Brushless non-inductive motor for shock-resistant lithium electric nail gun

Abstract

The utility model provides an anti-vibration brushless non-inductive motor for a lithium electric nail gun. The anti-vibration brushless non-inductive motor comprises a motor shaft, a rotor assembly, a stator assembly, a motor upper cover, a motor lower cover, motor fan blades and a motor gear, the motor upper cover and the motor lower cover are both of an integrally-formed structure, the motor upper cover and the motor lower cover are combined and connected to form a complete motor shell of a hollow structure, the stator assembly and the rotor assembly are installed in the motor shell, the motor fan blades are installed at the tail end of the motor lower cover, and the motor gear is installed at the head end of the motor upper cover. The split type structure of a traditional brushless motor is changed into an integrated structure, so that the joint of the upper connecting end of the motor upper cover and the lower connecting end of the motor lower cover becomes a unique joint, and after the joint is locked, the problem that a front cover, a middle shell and a rear cover of a traditional motor are easy to loosen under violent shaking when a nail gun uses a shoot nail is directly avoided; the connection stability of the motor is greatly improved, the fault rate of the motor in the nail gun is reduced, and the service life of the nail gun is prolonged.

Description

Technical Field

[0001] The utility model relates to the manufacturing of parts for nail guns, in particular to a brushless and inductive motor for a shock-resistant lithium-electric nail gun. Background Art

[0002] An electric nail gun (or nail gun for short) is a common tool used to drive nails into wood or walls. The firing process is as follows: When current flows through the motor, it starts to rotate, which pulls the spring backward, simultaneously moving the nail and the firing pin backward. When the firing pin reaches the preset position, the spring rebounds, driving the firing pin at high speed. The firing pin head strikes the end of the nail, and the impact force causes the nail to jump out of the nail magazine and become fixed to the work surface. Therefore, the motor is an essential driving component of the nail gun.

[0003] Traditionally, nail guns have mostly used pneumatic or AC control methods. While lithium-ion battery nail guns are also available, the vast majority rely on brushed motors. However, lithium-ion battery nail guns, utilizing a specially developed brushless, sensorless control method, require a brushless, sensorless motor. Compared to brushless systems, brushless systems offer advantages such as spark-free operation, reduced interference, fast response, high torque, and minimal maintenance. Sensorless systems also eliminate the need for sensors to determine position, resulting in lower control costs and no potential for malfunctions due to Hall effect element damage. However, the significant impact of firing a nail gun can cause the entire gun to vibrate violently, potentially loosening or damaging the motor connections, leading to connection failure. Therefore, a vibration-resistant brushless, sensorless motor is needed for lithium-ion battery nail guns. Summary of the Invention

[0004] The utility model provides a shock-resistant brushless and sensorless motor for a lithium-ion nail gun in order to solve the problem that a motor housing may become loose and a connection may fail due to severe shaking during use of the lithium-ion nail gun.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A brushless and sensorless motor for a shock-resistant lithium-ion nail gun, comprising a motor shaft, a rotor assembly, a stator assembly, a motor upper cover, a motor lower cover, a motor fan blade, and a motor gear;

[0007] The integrally formed upper motor cover includes an upper end surface and an upper connecting end, an upper shaft hole is provided on the upper end surface, the upper connecting end is an open structure and an upper connecting portion is provided on the periphery; the integrally formed lower motor cover includes a lower end surface and a lower connecting end, a lower shaft hole is provided on the lower end surface, the lower connecting end is an open structure and a lower connecting portion is provided on the periphery; the upper motor cover is sleeved on the motor shaft through the upper shaft hole, and the lower motor cover is sleeved on the motor shaft through the lower shaft hole, the upper connecting end is cooperatively connected with the lower connecting end and is fixed and locked by the upper connecting portion and the lower connecting portion to form a complete motor housing with a hollow structure;

[0008] The stator assembly is fixedly mounted in cooperation with the inside of the motor upper cover and the motor lower cover, and the rotor assembly is sleeved and fixed on the motor shaft and is located inside the stator assembly; the motor fan blade is mounted on one end of the motor shaft close to the lower end surface, and the motor gear is mounted on one end of the motor shaft close to the upper end surface.

[0009] Preferably, the inner side surface of the motor upper cover and the inner side surface of the motor lower cover respectively match the concave and convex shapes of the corresponding parts of the outer side surface of the stator assembly, that is, the outer side surface of the stator assembly is wedged and fixed to the inner side surface of the motor upper cover and the motor lower cover.

