A method for modifying the tooth profile of friction plate in liquid-viscous speed control clutch

Abstract

The present invention discloses a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch, comprising the following steps: step 1, radial modification of external teeth: when radial deformation occurs to the external teeth of the friction plate, tooth top modification is adopted; three coordinate points after modification are obtained by the intersection of the involute equation and the tooth top circle equation and the deformation amount, the three points are connected by a hyperbola to obtain a modification curve, and radial repair of the external teeth is performed according to the modification curve; step 2, radial modification of internal teeth: when radial deformation occurs to the internal teeth of the friction plate, a radial displacement compensation mechanism is provided to compensate for the radial deformation, and radial modification of the internal teeth of the friction plate is performed; step 3, axial modification of internal teeth: when axial deformation occurs to the internal teeth of the friction plate, a displacement correction method is adopted to increase the tooth thickness for repair. The present invention takes into account the modification of deformation of the friction plate under different working conditions, improves the tooth contact stress and extrusion stress, and solves the problem that the friction plate teeth can still transmit normally after deformation under different working conditions.

Description

Technical Field

[0001] The invention relates to the technical field of liquid-viscous transmission, in particular to a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch. Background Art

[0002] The series of liquid-viscous speed-regulating clutch products are a new type of power transmission energy-saving device manufactured using the new oil film shearing technology. It has good speed-regulating performance and can be widely used in the speed regulation of high-power water pumps, fans and various working machines in the petroleum, chemical, metallurgy, electric power, coal and other industries. It can effectively solve the energy waste problem generated by various working machines such as water pumps and fans, and has a significant energy-saving effect.

[0003] When the clutch is working, the heat generated by friction causes the friction plate and the mating plate to expand due to heat, and the heating is uneven, resulting in internal constraints. At the same time, there are external deformation constraints, so thermal deformation cannot proceed freely, and thermal stress is generated in the clutch plate. During operation, the thermal stress value at each point in the plate changes with the change of temperature and constraints. Once its value increases to exceed the yield point of the material, the material will have irreversible plastic strain, and the friction plate or steel plate will have permanent deformation.

[0004] Since the friction plate transmission inevitably has manufacturing errors, installation errors and stress deformation of the friction plate tooth transmission, and the transmission inevitably produces vibration and noise, especially in some high-speed and heavy-load transmission devices. Tooth profile repair is an effective technology to reduce the vibration and noise of the friction plate tooth transmission device and improve the transmission efficiency. It has been more and more widely used in recent years.

[0005] Patent 201110145011.5 discloses a shaping method and manufacturing method for an involute spur planetary transmission gear, which obtains the torsional deformation of the sun gear shaft tooth width section, the bending deformation of the planetary gear shaft tooth width section, and the elastic deformation of the planetary gear teeth according to a predetermined load value; the involute spur planetary transmission gear is shaped in a virtual environment according to the initial value of the shaping amount; the shaped involute spur planetary transmission gear is evaluated and verified, and the final shaping amount is determined according to the evaluation and verification results. The shaping method of the present invention eliminates the unbalanced load phenomenon of the planetary gear meshing, thereby improving the transmission stability of the gear, increasing the gear's load-bearing capacity, and extending the gear's service life.

[0006] Chinese patent application number 201410087456.6 discloses a method for modifying the tooth profile of an involute gear, which modifies the tooth tops of both the driving wheel and the driven wheel that mesh with each other, and improves the contact deformation and contact stress when the gear teeth mesh in and out. However, the patent only considers the modification during the gear meshing process, and does not consider the radial deformation and axial deformation of the friction plate teeth.

