Gear shifting mechanism and inner speed change hub

Abstract

The utility model belongs to the technical field of internal transmissions, and particularly relates to a gear shifting mechanism and an internal speed change hub. The gear shifting mechanism comprises a gear shifting control piece, a gear shifting pawl and a gear shifting pawl seat, the gear shifting pawl seat is provided with a gear shifting pawl groove and arranged on a mandrel, the gear shifting pawl is installed in the gear shifting pawl groove and has the outward opening state and the inward folding state, the gear shifting control piece is provided with an opening groove, and the gear shifting pawl seat is arranged on the mandrel. The open grooves are used for controlling the gear shifting pawls to be unfolded or folded and used for fixing or moving a sun gear of the transmission mechanism, the open grooves are formed in the control parts, and at least one control part alternately controls the two gear shifting pawls. According to the gear shifting control piece of the gear shifting mechanism, the two control parts can control the three gear shifting pawls, compared with the mode that each control part can only control one gear shifting pawl independently, the length of the gear shifting control piece can be further shortened, and then the width of the whole inner speed change hub is shortened.

Description

Technical Field

[0001] The utility model belongs to the technical field of internal transmissions, and particularly relates to a gear shifting mechanism and an internal transmission hub. Background Art

[0002] Chinese patent document CN219884026U discloses a shifting mechanism and an internal speed hub. The operating mechanism of the shifting mechanism is provided with a pawl seat and an operating device. The operating device includes a fourth operating device, a third operating device, a second operating device and the second end of the first operating device, which are all annular structures. Each ring has and can only control one pawl. For an internal speed hub with more gears, the number of pawls increases accordingly, resulting in a wider width of the shifting pawl seat, which in turn causes the width of the internal speed hub to become wider, and the compatibility with the frame becomes worse.

[0003] Therefore, the existing technology needs to be improved and developed. Utility Model Content

[0004] The purpose of the present application is to provide a shifting mechanism and an internal speed hub, which can shorten the width of the entire internal speed hub.

[0005] In order to solve the above-mentioned technical problems, the present application provides a shift mechanism, including a shift control member, a shift pawl and a shift pawl seat, the shift pawl seat is provided with a shift pawl groove, the shift pawl seat is arranged on the core shaft, the shift pawl is installed in the shift pawl groove, the shift pawl has two states: outward opening and inward retracting, the shift control member is provided with an opening groove, the opening groove is used to control the opening or retracting of the shift pawl, and is used to fix or move the sun gear of the transmission mechanism, the opening groove is provided in the control part, and at least one of the control parts alternately controls the two shift pawls.

[0006] Furthermore, the shift pawl is provided with a second locking portion, a controlled portion, a rotating shaft portion and a retaining spring acting portion, the rotating shaft portion of the shift pawl is installed in the shift pawl groove, and the controlled portion is provided on one side of the shift pawl.

[0007] Further, the shift pawl groove comprises a first shift pawl groove and a second shift pawl groove, and the first shift pawl groove and the second shift pawl groove are alternately arranged in the circumferential direction of the core shaft.

[0008] Further, the shift pawl includes a first shift pawl and a second shift pawl, the first shift pawl is installed in the first shift pawl groove, the second shift pawl is installed in the second shift pawl groove, the protruding direction of the controlled part of the first shift pawl is toward the second shift pawl, the protruding direction of the controlled part of the second shift pawl is toward the first shift pawl, and the controlled part of the first shift pawl and the controlled part of the second shift pawl have a portion overlapping in the circumferential direction of the core shaft between the two shift pawls.

[0009] Further, the shift pawl includes a first shift pawl and a second shift pawl, the first shift pawl and the second shift pawl are installed in the same shift pawl groove, the first shift pawl and the second shift pawl have different lengths, the protruding direction of the controlled part of the first shift pawl is toward the second shift pawl, the protruding direction of the controlled part of the second shift pawl is toward the first shift pawl, and the controlled part of the first shift pawl and the controlled part of the second shift pawl have a part that overlaps in the circumferential direction of the core shaft between the two shift pawls.

[0010] Furthermore, the clamping spring action portion is arranged at the middle portion of the shift pawl.

