Hydraulic retarder connected to front end of gearbox in parallel and torque control method of hydraulic retarder

Abstract

The invention relates to a hydraulic retarder connected to the front end of a gearbox in parallel and a torque control method thereof.The hydraulic retarder comprises a retarder shell, a retarder front cover and a retarder rear cover, the retarder front cover and the retarder rear cover are installed on the two sides of the retarder shell, and a working cavity and a gear train transmission mechanism are installed in the retarder shell; the gear train transmission mechanism comprises a driving wheel connected with the working cavity, a driving wheel in constant meshing connection with the driving wheel, a first retarder shaft and a second retarder shaft, the first retarder shaft and the second retarder shaft are coaxially installed with the driving wheel, the first retarder shaft penetrates through the front retarder cover and then is connected with the engine, and the second retarder shaft penetrates through the rear retarder cover and then is connected with the gearbox. The hydrodynamic retarder is connected to the input end of the gearbox in parallel, the speed ratio of different gears of the gearbox and the speed ratio of the retarder are utilized, the speed increasing and torque increasing adjusting range of the hydrodynamic retarder is enlarged, the hydrodynamic retarder can play a role in braking when a vehicle goes down a slope at a low speed, and the speed increasing and torque increasing effects of the vehicle are improved. And the optimal braking effect of the hydraulic retarder is achieved by adjusting the gear of the gearbox.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic retarders, and in particular relates to a hydraulic retarder connected in parallel to a front end of a gearbox and a torque control method thereof. Background Art

[0002] The existing post-mounted hydraulic retarder is installed at the output end of the gearbox, utilizing the retarder speed ratio (the retarder speed ratio refers to the speed ratio between the retarder and the gearbox) to increase the retarder speed and retarder torque. Generally, the post-mounted hydraulic retarder will only generate torque to act as a brake when the vehicle's speed is kept at a minimum of 30 km / h. To improve the braking effect of the post-mounted hydraulic retarder, the vehicle speed must be increased, allowing the retarder to operate at higher speeds to generate greater torque. Therefore, the post-mounted hydraulic retarder has high vehicle speed requirements and generally only works effectively within a speed range of 30-100 km / h. That is, at speeds below 30 km / h, the post-mounted hydraulic retarder generates little braking torque and poor braking effect.

[0003] Since the rear hydraulic retarder is also limited by the vehicle's load and the slope of the vehicle, for example, an 80-ton vehicle traveling on a 6% downhill slope must maintain a speed of at least 30 km / h to enable the rear hydraulic retarder to generate torque. However, a heavily loaded vehicle traveling downhill at 30 km / h can easily be dangerous. To improve downhill driving safety, the vehicle speed must be reduced to below 30 km / h, and the speed of the drive shaft will drop accordingly. Affected by the retarder speed ratio, the speed of the hydraulic retarder will also drop accordingly, resulting in the rear hydraulic retarder being unable to generate braking torque or the generated braking torque being very small and unable to play a braking role, which also affects the safe driving of the vehicle. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a hydraulic retarder connected in parallel to the front end of a gearbox.

[0005] The technical solution of the present invention is a hydraulic retarder connected in parallel to the front end of the gearbox, comprising a retarder housing, a retarder front cover and a retarder rear cover installed on both sides of the retarder housing, a working chamber and a gear train transmission mechanism installed in the retarder housing, the gear train transmission mechanism comprising a driving wheel connected to the working chamber, a driving wheel constantly meshed with the driving wheel, and a retarder first shaft and a retarder second shaft coaxially installed with the driving wheel, the retarder first shaft passing through the retarder front cover and connected to the engine, the retarder second shaft passing through the retarder rear cover and connected to the gearbox.

[0006] As preferred, the front end of the second shaft of the retarder is at least partially inserted into the groove at the end of the first shaft of the retarder to form coaxial rotation at the same speed, the driving wheel is sleeved at the joint position of the first shaft and the second shaft of the retarder, the external spline at the end of the first shaft of the retarder is at least partially engaged with the internal spline of the driving wheel, and the second shaft of the retarder is connected with at least part of the internal spline of the driving wheel through a connecting gear sleeve; the first shaft of the retarder is connected with the front cover of the retarder through a first shaft bearing, a first bearing snap spring is arranged on the outer ring of the first shaft bearing, a first snap spring groove is arranged on the first shaft near the inner ring of the first shaft bearing, a second bearing snap spring is arranged in the first snap spring groove, the second shaft of the retarder is connected with the rear cover of the retarder through a second shaft bearing, a third bearing snap spring is arranged on the outer ring of the second shaft bearing, and a second snap spring groove is arranged on the second shaft near the inner ring of the second shaft bearing, wherein a fourth bearing snap spring is arranged in the second snap spring groove.

[0007] As preferred, the front end of the second shaft of the retarder is at least partially inserted into the groove at the end of the first shaft of the retarder to form coaxial rotation at the same speed, the driving wheel is sleeved at the joint position of the first shaft and the second shaft of the retarder, the external spline at the end of the first shaft of the retarder is at least partially engaged with the internal spline of the driving wheel, and the second shaft of the retarder is connected with at least part of the internal spline of the driving wheel through a connecting gear sleeve; the first shaft of the retarder is connected with the front cover of the retarder through a first shaft bearing, a first bearing snap spring is arranged on the outer ring of the first shaft bearing, a first snap spring groove is arranged on the first shaft near the inner ring of the first shaft bearing, a second bearing snap spring is arranged in the first snap spring groove, the second shaft of the retarder is connected with the rear cover of the retarder through a second shaft bearing, a third bearing snap spring is arranged on the outer ring of the second shaft bearing, and a second snap spring groove is arranged on the second shaft near the inner ring of the second shaft bearing, wherein a fourth bearing snap spring is arranged in the second snap spring groove.

[0008] As preferred, the diameter of the driving wheel is greater than that of the driving wheel, so that the speed ratio of the driving wheel to the driving wheel is greater than 1.

[0009] As preferred, the diameter of the driving wheel is greater than that of the driving wheel, so that the speed ratio of the driving wheel to the driving wheel is greater than 1.

