Motor unit and electric vehicle

Abstract

To provide a motor unit having high assembling workability.SOLUTION: The motor unit 100 used for an electric vehicle includes a substrate 150 and four rotation mechanisms (for example, a motor 110, a crank rotation mechanism 120, a speed reduction mechanism 130, and a crank rotation sensor unit 140) disposed such that each rotation axis intersects a main surface of the substrate 150. The substrate 150 has four recessed portions (for example, a first recessed portion 151, a second recessed portion 152, a third recessed portion 153, and a fourth recessed portion 154) provided in the outer peripheral portion in a plan view in one to-one correspondence with the four rotation mechanisms, and at least a part of the corresponding rotation mechanism is disposed in each of the four recessed portions.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a motor unit and an electric vehicle. [Background technology]

[0002] Patent Document 1 discloses a component for a human-powered vehicle that assists the propulsion of the human-powered vehicle. The component for a human-powered vehicle includes a first circuit board having a control unit that controls the electric motor, a second circuit board having a magnetostrictive torque sensor and the like, and a third circuit board having a receiving unit that receives a wireless signal from the torque sensor. The third circuit board is formed in a ring shape so as to surround the periphery of the crankshaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7136564 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional components for human-powered vehicles described above have a problem in that the crankshaft needs to be passed through the ring-shaped third circuit board, making assembly workability difficult.

[0005] Therefore, an object of the present invention is to provide a motor unit that can be assembled easily and an electric vehicle equipped with the motor unit. [Means for solving the problem]

[0006] A motor unit according to one embodiment of the present invention is a motor unit used in an electric vehicle, and comprises a substrate and four rotation mechanisms arranged so that each rotation axis intersects with the main surface of the substrate, and the substrate has four recesses on its outer periphery in a planar view, which correspond one-to-one to the four rotation mechanisms, and at least a portion of the corresponding rotation mechanism is arranged in each of the four recesses.

[0007] An electric vehicle according to one aspect of the present invention comprises a motor unit according to the above aspect, a wheel to which the rotational force of at least one of the four rotation mechanisms is transmitted, and a frame supporting the motor unit and the wheel. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a motor unit that is easy to assemble and an electric vehicle equipped with the motor unit. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view of an electric bicycle equipped with a motor unit according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the motor unit according to the embodiment. [Figure 3] FIG. 3 is a plan view showing the positional relationship between a substrate and a rotation mechanism included in the motor unit according to the embodiment. [Figure 4] FIG. 4 is a plan view of a substrate provided in the motor unit according to the embodiment. [Figure 5] FIG. 5 is a plan view for explaining a method of cutting out the substrate shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] A motor unit and an electric vehicle according to embodiments of the present invention will be described in detail below with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present invention. Therefore, the numerical values, shapes, materials, components, component arrangements and connection forms, steps, and step sequences shown in the following embodiments are merely examples and are not intended to limit the present invention. Therefore, among the components in the following embodiments, components not recited in independent claims will be described as optional components.

[0011] Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Therefore, for example, the scales of the figures do not necessarily match. Furthermore, in each figure, substantially the same components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0012] Furthermore, in this specification, terms indicating the relationship between elements, such as parallel or perpendicular, terms indicating the shape of elements, such as rectangular or circular, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0013] Furthermore, in this specification, ordinal numbers such as "first" and "second" do not refer to the number or order of components unless otherwise specified, but are used for the purpose of avoiding confusion and distinguishing between components of the same type.

[0014] In addition, in this specification, "forward" refers to the direction in which an electric vehicle travels during normal driving, and "rearward" refers to the opposite direction. Specifically, in the case of an electric bicycle, the direction in which the handlebars are positioned relative to the saddle is "forward." "Forward-backward direction" refers to the direction from rear to forward, and the opposite direction, among multiple horizontal directions (any direction parallel to the ground). "Right-left direction" refers to the direction perpendicular to the forward-backward direction, and when facing forward, the left side is the "left" and the right side is the "right."

[0015] (Embodiment) [composition] First, the configuration of an electric bicycle according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a side view showing the configuration of an electric bicycle 1 equipped with a motor unit 100 according to this embodiment.

[0016] The electric bicycle 1 shown in Fig. 1 is an example of an electric vehicle and is a bicycle with an electric assist function. The electric assist function is a function that assists the forward movement of the electric bicycle 1 based on the force applied to the pedals 17 by the user riding the electric bicycle 1, and is executed in a so-called assist mode.

[0017] As shown in FIG. 1, the electric bicycle 1 includes a body 10, a battery 20, and a motor unit 100.

[0018] The body 10 is the main body of the electric bicycle 1. The body 10 includes a frame 11, a front wheel 12, a rear wheel 13, a handlebar 14, a saddle 15, cranks 16, pedals 17, a chain 18, a front sprocket 19a, and a rear sprocket 19b.

[0019] The frame 11 is the skeleton of the electric bicycle 1. The frame 11 is made of, for example, metal, carbon, or synthetic resin. The frame 11 is formed by combining multiple tubular members such as a head tube, a down tube, a seat tube, a chainstay, and a front fork. The frame 11 may have a shock-absorbing member such as a suspension. The frame 11 supports a front wheel 12, a rear wheel 13, a handlebar 14, a saddle 15, a crank 16, a chain 18, a front sprocket 19a, and a rear sprocket 19b.

[0020] The front wheels 12 have tires for the vehicle body 10 to travel on. The front wheels 12 are the front wheels of two wheels aligned in the front-to-rear direction. The front wheels 12 are supported by the frame 11 so that they can rotate around an axis extending in the left-to-right direction. The front wheels 12 may receive power from the motor unit 100, i.e., the rotational force of the motor 110 (see FIG. 2).