[0011] Furthermore, at least one sun gear is provided with an extension portion and the outer diameter of the extension portion is greater than or equal to the top circle diameter of the sun gear teeth, and the inner circumferential surface of the extension portion is provided with a locking groove, and the shift pawl is opened and abuts against the locking groove, or the shift pawl is retracted and does not abut against the locking groove.

[0012] Furthermore, the shift control member is provided with a diameter-changing portion, and the outer diameter of the diameter-changing portion is smaller than the outer diameter of other parts of the shift control member.

[0013] The present application also provides an internal speed hub, comprising the above-mentioned shifting mechanism.

[0014] From the above, it can be seen that the shift control member of the shift mechanism can control three shift pawls using two control parts. Compared with each control part only being able to control one shift pawl individually, the length of the shift control member can be further shortened, thereby shortening the width of the entire internal gear hub.

[0015] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a perspective view of a bicycle equipped with an internal gear hub according to Example 1.

[0017] Figure 2 This is a front view of a bicycle equipped with an internal gear hub according to Example 1.

[0018] Figure 3 This is a front view of the rear fork of Example 1.

[0019] Figure 4 It is a schematic structural diagram of the linkage between the shift operator and the internal speed hub in Example 1.

[0020] Figure 5 It is a stereoscopic view of the internal speed hub of Example 1.

[0021] Figure 6 It is a longitudinal sectional view of the internal speed hub of Example 1.

[0022] Figure 7 It is an exploded view of the driving mechanism and the shifting mechanism of Example 1.

[0023] Figure 8 It is a three-dimensional diagram of the resetting device of Example 1.

[0024] Fig. 9 It is a three-dimensional diagram of the shift mechanism of Example 1.

[0025] Fig.10 This is a three-dimensional diagram of the core shaft of Example 1.

[0026] Fig.11 It is a three-dimensional diagram of the shift control component of Example 1.

[0027] Fig.12 This is a three-dimensional view of the shift control component of Example 1 from another angle.

[0028] Fig.13 It is a stereoscopic view of the shift pawl of Example 1.

[0029] Fig.14 This is a three-dimensional view of the shift pawl of Example 1 from another angle.

[0030] Fig.15 This is a schematic diagram of the structure of the second shift pawl and the sun gear in linkage with each other in Example 1.

[0031] Fig.16 This is a stereoscopic view of the sun gear of Example 1.

[0032] Fig.17 It is a longitudinal sectional view of the internal speed hub of Example 2.

[0033] Fig.18 It is a three-dimensional diagram of the shift mechanism of Example 2.

[0034] Description of labels:

[0035] 1-frame, 11-rear fork, 111-first mounting slot, 12-chain, 13-shift operator, 131-handlebar, 14-tensioner, 141-first bracket, 142-connecting arm, 143-connecting rod, 144-guide wheel,

[0036] 2- Output piece,

[0037] 3- End cap,

[0038] 4- Input pieces,

[0039] 5- spindle, 51- limiting surface, 52- limiting groove, 53- shift pawl seat, 54- shift pawl groove, 541- first shift pawl groove, 542- second shift pawl groove, 55- movable groove, 56- retaining spring groove, 561- first retaining spring groove, 562- second retaining spring groove, 563- third retaining spring groove,

[0040] 6-driving mechanism, 61-manual control assembly, 611-second bracket, 612-wire tube, 613-control wire, 614-turntable, 6141-wire slot, 6142-card slot, 6143-limiting member, 62-resetting device, 621-fixing member, 6211-first fixed end, 6212-second fixed end, 622-first resetting member, 63-first connecting member, 631-first connecting part, 632-second connecting part, 64-second connecting member, 641-third connecting part, 642-first connecting slot, 643-fourth connecting part,

[0041] 8-shift mechanism, 81-shift control member, 811-sixth connecting portion, 812-control portion, 812A-first control surface, 812B-second control surface, 8121-first control portion, 8122-second control portion, 813-opening groove, 814-diameter reducing portion, 82-shift pawl, 821-first shift pawl, 822-second shift pawl, 823-third shift pawl, 82A-rotating shaft portion, 82B-controlled portion, 82C-second locking portion, 82D-circlip action portion,

[0042] 9-transmission mechanism, 91-sun gear, 911-locking groove, 912-extension part. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0044] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0045] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0046] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are merely examples, and the purpose is not to limit the utility model. In addition, the utility model may repeat reference numbers and / or reference letters in different examples, and such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0048] Example 1