[0007] The present invention takes into account the deformation and shaping of the friction plate under different working conditions, improves the tooth contact stress and extrusion stress, and solves the problem that the friction plate teeth can still transmit normally after being deformed under different working conditions. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a method for modifying the tooth profile of a friction plate in a liquid-viscous speed control clutch in response to the deficiencies of the above-mentioned prior art. The method takes into account the modification of the deformation of the friction plate under different working conditions, improves the tooth contact stress and extrusion stress, and solves the problem that the friction plate teeth can still transmit normally after being deformed under different working conditions.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch, which specifically comprises the following steps:

[0010] Step 1, radial modification of external teeth: When radial deformation occurs to the external teeth of the friction plate, tooth top modification is adopted; the three coordinate points after modification are obtained by the intersection of the involute equation and the tooth top circle equation and the deformation amount, and the three points are connected by a hyperbola to obtain a modification curve, and radial repair of the external teeth is performed according to the modification curve;

[0011] Step 2, radial modification of the inner teeth: when radial deformation occurs in the inner teeth of the friction plate, the radial deformation is compensated; the deformation of the inner teeth is measured by a magnetostrictive displacement sensor embedded in the teeth, and the displacement is fed back to the controller through an encoder; the controller drives the displacement table to slide up and down, and the radial elastic deformation of the friction plate is compensated by the sliding displacement on the displacement table;

[0012] Step 3, axial shaping of the inner teeth: When axial deformation occurs on the inner teeth of the friction plate, the displacement correction method is used to increase the tooth thickness for repair.

[0013] As a further preferred embodiment of the present invention, in step 1, when radial deformation occurs to the outer teeth of the friction plate, the deformation amount Δl of the radial deformation of the outer teeth of the friction plate is first calculated.

[0014] Δl is obtained by curve fitting:

[0015] Δl=4.355-1.198×10 -7 q-0.621μ-0.016b

[0016] Among them, q is the heat flux density of the dual plate, b is the outer diameter of the friction plate, and μ is the viscosity of the lubricating oil.

[0017] As a further preferred embodiment of the present invention, the coordinates of the intersection point A of the involute equation and the tooth top circle equation are (x A ,y A ); the three coordinate points after modification are B(x B ,y B)、C(x C ,y C )、D(x D ,y D ).

[0018] Point B is the vertex coordinate of the modified curve, and y B =y A -Δl, that is, the coordinates of point B are B(x A ,y A -Δl).

[0019] The coordinates of point C are C(x C ,y C ), there is x C =r b Sinu C +r b u C cosu C ,y C =r b cosu C -r b u C Sinu C , where r b is the radius of the pitch circle; and the ordinate y of point C C =y B -Δl.

[0020] The coordinates of point D are

[0021] As a further preferred embodiment of the present invention, the curvature radius of the modified curve is greater than the curvature radius of the original curve.

[0022] As a further preferred embodiment of the present invention, in step 2, when radial deformation occurs to the inner teeth of the friction plate, a radial displacement compensation mechanism is provided to compensate for the radial deformation and radially modify the inner teeth of the friction plate.

[0023] The displacement compensation mechanism includes a magnetostrictive displacement sensor, a piezoelectric displacement platform, a guide rail, a slider, a piezoelectric ceramic displacement block, a push rod, an encoder, and a controller.

[0024] The magnetostrictive displacement sensor is arranged at a radial position of the friction plate.

[0025] The L-shaped base of the piezoelectric displacement stage is fixed on the box; the guide rail is vertically fixed on one plane of the L-shaped base and parallel to the other plane; a slider is sleeved on the guide rail, a piezoelectric ceramic displacement block is fixed on one end face of the slider, and a push rod is fixed on the other end face; one end of the push rod is connected to the slider, and the other end of the push rod is embedded in the inner diameter of the friction plate.

[0026] An encoder and a controller are also arranged on the piezoelectric displacement stage.

[0027] As a further preferred embodiment of the present invention, the waveguide tube of the detection element on the magnetostrictive displacement sensor is arranged inside the tooth tops of the inner teeth of the friction plate, and the waveguide tube cannot protrude outside the tooth tops of the inner teeth of the friction plate.

[0028] As a further preferred embodiment of the present invention, in step 3, when the inner teeth of the friction plate undergo axial deformation, the deformation amount Δl′ of the inner teeth of the friction plate is first calculated.

