Rotary device

Abstract

To provide a rotary device with improved torque during startup.SOLUTION: A rotary device 100 includes: output shafts (16, 23); a one-way clutch 31; a motor 40 directly or indirectly connected with the output shafts (16, 23) through the one-way clutch 31; and a controller 50. The motor 40 can rotate in a first direction R1 and a second direction R2 and the one-way clutch 31 transmits the rotation of the motor 40 in the first direction. The controller 50 outputs a first signal Sa, and after outputting the first signal Sa, it outputs a second signal Sb. The motor 40 with the first signal Sa input rotates in the second direction R2, while the motor 40 with the second signal Sb input rotates in the first direction R1.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to rotating equipment. [Background technology]

[0002] Conventionally, there is known a rotating device in which the rotational force of a motor is transmitted to a shaft via a gear and a one-way clutch. An example of such a rotating device is a motor drive unit of an electrically assisted bicycle. For example, Patent Document 1 discloses an electrically assisted bicycle equipped with a controller that controls the driving force of the motor in response to the pedaling force while maintaining the motor voltage at or above the voltage that provides the motor rotation speed corresponding to the vehicle speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-062681 A Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of rotating equipment, it is sometimes desirable to obtain maximum torque at startup under high load. However, since the torque of the motor varies depending on the difference between the rotation angle of the rotor and the rotation angle of the rotor detected by the sensor, appropriate torque may not be obtained depending on the rotor position at startup. An example of an object of the present invention is to improve the torque of a rotating device at startup. [Means for solving the problem]

[0005] The rotating device of the present invention comprises an output shaft, a one-way clutch, a motor directly or indirectly connected to the output shaft via the one-way clutch, and a control device, wherein the motor is rotatable in a first direction and a second direction that is opposite to the first direction, the one-way clutch transmits the rotation of the motor in the first direction, and the control device outputs a first signal and, after outputting the first signal, outputs a second signal, and the motor that receives the first signal rotates in the second direction, and the motor that receives the second signal rotates in the first direction. [Brief description of the drawings]

[0006] [Figure 1] 1 is a schematic diagram of a rotating device according to an embodiment that is an example of the present invention; [Diagram 2] 1 is a diagram showing a configuration of a motor drive control device and a motor of a rotating device according to an embodiment that is an example of the present invention. [Diagram 3] 4 is a flowchart showing an example of a flow of control by a motor drive control device for a rotating device according to an embodiment which is an example of the present invention. [Figure 4] 1 is a plot showing an example of the relationship between the rotor rotation angle (electrical angle) and the motor torque (percentage relative to maximum torque) within a range in which the rotor rotation angle detected by a sensor is constant. [Diagram 5] FIG. 13 is a schematic diagram of a rotating device according to a modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] For convenience in describing the embodiment of the present invention, the direction of arrow a along the axis X in Fig. 1 (direction from the motor 40 to the first gear 11) is defined as one side. The direction of arrow b along the axis X (direction from the first gear 11 to the motor 40) is defined as the other side. Here, the direction of arrow ab is referred to as the axial direction.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram of a rotating device 100 according to this embodiment. As shown in Fig. 1, the rotating device 100 includes a reduction gear set 10 including gears (a first gear 11, a second gear 12, a third gear 13, a fourth gear 14, and a fifth gear 15) as other members and an output gear 16 constituting a part of the output shaft, a first shaft 21, a second shaft 22, a third shaft 23 constituting another part of the output shaft, a first one-way clutch 31, a second one-way clutch 32, a third one-way clutch 33, a motor 40, a motor drive control device 50 as a control device, and a housing 60.

[0009] In Fig. 1, the first gear 11, the second gear 12, the third gear 13, the fourth gear 14, the fifth gear 15, the output gear 16, the first one-way clutch 31, the second one-way clutch 32, and the third one-way clutch 33 are shown as schematic cross-sectional views for the sake of convenience, but this does not necessarily mean that all cross-sections are on the same plane. In Fig. 1, the teeth of the first gear 11, the second gear 12, the third gear 13, the fourth gear 14, the fifth gear 15, and the output gear 16 fixed to the shaft S of the motor 40 are omitted.