[0010] Preferably, the upper connecting part includes an upper locking hole and an upper matching column, and the lower connecting part includes a lower locking hole and a lower matching column; the upper locking hole and the upper matching column are cross-distributed on the periphery of the upper connecting end, and the upper matching column is convex along the axial direction of the motor shaft; the lower locking hole and the lower matching column are cross-distributed on the periphery of the lower connecting end, and the lower matching column is concave along the axial direction of the motor shaft; the number, position and shape of the upper locking holes correspond to those of the lower locking holes, and the number, position and shape of the upper matching columns correspond to those of the lower matching columns. When the motor upper cover and the motor lower cover are combined and connected, the upper matching columns and the lower matching columns are wedged and fixed one by one, and the upper locking holes and the lower locking holes correspond one by one and are locked and fixed by locking pieces.

[0011] Preferably, the upper mating column is correspondingly arranged at a radially inwardly convex position on the inner side of the upper cover of the motor, and the lower mating column is correspondingly arranged at a radially inwardly convex position on the inner side of the lower cover of the motor; that is, the radial thickness of the upper mating column is greater than the radial thickness of the upper connecting end, and the radial thickness of the lower mating column is greater than the radial thickness of the lower connecting end.

[0012] Preferably, the upper mating column protrudes radially outward from the motor upper cover, and the lower mating column protrudes radially outward from the motor lower cover.

[0013] Preferably, the upper locking hole and the upper matching column are integrally connected to the motor upper cover, and the lower locking hole and the lower matching column are integrally connected to the motor lower cover.

[0014] Preferably, when the motor upper cover and the motor lower cover are cooperatively installed, the upper connecting end and the lower connecting end are tightly connected.

[0015] Preferably, ventilation holes are provided on the upper end surface of the motor upper cover and the lower end surface of the motor lower cover.

[0016] Preferably, the blades of the motor fan blades extend radially with the motor shaft as the center, and the motor fan blades are used to send the flowing cold air into the interior of the motor along the ventilation holes after rotation.

[0017] Preferably, a gap is left between the motor fan blades and the lower end surface of the motor lower cover.

[0018] The outer shell of the brushless motor includes a front cover, a middle shell, and a rear cover, which are fixed separately to form the overall external frame of the brushless motor. When this split brushless motor is used in a nail gun, the nail gun will vibrate violently when firing, which can easily cause the front cover, middle shell, or rear cover to loosen, causing motor failure and affecting the use of the motor. Compared with the existing technology, the beneficial effects of the utility model are as follows:

[0019] The one-piece motor upper cover and one-piece motor lower cover are designed to be installed and connected from both ends of the motor shaft respectively, so that the junction of the motor upper cover and the motor lower cover becomes the only connection. After locking and fixing them, the overall motor frame formed is an integrated structure, which directly avoids the problem of traditional motor front cover, middle shell and rear cover being easy to loosen under severe shaking; even if the nail gun shakes violently inside when shooting nails, it will not affect the overall structural stability of the motor, thereby reducing the failure rate of the motor and extending the service life of the nail gun, while maintaining good heat dissipation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the overall structure of a brushless and inductive motor for a shock-resistant lithium-electric nail gun of the present invention;

[0022] Figure 2 This is an exploded view of a brushless and sensorless motor for a shock-resistant lithium-electric nail gun according to the present invention;

[0023] Figure 3 The figure is a schematic diagram of the internal structure of a brushless and inductorless motor for a shock-resistant lithium-electric nail gun according to the present invention.

[0024] Among them, the motor shaft 1, the patented component 2, the stator component 3, the motor upper cover 4, the motor lower cover 5, the motor fan blade 6, the motor gear 7, the ventilation hole 8; the upper end surface 41, the upper connecting end 42, the upper connecting part 43, the upper locking hole 431, the upper matching column 432, the upper shaft hole 411; the lower end surface 51, the lower connecting end 52, the lower connecting part 53, the lower locking hole 531, the lower matching column 532, and the lower shaft hole 511. DETAILED DESCRIPTION

[0025] In order to provide a further understanding of the purpose, structure, features, and functions of the present invention, the present invention is described in detail below with reference to the embodiments.

[0026] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0027] A brushless motor uses a permanent magnet rotor and windings as a stator. Compared to traditional brushed motors, it offers greater power, higher efficiency, lower noise, and a compact design, making it easier to install and use. However, brushless motors require components to conduct electrical energy between the rotor and stator. These components generate electromagnetic noise and heat during high power output. Therefore, brushless motors are often designed with a split structure to isolate this noise and heat at the rotor end, preventing heat accumulation throughout the motor and maintaining stable operation.

