Drive unit for human-powered vehicle

Abstract

To provide a drive unit for a human-powered vehicle that can suppress concentration of stress.SOLUTION: A drive unit for a human-powered vehicle comprises: a housing including a mounting part that can be mounted on a frame of the human-powered vehicle by a fastener; and a connecting member provided on the mounting part and is constituted to be connected to the faster. The mounting part has: an internal surface penetrating through the mounting part and regulating a mounting part through-hole in which the connection member is arranged in a space; and a first mounting part end face opposing to the frame, in an axial direction of the mounting part with respect to a central axis center of the mounting part through-hole of the mounting part through-hole. The connection member has: a connection member through-hole which penetrates through the connection member and can be inserted through the fastener; and a first connection member end face formed at the frame side, in the axial direction of the mounting part in a mounted state where the mounting part is mounted on the frame. The first mounting part end face is positioned closer to the frame than the first connection member end face, in the axial direction of the mounting part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to technology for drive units for human-powered vehicles. [Background technology]

[0002] Conventionally, drive units for human-powered vehicles are known. For example, Patent Document 1 discloses a technology for a drive unit that includes a housing including a mounting portion that can be attached to the frame of the human-powered vehicle, and a cylindrical connecting member that is inserted into the mounting portion. A crankshaft is inserted into the housing. The connecting member is exposed to the outside of the housing from the mounting portion and comes into contact with the frame. The mounting portion is attached to the frame by a bolt that is threaded into the connecting member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US2023 / 0322327A1 publication Summary of the Invention [Problem to be solved by the invention]

[0004] When a manual driving force is input to the crankshaft, a load acts on the housing. In conventional drive units, the connecting member is exposed to the outside of the housing from the mounting portion and comes into contact with the frame, so when a load acts on the housing, the load is likely to act on the connecting member. Because the load is likely to act on the connecting member, conventional drive units are prone to stress concentration around the connecting member at the mounting portion.

[0005] An object of the present disclosure is to provide a drive unit that can suppress stress concentration. [Means for solving the problem]

[0006] A drive unit according to a first aspect of the present disclosure is a drive unit for a human-powered vehicle, comprising: a housing including an attachment portion attachable to a frame of the human-powered vehicle with a fastener; and a connecting member provided on the attachment portion and configured to connect to the fastener; the attachment portion has an inner surface that defines an attachment portion through hole that penetrates the attachment portion and in which the connecting member is disposed in the internal space, and a first attachment portion end face that faces the frame in an attachment portion axial direction related to the central axis of the attachment portion through hole; the connecting member has a connecting member through hole that penetrates the connecting member and through which the fastener can be inserted, and a first connecting member end face formed on the frame side in the attachment portion axial direction in an attachment state in which the attachment portion is attached to the frame; and the first attachment portion end face is located closer to the frame than the first connecting member end face in the attachment portion axial direction. According to the drive unit of the first aspect, when a load acts on the housing, the load is less likely to act on the connecting member, so stress concentration can be suppressed.

[0007] In the drive unit of the second aspect according to the first aspect, the inner surface of the mounting portion includes a first overlapping portion that covers at least a portion of the end surface of the first connecting member. According to the drive unit of the second aspect, the first overlapping portion can suppress movement of the connecting member along the axial direction of the mounting portion, thereby further suppressing stress concentration.

[0008] In the drive unit of the third side surface according to the second side surface, the first overlapping portion covers the entire end surface of the first connecting member. According to the drive unit of the third aspect, movement of the connecting member along the axial direction of the mounting portion can be further suppressed, thereby further suppressing stress concentration.

[0009] In the drive unit of the fourth side surface according to the second or third side surface, the first overlapping portion contacts at least a portion of the end surface of the first connecting member in the attachment portion axial direction. According to the drive unit of the fourth aspect, movement of the connecting member along the axial direction of the mounting portion can be further suppressed, thereby further suppressing stress concentration.

[0010] In a drive unit of a fifth side face according to any one of the first to fourth sides, the connecting member further has a second connecting member end face opposite the first connecting member end face in the mounting portion axial direction, and an outer surface connecting the first connecting member end face and the second connecting member end face, the outer surface including at least one outer protrusion protruding from the outer surface in a mounting portion radial direction relative to the central axis of the mounting portion through hole of the mounting portion through hole, the inner surface including at least one inner protrusion protruding from the inner surface in the mounting portion radial direction and positioned between the first connecting member end face and the second connecting member end face in the mounting portion axial direction, and the at least one outer protrusion and the at least one inner protrusion are adjacent in the mounting portion axial direction. According to the drive unit of the fifth aspect, at least one outer protrusion and at least one inner protrusion can suppress movement of the connecting member along the axial direction of the mounting portion, thereby further suppressing stress concentration.

[0011] In the drive unit of the sixth aspect according to the fifth aspect, the at least one outer protrusion includes a plurality of outer protrusions, and the plurality of outer protrusions are arranged at intervals from one another in the axial direction of the mounting portion. According to the drive unit of the sixth aspect, movement of the connecting member along the axial direction of the mounting portion can be further suppressed, thereby further suppressing stress concentration.

[0012] In a drive unit of a seventh side according to either the fifth or sixth side, at least one outer protrusion has a radial end portion in the radial direction of the mounting portion and an inclined surface that approaches the radial end portion in the radial direction of the mounting portion as it moves toward the radial end portion in the axial direction of the mounting portion. According to the drive unit of the seventh aspect, at least one inner protrusion contacts the inclined surface, thereby distributing stress to the contact surface.

[0013] In the drive unit of the eighth side according to the seventh side, the radial end is positioned between the end face of the first connecting member and the inclined surface in the axial direction of the mounting portion, and the inclined surface is adjacent to the radial end in the axial direction of the mounting portion. According to the drive unit of the eighth aspect, movement of the connecting member from the frame side toward the opposite side of the frame in the axial direction of the attachment portion can be suppressed, thereby further suppressing stress concentration.

[0014] In a drive unit having a ninth side surface according to any one of the first to eighth sides, the mounting portion further has a second mounting portion end face opposite the first mounting portion end face in the mounting portion axial direction, and the connecting member further has a second connecting member end face opposite the first connecting member end face in the mounting portion axial direction, and the second mounting portion end face is located on the opposite side of the frame from the second connecting member end face in the mounting portion axial direction. According to the drive unit of the ninth aspect, a load is less likely to act on the end face of the second connecting member, so that stress concentration can be suppressed.

[0015] In the drive unit of a tenth aspect according to the ninth aspect, the inner surface of the mounting portion includes a second overlapping portion that covers at least a portion of the end surface of the second connecting member. According to the drive unit of the tenth aspect, the second overlapping portion can suppress movement of the connecting member along the axial direction of the mounting portion, thereby further suppressing stress concentration.

[0016] In the drive unit of the eleventh aspect according to the tenth aspect, the second overlapping portion covers the entire end surface of the second connecting member. According to the drive unit of the eleventh aspect, movement of the connecting member along the axial direction of the mounting portion can be further suppressed, thereby further suppressing stress concentration.

[0017] In the drive unit of the twelfth aspect according to the tenth or eleventh aspect, the second overlapping portion contacts at least a part of the end surface of the second connecting member in the attachment portion axial direction. According to the drive unit of the twelfth aspect, movement of the connecting member along the axial direction of the mounting portion can be further suppressed, thereby further suppressing stress concentration.

[0018] In a drive unit having a thirteenth side surface conforming to any one of the first to twelfth sides, the inner surface is formed cylindrically when viewed from the axial direction of the mounting portion, the connecting member is formed cylindrically with a central axis, and the drive unit has a regulating portion that regulates circumferential rotation about the central axis of the mounting portion through hole. According to the drive unit of the thirteenth aspect, the rotation of the connecting member can be restricted by the restricting portion.

[0019] In a drive unit of a 14th side according to the 13th side, the regulating portion has a first engaging portion formed on the outer peripheral surface of the connecting member and a second engaging portion formed on the inner surface and engaging with the first engaging portion in the circumferential direction. According to the drive unit of the fourteenth aspect, the first engaging portion and the second engaging portion can restrict rotation of the connecting member.

