CN209851997U - Electric vehicle wheel - Google Patents

Abstract

The present application relates to a motorized wheel. The electric wheel comprises a built-in suspension guide mechanism and a motor. The built-in suspension guide mechanism is connected with the frame, the built-in suspension guide mechanism is connected with the hub through a bearing, and the hub drives the frame to move through the built-in suspension guide mechanism. The motor is connected with the built-in suspension guide mechanism, and the motor is connected with the frame through the built-in suspension guide mechanism, so that the unsprung mass of the vehicle is reduced. When the electric wheel meets bumpy road conditions, the built-in suspension guide mechanism absorbs vibration energy. The vibration of the motor and the frame is reduced, and the running smoothness of the vehicle is improved.

Description

Electric vehicle wheel

Technical Field

The application relates to the technical field of automobiles, in particular to an electric wheel.

Background

In the electric drive technology, the distributed drive motor arrangement mode is easy to implement optimization of a power system control strategy, and the driving dynamics performance of a vehicle is improved. In the distributed driving scheme, a large number of mechanical transmission parts can be omitted in the in-wheel motor driving arrangement mode, so that the chassis has the advantages of compact structure and high energy utilization efficiency.

However, distributed drive increases the unsprung mass of the vehicle, which has a very important impact on the comfort of the vehicle. When unsprung mass increases and wheels encounter jolts, springs and vibration damping devices take longer to absorb vibration energy, and vehicle body vibration is intensified.

SUMMERY OF THE UTILITY MODEL

Therefore, the electric wheel is needed to be provided aiming at the problems that the motor is arranged in the wheel, the unsprung mass of the automobile is increased, and the running smoothness of the automobile is influenced.

An electric wheel is used for driving a vehicle frame to move. The electric wheel comprises a rim, a spoke, a hub, a built-in suspension guide mechanism and a motor. The rim is coaxial with the hub. The rim passes through the spoke with wheel hub is connected, just wheel hub with the frame sets up relatively. One side of the built-in suspension guide mechanism is connected with the hub through a bearing. And the other side of the built-in suspension guide mechanism is used for being connected with the frame. The built-in suspension guide mechanism is a four-bar linkage mechanism and is used for attenuating vertical vibration transmitted to the frame by the wheel hub. The motor is connected with the built-in suspension guide mechanism and used for attenuating the vertical vibration transmitted to the motor by the wheel hub.

In one embodiment, the brake mechanism is disposed between the hub and the frame.

In one embodiment, the braking mechanism includes a brake disc and a brake caliper. The brake disc set up in wheel hub is close to one side of frame, just the brake disc with wheel hub coaxial coupling. The brake caliper is arranged on the built-in suspension guide mechanism and used for braking in cooperation with the brake disc.

In one embodiment, the four-bar linkage includes an inboard wheel bracket, a motor mount, an upper swing arm, and a lower swing arm. The built-in wheel bracket is connected with the hub through the bearing. The motor fixing frame and the built-in wheel bracket are oppositely arranged at intervals. One end of the upper swing arm is rotatably connected with the built-in wheel bracket. The other end of the upper swing arm is rotatably connected with the motor fixing frame. The lower swing arm and the upper swing arm are oppositely arranged at intervals. One end of the lower swing arm is rotatably connected with the built-in wheel bracket, and the other end of the lower swing arm is rotatably connected with the motor fixing frame.

In one embodiment, the electric wheel further comprises at least one vibration reduction assembly. And two ends of the vibration reduction assembly are respectively and rotatably connected with any two of the built-in wheel bracket, the motor fixing frame, the upper swing arm or the lower swing arm.

Motorized wheel in one embodiment, the vibration attenuation module includes a damping element. And two ends of the damping element are respectively and rotatably connected with any two of the built-in wheel bracket, the motor fixing frame, the upper swing arm or the lower swing arm.

In one embodiment, the vibration damping assembly further comprises a resilient element. The elastic element is sleeved on the periphery of the damping element and used for synchronously moving with the damping element.

