CN214255975U

CN214255975U - Hand-held electric tool

Info

Publication number: CN214255975U
Application number: CN202023333748.3U
Authority: CN
Inventors: 张席平
Original assignee: Jiangsu Dongcheng Tools Technology Co Ltd
Current assignee: Jiangsu Dongcheng Tools Technology Co Ltd
Priority date: 2020-12-30
Filing date: 2020-12-30
Publication date: 2021-09-21
Anticipated expiration: 2030-12-30

Abstract

A handheld electric tool comprises a shell, a motor arranged in the shell, a gear box driven by the motor and fan blades; the gearbox comprises a box body, a transmission gear set arranged in the box body, a gearbox cover arranged at the rear part of the box body and a gasket which is arranged between the gearbox cover and the transmission gear set and used for preventing grease from overflowing; the transmission gear set is provided with a planetary gear driven by the motor and an inner gear ring meshed with the planetary gear; a ventilation opening is formed in the side, corresponding to the inner gear ring of the transmission gear set, of the box body, a notch corresponding to the ventilation opening is formed in the gear box cover, and an air inlet communicated with the ventilation opening is formed in the shell; the inner side of the gear box cover is provided with a convex part for pushing the gasket, the ventilation opening and the gap form an air duct, and the handheld electric tool reduces the possibility that dust enters the inside of the gear box and lubricating grease overflows the outside of the gear box while air cooling is carried out.

Description

Hand-held electric tool

[ technical field ] A method for producing a semiconductor device

The utility model relates to an electric tool technical field, in particular to electric tool of hand-held type.

[ background of the invention ]

The existing hand-held electric tool is usually provided with a cooling structure for cooling the motor, but a primary drive gear in the gear box is fast in rotating speed due to direct meshing with an output shaft of the motor, the heat productivity is extremely high, the drive gear is worn due to high-speed operation, so that the normal service life of the gear box is influenced, meanwhile, the integral temperature rise of the gear box can also cause grease used for lubricating the gears in the gear box to be gasified or carbonized too early, the dry grinding condition of the gears occurs, and the integral service life of the gear box can be greatly influenced if the heat in the gear box is not dissipated out in time.

Accordingly, there is a need for an improved hand-held power tool that overcomes the deficiencies of the prior art.

[ Utility model ] content

The utility model aims to provide a not enough to prior art, the utility model aims to provide a handheld electric tool, this handheld electric tool when carrying out the forced air cooling, has reduced the dust and has got into inside and the lubricating grease of gear box and spilled over the outside possibility of gear box.

The utility model provides a technical scheme that prior art problem adopted is: a handheld electric tool comprises a shell, a motor arranged in the shell, a gear box driven by the motor and fan blades driven by the motor; the gearbox comprises a box body, a transmission gear set arranged in the box body, a gearbox cover arranged at the rear part of the box body and a gasket which is arranged between the gearbox cover and the transmission gear set and used for preventing grease from overflowing; the transmission gear set is provided with a planetary gear driven by the motor and an inner gear ring meshed with the planetary gear; a ventilation opening is formed in the box body corresponding to the side of the inner gear ring of the transmission gear set, a notch corresponding to the ventilation opening and allowing cooling airflow to pass through is formed in the gear box cover, and an air inlet communicated with the ventilation opening is formed in the shell; and a convex part for pushing the gasket is arranged on the inner side of the gear box cover, the inner gear ring is pressed in the box body, and the ventilation opening and the notch form an air channel.

Preferably, the fan blades are centrifugal fan blades, are arranged behind the motor and rotate coaxially with a motor shaft of the motor to generate the cooling airflow, and the cooling airflow passes through the inner gear ring and the outer surface of the gasket, passes through the air channel and flows through the interior of the motor; and air outlets are formed in the shell corresponding to the peripheries of the fan blades.

Preferably, the edge of the gear box cover is provided with a buckling arm protruding forwards, and the buckling arm protrudes into the ventilation opening to limit the relative displacement between the gear box cover and the box body.

Preferably, the transmission gear set comprises a multi-stage transmission gear set, and the planet gear and the inner gear ring are first-stage transmission gear sets.

Preferably, the box body comprises a front box body and a rear box body which are connected with each other, and the first-stage transmission gear set is arranged in the rear box body.

