Patent Description:
For a general vehicle, in order to implement steering, a steering gear is required at the vicinity of the wheel to enable the vehicle to turn smoothly. However, the general steering gears are mostly rigid connections. If the tires hit a pothole in the ground while travelling, the tires will instantaneously produce a side angle with respect to the centre-line of the wheel. The side angle not only hinders the travel of the vehicle, but the instantaneous force generated by the tires on hitting the pothole in the ground will also be transmitted to the steering gear.

From the German patent application <CIT>, a steering and wheel drive for an industrial truck is known, which has a drive motor, a transmission, steering motor and steering transmission, through which at least one running wheel installed on a wheel hub is driven and pivoted around a vertical axis, wherein said drive motor, steering motor and steering transmission are installed co-axially with one another and in series one behind the other. This results in an acceptable height, in particular a radially very compact design, as well as an increased degree of integration, for example, by the double use of housing components, so that comparatively low production costs may be achieved. However, the shown structure lacks means to restore deformation.

Another design is known from document <CIT>, wherein a damping element is applied for absorbing a deviation and an eccentricity between a rotary shaft and a worm shaft during rotation of the worm shaft. A first coupling member and a second coupling member are provided, which define a circumferential wall surrounding the outer circumference of the damping element in order to prevent buffering teeth from being in contact with an inner circumferential surface of an accommodating hole even if the buffering teeth protrude radially outward. However, such design is relatively complicated, which causes difficulty and high costs in manufacturing.

Still another design is disclosed in document <CIT>. More specifically, a star-type elastic shaft coupling is applied therein for connecting a worm shaft of a worm gear mechanism and a motor shaft of an electric motor, which are located concentrically with each other. Both the contact surface for the convex portion and the contact surface for a plurality of second convex portions have a constant contact area regardless of the transmission torque. The elastic star-type member is further accommodated within a receiving space formed by a first coupling member and a second coupling member, which makes the elastic member being sandwiched in a radial direction. Displacement and deformation are therefore restricted. However, there lack means of easing damages to wheels, the gear box, the steering gear, and other components.

Since most vehicles do not have protecting devices installed on the steering gear to withstand these instantaneous forces these instantaneous forces can cause damage to the steering gear and the steering gear can easily wear out over time.

The following details how these instantaneous forces can cause damage to the steering gear. In conventional vehicles, the wheels are connected to a gearbox and the gearbox is then connected to the steering gear. A plurality of gears is attached to the gearbox and the gears are engaged with each other. Or dual gears are arranged in the direction of the rotation of the gear-shaft. If the plurality of shafts is coaxial, then once the gearbox receives these instantaneous forces from the wheels the plurality of stacked gears will no longer rotate "coaxially". In order to enable the plurality of stacked gears to rotate coaxially under the influence of these instantaneous forces, a coaxial device is used among the plurality of stacked gears in the gearbox so that a plurality of stacked gears can be rotated coaxially under the impact of these instantaneous external forces.

Typically, such a coaxial device is fixed between two transmission shafts of two machines (e.g., two gears) that need to be coaxial. In these two machines, the shaft of the first machine is connected to the other shaft of the other machine through a coaxial device to calibrate these two shafts. This type of coaxial device has the following designs: one design is to use a coaxial device consisting of flexible part, an external joint, a pin, a nut, an inner joint, a ring, a ring nut and an anti-friction bushing. The flexible part used as a flexible rotating component for the coaxial device, and the flexible part is fixed around each of the parallel shafts of the specific inner and outer coupling portions to form an effective and reliable flexible connection. By absorbing unequal torque and directions from two shafts, these two shafts can be coaxial. However, such a coaxial device has a complicated structure and includes a plurality of shaft joints, pin shafts, and nut fittings, which makes the production difficult; also many accessories may cause the weight of the coaxial device itself to be heavy, which makes the installation more difficult. Consequently, the transmission effect of the shaft becomes inefficient and the design extremely inconvenient to use.

