite sides of the plastic cover (8) and the fan blade (11). Three triangular slots are opened at both ends of the rotor core (9). The plastic cover (8) and the fan blade (11) are respectively snapped into the two ends of the rotor core (9) through the three triangular pillars and the three triangular slots. The plastic cover (8) is interference-fitted with the motor shaft (12). A ball bearing (7) is fixedly connected to the outside of the motor shaft (12). The outer wall of the ball bearing (7) is fixedly connected to the plastic cover (8). A stator assembly is provided on the outer wall of the rotor core (9).

2. The brushless motor for power tools according to claim 1, characterized in that: The stator assembly includes a front wire frame (1) and a rear wire frame (4). Multiple iron chips (2) are fixedly connected between the front wire frame (1) and the rear wire frame (4). The rotor core (9) is located between the multiple iron chips (2). Enamelled wire (3) is wound around the outer wall of the iron chips (2).

3. A brushless motor for power tools according to claim 2, characterized in that: One end of the enameled wire (3) is fixedly connected to a terminal (5), and a Hall plate (6) is fixedly connected to the side wall of the rear wire frame (4) away from the front wire frame (1). One end of the terminal (5) is fixedly connected to the Hall plate (6).

4. A brushless motor for power tools according to claim 2, characterized in that: The rear cable tray (4) is connected to the side wall of the plastic cover (8), and the front cable tray (1) is connected to the side wall of the fan blade (11).

5. A brushless motor for power tools according to claim 4, characterized in that: The rotor core (9) is provided with a front cover (13) and a rear cover (15) at both ends. The front cover (13) is installed on one side of the stator assembly, and the rear cover (15) is installed on the other side of the stator assembly. A screw (16) is threaded between the front cover (13) and the rear cover (15). A wave-shaped gasket (14) is provided between the motor shaft (12) and the rear cover (15).

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