TWI746600B - Gear device - Google Patents

Abstract

This application discloses a gear device connected to a motor. The motor has a motor housing and a motor shaft protruding from the motor housing and rotating around a specific rotation axis. The gear device includes: a connecting wall having a first through hole formed along the rotating shaft and abutting on the motor housing; an input shaft which is in the first through hole and extending from the rotating shaft The set direction is fitted to the above-mentioned motor shaft; and the gear structure is connected to the above-mentioned input shaft.

Description

Gear device

The present invention relates to a gear device connected to a motor.

In most cases, the gear device is used to transmit the driving force generated by the motor. Therefore, the gear device is often directly connected to the motor (refer to Japanese Patent Laid-Open No. 2003-278848). The gear device disclosed in Japanese Patent Laid-Open No. 2003-278848 has an input gear into which a motor shaft is embedded. The gear device receives the driving force generated by the motor through the input gear, and amplifies the driving force with a specific reduction ratio. Finally, the gear device can output the amplified driving force. According to the technology of Japanese Patent Laid-Open No. 2003-278848, the input gear may not be directly formed on the motor shaft. Therefore, the input gear selected to obtain an appropriate reduction ratio can be installed on the motor shaft. On the other hand, the input gear train and the motor shaft are arranged in series, so the connection system of the gear device and the motor is extended in the extending direction of the rotating shaft of the motor shaft. The designer who designs the input gear can also set the mating length of the input gear and the motor shaft to be smaller. In this case, the length dimension of the extension direction of the rotating shaft is reduced. However, a smaller mating length will eventually lead to a reduction in the torque that can be transmitted from the motor shaft to the input gear.

The purpose of the present invention is to provide a technology that has a smaller size in the extending direction of the rotating shaft of the motor shaft and can transmit a larger torque from the motor to the gear device. A gear device of one aspect of the present invention is connected to a motor. The motor has a motor housing and a motor shaft protruding from the motor housing and rotating around a specific rotation axis. The gear device includes: a connecting wall having a first through hole formed along the rotating shaft and abutting on the motor housing; an input shaft which is in the first through hole and extending from the rotating shaft The set direction is fitted to the above-mentioned motor shaft; and the gear structure is connected to the above-mentioned input shaft.

