Low-power-consumption tooth profile design method for crawler-driving wheel meshing pair

Abstract

The invention discloses a low-power-consumption tooth profile design method for a crawler-driving wheel meshing pair. The method comprises the following steps: constructing a meshing power consumption model of the crawler-driving wheel meshing pair according to a power consumption mechanism of the crawler-driving wheel meshing pair and meshing power consumption factor indexes; based on the meshing power consumption model, taking the lowest power consumption as a target function, and adopting an optimization algorithm to carry out optimization solution on the circular arc center position to obtain an optimal tooth profile or an approximately optimal parameter equation; and designing the tooth form of the crawler-driving wheel meshing pair according to the parameter equation, and correspondingly selecting the material and hardness of the meshing pair. The meshing friction power consumption can be greatly reduced.

Description

Technical Field

[0001] The invention belongs to the field of high-speed tracked vehicles, and in particular relates to a low-power tooth profile design method for a track-driving wheel meshing pair. Background Art

[0002] The track-drive wheel meshing pair transfers the torque output by the powertrain to the track, converting it into traction to propel the vehicle, and transmits the braking force from the ground to brake the vehicle. The mutual meshing of the drive wheel ring gear and the track end connector has a decisive influence on the performance of the track propulsion device.

[0003] At present, the track-driving wheel meshing pair is the link with the lowest transmission efficiency in the propulsion system. There are many factors that affect the transmission efficiency, including lubrication conditions, geometric characteristics and surface characteristics. As we all know, there are design standards for transmission devices such as gears and sprockets, but there is no design standard for the driving wheel ring gear and track end connector of high-speed tracked vehicles. They are still at the stage of empirical design and reference design, and lack theoretical guidance, so it is difficult to obtain efficient transmission.

[0004] There are few literatures on the design of track-driving wheel meshing pairs. Among the available literatures, "High-speed Tracked Vehicle Driving System" introduces the method of determining the pressure angle, which provides a theoretical basis for the design of the gear ring. However, the appropriate pressure angle only ensures that the meshing pair reaches the meshing state without relative sliding, but cannot reduce the power consumption during meshing and disengaging. The document "Tracked Vehicle Driving Mechanics" introduces the method of calculating the sliding friction force during meshing. It assumes that the meshing pair begins to slide when the end connector rotates to one-quarter of the tooth angle of the meshing point. This calculation method ignores the specific tooth shape and can only roughly estimate the meshing power consumption, but cannot guide the tooth shape design.

[0005] At present, under the condition of the same tonnage power, the transmission efficiency of the propulsion system of our military high-speed tracked vehicles is lower than that of similar foreign vehicles, and the meshing area of ​​the driving wheel gear plate is seriously worn under the condition of the same mileage. At the same time, there are also problems such as top teeth, climbing teeth, and unfavorable tooth stripping when the track is engaged, which leads to increased meshing impact, and these problems in turn aggravate the wear of the meshing, reduce the life of the track, and form a vicious circle. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a method for designing the tooth profile of a track-driving wheel meshing pair with high-efficiency transmission from the perspective of structural design, proposes a power consumption calculation model by analyzing the power consumption mechanism of the meshing pair, and proposes a method and principle for designing the tooth profile of a track-driving wheel meshing pair with low power consumption.

[0007] The present invention provides a low-power consumption tooth profile design method for a crawler-driving wheel meshing pair, comprising:

[0008] According to the power consumption mechanism and power consumption factor index of track-driving wheel meshing pair, the meshing power consumption model of track-driving wheel meshing pair is established;

[0009] Based on the meshing power consumption model, taking the minimum power consumption as the objective function, an optimization algorithm is used to find the optimal solution for the arc center position, and the optimal tooth shape or the approximately optimal parameter equation is obtained;

[0010] The tooth shape of the track-driving wheel meshing pair is designed according to the parameter equation, and the material and hardness of the meshing pair are selected accordingly.