In addition, there is also a design that uses a coaxial device composing a first semi-coaxial, a second semi-coaxial, a positioning sleeve and an elastomer. The symmetrical design of a first semi-coaxial and a second semi-coaxial is applied and the elastomer is mounted between these two semi-coaxial devices during use. These two semi-coaxial devices are connected by screws, and the positioning sleeve is installed to protect and form the entire coaxial device. Although this design is easy to disassemble the two semi-coaxial devices for easy replacement of the elastomer, the coaxial device has too many components, screw holes and screws, and does not constitute an integrated coaxial device. The cost of manufacturing this coaxial device is extremely high, and its production is very inconvenient. In addition, when the elastomer is placed in the sealed space formed by the first semi-coaxial device and the second semi-coaxial device, the elastomer deteriorates easily so that it needs to be replaced very often and is too wasteful.

In addition, vehicles typically travel on relatively flat roads so they receive fewer external impacts and have less impact loads. However, for modern high-precision mechanical equipment, such as wheeled robots or special vehicles, due to the complexity of their travelling environment, their internal steering gears will receive more external impacts than the steering gears of ordinary vehicles causing them more damage.

Given the disadvantages of the previous invention, the present one is a flexible damping device which provides a flexible shock-absorbing parts for connecting two different mechanical shafts and absorbing the torque so that the two machines can be coaxial during the rotating/transmission process. The flexible shock-absorbing part is placed between the two machines and is attached to them. When the flexible shock-absorbing parts is installed in the vehicle, it allowsthe vehicle to absorb any, instantaneous external force received by the wheels while travelling, so that the impact of the external forces on the structure of the motor and the second gear inside the gearbox can be reduced, thereby protecting these parts.

In summary, in order to improve the defects mentioned in the prior technology, the present invention provides a flexible damping device comprising of a plurality of flexible shock-absorbing parts, a plurality of gears and a transmission shaft. The structure of the flexible shock-absorbing parts is very simple and easy to make, replace and maintain; an integrated design can also reduce the weight for the other parts in the flexible damping device. Also, it does not require a lot of screws and nuts so the cost of manufacturing can be greatly reduced and is very convenient to use.

The present invention provides a plurality of flexible shock-absorbing parts according to claim <NUM> for connecting with two shafts in two machines and for absorbing their torques and the two machines is coaxial-running. The flexible shock-absorbing parts are placed between the two machines and also attached to them, and they are arranged radially, on the first plane formed by the X-axis and the Y-axis in the Cartesian coordinate system.

The material for each flexible shock-absorbing part can be metal or polymer, including steel, synthetic rubber and polyurethane. Preferably, the material selected for these parts is spring steel plate.

Preferably, the number of the flexible shock-absorbing parts is more than <NUM>, and the flexible shock-absorbing parts are distributed peripherally over the shaft. When the number of the flexible shock-absorbing parts is an even number, each two pairs should be symmetrically distributed. When the number of flexible shock-absorbing parts is an odd number, the angles between the two flexible shock-absorbing parts should be equally distributed.

In the present invention, the coupling and the flexible shock absorbing parts are applied. When the flexible shock-absorbing parts are impacted and shocked by an external force, these parts will be deformed to absorb the impact caused by the external force so the impact on the structure of the motor and the gears from the external force can be reduced and the protection from these parts is realized. When the external force disappears, the deformation of the flexible shock-absorbing parts is restored so the wheel can return to its initial state to ensure the normal operation of the wheel.

The present invention also provides a flexible damping device according to claim <NUM>, which is composed of a plurality of flexible shock-absorbing parts as described above. It is used for a chassis of a vehicle. The flexible damping device is connected to a motor and the wheel base of the chassis. The features of the flexible damping device are as follows: a coupling, a first gear, an upper shaft, a second gear, a plurality of flexible shock-absorbing parts and a lower shaft. Wherein one end of the coupling is connected to the motor and the other end of the coupling is attached to the second gear; the second gear is engaged with the first gear, the first gear drives the upper shaft to rotate along an upper axis; the flexible shock-absorbing parts are arranged between the upper shaft and the lower shaft; both the lower shaft and the upper shaft rotate along the second axis, with the lower shaft connected to the wheel base, itself attached to a set of wheels. The wheels of the vehicle moves toward a first direction when the vehicle is travelling; when the external force from a second direction is above zero, the flexible shock-absorbing parts will be in a receiving-force state, so they can absorb the external force and ensure that the upper axis and the lower axis are concurrent in the first plane, wherein the first direction is composed of the Y-axis in the Cartesian coordinate system, and the second direction is composed of the X-axis in the Cartesian coordinate system.

