Motorized vehicle having forward and backward differential structure

Abstract

A motorized vehicle includes a plurality of single-direction thrust bearings mounted between each of the two rear wheels and the propeller shaft. The single-direction thrust bearings located at one rear wheel is used to drive the motorized vehicle to move forward, and the single-direction thrust bearings located at the other rear wheel is used to drive the motorized vehicle to move backward. Thus, when the two rear wheels are subjected to a drag and cannot be rotated with the propeller shaft synchronously, the single-direction thrust bearings will idle, thereby producing a differential effect.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a motorized vehicle, and more particularly to a motorized vehicle having a forward and backward differential structure.

[0003] 2. Description of the Related Art

[0004] A conventional motorized vehicle comprises a differential mounted on the transmission gear of the gear box. The differential consists of a bevel gear set. The power of the motor is reduced by the reduction mechanism. Then, the reduced power is transmitted by the transmission gear of the gear box and the bevel gear of the differential to the propeller shafts at the left and right sides, to drive and rotate the wheels at the left and right sides. When the motorized vehicle is turned, the turning diameter of the wheel at the inner side is shorter than that of the wheel at the outer side, so that the differential consisting of the bevel gear set is used to balance the difference of the rotation speed between the wheel at the inner side and the wheel at the outer side.

[0005] However, the conventional differential consisting of a bevel gear set has a complicated construction, thereby increasing costs of fabrication, and thereby causing inconvenience in assembly and maintenance.

SUMMARY OF THE INVENTION

[0006] The primary objective of the present invention is to provide a motorized vehicle having a forward and backward differential structure.

[0007] Another objective of the present invention is to provide a motorized vehicle, wherein when the two rear wheels are subjected to a drag or resistance and cannot be rotated with the propeller shaft synchronously, the single-direction thrust bearing will idle, thereby producing a differential effect.

[0008] A further objective of the present invention is to provide a motorized vehicle, wherein the single-direction thrust bearings located at one of the two rear wheels is used to drive the motorized vehicle to move forward, and the single-direction thrust bearings located between the other rear wheel is used to drive the motorized vehicle to move backward.

[0009] A further objective of the present invention is to provide a motorized vehicle having a differential structure which can replace the conventional differential consisting of a bevel gear set, thereby reducing costs of fabrication, and thereby simplifying the construction.

[0010] In accordance with the present invention, there is provided a motorized vehicle, comprising:

[0011] two rear wheels;

[0012] a propeller shaft mounted on the two rear wheels and having two ends; and

[0013] a plurality of single-direction thrust bearings mounted between each of the two rear wheels and the propeller shaft, wherein:

[0014] the single-direction thrust bearings located between one of the two rear wheels and a first end of the propeller shaft has a rotation direction opposite to a normal rotation direction of the propeller shaft to drive the motorized vehicle to move forward; and

[0015] the single-direction thrust bearings located between the other one of the two rear wheels and a second end of the propeller shaft has a rotation direction opposite to a reverse rotation direction of the propeller shaft to drive the motorized vehicle to move backward.

[0016] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a partially exploded perspective view of a motorized vehicle in accordance with the preferred embodiment of the present invention;

[0018] FIG. 2 is a front plan cross-sectional assembly view of the motorized vehicle as shown in FIG. 1;

[0019] FIG. 3 is a top plan cross-sectional assembly view of the motorized vehicle as shown in FIG. 1;

[0020] FIG. 4 is a perspective assembly view of the differential structure of the motorized vehicle in accordance with the preferred embodiment of the present invention;

[0021] FIG. 5 is an exploded perspective view of the differential structure of the motorized vehicle in accordance with the preferred embodiment of the present invention;

[0022] FIG. 6 is a side plan cross-sectional view of the differential structure of the motorized vehicle as shown in FIG. 4;

[0023] FIG. 7 is a schematic top plan operational view showing the turning state of the motorized vehicle in accordance with the preferred embodiment of the present invention;

[0024] FIG. 8 is a side plan cross-sectional assembly view showing the normal transmission state of the motorized vehicle in accordance with the preferred embodiment of the present invention; and

[0025] FIG. 9 is a side plan cross-sectional assembly view showing the differential state of the motorized vehicle in accordance with the preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Referring to the drawings and initially to FIGS. 1-6, a motorized vehicle 10 having a forward and backward differential structure in accordance with the preferred embodiment of the present invention has a rear portion provided with a propeller shaft 11 having two ends each provided with a catch flange 12, a keyway 13 (see FIG. 6), and an outer thread 14 (see FIG. 6).

