Differential wheel and trolley

Abstract

The invention provides a differential wheel and a trolley, the differential wheel comprises a wheel, a gear cavity is formed in the side face of the wheel, and a main gear and one or more auxiliary gears meshed with the main gear are placed in the gear cavity; the gear cavity is provided with a limiting part, the auxiliary gear is limited by the limiting part, and the main gear drives the wheels to rotate at the same speed through the auxiliary gear. When the rotating speed of the main gear is different from the rotating speed of the wheel, the auxiliary gear generates displacement in the gear cavity, the auxiliary gear is separated from the limiting part, and the main gear drives the auxiliary gear to idle. During normal walking, the main gear drives the wheels to rotate through the auxiliary gear, and once the rotating speed of the main gear is different from that of the wheels due to turning, the auxiliary gear is separated from the limiting part so that the auxiliary gear can idle, and differential operation is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of a trolley traveling mechanism, and in particular to a trolley differential wheel and a trolley for realizing speed differential of wheels on both sides of the trolley when turning. Background Art

[0002] When the car is turning, the wheels on both sides have different speeds. In order to make the rotation speeds of the wheels on both sides different, a differential appears. For example, the "locking differential assembly and locking differential system" disclosed in CN2014800016807 includes a differential case defining a rotation axis and a gear chamber. The first side gear is located at the first end of the differential case. The second side gear is located at the second end opposite to the first end of the differential case to selectively rotate relative to the differential case. At least two pinions are rotatably supported in the gear chamber and mesh with the first side gear and the second side gear. A solenoid is at the first end. A plunger can be selectively magnetically actuated by the solenoid. A locking ring can be selectively engaged with the second side gear to selectively prevent the side gear from rotating relative to the differential case. At least two relay rods are connected to the plunger and the locking ring so that the locking ring and the plunger maintain a fixed predetermined distance. The locking ring of this structure can selectively engage with the second side gear, so that it can switch between engagement and disengagement to achieve the differential of the inner and outer wheels. However, the structure is more complicated. In small vehicles such as AGVs and four-wheel drive vehicles, the differential structures provided by existing technologies are too complex and too large to be applied to smaller wheels, and the complex structures cannot be miniaturized. Small vehicles lack suitable differential structures. Summary of the invention

[0003] The present invention provides a differential wheel with a simple structure. During normal running, the main gear drives the wheels to rotate through the auxiliary gear. Once the main gear speed is different from the wheel speed during turning, the auxiliary gear idles to achieve differential operation.

[0004] The differential wheel provided by the present invention comprises a wheel, a gear cavity is provided on the side of the wheel, a main gear and one or more sub-gears meshing with the main gear are placed in the gear cavity; the gear cavity has a limiting portion, the sub-gear is limited by the limiting portion, and the main gear drives the wheel to rotate at the same speed through the sub-gear; when the rotation speed of the main gear is different from the rotation speed of the wheel, the sub-gear is displaced in the gear cavity, the sub-gear is separated from the limiting portion, and the main gear drives the sub-gear to rotate idly. When driving straight, the sub-gear is locked, the sub-gear and the wheel form a whole, the main gear drives the wheel through the sub-gear, and the differential wheels on both sides of the car rotate at the same speed. When turning, the wheel speed of the outer differential wheel is different from that of the spur gear, the sub-gear is separated from the limiting portion, the main gear drives the sub-gear to rotate idly, and the sub-gear no longer acts on the wheel.

[0005] Preferably, on the side opposite to the limiting portion, the side wall of the gear cavity at the position of the auxiliary gear is an arc surface, which does not affect the movement of the auxiliary gear between idling and being stuck by the limiting portion.

[0006] Preferably, the limiting portion is a limiting cam, and when the circle where the arc surface is located is concentric with the pinion gear, the limiting cam is located at the tangent point of the circle where the arc surface is located.

[0007] Preferably, when the circle where the arc surface is located is concentric with the pinion gear, the difference between the radius of the circle where the arc surface is located and the radius of the pinion gear is in the range of 0.5-1 mm. This range neither affects the movement of the pinion gear between idling and getting stuck, nor causes the pinion gear to shake arbitrarily in the gear cavity.