[0010] The motor 40 is rotatable around the axis X in a first direction R1 and a second direction R2 that is the opposite direction to the first direction R1. In this embodiment, when the output shaft (shaft S) of the motor 40 is viewed from one side in the axial direction (the direction of the arrow a) to the other side in the axial direction (the direction of the arrow b), the clockwise rotation direction is defined as the first direction R1, and the counterclockwise rotation direction is defined as the second direction R2.

[0011] The first gear 11 is an approximately cylindrical gear as a whole, directly connected to the output shaft (shaft S) of the motor 40. A cylindrical or approximately cylindrical first shaft 21 extends parallel to the axis X of the motor 40 in the vicinity of the first gear 11. The first shaft 21 is rotatably supported by the housing 60 via a bearing or the like (not shown).

[0012] The second gear 12 and the third gear 13 are coaxially arranged on the first shaft 21 in the order of proximity to the motor 40 (in the axial direction from the other side (arrow b direction) to one side (arrow a direction)). The second gear 12 and the third gear 13 may be arranged in any order, and the third gear 13 and the second gear 12 may be arranged in the order of proximity to the motor 40. The second gear 12 is a gear having a substantially annular shape as a whole, and is fixed to the first shaft 21 via the first one-way clutch 31. The second gear 12 meshes with the first gear 11. The inner peripheral surface of the second gear 12 (the peripheral surface on the side closer to the first shaft 21) is fixed to the outer peripheral surface of the first one-way clutch 31 (the peripheral surface on the side farther from the first shaft 21). The inner peripheral surface of the first one-way clutch 31 (the peripheral surface on the side closer to the first shaft 21) is fixed to the outer peripheral surface of the first shaft 21.

[0013] The first one-way clutch 31 is configured to transmit the rotation of the motor 40 in the first direction R1 to the first shaft 21 and not transmit the rotation of the motor 40 in the second direction R2 to the first shaft 21. When the motor 40 rotates in the first direction R1, the first gear 11 also rotates in the first direction R1. Then, the second gear 12 meshing with the first gear 11 rotates in the opposite direction to the first direction R1, that is, in the second direction R2. The first one-way clutch 31 transmits the rotation of the motor 40 in the first direction R1 to the first shaft 21 by transmitting the rotation of the second gear 12 in the second direction R2 to the first shaft 21. In addition, the first one-way clutch 31 does not transmit the rotation of the second gear 12 in the first direction R1 to the first shaft 21, and therefore does not transmit the rotation of the motor 40 in the second direction R2 to the first shaft 21.

[0014] The third gear 13 is a substantially disk-shaped gear, and is directly fixed to the first shaft 21. That is, the inner circumferential surface of the third gear 13 (the circumferential surface on the side closer to the first shaft 21) is fixed to the outer circumferential surface of the first shaft 21 by press-fitting or adhesive. Therefore, the third gear 13 rotates integrally with the first shaft 21. Note that the third gear 13 and the first shaft 21 may be formed as an integral member.

[0015] A cylindrical or substantially cylindrical second shaft 22 extends in the vicinity of the first shaft 21 in parallel with the axis X of the motor 40 and the first shaft 21. The second shaft 22 is rotatably supported by the housing 60 via a bearing or the like (not shown).

[0016] The fifth gear 15 and the fourth gear 14 are coaxially arranged on the second shaft 22 in the order of proximity to the motor 40 (in the axial direction from the other side (arrow b direction) to one side (arrow a direction)). The fourth gear 14 and the fifth gear 15 may be arranged in any order, and the fourth gear 14 and the fifth gear 15 may be arranged in the order of proximity to the motor 40. The fourth gear 14 is an approximately annular gear as a whole, and is fixed to the second shaft 22 via the second one-way clutch 32. The fourth gear 14 meshes with the third gear 13. The inner peripheral surface of the fourth gear 14 (the peripheral surface on the side closer to the second shaft 22) is fixed to the outer peripheral surface of the second one-way clutch 32 (the peripheral surface on the side farther from the second shaft 22). The inner peripheral surface of the second one-way clutch 32 (the peripheral surface on the side closer to the second shaft 22) is fixed to the outer peripheral surface of the second shaft 22.