[0020] In a drive unit of a fifteenth aspect according to the fourteenth aspect, the first engagement portion and the second engagement portion include knurling. According to the drive unit of the fifteenth aspect, the knurling can restrict rotation of the connecting member.

[0021] In a drive unit of a 16th side according to the 14th or 15th side, the first engagement portion includes at least one first flat portion formed on at least a portion of the outer peripheral surface of the connecting member, and the second engagement portion includes at least one second flat portion formed on at least a portion of the inner surface. According to the drive unit of the sixteenth aspect, the rotation of the connecting member can be restricted by at least one first flat portion and at least one second flat portion. [Effects of the Invention]

[0022] According to the drive unit of the present disclosure, stress concentration can be suppressed. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 2 is a side view showing the drive unit and the frame according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line D2-D2 in FIG. [Figure 3] FIG. 4 is a cross-sectional view showing a first protrusion and a first attachment portion. [Figure 4] FIG. 4 is a cross-sectional view showing a second protruding portion and a second mounting portion. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. 10 is a perspective view showing a connecting member on which a knurling is formed. [Figure 11] 3A and 3B are cross-sectional views showing at least one first flat portion and at least two first flat portions. [Figure 12] FIG. 4 is a perspective view showing a connecting member on which at least one first flat portion is formed. [Figure 13] FIG. 10 is a side view showing a connecting member with a portion exposed from the mounting portion. [Figure 14] 14 is a cross-sectional view taken along line D14-D14 in FIG. 13. DETAILED DESCRIPTION OF THE INVENTION

[0024] (First embodiment) A drive unit 9 for a human-powered vehicle according to the first embodiment will be described. Figures 1 to 8 will be used to describe the drive unit 9 for a human-powered vehicle according to the first embodiment.

[0025] A human-powered vehicle is a vehicle that has at least one wheel and can be propelled at least by human driving force. Human-powered vehicles include various types of bicycles, such as mountain bikes, road bikes, city bikes, cargo bikes, hand bikes, and recumbents. There is no limit to the number of wheels a human-powered vehicle has. Human-powered vehicles include, for example, unicycles and vehicles with two or more wheels. Human-powered vehicles are not limited to vehicles that can be propelled solely by human driving force. Human-powered vehicles include E-bikes that use not only human driving force but also the driving force of an electric motor M for propulsion. E-bikes include electrically assisted bicycles whose propulsion is assisted by an electric motor M. In the following embodiments, a human-powered vehicle will be described as an electrically assisted bicycle.

[0026] As shown in FIG. 1, the human-powered vehicle includes a frame 1. FIG. 1 is a view of the frame 1 and drive unit 9 as seen from the right side of the human-powered vehicle in a horizontal position with all of the wheels of the human-powered vehicle in contact with the horizontal ground. In FIG. 1, the frame 1 is depicted schematically. The frame 1 has a down tube 2, a seat tube 3, a chainstay 4, and a support portion 5. The support portion 5 is configured to support the drive unit 9. The support portion 5 is provided, for example, in a portion of the frame 1 where the down tube 2, the seat tube 3, and the chainstay 4 are connected to one another. The support portion 5 is formed to fit along a portion of the outer edge of the drive unit 9. The support portion 5 may be formed integrally with the frame 1 as a single member, or may be formed separately from the frame 1 and attached to it.

[0027] In this specification, the following directional terms "front," "rear," "forward," "backward," "left," "right," "sideways," "upward," and "downward," as well as any other similar directional terms, refer to those directions determined with reference to a rider facing the handlebars in a reference position on the human-powered vehicle (e.g., on the saddle or seat).

[0028] As shown in FIG. 2, the cross section of the support portion 5 is formed in an inverted U shape. The support portion 5 has an extension portion 6, a first protruding portion 7, and a second protruding portion 8. The extension portion 6 is formed so as to extend along part of the outer edge of the drive unit 9. The first protruding portion 7 and the second protruding portion 8 are formed so as to protrude from the extension portion 6. The first protruding portion 7 and the second protruding portion 8 are arranged so as to overlap part of the drive unit 9 in a side view when in a horizontal position. The first protruding portion 7 and the second protruding portion 8 are arranged at a distance from each other in the left-right direction of the human-powered vehicle when in a horizontal position.

[0029] The first protrusion 7 is formed at the right end of the support part 5 when in a horizontal position. The first protrusion 7 has a first inner surface 7a and a plurality of first mounting holes 7b. The first inner surface 7a is arranged to face the inside of the left and right sides of the human-powered vehicle when in a horizontal position. The plurality of first mounting holes 7b are formed in a shape that allows fasteners F to be attached from the outside of the first protrusion 7 on the left and right sides when in a horizontal position.

[0030] The fastener F is configured to connect multiple components to one another. For example, the fastener F is inserted through multiple components. In this embodiment, the fastener F is inserted through an attachment portion 30 of the drive unit 9 that can be attached to the frame 1, and through the first protrusion 7 of the frame 1. The attachment portion 30 is fastened to the first protrusion 7 by the fastener F, thereby connecting the first protrusion 7 and the attachment portion 30 to one another. The fastener F includes, for example, at least one of a bolt and a rivet. In FIG. 1, the fastener F is omitted from the illustration.

[0031] The multiple first mounting holes 7b penetrate the first protrusion 7 along the left-right direction of the human-powered vehicle when it is in a horizontal position. As shown in Fig. 1, in this embodiment, the multiple first mounting holes 7b include three first mounting holes 7b. The number of first mounting holes 7b is not limited to this embodiment.

[0032] The second protrusion 8 shown in FIG. 2 is formed at the left end of the support portion 5 when the vehicle is in a horizontal position. The second protrusion 8 has a second inner surface 8a and multiple second mounting holes 8b. The second inner surface 8a is arranged to face the inside of the left and right sides of the human-powered vehicle when the vehicle is in a horizontal position. The multiple second mounting holes 8b are formed in the same manner as the multiple first mounting holes 7b. The multiple second mounting holes 8b are arranged coaxially with the multiple first mounting holes 7b. Like the first protrusion 7, the second protrusion 8 is connected to the drive unit 9 by fasteners F.

[0033] The drive unit 9 is configured to provide propulsive force to the human-powered vehicle. As shown in Fig. 2 and Fig. 5, the drive unit 9 is for a human-powered vehicle and includes a housing 10 including a mounting portion 30 that can be attached to the frame 1 of the human-powered vehicle with fasteners F, and a connecting member 60 that is provided on the mounting portion 30 and configured to connect to the fasteners F. Fig. 5 is a view of the drive unit 9 as seen from the right of the human-powered vehicle in a horizontal position. In this embodiment, the drive unit 9 further includes a plurality of adjustment members 90.

[0034] The housing 10 is formed to be hollow. The housing 10 is made of, for example, magnesium. In this embodiment, the housing 10 is formed by connecting two parts to each other. One of the two parts forms the right side of the housing 10 in an attached state where the mounting portion 30 is attached to the frame 1 and in a horizontal position. The other of the two parts forms the left side of the housing 10 in an attached state and in a horizontal position. The housing 10 includes two side surfaces 20 and the mounting portion 30.

[0035] The two side surfaces 20 form the outer surfaces of the housing 10. One of the two side surfaces 20 forms the outer surface of the right side of the housing 10 in an attached and horizontal state. In this specification, one of the two side surfaces 20 is referred to as a first side surface 21. In this embodiment, the first side surface 21 is the outer surface of one of the two components that form the housing 10. As shown in FIG. 5 , the first side surface 21 includes a first through hole 21a. The first through hole 21a is formed so that the input rotation shaft AR and the output rotation shaft can be inserted therethrough.

[0036] The input rotation shaft AR is a shaft that rotates when a human-powered driving force is input. The input rotation shaft AR has a rotation center axis RCA. The input rotation shaft AR includes, for example, a crankshaft. Crank arms are provided at both ends of the input rotation shaft AR in the axial direction relative to the rotation center axis RCA. The output rotation shaft is a shaft to which the human-powered driving force and the motor driving force from the electric motor M arranged in the internal space of the housing 10 are transmitted. The output rotation shaft is arranged coaxially with the input rotation shaft AR. The first through hole 21a is formed in a circular shape when viewed from the left and right of the human-powered vehicle in the installed and horizontal state.

