Planetary transmission mechanism and gearbox

Abstract

The present invention belongs to the technical field of wind power gearboxes, and discloses a planetary transmission mechanism and a gearbox. The planetary transmission mechanism includes a planetary carrier, a pin shaft, a planetary wheel and a follower assembly, wherein the pin shaft is rotatably arranged on the planetary carrier, and a sliding bearing is arranged on the pin shaft; the planetary wheel is sleeved on the sliding bearing and has a clearance fit with the sliding bearing; the follower assembly is arranged between the planetary carrier and the pin shaft, and the follower assembly has a connected state and a disconnected state; when the follower assembly is in the connected state, the pin shaft is fixedly connected to the planetary carrier, and the planetary wheel rotates relative to the pin shaft; when the follower assembly is in the disconnected state, the pin shaft rotates relative to the planetary carrier, and the planetary wheel and the pin shaft rotate synchronously. The gearbox includes the above-mentioned planetary transmission mechanism, and can continue to operate in the event of internal lubrication failure to ensure the normal operation of the wind turbine generator set, greatly reducing the power generation loss of the wind turbine generator set.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power gearboxes, and in particular to a planetary transmission mechanism and a gearbox. Background Art

[0002] In wind turbines, gearboxes are key components of wind turbines. Currently, the gearboxes of wind turbines generally contain one or more planetary speed stages, and the planetary gears in the planetary mechanism usually use sliding bearings to rotate with the planetary carrier. However, during the use of sliding bearings, it is easy for bearings to overheat and bearings to burn out. At this time, the wind turbine gearbox cannot operate normally due to the failure of the planetary mechanism. The staff needs to repair or replace the gearbox immediately, which will cause the loss of power generation of the entire wind turbine, and in an emergency, it will also affect the regional power supply capacity.

[0003] Therefore, it is urgent to design a gearbox to solve the above technical problems existing in the prior art. Summary of the invention

[0004] The object of the present invention is to provide a planetary transmission mechanism and a gear box, which can operate normally under the condition of insufficient lubrication to reduce the loss of power generation.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] Planet carrier;

[0007] A pin shaft, the pin shaft is rotatably arranged on the planet carrier, and a sliding bearing is arranged on the pin shaft;

[0008] A planetary gear, wherein the planetary gear is sleeved on the sliding bearing;

[0009] A follower assembly, the follower assembly is arranged between the planet carrier and the pin shaft, and the follower assembly has a connected state and a disconnected state;

[0010] When the follower assembly is in the connected state, the pin shaft is fixedly connected to the planetary carrier, and the planetary wheel rotates relative to the pin shaft; when the follower assembly is in the disconnected state, the pin shaft rotates relative to the planetary carrier, and the planetary wheel and the pin shaft rotate synchronously.

[0011] Preferably, the follower assembly comprises a first follower portion and a second follower portion, wherein the first follower portion is connected to the planet carrier, and the second follower portion is connected to the pin shaft;

[0012] When the follower assembly is in the connected state, the first follower part is connected to the second follower part; when the follower assembly is in the disconnected state, the first follower part is disconnected from the second follower part.

[0013] Preferably, when the follower assembly is in the disconnected state, the friction force between the pin shaft and the planetary gear is greater than the friction force between the planetary carrier and the pin shaft.

[0014] Preferably, the follower assembly further comprises an elastic member, the first follower portion comprises a first abutment pin, the second follower portion comprises a second abutment pin, the first abutment pin is connected to the planet carrier via the elastic member, the second abutment pin is connected to the pin shaft, and when the follower assembly is in the connected state, the first abutment pin abuts against the second abutment pin in the opposite direction of rotation of the planetary gear under the elastic force of the elastic member;

[0015] Alternatively, the second abutment pin is connected to the pin shaft through the elastic member, and the first abutment pin is connected to the planetary carrier. When the follower assembly is in the connected state, the second abutment pin abuts against the first abutment pin along the direction of rotation of the planetary gear under the elastic force of the elastic member.

[0016] Preferably, the pressure between the second abutment pin and the first abutment pin is F1, the elastic force of the elastic member on the first abutment pin or the second abutment pin is T, the friction force between the planetary carrier and the pin shaft is F2, and when F1>F2+T, the follower assembly switches to the disconnected state, and the second abutment pin disengages from the first abutment pin along the rotation direction of the planetary gear.