[0017] The second one-way clutch 32 is configured to transmit the rotation of the motor 40 in the first direction R1 to the second shaft 22 and not transmit the rotation of the motor 40 in the second direction R2 to the second shaft 22. When the motor 40 rotates in the first direction R1, the third gear 13 rotates in the second direction R2. Then, the fourth gear 14 meshing with the third gear 13 rotates in the opposite direction to the second direction R2, that is, in the first direction R1. The second one-way clutch 32 transmits the rotation of the motor 40 in the first direction R1 to the second shaft 22 by transmitting the rotation of the fourth gear 14 in the first direction R1 to the second shaft 22. In addition, the second one-way clutch 32 does not transmit the rotation of the fourth gear 14 in the second direction R2 to the second shaft 22, and therefore does not transmit the rotation of the motor 40 in the second direction R2 to the second shaft 22.

[0018] The fifth gear 15 is a substantially disk-shaped gear, and is directly fixed to the second shaft 22. That is, the inner circumferential surface of the fifth gear 15 (the circumferential surface on the side closer to the second shaft 22) is fixed to the outer circumferential surface of the second shaft 22 by press-fitting or bonding. Therefore, the fifth gear 15 rotates integrally with the second shaft 22. Note that the fifth gear 15 and the second shaft 22 may be formed as an integral member.

[0019] Near the second shaft 22, the third shaft 23, which is cylindrical or approximately cylindrical, extends parallel to the axis X of the motor 40, the first shaft 21, and the second shaft 22. The third shaft 23 has an end 23a on one side and an end 23b on the other side. The third shaft 23 is rotatably supported by the housing 60 via a bearing or the like (not shown). The third shaft 23 penetrates the housing 60 in the axial direction. The end 23a on one side of the third shaft 23 protrudes from one side of the housing 60 (in the direction of the arrow a). The end 23b on the other side of the third shaft 23 protrudes from the other side of the housing 60 (in the direction of the arrow b). When the rotating device 100 is a motor drive unit of an electric-assisted bicycle, the third shaft 23 is a crankshaft.

[0020] An output gear 16 constituting a part of the output shaft is disposed near the end 23b on the other side of the third shaft 23 in the axial direction. The output gear 16 has a substantially annular gear portion 16a and a substantially cylindrical protruding portion 16b that is provided coaxially with the gear portion 16a and protrudes from the gear portion 16a to the other side in the axial direction (in the direction of the arrow b). If necessary, the protruding portion 16b may have a region formed in a gear shape or a region formed in a male screw shape. The gear portion 16a of the output gear 16 is accommodated inside the housing 60, and the protruding portion 16b of the output gear 16, together with the end 23b on the other side of the third shaft 23, penetrates the housing 60 and protrudes to the other side in the axial direction (in the direction of the arrow b).

[0021] The gear portion 16a of the output gear 16 is fixed to the third shaft 23 via the third one-way clutch 33. The output gear 16 meshes with the fifth gear 15. An inner circumferential surface (the circumferential surface on the side closer to the third shaft 23) of the gear portion 16a of the output gear 16 is fixed to an outer circumferential surface (the circumferential surface on the side farther from the third shaft 23) of the third one-way clutch 33. Also, an inner circumferential surface (the circumferential surface on the side closer to the third shaft 23) of the third one-way clutch 33 is fixed to the outer circumferential surface of the third shaft 23.

