Controllable low-loss hydraulic retarder

Abstract

This invention relates to a controllable, low-loss hydraulic retarder, comprising a housing and a cover, an output shaft, and a fixed wheel, a driven wheel, a first clutch, and a second clutch disposed within the housing. The output shaft passes through the housing and the cover and is connected in series to the vehicle's main drivetrain. The driven wheel is fixedly connected to the output shaft. The first clutch is mounted on the inner wall of the housing and connected to the fixed wheel. The second clutch is mounted on the output shaft and connected to the fixed wheel. Under braking conditions, the engagement of the first clutch and the disengagement of the second clutch keep the fixed wheel stationary relative to the housing. Under non-braking conditions, the disengagement of the first clutch and the engagement of the second clutch cause the fixed wheel to rotate synchronously with the output shaft and the driven wheel. A second control valve is provided on the housing to regulate the pressure and oil volume within the housing. This invention controls the engagement and disengagement of the two clutches to change the motion state of the fixed wheel, thereby minimizing losses under non-braking conditions.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic retarder technology, specifically relating to a controllable, low-loss hydraulic retarder. Background Technology

[0002] Hydraulic retarders are primarily used in heavy-duty trucks or special vehicles for braking. They generate braking force through hydraulic transmission and mainly consist of a driving wheel and a fixed wheel. The driving wheel is a rotating component connected to the vehicle's drivetrain. The fixed wheel is typically fixed to the housing, and the driving and fixed wheels form a circular cavity. When the vehicle is traveling on a long downhill section, the driver activates the brake switch. The hydraulic retarder fills the cavity between the driving and fixed wheels with oil through a hydraulic control valve. The driving wheel rotates, driving the oil, which impacts the fixed wheel. Because the fixed wheel is fixed to the housing, the oil rotates along the blade trajectory of the fixed wheel, impacting the driving wheel again, thus creating a cycle. The oil loses energy during the impact on the fixed wheel, and the fixed wheel exerts a reaction force on the oil, which is the source of the vehicle's braking force.

[0003] After braking ends, the oil inside the chamber is discharged. However, during non-braking conditions, the chamber is filled with air. The rotating impeller drives the air, which impacts the stationary impeller, resulting in considerable power consumption. Some hydraulic retarders reduce power consumption by installing turbulent columns on the stationary impeller to lower the airflow velocity, reducing the power consumption to 3%-4% of the transmitted power, but this is still considered relatively high. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a controllable, low-loss hydraulic retarder, solving the problem of excessive power consumption when the hydraulic retarder is not braking.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a controllable low-loss hydraulic retarder, comprising a fixedly connected housing and housing cover, an output shaft, and a fixed wheel, a moving wheel, a first clutch, and a second clutch disposed within the housing; The output shaft passes through the housing and the housing cover, and is connected in series with the vehicle's main drive train. The fixed wheel is rotatably mounted on the inner wall of the box; The drive wheel is fixedly connected to the output shaft, which is used to connect the vehicle's power. The first clutch is mounted on the inner wall of the housing and connected to the fixed wheel; The second clutch is mounted on the output shaft and connected to the fixed wheel; Under braking conditions, the engagement of the first clutch and the disengagement of the second clutch keep the stationary wheel stationary relative to the housing. In non-braking conditions, the fixed wheel rotates synchronously with the output shaft and the moving wheel by disengaging the first clutch and engaging the second clutch. The housing is equipped with a second control valve, which is used to adjust the pressure and oil volume inside the housing according to the braking conditions.

[0006] Furthermore, both the first clutch and the second clutch are wet clutches.

[0007] Furthermore, the fixed wheel is engaged with the friction plate in the first clutch via a spline connection.

[0008] Furthermore, the fixed wheel is engaged with the friction plate in the second clutch via a spline connection.

[0009] Furthermore, the output shaft is provided with a second clutch lubricating oil inlet and a second clutch pressure oil inlet. The second clutch lubricating oil inlet is used to provide lubricating oil to the second clutch, and the second clutch pressure oil inlet is connected to the piston chamber of the second clutch to provide it with pressure oil.