[0049] Figure 1 The invention shows a schematic structural diagram of a bicycle equipped with an internal speed hub. Figure 2 A front view of a bicycle with an internal gear hub installed is shown. Figure 3 A front view of the rear fork 11 is shown. Figure 4 The schematic diagram of the structure of the shifting operator 13 and the internal speed hub linkage is shown. The internal speed hub is woven on the rim of the rear wheel of the bicycle through spokes, and the mandrel 5 of the internal speed hub is inserted into the first installation groove 111 of the rear fork 11 of the bicycle frame 1. The cross-sectional shape of the first installation groove 111 is an arc at the upper edge and vertical edges on both sides. When installing the internal speed hub, the mandrel 5 of the internal speed hub is vertically inserted into the installation groove of the rear fork 11, and the threads at both ends of the mandrel 5 are tightened by two nuts respectively, so that the mandrel 5 is fixed to the frame 1.

[0050] It should be noted that the internal speed hub can be used not only on bicycles, but also on folding bicycles, Ebikes, electric-assisted bicycles, electric vehicles, electric motorcycles, cargo and freight electric vehicles, tricycles, scooters, electric scooters and other vehicles.

[0051] In the above assembly method, since the distance from the input member 4 to the front sprocket is fixed, the chain 12 cannot be tensioned, or the chain 12 will be stretched after long-term use. Therefore, a tensioner 14 is required to avoid poor engagement and vibration of the chain 12 when the loose side of the chain 12 sags too much.

[0052] like Figure 5 As shown, the tensioner 14 includes a first bracket 141, a connecting arm 142, a connecting rod 143 and a guide wheel 144. A through hole is provided at one end of the first bracket 141 for fixed installation on the right side of the spindle 5. The other end of the first bracket 141 is rotatably connected to the connecting arm 142. A torsion spring is installed between the connecting arm 142 and the first bracket 141. The torsion spring has a certain pre-tightening torque when assembled, which has the function of making the connecting arm 142 rotate to the right side of the spindle 5. Figure 5The end of the connecting arm 142 is provided with a connecting rod 143 with adjustable length, and a guide wheel 144 is rotatably connected to the connecting rod 143. After the chain 12 is installed, the upper side of the chain 12 is the tight side, and the lower side is the loose side. The guide wheel 144 of the tensioner 14 is meshed with the chain 12, and the force generated by the torsion spring of the tensioner 14 acts on the loose side of the chain 12 through the guide wheel 144 to tighten the chain 12, thereby improving the meshing degree, preventing the chain 12 from falling off when riding on a bumpy road, and reducing the noise emitted by the chain 12.

[0053] In order to manually change the transmission ratio of the internal gear hub, it is also necessary to use a shift operator 13 for control. The shift operator 13 is mounted on the handlebar of the bicycle frame 1, and the rider can shift gears by twisting the handlebar 131 of the shift operator 13. The specific structure of the shift operator 13 is consistent with that of the prior art CN207631427U, and will not be described in detail here.

[0054] An input member 4 is fixedly installed on the right side of the internal speed hub, and the input member 4 is used to transmit the torque generated by the rider's pedaling. In the chain transmission system, the input member 4 is a flywheel, and the rider drives the crank by pedaling, thereby driving the rotation of the chain plate, and the chain plate drives the flywheel to rotate through the chain 12, thereby driving the output member 2 to rotate, driving the rear wheel forward; in the belt transmission system, the input member 4 is a rear pulley, and the rider drives the crank by pedaling, thereby driving the rotation of the front pulley, and the front pulley drives the rear pulley to rotate through the belt, thereby driving the output member 2 to rotate, driving the rear wheel forward; in the shaft transmission system, the input member 4 is a bevel gear, and accordingly, the rider outputs torque to the bevel gear through the transmission shaft, driving the output member 2 to rotate.