In one embodiment, the motor further comprises an output, and the electric wheel further comprises a flexible transmission connected between the output and the hub.

In one embodiment, the flexible transmission mechanism includes a double cross-shaft universal transmission mechanism, a rzeppa universal transmission mechanism, a three-fork universal transmission mechanism, a slider flexible transmission mechanism, a chain transmission mechanism, or the like.

In one embodiment, the motorized wheel further comprises a speed reduction mechanism. The flexible transmission mechanism is connected between the output end and the flexible transmission mechanism.

The application provides an electric wheel, electric wheel includes built-in suspension guiding mechanism and motor. The built-in suspension guide mechanism is connected with the frame, the built-in suspension guide mechanism is connected with the hub through a bearing, and the hub drives the frame to move through the built-in suspension guide mechanism. The motor is connected with the built-in suspension guide mechanism, and the motor is connected with the frame through the built-in suspension guide mechanism, so that the unsprung mass of the vehicle is reduced. When the electric wheel meets bumpy road conditions, the built-in suspension guide mechanism absorbs vibration energy. The vibration of the motor and the frame is reduced, and the running smoothness of the vehicle is improved.

Drawings

Fig. 1 is a schematic structural view of the electric wheel provided in embodiment 1 of the present application;

fig. 2 is a schematic structural view of the electric wheel provided in embodiment 2 of the present application;

fig. 3 is a sectional view a-a of the electric wheel provided in embodiment 2 of the present application;

fig. 4 is a schematic structural view of the electric wheel provided in embodiment 3 of the present application;

fig. 5 is a B-B sectional view of the electric wheel provided in embodiment 3 of the present application;

fig. 6 is a partially enlarged view of C of the electric wheel provided in embodiment 3 of the present application.

Reference numerals:

electric vehicle wheel 100

Rim 101

Spoke 102

Hub 103

Bearing 106

Built-in suspension guide mechanism 20

Vehicle frame 200

Connecting assembly 300

Built-in wheel carrier 210

Motor fixing frame 220

Supporting part 221

Upper swing arm 230

Lower swing arm 240

Motor 30

Output terminal 310

Shock absorbing assembly 40

Damping element 410

Elastic element 420

Brake mechanism 50

Brake disc 510

Brake caliper 520

Flexible transmission mechanism 60

Speed reduction mechanism 70

Speed reduction output 710

Planetary gear set 80

Sun gear 810

Planet gear 820

Cylindrical gear set 90

First cylindrical gear 910

Second cylindrical gear 920

Third cylindrical gear 930

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings). In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be considered as limiting the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Referring to fig. 1, an embodiment of the present application provides an electric wheel 100 for driving a frame 200. The electric vehicle wheel 100 includes a rim 101, spokes 102, a hub 103, an internal suspension guide mechanism 20, and a motor 30. The rim 101 is coaxial with the hub 103. The rim 101 is connected to the hub 103 through the spokes 102, and the rim 101 is disposed opposite to the frame 200. One side of the built-in suspension guide mechanism 20 is connected to the hub 103 via a bearing 106. The other side of the built-in suspension guide mechanism 20 is used for connecting with the vehicle frame 200. The built-in suspension guide mechanism 20 is a four-bar linkage mechanism for damping vertical vibration of the wheel hub 103 transmitted to the vehicle frame 200.

The motor 30 is connected to the built-in suspension guide mechanism 20, and is configured to damp vertical vibration transmitted from the hub 103 to the motor 30.

The application provides an electric vehicle wheel 100. The motor-driven wheel 100 includes the built-in suspension guide mechanism 20 and the motor 30. The built-in suspension guide mechanism 20 is connected to the vehicle frame 200. The built-in suspension guide mechanism 20 is connected to the hub 103 via a bearing 106. The wheel hub 103 drives the frame 200 to move through the built-in suspension guide mechanism 20. The motor 30 is connected to the built-in suspension guide mechanism 20. The motor 30 is connected to the vehicle frame 200 through the built-in suspension guide mechanism 20, and unsprung mass of the vehicle is reduced. When the electric vehicle wheel 100 encounters a bumpy road condition, the built-in suspension guide mechanism 20 absorbs vibration energy. The vibration of the motor 20 and the frame 200 is reduced to increase the smoothness of the vehicle running.