[0017] Preferably, the follower assembly also includes a shear pin, both ends of which are respectively connected to the first follower part and the second follower part, the first follower part is connected to the planetary carrier, and the second follower part is connected to the pin shaft, and when the shear pin is sheared off under the torque of the pin shaft, the first follower part and the second follower part are disconnected.

[0018] Preferably, a diameter of the shear pin is smaller than a diameter of the first follower portion and smaller than a diameter of the second follower portion.

[0019] Preferably, the pin shaft is arranged in the pin hole of the planetary carrier, and an oil storage cavity is arranged on the inner wall of the pin hole, and the oil storage cavity is used to transport lubricating oil to the outer peripheral surface of the pin shaft;

[0020] A first accommodating cavity is provided on the inner wall of the pin hole of the planetary carrier, a second accommodating cavity is concavely provided on the outer circumferential surface of the pin shaft, two ends of the follower assembly are respectively arranged in the first accommodating cavity and the second accommodating cavity, and the first accommodating cavity is communicated with the oil storage cavity.

[0021] Preferably, the oil storage chamber is connected to the oil inlet channel of the planet carrier;

[0022] The pin shaft has a lubricating oil circuit inside, and the lubricating oil circuit is used to transport lubricating oil to the sliding bearing, and the oil storage chamber is connected to the lubricating oil circuit.

[0023] The gear box comprises a box body and the above-mentioned planetary transmission mechanism, wherein the planetary transmission mechanism is arranged in the box body.

[0024] The beneficial effects of the present invention are:

[0025] The planetary transmission mechanism provided by the present invention has a pin shaft arranged on a planetary carrier, a sliding bearing arranged on the pin shaft, and a planetary wheel sleeved on the sliding bearing, so that the planetary wheel can rotate relative to the planetary carrier and the pin shaft to achieve normal transmission operation; a follower assembly is arranged between the planetary carrier and the pin shaft, and when the follower assembly is in a connected state, the planetary wheel rotates normally relative to the pin shaft, thereby achieving normal transmission operation; when the sliding bearing on the pin shaft overheats or other failures occur, causing the sliding bearing and the planetary wheel to lock, the follower assembly switches to a disconnected state, at which time the planetary wheel drives the pin shaft to continue to rotate synchronously relative to the planetary carrier, thereby avoiding the planetary transmission mechanism from getting stuck and being unable to continue to operate, thereby ensuring that the gear box can operate normally in a short period of time, and also providing sufficient preparation time for repairing and replacing the planetary transmission mechanism.

[0026] The gearbox provided by the present invention comprises a housing and the above-mentioned planetary transmission mechanism. The gearbox can continue to operate when the internal lubrication of the planetary transmission mechanism fails, and can maintain normal transmission operation in a short period of time to ensure the normal operation of the wind turbine generator set, greatly reducing the power generation loss of the wind turbine generator set, and also providing sufficient preparation time for repairing and replacing the planetary transmission mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a cross-sectional view of a planetary transmission mechanism provided in a specific embodiment of the present invention;

[0028] Figure 2 is a schematic structural diagram of a follower assembly provided in Embodiment 1 of the present invention;

[0029] Figure 3 It is a schematic diagram of the structure of the follower assembly provided in the second embodiment of the present invention.

[0030] In the figure:

[0031] 1-planet carrier; 11-oil storage chamber; 12-oil inlet channel;

[0032] 2-pin shaft; 21-wear-resistant layer; 22-sliding bearing; 23-lubricating oil circuit;

[0033] 3-Planetary gear;