[0011] Preferably, the power consumption mechanism of the track-driving wheel meshing pair includes:

[0012] As the driving wheel rotates, the track tension T p Under the action of, the meshing end connector is rotated around the center of the track pin of the previous end connector, and the meshing tooth shape of the end connector approaches the tooth root;

[0013] Since the track pitch is in the track tension T p The gear teeth of the driving wheel that are about to engage with the gear will become longer under the action of the force, while the pitch of the gear teeth that are about to engage with the driving wheel remains unchanged because there is no force. The small pitch increment causes the end connector meshing tooth shape to produce tooth side friction with the tooth root before reaching the meshing point, causing sliding power consumption;

[0014] As the driving wheel continues to rotate, the pressure angle gradually decreases, the positive pressure gradually increases, the pitch difference decreases, and the transmitted power increases; when the end connector is limited by the tooth root arc and no longer slides toward the tooth root, a stable meshing transmission force is formed and no power is consumed. At this time, the pressure angle decreases to the stable meshing value θ s ;

[0015] When meshing, the track tension gradually decreases, the pitch decreases, the meshing pair disengages from contact, and there is no sliding friction power consumption.

[0016] Preferably, the positive pressure is expressed as:

[0017]

[0018] Among them, T pi is the tight side tension of the end connector, which is the sum of the traction force, the track preload and the centrifugal force generated by the rotation of the track, θ is the pressure angle of the contact point of the meshing pair, α is the tooth angle, α=2π / z, z is the number of teeth, and μ is the sliding friction coefficient of the meshing pair.

[0019] Preferably, the formula for the work done from the contact point to stable engagement to overcome the friction during the engagement process is:

[0020]

[0021] Among them, θ0, θ sare the pressure angle at the beginning of contact and the pressure angle after stable meshing, respectively; r is the radius of the arc where the meshing tooth profile is located, θ is the pressure angle of the meshing pair contact point, N(θ) is the normal pressure at contact, μ is the sliding friction coefficient of the meshing pair, α is the tooth angle, α=2π / z, z is the number of teeth, T p The traction force transmitted for meshing.

[0022] Preferably, the process in which the minute pitch increment causes the end connector meshing tooth profile to generate tooth side friction with the tooth root just before reaching the meshing point, thereby causing sliding friction power consumption includes:

[0023] According to the meshing mechanism, the sliding process makes the track pitch gradually approach the driving wheel pitch. The pressure angle θ0 at the beginning of contact is determined by the drawing method, and the traction force T is recorded as p The track pitch increment ΔL under the action is taken as the center of the pin ear of the front end connector, and an arc is drawn with a radius of L+ΔL+r. The pressure angle corresponding to the point where the arc is tangent to the tooth root tooth profile is the initial contact point θ0; similarly, the pressure angle corresponding to the tangent point obtained when drawing an arc with a radius of L+r is the stable meshing point θ s ; Then, as the number of teeth on the driving wheel increases, the meshing friction power consumption fluctuates and increases, wherein the number of teeth on the driving wheel is the minimum power consumption number under the premise of ensuring strength, pitch, etc.

[0024] Preferably, the meshing power consumption factors include but are not limited to track tension, friction coefficient, tooth angle, pressure angle, tooth root arc radius, and pitch;

[0025] Wherein, the inter-tooth angle includes the number of teeth and the pitch;

[0026] The pressure angle includes the pressure angle at the beginning of contact and the pressure angle after stable meshing.

[0027] Preferably, the formula expression of the meshing power consumption model is:

[0028]

[0029] Among them, r is the radius of the arc where the meshing tooth profile is located, μ is the sliding friction coefficient of the meshing pair, T p is the traction force transmitted by meshing, α is the tooth angle, α=2π / z, z is the number of teeth, θ0, θ s They are the pressure angle at the beginning of contact and the pressure angle after stable engagement respectively; the vehicle speed is v, the track pitch is L, the power output of the transmission system is P, the number of times the track-driving wheel engages per second is v / L, and the work required per second is Ev / L.

[0030] Preferably, based on the meshing power consumption model, taking the minimum power consumption as the objective function, the process of using an optimization algorithm to optimize the arc center position includes:

[0031] The track-driving wheel meshing pair includes the root tooth shape of the gear ring and the end connector meshing tooth shape; wherein the root tooth shape takes the minimum sliding power consumption of the meshing pair as the objective function, and the parameters are determined by optimization; the end connector meshing tooth shape is determined by Hertz contact theory;

[0032] Based on the track pulling force, track preload and centrifugal force generated by track rotation, the track preload is adjusted according to the vehicle driving conditions to reduce power consumption during use;

[0033] For a propulsion system with a certain transmission ratio, the meshing power consumption can be reduced by selecting a reasonable number of teeth, pressure angle, arc radius, and center position; wherein the number of teeth is a function of the pitch L and the tooth-to-tooth angle α.