[0037] The other of the two side surfaces 20 shown in FIG. 2 constitutes the outer surface of the left side of the housing 10 in the mounted and horizontal state. In this specification, the other of the two side surfaces 20 is referred to as the second side surface 22. In this embodiment, the second side surface 22 is the outer surface of the other of the two components constituting the housing 10. As shown in FIG. 5, the second side surface 22 includes a second through hole 22a. The second through hole 22a is formed so that the input rotation shaft AR can be inserted therethrough. The second through hole 22a is formed in a circular shape when viewed from the left and right direction of the human-powered vehicle in the mounted and horizontal state. The second through hole 22a is arranged coaxially with the first through hole 21a. The inner diameter of the second through hole 22a is smaller than the inner diameter of the first through hole 21a.

[0038] The mounting portions 30 are provided on the two side surfaces 20. When viewed from the left and right of the human-powered vehicle in an attached and horizontal state, the mounting portions 30 are formed so as to protrude from the two side surfaces 20. As shown in FIG. 2 , when attached, the mounting portions 30 are disposed in the internal space of the support portion 5. In this specification, the mounting portion 30 provided on the first side surface 21 that constitutes the right surface of the housing 10 is referred to as the first mounting portion 40. In this specification, the mounting portion 30 provided on the second side surface 22 that constitutes the left surface of the housing 10 is referred to as the second mounting portion 50.

[0039] As shown in Fig. 5, a plurality of first mounting portions 40 are provided on the first side surface 21. In this embodiment, the number of first mounting portions 40 is equal to the number of first mounting holes 7b of the first protrusion 7 shown in Fig. 1. In this embodiment, a plurality of second mounting portions 50 are provided on the second side surface 22. The plurality of second mounting portions 50 are arranged to the left of the first mounting portion 40 at intervals in the mounted and horizontal state.

[0040] As shown in FIG. 2 , the mounting portion 30 has inner surfaces 42, 52 that define mounting portion through holes 41, 51 that penetrate the mounting portion 30 and in which the connecting member 60 is disposed, and first mounting portion end faces 43, 53 that face the frame 1 in a mounting portion axial direction relative to the central axes of the mounting portion through holes 41, 51. In this embodiment, the mounting portion through hole central axes include a first central axis CA1 of the mounting portion through hole 41 and a second central axis CA2 of the mounting portion through hole 51. The mounting portion axial direction includes a first axial direction AD1 relative to the first central axis CA1 and a second axial direction AD2 relative to the second central axis CA2. The mounting portion axial direction is parallel to the axial direction relative to the rotation central axis RCA of the input rotation shaft AR when the input rotation shaft AR is inserted through the first through hole 21 a and the second through hole 22 a. The mounting portion axial direction is a direction parallel to the left-right direction of the human-powered vehicle when the mounting portion 30 is mounted and horizontal. In this embodiment, the mounting portion 30 further has second mounting portion end faces 44, 54 on the opposite side of the first mounting portion end faces 43, 53 in the mounting portion axial direction.

[0041] A plurality of first mounting portions 40 will be described. Figures 3 and 6 show one of the plurality of first mounting portions 40. Since the plurality of first mounting portions 40 are configured similarly to one another, in this specification, the first mounting portion 40 shown in Figures 3 and 6 will be described, and a description of the remaining first mounting portions 40 not shown in Figures 3 and 6 will be omitted. The first mounting portion 40 is a portion of the housing 10 that can be attached to the first protrusion 7 of the frame 1. The first mounting portion 40 has an inner surface 42, a first mounting portion end face 43, and a second mounting portion end face 44.

[0042] The inner surface 42 defines an attachment portion through hole 41 having a first central axis CA1. When viewed in the first axial direction AD1, the attachment portion through hole 41 is arranged coaxially with the first attachment hole 7b of the first protrusion 7. The inner surface 42 is formed into a cylindrical shape when viewed in the attachment portion axial direction. As shown in FIG. 3 , the inner diameter of the inner surface 42 varies depending on the position in the first axial direction AD1.

[0043] The first mounting portion end face 43 is a face that faces the first inner side surface 7a of the first protrusion 7 in the mounted state. In this embodiment, the first mounting portion end face 43 is a face that faces to the right of the human-powered vehicle in the mounted state and in a horizontal position. The first mounting portion end face 43 comes into contact with the first inner side surface 7a of the first protrusion 7 in the mounted state. The second mounting portion end face 44 is a face that faces to the left of the human-powered vehicle in the mounted state and in a horizontal position.

[0044] A plurality of second mounting portions 50 will be described. One of the plurality of second mounting portions 50 is depicted in FIG. 4. Since the plurality of second mounting portions 50 are configured similarly to one another, in this specification, the second mounting portion 50 shown in FIG. 4 will be described, and a description of the remaining second mounting portions 50 not shown in FIG. 4 will be omitted. The second mounting portion 50 is a portion of the housing 10 that can be attached to the second protrusion 8 of the frame 1. The second mounting portion 50 has an inner surface 52, a first mounting portion end face 53, and a second mounting portion end face 54.

[0045] The inner surface 52 defines the mounting portion through hole 51 having a second central axis CA2. As shown in FIG. 2, the second central axis CA2 coincides with the first central axis CA1 of the first mounting portion 40. The inner surface 52 is formed in a cylindrical shape with a larger inner diameter than the inner surface 42 of the first mounting portion 40 when viewed in the second axial direction AD2. The inner diameter of the inner surface 52 varies depending on the position in the second axial direction AD2.

[0046] 4, the first mounting end surface 53 is a surface that faces the second inner surface 8a of the second protrusion 8 in the mounted state. In this embodiment, the first mounting end surface 53 is a surface that faces the left of the human-powered vehicle in the mounted state and in a horizontal position. The second mounting end surface 54 is a surface that faces the right of the human-powered vehicle in the mounted state and in a horizontal position.

[0047] 2, an end face width W1 along the attachment portion axial direction from the first attachment portion end face 53 of the second attachment portion 50 to the first attachment portion end face 43 of the first attachment portion 40 is smaller than an inner face width W2 along the attachment portion axial direction from the first inner face 7a of the first protrusion 7 to the second inner face 8a of the second protrusion 8. In this embodiment, the end face width W1 is smaller than the inner face width W2, and the first attachment portion end face 43 contacts the first inner face 7a of the first protrusion 7, so that the first attachment portion end face 53 is disposed at a distance from the second inner face 8a of the second protrusion 8 in the second axial direction AD2 in the attached state.

[0048] The connecting member 60 is disposed in the internal space of the mounting portion 30. The connecting member 60 is made of aluminum, for example. The connecting member 60 may be formed integrally with the mounting portion 30 as a single member by insert molding. In this specification, the connecting members 60 disposed in the internal spaces of the plurality of first mounting portions 40 are referred to as a plurality of first connecting members 70. In this specification, the connecting members 60 disposed in the internal spaces of the plurality of second mounting portions 50 are referred to as a plurality of second connecting members 80.

[0049] As shown in FIGS. 3 and 4 , the connecting member 60 has connecting member through holes 71, 81 that penetrate the connecting member 60 and through which fasteners F can be inserted, and first connecting member end faces 72, 82 that are formed on the frame 1 side in the attachment portion axial direction when the attachment portion 30 is attached to the frame 1. In this embodiment, the connecting member 60 further has second connecting member end faces 73, 83 that are opposite the first connecting member end faces 72, 82 in the attachment portion axial direction, and outer surfaces 74, 84 that connect the first connecting member end faces 72, 82 and the second connecting member end faces 73, 83. As shown in FIGS. 7 and 8 , the connecting member 60 is formed in a cylindrical shape with a central axis. The central axis of the connecting member 60 coincides with the central axis of the attachment portion through hole.

[0050] A plurality of first connecting members 70 will be described. FIGS. 3 and 7 show one of the plurality of first connecting members 70. Because the plurality of first connecting members 70 are configured similarly to one another, the first connecting member 70 shown in FIGS. 3 and 7 will be described in this specification, and a description of the remaining first connecting members 70 not shown in FIGS. 3 and 7 will be omitted. The length of the first connecting member 70 along the first axial direction AD1 is shorter than the length of the first mounting portion 40 along the first axial direction AD1. The first connecting member 70 has a connecting member through hole 71, a first connecting member end face 72, a second connecting member end face 73, and an outer surface 74.