[0034] 4-follower assembly; 41-first follower; 411-first abutment pin; 412-elastic member; 42-second follower; 43-shear pin. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0036] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0038] In the description of this embodiment, the terms "upper", "lower", "right", "left" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0039] like Figures 1 to 3As shown, the present application provides a planetary transmission mechanism, which includes a planetary carrier 1, a pin shaft 2, a planetary wheel 3 and a follower assembly 4, the pin shaft 2 is rotatably arranged on the planetary carrier 1, and a sliding bearing 22 is arranged on the pin shaft 2; the planetary wheel 3 is sleeved on the sliding bearing 22 and has a clearance fit with the sliding bearing 22 (in other embodiments, the sliding bearing 22 may also have an interference fit with the planetary wheel 3 and a clearance fit with the pin shaft 2, which is not described in detail here); the follower assembly 4 is arranged between the planetary carrier 1 and the pin shaft 2, and the follower assembly 4 has a connected state and a disconnected state; when the follower assembly 4 is in the connected state, the pin shaft 2 is fixedly connected to the planetary carrier 1, and the planetary wheel 3 rotates relative to the pin shaft 2; when the follower assembly 4 is in the disconnected state, the pin shaft 2 rotates relative to the planetary carrier 1, and the planetary wheel 3 and the pin shaft 2 rotate synchronously. In this embodiment, a sliding bearing 22 is provided on the pin shaft 2, and the planetary wheel 3 and the sliding bearing 22 are clearance-matched, so the planetary wheel 3 can rotate relative to the planetary carrier 1 and the pin shaft 2 to achieve normal transmission operation, and the sliding bearing 22 reduces the friction between the planetary wheel 3 and the pin shaft 2; when the follower assembly 4 is in a connected state, the planetary wheel 3 can rotate normally relative to the pin shaft 2, thereby achieving normal transmission operation; when the sliding bearing 22 on the pin shaft 2 overheats or other failures occur, causing the sliding bearing 22 and the planetary wheel 3 to lock, the follower assembly 4 switches to a disconnected state, at which time the planetary wheel 3 can drive the pin shaft 2 to continue to rotate synchronously relative to the planetary carrier 1, avoiding the planetary transmission mechanism from getting stuck and unable to continue to operate, thereby ensuring that the gearbox can operate normally in a short period of time, and also providing sufficient preparation time for repairing and replacing the planetary transmission mechanism.

[0040] Different states of the follower assembly 4 correspond to different operating conditions of the planetary transmission mechanism. When the planetary gear 3 rotates relative to the pin shaft 2, the planetary transmission mechanism is in a normal working condition, and the corresponding follower assembly 4 is in a connected state. At this time, the planetary transmission mechanism operates according to the designed working condition; when the pin shaft 2 is locked with the planetary gear 3 due to overheating, the pin shaft 2 is driven by the planetary gear 3 and rotates synchronously with the planetary gear 3 relative to the planetary carrier 1. The planetary transmission mechanism is in an emergency condition, and the corresponding follower assembly 4 is in a disconnected state. At this time, the planetary transmission mechanism does not operate according to the designed working condition, but can ensure the overall operation and output of the gear box in a short period of time, and also provide sufficient preparation time for repairing and replacing the planetary transmission mechanism.

[0041] The structure of the follower assembly 4 can be set according to actual needs, as long as the switching between the connected state and the disconnected state can be realized. Exemplarily, the follower assembly 4 has a first follower part 41 and a second follower part 42, the first follower part 41 is connected to the planet carrier 1, and the second follower part 42 is connected to the pin 2; when the follower assembly 4 is in the connected state, the first follower part 41 and the second follower part 42 are connected; when the follower assembly 4 is in the disconnected state, the first follower part 41 and the second follower part 42 are disconnected. It can be understood that when the follower assembly 4 is in the connected state, the planet carrier 1 is fixed to the pin 2 through the connection between the first follower part 41 and the second follower part 42, so the pin 2 cannot rotate relative to the planet carrier 1; when the follower assembly 4 is in the disconnected state, the connection between the planet carrier 1 and the pin 2 is disconnected, so the pin 2 can rotate relative to the planet carrier 1 driven by the planetary gear 3.

[0042] like Figure 1 As shown, in order to install the pin shaft 2 more stably and conveniently, for example, a pin hole is provided on the planetary carrier 1, and the pin shaft 2 is inserted into the pin hole of the planetary carrier 1 with interference fit, and the inner wall of the pin hole is in contact with the outer peripheral surface of the pin shaft 2. The inner wall of the pin hole is provided with an oil storage chamber 11, and the oil storage chamber 11 is used to transport lubricating oil to the outer peripheral surface of the pin shaft 2, so that the outer peripheral surface of the pin shaft 2 and the inner wall of the pin hole can be lubricated to reduce the friction force when the pin shaft 2 rotates relative to the planetary carrier 1, and ensure that the pin shaft 2 can rotate smoothly when the follower assembly 4 is in a disconnected state. Specifically, the pin shaft 2 includes a wear-resistant layer 21, and the outer wall surface of the wear-resistant layer 21 is the outer peripheral surface of the pin shaft 2. The wear-resistant layer 21 has high lubricity and good wear resistance, and can further reduce the sliding friction between the pin shaft 2 and the planetary carrier 1. In this embodiment, the wear-resistant layer 21 is made of polytetrafluoroethylene.