[0034] Preferably, the process of designing the track-driving wheel meshing tooth profile according to the parameter equation includes:

[0035] Based on the meshing power consumption factor, when the tight side tension T pi When the time is certain, the arc radius and the center position with greater influencing factors are selected, and the tooth root profile of the driving wheel is optimized to reduce the meshing power consumption of the driving wheel;

[0036] The tooth top, tooth profile, and tooth bottom profile that have no effect on power consumption continue to use the traditional structure; wherein the tooth profile and tooth shape only need to be excessively smooth with the tooth root profile, including but not limited to involute tooth profile, circular arc, and straight line;

[0037] Taking the driving wheel meshing power consumption model as the objective function, the particle swarm algorithm is used to perform local optimization and optimal solution to determine the tooth profile parameters through random combination of the center coordinates and the radius, and then the track-driving wheel meshing pair tooth profile is designed.

[0038] Preferably, the process of taking the driving wheel meshing power consumption model as the objective function and using the particle swarm algorithm to perform local optimization and optimal solution to determine the tooth profile parameters by random combination of the center coordinates and the radius includes:

[0039] Assuming the coordinates of the center of the circle are (a, b) and the radius is r, the center position is optimized according to the driving gear meshing power consumption model; specifically, the following are included:

[0040] Determine the pitch radius and number of teeth of the driving wheel according to the transmission ratio of the transmission system, and then determine the minimum allowable radius r of the end connector arc according to the relationship between the maximum tension of the track and the material strength. m , initially set the minimum allowable radius r of the end connector arc m As the radius of the tooth profile arc, and then taking the lowest power consumption as the objective function, the optimization method is used to find the optimal position of the circle center to obtain the optimal or approximately optimal tooth profile.

[0041] Compared with the prior art, the present invention has the following advantages and technical effects:

[0042] The present invention establishes a meshing power consumption model of the track-driving wheel meshing pair according to the power consumption mechanism of the track-driving wheel meshing pair and the meshing power consumption factor index, and then takes the minimum power consumption as the objective function, adopts an optimization algorithm to optimize the arc center position, and obtains the optimal tooth shape or a nearly optimal parameter equation; designs the tooth shape of the track-driving wheel meshing pair according to the parameter equation, and selects the material and hardness of the meshing pair accordingly. The present invention can greatly reduce the meshing friction power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0044] Figure 1 A schematic diagram of the tooth profile of the driving wheel ring gear according to an embodiment of the present invention;

[0045] Figure 2 is a schematic diagram of an end connector according to an embodiment of the present invention;

[0046] Figure 3 It is a force analysis diagram of the meshing embodiment of the present invention;

[0047] Figure 4 It is an engineering drawing of a gear ring according to an embodiment of the present invention;

[0048] Figure 5 is a flowchart of the steps of an embodiment of the present invention;

[0049] Among them, 1. driving wheel; 2. tooth top arc; 3. tooth profile arc; 4. gear teeth; 5. tooth root; 7. tooth bottom arc; 8. gear ring fixing hole; 9. end connector; 10. minimum allowable radius of end connector; 11. track pin; 12. center connection line of adjacent track pins; 13. end connector meshing tooth shape; 14. driving wheel rotation direction. DETAILED DESCRIPTION

[0050] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0051] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0052] like Figure 1-5 As shown, this embodiment provides a low-power tooth profile design method for a track-driving wheel meshing pair, including:

[0053] According to the power consumption mechanism and power consumption factor index of track-driving wheel meshing pair, the meshing power consumption model of track-driving wheel meshing pair is established;

[0054] Based on the meshing power consumption model, taking the minimum power consumption as the objective function, an optimization algorithm is used to find the optimal solution for the arc center position, and the optimal tooth shape or the approximately optimal parameter equation is obtained;

[0055] The tooth shape of the track-driving wheel meshing pair is designed according to the parameter equation, and the material and hardness of the meshing pair are selected accordingly.