<First Embodiment> If the torque output from the motor is large, a strong member must be used for the connection with the motor housing. Therefore, a thicker plate-shaped member is often used for the part connected with the motor housing. The inventor of the present invention proposes the following proposal, that is, the input shaft of the gear device is connected to the shaft of the motor in a through hole formed in a thicker plate-shaped member, so as to obtain a smaller size of the connecting structure of the gear device and the motor . In the first embodiment, an exemplary gear device will be described. FIG. 1 is a schematic cross-sectional view of the gear device 100 of the first embodiment. 1, the gear device 100 will be described. The gear device 100 is connected to the motor MTR. The motor MTR can also be a common and/or commercially available motor device. The principle of this embodiment is not limited by the specific type of motor MTR. The motor MTR includes a motor housing MHG and a motor shaft MST. Various parts (for example, coils or stator cores) for generating driving force are contained in the motor housing MHG. The motor shaft MST rotates around the rotation axis RAX. The motor shaft MST protrudes from the motor housing MHG along the rotation axis RAX. The motor shaft MST is connected to the gear device 100. The gear device 100 includes a connecting member 200, an input shaft 300 and a gear structure 400. The connecting member 200 is arranged between the motor MTR and the gear structure 400. The connecting member 200 is connected to the motor MTR and the gear structure 400. The input shaft 300 is arranged in a space surrounded by the connecting member 200, the gear structure 400, and the motor MTR. The input shaft 300 is connected to the motor shaft MST. The input shaft 300 rotates around the rotation axis RAX together with the motor shaft MST. The input shaft 300 meshes with the gear structure 400. Therefore, the rotation of the motor shaft MST and the input shaft 300 is transmitted to the gear structure 400. The connecting member 200 includes a connecting wall 210 and a peripheral wall 220. The connecting wall 210 is used for connecting with the motor MTR. The connecting wall 210 is a plate-shaped member having substantially the same shape as the end surface of the motor housing MHG, and overlaps the end surface. The motor shaft MST protrudes from this end surface. The connecting wall 210 may also be substantially circular or substantially rectangular. The principle of this embodiment is not limited by the specific shape of the connecting wall 210. The peripheral wall 220 is a cylindrical member extending from the peripheral surface of the connecting wall 210 toward the side opposite to the motor MTR. The peripheral wall 220 is used for connection with the gear structure 400. The connecting wall 210 is thicker than the peripheral wall 220. Therefore, a larger torque is appropriately transmitted from the motor MTR to the gear device 100. The connecting wall 210 includes a first surface 211, a second surface 212, an outer peripheral surface 213, and an inner peripheral surface 214. The first surface 211 abuts against the motor housing MHG. The second surface 212 opposite to the first surface 211 faces the gear structure 400. The first surface 211 and the second surface 212 are formed as flat surfaces, but they are not limited to this. The thickness dimension of the connecting wall 210 determined between the first surface 211 and the second surface 212 is determined in a manner suitable for the torque output from the motor MTR. If the torque output from the motor MTR is larger, the thickness dimension of the connecting wall 210 is set to a larger value. If the torque output from the motor MTR is small, the thickness dimension of the connecting wall 210 can also be set to a small value. A first through hole 215 is formed in the connecting wall 210. The first through hole 215 extends along the rotation axis RAX between the first surface 211 and the second surface 212. The inner peripheral surface 214 forms the inner peripheral surface of the first through hole 215. The rotation axis RAX may be the central axis of the first through hole 215. The motor shaft MST protrudes into the first through hole 215 along the rotation axis RAX. The protruding amount of the motor shaft MST from the motor housing MHG is smaller than the length of the first through hole 215 in the extending direction of the rotating shaft RAX (or the thickness of the connecting wall 210). The input shaft 300 is fitted to the motor shaft MST in the first through hole 215. The input shaft 300 and the motor shaft MST are neatly arranged along the rotation axis RAX. The thickness interval between the first surface 211 and the second surface 212 is used not only for the connection of the connecting member 200 to the motor housing MHG, but also for the connection of the input shaft 300 to the motor shaft MST. Therefore, the extension direction of the rotating shaft RAX The length dimension of the connecting structure of the gear device 100 and the motor MTR is not larger than necessary. <Second Embodiment> The designer who designs the gear device can also design various connecting structures for connecting the input shaft to the motor shaft. For example, the designer can also provide a fitting structure in which the motor shaft is embedded or externally embedded in the input shaft. In the second embodiment, an exemplary fitting structure for connecting the input shaft to the motor shaft is described. FIG. 2 is a schematic cross-sectional view of the input shaft 300. 1 and 2, the input shaft 300 will be described. As shown in FIG. 1, the motor shaft MST includes a first end surface FES facing the gear structure 400. As shown in FIG. 2, the first end surface FES is provided with a tapered recess TPR that narrows toward the motor housing MHG (refer to FIG. 1). The tapered recess TPR is formed on the motor shaft MST so as to extend along the rotation axis RAX. The input shaft 300 is partially inserted into the tapered recess TPR. The bottom part of the tapered recess TPR may also have a larger size in the radial direction than other parts of the tapered recess TPR. As a result, the tapered recess TPR easily penetrates the motor shaft MST. The motor shaft MST includes a bottom surface BTS and an inner peripheral surface ICS. The bottom surface BTS forms the bottom of the tapered recess TPR. The inner peripheral surface ICS forms a peripheral surface of a space narrowed from the first end surface FES toward the bottom surface BTS. The input shaft 300 includes a tapered shaft portion 310, an input gear portion 320 and an intermediate portion 330. The intermediate portion 330 is located between the tapered shaft portion 310 and the input gear portion 320. The tapered shaft portion 310, the intermediate portion 330, and the input gear portion 320 are arranged in the extending direction of the rotating shaft RAX. The input gear portion 320 has a larger outer diameter than the tapered shaft portion 310 and the intermediate portion 330. Therefore, the input gear part 320 can be easily machined. In this embodiment, the tapered shaft portion 310 is an example of a fitting portion that is fitted to the motor shaft MST. The tapered shaft portion 310 has a shape complementary to the tapered space formed by the inner peripheral surface ICS. The tapered shaft 310 is inserted into the tapered recess TPR. At this time, the intermediate portion 330 and the input gear portion 320 protrude from the first end surface FES (refer to FIG. 1). As shown in FIG. 2, a second through hole 340 