[0055] Figure 5 A perspective view of an internal gear hub is shown. Figure 6 FIG. 2 shows a longitudinal section of the internal gear hub. Figure 6 In the figure, the right end of the inner speed hub is an end cover 3, and the left end is an output member 2. The end cover 3 cooperates with the output member 2 to form a cavity with a certain sealing property inside, and a shift mechanism 8 and a transmission mechanism 9 are arranged in the cavity. A part of the drive mechanism 6 is located in the cavity, and the other part is located outside the cavity. A mandrel 5 is passed through the center of the inner speed hub, and the drive mechanism 6, the shift mechanism 8 and the transmission mechanism 9 are installed on the mandrel 5 from left to right. The outer peripheral surfaces of both ends of the mandrel 5 are processed with threads for fastening with nuts to the rear fork 11 of the frame 1. The mandrel 5 is also processed with two vertical limiting surfaces 51, both of which are parallel to the axis of the mandrel 5 and parallel to each other. The function of the limiting surfaces 51 is to be assembled on the first mounting groove 111 of the frame 1 for limiting. The shift mechanism 8 is sleeved inside the transmission mechanism 9, and the outer side of the transmission mechanism 9 is connected to the output member 2 to transmit torque.

[0056] Figure 7 An exploded view of the drive mechanism 6 and the shift mechanism 8 is shown. Figure 8 It is a three-dimensional diagram of the resetting device 62.

[0057] The driving mechanism 6 includes a manual control component 61, such as Figure 4 and Figure 5 As shown, the manual control assembly 61 includes a second bracket 611, a wire tube 612, a control wire 613 and a turntable 614. The second bracket 611 is L-shaped. One end of the second bracket 611 is provided with a through hole for installation on the left side of the mandrel 5 and fixedly connected to the mandrel 5. The other end of the second bracket 611 is provided with a limiting hole for fixing the wire tube 612. A control wire 613 is passed through the wire tube 612, one end of the control wire 613 is connected to the shift operator 13, and the other end of the control wire 613 is connected to the turntable 614.

[0058] The turntable 614 is rotatably mounted on the core shaft 5. The outer circumference of the turntable 614 is provided with a wire groove 6141. The control wire 613 is wound in the wire groove 6141. In order to make the turntable 614 and the wire groove 6141 detachably fixed, a clamping groove 6142 is provided on the turntable 614. A limiter 6143 is installed in the clamping groove 6142. The limiter 6143 is fixedly connected to one end of the control wire 613. Figure 4 As shown, when the rider turns the handlebar 131 of the shift operator 13 downward with force, this direction can be defined as a downshift direction, and the shift operator 13 pulls the control line 613 inward for a certain distance, so that the turntable 614 rotates a certain angle in the counterclockwise direction; when the rider turns the handlebar 131 of the shift operator 13 upward, this direction can be defined as an upshift direction, and a release device is provided inside the shift operator 13, which can release the control line 613 for a certain distance, so that the turntable 614 rotates a certain angle in the clockwise direction.

[0059] Since the manual control assembly 61 is located outside the output member 2, and the shift mechanism 8 is located inside the output member 2, in order to allow the rotation of the rotary disk 614 of the manual control assembly 61 to be transmitted to the shift mechanism 8, the drive mechanism 6 also includes a first connecting member 63 and a second connecting member 64. The first connecting member 63 and the second connecting member 64 can be rotatably mounted on the spindle 5. The first connecting member 63 includes a first connecting portion 631 and a second connecting portion 632. The first connecting portion 631 is used to connect the rotary disk 614 of the manual control assembly 61, and the second connecting portion 632 is used to connect the third connecting portion 641 of the second connecting member 64. The second connecting member 64 is provided with a first connecting groove 642 in the middle, and the second connecting member 64 is provided with a fourth connecting portion 643 at one end away from the third connecting portion 641. The fourth connecting portion 643 is connected to the shift mechanism 8 to drive the shift mechanism 8 to shift.

[0060] The first connecting member 63 and the second connecting member 64 can be designed in an integrated manner or in a split manner. In this embodiment, a split design is adopted to facilitate assembly of parts.

[0061] Since there is friction between the wire tube 612 and the control wire 613, especially after long-term use, the inner wall of the wire tube 612 is worn and the friction increases. If the control wire 613 is released entirely by the release device provided inside the shift operator 13, the control wire 613 is likely to be not released in place, resulting in inaccurate shifting or shifting. Therefore, the drive mechanism 6 is also provided with a reset device 62, such as Figure 8 and Fig. 9 As shown, the resetting device 62 includes a fixing member 621 and a first resetting member 622. The fixing member 621 is fixedly connected to the core shaft 5. In the present embodiment, the fixing member 621 is a circular ring structure, and a first fixing end 6211 is arranged on the inner side thereof. Specifically, the first fixing end 6211 is a protrusion with a triangular cross-sectional shape. Correspondingly, a limiting groove 52 matched with the first fixing end 6211 is arranged on the core shaft 5. The fixing member 621 is assembled to the limiting groove 52 of the core shaft 5 by interference fit so that the fixing member 621 cannot move or rotate.