[0056] The track-driving wheel meshing pair includes a driving wheel 1, a tooth top arc 2, a tooth profile arc 3, a gear tooth 4, a tooth root 5, a tooth bottom arc 7, a gear ring fixing hole 8, an end connector 9, a minimum allowable radius of the end connector 10, a track pin 11, a connecting line of the centers of adjacent track pins 12, an end connector meshing tooth profile 13, and a driving wheel rotation direction 14. Among them, the tooth root 5 tooth profile takes the minimum sliding power consumption of the meshing pair as the objective function, and the parameters are determined by optimization; the tooth profile is an involute tooth profile or an arc tooth profile. The parameters of the end connector meshing tooth profile 13 are determined by Hertz contact theory;

[0057] The power consumption mechanism of the track-driving wheel meshing pair includes:

[0058] As the driving wheel 1 rotates, the track tension T p Under the action of the track tension T, the meshing end connector 9 rotates around the center of the track pin 11 of the previous end connector, and the meshing tooth shape 13 of the end connector moves closer to the tooth root 5. p The gear teeth 4 of the driving wheel 1 that are about to engage do not change their pitch because they are not subjected to force. The tiny pitch increment causes the end connector meshing tooth shape 13 to produce tooth side friction with the tooth root 5 before reaching the meshing point, causing sliding power consumption.

[0059] As the driving wheel 1 continues to rotate, the pressure angle gradually decreases, the positive pressure N gradually increases, the pitch difference decreases, and the transmitted power increases; when the end connector 9 is limited by the tooth root arc and no longer slides toward the tooth root, a stable meshing transmission force is formed and no power is consumed. At this time, the pressure angle (i.e. the angle between the normal line of the meshing point and the connecting line of the centers of the adjacent chain pins transmitting the force) is reduced by the stable meshing value θ s .

[0060] When meshing, the track tension gradually decreases, the pitch decreases, the meshing pair disengages from contact, and there is no sliding friction power consumption.

[0061] Furthermore, the meshing power consumption factor is related to factors such as track tension, friction coefficient, tooth angle, pressure angle, tooth root arc radius, pitch, etc. Among them, the tooth angle includes the number of teeth and pitch; the pressure angle includes the pressure angle at the beginning of contact and the pressure angle after stable meshing.

[0062] Further, after the stable engagement, the stress of the rear connector 9 is as follows: Figure 3 As shown, N i is positive pressure, T ci is the tension of the loose side of the end connector 9, T pi is the tension of the end connector 9, that is, the sum of the traction force, the pre-tightening force of the track and the centrifugal force generated by the rotation of the track, θ is the pressure angle of the contact point of the meshing pair, μ is the sliding friction coefficient of the meshing pair, α is the tooth angle, α=2π / z, z is the number of teeth, then when the meshing is stable, the balance formula of each component force on the x and y axes is:

[0063] N i +T ci cos(α+θ)-T pi cosθ=0 (1)

[0064] T pi sinθ+μN i -T ci sin(α+θ)=0 (2)

[0065] Combining the two equations, we can eliminate T ci Term, simplifying to get the expression of normal pressure:

[0066]

[0067] Furthermore, r is the radius of the circular arc where the meshing tooth profile is located, θ is the pressure angle of the meshing pair contact point, N(θ) is the normal pressure during contact, μ is the sliding friction coefficient of the meshing pair, α is the tooth angle, α=2π / z, z is the number of teeth, and the relative sliding distance of the meshing pair is dθ s =rdθ; let θ0, θ s They are the pressure angle at the beginning of contact and the pressure angle after stable meshing. According to the definition of work done, the work done by friction is:

[0068] dE=μN(θ)rdθ(4)

[0069] Remember T p The traction force transmitted by meshing is expressed in the form of an integral to overcome the friction work from the contact point to the stable meshing during the meshing process:

[0070]

[0071] Let the vehicle speed be v, the track pitch be L, and the power output of the transmission system be P. Then the number of times the track-driving wheel engages per second is v / L, that is, the work required per second is Ev / L. The calculation model for the track engagement power consumption is:

[0072]

[0073] Furthermore, since the track tension includes traction, track preload and centrifugal force generated by the rotation of the track, the track preload can be adjusted according to the vehicle driving conditions during use to reduce power consumption. On the other hand, power consumption can be reduced by optimizing the tooth shape during the design phase. Specifically, for a propulsion system with a certain transmission ratio (i.e., the pitch radius of the driving wheel is fixed), the meshing power consumption can be reduced by selecting a reasonable number of teeth, pressure angle, arc radius, and center position. Among them, the number of teeth is a function of the pitch L and the tooth angle α.

