A combined gearbox

Abstract

The present invention discloses a combined gearbox, comprising an input module, a speed change module, an output module and a housing, wherein the speed change module comprises a driving shaft, a driven shaft and a shift mechanism, wherein the driving shaft is sleeved with a first gear, a second gear, a third gear and a fourth gear in sequence along the axial direction, and the driven shaft is sleeved with a fifth gear, a sixth gear, a seventh gear and an eighth gear meshed with corresponding gears on the driving shaft in sequence along the axial direction; the shift mechanism is engaged with a first annular groove on the third gear and a second annular groove on the sixth gear; a first transmission member, a second transmission member, a third transmission member and a fourth transmission member are respectively arranged between the third gear and the second gear and the fourth gear, and a sixth transmission member, a fifth transmission member, an eighth transmission member and a seventh transmission member are respectively arranged between the sixth gear and the fifth gear and the seventh gear. The combined gearbox of the present invention provides more speed options, has a compact and simple structure, can shift gears as needed without disassembly, and is convenient and reliable in speed change.

Description

Technical Field

[0001] The present invention relates to the field of transmission technology, and more specifically, to a combined gearbox. Background Art

[0002] In daily production work, due to the influence of various factors such as wood material, thickness, required processing shape, tool cutting depth, etc., in order to obtain the required speed segment and meet the more refined speed requirements required for processing, the feeder generally needs at least 8 gears. Under the factory-set gear ratio of ordinary feeders, only the gear of the motor (fast and slow) can be directly adjusted. If you want to get a speed other than the factory-set gear ratio, you need to remove the protective back cover of the feeder and remove the transmission components, replace the gears with the new gear ratio, and then reinstall all the components to get the new speed. If the speed obtained by the new gear ratio does not meet the actual production requirements, you need to repeat the above disassembly and assembly steps, which is time-consuming and labor-intensive. Frequent disassembly and assembly will increase maintenance costs and greatly affect the life of feeder components. There is a large amount of lubricating grease at the gear meshing position. The grease is very easy to leak during the disassembly and shifting process, causing pollution to the working environment. Because the processing and production environment of the feeder is mostly a wood finishing site, if the wood is contaminated by grease, it cannot enter the next process normally. In addition, if the old grease is not properly handled, it will cause great environmental pollution. Refilling grease after disassembly will also incur additional costs. The disassembly and assembly process also requires certain professional technical requirements. If the operation is improper, it will leave safety hazards. Disassembly and assembly requires professional tools, and the disassembly and assembly of parts is cumbersome, which greatly affects efficiency.

[0003] In order to meet the need of shifting gears without disassembly, a gearbox is needed to be matched with the feeder to meet this requirement. The gearboxes used on the feeder on the market generally adopt the gear shifting method of meshing and disengaging between different levels of two-stage tower gears. There are only two gears, which cannot meet the 8-speed requirement of the feeder. It can only reach four gears with the motor fast and slow gears. The remaining gears still need to be disassembled and replaced to switch. And when the gears are shifted, there will be disadvantages such as tooth hitting, meshing failure, and poor gear shifting. The four-speed combination gearbox with the same shifting method is extremely complex, occupies a large space, and still has disadvantages such as tooth hitting, meshing failure, and poor gear shifting. It is not suitable for use with the feeder itself, which is not large in size.

[0004] The prior art combined gearbox, such as the invention patent CN104373532A disclosed on February 25, 2005, describes a pure mechanical four-speed gearbox for electric vehicles. The sliding sleeve teeth sliding on different shafts and different gears are driven to provide four optional speed gears. If it can be used on a feeder, the segmentation of the feeding speed can be further refined, which can meet the user's fine demand for the speed segment of the feeder. It can shift gears without disassembly and assembly, and the speed change is convenient and fast, further improving the efficiency of the speed change. However, the disadvantage of this variable ratio coaxial combined gearbox is that the overall structure is huge and bloated, occupies a large space, and one of the gears is a free state (i.e., neutral) without a speed ratio, no engagement and no restrictions, and can actually only provide three groups of different speed ratios (i.e., three actual gears). In addition, the four-speed gearbox can only shift gears in a sequential forward or sequential backward manner, and cannot be randomly combined and shifted. Therefore, it cannot be applied to the feeder to meet the needs of 4-speed shifting. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a combined gearbox, which provides more speed range options, has a compact and simple structure, can be shifted as needed without disassembly, and has convenient and reliable speed change.