[0062] A first reset member 622 is provided between the fixing member 621 and any one or more of the rotating disk 614, the first connecting member 63, and the second connecting member 64. In the present embodiment, in order to minimize the space occupied by parts, the first reset member 622 is provided between the fixing member 621 and the second connecting member 64. Specifically, the fixing member 621 is provided with avoidance grooves for the rotational movement of the second connecting member 64 on both sides of the circumferential direction of the first fixed end 6211. The second connecting member 64 is rotatably mounted on the core shaft 5. A second fixed end 6212 is provided on one end face of the fixing member 621. The first connecting groove 642 of the second connecting member 64 is provided at a position that is exactly in the same vertical plane as the second fixed end 6212. The second fixed end 6212 of the fixing member 621 is connected to the first connecting groove 642 of the second connecting member 64 via the first reset member 622. The first reset member 622 may adopt a volute spring.

[0063] When the rider turns the handlebar 131 of the shift operator 13 downward with force, the turntable 614, the first connecting member 63, and the second connecting member 64 are driven to rotate counterclockwise to perform a downshift operation, and the first reset member 622 stores elastic force; when the rider turns the handlebar 131 of the shift operator 13 upward, the first reset member 622 releases the elastic force to drive the turntable 614, the first connecting member 63, and the second connecting member 64 to rotate clockwise to perform an upshift operation.

[0064] Fig. 9 It is a three-dimensional diagram of the shift mechanism 8. Fig.10 A perspective view of the mandrel 5 is shown, Fig.11A perspective view of the shift control member 81 is shown, Fig.12 The shift control member 81 is shown in a three-dimensional view from another angle. The shift mechanism 8 includes the shift control member 81, the shift pawl 82 and the shift pawl seat 53. The shift pawl 82 is mounted on the shift pawl seat 53. The shift control member 81 is provided with an opening slot 813. The shift control member 81 is driven to rotate by the driving mechanism 6 to control the shift pawl 82 to be regularly retracted and opened.

[0065] The shift pawl seat 53 and the core shaft 5 can be integral (integrally molded) or split. The split shift pawl seat 53 is easy to process and reduces costs. The integral shift pawl seat 53 has higher strength and precision. In the present embodiment, the shift pawl seat 53 is directly processed on the core shaft 5. The shift pawl seat 53 is arranged along the axial direction of the core shaft 5. The shift pawl seat 53 is provided with a long strip-shaped shift pawl groove 54. A plurality of shift pawls 82 are installed on the shift pawl groove 54. The shift pawl 82 has two states: retracted and opened.

[0066] In this embodiment, in order to realize the control of multiple gears and facilitate assembly, the shift control member 81 is provided with two control parts 812, such as Fig. 9 As shown, it specifically includes a first control part 8121 and a second control part 8122. The first control part 8121 and the second control part 8122 of the shift control member 81 are arranged in sequence from right to left. The second shift pawl 822 and the third shift pawl 823 are installed in the empty space between the first control part 8121 and the second control part 8122, and the first shift pawl 821 is installed in the empty space on the right side of the first control part 8121.

[0067] The shift control component 81 is provided with a sixth connecting portion 811 at its leftmost end, and its function is to be assembled with the driving mechanism 6. After assembly, the driving mechanism 6 outputs torque to the sixth connecting portion 811 to rotate the shift control component 81. Specifically, the fourth connecting portion 643 of the second connecting member 64 of the driving mechanism 6 is directly or indirectly connected to the sixth connecting portion 811 of the shift control component 81 to transmit torque.

[0068] like Fig.11 and Fig.12 As shown, the first control part 8121 and the second control part 8122 are both bent arm structures, and their inner walls are both provided with an opening slot 813, which is used to drive the shift pawl 82 to open and retract. The outer diameters of the first control part 8121 and the second control part 8122 are the same as the outer diameter of the shift pawl seat 53, thereby reducing the radial size of the shift control member 81 and making the entire internal gear hub more compact.