Preferably, the transmission gear set further comprises a second-stage transmission gear set meshed with the first-stage transmission gear set, and a third-stage transmission gear set meshed with the second-stage transmission gear set, and the output end of the third-stage transmission gear set is connected with the working shaft of the handheld electric tool.

Preferably, the number of the notches is more than two, and the notches are circumferentially and uniformly distributed on the gear box cover by taking the axis of the gear box cover as a center.

Preferably, the number of the convex parts is more than two, one end of each convex part is fixedly connected in the notch, and the other end of each convex part is a free end which is pressed against the surface of the gasket and provides axial supporting force for the gasket.

Preferably, the motor is a brushless motor, and the motor includes a rotor and a stator assembly surrounding the rotor, and a ventilation gap is formed between the stator assembly and the rotor.

Preferably, the housing comprises a left half shell and a right half shell which are symmetrical to each other and assembled, and the left half shell and the right half shell respectively extend downwards to form a holding part.

Compared with the prior art, the utility model discloses following beneficial effect has: the side of the gear box body of the hand-held electric tool, which corresponds to the inner gear ring of the transmission gear set, is provided with a vent, the gear box cover is provided with a notch which corresponds to the vent and is used for cooling air to pass through, the cooling air can directly flow through the outer surfaces of the inner gear ring and the gasket to drive heat generated by the transmission gear set and flow out of the gear box from the notch, the cooling air can only flow through the outer surfaces of the inner gear ring and the gasket and can not drive dust into the transmission gear set, meanwhile, the gasket is pressed on the side surface of the inner gear ring by a convex part arranged on the gear box cover to press the inner gear ring in the box body, and lubricating grease in the gear box is relatively sealed in the gear box to avoid overflowing.

[ description of the drawings ]

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings:

fig. 1 is a perspective view of a hand-held power tool according to an embodiment of the present invention;

FIG. 2 is a schematic view of the cooling air flow of the hand held power tool of FIG. 1;

FIG. 3 is a schematic view of a wind tunnel of the hand-held power tool shown in FIG. 1;

FIG. 4 is a cross-sectional schematic view of the air chute of the hand-held power tool shown in FIG. 1;

FIG. 5 is a partial cross-sectional view of the hand held power tool shown in FIG. 1;

FIG. 6 is an exploded schematic view of a gearbox of the hand held power tool shown in FIG. 1;

fig. 7 is a schematic view of the structure of the gasket.

The meaning of the reference symbols in the figures:

100. the electric hand drill comprises an electric hand drill 10, a shell 101, a left half shell 102, a right half shell 103, a holding part 11, an air inlet 12, an air outlet 20, a front box body 21, a rear box body 211, a ventilation opening 212, a clamping groove 213, a step 22, a gear box cover 221, a notch 222, a convex part 223, a buckling arm 23, a first-stage transmission gear set 231, an inner gear ring 232, a planetary gear 233, a sun gear 24, a second-stage transmission gear set 25, a third-stage transmission gear set 3, a working shaft 4, a motor 41, a stator assembly 42, a rotor 43, a gap 44, a motor shaft 45, a motor gear 5, a fan blade 51, cooling air flow 52, an air duct 6, a gasket 7, a torque sleeve 8, a drill chuck 200 and a battery pack

[ detailed description ] embodiments

The present invention will be described in further detail with reference to the accompanying drawings and embodiments.

Referring to fig. 1 to 7, an embodiment of the handheld power tool of the present invention is specifically described by taking a handheld power drill 100 as an example, where the handheld power drill 100 includes a housing 10, a motor 4 disposed inside the housing 10, a gear box connected to a motor shaft 44 of the motor 4, and a fan blade 5 driven by the motor 4, in this embodiment, the housing 10 includes a left half shell 101 and a right half shell 102 that are symmetrical to each other and assembled, the left half shell 101 and the right half shell 102 respectively extend downward to form a grip portion 103, a battery pack 200 for providing power to the handheld power drill 100 is connected to a lower end of the grip portion 103, the motor 4 is a brushless motor, and includes a rotor 42 and a stator assembly 41 surrounding the outer ring of the rotor 42, a ventilation gap 43 is formed between the stator assembly 41 and the rotor 42, the motor shaft 44 is driven by the rotor 42 to rotate, the fan blade 5 is a centrifugal fan blade, and is arranged behind the motor 4 and rotates coaxially with the motor shaft 44 to generate cooling airflow 51.