Preferably, the flexible shock-absorbing parts are in an initial state when the wheel is subjected to another external force from the second direction.

Preferably, in the initial state, the projected pattern of the flexible shock-absorbing parts on the first plane is the first pattern.

Preferably, in the receiving-force state, the projected pattern of the flexible shock-absorbing parts on the first plane is the second pattern.

Preferably, the first pattern is composed of a plurality of rectangles and the second pattern is composed of a plurality of polygons.

Preferably, wherein the flexible shock-absorbing parts is installed in a gearbox of the travelling vehicle.

The flexible damping device provided by this invention can absorb a large instantaneous external force received by the wheel and reduce the impact of the external force on the structure of the motor and the second gear inside the gear box during the travel of the device in order to protect these parts. When the external force disappears, the deformation of the flexible shock-absorbing parts are restored so that the wheel can return to its initial state to ensure the normal operation of the travelling vehicle.

To make the objects, technical features and advantages of this present invention easy to understand and implement for skilled engineers, a description of the progress of the preferred embodiment will be stated below. The drawings referred to hereinafter are intended to be illustrations of the features of the present invention and are not necessarily required to be fully drawn according to the actual situation. If the description of the embodiments of this present invention relates to technical contents well known to skilled engineers, they will not be described.

Please refer to <FIG> is a cross-sectional view of one embodiment of the disclosed technology in accordance with the present invention. The flexible shock absorbing parts <NUM> of <FIG> are connected to two different shafts of the machines, so as to the two different shafts of the machines is rated coaxially during transmission. The term "coaxial" used here means: the projection line of the rotation axis for two different machines, which are the upper shaft and the lower shaft on the third plane, is a straight line as shown on <FIG>. It is noted to illustrate that the first plane is composed of the X-axis and the Y-axis, the second plane is composed of the Y-axis and Z-axis and the third plane is composed of the X-axis and the Z-axis in the Cartesian coordinate system in entire the specification of this present invention. The two machines rotate by the axes of the upper shaft <NUM> and the lower shaft <NUM>. In the embodiment of the present invention, the axis of the upper shaft <NUM> is called the first axis <NUM>, and the axis of the lower shaft <NUM> is called the second axis <NUM>. The upper shaft <NUM> is connected to the power supply device (not shown in <FIG>). The power supply device drives the upper shaft <NUM> to rotate. Then the upper shaft <NUM> and the lower shaft <NUM> are connected by the flexible shock-absorbing parts <NUM>. As the upper shaft is rotating, a torque is generated, and the torque is transmitted to the gearing wheel <NUM> and the lower shaft <NUM> through the flexible shock-absorbing parts <NUM>. After the lower shaft <NUM> received the torque, it drives the device attached to the lower shaft <NUM> to rotate. The device attached to the lower shaft mentioned above can be any device that can be driven by the steering lower shaft <NUM>, such as a gear or a wheel in a travelling device. If the torque is transmitted without any loss of energy, the lower shaft <NUM> and the upper shaft <NUM> will rotate on the same axis, in the same direction and at the same speed, and then the lower shaft <NUM> drives the device attached to the lower shaft <NUM> to rotate in order to complete the transmission process. It should be noted that "same direction of rotation" means that when the upper shaft <NUM> and the lower shaft <NUM> are rotating, the direction of their torque is the same. The two machines described in all embodiments of the present invention may be gears or mechanical devices with two parallel or coaxial shafts. In the present embodiment, the two machines are the first machine, which includes the upper shaft and a first gear <NUM> and the second machine which includes a gearing wheel <NUM> and the lower shaft <NUM>. The first gear <NUM> is attached to the upper shaft <NUM> and the gearing wheel <NUM> is attached to the lower shaft <NUM>. In other embodiments, these two machines may also include one or more rotating components, which are not limited in the present invention. In addition, the flexible shock-absorbing parts <NUM> may be a plate. The center of the sheet can be cut off so the hollow portion of the flexible shock-absorbing parts <NUM> can be fixed to the shaft. The distribution of the hollow portion (not shown in <FIG>) of the plate and the diameter are not necessarily uniform. They can be uneven diameters in order to match with the upper shaft <NUM> and the lower shaft <NUM>. The changing ranges and sizes of the diameters of the hollow portions are not limited by the claims of the present invention.