is formed in the input shaft 300. The second through hole 340 extends along the rotation axis RAX. As shown in FIG. 1, the gear device 100 includes a first fixing bolt 301 for fixing the input shaft 300 to the motor shaft MST. The first fixing bolt 301 is inserted into the second through hole 340 (refer to FIG. 2), and is screwed into the screw hole TRH formed in the motor shaft MST so as to open at the bottom surface BTS. As a result, the tapered shaft portion 310 is firmly fitted to the motor shaft MST in the extending direction of the rotating shaft RAX. As shown in FIG. 1, the tapered shaft portion 310 is shorter than the thickness dimension of the connecting wall 210 determined by the first surface 211 and the second surface 212. Therefore, the connection of the input shaft 300 to the motor shaft MST is performed in the first through hole 215. As a result, the connecting structure of the gear device 100 and the motor MTR can have a smaller size in the extending direction of the rotating shaft RAX. As shown in FIG. 1, the gear device 100 includes a second fixing bolt 302. The second fixing bolt 302 is used to fix the motor housing MHG to the connecting wall 210. The connecting wall 210 is formed with a blind hole 216 penetrating from the first surface 211 toward the second surface 212. The blind hole 216 extends substantially parallel to the first through hole 215. A female thread is formed on the inner wall surface of the connecting wall 210 forming the blind hole 216. The second fixing bolt 302 is screwed to the female thread. The tapered shaft portion 310 is shorter than the blind hole 216 in the extending direction of the rotation axis RAX. Therefore, the connection of the input shaft 300 to the motor shaft MST is performed in the first through hole 215. As a result, the connecting structure of the gear device 100 and the motor MTR can have a smaller size in the extending direction of the rotating shaft RAX. <Third Embodiment> In order to prevent liquid from leaking into the boundary between the motor housing and the motor shaft, a seal ring is often used. As described with respect to the second embodiment, if the input shaft is fitted into the motor shaft, the outer diameter of the motor will slightly increase. As a result, the sealing performance of the seal ring may deteriorate. In the third embodiment, an exemplary fitting technique that hardly affects the sealing performance will be described. As shown in FIG. 1, the peripheral wall 220 of the connecting member 200 is a cylindrical body that expands in the radial direction from the outer peripheral surface of the connecting wall 210 and extends toward the gear structure 400. The peripheral wall 220 forms a connecting space 221 for connecting the input gear portion 320 to the gear structure 400. The connecting space 221 communicates with the first through hole 215 of the connecting wall 210. The connecting space 221, the first through hole 215, and the internal space of the gear structure 400 are filled with lubricating fluid. As a result, the wear speed of the input gear portion 320 and the gear structure 400 can be kept at a low level. In this embodiment, the liquid system is exemplified by a lubricating liquid. As shown in Fig. 1, the motor MTR has a seal ring SRG surrounding the motor shaft MST. The seal ring SRG prevents lubricating fluid from penetrating into the boundary between the motor housing MHG and the motor shaft MST. The motor housing MHG includes a contact surface ABS contacting the first surface 211. In the motor housing MHG, a ring-shaped recess adjacent to the motor shaft MST and surrounding the motor shaft MST is formed so as to be recessed from the abutting surface ABS. The seal ring SRG is inserted into the ring-shaped recess. As a result, the lubricating fluid does not easily penetrate into the boundary between the motor housing MHG and the motor shaft MST. The tapered shaft portion 310 includes a second end surface 311 facing the bottom surface BTS of the motor shaft MST. The second end surface 311 is located between the first end surface FES and the contact surface ABS in a state where the tapered shaft portion 310 is fitted into the tapered recess TPR of the motor shaft MST. There is no tapered shaft portion 310 on an imaginary plane orthogonal to the rotation axis RAX so as to traverse the seal ring SRG. Therefore, when the tapered shaft portion 310 is inserted into the motor shaft MST, even if the diameter of the motor shaft MST is enlarged, the motor shaft MST is not enlarged on the above-mentioned imaginary plane, so the sealing performance of the seal ring SRG is hardly affected. Influence. <Fourth Embodiment> The principle of the above-mentioned embodiment can be applied to various gear structures. The gear structure may also have a mechanism including a swing gear having a center that circulates around the rotating shaft of the motor. Instead, the gear structure may also have a mechanism including planetary gears. In the fourth embodiment, an exemplary gear structure having a swing gear will be described. 3 is a schematic cross-sectional view of the gear structure 400 along the line III-III shown in FIG. 1. The gear structure 400 will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the gear structure 400 includes an outer cylinder 410, a carrier 420, a plurality of (3) crankshaft assemblies 500 (one of the three crankshaft assemblies 500 is shown in FIG. 1), and a gear part 600, and 2 main bearings 710, 720. The outer cylinder 410 is connected to the connecting member 200. The input gear part 320 is connected to the crankshaft assembly 500. As described in relation to the first embodiment, the input gear portion 320 rotates around the rotation axis RAX, and transmits driving force to the crankshaft assembly 500. As a result, each of the crankshaft assembly 500 rotates around the transmission axis TAX (one of the three transmission axes TAX is shown in FIG. 1) extending substantially parallel to the rotation axis RAX. The transmission axis TAX is set at approximately equal intervals on an imaginary circle centered on the rotation axis RAX. The rotation of each crankshaft assembly 500 is transmitted to the gear part 600 arranged in the internal space surrounded by the outer cylinder 410 and the carrier 420. As shown in FIG. 1, a plurality of (2) main bearings 710 and 720 are inserted into the annular space formed between the outer cylinder 410 and the carrier 420 surrounded by the outer cylinder 410. Each of the main bearings 710 and 720 can make the carrier 420 rotate in the outer cylinder 410. The common central axis of the main bearings 710 and 720 may also coincide with the rotation axis RAX of the input gear part 320. The carrier 420 rotates around the rotation axis RAX by the driving force transmitted to the gear part 600. The outer cylinder 410 is fixed to a target member (not shown) to which the gear device 100 is mounted. As shown in FIG. 3, the outer cylinder 410 includes a substantially cylindrical box body 411 and a plurality of internally toothed needles 412. The box body 411 cooperates with the carrier 420 to form a cylindrical inner space for accommodating the crankshaft assembly 500 and the gear part 600. A plurality of internally toothed needles 412 are arranged in a ring shape along the inner peripheral surface of the box body 411 to form an internally toothed ring. Each of the plurality of internally toothed needles 412 is a substantially cylindrical member extending in the extending direction of the rotation axis RAX. Each of the plurality of inner tooth needles 412 is inserted into the groove formed on the inner