Differential mechanism and movable electric tool with same

Abstract

The invention provides a differential mechanism and a movable electric tool with the differential mechanism. The differential includes an input mechanism, an output gear, a first conductive member, and a second conductive member. The input mechanism comprises a main input end and an auxiliary input end. When meshing between the output gear and the main input mechanism fails, the first conduction component and the second conduction component are connected, the second conduction component drives the first conduction component to rotate in the preset direction in the connection state, and therefore motion input of the auxiliary input end to the output gear is achieved. According to the differential mechanism, the effectiveness and stability of motion transmission can be guaranteed, and the slippage phenomenon is reduced.

Description

Technical Field

[0001] The present invention relates to the field of power tools, and more particularly to a differential and a movable power tool having the differential. The movable power tool is particularly a garden tool, such as a lawn mower or a snow blower. Background Art

[0002] In traditional movable power tools, a differential is usually provided between the left and right wheels. The differential can act to cause the left and right wheels of the movable power tool to have inconsistent speeds when turning, or when passing through special road surfaces, such as when the frictional forces of the road surfaces where the left and right wheels are located are different, the left and right wheel speeds also need to be different. However, the existing differential has a single power input source for the wheel axle. Once the power input from this power input source to the movement of the left and right wheels fails, the wheel axle cannot be driven to rotate, resulting in wheel slip.

[0003] Therefore, it is necessary to provide a differential and a movable power tool having the differential to at least partially solve the above problems. Summary of the Invention

[0004] The present invention provides a differential and a movable power tool having the differential. The differential of the present invention enables the input component to provide power input to the output component at two positions. Once the movement input from the main input end to the output component fails (such as incorrect gear meshing, gear idling, etc.), the auxiliary input end will act on the output component to continue to provide movement input to the output component, and the output component can still rotate with the input component. Therefore, the differential provided by the present invention can ensure the effectiveness and stability of motion transmission and reduce the occurrence of slip phenomena. Further, in some aspects of the present invention, the disengagement between the main input end and the output component can promote the engagement between the auxiliary input end and the output component, thereby further enhancing the stability and effectiveness of motion transmission, and further reducing the probability of slip phenomena.

[0005] According to one aspect of the present invention, there is provided a differential, which is configured to be able to drive the wheel axles installed on its left and right sides to rotate around the axis of the wheel axle. The differential includes:

[0006] An input mechanism, the input mechanism including a main input end and an auxiliary input end that rotate integrally around the axis;

[0007] An output gear, the output gear being fixedly engaged in the rotation direction with the wheel axle, and the output gear being located between the main input end and the auxiliary input end, wherein the output gear can be meshed with the main input end;

[0008] A first transmission member, the first transmission member being fixedly connected to the output gear in the rotation direction;

[0009] A second conductive member, which is fixedly connected to the auxiliary input end in the rotational direction.

[0010] Wherein, the first conductive member and the second conductive member face each other, and when the engagement between the output gear and the main input mechanism fails, the first conductive member and the second conductive member engage, and in this engaged state, the second conductive member drives the first conductive member to rotate in a predetermined direction.

[0011] In one embodiment, there is an axial displacement gap between the first conductive member and the output gear, and an elastic member is provided at the axial displacement gap. When the engagement between the output gear and the input mechanism fails, the output gear presses the elastic member so that the first conductive member engages with the second conductive member under the elastic force of the elastic member.

[0012] Preferably, the elastic member is in a compressed state both when the first conductive member and the second conductive member are in the engaged state and the non-engaged state.

[0013] In one embodiment, the first conductive member and the second conductive member form an annular sheet-like structure that is substantially perpendicular to the axis and surrounds the axis. The second conductive member has a protrusion facing the first conductive member, and the first conductive member has a recess facing the second conductive member. In the engaged state, the protrusion can be located within the recess, and the circumferential dimension of the recess is larger than the circumferential dimension of the protrusion.

[0014] Preferably, the protrusion and the recess are engaged through an inclined surface to facilitate the protrusion to disengage from or enter the recess.