In the present invention, the purpose of providing the flexible shock-absorbing parts <NUM> is provided for connecting the upper shaft <NUM> and the lower shaft <NUM> is that if the first axis <NUM> and the second axis <NUM> of two shafts (the upper shaft <NUM> and the lower shaft <NUM>) are not rotated coaxially during the transmission process, the flexible shock-absorbing parts <NUM> can restore the coaxial rotation of the first axis <NUM> and second axis <NUM> from the non-coaxial rotation, to smoothly perform the transmission process. At the same time, the flexible shock-absorbing parts <NUM> can partially absorb the external torque that is transmitted from the lower shaft <NUM> to the upper shaft <NUM> so the first machine can be protected.

Please continue referring to <FIG> is cross-sectional views of the first plane along the W-W Line in <FIG>, showing one embodiment of the installation and connected relationship of the flexible shock-absorbing parts <NUM>. In the present embodiment, the flexible shock-absorbing parts <NUM> are arranged in radial style using the axis of the first axis <NUM> as a reference point so these flexible shock-absorbing parts <NUM> form a sun-like shape surface on the first plane. The material used for these flexible shock-absorbing parts <NUM> is generally selected from the kind that possesses a good pliability, such as metal plate, hard rubber plate, or polyurethane block. Preferably, the material of the flexible shock-absorbing parts <NUM> is spring steel plate. These materials will deform if they receive an external force, but after the external force disappears, these materials will return to their original shape or remain in their deformed shapes. In a specific embodiment, applying <NUM> parts of the flexible shock-absorbing parts <NUM> and using the first axis <NUM> as a point of symmetry configures a point-symmetric arrangement on the first plane. In other embodiment of the present invention, the number of flexible shock-absorbing parts <NUM> may be <NUM>, <NUM> or <NUM> (in even numbers). In another embodiment of the present invention, the number of shock-absorbing parts <NUM> may be an odd number. However, applying the even number of the flexible shock-absorbing parts <NUM> is the best implementation. Viewed from the third direction, the first gear <NUM> is configured above these parts <NUM>. In the present embodiment, the shape of the first gear <NUM> is designed to conform to the shape of the shock-absorbing parts <NUM>. This means the first gear <NUM> shields the position of the flexible shock-absorbing parts <NUM>, and the first gear <NUM> has an opening to expose these parts <NUM>; therefore, when the flexible shock-absorbing parts are viewed from the third direction, they are exposed to the first gear <NUM>.