In one embodiment, the built-in suspension guide mechanism 20 is coupled to the vehicle frame 200 by a coupling assembly 300. The vehicle body frame 200 suspends the motor 30 by the built-in suspension guide mechanism 20. In one embodiment, the frame 200 may be a vehicle body axle or beam, or the like. The frame 200 includes an elastic damping element, which provides an elastic force and a damping force to the frame 200, and increases the running stability of the frame 200.

The built-in suspension guide mechanism 20 can also absorb the vibration of the electric vehicle wheel 100 and block the transmission of the vibration. The built-in suspension guide mechanism 20 can also block the vibration of the vehicle frame 200, reduce the vibration amplitude of the motor 30, and enable the motor 30 to be in a relatively stable environment.

The motor 30 may convert electric energy into rotational kinetic energy. The motor 30 is arranged between the wheel hub 103 and the frame 200 and protected by the wheel rim 101, the spoke 102 and the wheel hub 103, so that external collision and damage are avoided.

In one embodiment, the motor 30 is disposed between the hub 103 and the frame 200, so that a large number of mechanical transmission components can be omitted, and the advantages of compact chassis mechanism and high energy utilization efficiency can be achieved. Meanwhile, the motor 30 is arranged in the electric wheel 100, so that the space of a chassis can be further saved, and the gravity center of the whole vehicle is reduced, the axle load distribution is optimized, and the like.

The type of the motor 30 may be selected according to design requirements. The motor 30 may be an inner rotor motor or an outer rotor motor. In one embodiment, the motor 30 is an internal rotor motor. The rotor of the motor 30 is connected to the output end 310 for power output. The rotor of the electron 30 is coaxial with the hub 103. The motor 30 may be a general motor or a hub motor. When the motor 30 is a general motor, a rotation reduction device needs to be added to the electric wheel 100 to increase the torque of the electric wheel 100.

In one embodiment, the motor 30 is additionally provided with a controller, so that the control strategy of the power system is optimized, and the driving dynamics performance of the vehicle is improved. The distributed driving control algorithm embedded in the controller can realize multiple functions, comprehensively improve the operation stability of the vehicle and comprehensively improve the dynamic characteristics of the vehicle under high speed and various road conditions.

In one embodiment, the electric vehicle wheel 100 further includes a braking mechanism 50, and the braking mechanism 50 is disposed between the wheel hub 103 and the vehicle frame 200, and protected by the wheel rim 101, the wheel disc 102 and the wheel hub 103 to avoid external collision and damage.

In one embodiment, the braking mechanism 50 includes a brake rotor 510 and a brake caliper 520. The brake disc 510 is disposed on one side of the wheel hub 103 close to the frame 200, and the brake disc 510 is coaxially connected to the wheel hub 103. The brake caliper 520 is provided to the built-in suspension guide mechanism 20, and is configured to cooperate with the brake disc 510 for braking.

In one embodiment, the four-bar linkage includes a built-in wheel bracket 210, a motor mount 220, an upper swing arm 230, and a lower swing arm 240. The inner wheel bracket 210 is connected to the hub 103 via the bearing 106. The motor fixing frame 220 is disposed opposite to the inner wheel bracket 210 at a distance. One end of the upper swing arm 230 is rotatably connected to the inner wheel bracket 210. The other end of the upper swing arm 230 is rotatably connected to the motor fixing frame 220. The lower swing arm 240 is disposed opposite to the upper swing arm 230 at a distance. One end of the lower swing arm 240 is rotatably connected to the wheel bracket 210, and the other end of the lower swing arm 240 is rotatably connected to the motor holder 220.