[0015] In one embodiment, the input mechanism includes:

[0016] A differential housing, wherein the differential housing constitutes the auxiliary input end;

[0017] A planetary gear system located at the axial center position of the differential housing, and the planetary gear system includes:

[0018] An outer gear ring for receiving an external motion input;

[0019] A plurality of planetary gears mounted radially inside the outer gear ring, and the plurality of planetary gears constitute the main input end.

[0020] In one embodiment, the differential housing includes a pair of housing halves docked axially, and the outer gear ring is at least partially fixed between the pair of housing halves.

[0021] In one embodiment, the plurality of planetary gears are bevel gears, the self-rotation axis of each planetary gear extends in the radial direction, and a bevel gear is correspondingly formed at the axial inner end of the input gear.

[0022] In one embodiment, the differential further includes a central fitting located at its center, wherein the radially outer end of each self-rotation axis is inserted into a corresponding receiving hole of the outer gear ring, and the radially inner end of each self-rotation axis is inserted into a self-rotation axis mounting hole of the central fitting.

[0023] Preferably, the axial inner end of the axle is inserted into a corresponding receiving hole of the central fitting.

[0024] In one embodiment, the output gear includes an axially outer segment and an axially inner segment formed integrally, the outer diameter of the axially outer segment is smaller than the outer diameter of the axially inner segment, and both the first transmission member and the second transmission member surround the axially outer segment.

[0025] Specifically, the axle penetrates through the entire input gear and engages with the internal teeth of the input gear.

[0026] In one embodiment, the differential housing of the differential has a stepped structure adapted to the shape of the output gear.

[0027] In one embodiment, the first transmission member is fixedly bonded to the output gear, and / or the second transmission member is fixedly bonded to the auxiliary input end.

[0028] According to another aspect of the present invention, there is provided a movable power tool, which includes the differential according to any one of the above solutions and axles mounted on the left and right sides of the differential.

[0029] In one embodiment, the movable power tool is a lawn mower or a snow blower. Description of the Drawings

[0030] In order to better understand the above and other objects, features, advantages and functions of the present invention, reference may be made to the preferred embodiments shown in the drawings. The same or similar reference numerals in the drawings refer to the same or similar components. Those skilled in the art should understand that the drawings are intended to schematically illustrate the preferred embodiments of the present invention and have no restrictive effect on the scope of the present invention. The components in the drawings are not drawn to scale.

[0031] Figure 1A It is an external contour diagram of a differential according to some preferred embodiments of the present invention, with an axle mounted on each of the left and right sides of the differential;

[0032] Figure 1B Schematic diagram after removing the differential housing in Figure 1A , where the axle shafts on both sides of the differential are not fully shown;

[0033] Figure 1C Schematic diagram after removing the external gear ring in Figure 1B , where not all the planet gears are shown, for example, the planet gear at the bottom in this figure is omitted;

[0034] Figure 1D For Figure 1A Schematic diagram taken along line A - A in Figure 1D , where the axle shafts on both sides of the differential are not fully shown,

[0035] Figure 1E For Figure 1B Exploded schematic diagram of , where the axle shafts on both sides of the differential are not fully shown;

[0036] Figure 2 For Figure 1A Stereoscopic view of the differential shown in ;

[0037] Figure 3 For Figure 2 Explosion diagram of the differential shown in , Figure 3 Having approximately the same viewing angle as Figure 2 ;

[0038] Figure 4 For Figure 3 Separate stereoscopic views of the first conducting component and the second conducting component in ;

[0039] Figure 5 Schematic diagram in the joined state of the second conducting component and the differential housing half;

[0040] Figure 6A Schematic diagram after removing the differential housing half and the second conducting component from the differential, which shows the joining structure between the first conducting component and the output gear;

[0041] Figure 6B For Figure 6A Separate assembly schematic diagrams of the output gear, the first conducting component, and the elastic member in ;

[0042] Figure 7 Schematic diagram of the cooperation between the first conducting component, the second conducting component, the elastic member, and the output gear from the front view perspective, in which the first conducting component and the second conducting component are in an unjoined state;

[0043] Figure 8 For Figure 7Another view of the structure shown in the figure, where the first conductive component and the second conductive component are in an engaged state;

[0044] Figure 9 An electric tool according to some preferred embodiments of the present invention, in which a differential is provided Figure 1A-8 as shown in the figure.