[0022] The third one-way clutch 33 is configured to transmit rotation in one direction, but not in other directions, of the rotation of the third shaft 23 relative to the output gear 16. For example, when the rotating device 100 is a motor drive unit of an electric power-assisted bicycle, when the crankshaft (third shaft 23) is rotated in the reverse direction by stepping on the pedals in the opposite direction, the third shaft 23 rotates in the first direction R1 relative to the output gear 16, but at this time, the rotation of the third shaft 23 is not transmitted to the output gear 16. On the other hand, when the crankshaft (third shaft 23) is rotated in the forward direction by stepping on the pedals to move the electric power-assisted bicycle forward, and the third shaft 23 rotates in the second direction R2 relative to the output gear 16, the rotation of the third shaft 23 is transmitted to the output gear 16. A chain ring (not shown) is fixed to the protruding portion 16b of the output gear 16 via a hub (not shown) or the like, and the driving force is transmitted to the rear wheel via a roller chain or the like hung on the chain ring. At that time, the rotational force of the motor 40 in the first direction R1 assists the rotation of the output gear 16 in the second direction R2, thereby reducing the force required to depress the pedal.

[0023] As described above, the motor 40 is connected to the first gear 11, the second gear 12, the first one-way clutch 31, the first shaft 21, the third gear 13, the fourth gear 14, the second one-way clutch 32, the second shaft 22, the fifth gear 15, and the output gear 16 in this order, and the motor 40 is further connected to the third shaft 23 via the third one-way clutch 33. Therefore, the motor 40 is directly or indirectly connected to the output gear 16 constituting one part of the output shaft and the third shaft 23 constituting another part of the output shaft via the first one-way clutch 31.

[0024] Fig. 2 is a diagram showing the configuration of a motor drive control device 50 and a motor 40 of a rotating device 100. The motor drive control device 50 has, for example, a control circuit 51 and a drive circuit 52. Note that the components of the motor drive control device 50 shown in Fig. 2 are only a part of the whole, and the motor drive control device 50 may have other components in addition to those shown in Fig. 2.

[0025] The motor 40 is, for example, a brushless DC motor having coils Lu, Lv, and Lw corresponding to three phases (U phase, V phase, and W phase). The motor 40 includes sensors (sensors 41u, 41v, and 41w) for detecting the rotation angle of a rotor (rotation angle of the motor) not shown. The sensors 41u, 41v, and 41w are disposed at positions corresponding to the coils Lu, Lv, and Lw, respectively. Within the range of rotation angles of the motor 40 that can be detected by the sensors 41u, 41v, and 41w, there exists a rotation angle at which the torque of the motor 40 exhibits a maximum value or a local maximum value.

[0026] In this embodiment, the sensors 41u, 41v, and 41w are Hall ICs and output signals according to the rotation angle of the rotor. The sensors 41u, 41v, and 41w are arranged around the rotor of the motor 40 at equal angular intervals (for example, 120 degrees from adjacent sensors). The sensors 41u, 41v, and 41w detect the magnetic poles of the rotor, and output signals whose voltages change according to the rotation of the rotor as rotation angle detection signals Hu, Hv, and Hw. The rotation angle detection signals Hu, Hv, and Hw are input to a control circuit 51 of the motor drive control device 50.

[0027] Here, the sensors 41u, 41v, and 41w are disposed at positions where at least one of the rotation angle detection signals Hu, Hv, and Hw switches when a rotation angle (e.g., 30°) at which the torque of the motor 40 indicates a maximum value or a local maximum value is detected. However, the arrangement of the sensors 41u, 41v, and 41w is not limited to this.

[0028] The control circuit 51 is, for example, a program processing device (e.g., a microcontroller) having a configuration in which a processor such as a CPU, various storage devices such as RAM and ROM, and peripheral circuits such as a counter (timer), an A / D conversion circuit, a D / A conversion circuit, a clock generation circuit, and an input / output I / F circuit are connected to each other via a bus or a dedicated line.