peripheral surface of the box body 411. Therefore, each of the plurality of internal tooth needles 412 is appropriately held by the box body 411. As shown in FIG. 1, the plurality of internally toothed needles 412 are arranged in a ring shape around the rotation axis RAX at substantially constant intervals. The half-peripheral surface of each of the plurality of internally toothed needles 412 protrudes from the inner peripheral surface of the box body 411 toward the rotation axis RAX. Therefore, the plurality of internal tooth needles 412 function as a plurality of internal teeth meshed with the gear part 600. As shown in FIG. 1, the carrier 420 includes a base 430 and an end plate 440. The carrier 420 is cylindrical as a whole. The end plate 440 has a substantially circular plate shape. The outer peripheral surface of the end plate 440 is partially surrounded by the outer tube 410. The main bearing 710 is fitted into an annular gap formed between the outer circumferential surface of the end plate 440 and the inner circumferential surface of the outer cylinder 410. The base portion 430 includes a substantially disc-shaped substrate portion 431 (refer to FIG. 1) and a plurality of (3) shaft portions 432 (refer to FIG. 3). The outer peripheral surface of the base portion 431 is partially surrounded by the outer tube 410. The main bearing 720 is fitted into an annular gap formed between the outer peripheral surface of the base plate portion 431 and the inner peripheral surface of the outer cylinder 410. The base portion 431 is away from the end plate 440 in the extending direction of the rotation axis RAX. The substrate portion 431 is substantially coaxial with the end plate 440. That is, the rotation axis RAX corresponds to the center axis of the base plate 431 and the end plate 440. The substrate portion 431 includes an inner surface 433 and an outer surface 434 opposite to the inner surface 433. The inner surface 433 opposes the gear part 600. The inner surface 433 and the outer surface 434 are along an imaginary plane (not shown) orthogonal to the rotation axis RAX. A central through hole 435 (refer to FIG. 1) and a plurality of (three) holding through holes 436 (one of the three holding through holes 436 is shown in FIG. 1) are formed in the substrate portion 431. The central through hole 435 extends between the inner surface 433 and the outer surface 434 along the rotation axis RAX. The rotation axis RAX corresponds to the central axis of the central through hole 435. Keep the center axis of the through hole 436 consistent with the transmission axis TAX. The holding through hole 436 extends between the inner surface 433 and the outer surface 434 along the corresponding transmission axis TAX. A part of the crankshaft assembly 500 is arranged in the holding through hole 436. The end plate 440 includes an inner surface 443 and an outer surface 444 opposite to the inner surface 443. The inner surface 443 opposes the gear part 600. The inner surface 443 and the outer surface 444 are along an imaginary plane (not shown) orthogonal to the rotation axis RAX. A central through hole 445 (refer to FIG. 1) and a plurality of (three) holding through holes 446 (one of the three holding through holes 446 is shown in FIG. 1) are formed in the end plate 440. The central through hole 445 extends between the inner surface 443 and the outer surface 444 along the rotation axis RAX. The rotation axis RAX corresponds to the central axis of the central through hole 445. The holding through holes 446 respectively extend along the corresponding transmission axis TAX between the inner surface 443 and the outer surface 444. The transmission axis TAX corresponds to the central axis of the holding through hole 446, respectively. A part of the crankshaft assembly 500 is arranged in the holding through hole 446. The holding through hole 446 formed in the end plate 440 and the holding through hole 436 formed in the substrate portion 431 are respectively substantially coaxial. Each of the shaft portions 432 extends from the inner surface 433 of the base portion 431 toward the inner surface 443 of the end plate 440. The end plate 440 is connected to each front end surface of the shaft portion 432. The end plate 440 can also be connected to the respective front end surfaces of the shaft 432 by using a reamer bolt, a positioning pin, or other suitable fixing techniques. The principle of this embodiment is not limited by the specific connection technology between each of the end plate 440 and the shaft portion 432. As shown in FIG. 1, the gear portion 600 is disposed between the inner surface 433 of the base plate portion 431 and the inner surface 443 of the end plate 440. The shaft portion 432 penetrates the gear portion 600 and is connected to the end plate 440. As shown in FIG. 1, the gear part 600 includes swing gears 610 and 620. The swing gear 610 is disposed between the end plate 440 and the swing gear 620. The swing gear 620 is disposed between the base portion 431 and the swing gear 610. The swing gears 610 and 620 may also be trochoid gears or cycloid gears formed based on a common design pattern. It is not limited to the configuration having two swing gears 610 and 620 as shown in FIG. 1. Instead, it may have one swing gear or three or more swing gears. Each of the swing gears 610 and 620 includes a plurality of external teeth 630 protruding toward the inner wall of the box body 411 (refer to FIG. 3). When the crankshaft assembly 500 rotates around the transmission axis TAX, the swing gears 610 and 620 engage the plurality of external teeth 630 with the plurality of internal gear needles 412 and move circularly in the box body 411 (ie, swing and rotate). During this period, the centers of the swing gears 610 and 620 will circulate around the rotation axis RAX. The rotation of the outer cylinder 410 or the carrier 420 is caused by the oscillating rotation of the oscillating gears 610 and 620. The central through hole 611 is formed in the center of the swing gear 610. The central through hole 621 is formed in the center of the swing gear 620. The central through hole 611 communicates with the central through hole 445 of the end plate 440 and the central through hole 621 of the swing gear 620. The central through hole 621 communicates with the central through hole 435 of the base plate portion 431 and the central through hole 611 of the swing gear 610. As shown in FIG. 3, a plurality of (3) circular through holes 612 are formed in the swing gear 610. Similarly, a plurality of (3) circular through holes are formed in the swing gear 620. The circular through hole 612 of the swing gear 610 and the circular through hole of the swing gear 620 cooperate with the holding through holes 436 and 446 of the base plate 431 and the end plate 440 to form a receiving space for accommodating the crankshaft assembly 500. A plurality of (3) trapezoidal through-holes 613 (refer to FIG. 3) are formed in the swing gear 610. A plurality of (3) trapezoidal through holes 623 (one of the three trapezoidal through holes 623 is shown in FIG. 1) is formed in the swing gear 620. The shaft 432 of the carrier 420 penetrates through the trapezoidal through holes 613 and 623. The size of the trapezoidal through holes 613 and 623 is determined so as not to interfere with the shaft portion 432. Each of the plural (3) crankshaft assemblies 500 includes a transmission gear 510, a crankshaft 520, journal bearings 531, 532, and crank bearings 541, 542. The crankshaft 520 includes a first journal 521, a second journal 522, a first eccentric portion 523 and a second eccentric portion 524. The first journal 