[0051] The connecting member through hole 71 penetrates the first connecting member 70 in the first axial direction AD1. The connecting member through hole 71 is formed in a cylindrical shape when viewed from the first axial direction AD1. The connecting member through hole 71 is arranged coaxially with the first mounting hole 7b of the first protrusion 7 when viewed from the first axial direction AD1. An internal thread portion is formed on the inner circumferential surface of the connecting member through hole 71 to threadably mate with an external thread portion formed on the outer circumferential surface of the fastener F. In the drawings, the external thread portion of the fastener F and the internal thread portion of the connecting member through hole 71 are omitted. By providing the internal thread portion of the first connecting member 70 made of aluminum in the mounting portion 30 included in the housing 10 made of magnesium, the strength and corrosion resistance of the portion connected to the fastener F can be improved.

[0052] The first connecting member end face 72 is a surface of the first connecting member 70 at one end in the first axial direction AD1 that faces in one direction in the first axial direction AD1. In this embodiment, the first connecting member end face 72 is a surface that faces to the right of the human-powered vehicle in the attached and horizontal state. The first connecting member end face 72 is formed in an annular shape when viewed from the first axial direction AD1. The first mounting portion end face 43 of the first mounting portion 40 is located closer to the frame 1 than the first connecting member end face 72 in the mounting portion axial direction.

[0053] "On the frame 1 side of the first connecting member end face 72" means that in the attached state, the first mounting portion 40 is closer to the portion where it is attached to the frame 1 than the first connecting member end face 72. In this embodiment, "on the frame 1 side of the first connecting member end face 72" means that in the attached state, the first mounting portion 40 is closer to the first protrusion 7 than the first connecting member end face 72. Because the first mounting portion end face 43 is located closer to the frame 1 than the first connecting member end face 72 in the first axial direction AD1, the first connecting member end face 72 is disposed at a distance from the first inner surface 7a of the first protrusion 7 in the first axial direction AD1.

[0054] The second connecting member end face 73 is a surface of the first connecting member 70 at the other end in the first axial direction AD1 that faces the other side in the first axial direction AD1. In this embodiment, the second connecting member end face 73 is a surface that faces the left side of the human-powered vehicle when the vehicle is attached and horizontal. The second connecting member end face 73 is formed in an annular shape when viewed from the first axial direction AD1. The second mounting portion end face 44 of the first mounting portion 40 is located on the opposite side of the second connecting member end face 73 from the frame 1 in the mounting portion axial direction.

[0055] The side opposite the frame 1 from the second connecting member end face 73 means that, in the attached state, the first mounting portion 40 is located farther from the portion where it is attached to the frame 1 than the second connecting member end face 73. In this embodiment, the side opposite the frame 1 from the second connecting member end face 73 means that, in the attached state, the first mounting portion 40 is located farther from the first protrusion 7 than the first connecting member end face 72.

[0056] The outer surface 74 is formed to connect the outer edge of the first connecting member end face 72 and the outer edge of the second connecting member end face 73. In this embodiment, since the first connecting member 70 is formed in a cylindrical shape, the outer surface 74 is the outer peripheral surface of the first connecting member 70. The outer surface 74 is formed to correspond to the inner surface 42 of the first mounting portion 40.

[0057] A plurality of second connecting members 80 will be described. FIGS. 4 and 8 illustrate one of the plurality of second connecting members 80. Because the plurality of second connecting members 80 have similar configurations, the second connecting member 80 shown in FIGS. 4 and 8 will be described in this specification, and descriptions of the remaining second connecting members 80 not shown in FIGS. 4 and 8 will be omitted. The second connecting member 80 is formed in a cylindrical shape that allows the adjustment member 90 to be inserted therethrough. The length of the second connecting member 80 along the second axial direction AD2 is shorter than the length of the second mounting portion 50 along the second axial direction AD2. The second connecting member 80 has a connecting member through-hole 81, a first connecting member end face 82, a second connecting member end face 83, and an outer surface 84.

[0058] The connecting member through hole 81 penetrates the second connecting member 80 in the second axial direction AD2. The connecting member through hole 81 is formed in a cylindrical shape when viewed from the second axial direction AD2. The connecting member through hole 81 is arranged coaxially with the second mounting hole 8b of the second protrusion 8 when viewed from the second axial direction AD2. The inner diameter of the connecting member through hole 81 is larger than the inner diameter of the connecting member through hole 71.

[0059] The first connecting member end face 82 is a surface of the second connecting member 80 at one end in the second axial direction AD2 that faces one side in the second axial direction AD2. In this embodiment, the first connecting member end face 82 is a surface that faces leftward of the human-powered vehicle in the mounted state and horizontal state. The first connecting member end face 82 is formed in an annular shape when viewed from the second axial direction AD2. The first mounting portion end face 53 of the second mounting portion 50 is located closer to the frame 1 than the first connecting member end face 82 in the mounting portion axial direction. In this embodiment, "closer to the frame 1 than the first connecting member end face 82" means that the first connecting member end face 82 is closer to the second protrusion 8 than the first connecting member end face 82 in the mounted state. Because the first mounting portion end face 53 is located closer to the frame 1 than the first connecting member end face 82 in the second axial direction AD2, the first connecting member end face 82 is disposed at a distance from the second inner surface 8a of the second protrusion 8 in the second axial direction AD2.

[0060] The second connecting member end face 83 is a surface of the second connecting member 80 at the other end in the second axial direction AD2 that faces the other side in the second axial direction AD2. In this embodiment, the second connecting member end face 83 is a surface that faces the right side of the human-powered vehicle in the attached state and in a horizontal position. The second connecting member end face 83 is formed in an annular shape when viewed from the second axial direction AD2. The second mounting portion end face 54 of the second mounting portion 50 is located on the opposite side of the frame 1 from the second connecting member end face 83 in the mounting portion axial direction. In this embodiment, being on the opposite side of the frame 1 from the second connecting member end face 83 means that in the attached state, the second connecting member end face 83 is located farther from the second protrusion 8 than the first connecting member end face 82.

[0061] The outer surface 84 is formed to connect the outer edge of the first connecting member end face 82 and the outer edge of the second connecting member end face 83 to each other. In this embodiment, since the second connecting member 80 is formed in a cylindrical shape, the outer surface 84 is the outer peripheral surface of the second connecting member 80. The outer surface 84 is formed to correspond to the inner surface 52 of the second mounting portion 50.

[0062] The multiple adjustment members 90 are configured to fill gaps between the multiple second mounting portions 50 and the second protrusions 8. The multiple second mounting portions 50 are provided on the multiple second mounting portions 50. One of the multiple adjustment members 90 is shown in Figure 4. Since the multiple adjustment members 90 are configured similarly to one another, this specification will describe the adjustment member 90 shown in Figure 4, and will omit a description of the remaining adjustment members 90 not shown in Figure 4. The adjustment member 90 is formed in a cylindrical shape when viewed from the second axial direction AD2. An internal thread portion that screws into the external thread portion of the fastener F is formed on the inner circumferential surface of the adjustment member 90. In the drawings, the internal thread portion of the adjustment member 90 is omitted.

[0063] The adjustment member 90 is fixed in the connecting member through hole 81. The adjustment member 90 is fixed in the connecting member through hole 81 by, for example, press fitting. The adjustment member 90 may be fixed in the connecting member through hole 81 by a method other than press fitting. The adjustment member 90 protrudes from the connecting member through hole 81 toward the second protrusion 8 in the second axial direction AD2 and comes into contact with the second inner surface 8a of the second protrusion 8. The adjustment member 90 comes into contact with the second inner surface 8a of the second protrusion 8, thereby filling the gap between the first mounting portion end surface 53 of the second mounting portion 50 and the second inner surface 8a of the second protrusion 8.

[0064] The material of the adjustment member 90 is not particularly limited. The adjustment member 90 may be made of aluminum, for example. By providing the female thread portion of the adjustment member 90 made of aluminum on the mounting portion 30 included in the housing 10 made of magnesium, the strength and corrosion resistance of the portion connected to the fastener F can be improved.