[0029] The control circuit 51 generates a drive control signal Sd for driving the motor 40 based on, for example, a drive command signal Sc input from the outside and indicating a target state of the operation of the motor 40, and controls the driving of the motor 40. For example, if the rotating device 100 is a motor drive unit of an electric-assisted bicycle, the drive command signal Sc may be a signal output as a result of a torque sensor detecting a pedaling force. For example, the control circuit 51 monitors the rotation state of the motor 40 by obtaining information such as the rotation angle and rotation speed of the rotor of the motor 40 based on the rotation angle detection signals Hu, Hv, and Hw from the sensors 41u, 41v, and 41w, and generates a drive control signal Sd so that the motor 40 is in a predetermined operating state, and provides the drive control signal Sd to the drive circuit 52. The drive control signal Sd is, for example, a PWM (Pulse Width Modulation) signal.

[0030] The drive circuit 52 excites the coils Lu, Lv, and Lw based on the drive control signal Sd, thereby driving the motor 40. The drive circuit 52 may include, for example, an inverter circuit that drives the coils Lu, Lv, and Lw of each phase, a pre-drive circuit that drives the inverter circuit in response to the drive control signal Sd, and a current detection circuit that detects the current flowing through the coils Lu, Lv, and Lw of each phase.

[0031] The motor drive control device 50 may be configured such that part or all of the control circuit 51 and part or all of the drive circuit 52 are packaged as a single integrated circuit device (IC), or the control circuit 51 and the drive circuit 52 are each packaged as separate integrated circuit devices.

[0032] Next, a description will be given of the flow of control of the rotating device 100 according to this embodiment by the motor drive control device 50. FIG.

[0033] First, the control circuit 51 waits for input of a drive command signal Sc (step S1). When the drive command signal Sc is input to the control circuit 51, the control circuit 51 detects the rotation angle detection signals Hu, Hv, and Hw from the sensors 41u, 41v, and 41w (step S2). The drive command signal Sc may be input to the control circuit 51 as a plurality of signals. Next, the control circuit 51 provides a drive control signal Sd to the drive circuit 52 so as to rotate (reversely rotate) the motor 40 in the second direction R2. The drive circuit 52 outputs to the motor 40 a current conduction pattern (first signal Sa) such that the motor 40 rotates (reversely rotates) in the second direction R2 (step S3).

[0034] The first signal Sa is a current pattern that does not switch the current-carrying phase among the U-phase, V-phase, and W-phase of the motor 40. That is, while the first signal Sa is being input, the magnetic field formed by the excited coils Lu, Lv, and Lw is constant. Therefore, the rotor of the motor 40 rotates slightly (reversely) in the second direction R2, and then stops due to the magnetic force between the coils Lu, Lv, and Lw as the stator and the rotor. As described above, the first one-way clutch 31 is configured not to transmit the rotation of the motor 40 in the second direction R2 to the first shaft 21. Therefore, the reverse rotation (rotation in the second direction R2) of the motor 40 caused by the first signal Sa is not transmitted to the members subsequent to the first shaft 21 that are connected to it (i.e., the first shaft 21, the third gear 13, the fourth gear 14, the second one-way clutch 32, the second shaft 22, the fifth gear 15, the output gear 16, the third one-way clutch 33, and the third shaft 23).

[0035] Here, the rotation angle of the motor 40, which receives the first signal Sa, until it rotates in the second direction and stops, is smaller than 360°. The rotation angle of the motor 40, which receives the first signal Sa and rotates in the second direction and stops, may be 180° or less, 120° or less, or 60° or less. The position at which the reverse rotation of the motor 40 stops varies depending on the number of slots of the stator, the number of magnetic poles of the rotor, etc. In this embodiment, the motor 40 is configured so that the torque indicates a maximum value or a local maximum value, or a value close to the maximum value or the local maximum value, at the position at which the reverse rotation stops.

[0036] Next, the control circuit 51 refers to the rotation angle detection signals Hu, Hv, Hw from the sensors 41u, 41v, 41w and judges whether the rotor has reached a predetermined rotation angle (in this embodiment, the rotation angle at which the torque of the motor 40 indicates a maximum or local maximum value, or a value close to the maximum or local maximum value) (step S4). The fact that the rotor has reached the predetermined rotation angle can be judged, for example, by at least one of the rotation angle detection signals Hu, Hv, Hw switching. If the rotor has not reached the predetermined rotation angle, steps S3 and S4 are repeated until it is confirmed that the rotor has reached the predetermined rotation angle (the rotor position has moved).