[0045] Explanation of reference numerals:

[0046] 100 Axle

[0047] 101 Keyway of the axle

[0048] 102 Axial inner end of the axle

[0049] 200 Differential

[0050] 210 Differential housing

[0051] 211 Half of the differential housing

[0052] 2111 Axle hole

[0053] 2112 Middle section

[0054] 2113 Mounting base

[0055] 2114 Housing bonding projection

[0056] 2115 Mounting base projection

[0057] 220 Input mechanism

[0058] 221 Planetary gear system

[0059] 230 Outer gear ring

[0060] 231 Outer circumferential teeth

[0061] 232 Outer gear ring groove

[0062] 233 Assembly center piece

[0063] 2331 Self-rotating shaft mounting hole

[0064] 240 Bolt

[0065] 250 Planetary gear

[0066] 251 Self-rotating shaft

[0067] 260 Output gear

[0068] 261 Axial inner end teeth

[0069] 262 Gear bonding projection

[0070] 263 Axial inner section

[0071] 264 Axial outer section

[0072] 265 Internal teeth

[0073] 270 Spacer

[0074] 280 Second conduction component

[0075] 281 Bonding groove of the second conduction component

[0076] 282 Protrusion

[0077] 290 First conduction component

[0078] 291 Bonding groove of the first conduction component

[0079] 292 Depression

[0080] 293 Substrate section

[0081] 2010 Elastic member

[0082] 2011 Axial clearance

[0083] 283, 294 Inclined surface

[0084] 320 Lawn mower

[0085] 321 Rear wheel

[0086] 322 Front wheel

[0087] 323 Armrest Detailed implementation mode

[0088] Next, a cleaning device according to the present invention will be described in detail with reference to the accompanying drawings. The following is only the preferred implementation mode according to the present invention, and those skilled in the art can think of other ways to implement the present invention on the basis of the preferred implementation mode, and other ways also fall within the scope of the present invention.

[0089] The present invention provides a differential and a movable electric tool having the differential, such as a lawn mower, a snow blower, etc. Figure 1A - Figure 8 A differential according to some preferred implementation modes of the present invention is shown. The differential is configured to be able to drive the axle shafts installed on its left and right sides to rotate around the axis of the axle shaft (see Figure 1). Figure 1A-8 The differential shown in is particularly suitable for gardening tools, Figure 9 An example of a gardening tool is shown.

[0090] Figure 9 The gardening tool shown in is a lawn mower 320. In other implementation modes, the movable electric tool can also be a snow blower. Figure 9The lawn mower 320 shown in FIG. 1 is a four-wheeled electric tool having a front wheel 322 and a rear wheel 321 , and in some embodiments, may also have a handrail 323 for an operator to hold to manipulate the electric tool. Figure 1A - Figure 8 The differential shown can be used to connect between a pair of rear wheels 321 to play a differential role between the pair of rear wheels when one of the rear wheels of the lawn mower 320 slips or spins. The wheel axles 100 (see FIG. 1 ) on both sides of the differential 200 can be input components of the pair of rear wheels 321 of the lawn mower 320, for example, they can be used as shafts of the pair of rear wheels 321 of the lawn mower 320, or can be connected to the shafts of the pair of rear wheels 321 of the lawn mower 320 through a transmission or the like.

[0091] It should be noted that the main operating purpose of garden tools is gardening rather than carrying passengers, and garden tools usually face a large number of relatively extreme usage conditions, such as mud, ice and snow, fluffy grass, etc. Considering the size, deadweight, endurance, cost, etc. of garden tools, garden tools and passenger buses are quite different. The differential of the present invention is particularly suitable for garden tools with the above characteristics.

[0092] First of all, it should be noted that the direction and position terms of the present invention should be understood as relative directions and positions, and these direction and position terms should be interpreted with reference to the normal orientation of the differential and the movable power tool in use. For example, "axial" and "axial direction" can be understood as the extension direction of the axis X of the wheel axle; "radial" and "circumferential" can be understood as the radial and circumferential directions about the axial direction; "inward" refers to the direction pointing to the center of the differential; "outward" refers to the direction away from the center of the differential; "rotational direction" can be understood as the rotational direction around the axis X. In the present invention, the left-right direction and the axial direction are collinear.