[0065] 2, the mounting portion 30 of the drive unit 9 is attached to the frame 1 by threading fasteners F into the connecting member through holes 71, 81 while the mounting portion 30 is disposed in the internal space of the support portion 5. In this embodiment, the gap between the first mounting portion end surface 53 and the second inner surface 8a of the second protruding portion 8 is filled with the adjustment member 90, thereby increasing the tightening force of the fasteners F in the attached state.

[0066] 3 and 4 will be used to describe the inner surfaces 42, 52 of the mounting portion 30. The inner surfaces 42, 52 include first overlapping portions 42a, 52a that cover at least a portion of the first connecting member end faces 72, 82. In this embodiment, the inner surfaces 42, 52 further include second overlapping portions 42b, 52b that cover at least a portion of the second connecting member end faces 73, 83. The inner surfaces 42, 52 further include at least one inner protrusion 42c, 52c that protrudes from the inner surfaces 42, 52 in the mounting portion radial direction and is disposed between the first connecting member end faces 72, 82 and the second connecting member end faces 73, 83 in the mounting portion axial direction. In this embodiment, the mounting portion radial direction includes a first radial direction RD1 relative to the first central axis CA1 and a second radial direction RD2 relative to the second central axis CA2.

[0067] Figure 3 illustrates the inner surface 42 of one first mounting portion 40. Because the inner surfaces 42 of the multiple first mounting portions 40 are configured similarly to one another, this specification will describe only the inner surface 42 shown in Figure 3, and will omit a description of the inner surfaces 42 of the remaining first mounting portions 40 not shown in Figure 3. The inner surface 42 of the first mounting portion 40 includes a first overlapping portion 42a, a second overlapping portion 42b, and at least one inner protrusion 42c.

[0068] The first overlapping portion 42a is configured to cover the first connecting member end face 72 so that a part or the entirety of the first connecting member end face 72 is not exposed to the outside of the first mounting portion 40 when viewed from the side toward which the first connecting member end face 72 faces. In this embodiment, the first overlapping portion 42a is configured to cover the first connecting member end face 72 when viewed from the right side of the first mounting portion 40 in the mounted and horizontal state. The first overlapping portion 42a is positioned so as to face the left side of the human-powered vehicle in the mounted and horizontal state. The first overlapping portion 42a overlaps with the first connecting member end face 72 when viewed in the first axial direction AD1. The first overlapping portion 42a is located closer to the first protrusion 7 of the frame 1 than the first connecting member end face 72 in the first axial direction AD1. Since the first overlapping portion 42a is positioned closer to the first protrusion 7 than the first connecting member end face 72, a portion or the entire first connecting member end face 72 is not exposed to the right side of the first mounting portion 40 when in the mounted and horizontal state.

[0069] In this embodiment, the first overlapping portion 42a is formed in the same shape as the first connecting member end face 72. By forming the first overlapping portion 42a in the same shape as the first connecting member end face 72, the first overlapping portion 42a covers the entire first connecting member end face 72. Because the first overlapping portion 42a covers the entire first connecting member end face 72, the entire first connecting member end face 72 is not exposed to the right side of the first mounting portion 40 in the mounted and horizontal state. The shape of the first overlapping portion 42a is not limited to this embodiment. For example, the first overlapping portion 42a may have a shape different from that of the first connecting member end face 72.

[0070] A pedaling force is applied to the input rotation shaft AR shown in Figure 5 when a rider steps on a pedal connected to a crank arm. The pedaling force is an example of a human-powered driving force. When a pedaling force is input to the input rotation shaft AR, a load acts on the housing 10. For example, in an attached and horizontal state, a downward load acts on the housing 10.

[0071] In this embodiment, in the mounted and horizontal state, the first connecting member end face 72 is not exposed to the right of the first mounting portion 40. This means that even if a load acts on the housing 10 and causes the housing 10 and the first connecting member 70 to move relative to the frame 1, the load is less likely to act on the first connecting member end face 72 from the first protrusion 7 located on the right side of the first connecting member 70. Because the load is less likely to act on the first connecting member end face 72, when a pedal force is applied to the input rotation shaft AR, movement of the first connecting member 70 along the first axial direction AD1 is suppressed, thereby suppressing stress concentration around the first connecting member 70. Suppressing stress concentration leads to a reduction in the weight of the housing 10. For example, the weight of the housing 10 can be reduced by thinning the first mounting portion 40.

[0072] The first overlapping portion 42a contacts at least a portion of the first connecting member end face 72 in the mounting portion axial direction. In this embodiment, the first overlapping portion 42a is formed in the same shape as the first connecting member end face 72, so the first overlapping portion 42a contacts the entire first connecting member end face 72 in the first axial direction AD1.

[0073] The contact of the first overlapping portion 42a with the first connecting member end face 72 makes it possible to suppress contact between the first connecting member end face 72 and the first inner surface 7a of the first protruding portion 7 in the first axial direction AD1. By suppressing contact between the first connecting member end face 72 and the first inner surface 7a, when a pedal force is input to the input rotation shaft AR, a load is less likely to act on the first connecting member end face 72 from the first protruding portion 7, making it possible to further suppress movement of the first connecting member 70 along the first axial direction AD1. By further suppressing movement of the first connecting member 70 along the first axial direction AD1, it is possible to further suppress stress concentration around the first connecting member 70.

[0074] The second overlapping portion 42b shown in FIG. 3 is configured to cover the second connecting member end face 73 so that a portion or the entirety of the second connecting member end face 73 is not exposed to the outside of the first mounting portion 40 when the first mounting portion 40 is viewed from the side toward which the second connecting member end face 73 faces. In this embodiment, the second overlapping portion 42b is configured to cover the second connecting member end face 73 when the first mounting portion 40 is viewed from the left side in the mounted and horizontal state. The second overlapping portion 42b is positioned to face to the right of the human-powered vehicle in the mounted and horizontal state. The second overlapping portion 42b overlaps with the second connecting member end face 73 when viewed in the first axial direction AD1. The second overlapping portion 42b is located on the opposite side of the frame 1 from the second connecting member end face 73 in the first axial direction AD1. Since the second overlapping portion 42b is positioned on the opposite side of the frame 1 from the second connecting member end face 73, a portion or the entire second connecting member end face 73 is not exposed to the left side of the first mounting portion 40 when in the mounted and horizontal state.

[0075] In this embodiment, the second overlapping portion 42b is formed in the same shape as the second connecting member end face 73. By forming the second overlapping portion 42b in the same shape as the second connecting member end face 73, the second overlapping portion 42b covers the entire second connecting member end face 73. Because the second overlapping portion 42b covers the entire second connecting member end face 73, the entire second connecting member end face 73 is not exposed to the left side of the first mounting portion 40 in the mounted and horizontal state. The shape of the second overlapping portion 42b is not limited to this embodiment. For example, the second overlapping portion 42b may have a shape different from that of the second connecting member end face 73.

[0076] In the attached and horizontal state, the second connecting member end face 73 is not exposed to the left side of the first mounting portion 40, which makes it difficult for a load to act from the left side on the second connecting member end face 73. Since a load is unlikely to act from the left side on the second connecting member end face 73, movement of the first connecting member 70 can be suppressed, which further suppresses stress concentration around the first connecting member 70.

[0077] The second overlapping portion 42b contacts at least a portion of the second connecting member end face 73 in the mounting portion axial direction. In the present embodiment, the second overlapping portion 42b is formed in the same shape as the second connecting member end face 73, and therefore the second overlapping portion 42b contacts the entire second connecting member end face 73 in the first axial direction AD1.

[0078] The second overlapping portion 42b comes into contact with the second connecting member end face 73, making it even more difficult for a load to act from the left side on the second connecting member end face 73. Since it is even more difficult for a load to act from the left side on the second connecting member end face 73, stress concentration around the first connecting member 70 can be further suppressed.

[0079] At least one inner protrusion 42c is formed in a middle portion of the inner surface 42 in the first axial direction AD1. At least one inner protrusion 42c is formed in a middle portion of the inner surface 42 in the first axial direction AD1, over at least a portion of the circumferential direction about the first central axis CA1. In the present embodiment, at least one inner protrusion 42c is formed in a middle portion of the inner surface 42 in the first axial direction AD1, over the entire circumferential direction. The at least one inner protrusion 42c includes one inner protrusion 42c. The number of inner protrusions 42c is not limited to this embodiment. The at least one inner protrusion 42c has an inner protrusion end face 42d, a radial end 42e, and an inclined surface 42f.