[0069] In order to enable the control part 812 of the shift control member 81 to be assembled on the shift pawl seat 53 and to be able to rotate around the core shaft 5, the shift pawl seat 53 is provided with a plurality of movable grooves 55. The movable grooves 55 are arranged along the circumference of the shift pawl seat 53. There are two movable grooves 55, each for accommodating the control part 812. When the shift control member 81 is assembled to the pawl seat, the two control parts 812 of the shift control member 81 are both in the movable grooves 55, and the shift control member 81 can rotate around the axis of the core shaft 5.

[0070] The shift pawl seat 53 is also provided with a plurality of retaining spring grooves 56, in which retaining springs (not shown) are installed. The retaining springs are installed on the outside of the retaining spring action portion 82D of the shift pawl 82. When assembled, the retaining springs remain in a contracted state and have a tendency to open outward. Tension can be applied to the shift pawl 82 to keep the shift pawl 82 open outward. The shift pawl 82 will only retract inward when it is subjected to a force in a specific direction.

[0071] In this embodiment, there are three retaining spring grooves 56, including a first retaining spring groove 561, a second retaining spring groove 562 and a third retaining spring groove 563. The retaining spring assembled in the first retaining spring groove 561 acts on the retaining spring action part 82D of the first shift pawl 821, the retaining spring assembled in the second retaining spring groove 562 acts on the retaining spring action part 82D of the second shift pawl 822, and the retaining spring assembled in the third retaining spring groove 563 acts on the retaining spring action part 82D of the third shift pawl 823.

[0072] The control part 812 is provided with an opening groove 813 on its inner wall, and the control part 812 is formed with a first control surface 812A on the opening groove 813, and the shift pawl 82 is controlled to open by the first control surface 812A. The control part 812 is provided with a second control surface 812B, and the second control surface 812B is an arc surface, and the shift pawl 82 is controlled to retract by the second control surface 812B. Since the opening groove 813 is provided, when the shift control member 81 rotates, the opening groove 813 slides to the position of the controlled part 82B of the shift pawl 82, and the controlled part 82B of the shift pawl 82 has space to move, and the shift pawl 82 opens outward under the action of the retaining spring, and after the second control surface 812B slides to the position of the shift pawl 82, the controlled part 82B of the shift pawl 82 is pressed down, thereby realizing the function of opening and retracting the shift pawl 82.

[0073] In order to reduce the width of the shift pawl seat 53, and thus reduce the width of the internal gear hub, and adapt to frames with wheel diameters of 24 inches, 20 inches and below, the shift pawl groove 54 is split into two, namely a first shift pawl groove 541 and a second shift pawl groove 542. The first shift pawl groove 541 and the second shift pawl groove 542 are staggered in the circumferential direction of the core shaft 5, wherein the first shift pawl groove 541 is used to assemble the first shift pawl 821, and the second shift pawl groove 542 is used to assemble the second shift pawl 822 and the third shift pawl 823.

[0074] The structure of the shift pawl 82 is as follows: Fig.13 and Fig.14 As shown, the shift pawl 82 is provided with a second locking portion 82C, a controlled portion 82B, a rotating shaft portion 82A and a clamping spring acting portion 82D, the rotating shaft portion 82A is provided at the bottom of the second locking portion 82C, the rotating shaft portion 82A is in the shape of a half cylinder, the first shift pawl groove 541 and the second shift pawl groove 542 are both adapted to the shape of the rotating shaft portion 82A, and the rotating shaft portion 82A is hinged in the shift pawl groove 54 to allow the shift pawl 82 to rotate around the axis of the rotating shaft portion 82A. The second locking portion 82C of the shift pawl 82 is used to fix or move the sun gear 91 in the transmission mechanism 9.