[0006] The technical problem solved by the present invention is achieved by adopting the following technical scheme: a combined gearbox, comprising an input module, a speed change module, an output module and a housing, wherein the speed change module is installed in the housing, wherein the input module comprises an input worm and a worm wheel, the input worm and the worm wheel are meshed, the speed change module comprises a driving shaft, a driven shaft and a shifting mechanism, the output module is fixedly arranged on the driven shaft, the worm wheel is fixedly arranged on the driving shaft, and the driving shaft is parallel to the driven shaft; the driving shaft is sequentially sleeved with a first gear fixed relative to the driving shaft, a second gear which can only rotate relative to the driving shaft, a third gear which can only slide axially relative to the driving shaft and rotate with the driving shaft, and a fourth gear which can only rotate relative to the driving shaft, and the driven shaft is sequentially sleeved with a fifth gear which can only rotate relative to the driven shaft, and a sixth gear which can only slide axially relative to the driven shaft and rotate with the driven shaft along the axial direction. , the seventh gear which can only rotate relative to the driven shaft, and the eighth gear which is fixed relative to the driven shaft; the first gear and the fifth gear, the second gear and the sixth gear, the third gear and the seventh gear, the fourth gear and the eighth gear, each group of two gears are meshed with each other and the tooth number ratio is unequal; the third gear is provided with a first annular groove, the sixth gear is provided with a second annular groove, and the shifting mechanism is engaged with the first annular groove and the second annular groove; the first transmission member and the second transmission member which can be nested with each other are respectively arranged on the relative end surfaces of the third gear and the second gear, the third transmission member and the fourth transmission member which can be nested with each other are respectively arranged on the relative end surfaces of the third gear and the fourth gear, the sixth transmission member and the fifth transmission member which can be nested with each other are respectively arranged on the relative end surfaces of the sixth gear and the fifth gear, and the eighth transmission member and the seventh transmission member which can be nested with each other are respectively arranged on the relative end surfaces of the sixth gear and the seventh gear.

[0007] In the combined gearbox of the present invention, the first gear is fixedly connected and installed with the driving shaft, and the fifth gear on the corresponding meshing driven shaft is rotatable relative to the driven shaft but is limited in sliding along the axial direction; the second gear on the driving shaft is rotatable relative to the driving shaft but is limited in sliding along the axial direction, and the sixth gear on the corresponding meshing driven shaft can only slide along the axial direction but cannot rotate relative to the driven shaft; the third gear on the driving shaft can only slide along the axial direction but cannot rotate relative to the driving shaft, and the seventh gear on the corresponding meshing driven shaft is rotatable relative to the driven shaft but is limited in sliding along the axial direction; the fourth gear on the driving shaft is rotatable relative to the driving shaft but is limited in sliding along the axial direction, and the eighth gear on the corresponding meshing driven shaft is fixedly connected and installed with the driven shaft.

[0008] The shift mechanism is engaged with the first annular groove of the third gear and the second annular groove of the sixth gear, driving the third gear and the sixth gear to slide axially. The first transmission member and the second transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the third gear and the second gear, the third transmission member and the fourth transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the third gear and the fourth gear, the sixth transmission member and the fifth transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the sixth gear and the fifth gear, and the eighth transmission member and the seventh transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the sixth gear and the seventh gear. When the third gear slides to the point where the first transmission member and the second transmission member are nested and the third transmission member and the fourth transmission member are disengaged, it is the first positive position, when the third gear slides to the point where the first transmission member and the second transmission member are disengaged and the third transmission member and the fourth transmission member are disengaged, it is the first zero position, and when the third gear slides to the point where the third transmission member and the fourth transmission member are nested and the first transmission member and the second transmission member are disengaged, it is the first negative position. When the sixth gear slides to the point where the sixth transmission member is nested with the fifth transmission member and the eighth transmission member is disengaged from the seventh transmission member, it is the second positive position; when the sixth gear slides to the point where the sixth transmission member is disengaged from the fifth transmission member and the eighth transmission member is disengaged from the seventh transmission member, it is the second zero position; when the sixth gear slides to the point where the eighth transmission member is nested with the seventh transmission member and the sixth transmission member is disengaged from the fifth transmission member, it is the second negative position.