[0080] The inner protrusion end face 42d is a surface facing the first axial direction AD1. In this embodiment, the inner protrusion end face 42d is a surface facing leftward of the human-powered vehicle in the attached state and in the horizontal position. The radial end portion 42e is an inner end portion of at least one inner protrusion 42c in the first radial direction RD1. The radial end portion 42e is positioned more inward in the first radial direction RD1 than the inner protrusion end face 42d and the inclined surface 42f. The radial end portion 42e is formed in a linear shape extending along the first axial direction AD1 in a rear cross-sectional view in the attached state and in the horizontal position. The radial end portion 42e is positioned between the inner protrusion end face 42d and the inclined surface 42f in the first axial direction AD1.

[0081] The inclined surface 42f is a surface that is inclined with respect to the first axial direction AD1 and the first radial direction RD1. The inclined surface 42f extends outward in the first radial direction RD1 as it moves away from the radial end portion 42e in the first axial direction AD1.

[0082] FIG. 4 illustrates the inner surface 52 of one second mounting portion 50. Because the inner surfaces 52 of the multiple second mounting portions 50 are configured similarly to one another, this specification will describe only the inner surface 52 shown in FIG. 4, and will omit descriptions of the inner surfaces 52 of the remaining second mounting portions 50 not shown in FIG. 4. The inner surface 52 of the second mounting portion 50 includes a first overlapping portion 52a, a second overlapping portion 52b, and at least one inward protrusion 52c. The first overlapping portion 52a is positioned to face the right of the human-powered vehicle in the mounted and horizontal state. The first overlapping portion 52a is configured similarly to the first overlapping portion 42a of the first mounting portion 40, except for the inner and outer diameters. The second overlapping portion 52b is positioned to face the left of the human-powered vehicle in the mounted and horizontal state. The second overlapping portion 52b is configured similarly to the second overlapping portion 42b, except for the inner and outer diameters. The first overlapping portion 52a and the second overlapping portion 52b suppress movement of the second connecting member 80 along the first axial direction AD1 in the second axial direction AD2 when a pedal force is input to the input rotation shaft AR, thereby suppressing stress concentration around the second connecting member 80.

[0083] At least one inner protrusion 52c is formed in a middle portion of the inner surface 52 in the second axial direction AD2. At least one inner protrusion 52c is formed in a middle portion of the inner surface 52 in the second axial direction AD2, over at least a portion of the circumferential direction about the second central axis CA2. In this embodiment, at least one inner protrusion 52c is formed in a middle portion of the inner surface 52 in the second axial direction AD2, over the entire circumferential direction. The at least one inner protrusion 52c includes one inner protrusion 52c. The number of inner protrusions 52c is not limited to this embodiment. The at least one inner protrusion 52c has a radial end 52d and two inclined surfaces 52e.

[0084] The radial end portion 52d is an inner end portion of at least one inner protrusion portion 52c in the first radial direction RD1. The radial end portion 52d is disposed more inward in the second radial direction RD2 than the two inclined surfaces 52e. In a rear cross-sectional view in the mounted and horizontal state, the radial end portion 52d is formed in a linear shape extending along the second axial direction AD2. The two inclined surfaces 52e are surfaces inclined with respect to the second axial direction AD2 and the second radial direction RD2. One of the two inclined surfaces 52e is continuous with the radial end portion 52d on one side in the second axial direction AD2. The other of the two inclined surfaces 52e is continuous with the radial end portion 52d on the other side in the second axial direction AD2. In the second axial direction AD2, the two inclined surfaces 52e extend outward in the second radial direction RD2 as they move away from the radial end portion 52d.

[0085] The outer surfaces 74, 84 of the connecting member 60 will be described using Figures 3, 4, 7, and 8. The outer surfaces 74, 84 include at least one outer protrusion 75, 85 that protrudes from the outer surfaces 74, 84 in a radial direction of the attachment portion relative to the central axis of the attachment portion through holes 41, 51. In this embodiment, the at least one outer protrusion 75, 85 includes multiple outer protrusions. The multiple outer protrusions include a first outer protrusion 76, 86 and a second outer protrusion 77, 87. The multiple outer protrusions are arranged at intervals from each other in the axial direction of the attachment portion. The number of the at least one outer protrusion 75, 85 is not limited to this embodiment.

[0086] 3 and 7 illustrate the outer surface 74 of one first connecting member 70. Because the outer surfaces 74 of the multiple first connecting members 70 are configured similarly to one another, this specification will describe only the outer surface 74 of one first connecting member 70 shown in FIGS. 3 and 7, and will omit a description of the outer surfaces 74 of the remaining first connecting members 70 not shown in FIGS. 3 and 7. The outer surface 74 of the first connecting member 70 includes at least one outer protrusion 75. The at least one outer protrusion 75 includes a first outer protrusion 76 and a second outer protrusion 77.

[0087] The first outer protrusion 76 is located closer to the first protrusion 7 of the frame 1 than the second outer protrusion 77 in the first axial direction AD1. In this embodiment, the first outer protrusion 76 is located to the right of the second outer protrusion 77 in the mounted and horizontal state. The first outer protrusion 76 is formed on at least a portion of the circumferential direction about the first central axis CA1, closer to the first protrusion 7 than the second outer protrusion 77. In this embodiment, the first outer protrusion 76 is formed on the entire circumferential direction, closer to the first protrusion 7 than the second outer protrusion 77. The first outer protrusion 76 has a radial end 76a in the mounting portion radial direction, and an inclined surface 76b that approaches the radial end 76a in the mounting portion radial direction as it approaches the radial end 76a in the mounting portion axial direction.

[0088] The radial end portion 76a is an outer end portion of the first outer protrusion portion 76 in the first radial direction RD1. The radial end portion 76a is disposed outward of the inclined surface 76b in the first radial direction RD1. The radial end portion 76a is formed in an arc shape in a rear cross-sectional view in the mounted state and horizontal state. The radial end portion 76a is disposed between the first connecting member end face 72 and the inclined surface 76b in the mounting portion axial direction. The radial end portion 76a is adjacent to the first connecting member end face 72 in the first axial direction AD1. The inclined surface 76b is a surface inclined with respect to the first axial direction AD1 and the first radial direction RD1. The inclined surface 76b is adjacent to the radial end portion 76a in the mounting portion axial direction. The inclined surface 76b is formed to correspond to the inclined surface 42f so that the orientation of the inclined surface 76b is relatively close to the orientation of the inclined surface 42f of the first mounting portion 40.

[0089] For example, the inclined surface 76b is formed so that the difference between the inclination angle with respect to the first axis direction AD1 and the inclination angle of the inclined surface 42f with respect to the first axis direction AD1 is equal to or less than a predetermined threshold. The magnitude of the predetermined threshold is not particularly limited. The predetermined threshold may be selected, for example, from a range of 0 to 5 degrees.

[0090] The second outer protrusion 77 is formed over the entire circumferential direction about the first central axis CA1 at a position spaced apart in the first axial direction AD1 from the first outer protrusion 76. The second outer protrusion 77 has a radial end portion 77a in the first radial direction RD1 and an outer protrusion end face 77b in the first axial direction AD1.

[0091] The radial end portion 77a is the outer end portion of the second outer protrusion portion 77 in the first radial direction RD1. The radial end portion 77a is positioned further outward in the first radial direction RD1 than the outer protrusion portion end face 77b. The radial end portion 77a is formed in a linear shape along the first axial direction AD1 in a rear cross-sectional view in the attached state and in a horizontal position. The radial end portion 77a is adjacent to the second connecting member end face 73 in the first axial direction AD1. The outer protrusion portion end face 77b is a surface facing the first axial direction AD1. In this embodiment, the outer protrusion portion end face 77b is a surface facing toward the right of the human-powered vehicle in the attached state and in a horizontal position. The outer protrusion portion end face 77b is formed in an annular shape when viewed in the first axial direction AD1.

