Rotation angle measuring device and multi-angle driving vehicle

Abstract

The present invention provides a rotation angle measuring device and a multi-angle driving vehicle, wherein the rotation angle measuring device comprises: a frame, comprising a rotatable central shaft; a gear assembly mechanism, comprising: two second gears and two third gears, the two second gears are coaxially arranged and respectively mesh with the first gear at two different points, each second gear is respectively connected to a third gear in transmission, the two third gears are sleeved on the central shaft and rotate synchronously with the central shaft, and a tensioning member is arranged between the two third gears, and the tension of the tensioning member on each third gear has a component force in the rotation direction of the third gear; an angle measuring instrument, used to measure the rotation angle of the central shaft. The present invention can eliminate the tooth gap between the first gear and the second gear, and between the second gear and the third gear by arranging the tensioning member between the two third gears, and the rotation angle of the gear measured is of high accuracy.

Description

Technical Field

[0001] The present invention relates to the field of transmission and measurement technology, and in particular to a rotation angle measuring device and a multi-angle driving vehicle. Background Art

[0002] Gear transmission is a common transmission structure widely used in the mechanical field. For example, in a multi-angle driving vehicle, the wheel assembly is rotatably connected to the frame, and the two are connected by meshing gears. The motor drives the gear to rotate and drives the wheel assembly to rotate, so as to adjust the driving direction of the vehicle. In order to accurately control the driving direction, it is necessary to accurately measure the rotation angle of the gear to determine whether the wheel assembly has rotated in place.

[0003] In the prior art, when measuring the rotation angle of a gear, as shown in the attached Figure 1 As shown, since there may be tooth gaps between meshing gears during gear transmission, the rotation angles of other gears calculated based on the directly measured rotation angle of the gear may deviate from the actual ones, and the measurement accuracy is poor. Summary of the invention

[0004] The purpose of the present invention is to provide a rotation angle measuring device and a multi-angle driving vehicle, which can solve at least one of the above-mentioned technical problems. The specific solution is as follows:

[0005] According to a specific embodiment of the present invention, in a first aspect, the present invention provides a rotation angle measuring device, comprising:

[0006] A frame including a rotatably arranged central axis;

[0007] A gear assembly mechanism, comprising: two second gears and two third gears, the two second gears are coaxially arranged and meshed with the first gear at two different points respectively, each second gear is respectively connected to one third gear in transmission, the two third gears are sleeved on a central shaft and rotate synchronously with the central shaft, and a tensioning member is arranged between the two third gears, the tension of the tensioning member on each third gear has a component force in the rotation direction of the third gear, so that one second gear is seamlessly meshed with the first gear along the first direction and the other second gear is seamlessly meshed with the first gear along the second direction;

[0008] An angle measuring instrument is arranged on the frame and is used to measure the rotation angle of the central axis.

[0009] Optionally, the angle measuring instrument comprises: a magnetic element and a sensing element, wherein the magnetic element is arranged on the central axis, and the sensing element is arranged on the frame at a position opposite to the central axis.

[0010] Optionally, the frame further comprises: two base plates and a first connecting member;

[0011] The two substrates are arranged opposite to each other at an interval and connected by the first connecting member. Through holes are respectively arranged on the two substrates. Both ends of the central axis are inserted into the through holes and can rotate in the through holes.

[0012] Optionally, the frame further comprises: a rotating shaft, both ends of which are rotatably inserted into the two base plates;

[0013] The gear assembly mechanism further includes: a transmission gear, wherein the transmission gear and the second gear are respectively mounted on the rotating shaft, and a side surface of the transmission gear is fixedly connected to a side surface of the second gear, and the transmission gear is meshed with the third gear.

[0014] Optionally, a transmission ratio of the second gear to the first gear is equal to a transmission ratio of the transmission gear to the third gear.

[0015] Optionally, two ends of the tensioning member are at the same distance from the center of the third gear.

[0016] Optionally, one of the third gears is fixed on the central shaft, and another of the third gears is rotatably mounted on the central shaft, so that the tension of the tensioning member is transmitted to the tooth surface where the first gear and the second gear are in contact through the third gear.