[0009] The power is input from the input worm of the input module, the worm gear meshes with the input worm gear, and the worm gear and the driving shaft are driven to rotate around the axis as a whole. Therefore, the first gear rotates at the same speed as the driving shaft, and the first gear meshes with the fifth gear, so the first gear drives the fifth gear to rotate. At this time, the sixth gear is in the second positive position, and the third gear is in the first zero position. The sixth transmission member on the sixth gear is nested with the fifth transmission member on the fifth gear, so the fifth gear drives the sixth gear to rotate at the same speed, and the sixth gear and the driven shaft rotate at the same speed as a whole. The output module on the driven shaft outputs the speed. At this time, it is the first speed change output mode (first gear). When the third gear is in the first positive position and the sixth gear is in the second zero position, the driving shaft drives the third gear to rotate, and the first transmission member on the third gear is nested with the second transmission member on the second gear, so the third gear drives the second gear to rotate at the same speed, and the second gear and the sixth gear mesh, so the second gear drives the sixth gear to rotate, and the sixth gear and the driven shaft rotate at the same speed as a whole. The output module on the driven shaft outputs the speed, and at this time, it is the second speed change output mode (second gear). When the sixth gear is in the second negative position and the third gear is in the first zero position, the driving shaft drives the third gear to rotate, the third gear and the seventh gear are meshed, so the third gear drives the seventh gear to rotate, the eighth transmission member on the sixth gear is nested with the seventh transmission member on the seventh gear, so the seventh gear drives the sixth gear to rotate at the same speed, the sixth gear and the driven shaft rotate at the same speed, and the output module on the driven shaft outputs the speed. At this time, it is the third speed change output mode (third gear). When the third gear is in the first negative position and the sixth gear is in the second zero position, the driving shaft drives the third gear to rotate, the third transmission member on the third gear and the fourth transmission member on the fourth gear are nested, so the third gear drives the fourth gear to rotate at the same speed, the fourth gear and the eighth gear are meshed, so the fourth gear drives the eighth gear to rotate, the eighth gear and the driven shaft rotate at the same speed, and the output module on the driven shaft outputs the speed. At this time, it is the fourth speed change output mode (fourth gear). The gear ratios of the four pairs of gears, namely the first gear and the fifth gear, the second gear and the sixth gear, the third gear and the seventh gear, and the fourth gear and the eighth gear, are not equal to each other. The combined gearbox provides four speed gears to meet more precise speed requirements. The gear shifting operation can be performed without disassembling the box, and the gear switching is convenient and fast. The combined gearbox also adopts the transmission parts nesting and disengaging combination selection driven speed change. The old gearbox meshing and disengaging speed change usually takes up a lot of space. At the same time, when shifting gears, it is easy to cause tooth collision and tooth collapse before the gears mesh with each other, resulting in damage to the workpiece and uneven speed change. The combined gearbox adopts the transmission parts nesting or disengaging combination selection driven speed change to replace the old gearbox meshing and disengaging speed change mode. It does not need to disengage and re-engage the gears to shift gears, which saves space in structure and has a more compact and simple structure. At the same time, the combination of transmission parts can effectively avoid the disadvantages of the old speed change mode, making the speed change smoother, more convenient and reliable.

[0010] Preferably, the shift mechanism includes a shift shaft, a first shift fork, a second shift fork and a driven member, the shift shaft is parallel to the driven shaft, the first shift fork and the second shift fork are sleeved on the shift shaft, the first shift fork is engaged with the first annular groove, the second shift fork is engaged with the second annular groove, the shift shaft is sequentially provided with a first cylindrical cam groove and a second cylindrical cam groove along the axial direction, the first shift fork and the second shift fork are both provided with driven holes on radial surfaces, and the driven member passes through the driven holes on the first shift fork and the second shift fork respectively and is engaged in the first cylindrical cam groove and the second cylindrical cam groove.

[0011] When the shift shaft starts to rotate, the first shift fork and the second shift fork start to move axially along the trajectory of the first cylindrical cam groove and the second cylindrical cam groove on the shift shaft, and the first shift fork and the second shift fork are engaged with the first annular groove on the third gear and the second annular groove on the sixth gear, thereby driving the third gear and the sixth gear to move axially and complete the required shifting action. The shift shaft provides a lateral positioning function for the first shift fork and the second shift fork, and controls the distance between the first shift fork and the second shift fork and the driving shaft and the driven shaft. At the same time, it provides support for the first shift fork and the second shift fork, so that the first shift fork and the second shift fork can be better nested in the first annular groove and the second annular groove. Since the first shift fork and the second shift fork need to satisfy the relative position relationship between the third gear and the sixth gear when shifting, the trajectory of the first cylindrical cam groove and the second cylindrical cam groove can make the first shift fork and the second shift fork meet the position requirements required for shifting. The driven member allows the first shift fork and the second shift fork to be better positioned on the shift shaft and to be able to perform axial displacement according to a desired trajectory.

[0012] Preferably, the shift mechanism further comprises a clamping member, and the first shift fork and the second shift fork are both provided with clamping grooves at axial positions corresponding to the driven hole, and the clamping member is clamped to the clamping groove and covers the driven hole. The clamping member can effectively prevent the driven member from loosening, so that the first shift fork and the second shift fork can be better positioned on the shift shaft and can be axially displaced according to a desired trajectory.

[0013] Preferably, the first cylindrical cam groove has axial displacement positions of a first positive position, a first zero position and a first negative position relative to the shift shaft, and the second cylindrical cam groove has axial displacement positions of a second positive position, a second zero position and a second negative position relative to the shift shaft, and the axial displacement positions of the first cylindrical cam groove and the second cylindrical cam groove can form a logical self-locking relationship with each other. The first cylindrical cam groove and the second cylindrical cam groove have axial displacement positions that form a logical self-locking relationship with each other, and the axial displacement positions of the first cylindrical cam groove and the second cylindrical cam groove allow the first shift fork and the second shift fork to meet the position requirements required for shifting.

[0014] Preferably, the first transmission member and the second transmission member, the third transmission member and the fourth transmission member, the sixth transmission member and the fifth transmission member, the eighth transmission member and the seventh transmission member, which can be nested with each other, are a number of equally divided concave-convex structures between their end faces, which are mutually nested with each other and have virtual intervals, and when they are mutually nested, they can be restricted from rotating with each other. The first transmission member and the second transmission member, the third transmission member and the fourth transmission member, the sixth transmission member and the fifth transmission member, the eighth transmission member and the seventh transmission member are a number of equally divided concave-convex structures between their end faces, which are mutually nested with each other, and the concave-convex structures have virtual intervals to facilitate the mutual nesting of the concave-convex structures, and when the concave-convex structures are mutually nested, they are restricted from rotating with each other.

