Traveling unit and traveling vehicle

Abstract

In order to achieve improvement in running stability and operability, improvement in freedom of design layout, ease of assembly and adjustment, and compliance with the riding feeling of the user with a simple configuration, on a running unit (140), a neutral restoration mechanism (160L, 160R) is provided which supports a pair of left and right wheels (155L, 155R) by upper and lower moving swing arms (151L, 151R) in a staggered linkage and has an extension member (165L, 165R) that extends and contracts in accordance with the swing of the swing arms (151L, 151R), the neutral restoration mechanism (160L, 160R) being configured so that the torque acting on the swing arms (151L, 151R) by the restoration force of the extension member (165L, 165R) is substantially constant and independent of the amount of swing of the swing arms (151L, 151R). The running vehicle is provided with the above-described running unit (140).

Description

Technical Field

[0001] The present invention relates, for example, to a driving unit and a vehicle having the driving unit, the driving unit having a pair of left and right wheels, the pair of left and right wheels being supported so as to be able to swing about a swing center axis extending in the horizontal direction, and to move up and down in an alternating manner. Background Technology

[0002] For example, as a vehicle with a pair of left and right wheels provided on at least one of the front or rear wheels, there is a known vehicle with a buffer mechanism that independently suspends the left and right wheels. The buffer mechanism is configured to support the left and right pairs of wheels so that they can swing in the vertical direction, and the vertical movement of the wheels is staggered and linked, thereby absorbing the impact during driving and generating a reaction force (restoring force) that restores the wheels to the neutral position.

[0003] Patent Document 1 describes a configuration in which left and right auxiliary arms, each supporting a pair of auxiliary wheels, are connected to a balance arm via springs. The balance arm is supported on the vehicle frame in a manner that allows it to rotate freely in the left-right direction relative to the vehicle body. Furthermore, each auxiliary arm is connected to a bracket fixed to the vehicle frame via a shock absorber. This configuration generates approximately equal elastic forces on each auxiliary wheel to achieve stable driving, and the synergistic effect of the springs and shock absorbers suppresses swaying during driving.

[0004] Furthermore, as shown in Patent Document 2, as a system that causes the up and down movement of a pair of wheels to be interleaved, there is a known configuration that controls the hydraulic cylinder with hydraulic pressure.

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-248696

[0007] Patent Document 2: Japanese Patent Application Publication No. 2019-209809 Summary of the Invention

[0008] Furthermore, in a configuration like Patent Document 1 described above, where a spring component serves as a buffer mechanism, the reaction force of the spring component increases monotonically in proportion to the increase in the swing of the arm component supporting the wheel. Therefore, the reaction force of the spring component affects the swing stiffness. Consequently, while stability can be improved when the extension / retraction direction of the spring component is aligned with the tangent to the circle centered on the swing axis of the arm component, or when it is tilted at a certain angle to the extension direction of the arm component, it may hinder the smooth swing of the swing component, for example, when driving on an incline or turning, thereby reducing driving stability and maneuverability.

[0009] In addition, there is a situation where, due to the linkage and swinging of each arm component, the spring components installed on each arm component interfere with each other, resulting in the inability to obtain the appropriate reaction force of the spring components.

[0010] Furthermore, the linkage mechanism described in Patent Document 1 suffers from a reduction in the degree of freedom in the device layout, while the linkage mechanism described in Patent Document 2 suffers from a complex structure and increased manufacturing costs.

[0011] The present invention is based on the above situation. The technical problem to be solved is to provide a riding unit and a riding vehicle equipped with such a riding unit that can improve riding stability and operability with a simple structure, have a high degree of freedom in design layout, are easy to assemble and adjust, and can realize a riding feel that conforms to the user.