[0010] As preferred, the wheel train transmission mechanism further comprises an idler wheel connected with the driving wheel, the idler wheel is symmetrically arranged on both sides of the driving wheel, the center distance between the driving wheel and the idler wheel is equal to the center distance between the driving wheel and the driving wheel, the idler wheel is sleeved on the front end of the third shaft of the retarder which is arranged in parallel with the first shaft and the second shaft of the retarder, and the rear end of the third shaft of the retarder is fixed with the connecting plate arranged in the retarder shell.

[0011] As preferred, the oil inlet and the oil outlet of the working chamber are respectively provided with a retarder oil inlet pipe and a retarder oil outlet pipe, one end of the retarder oil inlet pipe and the retarder oil outlet pipe penetrates through the retarder shell and is connected with the oil storage cavity through a flexible oil pipe, a one-way valve is arranged on the oil outlet of the working chamber; a temperature sensor is arranged in the retarder oil outlet pipe for sensing the temperature of the returned oil in the retarder oil outlet pipe, the oil flowing out of the oil outlet of the working chamber is first cooled by the heat exchanger and then returned to the oil storage cavity; a retarder exhaust pipe is arranged on the working chamber, and the retarder exhaust pipe is connected with the oil-gas separator through an exhaust hose.

[0012] Preferably, the working cavity comprises a working cavity front cover, a working cavity rear cover, and a containing cavity enclosed by the working cavity front cover and the working cavity rear cover, the containing cavity is provided with a stator, a rotor, and a rotor shaft, the rotor shaft is coaxially installed with the driving wheel through the working cavity front cover, and the rear end of the rotor shaft is connected with a retarder oil pump assembly, the oil pump cover of the retarder oil pump assembly is fixed to the outside of the working cavity rear cover, the oil pump cover is provided with an oil inlet hole, the oil inlet hole is communicated with an oil storage cavity through a lubricating oil inlet pipe, and the working cavity front cover is connected with a lubricating oil return pipe and a retarder oil outlet pipe.

[0013] Another technical solution of the present application is a torque control method of the hydraulic retarder connected in parallel with the front end of the gearbox, which comprises the following steps:

[0014] Step 1: when the vehicle needs to work, the hydraulic retarder is started;

[0015] Step 2: the vehicle transmission shaft speed is calculated according to the vehicle downhill speed;

[0016] Step 3: the hydraulic retarder speed is calculated according to the vehicle transmission shaft speed, the retarder speed ratio, and the speed ratio of the current gear of the gearbox;

[0017] Step 4: the retarder torque corresponding to the hydraulic retarder speed is obtained, the transmission shaft torque formed by the hydraulic retarder transmitted to the transmission shaft through the gearbox is calculated according to the hydraulic retarder torque, the retarder speed ratio, and the speed ratio of the current gear of the gearbox;

[0018] Step 5: whether the transmission shaft torque is in the optimal torque range is judged, if not, return to Step 3 through Step 6; if yes, enter Step 6;

[0019] Step 6: the gear of the gearbox is adjusted;

[0020] Step 7: the current gear of the gearbox is maintained;

[0021] Step 8: when the vehicle does not need to work, the hydraulic retarder is turned off.

[0022] Preferably, the calculation formula of the hydraulic retarder speed in Step 3 is as follows:

[0023] n 缓 = n 轴 *g1*g2;

[0024] In the formula, n 缓 is the retarder speed, n 轴 is the transmission shaft speed, g1 is the retarder speed ratio, and g2 is the speed ratio of the current gear of the gearbox.

[0025] The calculation formula of the transmission shaft torque in Step 4 is as follows:

[0026] T 轴 = T 缓 *g1*g2;

[0027] In the formula, T 轴 is the transmission shaft torque, T 缓 is the retarder torque, g1 is the retarder speed ratio, and g2 is the speed ratio of the current gear of the gearbox.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] (1) By connecting the hydraulic retarder in parallel with the input end of the gearbox, the speed ratio of different gears of the gearbox and the speed ratio of the retarder are used to expand the adjustment range of the speed increase and torque increase of the hydraulic retarder, so that the hydraulic retarder can play a braking role when the vehicle is descending at low speed (especially when the vehicle speed is 5-30 km / h); at the same time, by adjusting the gear of the gearbox, the transmission shaft torque formed by the transmission of the gearbox to the transmission shaft can be adjusted to reach the optimal torque range, and the transmission shaft torque is applied to the wheels through the axle, thereby realizing the best braking effect.

[0030] (2) By connecting the hydraulic retarder in parallel with the input end of the gearbox, using the speed ratio of the 12 gears of the gearbox, the hydraulic retarder can play a braking role when the downhill speed is controlled at 5 km / h, while the engine speed is not high, and the heat energy generated by the retarder is small, thereby reducing the burden on the engine cooling system. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a perspective view of the hydraulic retarder of the present application connected in parallel with the front end of the gearbox;

[0032] Figure 2 is a perspective view from another angle; Figure 1

[0033] Figure 3 is an exploded view of the hydraulic retarder of the present application connected in parallel with the front end of the gearbox;

[0034] Figure 4 is an exploded view from another angle; Figure 3

[0035] Figure 5 is a connection diagram of the hydraulic retarder and the oil storage cavity of the present application;

[0036] Figure 6 is a connection diagram between the retarder one shaft, the retarder two shaft and the driving wheel in the present application; Figure 1

[0037] Figure 7 Figure 6 ​​​​The schematic diagram of the A-A section of the hydraulic retarder;

[0038] Figure 8 The schematic diagram of the B-B section of the hydraulic retarder; Figure 1 The schematic diagram of the connection between the driving wheel, the driving wheel and the idler wheel of the hydraulic retarder;

[0039] Figure 9 The schematic diagram of the working chamber of the hydraulic retarder; Figure 1 The schematic diagram of the working chamber of the hydraulic retarder;

[0040] Figure 10 The schematic diagram of the working chamber of the hydraulic retarder; Figure 9 The schematic diagram of the B-B section of the hydraulic retarder;

[0041] Figure 11 The schematic diagram of the working chamber of the hydraulic retarder when the hydraulic retarder is not working;

[0042] Figure 12 The schematic diagram of the working chamber of the hydraulic retarder when the hydraulic retarder is working;

[0043] Figure 13 The schematic diagram of the connection between the hydraulic retarder, the gearbox and the engine of the hydraulic retarder;

[0044] Figure 14 The flow chart of the torque control method of the hydraulic retarder of the present application.