[0043] Furthermore, a first accommodating chamber is provided on the inner wall of the pin hole of the planet carrier 1, a second accommodating chamber is recessed on the outer circumferential surface of the pin shaft 2, and both ends of the follower assembly 4 are respectively provided in the first accommodating chamber and the second accommodating chamber, and the first accommodating chamber is communicated with the oil storage chamber 11, so that part of the lubricating oil entering the oil storage chamber 11 enters the first accommodating chamber, and when the follower assembly 4 is in a disconnected state, the lubricating oil can timely lubricate the follower assembly 4 between the first accommodating chamber and the second accommodating chamber and the surface of the follower assembly 4 after disconnection, so that when the follower assembly 4 is in a disconnected state, the pin shaft 2 can rotate more smoothly relative to the planet carrier 1. Exemplarily, the first accommodating chamber is recessed on the inner wall of the oil storage chamber 11 along the radial direction of the pin hole.

[0044] Furthermore, a lubricating oil circuit 23 is provided inside the pin shaft 2, and an oil inlet channel 12 is opened on the planetary carrier 1. The lubricating oil circuit 23 is used to transport lubricating oil to the sliding bearing 22. The oil inlet channel 12 is connected to the lubricating oil circuit 23 through the oil storage chamber 11; and the lubricating oil circuit 23 passes through the pin shaft 2 and the wear-resistant layer 21 and is connected to the oil storage chamber 11. When the follower component 4 is in a connected state, part of the lubricating oil in the oil inlet channel 12 is stored in the oil storage chamber 11, and part of it flows into the lubricating oil circuit 23, thereby realizing lubrication of the sliding bearing 22; when the follower component 4 is in a disconnected state, the lubricating oil in the oil storage chamber 11 lubricates the disconnected follower component 4 and the surface of the follower component 4 after disconnection.

[0045] Furthermore, a plurality of follower assemblies 4 are provided along the axial direction of the pin shaft 2 to ensure the connection stability and connection strength between the pin shaft 2 and the planetary carrier 1 when the planetary transmission mechanism is in normal working condition.

[0046] This embodiment also provides a gearbox, which includes a box body and the above-mentioned planetary transmission mechanism, and the planetary transmission mechanism is arranged in the box body; a sun gear is also arranged in the gearbox, and the sun gear meshes with the planetary gear 3 and drives the planetary gear 3 to rotate, thereby realizing high-speed transmission of the gearbox.

[0047] In this embodiment, the gearbox can continue to operate when the internal lubrication of the planetary transmission mechanism fails, and can maintain normal transmission operation in a short period of time to ensure the normal operation of the wind turbine generator set, greatly reducing the power generation loss of the wind turbine generator set, and also providing sufficient preparation time for repairing and replacing the planetary transmission mechanism.

[0048] Embodiment 1

[0049] For example, Figure 2 As shown, the follower assembly 4 also includes an elastic member 412, the first follower portion 41 includes a first abutment pin 411, the second follower portion 42 includes a second abutment pin, the first abutment pin 411 is connected to the planetary carrier 1 through the elastic member 412, and the second abutment pin is connected to the pin shaft 2; when the follower assembly 4 is in a connected state, the first abutment pin 411 abuts against the second abutment pin in the opposite direction of rotation of the planetary gear 3 under the elastic force of the elastic member 412; in another embodiment, the elastic member 412 is connected to the second abutment pin, the second abutment pin is connected to the pin shaft 2 through the elastic member 412, and the first abutment pin 411 is connected to the planetary carrier 1, and when the follower assembly 4 is in a connected state, the second abutment pin abuts against the first abutment pin 411 in the direction of rotation of the planetary gear 3 under the elastic force of the elastic member 412.