[0008] Preferably, the limiting portion is arranged on the path of the auxiliary gear moving from the idling position to the position rotating synchronously with the wheel. The auxiliary gear moves to the limiting portion and is stuck, and then moves in the opposite direction and separates from the limiting portion, and then can idle.

[0009] Preferably, it further comprises a first cover plate, which is installed on one side of the wheel and is used to enclose the main gear and the auxiliary gear in the gear cavity.

[0010] Preferably, a second cover plate is installed on the other side of the wheel, the second cover plate is connected to the main gear, and the second cover plate can rotate relative to the wheel.

[0011] Preferably, the wheel is a split structure, comprising a first wheel component, a second wheel component and an annular rubber ring; after the first wheel component and the second wheel component are connected, an annular groove is formed on the circumference, and the annular rubber ring is arranged in the annular groove.

[0012] The present invention also provides a small car, including a car body, on which the differential wheel of the present invention is installed, the two differential wheels are connected by a transmission shaft, and the two ends of the transmission shaft are respectively connected to the main gears of the two differential wheels.

[0013] Preferably, the trolley is driven by a motor, and the transmission shaft is the output shaft of the motor, or the transmission shaft is driven by the motor.

[0014] The differential wheel of the present invention has a simple structure. When driving straight, the wheels on both sides are driven forward by the conveying shaft. When turning, the outer wheel inertia overspeeds, and the speed of the outer wheel is greater than the secondary gear. At this time, the outer main gear drives the secondary gear to idle, and the outer wheel is actually separated from the transmission pair composed of the transmission shaft, the main gear, and the secondary gear, so as to realize the differential speed of the inner and outer wheels. The present invention is applied to small vehicles such as AGV vehicles and four-wheel drive vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the differential wheel;

[0016] Figure 2 It's the explosion of the differential wheel Figure 1 ;

[0017] Figure 3 It's the explosion of the differential wheel Figure 2 ;

[0018] Figure 4 It is a cross-sectional view of the differential wheel;

[0019] Figure 5 This is a schematic diagram of the differential wheel mounted on the motor;

[0020] Figure 6 This is an exploded view of a split wheel;

[0021] Figure 7 This is a state diagram after the first wheel sub-assembly and the second wheel sub-assembly are assembled.

[0022] In the figure: 1-wheel; 1.1-first wheel sub-component; 1.2-second wheel sub-component; 1.3-annular rubber ring; 1.4-limiting convex angle; 1.5-arc surface; 1.6-gear cavity; 2-main gear; 3-secondary gear; 4-first cover plate; 5-second cover plate; 6-motor. DETAILED DESCRIPTION

[0023] like Figure 1-4 As shown, the differential wheel includes a wheel 1, a gear cavity 1.6 is provided on the first side of the wheel, a main gear 2 and at least one sub-gear 3 meshing with the main gear 2 are placed in the gear cavity, and in this embodiment, there are two sub-gears 3. The main gear 2 is connected to the transmission shaft, and because the transmission shaft is not directly connected to the wheel 1, the wheel 1 can rotate relative to the transmission shaft. There is a gap between the main gear 2 and the two sub-gears 3 and the side wall of the gear cavity, so that the driving wheel and the sub-gears can rotate more smoothly. The differential wheel also includes a first cover plate 4, which is connected to the main gear 2 and seals the main gear and the two sub-gears in the gear cavity. The first cover plate 4 is set to be circular, and the first side of the wheel 1 is provided with a circular groove matching the first cover plate. When the driving wheel rotates, it rotates with the first cover plate 4. When the differential rotates, the first cover plate 4 can rotate relative to the wheel 1.