The built-in suspension guide mechanism 20 is a four-bar linkage. The connecting rods of the four-bar linkage mechanism are hinged and can rotate relatively. The four-bar linkage mechanism can be a crank rocker mechanism, a double-crank mechanism and a double-rocker mechanism in a rotating mode. In one embodiment, the built-in suspension guide mechanism 20 is a double rocker mechanism that reduces the amplitude of vibration between the vehicle frame 200 and the motor 20.

In one embodiment, the built-in wheel bracket 210, the motor fixing bracket 220, the upper swing arm 230 and the lower swing arm 240 are hinged end to form the four-bar linkage. The shapes of the inner wheel bracket 210, the motor fixing bracket 220, the upper swing arm 230 and the lower swing arm 240 may be determined according to practical applications. In one embodiment, the inner wheel bracket 210 is in a straight shape, and the bearing 106 is disposed at a middle portion of the inner wheel bracket 210 in a length direction. The upper swing arm 230 and the lower swing arm 240 are hinged to both ends of the built-in wheel bracket 210, respectively.

Referring to fig. 2 and 3, the inner wheel bracket 210 may be cross-shaped. The first and second bars of the cross are perpendicularly crossed. The upper swing arm 230 and the lower swing arm 240 are rotatably connected to the second lever. The brake caliper 520 is disposed on the first rod for cooperating with the brake disc 510 for braking.

The motor 30 and the brake mechanism 50 are both located in the built-in suspension guide mechanism 20, and can be integrally taken out of the opening 104 for maintenance.

In one embodiment, the brake mechanism is a drum brake. The drum brake includes a brake drum and a brake shoe. The brake shoe is arranged on one side, close to the frame, of the wheel hub, and the brake drum is arranged on the built-in wheel bracket and used for being matched with the brake disc to brake.

The bearing 106 includes an outer sleeve and an inner sleeve. The outer sleeve is fixedly connected to the middle of the inner wheel bracket 210. The inner shaft is sleeved on the hub 103. The hub 103 supports and drives the four-bar linkage to move. The movement of the hub 103 is in the form of rolling about an axis and parallel movement along the ground. The hub 103 drives the four-bar linkage mechanism to move in parallel along the ground.

The built-in wheel bracket 210, the motor fixing bracket 220, the upper swing arm 230 or the lower swing arm 240 may be in the form of a wishbone type independent suspension, a trailing arm type independent suspension, a single-arm type independent suspension in which an electric wheel moves in a kingpin direction, or the like. The cross-arm type independent suspension comprises a single cross arm, a double cross arm or a Macpherson type. The trailing arm type independent suspension comprises a single trailing arm or double trailing arms and the like. The electric vehicle wheel is movable in the kingpin direction and comprises a candle type and the like.

In one embodiment, the motorized wheel 100 further comprises at least one vibration reduction assembly 40. Two ends of the vibration damping assembly 40 are respectively rotatably connected to any two of the built-in wheel bracket 210, the motor fixing bracket 220, the upper swing arm 230, or the lower swing arm 240.

The damping assembly 40 has a damping effect. In one embodiment, the vibration reduction assembly may be disposed outside the four-bar linkage mechanism or disposed inside the four-bar linkage mechanism. When the electric vehicle wheel 100 runs on a bumpy road, the hub 103 moves up and down perpendicular to the ground. The wheel hub 103 drives the built-in wheel bracket 210 to move up and down. The inner wheel carrier 210 rotates relative to the upper swing arm 230 and the lower swing arm 240. The upper swing arm 230 and the lower swing arm 240 drive the motor fixing frame 220 to move. The four-bar linkage is hinged, and vibration energy is consumed by rotation.

The vibration damping unit 40 is disposed between any two of the built-in wheel bracket 210, the motor fixing bracket 220, the upper swing arm 230, or the lower swing arm 240, and can absorb kinetic energy and reduce vibration of the frame 200 and the motor 30.