521 is inserted into the holding through hole 446 of the end plate 440. The second journal 522 is inserted into the holding through hole 436 of the substrate portion 431. The journal bearing 531 is inserted into the annular space between the first journal 521 and the inner wall of the end plate 440 forming the holding through hole 446. As a result, the first journal 521 is connected to the end plate 440. The journal bearing 532 is fitted into the annular space between the second journal 522 and the inner wall of the base plate portion 431 where the holding through hole 436 is formed. As a result, the second journal 522 is connected to the substrate portion 431. Therefore, the carrier 420 can appropriately support the three crankshaft assemblies 500. As shown in FIG. 1, the transmission gear 510 is attached to the first journal 521. The first eccentric portion 523 is located between the first journal 521 and the second eccentric portion 524. The second eccentric portion 524 is located between the second journal 522 and the first eccentric portion 523. The crank bearing 541 is fitted into the annular space between the first eccentric portion 523 and the inner wall of the swing gear 610 forming the circular through hole 612. As a result, the swing gear 610 is attached to the first eccentric portion 523. The crank bearing 542 is fitted into the annular space between the second eccentric portion 524 and the inner wall of the swing gear 620 forming a circular through hole. As a result, the swing gear 620 is attached to the second eccentric portion 524. The first journal 521 is coaxial with the second journal 522 and rotates around the transmission axis TAX. Each of the first eccentric portion 523 and the second eccentric portion 524 is formed in a cylindrical shape and is eccentric from the transmission axis TAX. Each of the first eccentric portion 523 and the second eccentric portion 524 rotates eccentrically with respect to the transmission axis TAX, and gives the swing gears 610 and 620 swing rotation. The oscillating rotation of the oscillating gears 610 and 620 is converted into the rotating motion of the outer cylinder 410 around the rotation axis RAX. The intermediate portion 330 and the input gear portion 320 extend from the tapered shaft portion 310 along the rotation axis RAX. The input gear part 320 meshes with the transmission gear 510. As a result, the input gear portion 320 receives a reaction force from the gear structure 400. As shown in FIG. 2, the gear device 100 includes a key 303. The key 303 is inserted into the groove portion recessed on the peripheral surface of the tapered shaft portion 310. A key groove corresponding to the key 303 is formed on the inner peripheral surface ICS of the motor shaft MST. The key 303 is inserted into the key groove formed in the motor shaft MST. As a result, it is difficult to generate relative rotation of the input shaft 300 with respect to the motor shaft MST. <Fifth Embodiment> According to the design principle of the third embodiment, the end of the tapered shaft ends in front of the seal ring. As a result, the performance of the seal ring is unlikely to deteriorate. If the sealing performance of the sealing ring is sufficiently high, or the rigidity of the motor shaft is sufficiently high without deterioration of the sealing performance, the tapered shaft can also be inserted into the motor shaft beyond the sealing ring. In this case, a larger contact area is obtained between the inner peripheral surface of the tapered concave portion of the motor shaft and the outer peripheral surface of the tapered shaft portion. As a result, it is difficult to generate relative rotation between the motor shaft and the tapered shaft when the tapered shaft is mounted to the motor shaft and/or when the driving force is transmitted from the motor to the gear device. In the fifth embodiment, an exemplary fitting technique for suppressing the relative rotation between the motor shaft and the tapered shaft portion will be described. Fig. 4 is a schematic cross-sectional view of the input shaft 300A of the fifth embodiment. With reference to Figs. 1, 2 and 4, the input shaft 300A will be described. The description of the above-mentioned embodiment is used for the elements marked with the same symbols as those of the above-mentioned embodiment. The input shaft 300A can be used instead of the input shaft 300 described with reference to FIG. 2. As in the second embodiment, the input shaft 300A includes an input gear portion 320 and an intermediate portion 330. The description of the second embodiment is cited for these elements. The input shaft 300A further includes a tapered shaft portion 310A. The tapered shaft portion 310A is longer than the tapered shaft portion 310 described with reference to FIG. 2. Fig. 4 shows the motor shaft MSU connected to the input shaft 300A. As in the second embodiment, the motor shaft MSU includes the first end surface FES. The description of the second embodiment is cited for the first end face FES. On the first end surface FES, a tapered recess TPS into which the tapered shaft 310A is inserted is recessed. The tapered recess TPS is deeper than the tapered recess TPR described with reference to FIG. 2. Fig. 4 shows the position of the seal ring SRG described with reference to Fig. 1 by means of a chain line. The length dimension of the tapered shaft portion 310A and the depth dimension of the tapered recess TPS are larger than those of the second embodiment. The tapered shaft portion 310A may be inserted into the tapered recess TPS beyond the chain line indicating the arrangement position of the seal ring SRG. Therefore, the insertion length of the tapered shaft portion 310A into the motor shaft MSU is larger than that of the second embodiment. The contact area between the tapered shaft portion 310A and the motor shaft MSU is proportional to the insertion length of the tapered shaft portion 310A into the motor shaft MSU. Therefore, the contact area between the tapered shaft portion 310A and the motor shaft MSU is larger than in the second embodiment. Since the contact area between the tapered shaft portion 310A and the motor shaft MSU increases, it is difficult for the input shaft 300A to rotate relative to the motor shaft MSU while the first fixing bolt 301 (refer to FIG. 1) is rotated about the rotation axis RAX . This situation means that the operator can easily assemble the input shaft 300A to the motor shaft MSU. Similarly, during the period when the driving force is transmitted from the motor shaft MSU to the input shaft 310A, the input shaft 300A is also difficult to rotate relative to the motor shaft MSU. In this case, a good transmission of driving force from the motor shaft MSU to the input shaft 300A will eventually be realized. The design principles explained in relation to the various embodiments described above can be applied to various gear devices. One of the various features described in relation to one of the various embodiments described above can also be applied to the gear device described in relation to another embodiment. The principle of the above embodiment can also be applied to a gear device that has a crankshaft assembly 500 and an intermediate crank type swing gear in which the crankshaft 520 is arranged on the rotating shaft RAX. In this case, the transmission gear 510 is omitted, and the input shaft may be directly connected to the crankshaft. Here, the above-mentioned embodiment is summarized. (1) The gear device of this embodiment is connected to a motor having a motor housing and a motor shaft protruding from the motor housing and rotating