[0027] Each of the two ends of the propeller shaft 11 is provided with a bearing cap 20, two single-direction thrust bearings 30, a bearing seat 40, and a fixing member 50.

[0028] The bearing seat 40 is formed with a plurality of screw bores 41. The bearing cap 20 is formed with a plurality of through holes 21. The motorized vehicle 10 further comprises a plurality of locking screws 22 each extended through a respective one of the through holes 21 and each screwed into a respective one of the screw bores 41, thereby fixing the bearing cap 20 on the bearing seat 40.

[0029] Each of the two single-direction thrust bearings 30 is mounted between the bearing seat 40 and the propeller shaft 11. Each of the two single-direction thrust bearings 30 has an inner race formed with an inner keyway 31.

[0030] The motorized vehicle 10 further comprises a first key 32 secured in the inner keyway 31 of each of the two single-direction thrust bearings 30 and the keyway 13 of the propeller shaft 11, so that each of the two single-direction thrust bearings 30 is combined with the propeller shaft 11.

[0031] Each of the two single-direction thrust bearings 30 has an outer race formed with an outer keyway 310. The bearing seat 40 has two sides each formed with a keyway 42. The motorized vehicle 10 further comprises two second keys 320 each secured in the outer keyway 310 of a respective one of the two single-direction thrust bearings 30 and the keyway 42 of the bearing seat 40, so that each of the two single-direction thrust bearings 30 is combined with the bearing seat 40.

[0032] One of the two single-direction thrust bearings 30 is rested on and limited by the catch flange 12 of the propeller shaft 11 and the bearing cap 20.

[0033] The fixing member 50 is secured on the propeller shaft 11 and is rested on the other one of the two single-direction thrust bearings 30. Preferably, the fixing member 50 is formed with an inner thread 51 screwed on the outer thread 14 of the propeller shaft 11, so that the fixing member 50 is fixed on the propeller shaft 11.

[0034] The bearing seat 40 has a periphery provided with a fixing board 43, and the motorized vehicle 10 further comprises two rear wheels 60 each secured on the fixing board 43 of the respective bearing seat 40.

[0035] The fixing board 43 of the bearing seat 40 is formed with a plurality of through holes 44. Each of the two rear wheels 60 is formed with a plurality of through holes 62. The motorized vehicle 10 further comprises a plurality of locking bolts 45 each extended through a respective one of the through holes 44 of the fixing board 43 of the bearing seat 40 and a respective one of the through holes 62 of the respective rear wheel 60, so that each of the two rear wheels 60 is fixed on the fixing board 43 of the respective bearing seat 40.

[0036] In addition, the two single-direction thrust bearings 30 located at a first end of the propeller shaft 11 has a rotation direction opposite to the normal rotation direction (when the motorized vehicle 10 is moved forward) of the propeller shaft 11 to drive the motorized vehicle 10 to move forward, while the two single-direction thrust bearings 30 located at a second end of the propeller shaft 11 has a rotation direction opposite to the reverse rotation direction (when the motorized vehicle 10 is moved backward) of the propeller shaft 11 to drive the motorized vehicle 10 to move backward.

[0037] In operation, referring to FIGS. 7-9 with reference to FIGS. 1-6, when the motorized vehicle 10 is turned around, the rear wheel 60 at the inner side cannot be rotated with the propeller shaft 11 synchronously. At this time, the single-direction thrust bearing 30 idles, thereby producing a differential effect, thereby reducing the turning diameter of the motorized vehicle 10, and thereby reducing wear of the rear wheels 60.

[0038] Accordingly, the single-direction thrust bearings located at one of the two rear wheels is used to drive the motorized vehicle to move forward, and the single-direction thrust bearings located between the other rear wheel is used to drive the motorized vehicle to move backward. Thus, when the two rear wheels are subjected to a drag or resistance and cannot be rotated with the propeller shaft synchronously, the single-direction thrust bearing will idle, thereby producing a differential effect.