[0092] At least one outer protrusion 75 and at least one inner protrusion 42c are adjacent to each other in the attachment portion axial direction. In this embodiment, the inclined surface 76b of the first outer protrusion 76 and the inclined surface 42f of the inner protrusion 42c are adjacent to each other in the first axial direction AD1. The outer protrusion end surface 77b of the second outer protrusion 77 and the inner protrusion end surface 42d of the inner protrusion 42c are adjacent to each other in the first axial direction AD1. By having at least one outer protrusion 75 and at least one inner protrusion 42c adjacent to each other in the first axial direction AD1, movement of the first connecting member 70 along the first axial direction AD1 can be suppressed, thereby further suppressing stress concentration around the first connecting member 70.

[0093] 4 and 8 illustrate the outer surface 84 of one second connecting member 80. Because the outer surfaces 84 of the multiple second connecting members 80 are configured similarly to one another, this specification will describe the outer surface 84 of one second connecting member 80 shown in FIGS. 4 and 8, and will omit a description of the outer surfaces 84 of the remaining second connecting members 80 not shown in FIGS. 4 and 8. The outer surface 84 of the second connecting member 80 includes at least one outer protrusion 85. The at least one outer protrusion 85 includes a first outer protrusion 86 and a second outer protrusion 87.

[0094] The first outer protrusion 86 is located closer to the second protrusion 8 of the frame 1 than the second outer protrusion 87 in the second axial direction AD2. In this embodiment, the first outer protrusion 86 is located to the left of the second outer protrusion 87 in the mounted and horizontal state. The first outer protrusion 86 is formed on at least a portion of the circumferential direction about the second central axis CA2, on the second protrusion 8 side of the second outer protrusion 87. In this embodiment, the first outer protrusion 86 is formed on the entire circumferential direction, on the second protrusion 8 side of the second outer protrusion 87. The first outer protrusion 86 has a radial end 86a and an inclined surface 86b.

[0095] The radial end 86a is an outer end of the first outer protrusion 86 in the second radial direction RD2. The radial end 86a is disposed further outward in the second radial direction RD2 than the inclined surface 86b. In a rear cross-sectional view in the mounted and horizontal state, the radial end 86a is formed in a linear shape along the second axial direction AD2. The radial end 86a is adjacent to the first connecting member end face 82 in the second axial direction AD2. The inclined surface 86b is a surface inclined with respect to the second axial direction AD2 and the second radial direction RD2. The inclined surface 86b is adjacent to the radial end 86a and one of the two inclined surfaces 52e of the inner protrusion 52c in the second axial direction AD2. The inclined surface 86b is formed to correspond to one of the two inclined surfaces 52e so that the orientation of the inclined surface 86b is relatively close to one of the two inclined surfaces 52e.

[0096] The second outer protrusion 87 is formed on at least a portion of the circumferential direction about the second central axis CA2 at a position spaced apart from the first outer protrusion 86 in the second axial direction AD2. In the present embodiment, the second outer protrusion 87 is formed on the entire circumferential direction at a position spaced apart from the first outer protrusion 86 in the second axial direction AD2. The second outer protrusion 87 has a radial end 87a and an inclined surface 87b.

[0097] The radial end 87a is an outer end of the second outer protrusion 87 in the second radial direction RD2. The radial end 87a is disposed more inward in the second radial direction RD2 than the inclined surface 87b. In a rear cross-sectional view in the attached and horizontal state, the radial end 87a is formed in a linear shape along the second axial direction AD2. The radial end 87a is adjacent to the second connecting member end face 83 in the second axial direction AD2. The inclined surface 87b is adjacent to the radial end 87a and the other of the two inclined surfaces 52e of the inner protrusion 52c in the second axial direction AD2. The inclined surface 87b is formed to correspond to the other of the two inclined surfaces 52e so that the orientation of the inclined surface 87b is relatively close to the other of the two inclined surfaces 52e.

[0098] At least one outer protrusion 85 and at least one inner protrusion 52c are adjacent to each other in the attachment portion axial direction. In this embodiment, the inclined surface 86b of the first outer protrusion 86 and one of the two inclined surfaces 52e of the inner protrusion 52c are adjacent to each other in the second axial direction AD2. The inclined surface 87b of the second outer protrusion 87 and the other of the two inclined surfaces 52e are adjacent to each other in the second axial direction AD2. By having at least one outer protrusion 85 and at least one inner protrusion 52c adjacent to each other in the second axial direction AD2, movement of the second connecting member 80 along the second axial direction AD2 can be suppressed, thereby further suppressing stress concentration around the second connecting member 80.

[0099] The shape of the at least one outer protrusion 75, 85 is not limited to that of the present embodiment. By changing the shape of the at least one outer protrusion 75, 85 to a shape different from that of the present embodiment, the magnitude of stress generated around the at least one outer protrusion 75, 85 on the inner surface 42, 52 can be adjusted. For example, by changing the shape of the first outer protrusion 76 shown in FIG. 3 to a shape that does not have the inclined surface 76b, the magnitude of stress generated around the first outer protrusion 76 on the inner surface 42 can be adjusted. The width of the at least one outer protrusion 75, 85 along the attachment portion axial direction is not limited to that of the present embodiment. By changing the width of the at least one outer protrusion 75, 85 along the attachment portion axial direction to a width different from that of the present embodiment, the magnitude of stress generated around the at least one outer protrusion 75, 85 on the inner surface 42, 52 can be adjusted.

[0100] Another example of the drive unit 9 will be described with reference to FIGS. 9 to 12. FIGS. 9 and 11 are cross-sectional views of the first mounting portion 40 in the mounted, horizontal position, as viewed from the rear of the human-powered vehicle. Because the mounting portion through-holes 41, 51 and the connecting member 60 are cylindrical when viewed in the mounting portion axial direction, the drive unit 9 may have a restricting portion 95 that restricts rotation in the circumferential direction about the central axis of the mounting portion through-hole. For example, the restricting portion 95 may have a first engaging portion 96 formed on the outer circumferential surface of the connecting member 60 and a second engaging portion 97 formed on the inner surfaces 42, 52 and engaging with the first engaging portion 96 in the circumferential direction. The outer circumferential surface of the connecting member 60 includes at least one of the outer surfaces 74 of the multiple first connecting members 70 and the outer surfaces 84 of the multiple second connecting members 80.

[0101] As shown in Fig. 9, for example, the first engagement portion 96 and the second engagement portion 97 may include knurling 96a, 97a. As an example of the knurling 96a, Figs. 9 and 10 show the knurling 96a formed on the outer surface 74 of the first connecting member 70. As shown in Fig. 10, the knurling 96a is formed on the outer peripheral surface of the second outer protrusion 77. The knurling 97a of the second engagement portion 97 shown in Fig. 9 is formed on the inner surface 42 of the first mounting portion 40 so as to mesh with the knurling 96a of the first engagement portion 96.

[0102] The configuration of the knurling 96a, 97a is not limited to the configuration shown in Figures 9 and 10. For example, the knurling 96a may be formed on the outer surface 84 of the second connecting member 80. For example, the knurling 97a may be formed on the inner surface 52 of the second mounting portion 50.

[0103] 11 and 12, for example, the first engagement portion 96 may include at least one first flat portion 96b formed on at least a portion of the outer circumferential surface of the connecting member 60. As an example of the at least one first flat portion 96b, FIGS. 11 and 12 show at least one first flat portion 96b formed on the outer surface 74 of one first connecting member 70. As shown in FIG. 12, the at least one first flat portion 96b is formed on the outer circumferential surface of the second outer protrusion 77. The at least one first flat portion 96b includes one first flat portion 96b. When the at least one first flat portion 96b includes one first flat portion 96b, a portion of the first connecting member 70 is formed in a D-cut shape.

[0104] For example, the second engagement portion 97 may include at least one second flat surface 97b formed on at least a portion of the inner surface 42, 52. As shown in FIG. 11 , the at least one second flat surface 97b is formed, for example, on the inner surface 42 of the first mounting portion 40. The at least one second flat surface 97b contacts the at least one first flat surface 96b in the circumferential direction about the first central axis CA1. The at least one second flat surface 97b includes, for example, one second flat surface 97b. When the at least one second flat surface 97b includes one second flat surface 97b, the inner surface 42 is formed in a D-cut shape.