[0012] This invention relates to a driving unit comprising: a pair of left and right wheels; a left wheel support mechanism that pivotally supports the left wheel about a pivot axis extending in the left-right direction; a right wheel support mechanism that pivotally supports the right wheel about the pivot axis; a frame unit that supports the left and right wheel support mechanisms; and a linkage mechanism that is linked to the pivoting of one wheel, causing the other wheel to pivot in the opposite direction to the first wheel. The problem can be solved by the following: each of the left and right wheel support mechanisms comprises: a swing arm, one end of which is connected to the wheel axle, and the other end of which is connected to the frame unit, allowing it to pivot about the pivot axis; and a neutralization recovery mechanism that returns the swing arm to a neutral state. The neutralization recovery mechanism includes a telescopic member that extends and retracts according to the pivoting of the swing arm, and is configured such that the torque acting on the swing arm by the recovery force of the telescopic member is substantially constant and independent of the amount of pivoting of the swing arm.

[0013] According to the present invention, the driving unit and the vehicle equipped with the driving unit can substantially equalize the ground pressure of each wheel by linking the up-and-down movement of a pair of wheels. Furthermore, by configuring the neutralization recovery mechanism such that the torque acting on the swing arm by the telescopic member is substantially constant regardless of the swing arm's swing amount, the telescopic member does not impede the swing arm's swing and can generate the torque required to restore the swing arm to the neutral position. Therefore, for example, when driving on an incline or turning, it can tilt along with the vehicle body, thereby improving driving stability and maneuverability with a simple configuration and reducing the risk of rollover.

[0014] Furthermore, since the neutral recovery mechanism can be configured within the space of the swing arms in the left and right directions, it allows for compactness and increases the flexibility of design layout. Thus, for example, the cargo box can be positioned between the wheels, effectively utilizing the space between a pair of wheels.

[0015] Furthermore, since the riding feel or passenger comfort of the vehicle can be easily altered by appropriately replacing the telescopic components, it is possible to achieve a riding feel that meets the user's needs or preferences.

[0016] Furthermore, by configuring the telescopic component to extend in a direction substantially parallel to the extension direction of the swing arm, the adverse effects on the vehicle's rotation or stability when driving on inclined surfaces caused by the restoring force of the telescopic component can be further and more effectively reduced, thereby improving driving stability and handling.

[0017] Furthermore, by configuring an obstacle avoidance mechanism that allows displacement of the first or second fulcrum of the telescopic member, the telescopic members on the left wheel support mechanism and the right wheel support mechanism will not interfere with each other, allowing each neutral return mechanism to operate independently. Therefore, the torque required to return the swing arm to the neutral position can be reliably obtained through the neutral return mechanism, and a spring component with a small spring constant can be used as the telescopic member.

[0018] Furthermore, because there are fewer parts and the main parts can be placed in easily accessible locations on the outside of the vehicle, assembly or adjustment is convenient.

[0019] Furthermore, by configuring one end or the other end of the telescopic member to be movably hinged within the opening constituting the avoidance mechanism, stability can be improved with a simple and cost-effective configuration.

[0020] Furthermore, because the linkage mechanism is configured such that rotational transmission occurs between the first and second swinging rotating bodies, which rotate in conjunction with the swing arm, and the first and second transmission rotating bodies, which are connected to the same rotation axis and can rotate integrally, the first and second transmission bars are configured such that the rotation directions of the first and second swinging rotating bodies are opposite to each other. This ensures that the vertical movement of the left and right wheels is reliably linked. Therefore, regardless of road conditions or driving status, the ground pressure on the left and right wheels can be evenly distributed, resulting in higher driving stability and better maneuverability. Attached Figure Description

[0021] Figure 1 This is a perspective view showing the configuration of an example of a vehicle involved in the present invention.

[0022] Figure 2 It indicates composition Figure 1 The diagram shows a three-dimensional view of the composition of the driving unit of the rear wheel unit on a moving vehicle.

[0023] Figure 3 yes Figure 2 The left-side view of the driving unit shown.

[0024] Figure 4 yes Figure 2 The right-side view of the driving unit shown.

[0025] Figure 5 It means Figure 2 A top view of the configuration of the left wheel support mechanism on the driving unit shown.

[0026] Figure 6 It is a graph showing the relationship between the swing arm's swing amount and swing stiffness.

[0027] Figure 7 It means Figure 2 A top view of the right wheel support mechanism on the driving unit shown.

[0028] Figure 8 It means Figure 2 A top view showing the configuration of the linkage mechanism on the driving unit.