[0015] In one embodiment, the end of the shift shaft is fixedly provided with a positioning plate and a shift knob in sequence along the axial direction, a support hole is provided on the end face of the housing near the end of the shift shaft, a spring plunger is provided in the support hole, and a positioning hole is provided on the end face of the positioning plate facing the housing, and the spring plunger can be inserted into the positioning hole. A spring plunger is fixedly installed in the support hole, and a steel ball of the spring plunger abuts against the positioning hole set by the positioning plate to locate the rotation position of the shift shaft. When the shift shaft is rotated, the steel ball escapes from the positioning hole and abuts against the end face of the positioning plate, and the shift shaft continues to be rotated to the next speed change output mode (i.e., the next gear position), and the positioning hole set by the positioning plate continues to align with the spring plunger, and the steel ball is again inserted into the positioning hole for positioning, so that the desired gear position can be selected at will. In this way, the alignment of the rotation position of the shift shaft after the gear shift can be ensured, and the accuracy of the lateral position of the first shift fork and the second shift fork when the desired gear position is reached can be ensured.

[0016] In one embodiment, the third gear is key-connected to the driving shaft, and the third gear can slide axially relative to the driving shaft but cannot rotate relative to the driving shaft, and the sixth gear is key-connected to the driven shaft, and the sixth gear can slide axially relative to the driven shaft but cannot rotate relative to the driven shaft. The key connection between the third gear and the driving shaft can enable the third gear to slide axially along the driving shaft, and can transmit the rotation speed of the driving shaft to the third gear through the key connection. The key connection between the sixth gear and the driven shaft can enable the sixth gear to slide axially along the driving shaft, and can transmit the rotation speed of the sixth gear to the driven shaft through the key connection.

[0017] In one embodiment, the output module includes an output component, the end of the driven shaft toward the box cover protrudes from the box cover, and the output component is installed on the end protruding from the box cover. The speed of the driven shaft after the speed change is output through the output component, and the output component is arranged at the end protruding from the box cover and outside the box body, so that it is convenient to use other transmission components on the output component, and the output component can be used as output power to drive other components.

[0018] In one embodiment, the box body includes a shell, a box cover and a positioning screw. The shell and the box cover are provided with positioning pin holes, and the positioning screws with positioning pins are inserted into the positioning pin holes for positioning and tightening. The box body can be composed of the shell and the box cover, which is convenient for disassembly and maintenance. The positioning screws with positioning pins pass through the positioning pin holes to press the shell and the box body together and can accurately position the shell and the box cover in the horizontal direction.

[0019] Compared with the prior art, the invention has the following beneficial effects: it provides more speed range options, has a compact and simple structure, can shift gears as needed without disassembly, and is more convenient and reliable in speed change. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a feeder with a combined gearbox;

[0021] Figure 2 It is a partial cross-sectional schematic diagram of a combined gearbox;

[0022] Figure 3 It is a schematic diagram of the internal structure of the combined gearbox;

[0023] Figure 4 It is the exploded assembly diagram of the combined gearbox;

[0024] Figure 5 A schematic diagram of gear selection for a combined transmission;

[0025] Figure 6 It is a schematic diagram of the shift mechanism of the combined transmission.

[0026] The drawings are only used for illustrative purposes and are not to be construed as limitations of the present invention. To better illustrate the embodiments, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific implementation modes and drawings, but the specific embodiments do not limit the present invention in any way.

[0028] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the combined gearbox 100 includes an input module 10 (a motor in this embodiment), a speed change module 20, an output module 30 and a housing 50. Figure 4As shown, the housing 50 is composed of a shell 510 and a cover 530, and a sealing gasket 520 is provided at the joint plane between the shell 510 and the cover 530. A positioning pin hole 532 is provided on the shell 510 and the cover 530, a fixing hole 533 is provided on the cover 530, and a threaded hole is provided at the corresponding position of the shell 510; a positioning screw (for example, a shoulder screw) 550 with a positioning pin rod passes through the positioning pin hole 532 and a screw 540 passes through the fixing hole 533 to lock, press and laterally position the shell 510 and the cover 530. The input worm 110 is arranged in the shell 510. There are three parallel driving shafts 210, driven shafts 310 and shift shafts 410 in the housing 50. The first gear 230, the second gear 240, the third gear 250 and the fourth gear 260 are sequentially sleeved on the driving shaft 210 along the axial direction, and the fifth gear 330, the sixth gear 340, the seventh gear 350 and the eighth gear 360 are sequentially sleeved on the driven shaft 310 along the axial direction. The first gear 230 is meshed with the fifth gear 330, the second gear 240 is meshed with the sixth gear 340, the third gear 250 is meshed with the seventh gear 350, and the fourth gear 260 is meshed with the eighth gear 360.