[0021] The rear wheel 13 has a tire for driving the vehicle body 10. The rear wheel 13 is the rear wheel of two wheels aligned in the front-to-rear direction. The rear wheel 13 is supported by the frame 11 so that it can rotate about an axis extending in the left-to-right direction. In this embodiment, the rear wheel 13 receives power from the motor unit 100, i.e., the rotational force of the motor 110. The rear wheel 13 is connected to a front sprocket 19a via a chain 18 and a rear sprocket 19b.

[0022] The handlebars 14 are operated by a user riding the electric bicycle 1 to change the steering angle of the electric bicycle 1. The handlebars 14 are rotatably supported by the frame 11. A pair of grips and a pair of brake levers are provided at both ends of the handlebars 14. The pair of grips are held by the user's hands when the user is riding the electric bicycle 1 in an appropriate posture. The pair of grips are also held by the hands when pushing or supporting the electric bicycle 1 and walking, and receive forward pushing force, etc. The pair of brake levers apply mechanical braking force to the front wheel 12 and rear wheel 13, for example, by operating a brake device.

[0023] The saddle 15 is a portion on which a user sits and is attached to the frame 11 so that the height of the saddle 15 can be adjusted.

[0024] The crank 16 has a crankshaft 16a and a pair of crank arms 16b. The crank arms 16b are provided on both the left and right sides of the motor unit 100, and are fixed to both ends of the crankshaft 16a, which extends in the left-right direction. One end of the crank arm 16b is rotatably fixed to the crankshaft 16a, and the pedal 17 is rotatably fixed to the other end of the crank arm 16b.

[0025] The pedals 17 receive a pedaling force from the user riding the electric bicycle 1. The pedals 17 are attached to the longitudinal ends of each crank arm 16b on the opposite side from the crank shaft 16a. The pedals 17 are attached to the crank arms 16b so as to be rotatable relative to the crank arms 16b. The rotation axis of the pedals 17 is approximately parallel to the rotation axis of the crank shaft 16a of the crank 16.

[0026] When a pedaling force is applied to the pedal 17, the crank arm 16b rotates around the crank shaft 16a, and the manual driving force resulting from this rotation is transmitted to the rear wheel 13 via the front sprocket 19a, the chain 18, and the rear sprocket 19b. When the electric bicycle 1 operates in the assist mode, the manual driving force based on the pedaling force and the auxiliary driving force of the motor 110 added to the manual driving force are transmitted to the rear wheel 13.

[0027] The chain 18 is an example of a power transmission member that transmits the rotational force of the front sprocket 19a to the rear sprocket 19b. The chain 18 connects the front sprocket 19a and the rear sprocket 19b. Note that instead of the chain 18, a belt, a shaft, a wire, a gear, or the like may be used as the power transmission member. For example, when the power transmission member is a belt, compared to when the power transmission member is a chain 18, effects such as quieter operation, improved durability, and reduced maintenance frequency can be expected.

[0028] The front sprocket 19a is attached to the crankshaft 16a of the crank arm 16b. When the user steps on the pedal 17, the front sprocket 19a rotates via the crank arm 16b and the crankshaft 16a. The rotational force of the front sprocket 19a is transmitted to the rear sprocket 19b attached to the rear wheel 13 via the chain 18. This causes the rear sprocket 19b to rotate, and the rear wheel 13 to rotate. The front sprocket 19a is also called the drive sprocket, and the rear sprocket 19b is also called the driven sprocket.

[0029] The battery 20 is a storage battery that stores power for driving the motor 110 of the motor unit 100. The battery 20 is, for example, a secondary battery, but may also be another charge / discharge element such as a capacitor. The battery 20 is electrically connected to the motor 110 and supplies power to the motor 110.

[0030] The battery 20 is removably fixed to the frame 11. There are no particular limitations on the mounting position of the battery 20. Furthermore, if the electric bicycle 1 is equipped with lighting devices such as a headlight and a taillight, and electronic devices such as a display unit and an operation unit, the battery 20 can also supply power to these lighting devices and electronic devices.

[0031] The motor unit 100 is an example of a motor unit used in an electric vehicle. As shown in Fig. 2, the motor unit 100 includes a motor (first rotation mechanism) 110, a crank rotation mechanism (second rotation mechanism) 120, a speed reduction mechanism (third rotation mechanism) 130, a crank rotation sensor unit (fourth rotation mechanism) 140, a substrate 150, a case 160, and a control circuit 170. Fig. 2 is a cross-sectional view of the motor unit 100 according to this embodiment. Fig. 2 shows a cross section including the center of the crankshaft 16a and the center of the motor shaft 113 of the motor 110.

[0032] The motor 110 is an example of a first rotation mechanism having a motor shaft 113. The motor 110 is an electric motor that receives power from the battery 20 and is driven based on the control of a control circuit provided on the substrate 150. As shown in FIG. 2 , the motor 110 has a stator 111, a rotor 112, and a motor shaft (output shaft) 113.

[0033] The motor 110 is supported by a case 160 so that the rotor 112 and motor shaft 113 can rotate via bearings. Specifically, the stator 111 receives power from the battery 20 and rotates the rotor 112. The motor shaft 113 rotates in accordance with the rotation of the rotor 112. A toothed portion 114 is provided on the tip side of the motor shaft 113, and is engaged with a large diameter gear 131 of the reduction mechanism 130. The rotation of the toothed portion 114 causes the large diameter gear 131 to rotate.