around a specific rotation axis. The gear device includes: a connecting wall having a first through hole formed along the rotating shaft and abutting on the motor housing; an input shaft which is in the first through hole and extending from the rotating shaft The set direction is fitted to the above-mentioned motor shaft; and the gear structure is connected to the above-mentioned input shaft. According to the above configuration, since the connecting wall is in contact with the motor housing, it is directly connected to the motor housing. Since the first through hole is formed in the connecting wall along the rotating shaft, the first through hole overlaps with the connecting wall for connecting to the motor housing. Since the input shaft is connected to the motor shaft in the first through hole, the designer who designs the gear device may not add space in the extending direction of the rotating shaft to connect the input shaft to the motor shaft. Therefore, the connecting structure of the motor and the gear device can have a smaller size in the extending direction of the rotating shaft of the motor shaft. If the torque output by the motor is larger, the thickness of the connecting wall must be set to a larger value. As a result, the first through hole also becomes longer in the extending direction of the rotating shaft. Since the designer can assign a larger value to the fitting length for fitting the input shaft to the motor shaft in the extending direction of the rotating shaft, a larger torque can be transmitted from the motor shaft to the input shaft. (2) In relation to the above configuration, the input shaft may have a fitting portion that is fitted to the motor shaft in the extending direction of the rotation shaft. The fitting portion may be shorter than the thickness dimension of the connecting wall in the extending direction. According to the above configuration, since the extending direction of the fitting portion on the rotating shaft is shorter than the thickness dimension of the connecting wall, the designer does not need to add space in the extending direction of the rotating shaft. Therefore, the connecting structure of the motor and the gear device can have a smaller size in the extending direction of the rotating shaft of the motor shaft. (3) In connection with the above configuration, the gear device may further include a first fixing bolt that fixes the input shaft to the motor shaft. The above-mentioned fitting part may be a tapered shaft part. The motor shaft may also include: a first end surface that is complementary to the tapered shaft portion and is provided with a tapered recess into which the tapered shaft portion is inserted; and a bottom surface that is formed with a screw hole and forms the bottom of the tapered recess . The said tapered recessed part may become narrower toward the said bottom surface from the said 1st end surface. The first fixing bolt may be inserted into a second through hole formed on the input shaft along the rotation shaft, and may be screwed into the screw hole. According to the above configuration, since the tapered shaft portion is inserted into the tapered recessed portion narrowing from the end surface of the motor shaft toward the motor housing, the operator who connects the motor to the gear device can easily mount the input shaft to the motor shaft. Since the first fixing bolt is inserted into the second through hole formed on the input shaft along the rotating shaft and is screwed into the screw hole formed on the bottom surface, the operator can then appropriately fix the input shaft to the motor shaft. If necessary, the operator can remove the first fixing bolt to easily separate the input shaft from the motor shaft. (4) In relation to the above configuration, the input shaft may include an input gear portion extending from the tapered shaft portion along the rotation shaft. The gear structure may also include a transmission gear that meshes with the input gear portion and rotates around a transmission shaft parallel to the rotation shaft. The tapered shaft portion may also have a smaller outer diameter than the input gear portion. According to the above configuration, since the gear structure includes the transmission gear that meshes with the input gear portion and rotates around the transmission shaft parallel to the rotation shaft, the rotation of the motor shaft is appropriately transmitted to the gear structure via the input gear portion. Since the outer diameter of the tapered shaft portion is smaller than that of the input gear portion, the input gear portion is easily formed without interference between the tapered shaft portion and the tool forming the input gear portion. (5) In relation to the above configuration, the connecting wall may include a first surface contacting the motor housing and a second surface opposite to the first surface. The motor may also include a sealing ring surrounding the motor shaft to prevent liquid from penetrating into the boundary between the motor shaft and the motor housing. The motor housing may include a contact surface formed with a ring-shaped recess into which the seal ring is inserted and contacting the first surface. The tapered shaft portion may include a second end surface facing the bottom surface. The second end surface may be located between the first end surface and the contact surface. According to the above configuration, the second end surface of the tapered shaft portion facing the bottom surface forming the bottom of the tapered recess is located between the first end surface of the motor shaft and the contact surface where the seal ring is inserted. Therefore, the slight deformation of the motor shaft caused by the connection of the tapered shaft portion to the motor shaft is unlikely to affect the sealing performance of the seal ring. (6) In relation to the above configuration, the length of the tapered shaft inserted into the tapered recess may be smaller than the thickness dimension of the connecting wall. According to the above structure, since the length of the tapered shaft inserted into the tapered recess is smaller than the thickness dimension of the connecting wall, the designer may not add space in the extending direction of the rotating shaft. Therefore, the connecting structure of the motor and the gear device can have a smaller size in the extending direction of the rotating shaft of the motor shaft. (7) In connection with the above configuration, the gear device may further include a second fixing bolt for fixing the motor housing to the connecting wall. The second fixing bolt may be screwed into a blind hole that is punched in the connecting wall and formed with a female thread that engages with the second fixing bolt. The length of the tapered shaft inserted into the tapered recess may be smaller than the length of the blind hole. According to the above configuration, since the length of the tapered shaft inserted into the tapered recess is smaller than the length of the blind hole formed with the female thread that engages with the second fixing bolt, the designer does not need to add space in the extending direction of the rotating shaft. Therefore, the connecting structure of the motor and the gear device can have a smaller size in the extending direction of the rotating shaft of the motor shaft. The above technology has a small size in the extending direction of the rotating shaft of the motor shaft, and can transmit a large torque from the motor to the gear device. [Industrial Applicability] The principles of the above-mentioned embodiment are preferably used in various gear devices.