[0050] Specifically, the first abutting pin 411 has a first abutting inclined surface, and the second abutting pin has a second abutting inclined surface matched with the first abutting inclined surface. When the follower assembly 4 is in a connected state, the first abutting pin 411 abuts against the second abutting pin under the elastic force of the elastic member 412, so that the second abutting inclined surface pushes against the first abutting inclined surface along the rotation direction of the planetary gear 3. In this embodiment, the first abutting inclined surface can play a fixing role on the pin shaft 2 by pushing against the second abutting inclined surface, preventing the pin shaft 2 from being driven by the planetary gear 3 to rotate under normal working conditions of the planetary transmission mechanism, thereby ensuring the stability of the pin shaft 2; the elastic member 412 is a compression spring, and the elastic member 412, the first abutting pin 411 and the second abutting pin are all arranged along the radial direction of the pin shaft 2, and the first abutting pin 411 can abut against the second abutting pin under the elastic force of the elastic member 412. In another embodiment, a first toothed concave-convex surface is provided on the end surface where the first abutment pin 411 abuts against the second abutment pin, and a second toothed concave-convex surface matching the first toothed concave-convex surface is provided on the end surface of the second abutment pin; when the follower assembly 4 is in a connected state, the first toothed concave-convex surface is meshed with the second toothed concave-convex surface, thereby ensuring the relative fixation of the pin shaft 2 and the planetary carrier 1.

[0051] In order to prevent the pin shaft 2 from rotating relative to the planetary carrier 1 under normal operating conditions of the planetary transmission mechanism, when the follower assembly 4 is in a connected state, the pressure F1 between the first abutment pin 411 and the second abutment pin is less than the sum of the elastic force T of the elastic member 412 and the friction force F2 between the planetary carrier 1 and the pin shaft 2. At this time, the second abutment pin cannot push the first abutment pin 411, so the second abutment pin is always in contact with the first abutment pin 411, thereby ensuring the stability of the pin shaft 2; when F1>F2+T, the follower assembly 4 switches to a disconnected state, and the second abutment pin disengages from the first abutment pin 411 along the rotation direction of the planetary gear 3.

[0052] Specifically, the elastic member 412 is arranged in the first accommodating chamber, the second abutment pin is arranged in the second accommodating chamber, the first abutment pin 411 and the second abutment pin abut in the oil storage chamber 11, and the two ends of the elastic member 412 are respectively connected to the bottom surface of the first accommodating chamber and the first abutment pin 411, and the first abutment pin 411 can compress the elastic member 412 to retract into the accommodating chamber under the action of the second abutment pin; when the follower assembly 4 is in a connected state, the first abutment pin 411 extends out of the first accommodating chamber and abuts against the second abutment pin under the elastic force of the elastic member 412, and when the pin shaft 2 locks with the planetary gear 3 due to overheating, the second abutment pin pushes the first abutment pin 411, so that the first abutment pin 411 compresses the elastic member 412 and retracts into the accommodating chamber, and at this time the follower assembly 4 switches to a disconnected state.

[0053] It can be understood that when the follower assembly 4 is in a connected state, the first abutment pin 411 can be fully extended from the first accommodating chamber and located in the oil storage chamber 11, or can be partially extended from the first accommodating chamber and located in the oil storage chamber 11; when the first abutment pin 411 is fully extended from the first accommodating chamber, the elastic member 412 is rigidly connected to the first abutment pin 411, thereby ensuring that the first abutment pin 411 is stably retracted into the first accommodating chamber along the radial direction of the pin shaft 2.

[0054] In another embodiment, the elastic member 412 is disposed in the second accommodating chamber, and when the follower assembly 4 is in the disconnected state, the second abutting pin can compress the elastic member 412 under the action of the first abutting pin 411 to retract into the second accommodating chamber; wherein the second abutting pin can be fully extended from the second accommodating chamber or partially extended from the second accommodating chamber when the follower assembly 4 is in the connected state, as long as it is ensured that the second abutting pin is rigidly connected to the elastic member 412 when it is fully extended from the second accommodating chamber. Specifically, since the first abutting pin 411 and the second abutting pin abut against the oil storage chamber 11, the first abutting pin 411 and the second abutting pin can be lubricated by the lubricating oil in the oil storage chamber 11, thereby reducing the friction force when the end face of the first abutting pin 411 and the end face of the second abutting pin are subsequently in contact, so that the pin shaft 2 can rotate more smoothly relative to the planetary carrier 1.