In one embodiment, there are two of the damping assemblies 40. One end of one of the vibration reduction assemblies 40 is rotatably connected to the motor fixing frame 220, and the other end thereof is rotatably connected to the upper swing arm 230. One end of the other vibration damping assembly 40 is rotatably connected with the motor fixing frame 220, and the other end is rotatably connected with the lower swing arm 240. The two vibration reduction assemblies 40 are arranged oppositely, so that the vibration reduction is balanced, and the running stability of the vehicle is improved.

In one embodiment, one end of the damping assembly 40 is rotatably connected to the inner wheel bracket 210, and the other end of the damping assembly 40 is rotatably connected to the upper swing arm 230.

In one embodiment, the vibration attenuation module 40 includes a damping element 410. Both ends of the damping element 410 are respectively rotatably connected to any two of the built-in wheel bracket 210, the motor fixing bracket 220, the upper swing arm 230, or the lower swing arm 240.

The damping element 410 reduces the ability of the structure to transmit vibrations. In the design of the vibration isolation structure of the mechanical system, the damping element 410 can significantly improve the effects of vibration isolation and vibration reduction.

In one embodiment, the damping assembly 40 further includes a resilient member 420. The damping element 410 and the elastic element 420 may be provided independently or may be associated with each other.

In one embodiment, the elastic element 420 is sleeved around the damping element 410 for synchronous movement with the damping element 410. The elastic element 420 is sleeved around the damping element 410, and can play a role of buffering. The elastic element 420 drives the damping element 410 to expand and contract together. The damping member 410 gradually absorbs the kinetic energy during the expansion and contraction process, and the elastic member 420 is gradually reduced in the expansion and contraction distance. The two are mutually matched to avoid being stuck.

The electric wheel 200 can significantly reduce the vibration of the frame 200 and the motor 30 in a motor driving mode, improve the smoothness of the vehicle, and greatly improve the working environment of the motor. The coherence of the vertical vibration characteristics of the electric wheel 100 and the vertical vibration characteristics of the motor 30 is reduced, and the dynamic load of the electric wheel is greatly reduced, so that the service life of the tire is prolonged, the running safety of the vehicle is improved, and the possibility of the vehicle jumping off the ground is reduced.

In one embodiment, the motor 30 further comprises an output end 310, and the electric vehicle wheel 100 further comprises a flexible transmission 60 connected between the output end 310 and the wheel hub 103.

The flexible transmission mechanism 60 may be a double-cross universal flexible transmission mechanism, a rzeppa universal flexible transmission mechanism, a three-fork universal flexible transmission mechanism, a slider flexible transmission mechanism, or a chain flexible transmission mechanism. In one embodiment, the flexible drive mechanism 60 is a dual cross-axis universal flexible drive mechanism. The double-cross-shaft universal flexible transmission mechanism has the advantages of large bearing capacity, large transmitted torque, stable carrying, low noise and convenient assembly, disassembly and maintenance.

Referring to fig. 4 and 5 together, in one embodiment, the electric wheel further includes a speed reduction mechanism 70. The speed reduction mechanism 70 includes at least one stage of planetary gear speed reduction mechanism, a spur gear speed reduction mechanism, a helical gear speed reduction mechanism, and other common speed reduction mechanisms.

In one embodiment, the reduction mechanism 70 includes a planetary gear set 80 and a cylindrical gear set 90. The planetary gear set 80 includes a sun gear 810 and planet gears 820. The sun gear 810 is fixedly connected to the output end 310. The planet gears 820 rotate about the sun gear 810.

Referring to fig. 6, in one embodiment, the motor holder 220 includes a support portion 221. The support portion 221 is used to support the motor 30 and the planetary gear set 80, so as to increase structural stability.

