Motor unit

Abstract

A motor assembly comprises a motor unit housed within a housing. The motor unit includes a stator housing fixed within the housing. The stator and rotor of the motor are mounted within the stator housing. An output shaft connected to the rotor passes through the center of the stator housing. A cover plate and a rear cover abut against the front and rear end faces of the stator housing and the motor stator, respectively. Multiple bolts pass through the rear cover and the motor stator and are screwed onto the cover plate, axially limiting and fixing the stator within the stator housing. A motor mounting base is attached to the front end of the housing, with a bearing at its center for the output shaft to pass forward. The motor mounting base is spaced apart from the motor assembly. When the output shaft of this invention is connected to the impact device of a power tool, the vibration of the output shaft is transmitted to the housing and does not directly act on the bolts of the motor assembly, preventing bolt damage from vibration and facilitating the installation of the motor assembly.

Description

Technical Field

[0001] This invention relates to the construction of a motor; more particularly to a motor device with an assembly structure that is vibration-resistant and easy to install. Background Technology

[0002] The existing motor structure combines the stator housing inside the outer casing, and then the motor stator is bolted to the stator housing by bolts passing through the front cover, motor stator and rear cover. The magnetic field generated by the motor stator drives the internal motor rotor to output axial power outward.

[0003] The aforementioned motor structure requires screwing together the front cover, motor stator, and rear cover to secure the motor stator, making assembly inconvenient and time-consuming. Furthermore, when the motor structure is installed on a power tool, the vibration generated by the reaction force of the impact device on the output shaft is transmitted to the front cover, subjecting the bolted area between the front cover and the motor stator to radial shear force. This easily damages the bolts, shortening the structure's lifespan. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a motor device that utilizes a structure in which the motor assembly and the motor mounting base are respectively connected to the housing, thereby avoiding damage to fasteners such as bolts due to vibration, and simplifying the assembly components of the motor assembly, thus having the advantages of easy assembly, disassembly and maintenance.

[0005] To achieve the above objectives, the present invention provides a motor device, including a housing, a motor assembly, and a motor mounting base. The motor assembly includes a stator housing, a motor stator, an output shaft, a motor rotor, a pressure plate, and a rear cover. The stator housing is fixed within the housing with a rotational direction limited about the output shaft. The motor stator is embedded inside the stator housing, and multiple through holes are provided around the motor stator. The output shaft passes through the center of the stator housing. The motor rotor is coupled to the portion of the output shaft located within the circumferential range of the motor stator. The pressure plate abuts against the front end face of the stator housing and the motor stator and has multiple screw holes. The rear cover abuts against the rear end face of the stator housing and the motor stator and has multiple through holes. A bolt passes through each of the through holes, and each bolt passes through the through hole and is screwed into the screw hole of the pressure plate. The rear cover has a rear bearing, and the output shaft passes through the rear bearing. The motor mounting base is attached to the front end face of the housing and is provided with a front bearing. The output shaft passes through the front bearing, and the motor mounting base and the motor assembly are spaced apart.

[0006] The advantage of this invention is that there is a gap between the motor mounting base and the motor assembly, meaning they do not contact each other. Therefore, when the output shaft is connected to the vibration device, even if it vibrates due to a reaction force, the vibration will not directly affect the motor assembly but will first be transmitted to the housing for absorption. This prevents the bolts of the motor assembly from bearing shear force, ensuring that the motor assembly is not easily damaged under long-term vibration. Furthermore, since the motor assembly is assembled by first placing the pressure plate against the front end face of the motor stator, the motor stator can be bolted to the rear cover. This facilitates easy installation, assembly, disassembly, and maintenance. Attached Figure Description

[0007] Figure 1 This is a perspective view of a preferred embodiment of the present invention.

[0008] Figure 2 This is an exploded view of the preferred embodiment of the present invention described above.

[0009] Figure 3 This is an exploded view of another preferred embodiment of the present invention.

[0010] Figure 4 This is an exploded view of the motor mounting bracket of the preferred embodiment of the present invention.

[0011] Figure 5 This is a front view of the preferred embodiment of the present invention described above.

[0012] Figure 6 for Figure 5 6-6 direction cross section view.