[0029] Δl′ is obtained by curve fitting:

[0030] Δl′=3.920-9.223×10 -8 q-0.853μ-0.16b′+0.002a′

[0031] Among them, q is the heat flux density of the dual plate, μ is the viscosity of the lubricating oil, a′ is the inner diameter of the friction plate, and b′ is the outer diameter of the friction plate.

[0032] As a further preferred embodiment of the present invention, according to the dish-shaped deformation law, the deformation of the inner and outer teeth of the friction plate is distributed in a positive and negative manner along the tooth thickness direction. Taking the modification of the inner teeth of the friction plate as an example:

[0033] Original tooth thickness m is the module of the gear.

[0034] When the tool position is moved outward by a distance of Δl′ from the standard position, the tooth width on the tool pitch line increases by 2KJ compared with the tooth width on the indexing line. 2KJ=Δl′, and the tooth thickness increases accordingly. The tooth thickness of the gear after the displacement is:

[0035] The tooth thickness increases, the meshing angle increases, and the root stress decreases, thereby compensating for the radial deformation of the internal teeth.

[0036] The present invention has the following beneficial effects:

[0037] 1. When the outer teeth are radially modified in the present invention, the curvature radius of the modified curve is larger than the curvature radius of the original curve, and the modified curve is smoother than the original curve. When resisting radial pressure, the impact of the teeth is smaller and the operation is smoother.

[0038] 2. The present invention is for radial repair of internal teeth, and the device used is simple, compact in structure, and can accurately compensate for radial deformation.

[0039] 3. The tooth profile after the axial internal tooth repair of the present invention can compensate for the elastic deformation of the friction plate caused by the axial pressure and contact pressure between the friction pairs, thereby ensuring the normal transmission of the friction plate.

[0040] 4. The present invention takes into account the deformation and modification of the friction plate under different working conditions, and improves the tooth contact stress and extrusion stress, thereby solving the problem that the friction plate teeth can still transmit normally after being deformed under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention discloses a radial deformation diagram of the outer teeth of a friction pair in a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch.

[0042] Figure 2 The outer tooth radial modification curve diagram and the original curve diagram of the modification method of the friction plate tooth profile in the liquid viscous speed regulating clutch of the present invention are shown in FIG.

[0043] Figure 3 The present invention is a schematic diagram of the structure of a clutch portion of a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch.

[0044] Figure 4 The invention discloses a schematic diagram of the installation of a sensor and a push rod in a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch.

[0045] Figure 5 It is a piezoelectric displacement table diagram of a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch according to the present invention.

[0046] Figure 6 The invention discloses an axial inner tooth modification diagram of a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch.

[0047] Figure 7 The invention discloses a tooth thickness processing diagram of axial inner tooth repairing of a method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch.

[0048] The components include: 1. radial displacement compensation mechanism; 2. magnetostrictive displacement sensor; 3. piezoelectric displacement table; 4. guide rail; 5. slider; 6. piezoelectric ceramic displacement block; 7. ejector rod; 8. encoder; 9. controller; and 10. housing. DETAILED DESCRIPTION

[0049] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0050] A method for modifying the tooth profile of a friction plate in a liquid-viscous speed regulating clutch comprises the following steps:

[0051] Step 1, radial modification of external teeth: When radial deformation occurs to the external teeth of the friction plate, tooth top modification is adopted; the three coordinate points after modification are obtained by the intersection of the involute equation and the tooth top circle equation and the deformation amount, and the three points are connected by a hyperbola to obtain a modification curve, and radial repair of the external teeth is performed according to the modification curve; the curvature radius of the modification curve is greater than the curvature radius of the original curve;

[0052] Step 2, radial shaping of the inner teeth: when radial deformation occurs to the inner teeth of the friction plate, a radial displacement compensation mechanism is provided to compensate for the radial deformation, and radial shaping of the inner teeth of the friction plate is performed;

[0053] The deformation of the inner teeth is measured by the magnetostrictive displacement sensor embedded in the teeth, and the displacement is fed back to the controller through the encoder; the controller drives the displacement table to slide up and down, and the radial elastic deformation of the friction plate is compensated by the sliding displacement on the displacement table;

[0054] Step 3, axial shaping of the inner teeth: When axial deformation occurs on the inner teeth of the friction plate, the displacement correction method is used to increase the tooth thickness for repair.