[0029] like Figure 4As shown, starting from the axial direction, the first gear 230 on the driving shaft 210 is fixedly connected to the driving shaft 210 by a key (a key-fixed connection in the present embodiment) and is installed at the first step 211, and the corresponding fifth gear 330 on the driven shaft 310 that is meshed is installed at the sixth step 311 on the driven shaft 310, and the fifth gear 330 can rotate relative to the driven shaft 310 but is limited in axial sliding; the second gear 240 on the driving shaft 210 is installed at the third step 213, and the second gear 240 can rotate relative to the driving shaft 210 but is limited in axial sliding, and the corresponding sixth gear 340 on the driven shaft 310 that is meshed is installed at the seventh step 312. In this embodiment, the seventh step 312 of the driven shaft 310 is a spline shaft, and the inner hole of the sixth gear 340 is an inner spline hole. The spline shaft and the inner spline hole cooperate with each other so that the sixth gear 340 can only slide axially but not rotate relative to the driven shaft 310; the third gear 250 on the driving shaft 210 is installed at the fourth step 214. In this embodiment, the fourth step 214 is a spline shaft, and the inner hole of the third gear 250 is an inner spline hole. The spline shaft and the inner spline hole cooperate with each other so that the third gear 250 can only slide axially relative to the driving shaft 210 The seventh gear 350 on the corresponding meshing driven shaft 310 is installed at the eighth step 313, and the seventh gear 350 can only rotate relative to the driven shaft 310 but is limited in axial sliding; the fourth gear 260 on the driving shaft 210 is installed at the fifth step 215, and the fourth gear 260 can rotate relative to the driving shaft 210 but is limited in axial sliding, and the eighth gear 360 on the corresponding meshing driven shaft 310 is installed at the ninth step 314 with the driven shaft 310 through a fixed connection (a key fixed connection in this embodiment).

[0030] like Figure 4 and Figure 6As shown, the speed change module 20 includes a shift mechanism 40, and the shift mechanism 40 includes a shift shaft 410, a first shift fork 460, a second shift fork 440 and a follower 450. A first cylindrical cam groove 411 and a second cylindrical cam groove 412 with regular axial displacement are provided at intervals in the middle of the radial surface of the shift shaft 410. One end of the first shift fork 460 and the second shift fork 440 are respectively a first sleeve 461 and a second sleeve 441, and the other ends of the first shift fork 460 and the second shift fork 440 are respectively a first fork end 462 and a second fork end 442 in the shape of a semicircular open fork. The first sleeve 461 of the first shift fork 460 and the second sleeve 441 of the second shift fork 440 are respectively sleeved on the first cylindrical cam groove 411 and the second cylindrical cam groove 412 on the shift shaft 410. The radial surfaces of the first sleeve 461 and the second sleeve 441 are correspondingly provided with driven holes 464, 444, which penetrate from the outer walls of the first sleeve 461 and the second sleeve 441 to the inner walls, and the driven parts 450 are placed in the driven holes 464, 444, and the driven parts 450 corresponding to the first shift fork 460 and the second shift fork 440 are inserted into the corresponding first cylindrical cam groove 411 and the second cylindrical cam groove 412, so that the first shift fork 460 and the second shift fork 440 respectively change with the axial displacement of the first cylindrical cam groove 411 and the second cylindrical cam groove 412, thereby driving the third gear 250 and the sixth gear 340 to generate axial displacement accordingly. The third gear 250 and the sixth gear 340 are provided with a first annular groove 251 and a second annular groove 341 respectively. The first fork end 462 of the first shift fork 460 is clamped in the first annular groove 251 of the third gear 250, and the third gear 250 is pulled to slide axially without hindering its rotation. The second fork end 442 of the second shift fork 440 is clamped in the second annular groove 341 of the sixth gear 340, and the sixth gear 340 is pulled to slide axially without hindering its rotation. A through hole 465 is provided in the middle of the first shift fork 460 to avoid interference between the driven shaft 310 and the gears on the driven shaft 310. The diameter of the through hole 465 is larger than the tooth top circle of the seventh gear 350. The first sleeve 461 and the second sleeve 441 are respectively provided with a first clamping groove 463 and a second clamping groove 443 at the positions corresponding to the driven holes 464 and 444. The shift mechanism 40 further comprises a clamping member 430 which is clamped on the first clamping groove 463 and the second clamping groove 443 to restrict the driven member 450 from coming out.

[0031] like Figure 4 and Figure 5As shown, the positioning plate 570 installed on the shift shaft 410 has four positioning holes 571 evenly distributed on the circumference of the end surface facing the box cover 530. On the end surface of the box cover 530, two support holes 531 are symmetrically provided at 180 degrees concentric with the shift shaft 410. Two spring plungers 560 are fixedly installed in the support holes 531. The steel balls of the spring plungers 560 abut against the positioning holes 571 provided on the positioning plate 570 to position the shift shaft 410. When the shift shaft 410 is rotated, the steel balls fall out of the positioning holes 571 and abut against the end surface of the positioning plate 570. The shift shaft 410 continues to be rotated to the next gear. The positioning holes 571 provided on the positioning plate 570 are aligned with the spring plungers 560 again, and the steel balls are again inserted into the positioning holes 571 for positioning. The positioning plate 570 is fixedly connected (in this embodiment, it is fixedly connected by a key) on the shift shaft 410 , and the shift knob 580 is fixed on the shift shaft 410 via a screw spring washer 590 .