[0034] The crank rotation mechanism 120 is an example of a second rotation mechanism having a crankshaft 16a. The crankshaft 16a is provided to pass through the case 160. The crankshaft 16a is rotatably supported by a bearing. The crank rotation mechanism 120 includes a human power transmission body 121, an intermediate cylinder 122, and an interlocking body 123. The human power transmission body 121, the intermediate cylinder 122, and the interlocking body 123 are all cylindrical members, and the crankshaft 16a is inserted into the cylinders.

[0035] The power transmitting body 121 is fitted into a serration portion 124 provided on the crankshaft 16a, and is provided to rotate integrally with the crankshaft 16a. The intermediate cylinder 122 is provided rotatably relative to the crankshaft 16a, and is provided to rotate integrally with each of the power transmitting body 121 and the interlocking body 123. A front sprocket 19a (not shown in FIG. 2) is provided on the interlocking body 123 so as to rotate integrally with the interlocking body 123. The power transmitting body 121, the intermediate cylinder 122, and the interlocking body 123 are each provided with one or more serration portions (spline portions), and are fitted together to rotate integrally.

[0036] Furthermore, a one-way clutch (not shown) is disposed between the intermediate cylinder 122 and the interlocking body 123. The one-way clutch is disposed on the intermediate cylinder 122, and transmits rotational force in one direction from the intermediate cylinder 122 to the interlocking body 123 by a ratchet engaging with the interlocking body 123.

[0037] With this configuration, the crankshaft 16a is rotated by the force applied to the pedal 17, and the manual driving force generated by this rotation is transmitted to the front sprocket 19a via the manual power transmission body 121, the intermediate cylinder body 122, the one-way clutch (not shown), and the interlocking body 123. When the front sprocket 19a is rotated by the manual driving force, the chain 18 attached to the front sprocket 19a rotates, causing the rear sprocket 19b and the rear wheel 13 to rotate.

[0038] Additionally, an auxiliary driving force from the motor 110 is transmitted to the interlocking body 123 via the speed reducer 130. In other words, the rotation of the interlocking body 123 can be assisted by the auxiliary driving force from the motor 110, so that the front sprocket 19a, the rear sprocket 19b, and the rear wheel 13 can be rotated in accordance with the rotation of the interlocking body 123.

[0039] The reduction mechanism 130 is an example of a third rotation mechanism having a gear that transmits rotational force from the motor 110 to the crank rotation mechanism 120. The reduction mechanism 130 is configured so that the rotational torque of the motor 110 (i.e., the auxiliary driving force) is amplified and transmitted to the interlocking body 123. Specifically, as shown in FIG. 2 , the reduction mechanism 130 has a large diameter gear 131 and a small diameter gear 132. As described above, the large diameter gear 131 rotates in response to the rotation of the motor shaft 113 of the motor 110.

[0040] In the reduction mechanism 130, the small diameter gear 132 rotates integrally with the large diameter gear 131 on the same rotation axis. The small diameter gear 132 fits into the gear portion of the interlocking body 123. When the small diameter gear 132 rotates, the interlocking body 123 rotates.

[0041] As described above, in this embodiment, the auxiliary driving force generated by the motor 110 is transmitted to the interlocking member 123 via the reduction gear mechanism 130. That is, when the rotor 112 and the motor shaft 113 of the motor 110 rotate, the interlocking member 123 also rotates, causing the front sprocket 19a to rotate. This causes the rear wheel 13 to rotate via the chain 18 and the rear sprocket 19b.

[0042] The crank rotation sensor unit 140 is an example of a fourth rotation mechanism having a sensor shaft for detecting the rotation of the crankshaft 16a. Specifically, the crank rotation sensor unit 140 has a gear-shaped rotor 141 having the sensor shaft as its rotation axis, and a photodetector (not shown). The rotor 141 of the crank rotation sensor unit 140 is provided to rotate integrally with the intermediate cylinder body 122.

[0043] The rotation of the rotor 141 is detected by a detector such as a photodetector. For example, the photodetector has a light-emitting portion and a light-receiving portion arranged to face each other. The light-emitting portion and the light-receiving portion are fixed to, for example, the substrate 150 or the case 160. The rotor 141 is positioned so that its teeth block the path of light from the light-emitting portion to the light-receiving portion. As the rotor 141 rotates, the teeth block the light, so the rotation speed of the rotor 141 is detected based on the number of times the light received by the light-receiving portion is blocked (or the number of times light is successfully received) and the number of teeth on the rotor 141. Because the rotor 141, the intermediate cylinder 122, and the crankshaft 16a rotate integrally, the rotation speed of the rotor 141 coincides with the rotation speed of the crankshaft 16a. In this way, the crank rotation sensor 140 can detect the rotation speed of the crankshaft 16a.

[0044] The crank rotation sensor unit 140 may have any configuration as long as it can detect the rotation speed of the crankshaft 16a. The motor unit 100 may also include a motor rotation sensor that detects the rotation speed of the motor 110. The motor unit 100 may also include a pedal force sensor that detects the human driving force generated by the rotation of the crankshaft 16a based on the pedal force applied to the pedal 17.

[0045] The substrate 150 is a substrate on which various electronic components that constitute the control circuit 170 for controlling the operation of the motor unit 100 are mounted. The electronic components include one or more integrated circuits including a power supply IC (Integrated Circuit), electrolytic capacitors, capacitors, transistors, diodes, resistive elements, connectors, etc. The substrate 150 is, for example, a printed wiring board. Metal wiring is provided on the substrate 150 to electrically connect the electronic components.