[0029] Figure 9 yes Figure 8 Sectional view along line AA in the diagram.

[0030] Figure 10 yes Figure 8 BB line section view.

[0031] Figure 11 It means to make Figure 1 The rear view shown is of a vehicle tilting as it makes a left turn on a flat road.

[0032] Figure 12A This is a left-side view of the driving unit, viewed from the axle direction of the left-side wheel.

[0033] Figure 12B This is a right-side view of the driving unit, viewed from the axle direction of the right-side wheel.

[0034] Figure 13 This is a right-side view schematically illustrating the configuration of another example of the driving unit involved in the present invention.

[0035] Figure 14A This is a right-side view of the driving unit, viewed from the axle direction of the right wheel, when the right-side swing arm swings upward.

[0036] Figure 14B This is a right-side view of the driving unit, viewed from the axle direction of the right wheel, when the right-side swing arm swings downwards.

[0037] Symbol Explanation

[0038] 100 - Tricycle; 110 - Frame; 111 - Frame; 111a - Main frame; 111b - Downtube; 111c - Headtube; 111d - Seatpost; 115 - Drive unit; 116 - Drive unit; 117a - Crankshaft; 117b - Crank arm; 117c - Pedals; 120 - Steering unit; 121 - Handlebar stem; 122 - Handlebar; 125 - Seat; 126 - Seatpost; 12 7-Saddle; 130-Front wheel unit; 131-Front fork; 132-Front wheel; 133-Axle; 140-Rear wheel unit (running unit); 141-Frame unit; 142L, 142R-Side plates; 143-Load-bearing chassis support plate; 144-Load-bearing chassis; 145-Pivot bracket; 146-Avoiding mechanism; 147-Opening; 148-Positioning plate; 149-Limiting component; 150L-Left Side wheel support mechanism; 150R - Right side wheel support mechanism; 151L, 151R - Swing arm; 152a, 152b - Bushing part; 153 - Sleeve component; 154 - Bearing; 155L, 155R - Wheel; 156L, 156R - Axle; 160L, 160R - Neutralization mechanism; 161 - Support plate; 162 - Support part; 165L, 165R - Telescopic component; 166 - Shaft component; 170 - Linkage mechanism; 171L, 171R - Swing shaft; 172 - Sleeve component; 173 - Bearing; 175 - Linkage shaft; 176L - First swing sprocket; 176R - Second swing sprocket; 177L - First transmission sprocket; 177R - Second transmission sprocket; 178L - First transmission belt; 178R - Second transmission belt; Sa - Swing center axis; Ra - Rotation center axis. Detailed Implementation

[0039] The invention will now be described using a three-wheeled bicycle with two independent suspension wheels on the rear side as an example, but the direction will be defined based on the line of sight of the user traveling straight on the three-wheeled bicycle.

[0040] like Figure 1 As shown, the tricycle 100 according to this embodiment includes: a frame 110; a front wheel unit 130 having a front wheel 132 as a steering wheel; and a rear wheel unit 140 having a pair of left and right wheels as drive wheels.

[0041] The body section 110 includes: a body frame 111; a drive section 115 that transmits the pedal force generated by the user pressing the pedal 117c and the rotational force generated by the drive unit 116 that assists the pedal force to each wheel of the rear wheel unit 140 as driving force; a steering section 120 that steers the front wheel 132; and a seating section 125 that allows the human body to sit.

[0042] The vehicle frame 111 includes: a main frame 111a, forming a space for accommodating the drive unit 116; a lower tube 111b, extending forward and upward from the front of the main frame 111a; a head tube 111c, disposed at the front end of the lower tube 111b and extending in the vertical direction; and a seat tube 111d, disposed on the central part of the main frame 111a and extending upward.

[0043] The drive unit 115 includes: a drive unit (including an electric motor) 116; a crankshaft 117a rotatably mounted on the drive unit 116 extending in a left-right direction; crank arms 117b mounted at both ends of the crankshaft 117a; pedals 117c mounted at the top of the crank arms 117b; and a power transmission mechanism using a chain or belt as the transmission component. Although for ease of understanding... Figure 1 Not shown, but the power transmission mechanism includes: a drive sprocket, which is coaxially arranged with the crankshaft 117a and rotates together with the crankshaft 117a; a driven sprocket, which rotates together with the wheel of the rear wheel unit 140; and a transmission component, which is wound between the drive sprocket and the driven sprocket.