[0055] In step 1, when the outer teeth of the friction plate are radially deformed, the deformation amount Δl of the outer teeth of the friction plate is first calculated;

[0056] Δl is obtained by curve fitting:

[0057] Δl=4.355-1.198×10 -7 q-0.621μ-0.016b

[0058] Among them, q is the heat flux density of the dual plate, b is the outer diameter of the dual plate, and μ is the viscosity of the lubricating oil.

[0059] The coordinates of the intersection point A of the involute equation and the tooth top circle equation are (x A ,y A ); the three coordinate points after modification are B(x B ,y B )、C(x C ,y C )、D(x D ,y D ).

[0060] Point B is the vertex coordinate of the modified curve, and y B =y A -Δl, that is, the coordinates of point B are B(x A ,y A -Δl);

[0061] The coordinates of point C are C(x C ,y C ), there is x C =r b SinuC +r b u C cosu C ,y C =r b cosu C -r b u C Sinu C , where r b is the radius of the pitch circle; and the ordinate y of point C C =y B -Δl;

[0062] The coordinates of point D are

[0063] In step 2, if Figure 3 , 4 As shown in , 5 , the radial displacement compensation mechanism 1 includes a magnetostrictive displacement sensor 2, a piezoelectric displacement stage 3, a guide rail 4, a slider 5, a piezoelectric ceramic displacement block 6, a push rod 7, an encoder 8, and a controller 9.

[0064] by Figure 5 For example, the magnetostrictive displacement sensor 2 is arranged in the radial position of the friction plate; the L-shaped base 11 of the piezoelectric displacement stage 3 is fixed on the box 10; the guide rail 4 is vertically fixed on one plane of the L-shaped base 11 and parallel to the other plane of the L-shaped base 11; a slider 5 is sleeved on the guide rail 4, and the piezoelectric ceramic displacement block 6 is fixed on the right end face of the slider 5, and the push rod 7 is fixed on the left end face; one end of the push rod 7 is connected to the slider 5, and the other end of the push rod 7 is embedded in the inner diameter of the friction plate.

[0065] An encoder 8 and a controller 9 are also provided on the piezoelectric displacement stage 3 .

[0066] The waveguide tube of the detection element on the magnetostrictive displacement sensor is arranged inside the tooth top of the inner tooth of the friction plate, and the waveguide tube cannot protrude outside the tooth top of the inner tooth of the friction plate.

[0067] In step 3, when the inner teeth of the friction plate are axially deformed, the deformation amount Δl′ of the inner teeth of the friction plate is first calculated;

[0068] Δl′ is obtained by curve fitting:

[0069] Δl′=3.920-9.223×10 -8 q-0.853μ-0.16b′+0.002a′

[0070] Among them, q is the heat flux density of the dual plate, μ is the viscosity of the lubricating oil, a′ is the inner diameter of the friction plate, and b′ is the outer diameter of the friction plate.

[0071] According to the dish deformation law, the deformation of the inner and outer teeth of the friction plate is distributed in a positive and negative manner along the tooth thickness direction. Take the modification of the inner teeth of the friction plate as an example:

[0072] Original tooth thickness m is the module of the gear;

[0073] When the tool position is moved outward by a distance of Δl′ from the standard position, the tooth width on the tool pitch line increases by 2KJ compared with the tooth width on the indexing line. 2KJ=Δl′, and the tooth thickness increases accordingly. The tooth thickness of the gear after the displacement is: The tooth thickness increases, the meshing angle increases, and the root stress decreases, thereby compensating for the radial deformation of the internal teeth.