[0046] The substrate 150 has a first main surface 150a and a second main surface 150b opposite the first main surface 150a. The first main surface 150a and the second main surface 150b are a pair of flat surfaces parallel to each other. As shown in FIG. 2, a plurality of electronic components are mounted on the first main surface 150a. The stator 111 and rotor 112 of the motor 110 are disposed on the second main surface 150b side of the substrate 150. The motor shaft 113 and crankshaft 16a of the motor 110 are disposed so as to intersect with the substrate 150. The four rotation mechanisms (motor 110, crank rotation mechanism 120, reduction mechanism 130, and crank rotation sensor unit 140) included in the motor unit 100 are disposed so that their rotation axes are perpendicular to the first main surface 150a of the substrate 150. The substrate 150 is fixed to the case 160 using fastening members such as screws. The specific configuration of the substrate 150 will be described later.

[0047] The case 160 constitutes most of the outer shell of the motor unit 100. The circuit board 150 is housed and fixed in the case 160. The case 160 also houses the motor 110, the reduction mechanism 130, the crank rotation sensor unit 140, and part of the crank rotation mechanism 120. The crank shaft 16a of the crank rotation mechanism 120 is disposed so as to pass through the case 160. Both ends of the crank shaft 16a are located outside the case 160, and are connected to crank arms 16b.

[0048] The case 160 includes a first divided body 161 and a second divided body 162. The first divided body 161 and the second divided body 162 are assembled and fixed together with fastening members (not shown) such as screws to form the case 160. Specifically, the first divided body 161 and the second divided body 162 are each formed in a cylindrical shape with a bottom, and are arranged with their openings facing each other and with the leading ends of their outer peripheral walls facing each other. The leading ends of the outer peripheral walls are provided with flanges with through holes, and the first divided body 161 and the second divided body 162 are fixed together with screws inserted into the through holes. Note that a packing or the like may be provided between the leading ends of the outer peripheral walls of the first divided body 161 and the second divided body 162 to prevent moisture and the like from entering.

[0049] The first divided body 161 and the second divided body 162 are each formed using a metal material such as an aluminum alloy, a magnesium alloy, stainless steel, or steel, but may also be formed using carbon or resin. The first divided body 161 and the second divided body 162 are each integrally formed by die casting, injection molding, or the like.

[0050] The control circuit 170 is mounted on the substrate 150. The control circuit 170 includes a power supply circuit that generates power to be supplied to the motor 110, i.e., power for rotating the motor shaft 113. For example, the power supply circuit is a power supply IC including a linear regulator or a DC / DC converter. The control circuit 170 also includes a detection circuit that detects the rotation of the crank shaft 16a based on the rotation of the rotor 141 of the crank rotation sensor unit 140. For example, the detection circuit includes the above-mentioned photodetector. The control circuit 170 may also include circuits for controlling lighting devices such as a headlight and a taillight provided on the electric bicycle 1, as well as electronic devices such as a display unit and an operation unit.

[0051] [Main characteristic configuration] Next, the main characteristic configuration of the motor unit 100 according to this embodiment will be described with reference to FIGS.

[0052] Fig. 3 is a plan view showing the positional relationship between the rotation mechanism and the substrate 150 included in the motor unit 100 according to the present embodiment. Fig. 4 is a plan view of the substrate 150 included in the motor unit 100 according to the present embodiment.

[0053] 3 and 4, the substrate 150 according to this embodiment is provided so as to collectively surround the rotation shafts of the four rotation mechanisms included in the motor unit 100. The shape of the substrate 150 in a plan view is a horizontally long U-shape (a horizontally long horseshoe shape). The rotation shafts of the four rotation mechanisms are arranged in the U-shaped space formed by the substrate 150. The specific scope of the U-shaped space will be described later.

[0054] The four rotation mechanisms are the motor 110, the crank rotation mechanism 120, the reduction mechanism 130, and the crank rotation sensor unit 140. The rotation axes of the motor 110, the crank rotation mechanism 120, the reduction mechanism 130, and the crank rotation sensor unit 140 intersect with the first main surface 150a of the substrate 150. Specifically, the rotation axes of the motor 110, the crank rotation mechanism 120, the reduction mechanism 130, and the crank rotation sensor unit 140 are perpendicular to the first main surface 150a of the substrate 150. In FIG. 4, the rotation axes of the motor 110, the crank rotation mechanism 120, the reduction mechanism 130, and the crank rotation sensor unit 140 are represented as points P1, P2, P3, and P4, respectively.

[0055] The substrate 150 has four recesses on its outer periphery in plan view that correspond one-to-one to the four rotation mechanisms. Specifically, as shown in Fig. 4, the substrate 150 includes, on its outer periphery in plan view, the four recesses: a first recess 151, a second recess 152, a third recess 153, and a fourth recess 154. At least a part of the corresponding rotation mechanism is disposed in each of the four recesses.

[0056] Specifically, the motor shaft 113 is disposed in the first recess 151. The crankshaft 16a is disposed in the second recess 152. In this embodiment, the human power transmission body 121 is disposed in the second recess 152. The large diameter gear 131 is disposed in the third recess 153. The shaft portion of the rotating body 141 is disposed in the fourth recess 154.

[0057] 4, dashed circles C1, C2, C3, and C4 are illustrated with points P1, P2, P3, and P4 at their centers. Each of the circles C1, C2, C3, and C4 represents the approximate range of a portion of the corresponding rotation mechanism that is located at the same height as the substrate 150 (the position in the axial direction of the rotation shaft). For example, the circle C1 represents the motor shaft 113 of the motor 110 that corresponds to the first recess 151. The circle C2 represents the human power transmission body 121 of the crank rotation mechanism 120 that corresponds to the second recess 152. The circle C3 represents the large-diameter gear 131 of the reduction mechanism 130 that corresponds to the third recess 153. The circle C4 represents the shaft portion of the rotating body 141 of the crank rotation sensor unit 140 that corresponds to the fourth recess 154.