[0017] Optionally, a hollow through hole is provided on the third gear, a connecting head is provided in the through hole, and the end of the tensioning member is connected to the connecting head; the connecting head includes a rope threading part and an anti-slip part, one end of the rope threading part is connected to the inner wall of the through hole, and the anti-slip part is connected to the other end of the rope threading part.

[0018] Optionally, the tensioning member is an elastic member.

[0019] According to a specific embodiment of the present invention, in a second aspect, the present invention provides a multi-angle driving vehicle, comprising any one of the above-mentioned rotation angle measuring devices.

[0020] Compared with the prior art, the embodiments of the present invention have the following technical effects:

[0021] The present invention can further determine the rotation angles of the first gear, the second gear, and the third gear by measuring the rotation angle of the central shaft. Due to the tension generated by the tensioning member between the two third gears, the backlash between the first gear and the second gear, and between the second gear and the third gear can be eliminated, thereby avoiding measurement errors caused by transmission accuracy problems, so that the rotation angles of the first gear, the second gear, and the third gear determined according to the rotation angle of the central shaft have higher accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0023] Figure 1 It is a schematic diagram of two meshing gear structures in the prior art;

[0024] Figure 2 A schematic diagram of the overall structure of a rotation angle measuring device provided by an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of the use status of the rotation angle measuring device provided by an embodiment of the present invention;

[0026] Figure 4 A partial structural schematic diagram of a rotation angle measuring device provided in an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of the partial structure of the third gear in the rotation angle measuring device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0030] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0031] It should be understood that although the terms first, second, third, etc. may be used to describe ... in the embodiments of the present invention, these ... should not be limited to these terms. These terms are only used to distinguish .... For example, without departing from the scope of the embodiments of the present invention, the first ... may also be referred to as the second ..., and similarly, the second ... may also be referred to as the first ....

[0032] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0033] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0034] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] Example 1

[0036] According to a specific embodiment of the present invention, the present invention provides a rotation angle measuring device, as shown in the attached Figure 2 and attached Figure 3 As shown, including:

[0037] The frame 1 includes a rotatable central axis 11;

[0038] The gear assembly mechanism 2 includes: two second gears 22 and two third gears 23. The two second gears 22 are coaxially arranged and meshed with the first gear 21 respectively. Each second gear 22 is respectively connected to a third gear 23 in transmission. The two third gears 23 are sleeved on the central shaft 11 and rotate synchronously with the central shaft 11. A tensioning member 3 is arranged between the two third gears 23. The tension of the tensioning member 3 on each third gear 23 has a component force in the rotation direction of the third gear 23, so that one second gear 22 is seamlessly meshed with the first gear 21 along the first direction and the other second gear 22 is seamlessly meshed with the first gear 21 along the second direction.

[0039] An angle measuring instrument (not shown) is arranged on the frame 1 and is used to measure the rotation angle of the central axis 11 .

[0040] When in use, since the first gear 21 is respectively meshed with the two second gears 22, the two second gears 22 are respectively connected to the two third gears 23, and the two third gears 23 are mounted on the central shaft 11 and rotate synchronously with the central shaft 11. Therefore, the first gear 21, the second gear 22, the third gear 23 and the central shaft 11 are in a synchronous rotation relationship, and the rotation direction and angle are determined by their assembly relationship to have a certain corresponding relationship. The rotation angle of the central shaft 11 is measured by an angle measuring instrument, and the rotation angle of the first gear 21, the second gear 22 and the third gear 23 can be further determined. For example, the transmission relationship can be set so that the first gear 21 and the third gear 23 have the same rotation speed.

[0041] Since a tensioning member 3 is provided between the two third gears 23, the tension generated by the tensioning member 3 has a component force in the rotation direction of the third gear 23, which can make the gear teeth of the third gear 23 and the second gear 22 close to each other when the transmission connection is made. And due to the force transmission relationship, the force in the rotation direction of the third gear 23 can be transmitted to the rotation direction of the second gear 22, so that the gear teeth of the second gear 22 and the first gear 21 are close to each other. That is, through the tension of the tensioning member 3, the tooth gap between the third gear 23 and the second gear 22, and between the first gear 21 and the second gear 22 can be eliminated, and the measurement error caused by the transmission accuracy problem can be avoided, so that the measured rotation angle of the central axis 11 can accurately reflect the rotation angle of the first gear 21, the second gear 22 and the third gear 23.