[0074] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0075] Considering that the friction plate teeth are connected by splines, there are two ways of spline matching: one is side matching, in which the matching splines only contact each other on the tooth side, and there is a gap between the spline tooth top and the tooth root; the other is radial matching spline, that is, the matching splines only match in the radial direction, and the tooth side only plays the role of transferring load. There are many ways of deformation in the meshing of friction plate teeth, which need to be analyzed according to different working conditions.

[0076] 1. Radial deformation of the outer teeth of the friction plate

[0077] When the outer teeth of the friction plate undergo radial deformation, the actual deformation of the outer teeth of the friction plate is first calculated. Given that the heat flux density q of the dual plate is 5.7383×10 5 (w / mm 2 ), the outer diameter b of the friction plate in the friction pair is 260 mm, the inner diameter a of the friction plate is 180 mm, the outer diameter b' of the dual plate is 250 mm, the inner diameter a' of the dual plate is 170 mm, and the viscosity of the lubricating oil is μ, which is 0.03461 Pa·s. By changing the heat flux density, the inner and outer diameters of the friction plate, and the viscosity of the lubricating oil, and by curve fitting, the relationship between the deformation amount Δl of the radial deformation of the external gear and the above parameters is obtained as follows:

[0078] Δl=4.355-1.198×10 -7 q-0.621μ-0.016b

[0079] Taking the friction plate thickness of 3mm as an example, the deformation of the friction plate teeth is 0.027779mm according to the above formula and its simulation results. Figure 1 As shown in the figure, the value increases gradually from the direction of the arrow. In the friction plate, the deformation increases gradually from the inner teeth to the outer teeth.

[0080] The deformation of the tooth top is removed, and the contour is modified as follows Figure 2 .

[0081] Gear parameters: number of teeth z = 42, module m = 4mm, pressure angle θ = 20°, tooth top height coefficient h a *=1, top gap coefficient c*=0.25, and the deformation Δl is approximately 0.028mm. The B, C, and D coordinates are located on the modified contour, such as Figure 2 As shown; the vertical distance between AB is the shaping amount, and now we need to determine the shaping outline.

[0082] The equation of the involute tooth profile is:

[0083] r k =r b / cos a k

[0084] θ k =inva k =tana k -a k

[0085] When converted to a right angle to represent the involute:

[0086] x k =r b Sinu k +r b u k cosu k

[0087] y k =r b cosu k -r b u k Sinu k

[0088] where u k =θ k +a k

[0089] Determine the coordinates of point A: The coordinates of point A are the intersection of the addendum circle and the involute. Combine the addendum circle equation x 2 +y 2 =r A 2 , let the coordinates of point A be (x A ,y A ), and there is:

[0090] x A =r b Sinu k +r b u k cosu k y A =r b cosu A-r b u A Sinu A

[0091] Where r1=0.5mz=84mm r A =0.5(z+2h a *) m = 88 mm, u A is the angle of point A in the involute; r b =r1cosa=78.93mm, a is the standard pressure angle;

[0092] Solving the equation yields u A = 28.09°, substitute x A ,y A , find the coordinates of point A (71.28, 51.42), and the coordinates of point B are ((x A ,y A -Δl), that is, the coordinates of point B are (71.28, 51.392).

[0093] Point C coordinates: y C =y B -Δl=51.392, and y C =r b cosu C -r b u C Sinu C , find u C =28.11°, substitute

[0094] x C =r b Sinu C +r b u C cosu C =71.3281, and we get C(71.3281, 51.364).

[0095] The coordinates of point D, We get D(71.30405, 51.378). Finally, we connect the three points B, C, and D with a hyperbola, which is the shaping curve.

[0096] The following shows that the root stress and contact stress of the modified tooth are smaller:

[0097] According to the gear root stress calculation formula:

[0098]

[0099] Where Y Fa is the tooth form coefficient, so: Tooth shape factor Y Fa It is only related to the tooth profile shape and has nothing to do with the module. F When Y increases Fa The value decreases, the tooth root stress decreases, and the pitch circle pressure angle of the modified profile (the acute angle between the speed direction of the tooth profile rotating around the gear center at the intersection of the pitch circle and the positive pressure direction when meshing at this point) increases significantly; that is, the tooth root stress of the modified profile is reduced and the strength is higher.