[0093] refer to Figure 2 and Figure 3 The differential 200 includes an outer ring gear 230, a differential housing 210, a plurality of planetary gears 250, and an output gear 260. The differential housing 210 further includes a pair of housing halves 211 butted together in the axial direction, and the outer ring gear 230 is at least partially fixed between the pair of housing halves 211. The pair of housing halves 211 and the outer ring gear 230 together define the inner cavity of the differential 200.

[0094] Transfer back Figure 1A - Figure 1E, a pair of housing halves 211 and the components accommodated therein have substantially the same or similar structures. An external gear ring 230 is disposed between the pair of housing halves 211 and serves as a common input component for a pair of axles 100. An output gear 260, a first transmission component 290, a second transmission component 280, and an elastic member 2010 are disposed within each housing half. The specific settings, assembly, and operation modes of the output gear 260, the first transmission component 290, the second transmission component 280, and the elastic member 2010 will be described in detail later. For the sake of brevity, the following description regarding Figure 2 - Figure 8 will only be elaborated on for one differential housing 210 and its internal structure.

[0095] Referring to Figure 2 and Figure 3 , each housing half 211 includes a shaft hole 2111 for passing through the axle 100 and an annular mounting base 2113 for docking with the internal gear ring. The mounting base 2113 further has a mounting base protrusion 2115 extending axially inward. Corresponding to this, an external gear ring groove 232 is provided on the external gear ring 230 (see Figure 6A ). When the mounting base protrusion 2115 is inserted into the external gear ring groove 232, bolts 240 (see Figure 2 ) can be used to lock the pair of housing halves 211 and the external gear ring 230 at this position, so that the pair of housing halves 211 and the external gear ring 230 can rotate as a whole. The circumferential external teeth 231 on the external gear ring 230 are used to mesh with the power source of the differential 200, so that the differential 200 can rotate driven by this power source. Referring to Figure 1C and Figure 6A , a plurality of planet gears 250 are mounted on the radial inner side of the external gear ring 230. The self-rotation axis 251 of each planet gear 250 extends in the radial direction. Specifically, referring to Figure 1D , an assembly center member 233 for assembling the planet gears 250 is further provided at the central part of the differential 200. A self-rotation axis mounting hole 2331 extending in the radial direction is formed on the assembly center member 233. The self-rotation axes 251 of the respective planet gears 250 are inserted into the self-rotation axis mounting holes 2331. The plurality of planet gears 250, the external gear ring 230, and the assembly center member 233 at least partially together constitute a planetary gear system 221. The axial inner end 102 of the axle 100 (see Figure 1E ) extends and inserts into the assembly center member 233.

[0096] In some embodiments, the external gear ring 230, the planet gears 250, and the differential housing 210 at least partially constitute the input mechanism 220 of the differential 200, and the output gear 260 at least partially constitutes the output mechanism of the differential 200. The output gear 260 has internal teeth 265 axially penetrating therethrough. The keyway 101 of the axle 100 (see Figure 1E) and is bonded to the internal teeth 265 so as to be fixed in the rotational direction relative to the output gear 260. The rotation of the input mechanism 220 about the axis is transmitted to the output gear 260, and the output gear 260 then transmits the rotational motion to the axle 100, thus completing the transmission of motion.

[0097] It should be noted that the "composition" mentioned in the present invention should be understood as an open description rather than a closed description. For example, the input mechanism 220 of the present invention may also include other components in addition to the external gear ring 230, the planetary gears 250, and the differential housing 210; the output mechanism may also include other components in addition to the output gear 260; the planetary gear system 221 may include other components in addition to the external gear ring 230 and the plurality of planetary gears 250.