[0010] Furthermore, the housing is also equipped with a first control valve, which is installed in the lubricating oil inlet line of the second clutch to control the amount of lubricating oil entering the second clutch.

[0011] Furthermore, the housing is also provided with a first clutch pressure oil inlet, which is connected to the piston chamber of the first clutch to provide pressure oil to the piston chamber.

[0012] Furthermore, the output shaft is rotatably supported on the housing and the cover by a first output shaft support bearing and a second output shaft support bearing, respectively. The outer side of the first output shaft support bearing and the second output shaft support bearing is also provided with a skeleton oil seal to achieve sealing between the housing and the output shaft and between the cover and the output shaft.

[0013] Furthermore, both the first support bearing and the second support bearing of the output shaft are tapered roller bearings.

[0014] Furthermore, the fixed wheel is rotatably connected to the inner wall of the box via a fixed wheel support bearing.

[0015] The beneficial effects of this invention are as follows: This invention connects the fixed wheel to the retarder housing and output shaft through two clutches respectively. By controlling the engagement and disengagement of the two clutches, the motion state of the fixed wheel is changed. Thus, under the premise of ensuring normal braking, the fixed wheel and the moving wheel are relatively stationary in non-braking conditions, thereby avoiding the braking torque generated by their relative rotation and minimizing the loss in non-braking conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the internal structure of the hydraulic retarder described in this invention; Figure 2 This is a diagram of the oil passage and valve block of the hydraulic retarder described in this invention; Figure 3 Internal state diagram of the hydraulic retarder of the present invention under braking conditions; Figure 4 Internal state diagram of the hydraulic retarder of the present invention under non-braking conditions; The markings in the diagram are: 1. Housing, 2. Fixed wheel, 3. Moving wheel, 4. Housing cover, 5. Second clutch, 6. Second support bearing of output shaft, 7. First clutch, 8. Fixed wheel support bearing, 9. First support bearing of output shaft, 10. Output shaft, 21. Lubricating oil inlet of second clutch, 22. First control valve, 23. Pressure oil inlet of first clutch, 24. Second control valve, 25. Pressure oil inlet of second clutch. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the embodiments, but this should not be construed as limiting the invention in any way.

[0018] like Figure 1 As shown, the hydraulic retarder of the present invention includes a housing 1, a fixed wheel 2, a moving wheel 3, a housing cover 4, a first clutch 7, a second clutch 5, and an output shaft 10. The housing cover 4 is bolted to the opening at one end of the housing 1 and is positioned at the connection between the housing 1 and the housing cover 4 by a stop, and is sealed between the housing 1 and the housing cover 4 by a sealing ring. The housing 1 houses the fixed wheel 2, the moving wheel 3, the first clutch 7, and the second clutch 5. The two ends of the output shaft 10 are rotatably supported on the housing 1 and the housing cover 4 by corresponding tapered roller bearings, and the tapered roller bearings bear the axial force. The tapered roller bearings include a first output shaft support bearing 9 and a second output shaft support bearing 6, wherein the outer ring of the first output shaft support bearing 9 is mounted on the housing 1, and the inner ring is fixed on the output shaft 10; the outer ring of the second output shaft support bearing 6 is mounted on the housing cover 4, and the inner ring is fixed on the output shaft 10. An oil seal is provided on the outer side of the first support bearing 9 and the second support bearing 6 of the output shaft to prevent oil leakage from the housing 1 or the cover 4 between the housing 1 and the output shaft 10.

[0019] The fixed wheel 2 is rotatably connected to the inner wall of the housing 1 via a fixed wheel support bearing 8, and the moving wheel 3 is fixed to the output shaft 10 by bolts and rotates synchronously with the output shaft 10. The blades of the fixed wheel 2 and the moving wheel 3 form an impeller cavity.