[0100] According to Hertz theory, the contact stress is calculated

[0101] Where F is the normal force (N); L is the length of the contact line (mm); ρ1, θ2, are the radii of the two contacting gears (mm); E1, E2 are the elastic moduli of the two surface materials (MPa); v1, v2 are the Poisson's ratios of the two surface materials.

[0102] From the modified profile, we know that when meshing, the tooth top meshes with radius ρ3, ρ2<ρ3, so Substituting into the contact stress formula, σ H >σ H1 , σ H is the unmodified contact stress, σ H1 It is the contact stress after modification, so the contact stress after modification is smaller and the meshing impact is smaller.

[0103] 2. Radial deformation of the inner teeth of the friction plate

[0104] When radial deformation occurs to the inner teeth of the friction pair, Figure 3-5 As shown, a radial displacement compensation mechanism 1 is designed, and the radial displacement compensation mechanism 1 includes a magnetostrictive displacement sensor 2, a piezoelectric displacement stage 3, a guide rail 4, a slider 5, a piezoelectric ceramic displacement block 6, a push rod 7, an encoder 8, and a controller 9.

[0105] When compensating for the radial deformation of the friction plate, it is necessary to measure the radial displacement deformation of the friction plate. Since the space of the inner teeth of the friction plate is limited, a magnetostrictive displacement sensor is embedded in the inner teeth of the friction plate to measure the deformation of the inner teeth. The displacement is fed back to the controller through an encoder. The controller converts the displacement signal into an electrical signal. The piezoelectric ceramic receives the electrical signal and slides up and down together with the displacement stage, and the radial elastic deformation of the friction plate is compensated by the push rod on the displacement stage.

[0106] by Figure 5For example, the magnetostrictive displacement sensor 2 is arranged in the radial position of the friction plate; the L-shaped base 11 of the piezoelectric displacement stage 3 is fixed on the box 10; the guide rail 4 is vertically fixed on one plane of the L-shaped base 11 and parallel to the other plane of the L-shaped base 11; a slider 5 is sleeved on the guide rail 4, and the piezoelectric ceramic displacement block 6 is fixed on the right end face of the slider 5, and the push rod 7 is fixed on the left end face; one end of the push rod 7 is connected to the slider 5, and the other end of the push rod 7 is embedded in the inner diameter of the friction plate.

[0107] An encoder 8 and a controller 9 are also provided on the piezoelectric displacement stage 3 .

[0108] The waveguide tube of the detection element on the magnetostrictive displacement sensor is arranged inside the tooth top of the inner tooth of the friction plate, and the waveguide tube cannot protrude outside the tooth top of the inner tooth of the friction plate.

[0109] The radial displacement compensation mechanism of the friction plate is installed between the box body and the friction plate, and the radial displacement is compensated through the sliding length of the piezoelectric displacement stage according to the deformation feedback from the magnetostrictive displacement sensor.

[0110] 3. Deformation of the friction plate spline teeth in the direction of tooth thickness

[0111] When the inner and outer teeth of the friction plate are axially deformed, the displacement correction method is used to increase or decrease the tooth thickness for modification. According to the dish deformation law, the deformation of the inner and outer teeth of the friction plate is distributed in a positive and negative manner along the tooth thickness direction. The modification of the inner teeth of the friction plate is taken as an example. The modification curve is as follows: Figure 6 As shown in the figure, the tooth thickness increases the deformation after modification.