[0045] Explanation of the symbols of the main components:

[0046] Retarder housing 1; Retarder front cover 11; Retarder rear cover 12; Connecting plate 13;

[0047] Working chamber 2; Working chamber front cover 21; Working chamber rear cover 22; Retarder oil inlet pipe 221; Retarder oil outlet pipe 222; Flexible oil pipe 223; Oil return one-way valve 23; Stator 24; Rotor 25; Rotor shaft 26; Retarder oil pump assembly 27; Oil pump cover 271; Oil inlet hole 2711; Lubricating oil inlet pipe 272; Lubricating oil return pipe 28; Retarder exhaust pipe 29; Exhaust hose 291;

[0048] Wheel train transmission mechanism 3; Driving wheel 31; Driving wheel 32; Retarder first shaft 33; Groove 331; First shaft bearing 332; First bearing snap spring 333; First snap spring groove 334; Second bearing snap spring 335; Retarder second shaft 34; Connecting bearing 341; Second shaft bearing 342; Third bearing snap spring 343; Second snap spring groove 344; Fourth bearing snap spring 345; Connecting gear sleeve 35; Idler wheel 36; Retarder third shaft 37;

[0049] Oil storage chamber 4;

[0050] Oil and gas separator 5. DETAILED DESCRIPTION

[0051] The present application will be further described in detail below with reference to the accompanying drawings:

[0052] Referring to Figures 1 to 5 As shown in the figure, the application provides a hydraulic retarder connected in parallel with the front end of the gearbox, which comprises a retarder housing 1, a retarder front cover 11 and a retarder rear cover 12 installed on both sides of the retarder housing 1, a working cavity 2 and a gear train 3 installed in the retarder housing 1, the gear train 3 comprising a driving wheel 31 connected with the working cavity 2, a driving wheel 32 connected with the driving wheel 31 in constant engagement, and a retarder one shaft 33 and a retarder two shaft 34 coaxially installed with the driving wheel 32, the retarder one shaft 33 being connected with the engine after passing through the retarder front cover 11, and the retarder two shaft 34 being connected with the gearbox after passing through the retarder rear cover 12. By connecting the hydraulic retarder in parallel with the input end of the gearbox, the speed ratio of different gears of the gearbox and the speed ratio of the retarder can be utilized to amplify the speed of the vehicle transmission shaft by different multiples, thereby expanding the adjustment range of the speed and torque increase of the hydraulic retarder, so that the hydraulic retarder can play a braking role when the vehicle is running downhill at low speed (especially when the vehicle speed is 5-30 km / h), and the retarder can achieve the best braking effect by adjusting the gear position of the gearbox.

[0053] It should be noted that the driving wheel 32 and the retarder one shaft 33 can be designed as two separate components connected together by assembly; the driving wheel 32 and the retarder one shaft 33 can also be designed as an integrated structure formed by processing.

[0054] Referring to Figure 6 , Figure 7 As shown in the figure, the front end of the retarder two shaft 34 is at least partially inserted into the groove 331 formed at the end of the retarder one shaft 33 to form coaxial and synchronous rotation, the driving wheel 32 is sleeved at the joint position of the retarder one shaft 33 and the retarder two shaft 34, and Figure 7 As shown in the figure, the external spline at the end of the retarder one shaft 33 is at least partially engaged with the internal spline of the driving wheel 32, and the retarder two shaft 34 is connected with the internal spline of the driving wheel 32 through the connecting spline sleeve 35, so that the driving wheel 32, the retarder one shaft 33 and the retarder two shaft 34 are connected together through the connecting spline sleeve 35.

[0055] It should be noted that since the connecting spline sleeve 35 is sleeved at the front end of the retarder two shaft 34, the internal spline of the connecting spline sleeve 35 is engaged with the spline of the retarder two shaft 34, and the external spline of the connecting spline sleeve 35 is at least partially engaged with the internal spline of the driving wheel 32; the driving wheel 31 transmits the braking torque generated by the retarder to the driving wheel 32, the driving wheel 32 transmits the braking torque to the retarder two shaft 34 through the connecting spline sleeve 35, and the retarder two shaft 34 transmits the braking torque to the gearbox, so as to realize the transmission of the braking torque.

[0056] In the embodiment, the front end of the retarder two-shaft 34 is also sleeved with a connecting bearing 341, the front end of the retarder two-shaft 34 is nested in the groove 331 at the end of the retarder one-shaft 33 through the connecting bearing 341, the inner ring of the connecting bearing 341 is sleeved with the front end of the retarder two-shaft 34, and the outer ring abuts against the inner wall of the groove 331 of the retarder one-shaft 33.

[0057] It should be noted that, since the inner ring of the connecting bearing 341 is in interference fit with the retarder two-shaft 34, and the outer ring is in clearance fit with the inner wall of the groove 331 of the retarder one-shaft 33, the connecting bearing 341 is fixed between the retarder one-shaft 33 and the retarder two-shaft 34, the connecting bearing 341 does not rotate alone, but rotates together with the retarder one-shaft 33 and the retarder two-shaft 34, the connecting bearing 341 realizes the accurate coaxial and concentric positioning between the retarder one-shaft 33 and the retarder two-shaft 34, avoids radial deviation or vibration, and effectively ensures the consistency and stability of the concentric and coaxial rotation of the two shafts; the connecting bearing 341 also plays a guiding role, and the radial force is transmitted along the preset path through the rigid support of the bearing, preventing the axial deviation caused by local stress concentration.

[0058] Please refer to Figure 1 It is shown that the retarder one-shaft 33 is connected with the retarder front cover 11 through a one-shaft bearing 332, as Figure 6 It is shown that the outer ring of the one-shaft bearing 332 is provided with a first bearing snap spring 333, so as to fix the one-shaft bearing 332 with the retarder front cover 11 and prevent the one-shaft bearing 332 from moving together; the retarder one-shaft 33 is provided with a first snap spring groove 334 at a position close to the inner ring of the one-shaft bearing 332, and the first snap spring groove 334 is provided with a second bearing snap spring 335, so as to prevent the retarder one-shaft 33 from moving axially.

[0059] Please refer to Figure 1 It is shown that the retarder two-shaft 34 is connected with the retarder rear cover 12 through a two-shaft bearing 342, as Figure 6 It is shown that the outer ring of the two-shaft bearing 342 is provided with a third bearing snap spring 343, so as to fix the two-shaft bearing 342 with the retarder rear cover 12 and prevent the two-shaft bearing 342 from moving together, and the retarder two-shaft 34 is provided with a second snap spring groove 344 at a position close to the inner ring of the two-shaft bearing 342, and the second snap spring groove 344 is provided with a fourth bearing snap spring 345, so as to prevent the retarder two-shaft 34 from moving axially.