[0055] Furthermore, in order to ensure that the pin shaft 2 can rotate smoothly relative to the planetary carrier 1 under the drive of the planetary gear 3, when the follower assembly 4 is in the disconnected state, the friction between the pin shaft 2 and the planetary gear 3 is greater than the friction between the planetary carrier 1 and the pin shaft 2, so that the planetary gear 3 can drive the pin shaft 2 to overcome the friction brought by the planetary carrier 1 and rotate, thereby preventing slipping.

[0056] The present embodiment also provides a planetary transmission method, which adopts the above-mentioned planetary transmission mechanism, including: during normal transmission, the follower assembly 4 is in a connected state, the pin shaft 2 is fixedly connected to the planetary carrier 1, and the planetary wheel 3 rotates around the pin shaft 2; in this case, the pressure F1 between the first abutment pin 411 and the second abutment pin is less than the sum of the elastic force T of the elastic member 412 and the friction force F2 between the planetary carrier 1 and the pin shaft 2, that is, F1<F2+T, wherein the pressure F1 between the first abutment pin 411 and the second abutment pin is generated by the friction force between the planetary wheel 3 and the sliding bearing 22, and the planetary transmission mechanism is in a normal working condition.

[0057] When the sliding bearing 22 fails and causes the planetary gear 3 and the pin shaft 2 to lock, the friction between the planetary gear 3 and the sliding bearing 22 increases sharply, and F1>F2+T, then the first abutment pin 411 is lifted up by the second abutment pin and disengaged from the abutment with the second abutment pin, the follower assembly 4 switches to the disconnected state, the pin shaft 2 rotates relative to the planetary carrier 1, the planetary gear 3 and the pin shaft 2 rotate synchronously relative to the planetary carrier 1, and the planetary transmission mechanism is in an emergency working condition.

[0058] Embodiment 2

[0059] like Figure 1 and Figure 3 As shown, this embodiment provides a planetary transmission mechanism, which is basically the same as the planetary transmission mechanism in the first embodiment, and the main difference is that: in this embodiment, the follower assembly 4 also includes a shear pin 43, and the two ends of the shear pin 43 are respectively connected to the first follower part 41 and the second follower part 42, the first follower part 41 is fixedly connected to the planet carrier 1, and the second follower part 42 is fixedly connected to the pin shaft 2. When the shear pin 43 is sheared off under the torque of the pin shaft 2, the first follower part 41 and the second follower part 42 are disconnected. Specifically, the first follower part 41 is arranged in the first accommodating cavity, and the second follower part 42 is arranged in the second accommodating cavity. The shear pin 43 is a commonly used connection accessory in the art. When the reverse torque applied to the two ends exceeds a certain value, the shear pin 43 will break.

[0060] Furthermore, the diameter of the shear pin 43 is smaller than the diameter of the first follower portion 41 and smaller than the diameter of the second follower portion 42 , so that the shear pin 43 is easier to be sheared without damaging the first follower portion 41 and the second follower portion 42 .

[0061] During normal transmission, the follower assembly 4 is in a connected state, the pin 2 is fixedly connected to the planetary carrier 1, and the planetary gear 3 rotates around the pin 2; in this case, the second follower part 42 will generate a shear force relative to the first follower part 41, and the shear force is generated by the friction between the planetary gear 3 and the sliding bearing 22. The shear force is much smaller than the sum of the shear resistance of the shear pin 43 and the friction between the planetary carrier 1 and the pin 2. At this time, the planetary transmission mechanism is in a normal working condition.

[0062] When the sliding bearing 22 fails and causes the planetary gear 3 and the pin shaft 2 to lock, the friction force between the planetary gear 3 and the sliding bearing 22 increases sharply, causing the shear force of the second follower part 42 relative to the first follower part 41 to increase accordingly, and the shear pin 43 is sheared off, and the follower assembly 4 switches to the disconnected state, the pin shaft 2 rotates relative to the planetary carrier 1, and the planetary gear 3 and the pin shaft 2 rotate synchronously relative to the planetary carrier 1. At this time, the planetary transmission mechanism is in an emergency working condition.

[0063] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A planetary transmission mechanism, characterized in that: include: Planet carrier (1); A pin shaft (2), the pin shaft (2) being rotatably arranged on the planet carrier (1), and a sliding bearing (22) being arranged on the pin shaft (2); A planetary gear (3), the planetary gear (3) being sleeved on the sliding bearing (22); A follower assembly (4), the follower assembly (4) being arranged between the planet carrier (1) and the pin shaft (2), the follower assembly (4) having a connected state and a disconnected state; When the follower assembly (4) is in the connected state, the pin shaft (2) is fixedly connected to the planet carrier (1), and the planetary wheel (3) rotates relative to the pin shaft (2); when the follower assembly (4) is in the disconnected state, the pin shaft (2) rotates relative to the planet carrier (1), and the planetary wheel (3) and the pin shaft (2) rotate synchronously.