[0112] Next, we first calculate the axial deformation of the inner teeth of the friction plate. Given that the heat flux density q of the dual plate is 5.7383×10 5 (w / mm 2 ), the outer diameter b of the dual plate in the friction pair is 260 mm, the inner diameter a of the dual plate is 180 mm, the outer diameter b' of the friction plate is 250 mm, the inner diameter a' of the friction plate is 170 mm, and the viscosity μ of the lubricating oil is 0.03461 Pa·s. By changing the heat flux density, the inner and outer diameters of the friction plate, and the viscosity of the lubricating oil, and by curve fitting, the relationship between the deformation Δl' of the axial deformation of the inner tooth of the friction plate and the above parameters is obtained as follows:

[0113] Δl′=3.920-9.223*10 -8 q-0.853μ-0.16b′+0.002a′

[0114] Taking the 3mm thick friction plate as an example, according to the above functional relationship and its simulation results, the deformation Δl′ is 0.0026835mm. Figure 7 When machining gears, move the tool position outward from the standard position by a certain deformation distance ( Figure 7The dotted line position is moved to the solid line position), the original tooth thickness After the displacement, the tooth width on the tool pitch line increases by 2KJ compared with the tooth width on the indexing line. Since the wheel blank indexing circle and the tool pitch line are in pure rolling, the tooth thickness also increases by 2KJ. Therefore, the tooth thickness of the gear after the displacement is:

[0115] Where 2KJ = Δl′

[0116] The axial deformation of the external teeth is opposite to that of the internal teeth.

[0117] Depend on Figure 7 It is known that after the tool is displaced downward by the deformation distance, the tooth top height of the gear cut out in this way reduces the deformation distance. In order to satisfy the backlash-free engagement, the center distance must be increased. According to the relationship between the center distance and the engagement angle: a′cosa′=acosα, because cos is a decreasing function within the acute angle, the engagement angle increases, that is, the engagement angle a′>α.

[0118] Similarly, according to the gear root stress calculation formula: where a F =a′, that is, the root stress is reduced and the strength is higher.

[0119] The following explains that the extrusion stress on the tooth surface of the spline teeth after the internal teeth are modified is smaller:

[0120]

[0121] In the formula: σ—tooth surface extrusion stress (Pa); T—clutch rated torque (Nm); ζ—load unevenness coefficient between teeth, usually ζ=0.7~0.8; n—number of involute splines of internal tooth friction plate; h—working height of tooth (m); t—thickness of friction plate (m); a—number of internal tooth friction plates; d—pitch circle diameter (m).

[0122] It can be seen from the above formula that the extrusion stress of the spline teeth is inversely proportional to the thickness of the friction plate and the working height of the friction plate teeth. This repair method increases the thickness of the friction plate, so the extrusion stress on the tooth surface of the spline teeth is smaller after the repair.

[0123] The tooth profile after the axial internal teeth are repaired can compensate for the elastic deformation of the friction plate caused by the axial pressure and contact pressure between the friction pairs, ensuring the normal transmission of the friction plate.

[0124] The present invention takes into account the deformation and shaping of the friction plate under different working conditions, improves the tooth contact stress and extrusion stress, and solves the problem that the friction plate teeth can still transmit normally after being deformed under different working conditions.

[0125] In the description of the present application, it should be noted that the terms "left end", "right end", "radial", "axial", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0126] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A method for modifying the tooth profile of a friction plate in a liquid-viscous speed-regulating clutch, characterized in that: The specific steps include: Step 1, radial modification of external teeth: When radial deformation occurs to the external teeth of the friction plate, tooth top modification is adopted; the three coordinate points after modification are obtained by the intersection of the involute equation and the tooth top circle equation and the deformation amount, and the three points are connected by a hyperbola to obtain a modification curve, and radial repair of the external teeth is performed according to the modification curve; Step 2, radial shaping of the inner teeth: when radial deformation occurs to the inner teeth of the friction plate, a radial displacement compensation mechanism (1) is provided to compensate for the radial deformation and radial shaping of the inner teeth of the friction plate is performed; The deformation of the inner teeth is measured by a magnetostrictive displacement sensor (2) embedded in the teeth, and the displacement is fed back to the controller through an encoder; the controller drives the displacement table to slide up and down, and the radial elastic deformation of the friction plate is compensated by the sliding displacement of the displacement table; Step 3, axial modification of the inner teeth: When the inner teeth of the friction plate are axially deformed, the displacement correction method is used to increase the tooth thickness for repair; In step 1, when the outer teeth of the friction plate are radially deformed, the deformation amount Δl of the outer teeth of the friction plate is first calculated; Δl is obtained by curve fitting: Δl=4.355-1.198×10 -7 q-0.621μ-0.016b Among them, q is the heat flux density of the dual plate, b is the outer diameter of the friction plate, and μ is the viscosity of the lubricating oil.