[0032] like Figure 4 and Figure 6 As shown, the third gear 250 is provided with a plurality of equally spaced first transmission members 252 and a third transmission member 253 at two axial end faces, and the second gear 240 and the fourth gear 260 are provided with a plurality of equally spaced second transmission members 241 and a plurality of equally spaced fourth transmission members 261 at the end faces facing the third gear 250. The sixth gear 340 is provided with a plurality of equally spaced sixth transmission members 342 and an eighth transmission member 343 at two axial end faces, and the fifth gear 330 and the seventh gear 350 are provided with a plurality of equally spaced fifth transmission members 331 and a plurality of equally spaced seventh transmission members 351 at the end faces facing the sixth gear 340.

[0033] The first shift fork 460 and the second shift fork 440 can drive the third gear 250 and the sixth gear 340 to generate corresponding axial displacements as the axial displacements of the first cylindrical cam groove 411 and the second cylindrical cam groove 412 change. When the third gear 250 slides to the point where the first transmission member 252 and the second transmission member 241 are nested and the third transmission member 253 and the fourth transmission member 261 are disengaged, it is the first positive position; when the third gear 250 slides to the point where the first transmission member 252 and the second transmission member 241 are disengaged and the third transmission member 253 and the fourth transmission member 261 are disengaged, it is the first zero position; when the third gear 250 slides to the point where the third transmission member 253 and the fourth transmission member 261 are nested and the first transmission member 252 and the second transmission member 241 are disengaged, it is the first negative position. When the sixth gear 340 slides to the point where the sixth transmission member 342 is nested with the fifth transmission member 331 and the eighth transmission member 343 is disengaged from the seventh transmission member 351, it is the second positive position; when the sixth gear 340 slides to the point where the sixth transmission member 342 is disengaged from the fifth transmission member 331 and the eighth transmission member 343 is disengaged from the seventh transmission member 351, it is the second zero position; when the sixth gear 340 slides to the point where the eighth transmission member 343 is nested with the seventh transmission member 351 and the sixth transmission member 342 is disengaged from the fifth transmission member 331, it is the second negative position.

[0034] like Figure 3 , Figure 4 and Figure 5 As shown, a worm wheel 120 is sleeved between the first gear 230 and the second gear 240 on the driving shaft 210, and the worm wheel 120 is fixedly connected and installed at the second step 212. In this example, a retaining ring groove is provided between the worm wheel 120 and the second gear 240, and a shaft retaining ring 280 is inserted into the retaining ring groove. The shaft retaining ring 280 ensures that the worm wheel 120 will not contact or interfere with the second gear 240, affecting its free rotation relative to the driving shaft 210. In addition to this embodiment, it can also be a step limit to prevent the two from interfering. The worm wheel 120 is meshed with the input worm 110. The output component (in this embodiment, the output gear 610) is fixedly installed on the driven shaft 310 through a nut 620 and a flat washer 630 key connection. The output gear 610 is set at the tenth step 315 facing the driven shaft 310 and beyond the box cover 530. When power is input from the input worm 110, the worm wheel 120 and the driving shaft 210 are driven to rotate around the axis as a whole.

[0035] When the shift knob 580 is rotated to the first gear position, the steel ball of the spring plunger 560 abuts against the positioning hole 571 provided on the positioning plate 570 to position the shift shaft 410. The rotation of the shift shaft 410 drives the first cylindrical cam groove 411 and the second cylindrical cam groove 412 on the shift shaft 410 to rotate synchronously. The first shift fork 460 and the second shift fork 440 change with the axial displacement of the first cylindrical cam groove 411 and the second cylindrical cam groove 412, thereby driving the third gear 250 and the sixth gear 340 to generate corresponding axial displacement. At this time, it is the first speed change output mode. In the first speed change output mode, the first gear 230 rotates at the same speed as the driving shaft 210, and the first gear 230 drives the fifth gear 330 to rotate. At this time, the sixth gear 340 is located in the second positive position, and the third gear 250 is located in the first zero position. The fifth gear 330 drives the sixth gear 340 to rotate at the same speed, and the driven shaft 310 rotates at the same speed as the sixth gear 340 through a key connection. The driven shaft 310 outputs power through the output gear 610 on the output end at the speed after the speed change.