[0058] Furthermore, "component A is placed in the recess" means that at least a portion of component A exists within the recess (internal space of the recess). The "internal space" of the recess refers to the space surrounded by the extended surfaces of the first and second main surfaces 150a and 150b of the substrate 150, the inner surface (inner wall) of the recess, and the opening surface of the recess. The extended surface of the first main surface 150a refers to a virtual plane obtained by extending the first main surface 150a directly into the recess. The same applies to the extended surface of the second main surface 150b. In other words, the "internal space" of the recess refers to a plate-like space whose shape in a planar view of the substrate 150 is determined by the inner surface (inner wall) of the recess and the opening surface of the recess, and whose thickness is the same as that of the substrate 150. In this embodiment, the inner surfaces of the first recess 151, the second recess 152, the third recess 153, and the fourth recess 154 all have an arc shape centered on the rotation axis of the corresponding rotation mechanism in a planar view of the substrate 150. Therefore, the inner surface of the recess means the arc portion in a plan view of the substrate 150. The opening surface of the recess corresponds to a straight line (a chord of a circle) connecting both ends of the inner surface (i.e., the arc) of the recess in a plan view of the substrate 150.

[0059] 4, the central axis (point P1) of the motor shaft 113 is located within the first recess 151 or on the opening surface of the first recess 151. The central axis (point P2) of the crankshaft 16a is located within the second recess 152 or on the opening surface of the second recess 152. Furthermore, the central axis (point P3) of the large-diameter gear 131 is located not within the third recess 153 but outside the third recess 153. The central axis (point P4) of the shaft portion of the rotating body 141 is located not within the fourth recess 154 but outside the fourth recess 154.

[0060] The diameter of the fourth recess 154 is shorter than the diameter of the first recess 151. The diameter of the first recess 151 is shorter than the diameter of the second recess 152. The diameter of the second recess 152 is shorter than the diameter of the third recess 153. Note that the "diameter" of a recess is twice the distance (radius) from the central axis (points P1 to P4) of the corresponding rotating body to the inner surface of the recess.

[0061] In this embodiment, the fourth recess 154, the second recess 152, and the third recess 153 are arranged side by side in this order along the outer periphery of the substrate 150. The first recess 151 is arranged on the inner wall of the third recess 153. That is, the opening surface of the first recess 151 is arranged on the inner wall of the third recess 153. Therefore, a portion of the motor shaft 113 arranged in the first recess 151 is also located in the third recess 153. That is, the motor shaft 113 is arranged to straddle the first recess 151 and the third recess 153.

[0062] Furthermore, substrate 150 includes, in a plan view, a base 155 that is elongated in a first direction, a first protrusion 156, and a second protrusion 157. The first direction is a direction from point P2 (the central axis of crankshaft 16a) toward point P1 (the central axis of motor shaft 113). First protrusion 156 protrudes from one end of base 155 in the first direction. Second protrusion 157 protrudes from the other end of base 155 in the first direction on the same side as first protrusion 156. Base 155 corresponds to the bottom portion of the U-shape, and first protrusion 156 and second protrusion 157 correspond to the two vertical bar portions of the U-shape.

[0063] For convenience, the first convex portion 156 is considered to be a portion located on the positive side of the second direction with respect to a virtual line that is parallel to the first direction and passes through the midpoint of the arc-shaped first recess 151. The second direction is a direction perpendicular to the first direction, as shown in FIG. 4 . The second convex portion 157 is considered to be a portion located on the positive side of the second direction with respect to a virtual line that is parallel to the first direction and passes through the midpoint of the arc-shaped second recess 152. The base 155 is considered to be a portion of the substrate 150 other than the first convex portion 156 and the second convex portion 157. In this embodiment, the first convex portion 156 is thicker (wider in the first direction) than the second convex portion 157, but is not limited to this.

[0064] The rotation axes (points P1 to P4) of the four rotation mechanisms are disposed in a space surrounded by base 155, first convex portion 156, and second convex portion 157 in plan view, i.e., in a U-shaped space. The U-shaped space is the space between base 155 and a line segment connecting the tips of first convex portion 156 and second convex portion 157 in the second direction. In plan view, a line segment connecting any two of the rotation axes (points P1 to P4) of the four rotation mechanisms does not intersect with substrate 150. In other words, in plan view, a rectangle having points P1 to P4 as vertices does not overlap with substrate 150.

[0065] As described above, in the motor unit 100 according to this embodiment, the four rotation mechanisms are respectively arranged in corresponding recesses. The substrate 150 does not have a through-hole for passing the rotation shaft of the rotation mechanism. There is no need to pass the rotation shaft through the through-hole of the substrate 150, and the substrate 150 can be placed laterally relative to the rotation shaft. This makes it easier to assemble the substrate 150 and the four rotation mechanisms, improving the ease of assembly of the motor unit 100.

[0066] Furthermore, the control circuit 170 is mounted on the substrate 150, and the motor unit 100 does not need to include any other substrates. This reduces the number of components included in the motor unit 100. The reduced number of components improves assembly workability of the motor unit 100, and also makes it possible to reduce the weight and size of the motor unit 100.