[0042] In summary, the rotation angle measuring device provided in this embodiment can further determine the rotation angles of the first gear 21, the second gear 22, and the third gear 23 by measuring the rotation angle of the central shaft 11. And due to the tension generated by the tensioning member 3 between the two third gears 23, the tooth gap between the first gear 21 and the second gear 22, and between the second gear 22 and the third gear 23 can be eliminated, and the measurement error caused by the transmission accuracy problem can be avoided, so that the rotation angles of the first gear 21, the second gear 22, and the third gear 23 determined according to the rotation angle of the central shaft 11 have high accuracy.

[0043] Among them, as attached Figure 3 As shown, in the above-mentioned gear assembly mechanism 2 , the two second gears 22 are coaxially arranged and mesh with the first gear 21 respectively, which means that the meshing points of the two second gears 22 and the first gear 21 are two different points on a straight line along the axial direction of the first gear 21 .

[0044] Since the gears rotate synchronously, the first gear 21, any second gear 22 or any third gear 23 can be used as a driving wheel, and the remaining gears are corresponding driven wheels. When in use, a suitable driving wheel can be determined according to the application scenario of the gear assembly mechanism 2, which is not limited in this embodiment. The gear to be tested can also be the first gear 21, any second gear 22 or any third gear 23, etc., which will not be repeated here.

[0045] In actual use, the frame 1 can be set to be fixed and the first gear 21 can be rotatable. Alternatively, the first gear 21 can be set to be fixed and the second gear 22 can make a circular motion around the axis of the first gear 21 during the rotation process, driving the frame 1 as a whole to make a circular motion around the axis of the first gear 21. Those skilled in the art can make settings according to usage requirements.

[0046] In this embodiment, the frame 1 serves as a mounting base for other components, including a rotatable central axis 11. In some optional implementations of this embodiment, such as the attached Figure 2 As shown, the frame 1 also includes: two base plates 12 and a first connecting member 13; the two base plates 12 are arranged opposite to each other and connected by the first connecting member 13, and the two base plates 12 are respectively provided with through holes, and the two ends of the central axis 11 are inserted into the through holes and can rotate in the through holes.

[0047] In this way, the central shaft 11 is located between two base plates 12 that are arranged opposite to each other at a distance, and the base plates 12 limit and protect the central shaft 11. At this time, the third gear 23 sleeved on the central shaft 11 is also located between the two base plates 12.

[0048] Optionally, bearings may be mounted on both ends of the central shaft 11 , which can not only enable the base plate 12 to better limit the ends of the central shaft 11 , but also facilitate the rotation of the central shaft 11 .

[0049] In this embodiment, the first connecting member 13 is arranged between the two substrates 12 to play a connecting role, so that the two substrates 12 maintain a relatively fixed interval. As an example, the first connecting member 13 can be a closed shell that cooperates with the two substrates 12 to form a closed space, thereby fixing the two substrates 12.

[0050] As another example, the first connecting member 13 may be a connecting rod connected between the two substrates 12, and the number of the connecting rods may be multiple and evenly distributed along the circumferential interval. In this example, both ends of the connecting rod may be welded and fixed to the substrate 12. Alternatively, see the attached Figure 2 The middle part of the connecting rod can be a prismatic structure, with bolts at both ends. Corresponding through holes are provided on the substrate 12. The bolts at both ends of the connecting rod pass through the through holes on the substrate 12 and are fastened by nuts. The end face of the prismatic structure in the middle abuts against the surface of the substrate 12, so that the two substrates 12 are detachably connected together.

[0051] In this embodiment, the angle measuring instrument is used to measure the rotation angle of the central axis 11. For example, the angle measuring instrument may be a measuring instrument based on an encoder.

[0052] Alternatively, the angle measuring instrument may be a current sensor. For example, the angle measuring instrument may include a brush head disposed on the central axis 11, and a ring capacitor / resistor disposed outside the central axis 11, the brush head is in contact with the capacitor / resistor, and when the brush head rotates relative to the central axis 11 and the position of contact with the capacitor / resistor changes, the current in the circuit changes, and the rotation angle of the central axis can be determined based on the current change.