[0036] When the shift knob 580 is rotated to the second gear position, the positioning hole 571 of the positioning plate 570 is disengaged from the spring plunger 560 and then realigned, and the steel ball is again inserted into the next positioning hole 571 for positioning, and the shift shaft 410 rotates to drive the first cylindrical cam groove 411 and the second cylindrical cam groove 412 on the shift shaft 410 to rotate, and the first shift fork 460 and the second shift fork 440 change with the axial displacement of the first cylindrical cam groove 411 and the second cylindrical cam groove 412, thereby driving the third gear 250 and the sixth gear 340 to produce corresponding axial displacement. At this time, it is the second speed output mode. In the second speed change output mode, the third gear 250 is located in the first positive position, the sixth gear 340 is located in the second zero position, the driving shaft 210 drives the third gear 250 to rotate, the third gear 250 drives the second gear 240 to rotate at the same speed, the second gear 240 drives the sixth gear 340 to rotate, the driven shaft 310 is connected with the sixth gear 340 through a key and rotates at the same speed, and the driven shaft 310 outputs power through the output gear 610 on the output end according to the speed after the speed change.

[0037] When the shift knob 580 is rotated to the third gear, the positioning hole 571 of the positioning plate 570 is disengaged from the spring plunger 560 and then realigned, and the steel ball is again inserted into the next positioning hole 571 for positioning, and the shift shaft 410 rotates to drive the first cylindrical cam groove 411 and the second cylindrical cam groove 412 on the shift shaft 410 to rotate, and the first shift fork 460 and the second shift fork 440 change with the axial displacement of the first cylindrical cam groove 411 and the second cylindrical cam groove 412, thereby driving the third gear 250 and the sixth gear 340 to produce corresponding axial displacement. At this time, it is the third speed output mode. In the third speed change output mode, the sixth gear 340 is located at the second negative position, the third gear 250 is located at the first zero position, the driving shaft 210 drives the third gear 250 to rotate, the third gear 250 drives the seventh gear 350 to rotate, the seventh gear 350 drives the sixth gear 340 to rotate at the same speed, the driven shaft 310 is connected with the sixth gear 340 through a key and rotates at the same speed as a whole, and the driven shaft 310 outputs power through the output gear 610 on the output end according to the speed after the speed change.

[0038] When the shift knob 580 is rotated to the fourth gear, the positioning hole 571 of the positioning plate 570 is disengaged from the spring plunger 560 and then realigned, and the steel ball is again inserted into the next positioning hole 571 for positioning. The shift shaft 410 rotates to drive the first cylindrical cam groove 411 and the second cylindrical cam groove 412 on the shift shaft 410 to rotate, and the first shift fork 460 and the second shift fork 440 change with the axial displacement of the first cylindrical cam groove 411 and the second cylindrical cam groove 412, thereby driving the third gear 250 and the sixth gear 340 to produce corresponding axial displacement. At this time, it is the fourth speed output mode. In the fourth speed change output mode, the third gear 250 is located at the first negative position, the sixth gear 340 is located at the second zero position, the driving shaft 210 drives the third gear 250 to rotate, the third gear 250 drives the fourth gear 260 to rotate at the same speed, the fourth gear 260 drives the eighth gear 360 to rotate, the eighth gear 360 is fixed on the driven shaft 310 so that the two rotate at the same speed as a whole, and the driven shaft 310 outputs power through the output gear 610 on the output end according to the speed after the speed change.

[0039] With the change of the rotation angle of the shift shaft 410, the first shift fork 460 drives the third gear 250 to have three states: the first positive position, the first zero position, and the first negative position; the second shift fork 440 drives the sixth gear 340 to have three states: the second positive position, the second zero position, and the second negative position. The first cylindrical cam groove 411 and the second cylindrical cam groove 412 on the shift shaft 410 are in a logical relationship in terms of axial displacement change. When the first shift fork 460 drives the third gear 250 to the first positive position or the first negative position, the second shift fork 440 limits the sixth gear 340 to the second zero position; when the second shift fork 440 drives the sixth gear 340 to the second positive position or the second negative position, the first shift fork 460 limits the third gear 250 to the first zero position, so that the first shift fork 460 and the second shift fork 440 have an interlocking function with each other. The gear combination sequence of the first gear, the second gear, the third gear and the fourth gear in this example is the application of this embodiment, but the gear combination sequence of the shifting gears of this application is not limited to the combination sequence of this embodiment, and the gear combination sequence different from this embodiment obtained by adjusting the logical relationship between the first cylindrical cam groove 411 and the second cylindrical cam groove 412 also belongs to the scope of this application. The gear ratios of the four pairs of gears, namely, the first gear 230 and the fifth gear 330, the second gear 240 and the sixth gear 340, the third gear 250 and the seventh gear 350, and the fourth gear 260 and the eighth gear 360, are not equal to each other.

[0040] like Figure 4 As shown, the two ends of the driving shaft 210 are provided with the first bearing 220 and the second bearing 270, the two ends of the driven shaft 310 are provided with the third bearing 320 and the fourth bearing 370, and the two ends of the shift shaft 410 are provided with the fifth bearing 420 and the sixth bearing 470. The first bearing 220, the third bearing 320 and the fifth bearing 420 are fixed to the bearing holes 513, 512, 511 on the housing 510. The second bearing 270, the fourth bearing 370 and the sixth bearing 470 are fixed to the case cover 530. The driven shaft 310 and the shift shaft 410 have a section of the shaft body extending beyond the supporting bearing at the end of the case cover 530, and the first seal 380 and the second seal 480 are respectively provided thereon. The outer rings of the first seal 380 and the second seal 480 cooperate with the case cover 530 and the end faces are flush with the case cover surface, which play a sealing role.