2. The planetary transmission mechanism according to claim 1, characterized in that: The follower assembly (4) comprises a first follower part (41) and a second follower part (42), wherein the first follower part (41) is connected to the planet carrier (1), and the second follower part (42) is connected to the pin shaft (2); When the follower assembly (4) is in the connected state, the first follower part (41) and the second follower part (42) are connected; when the follower assembly (4) is in the disconnected state, the first follower part (41) and the second follower part (42) are disconnected.

3. The planetary transmission mechanism according to claim 1, characterized in that: When the follower assembly (4) is in the disconnected state, the friction force between the pin shaft (2) and the planetary wheel (3) is greater than the friction force between the planetary carrier (1) and the pin shaft (2).

4. The planetary transmission mechanism according to claim 2, characterized in that: The follower assembly (4) further comprises an elastic member (412), the first follower portion (41) comprises a first abutment pin (411), the second follower portion (42) comprises a second abutment pin, the first abutment pin (411) is connected to the planet carrier (1) via the elastic member (412), the second abutment pin is connected to the pin shaft (2), and when the follower assembly (4) is in the connected state, the first abutment pin (411) abuts against the second abutment pin in the opposite direction of rotation of the planetary gear (3) under the elastic force of the elastic member (412); Alternatively, the second abutment pin is connected to the pin shaft (2) via the elastic member (412), and the first abutment pin (411) is connected to the planetary carrier (1); when the follower assembly (4) is in the connected state, the second abutment pin abuts against the first abutment pin (411) along the direction of rotation of the planetary gear (3) under the action of the elastic force of the elastic member (412).

5. The planetary transmission mechanism according to claim 4, characterized in that: The pressure between the second abutment pin and the first abutment pin (411) is F1, the elastic force of the elastic member (412) on the first abutment pin (411) or the second abutment pin is T, and the friction force between the planet carrier (1) and the pin shaft (2) is F2. When F1>F2+T, the follower assembly (4) switches to the disconnected state, and the second abutment pin disengages from the first abutment pin (411) along the rotation direction of the planetary gear (3).

6. The planetary transmission mechanism according to claim 2, characterized in that: The follower assembly (4) further comprises a shear pin (43), the two ends of the shear pin (43) being respectively connected to the first follower part (41) and the second follower part (42), the first follower part (41) being connected to the planet carrier (1), and the second follower part (42) being connected to the pin shaft (2), and when the shear pin (43) is sheared off under the action of the torque of the pin shaft (2), the first follower part (41) and the second follower part (42) are disconnected.

7. The planetary transmission mechanism according to claim 6, characterized in that: The diameter of the shear pin (43) is smaller than the diameter of the first follower part (41) and smaller than the diameter of the second follower part (42).

8. The planetary transmission mechanism according to claim 1, characterized in that: The pin shaft (2) is arranged in a pin hole of the planet carrier (1), and an oil storage cavity (11) is arranged on the inner wall of the pin hole, and the oil storage cavity (11) is used to transport lubricating oil to the outer peripheral surface of the pin shaft (2); A first accommodating cavity is provided on the inner wall of the pin hole of the planet carrier (1), a second accommodating cavity is concavely provided on the outer peripheral surface of the pin shaft (2), two ends of the follower assembly (4) are respectively arranged in the first accommodating cavity and the second accommodating cavity, and the first accommodating cavity is communicated with the oil storage cavity (11).

9. The planetary transmission mechanism according to claim 8, characterized in that: The oil storage chamber (11) is connected to the oil inlet passage (12) of the planet carrier (1); The pin shaft (2) has a lubricating oil circuit (23) inside, the lubricating oil circuit (23) being used to transport lubricating oil to the sliding bearing (22), and the oil storage chamber (11) is in communication with the lubricating oil circuit (23).

10. Gear box, characterized in that, It comprises a housing and a planetary transmission mechanism according to any one of claims 1 to 9, wherein the planet carrier (1) is arranged in the housing.

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