[0060] Please refer to Figure 8As shown, the diameter of the driving wheel 31 is greater than that of the driving wheel 32, so that the rotational speed ratio of the driving wheel 32 to the driving wheel 31 is greater than 1, and the purpose of the rotational speed ratio greater than 1 is to play the role of increasing the speed and torque of the retarder. The general speed ratio of the retarder includes: 1:1.28, 1:1.3, 1:2, 1:2.138, etc., and the corresponding speed ratio of the hydraulic retarder can be selected according to the requirements of the vehicle model and installed; in this embodiment, the rotational speed ratio of the driving wheel 32 to the driving wheel 31 is 1:1.3.

[0061] It should be noted that the hydraulic retarder can also be designed with a rotational speed ratio of the driving wheel 32 to the driving wheel 31 less than 1, for example: the rotational speed ratio of the driving wheel 32 to the driving wheel 31 is 1:0.9, to meet the use requirements.

[0062] Further, the wheel train transmission mechanism 3 further comprises an idler wheel 36 connected with the driving wheel 32 in constant engagement, as shown in Figure 8 As shown, the idler wheel 36 is symmetrically arranged on both sides of the driving wheel 32, and the center distance between the driving wheel 32 and the idler wheel 36 is equal to the center distance between the driving wheel 32 and the driving wheel 31. In this embodiment, the center distance between the driving wheel 32 and the driving wheel 31 and the center distance between the driving wheel 32 and the idler wheel 36 are both 155 mm.

[0063] It is worth noting that by arranging the idler wheel 36, it not only plays a role of centering and stabilizing, ensures that the driving wheel 32 always rotates around the retarder first shaft 33, maintains the center distance of gear engagement, and avoids eccentricity; but also can improve the engagement condition, support the driving wheel 32 through auxiliary support, optimize the gear engagement state of the driving wheel 32, the driving wheel 31, the retarder first shaft 33 and the connecting gear sleeve 35, improve the engagement precision and reduce the wear; it can also play the role of auxiliary support, enhance the stability of the driving wheel 32, make up for the problem of unstable rotation caused by the suspension characteristics when there is no idler wheel, and reduce the risk of eccentric wear.

[0064] Please refer to Figure 3 , Figure 4 As shown, the idler wheel 36 is arranged on the front end of the retarder third shaft 37 which is arranged in parallel with the retarder first shaft 33 and the retarder second shaft 34, and the rear end of the retarder third shaft 37 is fixed with the connecting plate 13 arranged in the retarder housing 1. Since the idler wheel 36 is connected with the retarder third shaft 37 through the bearing, the retarder third shaft 37 does not rotate by itself, and the bearing rotates with the idler wheel 36, therefore, the idler wheel 36 is only used for support and centering, and does not transmit power.

[0065] In other embodiments, the idler wheel 36 is arranged on the front end of the retarder third shaft 37, and the rear end of the retarder third shaft 37 is connected with the connecting plate 13 through the bearing. The outer ring of the bearing is fixed with the connecting plate 13, and the inner ring of the bearing can rotate with the retarder third shaft 37, so that the retarder third shaft 37 rotates synchronously with the idler wheel 36.

[0066] It should be noted that the idler 36 and the retarder three-shaft 37 can be designed as two separate components connected together by assembly; the idler 36 and the retarder three-shaft 37 can also be designed as an integrated structure formed by machining.

[0067] Please refer to Figure 9 As shown, the oil inlet and the oil outlet of the working cavity 2 are respectively provided with a retarder oil inlet pipe 221 and a retarder oil outlet pipe 222, and the retarder oil inlet pipe 221 and the retarder oil outlet pipe 222 are connected to the oil storage cavity 4 through a flexible oil pipe 223. Figure 5 As shown, one end of the retarder oil inlet pipe 221 and the retarder oil outlet pipe 222 passes through the retarder housing 1 and is connected to the oil storage cavity 4 through the flexible oil pipe 223.

[0068] It should be noted that since the working cavity 2 and the oil storage cavity 4 are designed as a split structure, the problem of large volume of the hydraulic retarder due to the integrated structure of the working cavity 2 and the oil storage cavity 4 in the prior art can be effectively solved. After the working cavity 2 and the oil storage cavity 4 are split, the working cavity 2 is installed in the retarder housing 1, and the oil storage cavity 4 can be installed according to the vehicle structure and other conditions, for example, the oil storage cavity 4 is installed behind the gearbox or on the vehicle frame, etc.; the working cavity 2 and the oil storage cavity 4 are connected through the flexible oil pipe 223, and the length of the flexible oil pipe 223 can be customized according to the distance between the working cavity 2 and the oil storage cavity 4, thereby effectively improving the convenience of installation of the hydraulic retarder.

[0069] In this embodiment, in order to improve the convenience of installation of the flexible oil pipe 223, the retarder oil outlet pipe 222 is designed with two connection ports for connecting the flexible oil pipe 223, and the two connection ports are located above and below the hydraulic retarder respectively. When one of the connection ports is connected to the oil storage cavity 4 through the flexible oil pipe 223, the other connection port which is not connected to the oil storage cavity 4 can be reserved for maintenance and repair.

[0070] Please refer to Figure 10 As shown, the oil outlet of the working cavity 2 is provided with an oil return check valve 23, which is arranged to ensure that the oil in the working cavity 2 can only flow out of the working cavity 2 in one direction, preventing reverse flow of the oil, avoiding unintended damping effect or starting failure. When the hydraulic retarder is working, the oil pressure in the working cavity 2 pushes the valve core to overcome the spring force, so that the valve is opened and the oil is smoothly discharged; when the hydraulic retarder is not working, the spring is automatically reset, and the valve is closed under the action of the spring to ensure sealing, so as to prevent the oil in the oil storage cavity 4 from entering the working cavity 2 due to gravity, and to ensure that there is no oil residue in the hydraulic retarder in the non-working state.