[0098] The input mechanism 220 can provide power input to the output gear 260 at two positions. That is to say, the input mechanism 220 has two input ends that can be engaged with the output gear 260 respectively. The output gear 260 is located between the two input ends. Specifically, the main input end of the input mechanism 220 may include the planetary gears 250, and the auxiliary input end of the input mechanism 220 may include the differential housing 210. The motion output modes of the main input end and the auxiliary input end to the output gear 260 will be discussed separately below.

[0099] When there is no differential on the left and right sides of the differential 200, the rotation of the external gear ring 230 drives the revolution of the plurality of planetary gears 250, and the planetary gears 250 are engaged with the axial inner end teeth 261 of the output gear 260 to drive the output gear 260 to rotate. The axial inner end teeth 261 of the planetary gears 250 and the output gear 260 may both be bevel gears. During this process, the planetary gears 250 do not rotate on their own axes. Therefore, the two output gears 260 located on the left and right sides of the external gear ring 230 have the same rotational speed and direction of rotation. Then, the axles 100 on the left and right sides of the differential 200 are driven by the differential 200 to rotate in the same direction at the same rotational speed as the differential 200. In the case of no differential, the differential 200 only plays a role in motion transmission.

[0100] When the movable power tool turns or one of its tires gets stuck in an area with abnormal resistance such as mud or ice and snow, differential may occur on both sides of the differential 200. At this time, the reduction in the rotational speed of one side of the axle 100 will cause the planetary gear 250 to rotate on its own axis, resulting in a speed difference between the output gears 260 on both sides of the external gear ring 230. In such a case, the output gear 260 fixed to the axle 100 in the rotational direction may disengage from the planetary gear 250, which causes the motion input from the main input end of the input mechanism 220 to the output gear 260 to fail. If there is no other input source, then this side of the axle 100 will not be able to continue rotating. To solve this problem, when the meshing between the main input end and the output gear 260 fails, the auxiliary output end of the input mechanism 220 can play a role and continue to output motion to the output gear 260.

[0101] Refer to 1B and Figure 3 , the transmission of motion from the differential housing 210 to the output gear 260 is achieved through the first transmission component 290 and the second transmission component 280. The first transmission component 290 and the second transmission component 280 are annular sheet-like structures that are substantially perpendicular to the axis and surround the axis. For example, they can be ratchet sheets. The output gear 260 may include an axially outer segment 264 and an axially inner segment 263 formed as one body, and the outer diameter of the axially outer segment 264 is smaller than the outer diameter of the axially inner segment 263. Refer to Figure 4 , Figure 6A and Figure 6B , an output gear bonding protrusion 262 is formed on the axially outer segment 264 of the output gear 260, and a first transmission component bonding groove 291 is provided at the corresponding position on the first transmission component 290. The output gear bonding protrusion 262 and the first transmission component bonding groove 291 cooperate with each other to assemble the first transmission component 290 and the output gear 260 together.

[0102] Refer to Figure 4 and Figure 5 , the second transmission component 280 is assembled on the inner wall of the differential housing 210. Figure 5 It is a view of the housing half 211 of the left half of the differential, which is observed from the perspective from the axial center towards the axial outside, that is, from the right to the left perspective for this housing half 211. For example, a housing bonding protrusion 2114 is provided on the inner surface of the axial end wall of the differential housing 210, and a second transmission component bonding groove 281 is provided at the corresponding position of the second transmission component 280. The housing bonding protrusion 2114 and the second transmission component bonding groove 281 cooperate with each other to make the second transmission component 280 and the differential housing 210 fixed relative to each other in the rotational direction. A gasket 270 can also be provided between the second transmission component 280 and the differential housing 210.

[0103] Refer toFigure 1B , Figure 1E , Figure 3 and Figure 4 , the first conductive member 290 and the second conductive member 280 face each other and both surround the axial outer segment 264. When the engagement between the output gear 260 and the main input mechanism 220 fails, the first conductive member 290 and the second conductive member 280 engage, and in this engaged state, the second conductive member 280 drives the first conductive member 290 to rotate in a predetermined direction. In some embodiments, the second conductive member 280 has a protrusion 282 facing the first conductive member 290, and the first conductive member 290 has a recess 292 facing the second conductive member 280. In the engaged state, the protrusion 282 can be located within the recess 292 so that the protrusion 282 can abut against the circumferential inner wall of the recess 292 to drive the first conductive member 290 to rotate. The state in which the protrusion 282 of the second conductive member 280 falls into the recess 292 of the first conductive member 290 is shown in Figure 8 .