[0020] The first clutch 7 is a wet clutch, installed on the inner wall of the housing 1, and includes a piston, friction plates, steel plates, and a fixed pressure plate. The friction plates are provided with internal splines for meshing with the external splines on the fixed wheel 2. When the first clutch 7 is engaged, the fixed wheel 2 is fixedly connected to the housing 1, and the fixed wheel 2 remains stationary relative to the housing 1.

[0021] The second clutch 5 is a wet clutch, installed on the output shaft 10, and includes a piston, friction plates, steel plates, a fixed pressure plate, a return spring, etc. The friction plates are provided with external splines for meshing with the internal splines on the fixed wheel 2. When the second clutch 5 is engaged, the fixed wheel 2 is fixedly connected to the output shaft 10, so that the fixed wheel 2 and the output shaft 10 rotate synchronously.

[0022] In this embodiment, the hydraulic retarder is connected in series with the vehicle's main drivetrain. Specifically, the output shaft of the hydraulic retarder is connected to the gearbox via a drive shaft, and the output shaft and the drive shaft are on the same straight line.

[0023] The oil passages and valve blocks on the hydraulic retarder are arranged as follows: Figure 2 As shown, there are two oil passages at the center of the output shaft 10. The first oil passage is the lubricating oil inlet 21 of the second clutch, through which lubricating oil enters the second clutch 5, providing cooling and lubrication. The second oil passage is the pressure oil inlet 25 of the second clutch, through which pressure oil enters the piston chamber of the second clutch 5, pushing the piston of the second clutch 5 to press against the friction plates and steel plates, thus engaging the second clutch 5. The housing 1 is provided with a pressure oil inlet 23 of the first clutch, through which pressure oil enters the piston chamber of the first clutch 7, pushing the piston of the first clutch 7 to press against the friction plates and steel plates, thus engaging the first clutch 7. Two control valves are also installed on the housing. The first control valve 22 is installed on the lubricating oil inlet of the second clutch 5 to control the oil flow rate through the lubricating oil inlet 21 of the second clutch. The second control valve 24 is installed on the outer edge of the housing 1 to control the pressure in the hydraulic retarder chamber, adjusting the pressure and oil flow rate in the chamber according to the braking conditions to generate different braking torques.

[0024] The working process of the hydraulic retarder described in this invention can be referred to Figure 3 and Figure 4 As shown in the attached figures, the following explanations will cover both braking and non-braking conditions.

[0025] like Figure 3As shown, under braking conditions, pressurized oil enters the piston chamber of the first clutch 7 through the first clutch pressurized oil inlet 23, pushing the piston to press against the friction plates and steel plates, thus engaging the first clutch 7 and keeping the fixed wheel 2 stationary with the hydraulic retarder housing 1. The second clutch pressurized oil inlet 25 does not supply oil, and the second clutch 5 remains disengaged. The second clutch lubricating oil inlet 21 supplies oil, lubricating the friction plates and steel plates of the second clutch 5. The lubricating oil then enters the impeller chamber formed between the fixed wheel 2 and the moving wheel 3, where it is driven by the rotating moving wheel 3 to impact the blades of the fixed wheel 2, generating braking torque.

[0026] When the vehicle speed is high, the oil pressure in the impeller chamber is high. When the pressure exceeds the pressure set by the second control valve 24, oil will be discharged from the second control valve 24, reducing the amount of oil in the chamber and maintaining the braking torque within the required range. When the vehicle speed decreases and the braking torque decreases, the oil pressure in the impeller chamber decreases, the discharged oil decreases, and the amount of oil in the chamber increases, which can maintain the braking torque at a relatively high level.