[0044] The steering unit 120 includes: a handlebar stem 121, which is rotatably inserted into the head tube 111c; and a handlebar 122, which is fixed to the upper end of the handlebar stem 121.

[0045] The seating portion 125 includes: a seat post 126 inserted into a seat tube 111d; and a saddle 127 mounted on the upper end of the seat post 126.

[0046] The front wheel unit 130 has a front fork 131 fixed to the lower end of the handlebar stem 121, and a front wheel 132 is rotatably supported on the lower end of the front fork 131 via an axle 133.

[0047] like Figures 2 to 4As shown, the rear wheel unit 140 is composed of a driving unit, which includes: a left wheel 155L, which is the left rear wheel, and a right wheel 155R, which is the right rear wheel; a left wheel support mechanism 150L, ​​which swings and supports the left wheel 155L around a swing center axis Sa extending in the left and right directions, and a right wheel support mechanism 150R, which swings and supports the right wheel 155R around the same swing center axis Sa as the left wheel support mechanism 150L; a frame unit 141, which supports the left wheel support mechanism 150L and the right wheel support mechanism 150R; and a linkage mechanism 170, which is linked to the swing of one wheel, so that the other wheel swings in the opposite direction to the first wheel.

[0048] The frame unit 141 includes: a pair of side plates 142L, 142R, which are opposite each other in the left-right direction and extend in the front-back direction; flat load-bearing chassis support plates 143, 143, which are arranged to extend in the front-back direction on the upper part of the outer side of each side plate 142L, 142R; a load-bearing chassis 144, which is fixed on the upper part of the load-bearing chassis support plates 143, 143; and fulcrum brackets 145, 145, which serve as support parts, are fixed on the two side edges on the lower part of the load-bearing chassis 144 to support one end of the telescopic members 165L, 165R described later.

[0049] In this embodiment, the pivot bracket 145 is fixed to the load-bearing chassis 144 by screws. Screw insertion holes are formed on the load-bearing chassis 144 at predetermined intervals in the front-rear direction. Therefore, the fixed position of the pivot bracket 145 relative to the load-bearing chassis 144 can be adjusted in the front-rear direction, increasing the selectivity of the telescopic components 165L and 165R, and facilitating adjustments to the riding or passenger comfort of the tricycle 100.

[0050] like Figure 5 As shown, the left wheel support mechanism 150L includes: a rod-shaped swing arm 151L, with bushing portions 152a and 152b extending in the left and right directions at both ends; and a neutralization restoration mechanism 160L, which restores the swing arm 151L to a neutral state.

[0051] In the bushing portion 152a at one end of the swing arm 151L, a swing shaft 171L is fitted in such a way that it is coaxial with the swing center axis Sa (see reference). Figure 10 The swing shaft 171L is rotatably supported in the sleeve component 153 mounted on the side plate 142L by the bearing 154. Thus, the wheel 155L, whose axle 156L is rotatably supported by the bushing portion 152b on the other end of the swing arm 151L, is supported so that it can swing about the swing center axis Sa.

[0052] The neutral recovery mechanism 160L includes a telescopic member 165L that extends and retracts according to the swing of the swing arm 151L. In this embodiment, the telescopic member 165L is, for example, a tension spring.

[0053] One end of the telescopic component 165L is connected to the support bracket 145 of the frame unit 141. The connection point between one end of the telescopic component 165L and the frame unit 141, i.e., the first support point, is located near the swing center axis Sa of the swing arm 151L (see reference). Figure 3 ).

[0054] The other end of the telescopic component 165L is fixed to the support plate 161, which is provided on the swing arm 151L as a support.

[0055] Thus, in this embodiment, the telescopic member 165L is configured to be substantially parallel to the extending direction of the swing arm 151L, and the telescopic member 165L extends and retracts in a direction different from the swing direction of the swing arm 151L. Here, "substantially parallel" means not only that the two are completely parallel, but also that even if there is a slight inclination, they are substantially parallel.