[0053] In some optional implementations of this embodiment, the angle measuring instrument may include a magnetic element and a sensing element, wherein the magnetic element is disposed on the central axis 11 , and the sensing element is disposed on the substrate 12 and opposite to the central axis 11 .

[0054] In this configuration, the magnetic element is disposed on the central axis 11, and the inductive element is opposite to the central axis 11 and is located in the magnetic field of the magnetic element. When the central axis 11 rotates, the inductive element generates an induced current according to the rotation of the magnetic field, and the rotation angle of the central axis 11 is determined according to the induced current.

[0055] The magnetic element may be a magnet, a magnetic steel, etc., and the inductive element may be a Hall sensor. It is understood that the angle measuring instrument may further include a processor for receiving the induced current of the inductive element and determining the rotation angle according to the electrical signal. The processor may be independently provided or integrated in the inductive element.

[0056] Furthermore, the rack 1 may also include: a measuring plate and a second connecting member, the measuring plate is arranged opposite to a base plate and connected via the second connecting member. The sensing element may be arranged on the measuring plate and opposite to the central axis 11. The second connecting member may be a closed housing or a connecting rod, etc. The specific arrangement method may refer to the first connecting member 13, which will not be described in detail here.

[0057] In addition, since the measuring board is only used to set the sensing elements, its area can be relatively small. Those skilled in the art can set it according to actual conditions to reduce the occupied space while meeting the measurement requirements.

[0058] In this embodiment, each second gear 22 is transmission-connected to the first third gear 23. As to how to set the transmission mechanism, an optional implementation is given below:

[0059] In some optional implementations of this embodiment, as shown in the attached Figure 2-4As shown, the frame 1 further includes: a rotating shaft 14, both ends of which are rotatably inserted into the two base plates 12. The gear assembly mechanism 2 further includes: a transmission gear 24, the transmission gear 24 and the second gear 23 are respectively sleeved on the rotating shaft 14, and one side of the transmission gear 24 is fixedly connected to one side of the second gear 23, and the transmission gear 24 is meshed with the third gear 23.

[0060] In this arrangement, the second gear 22 and the transmission gear 24 rotate synchronously, and the transmission gear 24 meshes with the third gear 23, so that the third gear 23 is transmission-connected with the second gear 22. When this transmission connection mode is adopted, the tension of the tensioning member 3 on the third gear 23 causes the tooth surfaces of the third gear 23 and the transmission gear 24 to produce a mutual pressing force. The second gear 22 and the transmission gear 24 can be regarded as a whole, and the pressing force on the transmission gear 24 is exerted by the second gear 22 on the first gear 21, so that the tooth surfaces of the first gear 21 and the second gear 22 in contact are pressed against each other.

[0061] In some optional implementations of the present embodiment, the transmission ratio of the second gear 22 to the first gear 21 is equal to the transmission ratio of the transmission gear 24 to the third gear 23, so that the rotation speed of the third gear 23 is equal to the rotation speed of the first gear 21, so that the angle measured by the angle measuring instrument can be directly used as the rotation angle of the first gear 21, simplifying the calculation process.

[0062] Among them, a second gear 22 and a transmission gear 23 are connected together as a whole, and the number of the whole is two. Each of the wholes can be rotatably mounted on the rotating shaft 14, or fixed on the rotating shaft 14.

[0063] Among them, since the rotating shaft 14 is located between the two substrates 12, the second gear 22 and the transmission gear 24 are mounted on the rotating shaft 14 and are also located between the two substrates 12. In order to make the second gear 22 mesh with the first gear 21, the diameter of the second gear 22 can be made larger so that the second gear 22 partially exceeds the outer diameter of the substrate 12. The rotation angle measuring device of this structure has a small thickness and is easy to install and use.

[0064] In some optional implementations of this embodiment, a bearing is provided between the rotating shaft 14 and the base plate 12. In this way, the base plate 12 can limit the rotating shaft 14 and facilitate the rotation of the rotating shaft 14.