2. The method for modifying the tooth profile of a friction plate in a liquid-viscous speed-regulating clutch according to claim 1, characterized in that: The coordinates of the intersection point A of the involute equation and the tooth top circle equation are (x A ,y A ); the three coordinate points after modification are B(x B ,y B )、C(x C ,y C )、D(x D ,y D ); Point B is the vertex coordinate of the shaping curve, and yB = yA-Δl, that is, the coordinate of point B is B(x A ,y A -Δl); The coordinates of point C are C(x C ,y C ), there is x C =rbsinu C +rbu C cosu C ,y C =rbcosu C -rbu C Sinu C , where rb is the pitch circle radius; and the ordinate y of point C C =y B -Δl; The coordinates of point D are 3. The method for modifying the tooth profile of a friction plate in a liquid-viscous speed-regulating clutch according to claim 1, characterized in that: The curvature radius of the modified curve is greater than the curvature radius of the original curve.

4. The method for modifying the tooth profile of a friction plate in a liquid-viscous speed-regulating clutch according to claim 1, characterized in that: In step 2, the radial displacement compensation mechanism (1) includes a magnetostrictive displacement sensor (2), a piezoelectric displacement stage (3), a guide rail (4), a slider (5), a piezoelectric ceramic displacement block (6), a push rod (7), an encoder (8), and a controller (9); The magnetostrictive displacement sensor (2) is arranged at a radial position of the friction plate; The L-shaped base (11) of the piezoelectric displacement stage (3) is fixed on the box (10); the guide rail (4) is vertically fixed on one plane of the L-shaped base (11) and is parallel to the other plane of the L-shaped base (11); a slider (5) is sleeved on the guide rail (4); a piezoelectric ceramic displacement block (6) is fixed on one end surface of the slider (5) and a push rod (7) is fixed on the other end surface; one end of the push rod (7) is connected to the slider (5), and the other end of the push rod (7) is embedded in the inner diameter of the friction plate; An encoder (8) and a controller (9) are also provided on the piezoelectric displacement stage (3).

5. The method for modifying the tooth profile of a friction plate in a liquid-viscous speed-regulating clutch according to claim 4, characterized in that: The waveguide tube of the detection element on the magnetostrictive displacement sensor is arranged inside the tooth top of the inner tooth of the friction plate, and the waveguide tube cannot protrude outside the tooth top of the inner tooth of the friction plate.

6. The method for modifying the tooth profile of a friction plate in a liquid-viscous speed-regulating clutch according to claim 1, characterized in that: In step 3, when the inner teeth of the friction plate are axially deformed, the deformation amount Δl′ of the inner teeth of the friction plate is first calculated; Δl′ is obtained by curve fitting: Δl′=3.920-9.223×10-8q-0.853μ-0.16b′+0.002a′, where q is the heat flux density of the dual plate, μ is the viscosity of the lubricating oil, a′ is the inner diameter of the friction plate, and b′ is the outer diameter of the friction plate.

7. The method for modifying the tooth profile of a friction plate in a liquid-viscous speed-regulating clutch according to claim 6, characterized in that: According to the dish deformation law, the deformation of the inner and outer teeth of the friction plate is distributed in a positive and negative manner along the tooth thickness direction. Take the modification of the inner teeth of the friction plate as an example: Original tooth thickness m is the module of the gear; When the tool position is moved outward by a distance of Δl′ from the standard position, the tooth width on the tool pitch line increases by 2KJ compared with the tooth width on the indexing line. 2KJ=Δl′, and the tooth thickness increases accordingly. The tooth thickness of the gear after the displacement is: The tooth thickness increases, the meshing angle increases, and the root stress decreases, thereby compensating for the radial deformation of the internal teeth.

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