[0067] As described above, the planar shape of the substrate 150 is not a geometrically regular shape such as a rectangle, but a relatively complex shape. Generally, the substrate 150 is formed by cutting out a rectangular standard-length substrate into a predetermined shape. Therefore, when the substrate 150 having a complex shape is cut out from the standard-length substrate, the standard-length substrate will have a large portion that is not used as the substrate 150 (waste substrate), which causes problems such as reduced productivity, increased environmental impact, and increased costs.

[0068] In contrast, in this embodiment, the first protrusion 156 can be inserted into the second recess 152. In other words, when two substrates 150 are prepared and one of the substrates 150 is rotated 180 degrees and placed, the first protrusion 156 of one of the substrates 150 can be inserted into the second recess 152 of the other substrate. This makes it possible to reduce the number of discarded substrates. Below, a method for cutting two substrates 150 from one fixed-length substrate 200 will be described with reference to FIG. 5.

[0069] 5 is a plan view illustrating a method for cutting out the substrate 150 shown in FIG. 4. The fixed-length substrate 200 is a substrate from which two substrates 150 are cut out, and has a rounded rectangular shape in a plan view. The two substrates 150 include a first substrate 150A and a second substrate 150B. The first substrate 150A and the second substrate 150B have the same shape and size as the substrate 150 shown in FIG. 4.

[0070] Specifically, first substrate 150A and second substrate 150B each have a first recess 151, a second recess 152, a third recess 153, and a fourth recess 154 shown in Fig. 4 on their outer peripheries in a plan view. In Fig. 5, first recess 151, second recess 152, third recess 153, and fourth recess 154 of first substrate 150A are represented as first recess 151A, second recess 152A, third recess 153A, and fourth recess 154A. Similarly, first recess 151, second recess 152, third recess 153, and fourth recess 154 of second substrate 150B are represented as first recess 151B, second recess 152B, third recess 153B, and fourth recess 154B.

[0071] Similarly, first substrate 150A and second substrate 150B each have, in plan view, base 155, first convex portion 156, and second convex portion 157 shown in Fig. 4. In Fig. 5, base 155, first convex portion 156, and second convex portion 157 of first substrate 150A are represented as base 155A, first convex portion 156A, and second convex portion 157A. Similarly, base 155, first convex portion 156, and second convex portion 157 of second substrate 150B are represented as base 155B, first convex portion 156B, and second convex portion 157B.

[0072] The first substrate 150A and the second substrate 150B are arranged in point symmetry with the center Q of the standard-length substrate 200 as the center of symmetry. The center Q corresponds to the intersection of the diagonals of the standard-length substrate 200 in a plan view. The third recess 153A of the first substrate 150A and the third recess 153B of the second substrate 150B face each other. The portion of the standard-length substrate 200 between the third recess 153A and the third recess 153B is an unnecessary portion 201, which is a so-called discarded substrate. The unnecessary portion 201 has a shape that combines the third recesses 153A and 153B (two arch shapes) and is small.

[0073] Furthermore, the first protrusion 156A of the first substrate 150A is disposed within the second recess 152B of the second substrate 150B. The first protrusion 156A occupies 75% or more of the space within the second recess 152B. The first protrusion 156A may occupy 80% or more, 85% or more, 90% or more, or 95% or more of the space within the second recess 152B. The larger the proportion occupied by the first protrusion 156A, the less waste there is in the fixed-length substrate 200, improving productivity. Furthermore, the larger the proportion occupied by the first protrusion 156A, the more space available for arranging electronic components relative to the first protrusion 156A, thereby increasing the degree of freedom in layout.

[0074] As such, the planar shape of substrate 150 in this embodiment has a shape such that, when the two substrates are considered to be first substrate 150A and second substrate 150B, with third recess 153A of first substrate 150A and third recess 153B of second substrate 150B facing each other, a portion of second substrate 150B can be inserted into second recess 152A of first substrate 150A, and a portion of first substrate 150A can be inserted into second recess 152B of second substrate 150B.

[0075] 5, when two substrates 150 are cut out from a fixed-length substrate 200, the unused portions of the substrate 150 are an unnecessary portion 201 in the center and an unnecessary portion 202 on the periphery. The spaces within the second recesses 152A and 152B are not unused portions, but are used as the first protrusions 156A and 156B. This provides the advantages of improved productivity, reduced environmental impact, and reduced costs.

[0076] Although an example in which two substrates 150 are cut out from fixed-length substrate 200 has been shown, a larger substrate may be used to cut out multiple (four or more) substrates 150.

[0077] [summary] The main features of the motor unit 100 and the electric bicycle 1, which is an example of an electric vehicle, explained based on the above embodiment will be described below.

[0078] Motor unit 100 according to a first aspect of the present invention is a motor unit used in an electric vehicle, and includes a substrate 150 and four rotation mechanisms arranged so that each rotation axis is perpendicular to the main surface of substrate 150. Substrate 150 has four recesses on its outer periphery in a plan view, which are provided in one-to-one correspondence with the four rotation mechanisms. At least a portion of the corresponding rotation mechanism is disposed in each of the four recesses.

[0079] In this way, the four rotation mechanisms are each disposed in a corresponding recess, and no through-hole is provided in the substrate 150 for passing the rotation shaft of the rotation mechanism. There is no need to pass the rotation shaft through the through-hole of the substrate 150, and the substrate 150 can be placed laterally relative to the rotation shaft. This improves the assembly workability of the substrate 150 and the four rotation mechanisms. Therefore, a motor unit 100 with high assembly workability can be realized.

[0080] Furthermore, by providing a recess corresponding to the rotation mechanism, the gap between the substrate and the rotation mechanism can be reduced. For example, by making the inner surface of the recess arc-shaped in plan view, the distance between the substrate (inner surface of the recess) and the rotation mechanism can be made constant, thereby reducing wasted space. This allows the motor unit 100 to be made smaller and lighter.

