TW202348913A - Transmission device of electric tool comprising a housing unit, a spindle rotatably mounted on the housing unit, a transmission unit and a limit unit mounted on the housing unit to reduce wear and improve service life - Google Patents

Abstract

A transmission device for an electric tool, which comprises a housing unit, a spindle rotatably mounted on the housing unit, a transmission unit and a limit unit mounted on the housing unit. The transmission unit is driven by an electric power to drive the main shaft to rotate, and includes at least two gear sets. One of the gear sets has a movable gear that moves relative to the other gear set between a fixed position and a rotating position. The limit unit includes a first ring member that abuts against the other gear set, and a second ring member that is spaced apart from the first ring member, and the second ring member can block the movable gear from being fixed to the fixed position, and restrict the rotation of the movable gear. In this way, the first ring member and the second ring member are spaced apart to disperse the force and select proper materials, resulting in reduced wear and improved service life.

Description

Power tool transmission

The present invention relates to an electric tool, and in particular to a transmission device of the electric tool.

Referring to Figure 1, a conventional gear device 1 of a handheld machine tool disclosed in U.S. Patent No. 8485935B2 can be driven by electric power and transmit power to a main shaft (not shown), and mainly includes at least two A gear set 11, 12, a switching member 13, an internal gear ring 14, and a retaining ring 15. The switching member 13 is an internal gear ring, capable of moving along a moving direction X and meshing with one of the gear sets 11 . The internal ring gear 14 meshes with the other gear set 12 . The retaining ring 15 has a side surface 151 that abuts the internal toothed ring 14 , and an internal toothed portion 152 that can engage with the switching member 13 and limit the rotation of the switching member 13 . Thereby, when the switching member 13 is separated from the retaining ring 15, it can rotate together with one of the gear sets 11. When the switching member 13 meshes with the retaining ring 14, it can produce a deceleration effect to achieve the purpose of speed change.

However, since the retaining ring 15 must simultaneously bear the thrust from the internal gear ring 14 along the moving direction Shorter lifespan. In addition, the selection of materials has the disadvantage of higher cost due to the requirement of higher structural strength and wear resistance.

Therefore, an object of the present invention is to provide a transmission device for an electric tool that can disperse the force and increase the service life.

Therefore, the transmission device of the electric tool of the present invention includes a housing unit, a spindle, a transmission unit, and a limiting unit.

The spindle is rotatably mounted on the housing unit.

The transmission unit is installed in the housing unit and can be driven by an electric power to drive the main shaft to rotate. The transmission unit includes at least two gear sets, wherein one of the gear sets has a gear that is operable relative to the other along an axis direction. The gear set has a movable gear that moves between a fixed position and a rotating position. When in the fixed position, the movable gear is fixed so that the transmission unit drives the main shaft to rotate at a first speed. When in the rotating position, the movable gear The movable gear can rotate, so that the transmission unit drives the main shaft to rotate at a second rotational speed greater than the first rotational speed.

The limiting unit is installed on the housing unit and includes a first ring member and a second ring member that is spaced apart from the first ring member along the axial direction and does not contact the first ring member. Close to the first ring body part of the other gear set, the second ring member has a second ring body part and a plurality of stop parts formed on an inner surface of the second ring body part. These stops The part is engaged with the movable gear at the fixed position to restrict the rotation of the movable gear.

The effect of the present invention is that the spaced first ring and the second ring respectively bear the thrust from one of the gear sets and the torsion from the movable gear, which can not only disperse the force, but also be able to target different effects. Make great efforts to select suitable materials to reduce wear and extend service life.

Referring to FIGS. 2 and 3 , an embodiment of the transmission device of the electric power tool of the present invention includes a housing unit 2 , a spindle 3 , a transmission unit 4 , and a limiting unit 5 .

The housing unit 2 includes two housings 21 and 22 that are aligned with each other along an axis X direction and define the power chamber 20 . The housing 21 has two first mounting surfaces 211 surrounding the axis The second mounting surface 212 (as shown in Figure 4).