[0104] Preferably, the circumferential dimension of the recess 292 is larger than the circumferential dimension of the protrusion. Such a setting allows a certain rotational movement relative to each other when the first conductive member 290 and the second conductive member 280 are in the engaged state. Also preferably, the protrusion 282 has an inclined surface 283, and the end wall of the recess 292 has an inclined surface 294. The protrusion 282 and the recess 292 are engaged through the inclined surfaces to facilitate the protrusion to disengage from or enter the recess 292. Such a setting enables the movement input of the second conductive member 280 to the first conductive member 290 to be intermittent. For example, after the protrusion abuts against the wall of the recess 292 and rotates for a certain time, the protrusion can disengage from the recess 292 through the inclined surface. Subsequently, the second conductive member 280 rotates a certain angle relative to the first conductive member 290 in a predetermined direction. After that, the protrusion enters the next recess 292 again through the inclined surface and abuts against the wall of the recess 292 to drive the first conductive member 290 to rotate again.

[0105] That is to say, as long as the second transmission member 280 can perform a motion input on the first transmission member 290, even if it is an intermittent motion input, the first transmission member 290 and the second transmission member 280 are in an engaged state. As described above, in this engaged state, it is not required that the protrusion 282 of the second transmission member 280 continuously remains within the recess 292 of the first transmission member 290, nor is it required that the inclined surface 294 of the recess 292 and the inclined surface 283 of the protrusion 282 continuously abut. In some other embodiments, when the second transmission member 280 and the first transmission member 290 are in an engaged state, they may rotate synchronously. For example, the protrusion 282 of the second transmission member 280 may continuously remain within the recess 292 of the first transmission member 290, and / or the inclined surface 294 of the recess 292 and the inclined surface 283 of the protrusion 282 continuously abut.

[0106] In some embodiments, the first transmission member 290 and the output gear 260 may be fixed to each other only in the rotational direction, but may be slightly displaced relative to each other in the axial direction. For example, there may be an axial gap 2011 (see Figure 8 ) between the first transmission member 290 and the axial inner section 263 of the output gear 260, and an annular elastic member 2010 may be installed at the axial gap 2011. When the output gear 260 is disengaged from the planetary gear 250, the output gear 260 will move axially outward, and this axially outward movement will squeeze the elastic member 2010, causing the elastic member 2010 to also axially outwardly squeeze the first transmission member 290 to facilitate the engagement of the first transmission member 290 and the second transmission member 280. When the protrusion 282 of the second transmission member 280 enters the recess of the first transmission member 290 (i.e., the axial spacing between the two is reduced), the elastic member 2010 will rebound towards its original state. In addition, even when the auxiliary input end and the output gear 260 are engaged, due to the elastic member 2010 having a certain elastic force, the elastic member 2010 will still continuously axially inwardly push the output gear 260 to facilitate the output gear 260 to resume meshing with the planetary gear 250 as soon as possible. That is to say, in some embodiments, regardless of whether the first transmission member 290 and the second transmission member 280 are in an engaged state, the elastic member 2010 has a certain elastic force.

[0107] In Figure 1BIn the transient state shown, the first conduction member 290 and the second conduction member 280 on the right side of the outer gear ring can be in an engaged state, for example, and at this time, the protrusion 282 of the second conduction member 280 is located in the recess of the first conduction member 290; the first conduction member 290 and the second conduction member 280 on the left side of the outer gear ring can be in a disengaged state, or when in an engaged state, the relative rotation of the first conduction member 290 and the second conduction member 280 just reaches a state where the protrusion 282 of the second conduction member 280 is located outside the recess of the first conduction member 290. In Figure 1E As shown, when the protrusion 282 of the second conduction member 280 is located within the recess of the first conduction member 290, the compression amount of the elastic member 2010 (such as the right elastic member 2010b) is less than the compression amount of the elastic member 2010 (such as the left elastic member 2010a) when the protrusion 282 of the second conduction member 280 is located outside the recess of the first conduction member 290. That is to say, compared with the left elastic member 2010a, the right elastic member 2010b is closer to its original state.