[0041] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A combined gearbox, comprising an input module, a speed change module, an output module and a housing, wherein the speed change module is installed in the housing, characterized in that: The input module includes an input worm and a worm wheel, and the input worm and the worm wheel are meshed. The speed change module includes a driving shaft, a driven shaft and a shifting mechanism. The output module is fixedly arranged on the driven shaft, and the worm wheel is fixedly arranged on the driving shaft. The driving shaft is parallel to the driven shaft. The driving shaft is sequentially sleeved with a first gear fixed relative to the driving shaft, a second gear that can only rotate relative to the driving shaft, a third gear that can only slide along the axial direction relative to the driving shaft, and a fourth gear that can only rotate relative to the driving shaft. The driven shaft is sequentially sleeved with a fifth gear that can only rotate relative to the driven shaft, a sixth gear that can only slide along the axial direction relative to the driven shaft, a seventh gear that can only rotate relative to the driven shaft, and an eighth gear that is fixed relative to the driven shaft. The first gear and the fifth gear are sleeved in sequence along the axial direction. The first gear, the second gear and the sixth gear, the third gear and the seventh gear, the fourth gear and the eighth gear, each group of two gears are meshed with each other and the gear ratio is unequal; the third gear is provided with a first annular groove, the sixth gear is provided with a second annular groove, and the shift mechanism is engaged with the first annular groove and the second annular groove; the first transmission member and the second transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the third gear and the second gear, the third transmission member and the fourth transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the third gear and the fourth gear, the sixth transmission member and the fifth transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the sixth gear and the fifth gear, and the eighth transmission member and the seventh transmission member that can be nested with each other are respectively arranged on the opposite end surfaces of the sixth gear and the seventh gear; The shift mechanism comprises a shift shaft, a first shift fork, a second shift fork and a driven member, the shift shaft is parallel to the driven shaft, the first shift fork and the second shift fork are sleeved on the shift shaft, the first shift fork is engaged with the first annular groove, the second shift fork is engaged with the second annular groove, the shift shaft is sequentially provided with a first cylindrical cam groove and a second cylindrical cam groove along the axial direction, the first shift fork and the second shift fork are both provided with driven holes on radial surfaces, and the two driven members respectively pass through the driven holes on the first shift fork and the second shift fork and are engaged in the first cylindrical cam groove and the second cylindrical cam groove; The first transmission member and the second transmission member, the third transmission member and the fourth transmission member, the sixth transmission member and the fifth transmission member, the eighth transmission member and the seventh transmission member, which can be nested with each other, are several equally divided concave and convex structures between each other's end faces. They are nested with each other and have virtual intervals. When nested with each other, they can limit their rotation with each other.

2. The combined gearbox according to claim 1, characterized in that: The shift mechanism also includes a clamping member. The first shift fork and the second shift fork are both provided with clamping grooves at axial positions corresponding to the driven hole. The clamping member is clamped to the clamping groove and covers the driven hole.

3. The combined gearbox according to claim 1, characterized in that: The first cylindrical cam groove has an axial displacement position of a first positive position, a first zero position and a first negative position relative to the shift shaft, and the second cylindrical cam groove has an axial displacement position of a second positive position, a second zero position and a second negative position relative to the shift shaft. The axial displacement positions of the first cylindrical cam groove and the second cylindrical cam groove can form a logical self-locking relationship with each other.

4. The combined gearbox according to any one of claims 1 to 3, characterized in that: The end of the shift shaft is fixedly provided with a positioning plate and a shift knob in sequence along the axial direction. A support hole is provided on the end face of the housing close to the end of the shift shaft, a spring plunger is provided in the support hole, and a positioning hole is provided on the end face of the positioning plate facing the housing, and the spring plunger can be inserted into the positioning hole.

5. The combined gearbox according to any one of claims 1 to 3, characterized in that: The third gear is key-connected to the driving shaft, and the third gear can slide axially relative to the driving shaft but cannot rotate relative to the driving shaft. The sixth gear is key-connected to the driven shaft, and the sixth gear can slide axially relative to the driven shaft but cannot rotate relative to the driven shaft.

6. The combined gearbox according to any one of claims 1 to 3, characterized in that: The output module comprises an output component, an end portion of the driven shaft protrudes out of the box cover toward the box cover, and the output component is mounted on the end portion protruding out of the box cover.

7. The combined gearbox according to any one of claims 1 to 3, characterized in that: The box body comprises a shell, a box cover and positioning screws. The shell and the box cover are provided with positioning pin holes, and positioning screws with positioning pin rods are inserted into the positioning pin holes for positioning and fastening.

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