[0081] A motor unit 100 according to a second aspect of the present invention is the motor unit according to the first aspect, and the four rotation mechanisms include a motor (first rotation mechanism) 110 having a motor shaft 113, a crank rotation mechanism (second rotation mechanism) 120 having a crankshaft 16a, a reduction mechanism (third rotation mechanism) 130 having a large-diameter gear 131 that transmits rotational force from the motor 110 to the crank rotation mechanism 120, and a crank rotation sensor unit (fourth rotation mechanism) 140 having a rotor 141 (sensor shaft) for detecting rotation of the crankshaft 16a. The four recesses include a first recess 151 in which the motor shaft 113 is disposed, a second recess 152 in which the crankshaft 16a is disposed, a third recess 153 in which the large-diameter gear 131 is disposed, and a fourth recess 154 in which the shaft portion of the rotor 141 is disposed.

[0082] This makes it possible to improve the assembly workability of the motor unit 100 including the crank rotation sensor section 140 and the speed reduction mechanism 130, and to achieve a reduction in size and weight.

[0083] The motor unit 100 according to the third aspect of the present invention is the motor unit according to the second aspect, in which the fourth recess 154, the second recess 152 and the third recess 153 are arranged in this order along the outer periphery of the substrate 150.

[0084] As a result, the rotating body 141 of the crank rotation sensor unit 140 and the reduction mechanism 130 are positioned near the crank shaft 16a corresponding to the second recess 152, thereby enabling smooth transmission of rotational force between the rotating mechanisms corresponding to the recesses.

[0085] A motor unit 100 according to a fourth aspect of the present invention is the motor unit according to the second or third aspect, in which the first recess 151 is provided on the inner wall of the third recess 153.

[0086] This allows the motor 110 and the speed reduction mechanism 130 to be disposed close to each other, so that the rotational force from the motor 110 can be transmitted to the speed reduction mechanism 130 smoothly.

[0087] A motor unit 100 according to a fifth aspect of the present invention is the motor unit according to any one of the second to fourth aspects, wherein the substrate 150 includes, in a plan view, a base 155 that is elongated in a first direction, a first convex portion 156 that protrudes from one end of the base 155 in the first direction, and a second convex portion 157 that protrudes from the other end of the base 155 in the first direction on the same side as the first convex portion 156. In a plan view of the substrate 150, the rotation shafts of the four rotation mechanisms are disposed in a space (U-shaped space) surrounded by the base 155, the first convex portion 156, and the second convex portion 157.

[0088] As a result, the rotation shafts of the four rotation mechanisms are disposed in the U-shaped space of the substrate 150, making it possible to effectively utilize the space, thereby achieving a reduction in size and weight of the motor unit 100.

[0089] The motor unit 100 according to a sixth aspect of the present invention is a motor unit according to any one of the second to fifth aspects, wherein the substrate 150 has, in a planar view, a first convex portion 156 that can be inserted into the second recess 152, and when inserted into the second recess 152, the first convex portion 156 occupies 75% or more of the space within the second recess 152 in a planar view.

[0090] This makes it possible to cut out two substrates 150 as a set from one fixed-length substrate 200. The portion inside the second recess 152 of one substrate 150 can be effectively used as the first protrusion 156 of the other substrate 150, thereby reducing the amount of discarded substrates. This reduces waste, and offers the advantages of improved productivity, reduced environmental impact, and lower costs.

[0091] A motor unit 100 according to a seventh aspect of the present invention is a motor unit according to any one of the second to sixth aspects, and when the two substrates, each of which is a substrate 150, are considered to be a first substrate 150A and a second substrate 150B, the planar shape of substrate 150 has a shape that allows a portion of second substrate 150B to be inserted into second recess 152A of first substrate 150A, and a portion of first substrate 150A to be inserted into second recess 152B of second substrate 150B, with third recesses 153A and 153B of first substrate 150A and second substrate 150B facing each other.

[0092] This makes it possible to cut out two substrates 150 as a set from one fixed-length substrate 200. The portion inside the second recess 152 of one substrate 150 can be used as part of the other substrate 150, so it is possible to reduce the amount of so-called discarded substrates. This reduces waste, and offers the advantages of improved productivity, reduced environmental impact, and reduced costs.

[0093] The motor unit 100 according to the eighth aspect of the present invention is a motor unit according to any one of the second to seventh aspects, and the substrate 150 is mounted with a power supply circuit that generates power for rotating the motor shaft 113 and a detection circuit that detects the rotation of the crankshaft 16a based on the rotation of the sensor shaft.

[0094] As a result, the power supply circuit and detection circuit are mounted on the board 150, and the motor unit 100 does not need to include any other boards. This reduces the number of parts included in the motor unit 100, improving the ease of assembly of the motor unit 100. Furthermore, the motor unit 100 can be made smaller and lighter.

[0095] An electric bicycle 1, which is an electric vehicle according to the ninth aspect of the present invention, comprises a motor unit 100 according to any one of the first to eighth aspects, a rear wheel (wheel) 13 to which the rotational force of at least one of the four rotation mechanisms is transmitted, and a frame 11 that supports the motor unit 100 and the rear wheel 13.

[0096] This makes it possible to realize an electric bicycle 1 equipped with a motor unit 100 that is easy to assemble.

[0097] (others) The motor unit and the electric vehicle according to the present invention have been described above based on the above-mentioned embodiment, but the present invention is not limited to the above-mentioned embodiment.