[0065] In this embodiment, the tensioning member 3 is used to generate a pulling force between the two third gears 23, and the pulling force has a component in the rotation direction of the third gear 23, that is, the connection points between the two ends of the tensioning member 3 and the third gear 23 cannot be in the same position in the circumferential direction. Figure 3As shown, when in use, the relative positions of the two third gears 23 are adjusted until the tensioning member 3 is tilted, and then the second gear 22 is meshed and assembled with the first gear 21 to achieve a tensioning effect.

[0066] In some optional implementations of this embodiment, the connection points between the two ends of the tensioning member 3 and the third gear 23 are at the same distance from the center of the third gear 23. In this way, the tension of the tensioning member 3 does not have a component force along the radial direction of the third gear 23, eliminating the ineffective torque inside the device.

[0067] In some optional implementations of this embodiment, one third gear 23 is fixed on the central shaft 11 , and another third gear 23 is rotatably mounted on the central shaft 11 .

[0068] First, it should be understood that there may be no direct constraint between the two third gears 23, and the synchronous rotation of the two third gears 23 can be maintained by the transmission connection between the two third gears 23 and the synchronously rotating second gears 22. Since in this embodiment, the two third gears 23 rotate synchronously with the central shaft 11, at least one of the two third gears 23 should be fixed on the central shaft 11. If the two third gears 23 are both fixed on the central shaft 11, the two third gears 23 and the central shaft 11 can be regarded as a whole, and the tension force inside the whole has little effect on the outside. Therefore, in this embodiment, one third gear 23 is fixed on the central shaft 11, and the other third gear 23 is rotatably mounted on the central shaft 11, so that the tension of the tensioning member 3 can fully play a role in the entire gear assembly mechanism 2, reducing or eliminating the tooth gap between the gears.

[0069] Correspondingly, a second gear 22 and a transmission gear 23 form an integral body, the number of the integral bodies is two, and at least one of the integral bodies is rotatably mounted on the rotating shaft 14 .

[0070] In this embodiment, the tensioning member 3 can be a steel wire rope, etc., as long as it can play a tensioning role. The number of tensioning members 3 can be multiple, and multiple tensioning members 3 can be evenly distributed along the circumference of the third gear 23, so that the third gear 23 is evenly stressed and the tensioning effect is improved.

[0071] In this embodiment, as shown in the attached Figure 5 As shown, in order to facilitate the connection of the tensioning member 3 to the third gear 23, a hollow through hole is provided at the position connected to the tensioning member 3 on the third gear 23, and a connector 231 is provided in the through hole. The connector 231 includes a rope threading portion and an anti-slip portion located at the end of the rope threading portion. The anti-slip portion is an arc-shaped structure with a large area and facing the rope threading portion, which blocks the end of the tensioning member 3 from falling off. For example, when the tensioning member 3 is a steel wire rope, its rope end can be tied to the rope threading portion.

[0072] Example 2

[0073] The same structures as those in Example 1 in this embodiment are not described in detail. The same structural parts have the same technical effects and are not described in detail. According to the specific implementation of the present invention, in the rotation angle measuring device provided in this embodiment, the tensioning member 3 is an elastic member. With such an arrangement, the tension of the tensioning member 3 can be more conveniently controlled by the degree of elongation of the tensioning member 3. In this way, before use, the position of the rotatable third gear 23 can be pre-adjusted and then the meshing assembly can be completed to obtain different tensioning forces. When adjusting the tensioning force, the meshing between the first gear 21 and the second gear 22 is released, and the second gear 22 and / or the third gear 23 are rotated until the tensioning member 3 is elongated to a preset length and then the two second gears 22 are meshed with the first gear 21, so that the adjustment process can be completed conveniently.

[0074] Correspondingly, a second gear 22 and a transmission gear 23 are an integral body, the number of the integral bodies is two, and at least one of the integral bodies is rotatably mounted on the rotating shaft 14 .

[0075] The elastic member may be a spring or an elastic band, etc., which is not limited in this embodiment. For example, when the elastic member is a spring, the hook at the end of the spring may be hung on the rope threading portion of the connector 231 .

[0076] It can be seen that the rotation angle measuring device provided in this embodiment eliminates the backlash during gear transmission, and the rotation angles of the first gear 21, the second gear 22 and the third gear 23 can be determined more accurately by measuring the rotation angle of the central shaft 11. Moreover, the tensioning member 3 is set as an elastic member to cooperate with the relative rotation between the two third gears 23, so that the tension can be controlled more conveniently.