[0037] After confirming that the rotor has reached a predetermined rotation angle, the control circuit 51 provides a drive control signal Sd to the drive circuit 52 to rotate the motor 40 in the first direction R1 (forward rotation). The drive circuit 52 outputs to the motor 40 a current pattern (second signal Sb) that rotates the motor 40 in the first direction R1 (forward rotation) (step S5).

[0038] The control circuit 51 refers to the rotation angle detection signals Hu, Hv, and Hw from the sensors 41u, 41v, and 41w to determine whether the motor 40 has started rotating in the first direction R1 (step S6). If the motor 40 has not started rotating in the first direction R1, steps S5 and S6 are repeated until it is confirmed that the motor 40 has started rotating in the first direction R1.

[0039] After confirming that the motor 40 has started rotating in the first direction R1, the motor drive control device 50 continues to output the second signal Sb in accordance with the drive command signal Sc and the rotation angle detection signals Hu, Hv, Hw from the sensors 41u, 41v, 41w, thereby causing the motor 40 to continue rotating in the first direction R1 (step S7).

[0040] The motor 40 of the rotating device 100 according to this embodiment includes three Hall ICs (sensors 41u, 41v, and 41w). In a motor including three Hall ICs, the resolution for detecting the rotation angle of the rotor is typically 60°. This is because the output signal of the Hall IC switches every 60°, and the rotation of the rotor is detected by detecting the switching. Therefore, if the Hall ICs are arranged so that the rotation angle (electrical angle) of the rotor matches the rotation angle of the rotor detected by the sensors 41u, 41v, and 41w at the timing of the switching of the output signal of the Hall IC, an error of 0° to 60° occurs between the rotation angle of the rotor detected by the sensors 41u, 41v, and 41w and the actual rotation angle of the rotor in the motor 40. Hereinafter, such an arrangement of the Hall ICs is referred to as arrangement B.

[0041] FIG. 4 is a plot showing an example of the relationship between the rotor rotation angle of the actual motor 40 and the motor torque (proportion to maximum torque) in a range where the rotor rotation angle detected by the sensors 41u, 41v, and 41w is constant (a range where the rotation angle detection signals Hu, Hv, and Hw are constant). As can be seen from FIG. 4, in the case of arrangement B, the motor torque fluctuates greatly, for example, between about 50% and 100%, due to the rotation of the rotor. Such fluctuations in the motor torque cause torque ripple. As a means for reducing torque ripple, it is known to arrange three Hall ICs at a distance of 30° from arrangement B. Hereinafter, such an arrangement of the Hall ICs is referred to as arrangement A. In the case of arrangement A, the error between the rotor rotation angle detected by the sensors 41u, 41v, and 41w and the rotor rotation angle of the actual motor 40 is within a range of -30° to 30°. As can be seen from FIG. 4, in the case of arrangement A, the torque fluctuation falls within a range of, for example, about 87% to 100%, and is significantly suppressed compared to the case of arrangement B.

[0042] However, even in the case of arrangement A, the motor torque decreases by, for example, up to about 13% depending on the rotation angle of the rotor. Therefore, for example, if the motor is used in a motor drive unit of an electrically assisted bicycle, depending on the rotation angle of the rotor, excessive current may flow in the circuit to output a certain torque at startup under high load (for example, when starting to pedal), causing the overcurrent protection function to activate and resulting in a torque shortage, or the excessive current may reduce control responsiveness and cause sudden torque fluctuations, raising concerns about a decrease in the riding comfort of the electrically assisted bicycle.