[0028] The outer shell of a common brushless motor includes a front cover, a middle cover, and a rear cover, which serve to construct the overall structure of the motor. The front cover, middle cover, and rear cover are installed and fixed separately, and the connection between them is weak. When this split brushless motor is used in a nail gun, the nail gun will vibrate violently when firing, which can easily cause the front cover, middle cover, or rear cover to loosen, causing motor failure and affecting the use of the motor. To address the above problems, this utility model has designed a shock-resistant brushless sensorless motor for lithium-ion nail guns. Its specific structure is as follows:

[0029] Please refer to Figure 1-Figure 3 A brushless and sensorless motor for a shock-resistant lithium-ion nail gun includes a motor shaft 1, a rotor assembly 2, a stator assembly 3, a motor upper cover 4, a motor lower cover 5, a motor fan blade 6, and a motor gear 7;

[0030] The integrally formed upper motor cover 4 includes an upper end surface 41 and an upper connecting end 42, the upper end surface 41 is provided with an upper shaft hole 411, the upper connecting end 42 is an open structure and is provided with an upper connecting portion 43 on the periphery; the integrally formed lower motor cover 5 includes a lower end surface 51 and a lower connecting end 52, the lower end surface 51 is provided with a lower shaft hole 511, the lower connecting end 52 is an open structure and is provided with a lower connecting portion 53 on the periphery; the upper motor cover 4 is sleeved on the motor shaft 1 through the upper shaft hole 411, and the lower motor cover 5 is sleeved on the motor shaft 1 through the lower shaft hole 511, the upper connecting end 42 is cooperatively connected with the lower connecting end 52 and is fixed and locked with the upper connecting portion 43 and the lower connecting portion 53 to form a complete motor housing with a hollow structure;

[0031] The stator assembly 3 is fixedly mounted inside the motor upper cover 4 and the motor lower cover 5, and the rotor assembly 2 is sleeved and fixed on the motor shaft 1 and located inside the stator assembly 3; the motor fan blade 6 is installed at one end of the motor shaft 1 close to the lower end surface 51, and the motor gear 7 is installed at one end of the motor shaft 1 close to the upper end surface 41.

[0032] The present invention redesigns the overall structure of a brushless motor. First, the split structure of the front cover, middle shell, and rear cover is replaced with a wrapped, integrated structure of the motor upper cover 4 and the motor lower cover 5. The motor upper cover 4 and the motor lower cover 5 are both integrally formed structures. After being relatively installed and the upper connecting portion 43 and the lower connecting portion 53 are connected and fixed, the complete motor housing formed can enclose the stator assembly 3 and the rotor assembly 2. The motor upper cover 4 of the present invention is equivalent to combining and integrating the front cover and a portion of the middle shell of a traditional motor. The motor lower cover 5 of the present invention is equivalent to combining and integrating the rear cover and a portion of the middle shell of a traditional motor. The split structure is replaced with an integrated structure, so that the junction of the upper connecting end 42 of the motor upper cover 4 and the lower connecting end 52 of the motor lower cover 5 becomes the only connection point. After being locked, the problem of the traditional motor front cover, middle shell, and rear cover being easily loosened under severe shaking is directly avoided, and the connection stability of the motor is greatly improved, thereby reducing the failure rate of the motor in the nail gun and extending the service life of the nail gun.

[0033] In some embodiments, the inner side surface of the motor upper cover 4 and the inner side surface of the motor lower cover 5 respectively match the concave and convex shapes of the corresponding parts of the outer side surface of the stator assembly 3, that is, the outer side surface of the stator assembly 3 is wedged and fixed to the inner side surface of the motor upper cover 4 and the motor lower cover 5; this structure can improve the connection strength between the stator assembly 3 and the motor upper cover 4 and the motor lower cover 5, thereby further improving the overall stability of the motor as a whole under shaking or vibration conditions.