[0027] like Figure 4 As shown, in non-braking conditions, after braking ends, pressurized oil is discharged from the piston chamber of the first clutch 7, causing the first clutch 7 to disengage. The fixed wheel 2 will rotate freely due to the impact of the oil driven by the moving wheel 3. Then, pressurized oil enters the piston chamber of the second clutch 5 through the pressurized oil inlet 25 of the second clutch, pushing the piston to press against the friction plate and steel plate. The second clutch 5 engages, causing the fixed wheel 2 and the moving wheel 3 to rotate together with the output shaft 10. Therefore, the fixed wheel 2 and the moving wheel 3 can remain relatively stationary, and the oil in the impeller chamber no longer circulates, thus not generating braking torque and minimizing the loss in non-braking conditions.

[0028] When braking is required again, the second clutch 5 disengages and the first clutch 7 engages, restoring the braking state where the moving wheel 3 rotates and the stationary wheel 2 remains stationary.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the specific implementation of the present invention with reference to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the pending claims.

Claims

1. A controllable, low-loss hydraulic retarder, characterized in that, It includes a fixedly connected housing (1) and housing cover (4), output shaft (10), and a fixed wheel (2), a moving wheel (3), a first clutch (7), and a second clutch (5) disposed in the housing (1); The output shaft (10) passes through the housing (1) and the cover (4) and is connected in series with the main drive chain of the vehicle; The fixed wheel (2) is rotatably mounted on the inner wall of the box (1); The drive wheel (3) is fixedly connected to the output shaft (10), and the output shaft (10) is used to connect the vehicle's power. The first clutch (7) is installed on the inner wall of the housing (1) and connected to the fixed wheel (2); The second clutch (5) is mounted on the output shaft (10) and connected to the fixed wheel (2); Under braking conditions, the fixed wheel (2) is kept stationary relative to the housing (1) by engaging the first clutch (7) and disengaging the second clutch (5); In non-braking conditions, the fixed wheel (2) rotates synchronously with the output shaft (10) and the moving wheel (3) by disengaging the first clutch (7) and engaging the second clutch (5); The housing (1) is equipped with a second control valve (24) for adjusting the pressure and oil volume inside the housing (1) according to the braking conditions.

2. The hydraulic retarder according to claim 1, characterized in that, Both the first clutch (7) and the second clutch (5) are wet clutches.

3. The hydraulic retarder according to claim 2, characterized in that, The fixed wheel (2) is engaged with the friction plate in the first clutch (7) by means of spline connection.

4. The hydraulic retarder according to claim 2, characterized in that, The fixed wheel (2) is engaged with the friction plate in the second clutch (5) by means of spline connection.

5. The hydraulic retarder according to claim 1, characterized in that, The output shaft (10) is provided with a second clutch lubricating oil inlet (21) and a second clutch pressure oil inlet (25). The second clutch lubricating oil inlet (21) is used to provide lubricating oil to the second clutch (5), and the second clutch pressure oil inlet (25) is connected to the piston chamber of the second clutch (5) to provide it with pressure oil.

6. The hydraulic retarder according to claim 5, characterized in that, The housing (1) is also provided with a first control valve (22), which is installed on the lubricating oil inlet line of the second clutch (5) to control the lubricating oil inlet of the second clutch (5).

7. The hydraulic retarder according to claim 1, characterized in that, The housing (1) is also provided with a first clutch pressure oil inlet (23) and connected to the piston chamber of the first clutch (7) to provide pressure oil to the piston chamber.

8. The hydraulic retarder according to claim 7, characterized in that, The output shaft (10) is rotatably supported on the housing (1) and the cover (4) by the first support bearing (9) and the second support bearing (6) of the output shaft, respectively. The outer side of the first support bearing (9) and the second support bearing (6) of the output shaft is also provided with a skeleton oil seal to achieve sealing between the housing (1) and the output shaft (10) and between the cover (4) and the output shaft (10).

9. The hydraulic retarder according to claim 8, characterized in that, Both the first support bearing (9) and the second support bearing (6) of the output shaft are tapered roller bearings.

10. The hydraulic retarder according to claim 1, characterized in that, The fixed wheel (2) is rotatably connected to the inner wall of the box (1) via a fixed wheel support bearing (8).

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