[0013] Figure 7 for Figure 6 Enlarged view of the circled area.

[0014] Figure 8 for Figure 5 8-8 direction cross section view.

[0015] Figure 9 This is a top view of the preferred embodiment of the present invention described above.

[0016] Figure 10 for Figure 9 10-10 direction cross section view. Detailed Implementation

[0017] To more clearly illustrate the present invention, preferred embodiments are described in detail below with reference to the accompanying drawings. Please refer to... Figures 1 to 8 As shown, a preferred embodiment of the present invention is a motor device 100, which includes a housing 10, a motor assembly 20 and a motor mounting base 30.

[0018] The outer shell 10 is a housing with an internal mounting space 12. The front end of the outer shell 10 has a front face 14. In this preferred embodiment, the outer shell 10 is a plastic housing and includes a top shell 16 and a bottom shell 18 that fit together vertically. In other preferred embodiments, the outer shell 10 may be a housing made of other materials, such as composite materials, and the structure of the outer shell 10 may include left and right half-shells or a one-piece molded housing.

[0019] The motor assembly 20 is installed within the mounting space 12 of the housing 10. The motor assembly 20 includes a stator housing 21, a motor stator 22, an output shaft 23, a motor rotor 24, a pressure plate 25, and a rear cover 26. The stator housing 21 is an annular body, and the stator housing 21 is fixed within the housing 10 with its rotation direction limited about the output shaft 23. The inner circumferential surface of the stator housing 21 has a plurality of spaced recesses 211.

[0020] The motor stator 22 is embedded inside the stator housing 21. The outer circumferential surface of the motor stator 22 has a plurality of spaced protrusions 221. When the motor stator 22 is assembled inside the stator housing 21, it moves into the stator housing 21 concentrically along the same axial direction as the stator housing 21. The plurality of protrusions 221 around the motor stator 22 are respectively embedded in the plurality of recesses 211 of the stator housing 21, so that the motor stator 22 cannot rotate relative to the stator housing 21 after it is installed in the stator housing 21. The plurality of protrusions 221 around the motor stator 22 are each provided with a through hole 222, and the extending direction of each through hole 222 is parallel to the axial direction of the output shaft 23.

[0021] The output shaft 23 passes through the center of the area surrounding the stator housing 21. The stator housing 21, the motor stator 22, and the output shaft 23 are concentrically arranged. The motor rotor 24 is coupled to the portion of the output shaft 23 located within the area surrounding the motor stator 22, and the motor rotor 24 is spaced apart from the motor stator 22. The pressure plate 25 is an annular plate that abuts against the front end face of the stator housing 21 and the motor stator 22 and is provided with multiple screw holes 251. The rear cover 26 abuts against the stator housing 21 and the rear end face of the motor stator 22 and is provided with a plurality of through holes 261. A bolt 27 is inserted through each of the through holes 261. Each bolt 27 passes through the through hole 222 and is screwed into the screw hole 251 of the rear cover 26, so that the pressure plate 25 cooperates with the rear cover 26 to clamp and fix the motor stator 22 in the stator housing 21. The rear cover 26 cooperates with the output shaft 23 to embed a rear bearing 262 in the center, and the rear end of the output shaft 23 passes through the rear bearing 262.

[0022] The motor mounting bracket 30 is screwed onto the front end face 14 of the housing 10 and encloses the mounting space 12. A front bearing 32 is centrally embedded in the motor mounting bracket 30 in conjunction with the output shaft 23. The output shaft 23 passes through the front bearing 32, and its front end protrudes forward from the housing 10. The motor mounting bracket 30 and the motor assembly 20 are spaced apart. Specifically, the motor mounting bracket 30 and the motor assembly 20 have no structural contact.

[0023] When the motor assembly 100 of the present invention is installed on a power tool with an impact device, the output shaft 23 connected to the impact device will vibrate due to the reaction force of the impact device. Since the motor mounting base 30 and the motor assembly 20 are not in contact in construction, the vibration generated by the force on the output shaft 23 is mainly transmitted to the housing 10 for absorption through the front bearing 32 and the motor mounting base 30. There will be no shear force sufficient to damage each of the bolts 27 transmitted to each bolt 27, thus ensuring that the motor assembly 20 is not easily damaged under long-term vibration.