[0043] On the other hand, in the rotating device 100 according to this embodiment, the motor 40 rotates in the second direction R2, which is a reverse rotation, at start-up before starting to rotate in the first direction R1, which is a forward rotation. This allows the rotation angle of the rotor to be moved to a rotation angle at which the torque of the motor 40 is a maximum value or a local maximum value (or a value close to these). At that time, the load when rotating the motor 40 in the reverse direction is kept to a minimum by the action of the first one-way clutch 31, and the reverse rotation of the motor 40 does not affect the third shaft 23 (crankshaft). Therefore, according to the rotating device 100 according to this embodiment, the torque at the time of high load start-up can be improved while minimizing the influence on others.

[0044] In the rotating device 100 according to this embodiment, the rotation angle of the motor 40 when the first signal Sa is inputted to rotate in the second direction R2 is smaller than 360°. Therefore, the time required for reverse rotation can be reduced, and even when the rotating device 100 is a part of a motor drive unit of an electric-assisted bicycle, for example, the rider does not feel uncomfortable due to a time lag when starting to pedal. The rotation angle of the motor 40 when the first signal Sa is inputted to rotate in the second direction and stop can be set to 180° or less, 120° or less, or 60° or less depending on the configuration of the motor 40 (for example, the number of slots of the stator, the number of magnetic poles of the rotor, etc.). The smaller the rotation angle of the motor 40 when the first signal Sa is inputted to rotate in the second direction and stop, the shorter the time required for reverse rotation can be.

[0045] Although the rotating device of the present invention has been described above with reference to preferred embodiments, the rotating device of the present invention is not limited to the configuration of the above embodiments. For example, in the above embodiments, the rotating device 100 includes six gears, namely, the first gear 11, the second gear 12, the third gear 13, the fourth gear 14, the fifth gear 15, and the output gear 16, but the number of gears in the rotating device of the present invention is not limited, and may be one, two, three, four, five, or seven or more.

[0046] In the above embodiment, the rotating device 100 has three shafts: the first shaft 21, the second shaft 22, and the third shaft 23. However, in the rotating device of the present invention, the number of shafts is not limited and may be one, two, four or more.

[0047] In the above embodiment, the rotating device 100 includes three one-way clutches, namely, the first one-way clutch 31, the second one-way clutch 32, and the third one-way clutch 33, but in the rotating device of the present invention, the number of one-way clutches is not limited and may be one, two, four or more. Also, in the rotating device of the present invention, the one-way clutches do not need to be fixed to the inner circumferential surface of the gear.

[0048] In the above embodiment, the rotation direction of motor 40 is defined as forward rotation when it is in the first direction R1, and as reverse rotation when it is in the second direction R2. However, depending on the application, the rotation direction of motor 40 may be defined as reverse rotation when it is in the first direction R1, and may be defined as forward rotation when it is in the second direction R2.

[0049] 1, the motor drive control device 50 is accommodated inside the housing 60, but in the rotating device of the present invention, a part or the whole of the motor drive control device may be disposed outside the housing. Also, the rotating device of the present invention does not have to have a housing.

[0050] In the above embodiment, motor 40 includes three Hall ICs (sensors 41u, 41v, 41w), but the number of Hall ICs is not limited to three. Furthermore, the Hall ICs do not have to be arranged at equal angular intervals from each other. The rotating device of the present invention may include a sensor other than a Hall IC. The rotating device of the present invention may not have a sensor.

[0051] When the rotating device of the present invention includes a plurality of Hall ICs as sensors, each Hall IC may be arranged so that the rotor rotation angle coincides with the rotor rotation angle detected by the sensor at the timing when the output signal of the Hall IC is switched, or may be arranged so that the rotor rotation angle coincides with the timing when the rotor rotation angle becomes 30° (or −30°), or may be arranged so that the rotor rotation angle coincides with the timing when the rotor rotation angle becomes another angle. The method of determining in step S4 that the rotor has reached a predetermined rotation angle may be changed to any method depending on the presence or absence of a sensor and its arrangement.

[0052] In the above embodiment, the rotating device 100 has been described assuming its use in a motor drive unit of an electrically assisted bicycle, but the rotating device of the present invention may be used for other purposes.