<FIG> and <FIG> show the detail each part of the flexible shock-absorbing parts and their configuration. They also show their connection with other devices when the flexible shock-absorbing parts <NUM> are at rest. Later, we will detail the flexible shock-absorbing parts <NUM> at the time of use. Please refer to <FIG> is a plan view showing the arrangement of the axes for the two machines while the flexible shock-absorbing parts <NUM> are in an initial state and in accordance with the disclosed technology of the present invention. <FIG> is a simplified view that only shows parts such as the upper shaft <NUM>, the second gear <NUM>, the first axis <NUM>, the lower shaft <NUM>, the second machine and the lower shaft <NUM>. In <FIG>, while in the initial state, which means if the lower shaft <NUM> and the second machine receive an external force of zero, the upper shaft <NUM> and the lower shaft <NUM> are rotated in a coaxial manner and the projection point of the first axis <NUM> of the upper shaft <NUM> and the second axis <NUM> of the lower shaft <NUM> is the same point on the first plane. However, if the lower shaft <NUM> and the second machine receive an external force above zero, the projection point on the first axis <NUM> of the upper shaft <NUM> and the second axis <NUM> of the lower shaft is not the same point on the first plane. Both machines may undergo external impacts or their own vibration so will not rotate co-axially. If both machines do not rotate as such, then the rotating efficiency would be very poor. This means the energy of the first gear <NUM> cannot be completely transmitted to the gearing wheel <NUM> and it results in energy loss and waste. In order to allow both machines to rotate coaxially, the flexible shock-absorbing parts <NUM> need to be installed between the upper shaft <NUM> and the lower shaft <NUM>, as shown in <FIG> and <FIG>, in order to make these both machines rotate on the same axis, so the issue of not rotating coaxially can be avoided. In addition, as the gearing wheel <NUM> receives the external torque from different positions and directions, it may drive the lower shaft to generate the external torque. If this external torque is transmitted to the first machine through the upper shaft <NUM>, which is connected to the lower shaft <NUM>, the first machine may be damaged. The flexible shock-absorbing parts <NUM> can partially absorb the external torque that is transmitted to the upper shaft <NUM> by the lower shaft <NUM> and so provide protection for the first machine.

While in the operating state, the condition of the flexible shock-absorbing parts <NUM> is shown in <FIG> shows a cross-sectional view on the first plane along the W-W Line in <FIG>. <FIG> shows the composition of the flexible shock-absorbing parts under external force, according to the technology disclosed in the present invention. <FIG> is a plan view on the first plane from the section W-W in <FIG>. When the upper shaft <NUM> and the first gear <NUM> receives an external force above zero, this external force is transmitted to the flexible shock-absorbing parts <NUM> and this <NUM> force also causes an additional torque. In the initial state, the flexible shock-absorbing parts <NUM> are rotated according to the rotation of the first gear <NUM> and the gearing wheel <NUM>. Therefore, the rotation axis of the first gear <NUM> and the gearing wheel <NUM>, will share the same rotation speed, force and direction. This means the common centre of mass of the plurality of flexible shock-absorbing parts <NUM> is the same as the first gear <NUM> and the first gearing wheel <NUM>. When the second machine receives an external force during the rotation, the external force and the torque generated by this force are transmitted to the flexible shock-absorbing parts <NUM>. When these flexible shock-absorbing parts <NUM> receive an external force, they instantaneously generate a displacement relative to the upper shaft <NUM>. This means the flexible shock-absorbing parts <NUM> are twisted and deformed. If the additional torque combined with the rotation torque generated originally by the upper shaft <NUM> and the first gear <NUM> exceeds the maximum torque that the flexible shock-absorbing parts <NUM> can withstand, then the flexible shock-absorbing parts <NUM> will be deformed and damaged. Therefore, designing the maximum torque that these flexible shock-absorbing parts <NUM> can withstand is a key point for the present invention. The maximum torque that the flexible shock-absorbing parts <NUM> can withstand is based on the number, size, and the material used for the flexible shock-absorbing parts <NUM>, which is not limited by the present invention. In one embodiment, the flexible shock-absorbing parts <NUM> can withstand a maximum torque of <NUM> to <NUM> N-m. In addition, since the details of each flexible shock-absorbing parts <NUM> are different, the situation of deformation and distortion of each of these flexible shock-absorbing parts <NUM> is different. In the initial state, the projected pattern of the flexible shock-absorbing parts 41on the first plane is the first pattern. However, in the receiving-force (or stressed) state, the projected pattern of the flexible shock-absorbing parts <NUM> on the first plane is the second pattern. The design of the first pattern and the second pattern may be the same or different. The first pattern is composed of a plurality of rectangles, and the second pattern is composed of a plurality of polygons. The polygon may be a plurality of triangles, a plurality of quadrangles, or a combination of a plurality of diamonds.