[0071] In this embodiment, because the oil reservoir 4 is located higher than the working chamber 2, without the oil return check valve 23 installed, when the hydraulic retarder is not operating, the pressure in the working chamber 2 is too low, and the oil in the oil reservoir 4 enters the working chamber 2 through the oil return port due to gravity, resulting in increased resistance during vehicle startup, or even a failure to start normally. This can also cause the retarder to brake while the vehicle is in motion. Installing the oil return check valve 23 at the oil return port effectively prevents this problem, ensuring smooth vehicle startup and normal operation.

[0072] Since the temperature of the return oil in the working chamber 2 is very high, a temperature sensor (not shown in the figure) is installed in the retarder oil outlet pipe 222 to sense the temperature of the return oil in the retarder oil outlet pipe 222. The oil flowing out of the oil outlet of the working chamber 2 first passes through the heat exchanger to lower the temperature, and then flows back to the oil storage chamber 4, waiting for the next use.

[0073] See also Figures 11 to 12 As shown, the working chamber 2 includes a working chamber front cover 21, a working chamber rear cover 22 and an accommodating chamber formed by the working chamber front cover 21 and the working chamber rear cover 22. A stator 24, a rotor 25 and a rotor shaft 26 are provided in the accommodating chamber. The front end of the rotor shaft 26 passes through the working chamber front cover 21 and is coaxially installed with the driving wheel 31.

[0074] It should be noted that the driving wheel 31 and the rotor shaft 26 can be designed as two separate components and connected together by assembly; the driving wheel 31 and the rotor shaft 26 can also be designed as an integrated structure formed by processing.

[0075] like Figure 11 As shown, when the hydraulic retarder is not operating, a large gap exists between stator 24 and rotor 25. Working chamber 2 is either completely empty of oil or contains minimal oil. Rotor 25 rotates freely along rotor shaft 26, while the stator remains stationary. Because working chamber 2 lacks a closed oil circulation channel, rotor 25 generates virtually no hydraulic resistance during rotation. The hydraulic retarder is in an "idling" state, providing no braking torque.

[0076] like Figure 12 As shown, when the hydraulic retarder is working, the working chamber 2 is filled with oil, forming a closed oil circulation loop. The rotor 25 and the blades of the stator 24 are tightly matched, and the oil enters between the stator 24 and the rotor 25. When the rotor 25 rotates at high speed along with the rotor shaft 26, it pushes the oil to impact the blades of the stator 24 to form a liquid vortex, so that the retarder generates a braking torque and forms damping. The driving wheel 31 transmits the braking torque of the retarder to the driving wheel 32, and the driving wheel 32 transmits it to the retarder second shaft 34 through the connecting gear sleeve 35. The retarder second shaft 34 transmits it to the gearbox, and then transmits it to the vehicle drive shaft through the output shaft of the gearbox, and then transmits it to the wheels through the drive shaft, thereby playing a braking role and slowing down the vehicle.

[0077] Please refer to Figure 9 、 Figure 11 、 Figure 12 As shown in the drawings, the rear end of the rotor shaft 26 is connected with a retarder oil pump assembly 27, the oil pump cover 271 of the retarder oil pump assembly 27 is fixed to the outside of the rear cover 22 of the working chamber, and the oil inlet hole 2711 is formed in the oil pump cover 271, as shown in Figure 4 、 Figure 5 The oil inlet hole 2711 is communicated with the oil storage chamber 4 through the lubricating oil inlet pipe 272. In this embodiment, the lubricating oil inlet pipe 272 is a Φ10mm oil pipe which communicates the retarder oil pump assembly 27 and the oil storage chamber 4. The retarder oil pump assembly 27 pumps the oil in the oil storage chamber 4 into the working chamber 2 through continuous rotation, provides continuous lubrication for the rotor shaft bearing, and fills the gap between the stator 24, the rotor 25 and the rotor shaft 26 with lubricating oil, thereby enhancing the sealing of the rotating parts. By installing the retarder oil pump assembly 27, the response time of the hydraulic retarder can also be effectively shortened.

[0078] Please refer to Figure 4 The lubricating oil return pipe 28 is connected between the front cover 21 of the working chamber and the retarder oil outlet pipe 222, and the lubricating oil flows back to the retarder oil outlet pipe 222 through the lubricating oil return pipe 28, and then flows back to the oil storage chamber 4 through the retarder oil outlet pipe 222.

[0079] Please refer to Figure 3 、 Figure 5 、 Figure 9 The working chamber 2 is provided with a retarder exhaust pipe 29, and the retarder exhaust pipe 29 is connected with the oil-gas separator 5 through the exhaust hose 291 to realize gas discharge and pressure maintenance of the working chamber 2. When the hydraulic retarder is not working, as shown in Figure 11 The rotor 25 and the stator 24 are in a separated state and are communicated with the atmosphere; when the retarder is working, the oil enters the working chamber 2 to push the rotor 25 to move until it cannot move, as shown in Figure 12 At this time, there is only about 2mm gap between the rotor 25 and the stator 24, and during the movement process, the retarder exhaust pipe 29 quickly discharges the air in the chamber to ensure that the oil fully fills the working chamber 2, avoiding the influence of air resistance on the torque transmission efficiency; since the retarder exhaust pipe 29 is connected with the oil-gas separator 5, after the exhaust is completed, the oil-gas separator 5 automatically closes the pipeline to prevent external air backflow or internal oil leakage, maintain the required pressure of the working chamber, and ensure the normal generation of braking torque of the hydraulic retarder.

[0080] Please refer to Figure 13 The working principle of the hydraulic retarder provided by the present application connected in parallel with the front end of the gearbox is as follows:

[0081] Generally, the hydraulic retarder starts to work when the vehicle is downhill, and the engine does not work; at this time, the high speed of the engine is formed by the rotation of the wheel F, the wheel speed is transmitted to the axle E, the axle E is transmitted to the gearbox C through the transmission shaft D, and the gearbox C transmits the speed to the engine A.

[0082] The hydraulic retarder B is connected in parallel to the input end of the gearbox C, the transmission shaft speed is transmitted to the gearbox C, and the speed ratio of different gears of the gearbox C and the speed ratio of the retarder can amplify the transmission shaft speed by different multiples, thereby expanding the adjustment range of the speed increase and torque increase of the hydraulic retarder B; at the same time, the brake torque generated by the retarder is synchronously transmitted to the gearbox C through the wheel train transmission mechanism 3, and the brake torque of the retarder can be amplified by the corresponding multiple through the speed ratio of the retarder and the current gear speed ratio of the gearbox C, and then transmitted to the transmission shaft D, and the transmission shaft D is transmitted to the wheel F through the axle E, thereby playing a braking role and slowing down the vehicle.