The spindle 3 extends along the axis X direction and is rotatably mounted on the housing 21 , and has a penetration section 31 that penetrates the housing 21 .

Referring to Figures 3, 4 and 5, the transmission unit 4 is installed in the housing unit 2 and located in the power chamber 20, and can be driven by an electric power to drive the spindle 3 to rotate. The transmission unit 4 includes three gear sets 41, 42, and 43 arranged along the X direction of the axis.

The gear set 41 has a rotatable carriage 411 , three planetary gears 412 rotatably connected to the carriage 411 , a fixed gear 413 fixed on the housing 21 , and an elastic element group 414 . The carriage 411 has a sun gear portion 415 surrounding the axis X and engaged with the main shaft 3 . In this embodiment, the fixed gear 413 is a ring gear that surrounds and meshes with the planetary gears 412 . The elastic element group 414 is disposed between the housing 21 and the fixed gear 413 to constantly generate an elastic force to move the fixed gear 413 along the axis X direction in a direction opposite to the main shaft 3 .

The gear set 42 has a rotatable carriage 421, three planetary gears 422 rotatably connected to the carriage 421, and a planetary gear 422 fixed on the housing 22 and spaced apart from the fixed gear 413 along the axis X direction. Fixed gear 423. The carriage 421 has a sun gear portion 424 extending along the axis X direction. The planetary gears 422 are adapted to surround and mesh with a rotating shaft (not shown) of a motor (not shown). In this embodiment, the fixed gear 423 is a ring gear that surrounds and meshes with the planetary gears 422 .

The gear set 43 has a rotatable carriage 431 , three planetary gears 432 rotatably connected to the carriage 431 , and a movable gear 433 located between the fixed gears 413 and 423 . The carriage 431 has a sun gear portion 434 extending along the axis X direction and meshing with the planetary gears 412 . The planetary gears 432 surround and mesh with the sun gear portion 424 of the carriage 421 .

In this embodiment, the movable gear 433 is a ring gear that is operable to move along the axis X direction relative to the gear sets 41 between a fixed position (as shown in Figure 3) and a rotational position (as shown in Figure 6) . In the fixed position, the movable gear 433 is fixed, so that the transmission unit 4 drives the main shaft 3 to rotate at a first speed. In this rotational position, the movable gear 433 can rotate together with the gear sets 41 so that the transmission unit 4 drives the main shaft 3 to rotate at a second rotational speed greater than the first rotational speed.

The limiting unit 5 is installed between the housings 21 and 22 and includes a first ring 51 and a second ring 52 spaced apart from and not in contact with the first ring 51 along the axis X direction. .

The first ring member 51 has a first ring body portion 511 that abuts the fixed gear 413 , and two first mounting portions 512 extending from the first ring body portion 511 and connected to the first mounting surface 211 .

The second ring member 52 has a second ring body part 521, a plurality of second mounting parts 522 extending from the second ring body part 521 and connected to the second mounting surface 212, and a plurality of second mounting parts 522 formed on the second ring body part 521. The ring body part 521 has a stopper part 523 on the inner surface. The blocking portions 523 engage with the fixed position of the movable gear 433 to limit the rotation of the movable gear 433 .

Referring to Figures 3, 5 and 6, when the movable gear 433 is operated to move toward the fixed position along the axis The ring body part 521 blocks and is stabilized in a fixed position and meshes with the stopper parts 523 of the second ring member 52, so that the movable gear 433 is blocked by the stopper parts 523 and cannot rotate. And the planetary gears 422 driven by the rotating shaft (not shown) will simultaneously revolve around the axis X while following the rotation of the fixed gear 423, and drive the trailer 421 to rotate. At this time, the sun gear portion 424 of the trailer 421 will drive the planetary gears 432 during the rotation process, so that the planetary gears 432 will simultaneously revolve around the axis X while following the rotation of the movable gear 433, and The drag frame 431 is driven to rotate. Thereby, during the rotation of the sun gear portion 434 of the trailer 431, the planetary gears 412 are driven, so that the planetary gears 412 simultaneously revolve around the axis X while following the rotation of the fixed gear 413, and The main shaft 3 is driven to rotate at the first rotation speed by the sun gear portion 415 .