The cylindrical gear set 90 includes a first cylindrical gear 910, a second cylindrical gear 920, and a third cylindrical gear 930. The first cylindrical gear 910 and the second cylindrical gear 920 are concentrically and fixedly connected. The linear velocity of the first cylindrical gear 910 is the same as the linear velocity of the center of the planet gear 820, so that one-stage speed reduction is realized. The first cylindrical gear 910 and the second cylindrical gear 920 have the same angular velocity. The radius of the first cylindrical gear 910 is larger than the radius of the second cylindrical gear 920. The second cylindrical gear 920 is engaged with the third cylindrical gear 930 to realize two-stage speed reduction. The center of the third cylindrical gear 930 is connected to the reduction output end 710 for final output of torque.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-described examples merely represent several embodiments of the present application and are not to be construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A motorized wheel for driving a vehicle frame (200) in motion, comprising:

the wheel hub comprises a rim (101), a spoke (102) and a wheel hub (103), wherein the rim (101) is coaxial with the wheel hub (103), the rim (101) is connected with the wheel hub (103) through the spoke (102), and the wheel hub (103) is arranged opposite to the frame (200);

the suspension guide mechanism comprises a built-in suspension guide mechanism (20), one side of the built-in suspension guide mechanism (20) is connected with the hub (103) through a bearing (106), the other side of the built-in suspension guide mechanism (20) is connected with the frame (200), and the built-in suspension guide mechanism (20) is a four-bar linkage mechanism and is used for damping vertical vibration transmitted to the frame (200) by the hub (103);

and the motor (30) is connected with the built-in suspension guide mechanism (20) and is used for attenuating the vertical vibration transmitted to the motor (30) by the wheel hub (103).

2. The electric wheel of claim 1, further comprising:

and a brake mechanism (50) provided between the hub (103) and the vehicle frame (200).

3. The motorized wheel as defined in claim 2, characterized in that said braking mechanism (50) comprises:

the brake disc (510) is arranged on one side, close to the frame (200), of the hub (103), and the brake disc (510) is coaxially connected with the hub (103);

and a brake caliper (520) provided to the built-in suspension guide mechanism (20) and configured to cooperate with the brake disc (510) to brake.

4. The motorized wheel as set forth in claim 1, wherein said four-bar linkage comprises:

an inner wheel bracket (210) connected to the hub (103) via the bearing (106);

the motor fixing frame (220) is arranged opposite to the built-in wheel bracket (210) at intervals;

one end of the upper swing arm (230) is rotatably connected with the built-in wheel bracket (210), and the other end of the upper swing arm (230) is rotatably connected with the motor fixing frame (220);

and the lower swing arm (240) is arranged opposite to the upper swing arm (230) at intervals, one end of the lower swing arm (240) is rotatably connected with the built-in wheel bracket (210), and the other end of the lower swing arm (240) is rotatably connected with the motor fixing frame (220).

5. The electric wheel of claim 4, further comprising:

and two ends of the vibration damping assembly (40) are respectively and rotatably connected with any two of the electric wheel built-in wheel bracket (210), the motor fixing frame (220), the upper swing arm (230) or the lower swing arm (240).

6. The motorized wheel as set forth in claim 5, wherein the damping assembly (40) comprises:

and two ends of the damping element (410) are respectively and rotatably connected with any two of the built-in wheel bracket (210), the motor fixing frame (220), the upper swing arm (230) or the lower swing arm (240).

7. The motorized wheel as set forth in claim 6, wherein the damping assembly (40) further comprises:

the elastic element (420) is sleeved on the periphery of the damping element (410) and used for synchronously moving with the damping element (410).

8. The motorized wheel according to claim 1, characterized in that said motor (30) comprises an output (310), said motorized wheel (100) further comprising:

a flexible transmission (60) connected between the output end (310) and the hub (103).

9. The motorized trolley wheel according to claim 8, wherein the flexible transmission mechanism (60) comprises a double cross universal transmission mechanism, a rzeppa universal transmission mechanism, a three-fork universal transmission mechanism, a slider flexible transmission mechanism, or a chain transmission mechanism.

10. The electric wheel of claim 9, further comprising:

and the speed reducing mechanism (70) is connected between the output end (310) and the flexible transmission mechanism (60).