[0083] The hydraulic retarder connected in parallel to the front end of the gearbox can expand the adjustment range of the speed increase and torque increase of the hydraulic retarder by using the speed ratio of different gears of the gearbox and the speed ratio of the retarder, thereby realizing the braking effect of the hydraulic retarder when the vehicle is downhill at low speed (especially when the vehicle speed is 5-30 km / h); at the same time, by adjusting the gear position of the gearbox, the transmission shaft torque formed by the transmission shaft D through the gearbox can be adjusted to reach the best torque interval, and the transmission shaft torque acts on the wheel F through the axle E, thereby realizing the best braking effect.

[0084] The application also provides a torque control method of the hydraulic retarder connected in parallel to the front end of the gearbox, as shown in the accompanying drawings, the torque control method comprises the following steps: Figure 14

[0085] Step 1: when the vehicle needs the hydraulic retarder to work, the hydraulic retarder is started;

[0086] Step 2: the transmission shaft speed of the vehicle is calculated according to the downhill speed of the vehicle;

[0087] Step 3: the hydraulic retarder speed is calculated according to the transmission shaft speed of the vehicle, the speed ratio of the retarder and the speed ratio of the current gear of the gearbox;

[0088] Step 4: the retarder torque corresponding to the hydraulic retarder speed is obtained, and the transmission shaft torque formed by the hydraulic retarder through the gearbox is calculated according to the hydraulic retarder torque, the speed ratio of the retarder and the speed ratio of the current gear of the gearbox;

[0089] Step 5: whether the transmission shaft torque is in the best torque interval is judged, if not, return to step 3 through step 6; if yes, enter step 7;

[0090] ​Step ⑹: adjusting the gear of the gearbox;

[0091] Step ⑺: maintaining the current gear of the gearbox;

[0092] Step ⑻: closing the hydraulic retarder when the vehicle does not need the hydraulic retarder to work.

[0093] As preferred, the calculation formula of the hydraulic retarder rotating speed in step ⑶ is as follows:

[0094] n 缓 = n 轴 *g1*g2;

[0095] In the formula, n 缓 is the retarder rotating speed, n 轴 is the transmission shaft rotating speed, g1 is the retarder speed ratio, and g2 is the speed ratio of the current gear of the gearbox.

[0096] The calculation formula of the transmission shaft torque in step ⑷ is as follows:

[0097] T 轴 = T 缓 *g1*g2;

[0098] In the formula, T 轴 is the transmission shaft torque, T 缓 is the retarder torque, g1 is the retarder speed ratio, and g2 is the speed ratio of the current gear of the gearbox.

[0099] The speed ratios of the 12-gear gearbox on a general heavy-duty vehicle are shown in Table 1:

[0100] Table 1

[0101] Gear 1 2 3 4 5 6 7 8 9 10 11 12 Gear ratio g2 1:12.1 1:9.41 1:7.31 1:5.71 1:4.46 1:3.48 1:2.71 1:2.11 1:1.64 1:1.28 1：1 1:0.78

[0102] It should be noted that the rear-mounted hydraulic retarder in the prior art is installed at the output end of the gearbox, and it can only amplify the retarder rotating speed and the retarder torque by using the retarder speed ratio, and the adjustable range of the retarder speed and torque is small.

[0103] The front-mounted hydraulic retarder provided by the present application is connected in parallel to the input end of the gearbox, and the retarder rotating speed and the retarder torque are amplified by using the speed ratios of different gears of the gearbox and the retarder speed ratio. Since the gearbox has 12 gear speed ratios that can be adjusted, the adjustable range of the hydraulic retarder speed and torque is expanded, and the braking effect is multiplied by the rear-mounted hydraulic retarder.

[0104] For example, in the case of the same load, the same slope, and the vehicle speed of 5 km / h, 8 km / h, 10 km / h, 15 km / h, and 30 km / h, the braking effect of the hydraulic retarder provided in parallel with the front end of the gearbox of the present application and the rear-mounted hydraulic retarder in the prior art is compared and analyzed as follows:

[0105] I. According to the vehicle speed V 车 Obtain the transmission shaft speed n 轴 .

[0106] The vehicle speed V 车 and the transmission shaft speed n 轴 The calculation formula between them is:

[0107] n 轴 = i*n 轮

[0108] In the formula, n 轴 is the transmission shaft speed, with units of revolutions per minute (r / min); n 轮 is the wheel speed, with units of revolutions per minute (r / min); V 车 is the vehicle speed, with units of meters per hour (m / h); D 轮 is the wheel diameter, with units of meters (m); i is the transmission ratio; wherein D 轮 is 1.2 m, and i is 5.26.

[0109] As shown in Table 2, the transmission shaft speed is calculated when the vehicle speed is 5 km / h, 8 km / h, 10 km / h, 15 km / h, and 30 km / h.

[0110] Table 2

[0111]

[0112]

[0113] II. Analysis of the rear-mounted hydraulic retarder speed, the rear-mounted hydraulic retarder torque, and the transmission shaft torque.

[0114] Table 3-1 and Table 3-2 are the experimental data comparison tables of the transmission shaft speed, the rear-mounted hydraulic retarder speed, and the retarder torque in the prior art:

[0115] Table 3-1

[0116] Transmission shaft speed (r / min) 200 300 400 500 600 750 800 900 950 1000 Retarder speed (r / min) 400 600 800 1000 1200 1500 1600 1800 1900 2000 Retarder torque (Nm) 200 610 1200 1790 2422 3150 3200 3300 3300 3280

[0117] Table 3-2

[0118] Transmission shaft speed (r / min) 1100 1250 1400 1500 1600 1700 1900 2100 2300 2500 Retarder speed (r / min) 2200 2500 2800 3000 3200 3400 3800 4200 4600 5000 Retarder torque (Nm) 3200 3150 3100 2900 2650 2528 2262 2047 1869 1719

[0119] It should be noted that the retarder speed ratio used in Tables 3-1 and 3-2 is 1:2, that is, the speed ratio between the rear hydraulic retarder and the transmission is 1:2. Therefore, the retarder speed and retarder torque in Tables 3-1 and 3-2 are the values ​​after speed increase and torque increase.