[0105] The configuration of the at least one first flat surface portion 96b is not limited to the configuration shown in Figures 11 and 12. For example, the at least one first flat surface portion 96b may be formed in a plurality of portions on the outer surface 74. The at least one first flat surface portion 96b may be formed on the outer surface 84 of the second connecting member 80.

[0106] The configuration of the at least one second flat surface portion 97b is not limited to the configuration shown in Fig. 11. For example, the at least one second flat surface portion 97b may be formed in a plurality of portions on the inner surface 42. The at least one second flat surface portion 97b may be formed on the inner surface 52 of the second mounting portion 50.

[0107] By providing the restricting portion 95 to the drive unit 9, relative rotation of the connecting member 60 with respect to the mounting portion 30 can be restricted when the male thread portion of the fastener F is screwed into the female thread portion of the connecting member 60. By restricting relative rotation of the connecting member 60 with respect to the mounting portion 30, the drive unit 9 can be easily attached to the frame 1.

[0108] The configuration of the restricting portion 95 is not limited to the configuration shown in Figures 9 to 12. The restricting portion 95 may restrict rotation in the circumferential direction about the central axis of the attachment portion through hole, for example, by the outer peripheral surface of the connecting member 60 that is elliptically formed when viewed in the attachment portion axial direction, and the inner surfaces 42, 52 that are elliptically formed when viewed in the attachment portion axial direction.

[0109] (Variation) The description of each embodiment is merely an example of a form that the present invention can take, and is not intended to limit the present invention. For example, the present invention can take the form of a modified example of each embodiment shown below, or a combination of at least two modified examples that are not mutually contradictory.

[0110] For example, the configuration of the drive unit 9 in each embodiment is an example, and the drive unit 9 may include various devices not shown in each embodiment, or may be configured not to include some of the various devices shown in each embodiment.

[0111] For example, the first overlapping portions 42a, 52a may not contact the first connecting member end faces 72, 82 in the mounting portion axial direction. The second overlapping portions 42b, 52b may not contact the second connecting member end faces 73, 83 in the mounting portion axial direction. For example, the first connecting member end faces 72, 82 may be partially exposed from the mounting portion 30. For example, the second connecting member end faces 73, 83 may be partially exposed from the mounting portion 30.

[0112] 13 and 14 show an example of a first connecting member end face 72 that is partially exposed from the mounting portion 30. The first connecting member end face 72 shown in FIGS. 13 and 14 has an exposed portion 72a formed to be exposed from the first mounting portion 40. The exposed portion 72a is formed to partially protrude in the first axial direction AD1. The exposed portion 72a is disposed so as to be flush with the first mounting portion end face 43. The exposed portion 72a can suppress relative rotation of the connecting member 60 with respect to the mounting portion 30.

[0113] For example, the outer surfaces 74, 84 of the coupling member 60 may not include at least one outward protrusion 75, 85. The inner surfaces 42, 52 of the mounting portion 30 may not include at least one inward protrusion 42c, 52c.

[0114] The phrase "at least one" as used herein means "one or more" of the desired options. As an example, the phrase "at least one" as used herein means "only one option" or "both of two options" if the number of options is two. As another example, the phrase "at least one" as used herein means "only one option" or "any combination of two or more options" if the number of options is three or more. [Explanation of symbols]

[0115] 1...frame, 9...drive unit, 30...mounting portion, 60...connecting member, 41, 51...mounting portion through-hole, 42, 52...inner surface, 42a, 52a...first overlapping portion, 42b, 52b...second overlapping portion, 42c, 52c...at least one inner protrusion, 43, 53...first mounting portion end surface, 44, 54...second mounting portion end surface, 71, 81...connecting member through-hole, 72, 82...first connecting member end surface, 73, 83...second connecting member end surface, 74, 84...outer surface, 75, 85... At least one outer protrusion, 76a, 77a, 86a, 87a...radial end portion, 76b, 86b, 87b...inclined surface, 95...regulating portion, 96...first engaging portion, 97...second engaging portion, 96a, 97a...knurling, 96b...at least one first flat portion, 97b...at least one second flat portion, AD1...first axial direction, AD2...second axial direction, CA1...first central axis, CA2...second central axis, F...fastener, RD1...first radial direction, RD2...second radial direction

Claims

1. A drive unit for a human-powered vehicle, a housing including a mounting portion that can be attached to a frame of the human-powered vehicle by a fastener; a connecting member provided on the attachment portion and configured to connect to the fastener; the mounting portion has an inner surface that defines a mounting portion through hole that penetrates the mounting portion and in which the connecting member is disposed in an internal space, and a first mounting portion end surface that faces the frame in a mounting portion axial direction relative to a central axis of the mounting portion through hole, the connecting member has a connecting member through-hole that penetrates the connecting member and through which the fastener can be inserted, and a first connecting member end surface that is formed on the frame side in the attachment portion axial direction in an attachment state in which the attachment portion is attached to the frame, The drive unit, wherein the first mounting portion end surface is located closer to the frame than the first connecting member end surface in the mounting portion axial direction.

2. The drive unit according to claim 1 , wherein the inner surface of the mounting portion includes a first overlapping portion that covers at least a portion of the first connecting member end face.

3. The drive unit according to claim 2 , wherein the first overlapping portion covers the entire end surface of the first connecting member.

4. The drive unit according to claim 2 , wherein the first overlapping portion contacts at least a portion of the end surface of the first connecting member in the attachment portion axial direction.

5. the connecting member further includes a second connecting member end surface opposite to the first connecting member end surface in the mounting portion axial direction, and an outer surface connecting the first connecting member end surface and the second connecting member end surface, the outer surface includes at least one outer protrusion protruding from the outer surface in a radial direction of the attachment portion relative to a central axis of the attachment portion through hole, the inner surface includes at least one inner protrusion that protrudes from the inner surface in the attachment portion radial direction and is disposed between the first connecting member end surface and the second connecting member end surface in the attachment portion axial direction, The drive unit according to claim 1 , wherein the at least one outer protrusion and the at least one inner protrusion are adjacent to each other in the axial direction of the mounting portion.

6. the at least one outer protrusion includes a plurality of outer protrusions; The drive unit according to claim 5 , wherein the plurality of outer protrusions are arranged at intervals from one another in the axial direction of the mounting portion.

7. The drive unit of claim 5, wherein the at least one outer protrusion has a radial end portion relative to the mounting portion radial direction and an inclined surface that approaches the radial end portion in the mounting portion radial direction as it extends toward the radial end portion in the mounting portion axial direction.

8. the radial end portion is disposed between the first connecting member end surface and the inclined surface in the attachment portion axial direction, The drive unit according to claim 7 , wherein the inclined surface is adjacent to the radial end portion in the axial direction of the mounting portion.

9. the mounting portion further has a second mounting portion end surface opposite to the first mounting portion end surface in the mounting portion axial direction, the connecting member further has a second connecting member end surface opposite to the first connecting member end surface in the mounting portion axial direction, The drive unit according to claim 1 , wherein the second mounting portion end surface is located on the opposite side of the second connecting member end surface from the frame in the mounting portion axial direction.

10. The drive unit according to claim 9 , wherein the inner surface of the mounting portion includes a second overlapping portion that covers at least a portion of the second connecting member end face.

11. The drive unit according to claim 10 , wherein the second overlapping portion covers the entire end surface of the second connecting member.

12. The drive unit according to claim 10 , wherein the second overlapping portion contacts at least a portion of the end surface of the second connecting member in the attachment portion axial direction.

13. The inner surface is formed in a cylindrical shape when viewed in the axial direction of the mounting portion, The connecting member is formed in a cylindrical shape having a central axis, The drive unit according to claim 1 , further comprising a restricting portion that restricts rotation in a circumferential direction about a central axis of the mounting portion through hole.

14. The drive unit according to claim 13, wherein the regulating portion has a first engaging portion formed on an outer peripheral surface of the connecting member, and a second engaging portion formed on the inner surface and engaging with the first engaging portion in the circumferential direction.

15. The drive unit according to claim 14 , wherein the first engagement portion and the second engagement portion include knurling.

16. the first engagement portion includes at least one first flat portion formed on at least a part of an outer circumferential surface of the connecting member, The drive unit according to claim 14 , wherein the second engagement portion includes at least one second flat portion formed on at least a portion of the inner surface.

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