[0108] When the main input end moves and outputs to the output gear 260, the auxiliary input end may not function as a motion input to the output gear 260. The positional relationship between the first conduction member 290 and the second conduction member 280 in this state is shown in Figure 7 Shown. Referring to Figure 4 And Figure 7 , the first conduction member 290 has a base section 293 in addition to the recess 292, and the base section 293 protrudes axially relative to the recess 292. When the first conduction member 290 and the second conduction member 280 are not engaged, the protrusion 282 of the second conduction member 280 abuts against the base section 293 of the first conduction member 290. Of course, even if the second conduction member 280 does not transmit motion to the first conduction member 290, the first conduction member 290 and the second conduction member 280 still rotate together.

[0109] The present invention also has some other preferred settings. For example, referring back to Figure 2 , the differential housing 210 has a structure adapted to the shape of the output gear 260. For example, corresponding to the stepped axial inner section 263 and the axial outer section 264 of the output gear 260, the middle section 2112 of the differential housing 210 can also have a similar stepped configuration.

[0110] In other embodiments not shown, the present invention may also have other settings. For example, the main input end of the input mechanism may be other types of gears other than planetary gears; the auxiliary input end of the input mechanism does not necessarily have to be the differential housing, and there may be another component fixed relative to the outer tooth width (which meshes with the power source of the differential) as the auxiliary input end; the cooperation between the first transmission component and the second transmission component does not necessarily have to be achieved through the cooperation of protrusions and recesses, and the first transmission component and the second transmission component may have other cooperation relationships such as meshing and snap fit; the first transmission component and the second transmission component do not necessarily have to be in an annular sheet structure, and the two of them may have other configurations such as plate-shaped and block-shaped.

[0111] The present invention also provides a portable power tool, an example of which is shown in Figure 9 . Figure 9 The gardening tool shown in is a lawn mower 320. In other embodiments, the portable power tool may also be a snow blower. Figure 9 The lawn mower 320 shown in is a four-wheel power tool, which includes a pair of rear wheels 321 and a pair of front wheels 322. In particular, it may also include a handle 323 for the operator to hold to manipulate and push the power tool. Figure 1A - Figure 8 The differential shown can be used to connect between a pair of rear wheels 321 to provide a differential function between the pair of rear wheels when a certain rear wheel of the lawn mower 320 slips or idles. The axles 100 on both sides of the differential 200 can be respectively the input components of a pair of rear wheels 321 of the lawn mower 320. For example, they can be respectively the axles of a pair of rear wheels 321 of the lawn mower 320, or can be connected to the axles of a pair of rear wheels 321 of the lawn mower 320 through a transmission or the like. The above description of the embodiments of the differential should also be considered as a description of the embodiments of the portable power tool.

[0112] Through the discussion of the above embodiments, it can be known that the differential of the present invention enables the input component to provide power input to the output component at two positions. Once the motion input from the main input end to the output component fails, the auxiliary input end will act on the output component to continue to provide motion input to the output component, and the output component can still rotate with the input component. Therefore, the differential provided by the present invention can ensure the effectiveness and stability of motion transmission and reduce the occurrence of slip phenomena. Further, in some aspects of the present invention, the disengagement between the main input end and the output component can promote the engagement between the auxiliary input end and the output component, thereby further improving the stability and effectiveness of motion transmission, and further reducing the probability of slip phenomena occurring.

[0113] From the above, those skilled in the art can easily recognize that alternative structures of the structures disclosed in the present invention can be used as feasible alternative embodiments, and the embodiments disclosed in the present invention can be combined to produce new embodiments, which also fall within the scope of the appended claims.