[0120] When the vehicle's downhill speed is 5km / h, 8km / h, 10km / h, 15km / h, and 30km / h respectively, the speed n of the rear hydraulic retarder is 缓 The calculation formula is: 缓 =n 轴 *g1, where n 缓 is the retarder speed, n 轴 is the transmission shaft speed, g1 is the retarder speed ratio, and the corresponding retarder speed n can be calculated 缓 , combined with the rear hydraulic retarder data comparison table in Table 3-1 and Table 3-2, the corresponding retarder torque T can be obtained. 缓 , and retarder torque T 缓 The transmission shaft torque T acting on the transmission shaft 轴 , thus obtaining the retarder speed n under different vehicle speed conditions shown in Table 4 缓 , retarder torque T 缓 and the drive shaft torque T 轴 .

[0121] Table 4

[0122]

[0123]

[0124] It should be noted that in the prior art, when the vehicle's downhill speed is lower than 30 km / h, the braking torque generated by the rear hydraulic retarder is small and the braking effect is poor. As shown in Table 4, the vehicle's downhill speed V 车 When the speed reaches 30km / h, the retarder torque and the drive shaft torque can reach 2422Nm to play a certain braking role.

[0125] 3. Analysis of the speed, torque and transmission shaft torque of the pre-hydraulic retarder.

[0126] Since the retarder speed ratio in Tables 3-1 and 3-2 is 1:2, the retarder speed and retarder torque are both magnified by 2 times. Therefore, the data comparison tables between the drive shaft speed, hydraulic retarder speed, and hydraulic retarder torque when the retarder does not increase speed are shown in Tables 5-1 and 5-2.

[0127] Table 5-1

[0128] Transmission shaft speed (r / min) 200 300 400 500 600 750 800 900 950 1000 Retarder speed (r / min) 200 300 400 500 600 750 800 900 950 1000 Retarder torque (Nm) 100 305 600 895 1211 1575 1600 1650 1650 1640

[0129] Table 5-2

[0130] Transmission shaft speed (r / min) 1100 1250 1400 1500 1600 1700 1900 2100 2300 2500 Retarder speed (r / min) 1100 1250 1400 1500 1600 1700 1900 2100 2300 2500 Retarder torque (Nm) 1600 1575 1550 1450 1325 1264 1131 1023 934 859

[0131] When the vehicle's downhill speed is 5km / h, 8km / h, 10km / h, 15km / h, and 30km / h respectively, the speed n of the front hydraulic retarder is 缓 The calculation formula is: 缓 =n 轴 *g1*g2 can calculate the corresponding retarder speed n 缓 , combined with the retarder data comparison table shown in Table 5-1 and Table 5-2 when the retarder does not increase speed, the pre-hydraulic retarder torque T can be obtained. 缓 ; Combined with the transmission shaft torque T generated by the retarder acting on the transmission shaft 轴 The calculation formula is: T 轴 =T 缓 *g1*g2, and the gearbox speed g2 data in Table 1, the drive shaft torque T can be calculated 轴 ; Due to the drive shaft torque T 轴 The optimal torque range is 3000-6000Nm. By adjusting the gear position of the transmission to adjust the drive shaft torque, the drive shaft torque can reach the optimal torque range and achieve the best braking effect. Table 6 shows the gear position of the transmission and its speed ratio, retarder speed n under different vehicle speed conditions. 缓 , retarder torque T 缓 and the drive shaft torque T 轴 , the retarder speed ratio in Table 6 is 1:1.3, that is, the speed ratio between the front hydraulic retarder and the gearbox is 1:1.3.

[0132] Table 6

[0133]

[0134] Comparing the data of the rear hydraulic retarder in Table 4 with the data of the front hydraulic retarder in Table 6, we can see that the braking torque generated by the rear hydraulic retarder is small and the braking effect is poor when the vehicle speed is below 30km / h. The vehicle speed must be maintained at at least 30km / h, and the retarder torque and the transmission shaft torque can reach about 2422Nm to play a braking role. In actual use, the rear hydraulic retarder is generally used at a speed of V 车 At 30-100km / h, the retarder can play a better braking role, and the maximum torque of the retarder acting on the drive shaft is 3200Nm; and the front hydraulic retarder provided by the present invention can still be adjusted by adjusting the gearbox, using the gear ratio of different gears and the retarder ratio to amplify the retarder speed n when the vehicle speed is lower than 30km / h. 缓 and retarder torque T缓 At the same time, adjust the drive shaft torque T 轴 , so that the transmission shaft torque T 轴 In the optimal torque range (3000-6000Nm), for example: vehicle speed V 车 At 5km / h, by adjusting the gearbox to 6th gear, the drive shaft torque generated by the retarder acting on the drive shaft can reach 4049Nm. The drive shaft torque acts on the wheels through the axle, thereby achieving the best braking effect.

[0135] Therefore, when a heavy-duty vehicle is traveling downhill at a low speed of 5-30 km / h, the rear hydraulic retarder installed at the output end of the gearbox cannot generate braking torque or the generated braking torque is very small and cannot play a good braking role. The hydraulic retarder provided in the present application is connected in parallel to the front end of the gearbox, and the hydraulic retarder is connected in parallel to the input end of the gearbox, breaking through the limitations of the rear hydraulic retarder due to the transmission shaft speed, vehicle load, vehicle speed when going downhill, and alternating changes in the size of the slope. By adjusting the gear position of the gearbox, the adjustment range of the speed and torque of the hydraulic retarder is expanded, and its braking effect is doubled that of the rear hydraulic retarder. Even if the heavy-loaded vehicle is in the speed range of 5-30 km / h, the main brake does not need to be involved. By adjusting the gear position of the gearbox, the transmission shaft torque T formed by the retarder acting on the transmission shaft is reduced. 轴 When in the optimal torque range, the drive shaft torque acts on the wheels through the axle to achieve good braking effect, enabling heavy-loaded vehicles to travel downhill safely and smoothly.

[0136] The above descriptions are merely preferred embodiments of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention shall fall within the scope of the claims of the present invention.