[0056] By configuring the telescopic component 165L in this way, such as Figure 6 As shown, the change in swing stiffness relative to the change in the swing amount of the swing arm 151L can be reduced. Specifically, when the swing arm 151L swings in the direction of extension (downward) of the telescopic member 165L, as the swing amount of the swing arm 151L increases, the restoring force of the telescopic member 165L increases, but the angle between the swing arm 151L and the telescopic member 165L decreases. Therefore, the neutral restoring mechanism 160L can be configured such that the torque acting on the swing arm 151L by the restoring force of the telescopic member 165L is substantially constant regardless of the swing amount of the swing arm 151L. Therefore, the torque required to restore the swing arm 151L to the neutral position by the neutral restoring mechanism 160L can be set to an appropriate size that does not hinder cornering, and for example, the handling can be improved when driving on an incline.

[0057] Here, "substantially constant" means that the rate of change of torque acting on the swing arm 151L within the swing range of the swing arm 151L (Tmax-Tmin) / ((Tmax+Tmin) / 2) is within 30%.

[0058] like Figure 7 As shown, the right wheel support mechanism 150R has the same structure as the left wheel support mechanism 150L, ​​and includes: a rod-shaped swing arm 151R, with bushing portions 152a and 152b extending in the left and right directions at both ends; and a neutral restoration mechanism 160R, which restores the swing arm 151R to a neutral state.

[0059] In the bushing portion 152a at one end of the swing arm 151R, a swing shaft 171R is fitted in such a way that it is coaxial with the swing center axis Sa (see reference). Figure 10 The swing shaft 171R is rotatably supported in the sleeve component 153 mounted on the side plate 142R by the bearing 154. Thus, the wheel 155R, whose axle 156R is rotatably supported by the bushing portion 152b on the other end of the swing arm 151R, is supported so that it can swing about the swing center axis Sa.

[0060] The neutral recovery mechanism 160R includes a telescopic member 165R that extends and retracts according to the swing of the swing arm 151R. In this embodiment, the telescopic member 165R is, for example, a tension spring.

[0061] One end of the telescopic component 165R is connected to the support bracket 145 of the frame unit 141. The connection point between one end of the telescopic component 165R and the frame unit 141, i.e., the first support point, is located near the swing center axis Sa of the swing arm 151R (see reference). Figure 4 ).

[0062] The other end of the telescopic component 165R is fixed to the support plate 161 provided on the swing arm 151R.

[0063] Thus, in this embodiment, the telescopic member 165R is configured to extend in a direction substantially parallel to the extension direction of the swing arm 151R, and the telescopic member 165R extends and retracts in a direction different from the swing direction of the swing arm 151R. Therefore, the change in swing stiffness relative to the change in the amount of swing of the swing arm 151R can be reduced; in other words, the torque acting on the swing arm 151R by the restoring force of the telescopic member 165R can be made substantially constant regardless of the amount of swing of the swing arm 151R. Consequently, the torque required to restore the swing arm 151R to the neutral position via the neutral restoring mechanism 160R can be set to an appropriate magnitude that does not hinder cornering, and for example, handling during driving on inclined surfaces can be improved.

[0064] like Figure 3 and Figure 4As shown, the tricycle 100 according to this embodiment is provided with a collision avoidance mechanism 146. This collision avoidance mechanism 146 is configured such that when a torque is applied to the swing arm through the telescopic member in one of the neutral recovery mechanisms, one end of the telescopic member can be displaced at the connection point with the frame unit 141, i.e., the first fulcrum, so that the torque is not applied to the swing arm through the telescopic member in the other neutral recovery mechanism. The collision avoidance mechanism 146 has the same configuration in the left and right neutral recovery mechanisms 160L and 160R. Hereinafter, the configuration of the collision avoidance mechanism 146 in the neutral recovery mechanism 160L of the left wheel 155L will be specifically described, and the description of the collision avoidance mechanism 146 in the neutral recovery mechanism 160R of the right wheel 155R will be omitted.