100‧‧‧Gear device 200‧‧‧Connecting member 210‧‧‧Connecting wall 211‧‧‧First surface 212‧‧‧Second surface 213‧‧‧Outer peripheral surface 214‧‧‧Inner peripheral surface 215‧‧‧Second 1 Through hole 216‧‧‧Blind hole 220‧‧Perimeter wall 221‧‧Connecting space 300‧‧‧Input shaft 300A‧‧‧Input shaft 301‧‧‧First fixing bolt 302‧‧‧Second fixing bolt 303‧ ‧‧Key 310‧‧‧Taper shaft part 310A‧‧‧Taper shaft part 311‧‧‧Second end surface 320‧‧‧Input gear part 330‧‧‧Intermediate part 400‧‧‧Gear structure 410‧‧‧ Outer cylinder 411‧‧‧Box body 412‧‧‧Internal tooth needle 420‧‧‧Carrier 430‧‧‧Base 431‧‧‧Base part 432‧‧‧Shaft part 433‧‧‧Inner surface 434‧‧‧Outer surface 435 ‧‧‧Central through hole 436‧‧‧Retaining through hole 440 Shaft assembly 510‧‧‧Transmission gear 520‧‧‧Crank shaft 521‧‧‧First journal 522‧‧‧Second journal 523‧‧‧First eccentric part 524‧‧‧Second eccentric part 531‧‧ ‧Journal bearing 532‧‧‧Journal bearing 541‧‧‧Crank bearing 542‧‧‧Crank bearing 600‧‧‧Gear part 610‧‧‧Swing gear 611‧‧‧Central through hole 612‧‧‧Circular through hole 613‧‧‧Trapezoidal through hole 620‧‧‧Swing gear 621‧‧‧Central through hole 623‧‧‧ Trapezoidal through hole 630‧‧ External tooth 710‧‧‧Main bearing 720‧‧‧Main bearing ABS‧‧‧Arrival Connection surface BTS‧‧‧Bottom surface FES‧‧‧First end surface ICS‧‧‧Inner peripheral surface MHG‧‧‧Motor housing MST‧‧‧Motor shaft MSU‧‧‧Motor shaft MTR‧‧‧Motor RAX‧‧‧Rotation Shaft SRG‧‧‧Sealing ring TAX‧‧‧Transmission shaft TPR‧‧‧Conical recess TPS‧‧‧Conical recess TRH‧‧‧Screw hole