[0034] Specifically, the outermost part of the stator assembly 3 of the motor is silicon steel sheets arranged evenly at intervals in the circumferential direction, with gaps left between the silicon steel sheets. During actual installation, only the upper half of the stator assembly 3 is located inside the motor cover 4. Therefore, a circumferential boss is provided inside the motor cover 4 at a corresponding position on the top of the stator assembly 3 to abut against the top of the stator assembly 3 to prevent it from moving axially. At the same time, an axially extending convex structure is provided inside the motor cover 4 at the position of the gap between the silicon steel sheets on the side of the stator assembly 3, which can better fix the stator assembly 3. Similarly, only the lower half of the stator assembly 3 is located inside the summer lower cover, and a corresponding concave-convex structure is provided inside the motor lower cover 5. Finally, after the motor upper cover 4 is connected and locked with the motor lower cover 5, the axial displacement and circumferential rotation of the stator assembly 3 inside it are restricted and fixed, thereby making the overall structural stability of the motor stronger.

[0035] In some preferred embodiments, the upper connecting portion 43 includes an upper locking hole 431 and an upper matching column 432, and the lower connecting portion 53 includes a lower locking hole 531 and a lower matching column 532; the upper locking hole 431 and the upper matching column 432 are cross-distributed on the periphery of the upper connecting end 42, and the upper matching column 432 is convex along the axial direction of the motor shaft 1; the lower locking hole 531 and the lower matching column 532 are cross-distributed on the periphery of the lower connecting end 52, and the lower matching column 532 is concave along the axial direction of the motor shaft 1; the number, position and shape of the upper locking hole 431 and the lower locking hole 531 correspond to each other, and the number, position and shape of the upper matching column 432 and the lower matching column 532 correspond to each other. When the motor upper cover 4 and the motor lower cover 5 are combined and connected, the upper matching column 432 and the lower matching column 532 are wedged and fixed one by one, and the upper locking hole 431 and the lower locking hole 531 correspond one by one and are locked and fixed by a locking piece. Each set of corresponding upper locking holes 431 and lower locking holes 531 can be locked and fixed by screws, pins, etc., and the upper matching columns 432 and lower matching columns 532 are locked with each other in a concave and convex manner, so that the connection between the motor upper cover 4 and the motor lower cover 5 is not only locked and fixed by the upper locking holes 431 and the lower locking holes 531, but also additionally wedged and locked. The double locking method further enhances the overall connectivity of the motor and prevents the motor from loosening due to the vibration of the nail gun.

[0036] In some preferred embodiments, the upper engaging post 432 is disposed at a radially inwardly protruding position on the inner side of the motor upper cover 4, and the lower engaging post 532 is disposed at a radially inwardly protruding position on the inner side of the motor lower cover 5; that is, the radial thickness of the upper engaging post 432 is greater than the radial thickness of the upper connecting end 42, and the radial thickness of the lower engaging post 532 is greater than the radial thickness of the lower connecting end 52. By utilizing the internal boss structure provided on the inner sides of the motor upper cover 4 and the motor lower cover 5 to better secure the stator assembly 3, the upper engaging post 432 and the lower engaging post 532 are disposed at corresponding positions, thereby increasing the thickness of the upper engaging post 432 and the lower engaging post 532, thereby acting as a reinforcing rib, enhancing the overall strength of the motor housing, and making the upper and lower engaging posts more secure when wedged.

[0037] In some preferred embodiments, the upper mating column 432 protrudes radially outward from the motor upper cover 4, and the lower mating column 532 protrudes radially outward from the motor lower cover 5. From the outside of the motor, both the upper mating column 432 and the lower mating column 532 protrude outward, which helps assemblers to quickly locate and complete assembly.

[0038] In some preferred embodiments, the upper locking hole 431 and the upper matching column 432 are integrally connected to the motor upper cover 4, and the lower locking hole 531 and the lower matching column 532 are integrally connected to the motor lower cover 5. The one-piece molded structure is conducive to enhancing the strength of the motor upper cover 4 and the motor lower cover 5.

[0039] In some embodiments, when the motor upper cover 4 and the motor lower cover 5 are cooperatively installed, the upper connecting end 42 and the lower connecting end 52 are tightly connected.

[0040] In some embodiments, ventilation holes 8 are provided on both the upper end surface 41 of the motor upper cover 4 and the lower end surface 51 of the motor lower cover 5. This facilitates effective heat dissipation of the integrated motor of the present invention, prevents heat accumulation, and thereby extends the service life of the motor. Furthermore, the blades of the motor fan blades 6 extend radially about the motor shaft 1. The motor fan blades 6 rotate to direct cool air into the interior of the motor along the ventilation holes 8. The air is blown in through the motor lower cover 5, passes through the interior of the motor from bottom to top, cools the entire interior of the motor, and is then blown out through the ventilation holes 8 of the motor upper cover 4.