When the movable gear 433 is operated to be in the rotation position, since the movable gear 433 is separated from the stopper 523 of the second ring 52 , the planetary gears 422 driven by the rotating shaft (not shown) will While following the rotation of the fixed gear 423, it simultaneously revolves around the axis X and drives the trailer 421 to rotate. At this time, the sun gear portion 424 of the trailer 421 will drive the planetary gears 432 during the rotation process, and during the rotation and revolution of the planetary gears 432, the movable gear 433 will be synchronously driven to rotate around the axis X. And drive the trailer 431 to rotate, and can drive the planetary gears 412 during the rotation of the sun gear portion 434 of the trailer 431, so that the planetary gears 412 follow the rotation of the fixed gear 413, and at the same time It revolves around the axis X and drives the main shaft 3 to rotate at the second rotation speed through the sun gear portion 415 . Thereby, by operating the position of the movable gear 433, the purpose of speed change is achieved.

It is worth noting that the aforementioned structure and action for operating the movement of the movable gear 433 are not technical features of this case, and since those with ordinary knowledge in the art can infer the extended details based on the above description, no further description will be given.

It should be noted that the number of the gear sets 43 is not limited to 3 sets. In other variations of this embodiment, it can also be 2 sets, or 4 or more sets as shown in FIG. 7 . Thereby, as shown in Figure 7, the gear set 42 can be omitted, so that the planetary gears 432 are suitable for surrounding and meshing with the rotating shaft (not shown) of the motor (not shown), and can also be operated by operating the The position of the movable gear 433 achieves the purpose of speed change.

Through the above description, the advantages of the foregoing embodiments can be summarized as follows:

The present invention can use the first ring member 51 to block the fixed gear 413 from moving along the axis X direction and withstand the thrust of the fixed gear 413 along the axis X direction. And the second ring member 52 which is spaced apart and not in contact with the first ring member 51 bears the torsion force when the movable gear 433 rotates. Thereby, the first ring member 51 and the second ring member 52 are used to disperse the forces on different components, and materials with wear resistance and high hardness can be selected for different forces, thereby reducing wear and improving use. lifespan.

However, the above are only examples of the present invention, and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made based on the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. Within the scope covered by the patent of this invention.

2: Shell unit 20:Power room 21: Shell 211:First mounting surface 212: Second mounting surface 22: Shell 3: Spindle 31: wear out section 4: Transmission unit 41:Gear set 411:Trailer 412:Planetary gear 413:Fixed gear 414: Elastic component group 415:Sun gear part 42:Gear set 421:Trailer 422:Planetary gear 423:Fixed gear 424:Sun gear part 43:Gear set 431:Trailer 432:Planetary gear 433: Movable gear 434:Sun gear part 5:Limiting unit 51:First ring piece 511:First ring body part 512:First installation department 52:Second ring piece 521:Second Ring Body 522: Second installation department 523: Stopper X: axis

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a partial cross-sectional view illustrating a conventional gear device of a handheld machine tool disclosed in U.S. Patent No. 8485935B2; Figure 2 is a front view illustrating an embodiment of the transmission device of the electric tool of the present invention; Figure 3 is a cross-sectional view taken along line III-III in Figure 2; Figure 4 is an incomplete three-dimensional exploded view of this embodiment; Figure 5 is an incomplete three-dimensional assembly view of this embodiment; Figure 6 is a partial cross-sectional view of the embodiment; and Figure 7 is a cross-sectional view similar to Figure 3, but with a transmission unit containing two gear sets.