[0053] 5 shows a rotating device 200 as a modified example of the above embodiment. For convenience, the components of the rotating device 200 will be described below using the same names and symbols as the corresponding components of the rotating device 100. The names of the components include "first," "third," and the like, and are used to clarify the correspondence with the components of the rotating device 100, and do not necessarily indicate that the rotating device 200 has a specific number of components.

[0054] The rotating device 200 includes an output gear 16 that constitutes a part of the output shaft, a third shaft 23 that constitutes another part of the output shaft, a first one-way clutch 31, a third one-way clutch 33, a motor 40, a motor drive control device 50 as a control device, and a housing 60. The motor 40 includes a cylindrical shaft S. The third shaft 23 is disposed inside the shaft S of the motor 40. The shaft S and the third shaft 23 are rotatable relative to each other around the extension direction. Outside the housing 60, a chain ring 70 is fixed to the output gear 16. Note that descriptions that overlap with the above embodiment will be omitted.

[0055] In the rotating device 200 in the modified example, the motor 40 is connected to the third shaft 23 constituting the output shaft via the first one-way clutch 31 or the third one-way clutch 33. Specifically, inside the housing 60, the output gear 16 is fixed to the shaft S of the motor 40 via the first one-way clutch 31. The inner circumferential surface of the output gear 16 (the circumferential surface on the side closer to the shaft S of the motor 40) is fixed to the outer circumferential surface of the first one-way clutch 31 (the circumferential surface on the side farther from the shaft S of the motor 40). Also, the inner circumferential surface of the first one-way clutch 31 (the circumferential surface on the side closer to the shaft S of the motor 40) is fixed to the outer circumferential surface of the shaft S of the motor 40.

[0056] Inside the housing 60, the output gear 16 is fixed to the third shaft 23 via the third one-way clutch 33. The inner circumferential surface of the output gear 16 (the circumferential surface on the side closer to the third shaft 23) is fixed to the outer circumferential surface of the third one-way clutch 33 (the circumferential surface on the side farther from the third shaft 23). Also, the inner circumferential surface of the third one-way clutch 33 (the circumferential surface on the side closer to the third shaft 23) is fixed to the outer circumferential surface of the third shaft 23. As described above, the rotating device of the present invention may be configured such that the motor is directly connected to the output shaft via the one-way clutch.

[0057] In addition, a person skilled in the art can appropriately modify the rotating device of the present invention and change the shapes, dimensions, and combinations of various components in accordance with conventional knowledge. As long as the configuration of the present invention is still provided even after such modifications, it is of course included in the scope of the present invention. [Explanation of symbols]

[0058] 12...gear (second gear), 16...output gear (output shaft), 23...shaft (third shaft (output shaft)), 31...one-way clutch (first one-way clutch), 40...motor, 41u, 41v, 41w...sensor, 50...control device (motor drive control device), 100...rotating device, R1...first direction, R2...second direction, Sa...first signal, Sb...second signal.

Claims

1. An output shaft; A one-way clutch, a motor directly or indirectly connected to the output shaft via the one-way clutch; a control device; Equipped with the motor is rotatable in a first direction and a second direction opposite to the first direction; the one-way clutch transmits rotation of the motor in a first direction; the control device outputs a first signal, and after outputting the first signal, outputs a second signal; The motor rotates in the second direction when the first signal is input. The rotating device, wherein the motor rotates in the first direction when the second signal is input.

2. a shaft serving as the output shaft; Gear and, The rotating device according to claim 1 , wherein the motor is coupled to the output shaft via the gear.

3. The rotating device according to claim 1 , wherein the motor rotates in the second direction by an angle smaller than 360° when the first signal is input.

4. Equipped with a sensor, The rotating device according to claim 1 , wherein the sensor detects a rotation angle of the motor.

5. The rotating device according to claim 4 , wherein a rotation angle at which the torque of the motor shows a maximum value exists within a range of rotation angles of the motor that can be detected by the sensor.

Images