[0041] In some embodiments, a gap is left between the motor fan blades 6 and the lower end surface 51 of the motor lower cover 5 to facilitate the flow of cold air into the interior of the motor through the through holes, thereby enhancing air flow and improving the air cooling effect.

[0042] The present invention has been described with reference to the above embodiments. However, these embodiments are merely exemplary embodiments of the present invention. It should be noted that the disclosed embodiments do not limit the scope of the present invention. On the contrary, modifications and improvements made without departing from the spirit and scope of the present invention are within the scope of patent protection of the present invention.

Claims

1. A brushless, sensorless motor for a shock-resistant lithium-ion nail gun, characterized by: Including motor shaft, rotor assembly, stator assembly, motor upper cover, motor lower cover, motor fan blades and motor gears; The integrally formed upper motor cover includes an upper end surface and an upper connecting end, an upper shaft hole is provided on the upper end surface, the upper connecting end is an open structure and an upper connecting portion is provided on the periphery; the integrally formed lower motor cover includes a lower end surface and a lower connecting end, a lower shaft hole is provided on the lower end surface, the lower connecting end is an open structure and a lower connecting portion is provided on the periphery; the upper motor cover is sleeved on the motor shaft through the upper shaft hole, and the lower motor cover is sleeved on the motor shaft through the lower shaft hole, the upper connecting end is cooperatively connected with the lower connecting end and is fixed and locked by the upper connecting portion and the lower connecting portion to form a complete motor housing with a hollow structure; The stator assembly is fixedly mounted in cooperation with the inside of the motor upper cover and the motor lower cover, and the rotor assembly is sleeved and fixed on the motor shaft and is located inside the stator assembly; the motor fan blade is mounted on one end of the motor shaft close to the lower end surface, and the motor gear is mounted on one end of the motor shaft close to the upper end surface.

2. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 1, characterized in that: The inner side surfaces of the motor upper cover and the motor lower cover respectively match the concave and convex shapes of the corresponding parts of the outer side surface of the stator assembly, that is, the outer side surface of the stator assembly is wedged and fixed to the inner side surfaces of the motor upper cover and the motor lower cover.

3. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 2, characterized in that: The upper connecting part includes an upper locking hole and an upper matching column, and the lower connecting part includes a lower locking hole and a lower matching column; the upper locking hole and the upper matching column are cross-distributed on the periphery of the upper connecting end, and the upper matching column is convex along the axial direction of the motor shaft; the lower locking hole and the lower matching column are cross-distributed on the periphery of the lower connecting end, and the lower matching column is concave along the axial direction of the motor shaft; the number, position and shape of the upper locking holes correspond to those of the lower locking holes, and the number, position and shape of the upper matching columns correspond to those of the lower matching columns. When the motor upper cover and the motor lower cover are combined and connected, the upper matching columns and the lower matching columns are wedged and fixed one by one, and the upper locking holes and the lower locking holes correspond one by one and are locked and fixed by locking pieces.

4. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 3, characterized in that: The upper mating column is correspondingly arranged at a radially inwardly convex position on the inner side of the upper cover of the motor, and the lower mating column is correspondingly arranged at a radially inwardly convex position on the inner side of the lower cover of the motor; that is, the radial thickness of the upper mating column is greater than the radial thickness of the upper connecting end, and the radial thickness of the lower mating column is greater than the radial thickness of the lower connecting end.

5. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 4, characterized in that: The upper matching column protrudes outwardly from the motor upper cover along the radial direction, and the lower matching column protrudes outwardly from the motor lower cover along the radial direction.

6. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 5, characterized in that: The upper locking hole and the upper matching column are integrally connected to the motor upper cover, and the lower locking hole and the lower matching column are integrally connected to the motor lower cover.

7. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 1, characterized in that: When the motor upper cover and the motor lower cover are matched and installed, the upper connecting end and the lower connecting end are tightly connected.

8. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 1, characterized in that: Ventilation holes are provided on the upper end surface of the motor upper cover and the lower end surface of the motor lower cover.

9. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 8, characterized in that: The blades of the motor fan blades extend radially with the motor shaft as the center, and the motor fan blades are used to send the flowing cold air into the interior of the motor along the ventilation holes after rotation.

10. The brushless and inductive motor for a shock-resistant lithium-ion nail gun according to claim 9, characterized in that: A gap is left between the motor fan blades and the lower end surface of the motor lower cover.

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