[0065] like Figure 3 As shown, a shaft member 166 is provided at one end of the telescopic member 165L. By inserting the shaft member 166 into the openings 147 formed on the side walls of the fulcrum bracket 145, which has a cross-section of half-I-shape, one end of the telescopic member 165L can be hinged to the fulcrum bracket 145 in a manner that allows it to move within the openings 147. In this embodiment, the openings 147 are formed by an elongated hole that extends obliquely upwards and forwards, and the arcuate portion of the elongated hole has a diameter larger than that of the shaft member 166. Furthermore, a positioning plate (dogplate) 148 extending along the swing arm 151L is fixed to the support plate 161. By swinging the swing arm 151L upwards, the positioning plate 148 presses down on the shaft member 166, allowing the first fulcrum of the telescopic member 165L to move within the openings 147 without contacting the inner surface of the openings 147.

[0066] Since the left and right neutral restoration mechanisms 160L and 160R are each equipped with an obstacle avoidance mechanism 146, each neutral restoration mechanism 160L and 160R can work independently.

[0067] like Figures 8 to 10 As shown, the linkage mechanism 170 includes: a first oscillating rotating body, namely a first oscillating sprocket 176L, which is disposed on the left oscillating shaft 171L; a second oscillating rotating body, namely a second oscillating sprocket 176R, which is disposed on the right oscillating shaft 171R; a linkage shaft 175, which is configured to extend in the left-right direction on a rotation center axis Ra that extends parallel to the oscillating center axis Sa; a first transmission rotating body, namely a first transmission sprocket 177L and a second transmission rotating body, namely a second transmission sprocket 177R, which are disposed on the linkage shaft 175; a first transmission bar, namely a first transmission belt 178L, which transmits rotation between the first oscillating sprocket 176L and the first transmission sprocket 177L; and a second transmission bar, namely a second transmission belt 178R, which transmits rotation between the second oscillating sprocket 176R and the second transmission sprocket 177R.

[0068] The linkage shaft 175 is rotatably supported by bearings 173 in sleeve components 172, 172 mounted on the respective side plates 142R, 142L, in a manner coaxial with the rotation center axis Ra.

[0069] In this embodiment, the first drive belt 178L and the second drive belt 178R are toothed drive belts (synchronous belts) with ends. The first drive belt 178L is cross-wound with respect to the first oscillating sprocket 176L and the first transmission sprocket 177L, and the second drive belt 178R is wound parallel to the second oscillating sprocket 176R and the second transmission sprocket 177R. Thus, the first oscillating sprocket 176L and the second oscillating sprocket 176R can be linked together in a manner where their rotation directions are opposite to each other.

[0070] Furthermore, on the tricycle 100 involved in this embodiment, for example, Figure 11 As shown, when the tricycle 100 is making a left turn on a flat road surface Sr, the left swing arm 151L swings upward around the swing center axis Sa as the user leans their body along with the vehicle. Figure 12A As shown, with the swing of the left swing arm 151L, the left swing shaft 171L rotates, thereby rotating the first swing sprocket 176L, and transmitting power to the first transmission sprocket 177L via the first transmission belt 178L. Then, as... Figure 12B As shown, the first transmission sprocket 177L rotates, causing the linkage shaft 175 to rotate, which in turn causes the second transmission sprocket 177R to rotate, transmitting power to the second oscillating sprocket 176R via the second transmission belt 178R. This causes the right-side oscillating shaft 171R to rotate, and the right-side swing arm 151R to swing downwards around the oscillation center axis Sa. Therefore, even when the vehicle is tilted, the ground pressure of the left wheel 155L and the right wheel 155R can be evenly distributed, ensuring smooth rotation and driving stability while providing a smooth riding or gliding experience similar to that of a two-wheeled vehicle.

[0071] Furthermore, the positioning plate 148 on the left side presses down on the axle member 166 in conjunction with the swing of the left swing arm 151L, causing the axle member 166 to move within the opening 147 of the fulcrum bracket 145. Due to the displacement of the first fulcrum of the left telescopic member 165L, the restoring force of the left telescopic member 165L remains inactive as it maintains its natural state. On the other hand, since the axle member 166 involved in the right telescopic member 165R engages with the opening 147 of the fulcrum bracket 145, the right telescopic member 165R does not extend due to the influence of the left telescopic member 165L when the right swing arm 151R swings. Therefore, when the tricycle 100 resumes straight-line travel, an appropriate torque is applied to restore the right swing arm 151R to a neutral position, thereby enabling the tilted vehicle body to reliably and easily return to a neutral (vertical) state.