[0024] In order to realize the differential and the driving of the wheel by the main gear, a limiting part is set on the gear cavity 1.6. When the wheel rotates normally, the driving wheel 2 drives the secondary gear 3 to rotate. Before the secondary gear is limited by the limiting part, the driving of the main gear causes the secondary gear to be displaced in the gear cavity, close to the limiting part, and limited by the limiting part, so that the secondary gear 3 and the wheel 1 are equivalent to forming a connection relationship. At this time, the main gear drives the secondary gear 3 to rotate. Since the secondary gear and the wheel 1 are connected, it naturally drives the wheel 1 to rotate together. At this time, the rotation speed of the wheel 1 is the same as that of the main gear 2. When the rotation speed of the wheel 1 is different from that of the main gear 2, for example, when turning a curve, the wheel speeds on both sides of the car are different, the outer side has a larger rotation speed, and the wheel speed is greater than the main gear speed. The secondary gear 3 is displaced in the direction away from the limiting part, and the secondary gear is separated from the limiting part. The main gear can only drive the secondary gear to idle, and the rotation of the secondary gear cannot act on the wheel, thereby realizing that the rotation speeds of the vehicles on both sides of the car are different, and the wheels and the main gear rotate independently without interfering with each other.

[0025] like Figure 4 As shown, the limiting portion on the gear cavity is a limiting cam 1.4, which is located on the side wall of the gear cavity. On the opposite side of the limiting portion, the gear cavity located at the position of the auxiliary gear is set to a circular arc surface 1.5. When the auxiliary gear is separated from the limiting cam, and when the circle where the circular arc surface 1.5 is located has the same center as the auxiliary gear, the difference between the radius of the circle where the circular arc surface is located and the radius of the auxiliary gear is in the range of 0.5-1 mm, and the limiting cam is located at one of the tangent points of the circle where the circular arc surface 1.5 is located. Figure 4 For example, when the main gear 2 rotates clockwise, the limiting cam for limiting the position of the left auxiliary gear is located at the upper left side, and the limiting cam for limiting the position of the right auxiliary gear is located at the lower right side. If the main gear rotates counterclockwise, the position of the limiting cam 1.4 and the arc surface 1.5 must be swapped. Regardless of how the main gear rotates, the limiting cam is located on the path where the auxiliary gear moves from the position when idling to the position when rotating synchronously with the wheel. If it moves in the direction of the limiting cam, it will be limited by the limiting cam, and the main gear and the wheel will rotate at the same speed; if the auxiliary gear moves in the direction away from the limiting cam, it will separate from the limiting cam, and the main gear and the wheel can rotate differentially.

[0026] When the car is moving straight, the transmission shaft of the car drives the main gear 2 to rotate clockwise (with Figure 4 For example), after the main gear 2 rotates, the main gear 2 drives the sub-gear 3 to rotate, so that the sub-gear 3 is close to the side wall with the limiting cam 1.4, so that the teeth of the sub-gear 3 are stuck by the limiting cam, preventing the sub-gear from idling alone. At this time, the sub-gear and the wheel are equivalent to forming a connection relationship, and the driving force of the main gear acts on the wheel through the sub-gear, and the sub-gear rotates together with the wheel. The wheels on both sides are driven by the transmission shaft, and the wheels on both sides rotate at the same speed.

[0027] When the car turns a corner, the wheel speed on the outside of the curve is greater than the wheel speed on the inside. At this time, the inner wheel is driven by the car's drive shaft to rotate, that is, the secondary gear of the inner differential wheel is stuck with the limit cam of the gear cavity, and is still driven by the main gear. The outer wheel achieves overspeed due to inertia, and the wheel speed is greater than the main gear speed, that is, at this time the wheel rotates counterclockwise relative to the drive shaft and the main gear. At this time, the secondary gear separates from the limit cam and leans against the arc surface on the opposite side, and the secondary gear achieves idling. It should be pointed out that since the car is moving forward, the wheels and the drive shaft are both rotating forward. Since the wheel speed is greater than the drive shaft (main gear), the wheel rotates counterclockwise relative to the main gear. At this time, the secondary gear is separated from the limit cam and leans against the arc surface on the other side.

[0028] When the trolley moves from the curved section to the straight section, the speed of the outer wheel gradually decreases during the movement until it drops below the speed of the main gear. The main gear drives the sub-gear to move toward the limit cam direction until the sub-gear is stuck by the limit cam. The main gear drives the wheel to rotate as a whole through the sub-gear, and the main gear rotates at the same speed as the wheel.