Referring to fig. 5 and 6, the gearbox includes a casing, a transmission gear set disposed inside the casing for reducing the output rotation speed of the motor 4, and a gearbox cover 22 disposed at the rear of the casing for sealing the gearbox, the casing includes a front casing 20 and a rear casing 21 connected to each other, the casing may be made of a lower-cost plastic material or a more durable aluminum alloy material; drive gear group includes tertiary drive gear, be first order drive gear group 23 respectively, with the second level drive gear group 24 of first order drive gear group 23 meshing, and with the third level drive gear group 25 of second level drive gear group 24 meshing, the drive ratio between the tertiary drive gear reduces in proper order, first order drive gear group 23 set up in inside back box 21, gear case lid 22 center is provided with the confession the round hole that motor shaft 44 stretched into, gear case lid 22 border department is provided with the protruding knot of stretching forward and holds arm 223, detain hold arm 223 with the draw-in groove 212 cooperation that sets up on the back box 21, the restriction gear case lid 22 with back box 21 produces relative displacement.

The motor shaft 44 is in transmission connection with a first-stage transmission gear set 23 of the transmission gear set, the first-stage transmission gear set 23 comprises an inner gear ring 231, a planetary gear 232 meshed with the inner gear ring 231 and a sun gear 233 meshed with the output end of the planetary gear 232, the front part of the motor shaft 44 is connected with a motor gear 45, the motor gear 45 is arranged inside the gear box and meshed with the input end of the planetary gear 232, and the output end of the transmission gear set, namely the output end of the third-stage transmission gear set 25, is connected with a working shaft 3 driven by the motor 4.

A gasket 6 for preventing the grease in the box body from overflowing is arranged between the first-stage transmission gear set 23 and the gear box cover 22, in the embodiment, the gasket 6 is made of a metal material with better heat conduction performance, the gasket 6 is an annular metal gasket sleeved on the periphery of the motor shaft 44, the annular metal gasket covers the side surface of the inner gear ring 231, and the grease used for lubricating in the gear box is prevented from leaking out of the gear box.

Referring to fig. 2, a vent 211 is disposed on the case body corresponding to the side of the inner gear ring 231 of the transmission gear set, the vent 211 is disposed on the rear case body 21 and located above the inner gear ring 231, a notch 221 corresponding to the vent 211 and allowing the cooling airflow 51 to pass through is disposed on the gear case cover 22, the vent 211 is disposed near the notch 221, referring to fig. 3 and 4, the vent 211 and the notch 221 form an air duct 52 allowing the cooling airflow to pass through, in this embodiment, the vent 211 and the slot 212 are integrally disposed, the housing 10 is provided with an air inlet 11 corresponding to the vent 211, the air inlet 11 is located near the vent 211, an air outlet 12 is disposed on the housing 10 corresponding to the periphery of the fan blade 5, and after the cooling airflow 51 enters the handheld electric drill 100 from the air inlet 11, the cooling air flow 51 is blown to the outer surfaces of the inner gear ring 231 and the gasket 6 through the ventilation opening 211 arranged on the rear box body 21, passes through the gap 221, flows through the inside of the motor 4, passes through the gap 43, and is discharged from the air outlet 12, so that a large amount of heat is taken away, meanwhile, because the cooling air flow 51 is only blown to the outer surfaces of the inner gear ring 231 and the gasket 6, dust is not brought into the transmission gear set, and the requirements of heat dissipation and dust prevention are met; set up further the breach 221 is more than two, and with the axle center of gearbox lid 22 be central circumference equipartition in on the gearbox lid 22, in this embodiment the breach 221 is provided with two, and is corresponding the vent 211 sets up to two equally, the air intake 11 sets up to four, locates respectively half shell 101 in a left side with on half shell 102 in the right side, and for half shell 101 in a left side with the linking department symmetry of half shell 102 in the right side.