When the flexible shock-absorbing parts <NUM> is deformed, the first gear <NUM> and the gearing wheel <NUM> rotate coaxially. The flexible shock-absorbing parts <NUM> also rotate coaxially with the first gear <NUM> in the shape of the deformed flexible shock-absorbing parts <NUM>. And this additional torque is absorbed by these parts <NUM> and not transmitted to the upper shaft <NUM>. After the external force disappears, the flexible shock-absorbing parts <NUM> return to the same shape as before the deformation. In another embodiment, after the first gear <NUM> and the second machine rotate coaxially, the centre of mass of the flexible shock-absorbing parts <NUM> returns to its original centre of mass. This means the centre of mass of the first gear <NUM> and the centre of mass of the gearing wheel <NUM> are the same. Therefore, the deformation of the flexible shock-absorbing parts <NUM> disappears, and the first pattern is restored from the second pattern. The flexible shock-absorbing parts <NUM> provided by the above embodiment are not only simple in structure, but also do not require complicated fittings such as pin shafts and nuts. The flexible shock-absorbing parts <NUM> are light in weight and extremely convenient for manufacturing. Moreover, the flexible shock-absorbing parts <NUM> are not easily deteriorated, so that it is not necessary to replace the elastomer very often and it is very convenient to use.

Next, please refer to <FIG>, which is a side view showing the flexible damping device in accordance with the disclosed technology of the present invention. The flexible damping device <NUM> is another embodiment of the present invention. In this embodiment, the flexible damping device <NUM> is fixed in a gear box of the wheel part <NUM> of the travelling vehicle. This travelling vehicle includes mobile wheeled equipment such as special vehicles, wheeled robots, or spacecraft and aircraft, etc. In <FIG>, the gear box is formed by the shell of the gear box <NUM> covering various gear components, the shaft components and the flexible shock-absorbing parts <NUM>. The material of the gearbox box <NUM> is primarily constructed of metal, such as iron or aluminum, to provide substantial protection to the internal components of the gearbox. The first end of the flexible damping device <NUM> is connected to the motor <NUM>, and the second end of the flexible damping device <NUM> is connected to the wheel base <NUM>. The wheels <NUM> are fixed on the wheel base <NUM>. The wheel part <NUM> is connected to the steer base <NUM>. Through this steer base <NUM>, the shell of the gearbox can be installed on the chassis of the travelling vehicle. The motor <NUM> is a machine that controls the wheels <NUM> and the turning direction of the travelling vehicle. Inside of the motor, it has a plurality of gears that output torque for rotating other machines. In the present embodiment, only one set of wheel part <NUM> is illustrated. It is to be understood that the general travelling vehicle is composed of four wheels or and thus includes <NUM> sets of wheel part <NUM>. In some cases, it also has <NUM> sets, <NUM> sets and so on.