[0074] Furthermore, the process of determining the pressure angle θ0 at the beginning of contact includes:

[0075] According to the meshing mechanism, the sliding process is the process in which the track pitch gradually approaches the driving wheel pitch. The pressure angle θ0 at the beginning of contact can be determined by the drawing method. The traction force T p The track pitch increment ΔL under the action is taken as the center of the circle, and the arc is drawn with the center of the pin ear 11 of the front end connector as the center and the radius L+ΔL+r. The pressure angle corresponding to the point where the arc is tangent to the tooth root tooth profile is the initial contact point θ0; similarly, the pressure angle corresponding to the tangent point obtained when drawing an arc with the radius L+r is the stable meshing point θ s .

[0076] As the number of teeth on the driving wheel increases, the meshing friction power consumption shows a fluctuating upward trend; the number of teeth mentioned above is the minimum power consumption number under the premise of ensuring strength, pitch, etc.;

[0077] Furthermore, the track-driving wheel meshing pair tooth profile design process includes:

[0078] According to the factors affecting the power consumption of the driving wheel meshing, when the tight side tension T p In order to reduce the meshing power consumption of the driving wheel, the arc radius and the center position with greater influencing factors can be selected to optimize the design of the root tooth shape of the driving wheel. The tooth shapes such as the top, profile, and bottom of the tooth that have no effect on power consumption continue to use the traditional structure. The tooth profile can be an involute tooth shape, an arc, or a straight line, and it only requires to be smooth with the root tooth shape.

[0079] Taking the driving wheel meshing power consumption model as the objective function, the particle swarm algorithm is used to perform local optimization and solve the tooth profile parameters through the random combination of the center coordinates and the radius; the specific process includes:

[0080] Assuming the coordinates of the circle center are (a, b) and the radius is r, the center position is optimized according to the driving gear meshing power consumption model. The specific process includes:

[0081] Determine the pitch radius and number of teeth of the driving wheel according to the transmission ratio (maximum vehicle speed) of the transmission system, and then determine the minimum allowable radius r of the end connector according to the relationship between the maximum tension of the track and the material strength. m, initially the radius is taken as the radius of the tooth profile arc, and finally the minimum power consumption is taken as the objective function, and the optimization method is used to find the optimal position of the circle center to obtain the optimal or approximately optimal tooth profile.

[0082] The arc radius of the meshing tooth profile 13 is slightly smaller than the arc radius of the tooth root tooth profile; preferably, the clearance fit tolerance of the two arcs is H8 / c7, and the maximum surface roughness is 1.6;

[0083] To further optimize the scheme, the design principles of the track-drive wheel meshing pair include:

[0084] The greater the track stiffness, the smaller the deformation of the track under the same load, which helps to reduce the sliding distance. When designing the track, it is appropriate to have a sub-pitch and avoid super-pitch. That is, it is beneficial for the track pitch to be smaller than the driving wheel gear ring pitch, and it should be avoided that the track pitch is larger than the driving wheel gear ring pitch. Sub-pitch helps to shorten the sliding distance when meshing. Modern tracks use a pin-ear hanging rubber structure to reduce the longitudinal tensile stiffness of the track and apply a large preload. After the track is installed, both factors will increase the track pitch. Therefore, this factor should be considered during design and the track should be designed as a sub-pitch. However, a large pitch difference can easily cause meshing impact.

[0085] (2) As the number of teeth on the driving wheel increases, the meshing friction power consumption shows a fluctuating upward trend. Under the premise of ensuring smooth transmission, the number of teeth on the driving wheel should be reduced, preferably 11 or 12.

[0086] (3) The tooth profile arc 3 can be an asymptote, an arc, or a straight line, and is only required to be smoothly transitioned with the tooth root arc 5.

[0087] Furthermore, the material of the meshing pair is preferably a wear-resistant material with a small friction coefficient;

[0088] like Figure 3 As shown, this embodiment provides a low-power tooth shape, which includes a tooth top arc 2, a tooth profile arc 3, a tooth root arc, and a tooth bottom arc 7; in practical applications, the tooth profile arc 3 can be an asymptote, an arc, or a straight line. Based on a certain type of multi-segment arc tooth shape currently in service, this embodiment improves and optimizes the driving wheel tooth root arc 5.