Referring to fig. 7, the inner side of the gear box cover 22 is provided with a convex portion 222 for pushing the gasket 6, the convex portion 222 presses the gasket 6 against the side surface of the ring gear 231 and presses the ring gear 231 against the inside of the box body, the convex portion 222 is provided with more than two parts corresponding to the notch 221, similarly in this embodiment, the convex portion 222 is provided with two parts, one end of the convex portion 222 is fixedly connected in the notch 221, the other end is a free end for pressing against the surface of the gasket 6, the convex portion 222 is deformed by the extrusion of the gasket 6 to provide an axial supporting force for the gasket 6 to press the gasket 6 against the side surface of the ring gear 231, an annular step 213 is formed in the inner circumferential direction of the rear box body 21, the other side surface of the ring gear 231 abuts against the step 213, and the gasket 6 relatively seals lubricating grease in the gear box, avoiding its overflow.

The front end of the front box body 20 is further provided with a torque sleeve 7 for adjusting the output torque of the handheld electric drill 100, the front end of the torque sleeve 7 is further provided with a drill chuck 8, and the drill chuck 8 is in transmission connection with the front end of the working shaft 3 and used for clamping tool accessories.

The present invention is not limited to the above-described embodiments. It will be readily appreciated by those skilled in the art that many alternatives to the disclosed hand-held power tool may be made without departing from the spirit and scope of the invention. The protection scope of the present invention is subject to the content of the claims.

Claims

1. A handheld electric tool comprises a shell, a motor arranged in the shell, a gear box driven by the motor and fan blades driven by the motor; the gearbox comprises a box body, a transmission gear set arranged in the box body, a gearbox cover arranged at the rear part of the box body and a gasket which is arranged between the gearbox cover and the transmission gear set and used for preventing grease from overflowing; the transmission gear set is provided with a planetary gear driven by the motor and an inner gear ring meshed with the planetary gear; the method is characterized in that: a ventilation opening is formed in the box body corresponding to the side of the inner gear ring of the transmission gear set, a notch corresponding to the ventilation opening and allowing cooling airflow to pass through is formed in the gear box cover, and an air inlet communicated with the ventilation opening is formed in the shell; and a convex part for pushing the gasket is arranged on the inner side of the gear box cover, the inner gear ring is pressed in the box body, and the ventilation opening and the notch form an air channel.

2. The hand-held power tool of claim 1, wherein: the fan blades are centrifugal fan blades, are arranged behind the motor and rotate coaxially with a motor shaft of the motor to generate the cooling air flow, and the cooling air flow passes through the inner gear ring and the outer surface of the gasket, passes through the air channel and flows through the interior of the motor; and air outlets are formed in the shell corresponding to the peripheries of the fan blades.

3. The hand-held power tool of claim 1, wherein: and the edge of the gear box cover is provided with a buckling arm which protrudes forwards, and the buckling arm protrudes into the ventilation opening to limit the relative displacement of the gear box cover and the box body.

4. The hand-held power tool of claim 1, wherein: the transmission gear set comprises a multi-stage transmission gear set, and the planet gear and the inner gear ring are first-stage transmission gear sets.

5. The hand-held power tool of claim 4, wherein: the box body comprises a front box body and a rear box body which are connected with each other, and the first-stage transmission gear set is arranged in the rear box body.

6. The hand-held power tool of claim 4, wherein: the transmission gear set further comprises a second-stage transmission gear set meshed with the first-stage transmission gear set and a third-stage transmission gear set meshed with the second-stage transmission gear set, and the output end of the third-stage transmission gear set is connected with the working shaft of the handheld electric tool.

7. The hand-held power tool of claim 1, wherein: the breach is provided with more than two, and with the axle center of gear box lid is central circumference equipartition in on the gear box lid.

8. The hand-held power tool of claim 7, wherein: the convex part is provided with more than two, one end of the convex part is fixedly connected in the gap, and the other end of the convex part is a free end which is pressed on the surface of the gasket and provides axial supporting force for the gasket.

9. The hand-held power tool according to any one of claims 1 to 8, wherein: the motor is a brushless motor, the motor comprises a rotor and a stator assembly surrounding the outer ring of the rotor, and a ventilating gap is formed between the stator assembly and the rotor.

10. The hand-held power tool according to any one of claims 1 to 8, wherein: the shell includes left half shell and right half shell that mutual symmetry and equipment were assembled, left half shell with right half shell downwardly extending forms the portion of gripping respectively.