[0075] The controlled portion 82B of the first shift pawl 821 is arranged on one side of the first shift pawl 821 and protrudes along the thickness direction of the second locking portion 82C. The protruding direction of the controlled portion 82B of the first shift pawl 821 faces the second shift pawl 822. The second shift pawl 822 is substantially the same as the first shift pawl 821, except that the protruding direction of the controlled portion 82B of the second shift pawl 822 faces the first shift pawl 821. The advantage of such arrangement is that the controlled portion 82B of the first shift pawl 821 and the controlled portion 82B of the second shift pawl 822 have a portion overlapping in the circumferential direction of the spindle 5 between the two shift pawls 82, so the two shift pawls 82 can be alternately controlled by at least one control portion 812 of the shift control member 81. In this embodiment, two control parts 812 can control three shift pawls 82. Compared with each control part 812 only being able to control one shift pawl 82, the length of the shift control member 81 can be further shortened, thereby shortening the width (axial length) of the entire internal gear hub.

[0076] It should be noted that, since the first control portion 8121 needs to alternately control the first shift pawl 821 and the second shift pawl 822 , the slot length of the opening slot 813 provided in the first control portion 8121 also needs to be lengthened accordingly.

[0077] In certain preferred embodiments, the first shift pawl 821 and the second shift pawl 822 can be installed on the same shift pawl groove 54, for example, at the same time installed on the second shift pawl groove 542. Since it is required that the controlled portion 82B of the first shift pawl 821 and the controlled portion 82B of the second shift pawl 822 have a portion overlapping in the circumferential direction of the core shaft 5 between the two shift pawls 82, the lengths of the first shift pawl 821 and the second shift pawl 822 can be different. The length of the shift pawl 82 refers to the distance from the rotating shaft portion 82A to the second locking portion 82C.

[0078] The retaining spring acting portion 82D of the second shift pawl 822 is arranged on the other side relative to the controlled portion 82B, and the retaining spring acting portion 82D will occupy a certain width. In order to further reduce the width of the shift pawl seat 53, the pawl at the right end of the shift control member 81, that is, the first shift pawl 821, has the retaining spring acting portion 82D arranged in the middle of the first shift pawl 821. Because the retaining spring acting portion 82D is arranged in the middle of the first shift pawl 821, the retaining spring will not interfere with the shift control member 81 after assembly, and the width of the first shift pawl 821 and the width of the shift pawl seat 53 are also further reduced, thereby shortening the width (axial length) of the entire inner gear hub.

[0079] Fig.15 Schematic diagram of the structure of the second shift pawl 822 and the sun gear 91. When the second shift pawl 822 is opened, the second locking portion 82C of the second shift pawl 822 abuts against the locking groove 911 on the inner circumference of the sun gear 91, and the sun gear 91 is fixed; when the second shift pawl 822 is retracted, the second locking portion 82C of the second shift pawl 822 does not abut against the locking groove 911 of the sun gear 91, and the sun gear 91 moves. One shift pawl 82 controls one sun gear 91.

[0080] By controlling the shift control member 81 to rotate to different angles, different shift pawls 82 are controlled to open or retract, thereby switching to different gears.

[0081] In some embodiments, in order to ensure that the strength meets the standard and has a smaller transmission ratio, an extension portion 912 is provided on one side of the gear teeth of the sun gear 91, such as Fig.16 As shown, the extension portion 912 is cylindrical, the outer diameter of the extension portion 912 is larger than the diameter of the tooth top circle of the sun gear 91, the inner diameter of the extension portion 912 is slightly larger than the outer diameter of the shift control member 81, and the inner circumferential surface of the extension portion 912 is provided with a locking groove 911 adapted to the shift pawl 82.

[0082] The first control portion 8121 of the shift control member 81 can extend into the inner side of the extension portion 912 of the sun gear 91, and control the locking and rotation of the sun gear 91 by controlling the opening and retraction of the first shift pawl 821. Preferably, the extension section is arranged on a side close to the drive mechanism 6, so that the overall length of the shift control member 81 can be reduced.

[0083] Example 2

[0084] Fig.17 This is a longitudinal section view of the internal gear hub. Fig.18 8 is a three-dimensional diagram of the shift mechanism 8. The difference between the second embodiment and the first embodiment is that an additional shift pawl 82 is provided. In order to control four shift pawls 82 under the premise of the same width of the internal gear hub, the shift control member 81 of the shift mechanism 8 is provided with a diameter reducing portion 814, and the diameter reducing portion 814 is provided with a control portion 812 for controlling the shift pawl 82, such as Fig.18 As shown, the outer diameter of the diameter reducing portion 814 is smaller than the outer diameter of other parts of the shift control member 81, and the outer diameter of the shift pawl seat 53 inside the diameter reducing portion 814 is also reduced accordingly, and the thickness of the sun gear 91 can be increased to a size that meets the strength requirements. In embodiment 1, an extension portion 912 is provided on one side of the gear teeth of the sun gear 91, and a locking groove 911 is provided on the inner circumference of the extension portion 912. In this embodiment, the locking groove 911 is directly provided on the inner circumference of the sun gear 91, so that the shift control member 81 can control the first shift pawl 821 and ensure the strength of the sun gear 91, and has one more gear than embodiment 1.