Claims

1. A differential for a movable electric tool, the differential (200) being configured to drive axles (100) mounted on its left and right sides to rotate about the axis (X) of the axles, characterized in that, The differential includes: An input mechanism (220), the input mechanism including a main input end (250) and an auxiliary input end (210) that rotate integrally about the axis; An output gear (260), the output gear and the axle (100) being fixedly engaged in the rotational direction, and the output gear being located between the main input end and the auxiliary input end, wherein the output gear (260) can mesh with the main input end (250); A first transmission member (290), the first transmission member being fixedly connected to the output gear (260) in the rotational direction; A second transmission member (280), the second transmission member being fixedly connected to the auxiliary input end (210) in the rotational direction, wherein the first transmission member (290) and the second transmission member (280) face each other, and when the meshing between the output gear (260) and the main input end (250) fails, the first transmission member (290) and the second transmission member (280) engage, and in this engaged state, the second transmission member (280) drives the first transmission member (290) to rotate in a predetermined direction.

2. The differential according to claim 1, wherein, There is an axial displacement gap (2011) between the first transmission member (290) and the output gear (260), and an elastic member (2010) is provided at the axial displacement gap. When the meshing between the output gear (260) and the main input end (250) fails, the output gear (260) presses the elastic member (2010) so that the first transmission member (290) engages with the second transmission member (280) under the elastic force of the elastic member. Preferably, the elastic member (2010) is in a compressed state both when the first transmission member (290) and the second transmission member (280) are in the engaged and non-engaged states.

3. The differential according to claim 1, characterized in that, The first transmission member (290) and the second transmission member (280) form an annular sheet-like structure that is substantially perpendicular to the axis and surrounds the axis. The second transmission member (280) has a protrusion (282) facing the first transmission member, and the first transmission member (290) has a recess (292) facing the second transmission member. In the engaged state, the protrusion (282) can be located within the recess (292), and the circumferential dimension of the recess (292) is larger than the circumferential dimension of the protrusion (282). Preferably, the protrusion and the recess are engaged through inclined surfaces (283, 294) to facilitate the protrusion to disengage from or enter the recess.

4. The differential according to any one of claims 1-3, characterized in that, The input mechanism (220) includes: A differential housing (210), wherein the differential housing constitutes the auxiliary input end; A planetary gear system (221) located at the axial center position of the differential housing (210), the planetary gear system (221) including: An outer gear ring (230) for receiving an external motion input; A plurality of planetary gears (250) installed radially inside the external gear ring (230), and the plurality of planetary gears constitute the main input end.

5. The differential according to claim 4, characterized in that, The differential housing (210) includes a pair of housing halves (211) axially butted together, and the external gear ring (230) is at least partially fixed between the pair of housing halves.

6. The differential according to claim 4, characterized in that, The plurality of planetary gears (250) are bevel gears, and the self-rotation axis (251) of each planetary gear (250) extends in the radial direction, and the axially inner end teeth (261) of the input gear (260) are also correspondingly formed as bevel gears.

7. The differential according to claim 6, characterized in that, The differential further includes a central fitting (233) located at its center. Among them, the radially outer end of each self-rotation axis (251) is inserted into the corresponding receiving hole of the external gear ring (230), and the radially inner end of each self-rotation axis (251) is inserted into the self-rotation axis mounting hole (2331) of the central fitting. Preferably, the axially inner end (102) of the axle (100) is inserted into the corresponding receiving hole of the central fitting (233).

8. The differential according to any one of claims 1-7, characterized in that, The output gear (260) includes an axially outer segment (264) and an axially inner segment (263) formed integrally. The outer diameter of the axially outer segment (264) is smaller than the outer diameter of the axially inner segment (263), and both the first transmission member (290) and the second transmission member (280) surround the axially outer segment (264). In particular, the axle (100) penetrates through the entire input gear (260) and engages with the inner teeth (265) of the input gear.

9. The differential according to claim 8, wherein The differential housing (210) of the differential has a stepped structure adapted to the shape of the output gear (260).

10. The differential according to any one of claims 1-9, characterized in that, The first transmission member (290) is fixedly bonded to the output gear (260), and / or the second transmission member (280) is fixedly bonded to the auxiliary input end (210).

11. A movable electric tool, characterized in that, The portable power tool includes the differential according to any one of claims 1-10 and axles installed on the left and right sides of the differential.

12. The movable electric tool according to claim 11, characterized in that, The portable power tool is a lawn mower (320) or a snow blower.

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