[0072] The above describes the operation of the linkage mechanism 170 and the left and right neutral recovery mechanisms 160L and 160R when the tricycle 100 makes a left turn. However, when making a right turn, when entering a slope from a flat road surface, or when passing obstacles such as steps, the linkage mechanism 170 and the left and right neutral recovery mechanisms 160L and 160R will also perform the same operation.

[0073] While the above embodiments are configured such that the first fulcrum of the telescopic member is configured as a displaceable obstacle avoidance mechanism, they can also be configured such that the second fulcrum of the telescopic member is configured as a displaceable obstacle avoidance mechanism.

[0074] Figure 13 This is a right-side view schematically illustrating the configuration of another example of the driving unit involved in the present invention.

[0075] In the driving unit involved in this embodiment, the left wheel support mechanism and the right wheel support mechanism also have the same configuration. Hereinafter, the configuration of the right wheel support mechanism will be described and the description of the left wheel support mechanism will be omitted.

[0076] The swing arm 151R in the driving unit has a plate-shaped support portion 162, which is extended into a bushing portion on the other end side of the axle 156R that rotatably supports the wheel 155R, and supports the other end of the telescopic member 165R.

[0077] One end of the telescopic member 165R is fixed to the frame unit 141 such that the connection point between one end of the telescopic member 165R and the frame unit 141, i.e. the first fulcrum, is located near the swing center axis Sa of the swing arm 151R.

[0078] A shaft member 166 is provided at the other end of the telescopic member 165R. By inserting the shaft member 166 into the opening 147 formed on the support portion 162 of the swing arm 151R, the other end of the telescopic member 165R is hinged to the support portion 162 in a manner that allows it to move within the opening 147. Thus, an avoidance mechanism 146 can be constructed, which is configured to displace the connection point between the other end of the telescopic member 165R and the swing arm 151R, i.e., the second fulcrum.

[0079] In this embodiment, the opening 147 is, for example, formed by an elongated hole extending along the swing direction of the swing arm 151R, the arcuate portion of which has a diameter larger than that of the shaft member 166.

[0080] In the driving unit of this embodiment, when in a neutral state, the shaft member 166 is in a state of contact with the limiting member 149 provided on the frame unit 141 and engaged with the upper side of the opening 147 on the support 162.

[0081] When the swing arm 151R swings upward, then as Figure 14A As shown, the shaft component 166 moves within the opening 147 of the support portion 162. Due to the displacement of the second fulcrum of the telescopic component 165R, the telescopic component 165R maintains its natural state, and therefore no restoring force caused by the telescopic component 165R is applied.

[0082] On the other hand, when the swing arm 151R swings downwards, then as Figure 14B As shown, since the shaft component 166 engages with the opening 147 of the support portion 162, the telescopic component 165R will extend due to the swing of the swing arm 151R.

[0083] Since the vertical movement of the swing arm 151R and the other swing arm (not shown) are interleaved, the telescopic components of one side and the telescopic components of the other side will not interfere with each other in this travel unit, thereby enabling the neutral recovery mechanism to work independently.

[0084] While the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments. Various design changes can be made without departing from the scope of the present invention as defined in the claims.

[0085] For example, the travel unit involved in this invention can also be configured such that a constant load spring is used to construct the telescopic component, so that the torque acting on the swing arm is substantially constant regardless of the amount of swing of the swing arm.

[0086] Furthermore, the support structure at one end of the telescopic component is not limited to a pivot bracket hinged to a load-bearing chassis. For example, a support portion can be formed on the bushing portion at one end of the swing arm, and one end of the telescopic component can be hinged.