Fig. 1 is a schematic cross-sectional view of an exemplary gear device. Fig. 2 is a schematic cross-sectional view of the input shaft of the gear device shown in Fig. 1. Fig. 3 is a schematic cross-sectional view of the gear structure of the gear device shown in Fig. 1. Figure 4 is a schematic cross-sectional view of an alternative input shaft.

100‧‧‧Gear device

200‧‧‧Connecting member

210‧‧‧Connecting wall

211‧‧‧Side 1

212‧‧‧Side 2

213‧‧‧Outer peripheral surface

214‧‧‧Inner peripheral surface

215‧‧‧1st through hole

216‧‧‧Blind Hole

220‧‧‧ Zhoubi

221‧‧‧Connecting Space

300‧‧‧Input shaft

301‧‧‧The first fixing bolt

302‧‧‧Second fixing bolt

303‧‧‧ key

310‧‧‧Taper shaft

311‧‧‧Second end face

320‧‧‧Input gear part

330‧‧‧Middle part

400‧‧‧Gear structure

410‧‧‧Outer cylinder

411‧‧‧Box

412‧‧‧Internal tooth needle

420‧‧‧Carrier

430‧‧‧Base

431‧‧‧Substrate Department

432‧‧‧Shaft

433‧‧‧Inner surface

434‧‧‧Outer surface

435‧‧‧Central through hole

436‧‧‧Keep through hole

440‧‧‧end plate

443‧‧‧Inner surface

444‧‧‧Outer surface

445‧‧‧Central through hole

446‧‧‧Keep through hole

500‧‧‧Crank shaft assembly

510‧‧‧Transmitting gear

520‧‧‧Crankshaft

521‧‧‧The first journal

522‧‧‧Second journal

523‧‧‧The first eccentric part

524‧‧‧Second eccentric part

531‧‧‧Journal bearing

532‧‧‧Journal Bearing

541‧‧‧Crank bearing

542‧‧‧Crank bearing

600‧‧‧Gear Department

610‧‧‧Swing gear

611‧‧‧Central through hole

613‧‧‧trapezoidal through hole

620‧‧‧Swing gear

621‧‧‧Central through hole

623‧‧‧ Trapezoidal through hole

710‧‧‧Main bearing

720‧‧‧Main bearing

ABS‧‧‧Abutment surface

BTS‧‧‧Bottom

FES‧‧‧1st end face

MHG‧‧‧Motor housing

MST‧‧‧Motor shaft

MTR‧‧‧Motor

RAX‧‧‧Rotation axis

SRG‧‧‧Seal ring

TAX‧‧‧Transfer axis

TPR‧‧‧Conical recess

TRH‧‧‧Screw hole

Claims (10)

A gear device is connected to a motor. The motor has a motor housing and a motor shaft protruding from the motor housing and rotating around a specific rotation axis; and the gear device includes: a connecting wall along the rotation axis In this way, a first through hole is formed and abuts against the motor housing; the input shaft has a fitting portion that fits into the motor shaft in the first through hole, and a second through hole is formed; a gear A structure that is connected to the input shaft; and a first fixing bolt that fixes the input shaft to the motor shaft; and the gear structure has a crank shaft assembly including an eccentric portion, and rotatably supports the crank shaft The carrier of the assembly; the carrier has a central through hole extending along the rotating shaft; the first fixing bolt is inserted into the input shaft along the rotating shaft in a state where the head is arranged in the central through hole The second through hole is screwed into the screw hole formed in the motor shaft. The gear device of claim 1, wherein the extending direction of the fitting portion on the rotating shaft is shorter than the thickness dimension of the connecting wall. The gear device of claim 2, wherein the fitting portion is a tapered shaft portion, and the motor shaft includes: a first end surface that is complementary to the tapered shaft portion and is provided with a tapered recess into which the tapered shaft portion is inserted ; And the bottom surface, which is formed with the above-mentioned screw hole and the above-mentioned tapered recess The bottom of the portion; the tapered recessed portion narrows from the first end surface toward the bottom surface. The gear device of claim 3, wherein the input shaft includes an input gear portion extending from the tapered shaft portion along the rotation shaft, and the gear structure includes a transmission that meshes with the input gear portion and is parallel to the rotation shaft For the transmission gear for shaft rotation, the tapered shaft portion has a smaller outer diameter than the input gear portion. For the gear device of claim 3 or 4, wherein the connecting wall includes a first surface abutting on the motor housing and a second surface opposite to the first surface, and the motor includes surrounding the motor shaft to prevent A seal ring in which liquid penetrates into the boundary between the motor shaft and the motor housing, the motor housing includes an abutting surface formed with a ring-shaped recess into which the seal ring is inserted and abutting against the first surface, the The tapered shaft includes a second end surface facing the bottom surface, and the second end surface is located between the first end surface and the contact surface. The gear device of claim 3 or 4, wherein the length of the tapered shaft inserted into the tapered recess is smaller than the thickness dimension of the connecting wall. The gear device of claim 5, wherein the length of the tapered shaft inserted into the tapered recess is smaller than the thickness dimension of the connecting wall. For the gear device of claim 3 or 4, it is further provided with a second fixing bolt for fixing the motor housing to the connecting wall, the second fixing bolt is screwed into a hole in the connecting wall, and is formed with The length of the tapered shaft portion inserted into the tapered recessed portion of the blind hole of the female thread to which the second fixing bolt engages is smaller than the length of the blind hole. According to claim 5, the gear device further includes a second fixing bolt for fixing the motor housing to the connecting wall, and the second fixing bolt is screwed into a hole in the connecting wall and formed with the second fixing bolt. The length of the tapered shaft part inserted into the tapered recess of the blind hole of the female thread to which the fixing bolt engages is less than the length of the blind hole. The gear device of claim 6, further comprising a second fixing bolt for fixing the motor housing to the connecting wall, and the second fixing bolt is screwed into a hole in the connecting wall and formed with the second fixing bolt. The length of the tapered shaft part inserted into the tapered recess of the blind hole of the female thread to which the fixing bolt engages is less than the length of the blind hole.

Images