[0029] like Figure 1 , 2 As shown, a second cover plate 5 is provided on the second side opposite to the first side of the wheel, the second cover plate is connected to the main gear 2, and the second cover plate rotates synchronously with the main gear. The second cover plate 5 is set to be circular, and the second side of the wheel is provided with a circular groove matching the second cover plate 5. The bottom of the gear cavity 1.6 is located at the center of the wheel, and a circular through hole is provided. A cylinder matching the circular through hole is provided on one side of the second cover plate 5, and the cylinder is connected to the main gear 2. The transmission shaft can be directly connected to the main gear, or it can be indirectly connected through the first cover plate or the second cover plate, and the main gear is driven to rotate by the transmission shaft. A through hole matching the transmission shaft is provided in the center of the main gear, the first cover plate, and the second cover plate.

[0030] like Figure 6 , 7 As shown, the circumferential surface of the wheel 1 is provided with a pattern and a rubber strip. The wheel can be formed in one piece or in a separate assembly, including a first wheel component 1.1, a second wheel component 1.2 and an annular rubber ring 1.3. After the first wheel component 1.1 is connected to the second wheel component 1.2, an annular groove is formed on the circumference, and the annular rubber ring 1.3 is arranged in the annular groove.

[0031] like Figure 5 As shown, the car includes a car body (not shown in the figure) and differential wheels mounted on the car body, the two differential wheels are on both sides of the car body, and the main gears of the two differential wheels are connected by a transmission shaft. The figure shows a motor 6, the main gear is driven by the motor, and the transmission shaft is the output shaft of the motor 6. Of course, a transmission shaft can also be set separately, the motor drives the transmission shaft, and the transmission shaft drives the main gear.

Claims

1. A differential wheel, comprising a wheel, characterized in that: A gear cavity is provided on the side of the wheel, and a main gear and one or more auxiliary gears meshing with the main gear are placed in the gear cavity; the gear cavity has a limiting portion, and the auxiliary gear is limited by the limiting portion, and the main gear drives the wheel to rotate at the same speed through the auxiliary gear; When the rotation speed of the main gear is different from the rotation speed of the wheel, the auxiliary gear is displaced in the gear cavity, the auxiliary gear is separated from the limiting portion, and the main gear drives the auxiliary gear to idle.

2. The differential wheel according to claim 1, characterized in that: On a side opposite to the limiting portion, a side wall of the gear cavity located at the position of the auxiliary gear is an arc surface.

3. The differential wheel according to claim 2, characterized in that: The limiting portion is a limiting convex angle. When the circle where the arc surface is located is concentric with the pinion gear, the limiting convex angle is located at the tangent point of the circle where the arc surface is located.

4. The differential wheel according to claim 3, characterized in that: When the circle where the arc surface is located is cocentric with the sub-gear, the difference between the radius of the circle where the arc surface is located and the radius of the sub-gear is in the range of 0.5-1 mm.

5. The differential wheel according to claim 1, 2, 3 or 4, characterized in that: The limiting portion is arranged on a path where the auxiliary gear moves from a position when idling to a position when rotating synchronously with the wheel.

6. The differential wheel according to claim 1, 2, 3 or 4, characterized in that: It also includes a first cover plate, which is installed on one side of the wheel and is used to seal the main gear and the auxiliary gear in the gear cavity.

7. The differential wheel according to claim 6, characterized in that: A second cover plate is installed on the other side of the wheel. The second cover plate is connected to the main gear and can rotate relative to the wheel.

8. The differential wheel according to claim 1, 2, 3 or 4, characterized in that: The wheel is a split structure, comprising a first wheel component, a second wheel component and an annular rubber ring; after the first wheel component and the second wheel component are connected, an annular groove is formed on the circumference, and the annular rubber ring is arranged in the annular groove.

9. The differential wheel according to claim 1, 2, 3 or 4, characterized in that: The number of the secondary gears is 2.

10. A small vehicle, comprising a vehicle body, characterized in that: The vehicle body is provided with two differential wheels as claimed in any one of claims 1 to 9, the two differential wheels are connected via a transmission shaft, and the two ends of the transmission shaft are respectively connected to the main gears of the two differential wheels.

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