[0087] Furthermore, although the above embodiment uses an elongated hole to construct the avoidance mechanism, any opening with the following configuration is acceptable: that is, when the swing arm swings in the extension direction of the telescopic member, it can engage with the shaft member, and when the swing arm swings in the retraction direction of the telescopic member, it can allow the shaft member to move.

[0088] Furthermore, the driving unit involved in this invention can be used in various vehicles that can move on wheels, such as vehicles equipped with engines, electric motors, etc., bicycles driven by human power, and trolleys for transporting goods.

[0089] Furthermore, although the above embodiment describes the case where the wheels of the driving unit function as the rear wheels of a driving vehicle, the configuration of the driving unit is not limited to this. For example, it can also be installed to function as the front wheels of a driving vehicle.

[0090] Furthermore, although the transmission strip is constructed using an end-shaped synchronous belt in the above embodiment, the transmission strip can also be a linear body such as a chain or rope. Additionally, the parallel-coiled second transmission strip can be endless. When the first and second transmission strips are constructed with ends, each oscillating rotating body and each transmission rotating body only needs to have the end of its respective transmission strip fixed and be able to transmit force in the tensile direction; some or all of the teeth on the outer periphery can also be eliminated.

Claims

1. A driving unit comprising: a pair of left and right wheels; a left wheel support mechanism oscillatingly supporting the left wheel about a swing center axis extending in the left-right direction; a right wheel support mechanism oscillatingly supporting the right wheel about the swing center axis; a frame unit supporting the left wheel support mechanism and the right wheel support mechanism; and a linkage mechanism that is linked to the swing of one wheel, causing the other wheel to swing in the opposite direction to the first wheel, characterized in that... Each of the left and right wheel support mechanisms includes: a swing arm, one end of which is connected to the wheel axle and the other end of which is connected to the frame unit, capable of swinging about the swing center axis; and a neutralization restoration mechanism to restore the swing arm to a neutral state. The neutral restoring mechanism includes a telescopic member that extends and retracts according to the swing of the swing arm, and is configured such that the torque acting on the swing arm by the restoring force of the telescopic member is substantially constant and independent of the amount of swing of the swing arm.

2. The driving unit according to claim 1, characterized in that, The telescopic component is configured to extend in a direction substantially parallel to the extension direction of the swing arm.

3. The driving unit according to claim 1, characterized in that, The telescopic component is configured such that one end serves as a first fulcrum and is connected to the frame unit near the swing center axis, while the other end serves as a second fulcrum and is connected to the swing arm. The device includes an avoidance mechanism configured such that when a torque is applied to the swing arm of one party by the telescopic member in the neutral restoration mechanism of one party, the first or second fulcrum of each of the telescopic members is displaced, so as to avoid the telescopic member in the neutral restoration mechanism of the other party from applying torque to the swing arm of the other party.

4. The driving unit according to claim 3, characterized in that, A shaft component is provided at one or the other end of the telescopic component, and the shaft component is hinged to a support portion on the frame unit or a support portion on the swing arm. The avoidance mechanism is composed of an opening formed on the support portion on the frame unit or on the support portion on the swing arm. The opening is configured to engage with the shaft member when the swing arm swings in the extension direction of the telescopic member, and to allow movement of the shaft member when the swing arm swings in the retraction direction of the telescopic member.

5. The driving unit according to claim 1, characterized in that, The linkage mechanism comprises: a first swinging rotating body, linked to the swinging motion of one of the swing arms, rotating about the swinging central axis; a second swinging rotating body, linked to the swinging motion of the other swing arm, rotating about the swinging central axis; a linkage shaft, disposed on a rotation central axis extending parallel to the swinging central axis; a first transmission rotating body and a second transmission rotating body, disposed on the linkage shaft; a first transmission strip, transmitting rotation between the first swinging rotating body and the first transmission rotating body; and a second transmission strip, transmitting rotation between the second swinging rotating body and the second transmission rotating body. The first and second transmission strips are configured such that the rotation directions of the first and second oscillating rotators are opposite to each other.

6. A vehicle comprising: a body section having a main frame; and front wheel units and rear wheel units mounted on the main frame, characterized in that, At least one of the front wheel unit and the rear wheel unit is constituted by a driving unit according to any one of claims 1 to 5.

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