[0077] Example 3

[0078] The same structures as those in Embodiment 1 or 2 are not described in detail here, and the same structural parts have the same technical effects and are not described in detail here. According to a specific embodiment of the present invention, the present invention provides a multi-angle driving vehicle, including any rotation angle measuring device as described above.

[0079] In some optional implementations of this embodiment, the multi-angle driving vehicle may further include: a frame, a plurality of wheel assemblies respectively arranged around the frame, the wheel assemblies are rotatably connected to the frame, and the two are connected by meshing gears, the motor drives the gears to rotate and then drives the wheel assemblies to rotate, so as to achieve the purpose of adjusting the driving direction of the vehicle. The gears driven by the motor to rotate and then drive the wheel assemblies to rotate can be used as the first gear 21 in the rotation angle measuring device. After the rotation angle of the rotating shaft is measured by the angle measuring instrument, the rotation angle of the first gear 21 can be determined according to the transmission relationship between the first gear 21 and the central shaft 11, and then the rotation angle of the wheel assembly can be determined, so as to accurately control the driving direction of the vehicle.

[0080] In summary, the multi-angle driving vehicle provided in this embodiment can accurately measure the rotation angle of the wheel assembly by setting the above-mentioned rotation angle measuring device, thereby accurately controlling the driving direction of the vehicle.

[0081] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other. For the system or device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0082] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A rotation angle measuring device, characterized in that: include: A frame including a rotatably arranged central axis; A gear assembly mechanism, comprising: two second gears and two third gears, the two second gears are coaxially arranged and meshed with the first gear at two different points respectively, each second gear is respectively connected to one third gear in transmission, the two third gears are sleeved on a central shaft and rotate synchronously with the central shaft, and a tensioning member is arranged between the two third gears, the tension of the tensioning member on each third gear has a component force in the rotation direction of the third gear, so that one second gear is seamlessly meshed with the first gear along the first direction and the other second gear is seamlessly meshed with the first gear along the second direction; An angle measuring instrument, arranged on the frame, for measuring the rotation angle of the central axis, The connection points between the two ends of the tensioning member and the third gear cannot be at the same position in the circumferential direction; the connection points between the two ends of the tensioning member and the third gear are at the same distance from the center of the third gear.

2. The device according to claim 1, characterized in that The angle measuring instrument comprises: a magnetic element and a sensing element. The magnetic element is arranged on the central axis, and the sensing element is arranged on the frame at a position opposite to the central axis.

3. The device according to claim 1, characterized in that The frame further comprises: two base plates and a first connecting member; The two substrates are arranged opposite to each other at an interval and connected by the first connecting member. Through holes are respectively arranged on the two substrates. Both ends of the central axis are inserted into the through holes and can rotate in the through holes.

4. The device according to claim 3, characterized in that The frame further comprises: a rotating shaft, both ends of which are rotatably inserted into the two base plates; The gear assembly mechanism further includes: a transmission gear, wherein the transmission gear and the second gear are respectively mounted on the rotating shaft, and a side surface of the transmission gear is fixedly connected to a side surface of the second gear, and the transmission gear is meshed with the third gear.

5. The device according to claim 4, characterized in that A transmission ratio of the second gear to the first gear is equal to a transmission ratio of the transmission gear to the third gear.

6. The device according to claim 1, characterized in that One of the third gears is fixed on the central shaft, and the other third gear is rotatably mounted on the central shaft, so that the tension of the tensioning member is transmitted to the tooth surface where the first gear and the second gear contact through the third gear.

7. The device according to claim 1, characterized in that The third gear is provided with a hollow through hole, a connector is provided in the through hole, and the end of the tensioning member is connected to the connector; The connector includes a rope threading portion and an anti-slip portion, one end of the rope threading portion is connected to the inner wall of the through hole, and the anti-slip portion is connected to the other end of the rope threading portion.

8. The device according to any one of claims 1 to 7, characterized in that: The tensioning member is an elastic member.

9. A multi-angle driving vehicle, characterized in that: The invention comprises the rotation angle measuring device according to any one of claims 1 to 8.

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