Next, please refer to <FIG> is a cross-sectional view showing the internal composition of the flexible damping device according to another embodiment of the disclosed technology of the present invention. The flexible damping device <NUM> includes a coupling <NUM>, a second gear <NUM>, an upper shaft <NUM>, a first gear <NUM>, flexible shock-absorbing parts <NUM> and a lower shaft <NUM>. It also shows one end of the coupling <NUM> is connected to the motor <NUM> and the other end of the coupling <NUM> connected to the second gear <NUM>. The coupling <NUM> enables the motor <NUM> and the second gear <NUM> to rotate on the same axis and ensures that the torque of the motor <NUM> can be transferred to the second gear <NUM> without any loss. The second gear <NUM> is located in the upper shell of gearbox <NUM> to mesh with the first gear <NUM>, and the second gear <NUM> transmits the power supply from the motor <NUM> to the first gear <NUM>. In this embodiment, the first gear <NUM> is a gear set that has a plurality of gears. The implementer can freely adjust the diameter of the gears of the first gear <NUM> to match with the second gear <NUM> in order to reduce the rotational speed and increase the torque, or to increase the rotation speed and reduce the torque. The present invention does not limit the number of gears configured in the first gear <NUM> and the distance between the gears. The first gear <NUM> drives the upper shaft <NUM> to rotate with the first axis <NUM>. The flexible shock-absorbing parts <NUM> is interposed between the upper shaft <NUM> and the lower shaft <NUM>. The lower shaft <NUM> linked to the upper shaft <NUM> rotates with the second axis <NUM>. The lower shaft <NUM> transmits the torque to the wheels <NUM> by the wheel base <NUM> so that the wheels <NUM> can rotate. The wheel base <NUM> and the wheels <NUM> are embodiments of the second machine described above. The wheel base <NUM> is also attached with a plurality of gears to shift the direction of the torque and transmit it to the wheels <NUM> for rotating them <NUM>. When the wheels <NUM> rotate, the direction of the torque is perpendicular to the upper shaft <NUM> and the lower half shaft <NUM>. When an external force is applied to the wheels <NUM> (as indicated by the black arrow in <FIG>), the wheels <NUM> and the wheel base <NUM> are bent and shifted towards the direction of the force, and the lower shaft <NUM> is bent as well; therefore, the second axis <NUM> is shifted from the first axis <NUM> so the two axes are not coaxial. If non-coaxial condition occurs inside the travelling vehicle, the internal gear parts can be worn out, abnormalities of the motor <NUM> may occur and, furthermore, the travelling vehicle itself may veer out of control. The flexible damping device <NUM> is configured in the travelling vehicle. By absorbing the external force, the flexible shock-absorbing parts <NUM> allow the lower half shaft <NUM> and the upper shaft <NUM> inside the gear box to rotate coaxially, so the travelling vehicle can operate smoothly. At the same time, as the wheels <NUM> is subjected to different angles and positions of the torque, a part of the torque is converted into an external force torque for steering the lower shaft <NUM>. The flexible shock-absorbing parts <NUM> can partially absorb the external torque mentioned above so the external torque transmitted to the upper shaft <NUM> is reduced and the second gear <NUM> and the motor <NUM> are protected. In the present embodiment, whether the flexible damping device <NUM> is in the initial state or in the stressed state, the implementation of the present invention, for example, the flexible shock-absorbing parts <NUM>, are the same, so they will not be described again herein.

Please refer to <FIG> is a plane view showing the flexible damping device 6according to another embodiment of the disclosed technology of the present invention. <FIG> is a plan view of the first plane from the section V-V in <FIG>. As shown in <FIG>, the axis of the flexible shock-absorbing parts <NUM> is the first axis <NUM>, and the shaft is configured in the upper shaft. The flexible shock-absorbing parts <NUM> are installed in the upper shell <NUM> of the gearbox. <FIG> only illustrates the configuration of the flexible shock-absorbing parts <NUM> in the gear box. The functions, the connecting relationships of the flexible shock-absorbing parts <NUM> in the initial state and in the stressed state are described in the implementation of the flexible shock-absorbing parts <NUM> of the present invention; therefore, it will not be described here again.

In one embodiment of the present invention, the upper shaft <NUM> is connected to the first gear <NUM> and the lower shaft <NUM> is connected to the gearing wheel <NUM>. The flexible shock-absorbing parts <NUM> are fixed between the first gear <NUM> and the gearing wheel <NUM>. The methods of connecting each part include welding and slot connections. The method of slot connection includes grooving a slot between the first gear <NUM> and the gearing wheel <NUM> and then embedding the flexible shock-absorbing parts <NUM> in the groove, so the first gear <NUM> and the gearing wheel <NUM> can be connected.

Please refer to <FIG>, which is another embodiment of the present invention. <FIG> is an upward or bottom plan view on the first plane from the section W-W in <FIG>. In the present embodiment, the first machine includes the upper shaft <NUM> (not shown) and the first gear <NUM>, which are connected. The second machine includes the lower shaft <NUM>. The plurality of flexible shock-absorbing parts <NUM> are fixed to an annular structure <NUM>, and the plurality of flexible shock-absorbing parts <NUM> mentioned above are arranged radially and evenly distributed in the circumferential direction of the annular structure <NUM>, forming a sun-like shape on the first plane. A space is left between the adjacent flexible shock-absorbing parts <NUM>, and the number of flexible shock-absorbing parts <NUM> is equal to the number of spaces mentioned above. The flexible shock-absorbing parts <NUM> are not fixed to the first gear <NUM> and the second machine. Preferably, the flexible shock-absorbing parts <NUM> are made from resilient materials, including polyurethane or rubber. The flexible shock-absorbing parts <NUM> are fixed to the annular structure <NUM> through press molding or press forming.