[0024] Furthermore, when assembling the motor assembly 100, simply place the pressure plate 25 on the front side of the motor stator 22 and the stator housing 21, and then screw each bolt 27 through the rear cover 26 and the motor stator 22 onto the pressure plate 25 to fix the motor stator 22 to the inside of the stator housing 21. Next, place the motor assembly 20 into the housing 10 and attach the motor mounting base 30 to the front end face 14 of the housing 10 to complete the assembly, making the structure of the present invention easy to assemble and disassemble.

[0025] Further details of the preferred embodiments described above can be found in the attached document. Figures 2 to 3 and Figures 9 to 10 As shown, the inner surface of the outer casing 10 has multiple slots 11. In this preferred embodiment, there are two slots 11 located at the middle of the inner surface of the top casing 16 and the middle of the inner surface of the bottom casing 18, respectively. The outer surface of the stator casing 21 has inserts 212 corresponding to the position and number of slots 11. The multiple inserts 212 are respectively embedded in the multiple slots 11, thereby fixing the stator casing 21 in the rotational direction and axial direction within the outer casing 10. This structure also reduces the vibration transmission from the outer casing 10 to the motor assembly 20. To control the operation of the motor device 100, a Hall element circuit board 40 is fixed at the rear end of the motor stator 22. The Hall element circuit board 40 is located inside the rear cover 26 and electrically connected to the motor stator 22 to control the rotational speed of the motor rotor 24 and the output shaft 23.

[0026] Please refer to Figures 2 to 4As shown, an annular stepped portion 213 is recessed into the inner side of the front end face of the stator housing 21, and an annular flange portion 214 is formed on the outer side of the stepped portion 213. The thickness of the pressure plate 25 along the axial direction is shallower than the depth of the stepped portion 213, and the periphery of the pressure plate 25 abuts against the inner surface of the stepped portion 213 for positioning. The motor mounting base 30 includes a base plate 34 and a front cover 36. The base plate 34 is screwed and fixed to the front end face 14 of the housing 10. The base plate 34 has a plurality of locking holes 341 around its periphery. In this preferred embodiment, four locking holes 341 are arranged in a matrix at intervals around the periphery of the base plate 34. The base plate 34 has a front through hole 342 in the center, and the front end of the output shaft 23 passes forward through the front through hole 342.

[0027] The front cover 36 is annular and concentrically joined to the inner side of the seat plate 34. A front bearing seat 361 is formed in the middle of the front cover 36, and the front bearing 32 is embedded and fixed in the front bearing seat 361. A cover plate 362 is provided around the front cover 36. Please refer to [link / reference]. Figures 6 to 8 As shown, the cover plate 362 is a ring extending rearward. The rear edge of the cover plate 362 extends into the stepped portion 213 and is located directly in front of the pressure plate 25. The rear end of the cover plate 362 is spaced apart from the pressure plate 25, and the inner part of the cover plate 362 is radially located within the area surrounded by the flange portion 214, making it difficult for dust to enter the stator housing 21 from the gap between the cover plate 362 and the flange portion 214. Furthermore, a fan blade 231 is fitted onto the portion of the output shaft 23 within the area surrounded by the cover plate 362. By rotating together with the output shaft 23, the fan blade 231 can drive the air flow on the front side of the motor stator 22, improving the heat dissipation effect inside the motor assembly 20.

[0028] The above description is only a preferred embodiment of the present invention. Any equivalent changes made by applying the present invention specification and the claims should be included within the patent scope of the present invention.