[0098] For example, in the electric bicycle 1, the rotational force of the motor 110 is transmitted to the rear wheel 13, but this is not limited to this. The rotational force of the motor 110 may be transmitted to the front wheel 12. Alternatively, the rotational force of the motor 110 may be transmitted to both the front wheel 12 and the rear wheel 13.

[0099] Furthermore, for example, electric vehicles are not limited to two-wheeled bicycles. They may be tricycles with two front wheels and two rear wheels. Alternatively, electric vehicles may be bicycles with four or more wheels. Furthermore, electric vehicles may be specific small motorized bicycles such as electric kick scooters.

[0100] For example, although the four rotation mechanisms of the motor unit 100 are the motor 110, the crank rotation mechanism 120, the reduction mechanism 130, and the crank rotation sensor unit 140 in the example shown, the present invention is not limited to this. For example, the four rotation mechanisms may include another rotation mechanism that transmits the force generated by the motor 110. The motor unit 100 may also be equipped with five or more rotation mechanisms. In this case, the substrate 150 may be provided with five or more recesses on the outer periphery in a plan view that correspond one-to-one to the five or more rotation mechanisms.

[0101] Furthermore, for example, the rotation axes of the four or more rotation mechanisms included in the motor unit 100 may be inclined at an angle to intersect with the first main surface 150a of the substrate 150. In other words, each rotation axis does not have to be perpendicular to the first main surface 150a of the substrate 150.

[0102] Furthermore, for example, the positional relationship between the first recess 151, the second recess 152, the third recess 153, and the fourth recess 154 is not limited to the example described above. For example, the fourth recess 154 may be disposed between the second recess 152 and the third recess 153.

[0103] Furthermore, for example, at least one rotation shaft of the four rotation mechanisms does not have to be provided inside the U-shaped space of the substrate 150. For example, the crankshaft 16a and the shaft of the large diameter gear 131 may be provided inside the U-shaped space, and the shaft portion of the motor shaft 113 and the rotor 141 may be provided outside the U-shaped space.

[0104] Further, for example, the second protrusion 157 may have a shape that allows it to be inserted into the first recess 151.

[0105] In addition, the present invention also includes forms obtained by applying various modifications to each embodiment that a person skilled in the art would think of, and forms realized by arbitrarily combining the components and functions of each embodiment within the scope of the present invention. [Explanation of symbols]

[0106] 1. Electric bicycles (electric vehicles) 11 frames 12 Front wheels 13 Rear wheel (wheel) 16a crankshaft 100 Motor unit 110 Motor (first rotation mechanism) 113 Motor shaft 120 Crank rotation mechanism (second rotation mechanism) 130 Reduction mechanism (third rotation mechanism) 131 Large diameter gear 140 crank rotation sensor unit (fourth rotation mechanism) 141 rotating body 150, 150A, 150B board 151, 151A, 151B First recess 152, 152A, 152B Second recess 153, 153A, 153B Third recess 154, 154A, 154B Fourth recess 155, 155A, 155B base 156, 156A, 156B First convex part 157, 157A, 157B Second convex part 160 cases 170 Control circuit

Claims

1. A motor unit for use in an electric vehicle, A substrate; four rotation mechanisms arranged such that each rotation axis intersects with the main surface of the substrate; the substrate has four recesses provided in a one-to-one correspondence with the four rotation mechanisms on an outer periphery thereof in a plan view, At least a part of a corresponding rotation mechanism is disposed in each of the four recesses. Motor unit.

2. The four rotation mechanisms are: a first rotation mechanism having a motor shaft; a second rotation mechanism having a crankshaft; a third rotation mechanism having a gear that transmits a rotational force from the first rotation mechanism to the second rotation mechanism; a fourth rotation mechanism having a sensor shaft for detecting rotation of the crankshaft, The four recesses are: a first recess in which the motor shaft is disposed; a second recess in which the crankshaft is disposed; a third recess in which the gear is disposed; a fourth recess in which the sensor shaft is disposed, The motor unit according to claim 1 .

3. the fourth recess, the second recess, and the third recess are arranged in this order along the outer periphery of the substrate. The motor unit according to claim 2 .

4. The first recess is provided on an inner wall of the third recess. The motor unit according to claim 2 or 3.

5. The substrate, in a plan view, a base portion elongated in a first direction; a first protrusion protruding from one end of the base in the first direction; a second protrusion protruding from the other end of the base in the first direction on the same side as the first protrusion, In a plan view of the substrate, a rotation shaft of each of the four rotation mechanisms is disposed in a space surrounded by the base portion, the first convex portion, and the second convex portion. The motor unit according to claim 2 or 3.

6. the substrate has, in a plan view, a first protrusion that can be inserted into the second recess; When the first protrusion is inserted into the second recess, the first protrusion occupies 75% or more of a space within the second recess in a plan view. The motor unit according to claim 2 or 3.

7. When two substrates, each of which is the substrate, are regarded as a first substrate and a second substrate, the shapes of the substrates in a plan view have a shape that allows a part of the second substrate to be inserted into the second recess of the first substrate and a part of the first substrate to be inserted into the second recess of the second substrate, with the third recess of the first substrate and the third recess of the second substrate facing each other. The motor unit according to claim 2 or 3.

8. The substrate is mounted with a power supply circuit that generates power for rotating the motor shaft and a detection circuit that detects rotation of the crankshaft based on rotation of the sensor shaft. The motor unit according to claim 2 or 3.

9. A motor unit according to any one of claims 1 to 3; a wheel to which the rotational force of at least one of the four rotation mechanisms is transmitted; a frame supporting the motor unit and the wheels, Electric vehicle.

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