2: Shell unit

21: Shell

22: Shell

3: Spindle

31: wear out section

4: Transmission unit

41:Gear set

411:Trailer

412:Planetary gear

413:Fixed gear

414: Elastic component group

415:Sun gear part

42:Gear set

421:Trailer

422:Planetary gear

423:Fixed gear

424:Sun gear part

43:Gear set

431:Trailer

432:Planetary gear

433: Movable gear

434:Sun gear part

51:First ring piece

511:First ring body part

52:Second ring piece

521:Second Ring Body

523: Stopper

X: axis

Claims (7)

A transmission device for an electric tool, including: a shell unit; a spindle, rotatably mounted on the housing unit; A transmission unit is installed in the housing unit and can be driven by an electric power to drive the main shaft to rotate. The transmission unit includes at least two gear sets, one of which has a gear that can be operated relative to the other along an axis direction. A movable gear of the gear set that moves between a fixed position and a rotating position. At the fixed position, the movable gear is fixed so that the transmission unit drives the main shaft to rotate at a first speed. At the rotating position, The movable gear can rotate so that the transmission unit drives the main shaft to rotate at a second rotational speed greater than the first rotational speed; and A limiting unit is installed on the housing unit and includes a first ring member and a second ring member that is spaced apart from the first ring member along the axial direction and does not contact the first ring member. The first ring member has a Against the first ring body portion of the other gear set, the second ring member has a second ring body portion and a plurality of stop portions formed on an inner surface of the second ring body portion. The stop portion is engaged with the movable gear at the fixed position to limit the rotation of the movable gear. The transmission device of the electric tool according to claim 1, wherein the housing unit includes two housings that are aligned with each other along the axial direction and define a power chamber, the spindle extends along the axial direction, and the limiting unit located between the shells. The transmission device of the electric tool according to claim 2, wherein one of the housings of the housing unit has a plurality of first mounting surfaces surrounding the axis, and a plurality of first mounting surfaces surrounding the axis and in contact with the axis along the direction. A second mounting surface is spaced apart from the first mounting surface. The first ring member also has a plurality of first mounting parts extending from the first ring body part and connected to the first mounting surface. The second ring member also has a plurality of first mounting parts. A second mounting part extends from the second ring body part and is connected to the second mounting surface. The transmission device of the electric tool according to claim 1, wherein the other gear set has a fixed gear, the movable gear and the fixed gear are respectively a ring gear, and each gear set also has a rotatable drag gear. carrier, and a plurality of planetary gears rotatably connected to the carriage, the carriage has a sun gear portion surrounding the axis, the fixed gear surrounds and meshes with the planetary gears of the other gear set, the movable The gears surround and mesh with the planetary gears of one of the gear sets, and the sun gear of the other gear set meshes with the main shaft. The planetary gears of the one of the gear sets are suitable for meshing with a rotating shaft of a motor. . The transmission device of the electric tool according to claim 1, wherein the transmission unit includes three gear sets, the other gear set has a fixed gear, and the remaining gear set has a fixed gear, and the fixed gears are arranged along the The axes are spaced apart, and the movable gear of one of the gear sets is located between the fixed gears, and is a ring gear respectively with the fixed gears. Each gear set also has a rotatable carriage and several rotatable carriages. The planetary gears are groundly connected to the carriage, the carriage has a sun gear portion surrounding the axis, the movable gear surrounds and meshes with the planetary gears of one of the gear sets, and the fixed gears respectively surround the other The planetary gears of the gear set, and the planetary gears of the remaining gear set, each fixed gear also meshes with the planetary gears of the corresponding gear set, and the sun gear of one of the gear sets meshes with The planetary gears of the other gear set, the planetary gears of one of the gear sets are meshed with the sun teeth of the remaining gear set. The transmission device of the electric tool according to claim 4 or 5, wherein the other gear set also has an elastic element group, the elastic element group is arranged between the housing and the fixed gear, and the fixed gear is constantly generated The elastic force that moves along this axis in the direction opposite to the main axis. The transmission device of the electric tool according to claim 1, wherein the second ring body portion of the second ring member is used to block the movable gear to stabilize the movable gear in the fixed position.