[0085] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0086] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A shift mechanism, comprising a shift control member (81), a shift pawl (82) and a shift pawl seat (53), wherein the shift pawl seat (53) is provided with a shift pawl groove (54), the shift pawl seat (53) is arranged on a core shaft (5), the shift pawl (82) is installed in the shift pawl groove (54), and the shift pawl (82) has two states: outwardly opened and inwardly retracted, characterized in that: The shift control member (81) is provided with an opening slot (813), and the opening slot (813) is used to control the shift pawl (82) to open or retract, and is used to fix or move the sun gear (91) of the transmission mechanism (9). The opening slot (813) is provided in the control unit (812), and at least one of the control units (812) alternately controls the two shift pawls (82).

2. The shift mechanism according to claim 1, characterized in that: The shift pawl (82) is provided with a second locking portion (82C), a controlled portion (82B), a rotating shaft portion (82A) and a retaining spring acting portion (82D); the rotating shaft portion (82A) of the shift pawl (82) is installed in the shift pawl groove (54), and the controlled portion (82B) is provided on one side of the shift pawl (82).

3. The shift mechanism according to claim 2, characterized in that: The shift pawl groove (54) comprises a first shift pawl groove (541) and a second shift pawl groove (542), and the first shift pawl groove (541) and the second shift pawl groove (542) are alternately arranged in the circumferential direction of the core shaft (5).

4. The shift mechanism according to claim 3, characterized in that: The shift pawl (82) comprises a first shift pawl (821) and a second shift pawl (822), wherein the first shift pawl (821) is installed in the first shift pawl groove (541), and the second shift pawl (822) is installed in the second shift pawl groove (542), the protruding direction of the controlled portion (82B) of the first shift pawl (821) is toward the second shift pawl (822), and the protruding direction of the controlled portion (82B) of the second shift pawl is toward the first shift pawl (821), and the controlled portion (82B) of the first shift pawl (821) and the controlled portion (82B) of the second shift pawl have a portion overlapping in the circumferential direction of the core shaft (5) between the two shift pawls (82).

5. The shift mechanism according to claim 2, characterized in that: The shift pawl (82) comprises a first shift pawl (821) and a second shift pawl (822). The first shift pawl (821) and the second shift pawl (822) are installed in the same shift pawl groove (54). The first shift pawl (821) and the second shift pawl (822) have different lengths. The protruding direction of the controlled portion (82B) of the first shift pawl (821) faces the second shift pawl (822), and the protruding direction of the controlled portion (82B) of the second shift pawl faces the first shift pawl (821). The controlled portion (82B) of the first shift pawl (821) and the controlled portion (82B) of the second shift pawl have a portion overlapping in the circumferential direction of the core shaft (5) between the two shift pawls (82).

6. The shift mechanism according to claim 2, characterized in that: The clamping spring acting portion (82D) is arranged at the middle portion of the shift pawl (82).

7. The shift mechanism according to claim 1, characterized in that: At least one sun gear (91) is provided with an extension portion (912) and the outer diameter of the extension portion (912) is greater than or equal to the tooth top circle diameter of the gear teeth of the sun gear (91), and the inner circumferential surface of the extension portion (912) is provided with a locking groove (911), and the shift pawl (82) is opened to abut against the locking groove (911), or the shift pawl (82) is retracted and does not abut against the locking groove (911).

8. The shift mechanism according to claim 1, characterized in that: The shift control member (81) is provided with a diameter reducing portion (814), and the outer diameter of the diameter reducing portion (814) is smaller than the outer diameter of other parts of the shift control member (81).

9. An internal speed hub, characterized in that: The invention comprises the shifting mechanism as described in any one of claims 1 to 8.

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