[0029] Explanation of reference numerals in the attached figures

[0030] [This invention]

[0031] 100: Motor unit

[0032] 10: Outer shell

[0033] 11: Recessed groove

[0034] 12: Installation space

[0035] 14: Front end

[0036] 16: Top shell

[0037] 18: Bottom shell

[0038] 20: Motor assembly

[0039] 21: Stator housing

[0040] 211: concave part

[0041] 212: Block

[0042] 213: Stepped section

[0043] 214: Flange portion

[0044] 22: Motor stator

[0045] 221: convex part

[0046] 222: Through hole

[0047] 23: Output shaft

[0048] 231: Fan blade

[0049] 24: Motor rotor

[0050] 25: Pressure plate

[0051] 251: Screw hole

[0052] 26: Back cover

[0053] 261: Perforation

[0054] 262: Rear bearing

[0055] 27: Bolt

[0056] 30: Motor mounting bracket

[0057] 32: Front bearing

[0058] 34: Seat board

[0059] 341: Locking hole

[0060] 342: Front piercing

[0061] 36: Front Cover

[0062] 361: Front bearing housing

[0063] 362: Cover plate

[0064] 40: Hall element circuit board

Claims

1. A motor device, comprising: A shell; A motor assembly includes a stator housing, a motor stator, an output shaft, a motor rotor, a pressure plate, and a rear cover. The stator housing is fixed within the housing with a rotational direction limited about the output shaft. The motor stator is embedded inside the stator housing and has multiple through holes around it. The output shaft passes through the center of the stator housing. The motor rotor is coupled to the portion of the output shaft located within the area surrounding the motor stator. The pressure plate abuts against the front end faces of the stator housing and the motor stator and has multiple screw holes. The rear cover abuts against the rear end faces of the stator housing and the motor stator and has multiple through holes. A bolt passes through each through hole and is screwed into a screw hole in the pressure plate. The rear cover has a rear bearing, and the output shaft passes through the rear bearing. A motor mounting base is attached to the front end face of the housing and is provided with a front bearing. The output shaft passes through the front bearing. The motor mounting base and the motor assembly are spaced apart.

2. The motor device as claimed in claim 1, wherein, The stator housing is axially confined within the housing.

3. The motor device as claimed in claim 1 or 2, wherein, The motor mounting base includes a base plate and a front cover. The base plate is screwed to the front end face of the housing and has multiple locking holes around it. The base plate has a front through hole in the center, through which the front end of the output shaft protrudes forward. The front cover is an annular body and is concentrically attached to the inner side of the base plate. A front bearing seat is formed in the middle of the front cover, and the front bearing is embedded in the front bearing seat.

4. The motor device as claimed in claim 3, wherein, The inner side of the front end face of the stator housing is recessed to form an annular stepped portion, and the outer side of the stepped portion is formed with an annular flange portion. The pressure plate is an annular plate body and the periphery of the pressure plate abuts against the stepped portion for positioning.

5. The motor device as claimed in claim 4, wherein, The front cover has an annular cover plate around it. The rear end edge of the cover plate extends into the stepped portion and is located directly in front of the pressure plate. The rear end of the cover plate is spaced apart from the pressure plate, and the inner end portion of the cover plate is radially located within the area surrounded by the flange portion.

6. The motor device as claimed in claim 1 or 2, wherein, The inner surface of the housing has multiple grooves, and the outer surface of the stator housing has multiple inserts. The multiple inserts are respectively embedded in the multiple grooves, thereby limiting and fixing the stator housing within the housing.

7. The motor device as claimed in claim 6, wherein, The outer casing includes a top shell and a bottom shell that fit together. The inner surface of the outer casing is provided with two grooves, one groove being located on the inner surface of the top shell and the other groove being located on the inner surface of the bottom shell. Two inserts are provided on the outer surface of the stator outer casing, and the two inserts are respectively embedded in the two grooves for fixation.

8. The motor device as claimed in claim 3, wherein, The inner surface of the housing has multiple grooves, and the outer surface of the stator housing has multiple inserts. The multiple inserts are respectively embedded in the multiple grooves, thereby limiting and fixing the stator housing within the housing.

9. The motor device as claimed in claim 8, wherein, The outer casing includes a top shell and a bottom shell that fit together. The inner surface of the outer casing is provided with two grooves, one groove being located on the inner surface of the top shell and the other groove being located on the inner surface of the bottom shell. The outer surface of the stator outer casing is provided with two inserts, which are respectively embedded in the two grooves and fixed.

10. The motor device as claimed in claim 1 or 2, wherein, A Hall element circuit board is fixed at the rear end of the motor stator. The Hall element circuit board is located inside the rear cover and is electrically connected to the motor stator to control the rotational speed of the motor rotor and the output shaft.

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