Claims

1. A hydraulic retarder connected in parallel to the front end of a gearbox, comprising a retarder housing, a retarder front cover and a retarder rear cover mounted on both sides of the retarder housing, characterized in that: A working chamber and a gear train transmission mechanism are installed in the retarder housing. The gear train transmission mechanism includes a driving wheel connected to the working chamber, a driving wheel constantly meshed with the driving wheel, and a retarder shaft 1 and a retarder shaft 2 coaxially installed with the driving wheel. The retarder shaft 1 passes through the retarder front cover and is connected to the engine, and the retarder shaft 2 passes through the retarder rear cover and is connected to the gearbox.

2. The hydraulic retarder connected in parallel to the front end of the gearbox according to claim 1, characterized in that: The front end of the retarder shaft is at least partially inserted into the groove provided at the end of the retarder shaft to form coaxial and co-speed rotation; the driving wheel is sleeved on the connecting position of the retarder shaft and the retarder shaft; the external spline at the end of the retarder shaft is meshed with at least a portion of the internal spline of the driving wheel; the retarder shaft is connected to at least a portion of the internal spline of the driving wheel via a connecting gear sleeve; The first shaft of the retarder is connected to the retarder front cover via a first shaft bearing, and a first bearing retaining spring is provided on the outer ring of the first shaft bearing; a first retaining spring groove is provided on the first shaft of the retarder near the inner ring of the first shaft bearing, and a second bearing retaining spring is provided in the first retaining spring groove; The second shaft of the retarder is connected to the retarder rear cover through the second shaft bearing, and a third bearing retaining spring is provided on the outer ring of the second shaft bearing; a second retaining spring groove is provided on the second shaft of the retarder near the inner ring of the second shaft bearing, and a fourth bearing retaining spring is provided in the second retaining spring groove.

3. The hydraulic retarder connected in parallel to the front end of the gearbox according to claim 2, characterized in that: The front end of the retarder shaft is nested in the groove at the end of the retarder shaft through a connecting bearing. The inner ring of the connecting bearing is sleeved with the front end of the retarder shaft, and the outer ring thereof abuts against the inner wall of the groove of the retarder shaft.

4. The hydraulic retarder connected in parallel to the front end of the gearbox according to claim 1, characterized in that: The diameter of the driving wheel is greater than the diameter of the drive wheel, so that the speed ratio of the driving wheel to the drive wheel is greater than 1.

5. The hydraulic retarder connected in parallel to the front end of the gearbox according to claim 1, characterized in that: The diameter of the driving wheel is smaller than that of the drive wheel, so that the speed ratio of the driving wheel to the drive wheel is less than 1.

6. The hydraulic retarder connected in parallel to the front end of the gearbox according to claim 1, characterized in that: The gear train transmission mechanism also includes an idler wheel that is constantly meshed with the driving wheel, the idler wheel and the driving wheel are symmetrically arranged on both sides of the driving wheel, and the center distance between the driving wheel and the idler wheel is equal to the center distance between the driving wheel and the driving wheel; the idler wheel is sleeved on the front end of the retarder third axis that is arranged parallel to the retarder first axis and the retarder second axis, and the rear end of the retarder third axis is fixed to the connecting plate arranged in the retarder housing.

7. The hydraulic retarder connected in parallel to the front end of the gearbox according to claim 1, characterized in that: The oil inlet and oil outlet of the working chamber are respectively installed with a retarder oil inlet pipe and a retarder oil outlet pipe. One end of the retarder oil inlet pipe and the retarder oil outlet pipe pass through the retarder housing and are connected to the oil storage chamber through a flexible oil pipe. The oil outlet of the working chamber is installed with an oil return one-way valve. A temperature sensor is installed in the retarder oil outlet pipe to sense the temperature of the return oil in the retarder oil outlet pipe. The oil flowing out of the working chamber oil outlet is first cooled by the heat exchanger before returning to the oil storage chamber. The working chamber is provided with a retarder exhaust pipe, and the retarder exhaust pipe is connected to the oil-gas separator through an exhaust hose.

8. The hydraulic retarder connected in parallel to the front end of the gearbox according to claim 7, characterized in that: The working chamber includes a working chamber front cover, a working chamber rear cover and an accommodating chamber formed by the working chamber front cover and the working chamber rear cover. A stator, a rotor and a rotor shaft are arranged in the accommodating chamber. The front end of the rotor shaft passes through the working chamber front cover and is coaxially installed with the driving wheel. The rear end of the rotor shaft is connected to a retarder oil pump assembly. The oil pump cover of the retarder oil pump assembly is fixed to the outer side of the working chamber rear cover. An oil inlet hole is opened on the oil pump cover. The oil inlet hole is connected to the oil storage chamber through a lubricating oil inlet pipe. A lubricating oil return pipe is connected between the working chamber front cover and the retarder oil outlet pipe.

9. A torque control method for a hydraulic retarder connected in parallel to a front end of a gearbox according to any one of claims 1 to 8, characterized in that: The steps include: Step ⑴: When the vehicle requires the hydraulic retarder to work, start the hydraulic retarder; Step (2): Calculate the vehicle drive shaft speed according to the vehicle downhill speed; Step (3): Calculating the hydraulic retarder speed based on the vehicle's drive shaft speed, the retarder speed ratio, and the speed ratio of the current gear of the transmission; Step (4): obtaining the corresponding retarder torque from the hydraulic retarder speed, and calculating the transmission shaft torque generated by the hydraulic retarder transmitted to the transmission shaft via the transmission according to the hydraulic retarder torque, the retarder speed ratio, and the speed ratio of the current gear of the transmission; Step (5): Determine whether the drive shaft torque is within the optimal torque range. If not, return to step (3) via step (6); if yes, proceed to step (7); Step 6: Adjust the gear position of the transmission; Step 7: Maintain the current gear position of the transmission; Step ⑻: When the vehicle does not need the hydraulic retarder to work, turn off the hydraulic retarder.

10. The torque control method of the hydraulic retarder connected in parallel to the front end of the gearbox according to claim 9, characterized in that: The calculation formula of the hydraulic retarder speed described in step (3) is as follows: n 缓 =n 轴 *g1*g2; Where n 缓 is the retarder speed, n 轴 is the transmission shaft speed, g1 is the retarder speed ratio, and g2 is the speed ratio of the current gear of the transmission; The calculation formula of the transmission shaft torque described in step (4) is as follows: T 轴 =T 缓 *g1*g2; Where, T 轴 is the transmission shaft torque, T 缓 is the retarder torque, g1 is the retarder speed ratio, and g2 is the speed ratio of the current gear of the transmission.

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