[0089] Low-power gear profile optimization is a single-objective optimization problem. The objective function can be expressed as

[0090] minP nh2

[0091] θ s .tr≥r m , a, b∈[a m , b m ]

[0092] The optimization algorithm is used to find the optimal solution, where the population size N is 100 and the maximum number of iterations is 5000. The optimization results are shown in Table 1.

[0093] Table 1

[0094]

[0095] It can be seen that with the optimization of the arc tooth profile of the working section, the meshing power consumption is significantly reduced.

[0096] The arc equations after optimization are as follows. The drawing and engineering drawing are as follows: Figure 4 .

[0097] Tip arc:

[0098] x 2 +(y-305.075) 2 =11 2 ,θ1=110.08°

[0099] Tooth profile arc:

[0100] (x+40.98) 2 +(y-276.42) 2 =65 2 ,θ2=34.05°

[0101] Tooth root arc:

[0102] (x+39.01) 2 +(y-277.70) 2 =22 2 ,θ3=73.39°

[0103] Tooth bottom arc:

[0104] (x+29.00) 2 +(y-242.08) 2 =18 2 ,θ4=44.64°

[0105] Furthermore, in order to reduce the friction coefficient, the materials and heat treatment hardness of the gear ring and the end connector are optimized.

[0106] The preferred material for the gear ring is 20Cr2Ni4A, profile milling, heat treatment and tempering, tooth profile and tooth root surface carburizing, hardness HRC55-59.

[0107] The end connector is preferably made of 35Crmo steel, precision cast, and the working surface hardness after heat treatment is HRC30-39.

[0108] It should be noted that the preferred number of teeth is 11. In this embodiment, for the convenience of experiment, there is no need to manufacture the entire crawler track, and the number of teeth is 12.

[0109] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A low-power tooth profile design method for a track-driving wheel meshing pair, characterized in that: include: According to the power consumption mechanism and power consumption factor index of track-driving wheel meshing pair, the meshing power consumption model of track-driving wheel meshing pair is established; Based on the meshing power consumption model, taking the minimum power consumption as the objective function, an optimization algorithm is used to find the optimal solution for the arc center position, and the optimal tooth shape or the approximately optimal parameter equation is obtained; The tooth shape of the track-driving wheel meshing pair is designed according to the parameter equation, and the material and hardness of the meshing pair are selected accordingly.

2. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 1, characterized in that: The power consumption mechanism of the track-driving wheel meshing pair includes: As the driving wheel rotates, the track tension T p Under the action of, the meshing end connector is rotated around the center of the track pin of the previous end connector, and the meshing tooth shape of the end connector approaches the tooth root; Since the track pitch is in the track tension T p The gear teeth of the driving wheel that are about to engage with the gear will become longer under the action of the force, while the pitch of the gear teeth that are about to engage with the driving wheel remains unchanged because there is no force. The small pitch increment causes the end connector meshing tooth shape to produce tooth side friction with the tooth root before reaching the meshing point, causing sliding power consumption; As the driving wheel continues to rotate, the pressure angle gradually decreases, the positive pressure gradually increases, the pitch difference decreases, and the transmitted power increases; when the end connector is limited by the tooth root arc and no longer slides toward the tooth root, a stable meshing transmission force is formed and no power is consumed. At this time, the pressure angle decreases to the stable meshing value θ s ; When meshing, the track tension gradually decreases, the pitch decreases, the meshing pair disengages from contact, and there is no sliding friction power consumption.

3. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 2, characterized in that: The formula expression of the positive pressure is: Among them, T pi is the tight side tension of the end connector, which is the sum of the traction force, the track preload and the centrifugal force generated by the rotation of the track, θ is the pressure angle of the contact point of the meshing pair, α is the tooth angle, α=2π / z, z is the number of teeth, and μ is the sliding friction coefficient of the meshing pair.

4. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 2, characterized in that: The formula for overcoming friction during the meshing process from the contact point to stable meshing is: Among them, θ0, θ s are the pressure angle at the beginning of contact and the pressure angle after stable meshing, respectively; r is the radius of the arc where the meshing tooth profile is located, θ is the pressure angle of the meshing pair contact point, N(θ) is the normal pressure at contact, μ is the sliding friction coefficient of the meshing pair, α is the tooth angle, α=2π / z, z is the number of teeth, T p The traction force transmitted for meshing.

5. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 2, characterized in that: The process in which the minute pitch increment causes the end connector meshing tooth profile to generate tooth side friction with the tooth root just before reaching the meshing point, causing sliding power consumption includes: According to the meshing mechanism, the sliding process makes the track pitch gradually approach the driving wheel pitch. The pressure angle θ0 at the beginning of contact is determined by the drawing method, and the traction force T is recorded as p The track pitch increment ΔL under the action is taken as the center of the pin ear of the front end connector, and an arc is drawn with a radius of L+ΔL+r. The pressure angle corresponding to the point where the arc is tangent to the tooth root tooth profile is the initial contact point θ0; similarly, the pressure angle corresponding to the tangent point obtained when drawing an arc with a radius of L+r is the stable meshing point θ s ; Then, as the number of teeth on the driving wheel increases, the meshing friction power consumption fluctuates and increases, wherein the number of teeth on the driving wheel is the minimum power consumption number under the premise of ensuring strength, pitch, etc.

6. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 1, characterized in that: The meshing power consumption factors include but are not limited to track tension, friction coefficient, tooth angle, pressure angle, tooth root arc radius, and pitch; Wherein, the inter-tooth angle includes the number of teeth and the pitch; The pressure angle includes the pressure angle at the beginning of contact and the pressure angle after stable meshing.

7. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 1, characterized in that: The formula expression of the meshing power consumption model is: Among them, r is the radius of the arc where the meshing tooth profile is located, μ is the sliding friction coefficient of the meshing pair, T p is the traction force transmitted by meshing, α is the tooth angle, α=2π / z, z is the number of teeth, θ0, θ s They are the pressure angle at the beginning of contact and the pressure angle after stable engagement respectively; the vehicle speed is v, the track pitch is L, the power output of the transmission system is P, the number of times the track-driving wheel engages per second is v / L, and the work required per second is Ev / L.

8. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 1, characterized in that: Based on the meshing power consumption model, taking the minimum power consumption as the objective function, the process of using the optimization algorithm to find the optimal solution for the arc center position includes: The track-driving wheel meshing pair includes the root tooth shape of the gear ring and the end connector meshing tooth shape; wherein the root tooth shape takes the minimum sliding power consumption of the meshing pair as the objective function, and the parameters are determined by optimization; the end connector meshing tooth shape is determined by Hertz contact theory; Based on the track pulling force, track preload and centrifugal force generated by track rotation, the track preload is adjusted according to the vehicle driving conditions to reduce power consumption during use; For a propulsion system with a certain transmission ratio, the meshing power consumption can be reduced by selecting a reasonable number of teeth, pressure angle, arc radius, and center position; wherein the number of teeth is a function of the pitch L and the tooth-to-tooth angle α.

9. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 1, characterized in that: The process of designing the track-driving wheel meshing tooth profile according to the parametric equation includes: Based on the meshing power consumption factor, when the tight side tension T pi When the time is certain, the arc radius and the center position with greater influencing factors are selected, and the tooth root profile of the driving wheel is optimized to reduce the meshing power consumption of the driving wheel; The tooth top, tooth profile, and tooth bottom profile that have no effect on power consumption continue to use the traditional structure; wherein the tooth profile and tooth shape only need to be excessively smooth with the tooth root profile, including but not limited to involute tooth profile, circular arc, and straight line; Taking the driving wheel meshing power consumption model as the objective function, the particle swarm algorithm is used to perform local optimization and optimal solution to determine the tooth profile parameters through random combination of the center coordinates and the radius, and then the track-driving wheel meshing pair tooth profile is designed.

10. The low power consumption tooth profile design method for the track-driving wheel meshing pair according to claim 9, characterized in that: Taking the driving wheel meshing power consumption model as the objective function, the process of determining the tooth profile parameters by using the particle swarm algorithm for local optimization and optimal solution through the random combination of the center coordinates and the radius includes: Assuming the coordinates of the center of the circle are (a, b) and the radius is r, the center position is optimized according to the driving gear meshing power consumption model; specifically, the following are included: Determine the pitch radius and number of teeth of the driving wheel according to the transmission ratio of the transmission system, and then determine the minimum allowable radius r of the end connector arc according to the relationship between the maximum tension of the track and the material strength. m , initially set the minimum allowable radius r of the end connector arc m As the radius of the tooth profile arc, and then taking the lowest power consumption as the objective function, the optimization method is used to find the optimal position of the circle center to obtain the optimal or approximately optimal tooth profile.

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