[0039] In practice, the motorized vehicle is driven by the two rear wheels. For example, the single-direction thrust bearings located at the left rear wheel is used to drive the motorized vehicle to move forward. At this time, the single-direction thrust bearings located at the right rear wheel idles. On the contrary, the single-direction thrust bearings located at the right rear wheel is used to drive the motorized vehicle to move backward. At this time, the single-direction thrust bearings located at the left rear wheel idles. Thus, the single-direction thrust bearings mounted on the two rear wheels form a differential effect when the motorized vehicle is turned or driven on an abnormal road condition.

[0040] Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.

Claims

1. A motorized vehicle, comprising:

two rear wheels;

a propeller shaft mounted on the two rear wheels and having two ends; and

a plurality of single-direction thrust bearings mounted between each of the two rear wheels and the propeller shaft, wherein:

the single-direction thrust bearings located between one of the two rear wheels and a first end of the propeller shaft has a rotation direction opposite to a normal rotation direction of the propeller shaft to drive the motorized vehicle to move forward; and

the single-direction thrust bearings located between the other one of the two rear wheels and a second end of the propeller shaft has a rotation direction opposite to a reverse rotation direction of the propeller shaft to drive the motorized vehicle to move backward.

2. The motorized vehicle in accordance with claim 1, wherein each of the two ends of the propeller shaft is provided with a bearing cap, two single-direction thrust bearings, a bearing seat, and a fixing member.

3. The motorized vehicle in accordance with claim 2, wherein the bearing seat is formed with a plurality of screw bores, the bearing cap is formed with a plurality of through holes, and the motorized vehicle further comprises a plurality of locking screws each extended through a respective one of the through holes and each screwed into a respective one of the screw bores, thereby fixing the bearing cap on the bearing seat.

4. The motorized vehicle in accordance with claim 2, wherein each of the two single-direction thrust bearings is mounted between the bearing seat and the propeller shaft.

5. The motorized vehicle in accordance with claim 2, wherein each of the two ends of the propeller shaft is formed with a keyway, each of the two single-direction thrust bearings has an inner race formed with an inner keyway, and the motorized vehicle further comprises a first key secured in the inner keyway of each of the two single-direction thrust bearings and the keyway of the propeller shaft, so that each of the two single-direction thrust bearings is combined with the propeller shaft.

6. The motorized vehicle in accordance with claim 2, wherein each of the two single-direction thrust bearings has an outer race formed with an outer keyway, the bearing seat has two sides each formed with a keyway, and the motorized vehicle further comprises two second keys each secured in the outer keyway of a respective one of the two single-direction thrust bearings and the keyway of the bearing seat, so that each of the two single-direction thrust bearings is combined with the bearing seat.

7. The motorized vehicle in accordance with claim 2, wherein each of the two ends of the propeller shaft is formed with a catch flange, one of the two single-direction thrust bearings is rested on and limited by the catch flange of the propeller shaft and the bearing cap.

8. The motorized vehicle in accordance with claim 7, wherein the fixing member is secured on the propeller shaft and is rested on the other one of the two single-direction thrust bearings.

9. The motorized vehicle in accordance with claim 2, wherein each of the two ends of the propeller shaft is formed with an outer thread, and the fixing member is formed with an inner thread screwed on the outer thread of the propeller shaft, so that the fixing member is fixed on the propeller shaft.

10. The motorized vehicle in accordance with claim 2, wherein the bearing seat has a periphery provided with a fixing board, and each of the two rear wheels is secured on the fixing board of the respective bearing seat.

11. The motorized vehicle in accordance with claim 10, wherein the fixing board of the bearing seat is formed with a plurality of through holes, each of the two rear wheels is formed with a plurality of through holes, and the motorized vehicle further comprises a plurality of locking bolts each extended through a respective one of the through holes of the fixing board of the bearing seat and a respective one of the through holes of the respective rear wheel, so that each of the two rear wheels is fixed on the fixing board of the respective bearing seat.