One end of the first gear <NUM>, which is connected to the flexible shock-absorbing parts <NUM> is configured with at least one first protrusion <NUM>. The shape of the first protrusion <NUM> is consistent with the space between two adjacent flexible shock-absorbing parts <NUM>. One end of the lower half shaft <NUM> connected to the flexible shock-absorbing parts <NUM> is configured with at least one second protrusion <NUM>. The shape of the second protrusion <NUM> is consistent with the space between the two adjacent flexible shock-absorbing parts <NUM>. The sum of the number of the first protrusions <NUM> and the number of the second protrusions <NUM> shall not exceed the number of the flexible damping pieces <NUM>. Between the position of the first protrusions <NUM> and the position of the second protrusions <NUM> is left a space for the position of the flexible shock-absorbing parts <NUM>. In <FIG>, there are six flexible shock-absorbing parts <NUM>, and the number of spaces between them41 is six, so the number of the second protrusions <NUM> is three and, the number of the first protrusions <NUM> is also three.

The first gear <NUM> is connected to the flexible shock-absorbing parts <NUM> through the first protrusions <NUM>, and the flexible shock-absorbing parts <NUM> are connected to the second protrusions <NUM> of the lower shaft <NUM>. According to the aforementioned, the plurality of flexible shock-absorbing parts <NUM> are fixed closely between the first protrusions <NUM> and the second protrusions <NUM>, so the torque can be transmitted between the upper shaft <NUM> and the lower shaft <NUM>. When an external torque is applied to the lower shaft <NUM>, the flexible shock-absorbing parts <NUM> can absorb the external force through their own deformation, so the first machine can be protected. The flexible shock-absorbing parts <NUM> provided by the present invention can absorb the large instantaneous external force received by the wheels <NUM> during the running of the vehicle, in order reduce the external force on the structure of the motor <NUM> and the second gear <NUM> inside the gearbox and so protect these components. When the external force disappears, the deformation of the flexible shock-absorbing parts <NUM> is restored (or may not be restored) so the wheels <NUM> can return to their initial state to ensure the normal operation of the wheels <NUM> and driving safety.

Claim 1:
A flexible shock-absorbing parts (<NUM>), which connect with an upper shaft (<NUM>) defining a first axis (<NUM>) and a lower shaft (<NUM>) defining a second axis (<NUM>), wherein the upper shaft (<NUM>) connects and drives a first gear (<NUM>) of a first machine and the lower shaft (<NUM>) connects and drives a gearing wheel (<NUM>) of a second machine which includes a wheel base (<NUM>) and a wheel (<NUM>), the flexible shock-absorbing parts (<NUM>) being characterized by
their arrangement between the first gear (<NUM>) and the second machine and tight attachment to them;
the flexible shock-absorbing parts (<NUM>) being arranged in radial style using the first axis (<NUM>) as a reference point;
the first gear (<NUM>) being configured to mesh with a second gear (<NUM>) connected to one end of a coupling (<NUM>) provided with the other end connected to a motor (<NUM>); the coupling (<NUM>) being configured to enable the motor (<NUM>) and the second gear (<NUM>) to rotate coaxially to allow the second gear (<NUM>) to transmit a power supplied from the motor (<NUM>) to the first gear (<NUM>) thereby driving the upper shaft (<NUM>) to rotate around the first axis (<NUM>) and link a rotation of the lower shaft (<NUM>) around the second axis (<NUM>), wherein a torque transmitted to the upper shaft (<NUM>) is reduced by the flexible shock-absorbing parts (<NUM>) during rotation so that the second gear (<NUM>) and the motor (<NUM>) are protected; wherein, while in an initial state, the upper shaft (<NUM>) and the lower shaft (<NUM>) are rotated in a coaxial manner and projection points of the first axis (<NUM>) of the upper shaft (<NUM>) and the second axis (<NUM>) of the lower shaft (<NUM>) are the same point on a first plane, the first plane being composed of the X-axis and the Y-axis in the Cartesian coordinate system.