Positive bidirectional driving and reverse transmission unidirectional locking mechanism

Abstract

The application discloses a positive transmission bidirectional driving reverse transmission unidirectional locking mechanism, which comprises a driving shaft, a driven shaft and a fixed shell, the end face of the driven shaft is provided with a locking groove, the end face of the driving shaft is provided with a combination tooth, the combination tooth is located in the locking groove, the fixed shell is sleeved on the cooperation position of the driving shaft and the driven shaft, and a locking mechanism is arranged in the locking groove; during positive transmission driving shaft positive and reverse rotation and reverse transmission driven shaft positive rotation, the locking mechanism is away from the inner wall of the fixed shell, and the driving shaft and the driven shaft are normally transmission matched; during reverse transmission driven shaft reverse rotation, the locking mechanism is pressed on the inner wall of the fixed shell, so that the driven shaft and the fixed shell are locked. The application realizes the functions of positive transmission bidirectional driving and reverse transmission unidirectional locking through the improvement of the cooperation position of the driving shaft and the driven shaft, and has the advantages of low cost, compact structure, small space occupation and small space layout difficulty.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a forward bidirectional drive and reverse unidirectional locking mechanism. Background Technology

[0002] When a motor vehicle stops or starts on an uphill slope, its own weight generates a downward force parallel to the slope, known as slope resistance. This resistance can cause the vehicle to roll backward along the slope, which is extremely unsafe. For manual transmission vehicles, drivers must coordinate the parking brake, clutch, and accelerator pedal when going uphill. However, this process is cumbersome and difficult to master, especially for novice drivers. This inherent problem is a major drawback of manual transmission (MT) vehicles. Furthermore, due to the inherent characteristics of automatic transmission (AMT) vehicles, hill starts are difficult to control, and this significant defect hinders the widespread adoption of AMT vehicles. For vehicles equipped with automatic transmissions (AT) and continuously variable transmissions (CVT), anti-rollback functionality is also required. Adding anti-rollback functionality to the transmission results in a more complex transmission structure, higher costs, and greater development challenges.

[0003] Based on the above problems, a forward bidirectional drive and reverse unidirectional locking mechanism is needed to achieve unidirectional locking of reverse transmission and bidirectional drive of forward transmission. Summary of the Invention

[0004] In view of this, the present invention provides a forward bidirectional drive and reverse unidirectional locking mechanism. The structure has a solid housing and rolling elements at the joint of the drive shaft and the driven shaft. When the driven shaft rotates in the reverse direction during reverse transmission, the rolling elements press against the inner circle of the fixed housing to lock the driven shaft and the fixed housing. During the forward rotation of the reverse driven shaft and the bidirectional rotation of the forward drive shaft, the rolling elements retract into the groove, so that the drive shaft and the driven shaft can transmit power.

[0005] The present invention relates to a forward bidirectional drive and reverse unidirectional locking mechanism, comprising a drive shaft, a driven shaft, and a fixed housing. The driven shaft has a locking groove on its end face, and the drive shaft has engaging teeth on its end face. The engaging teeth are located within the locking groove to achieve transmission engagement between the drive shaft and the driven shaft. The fixed housing is fitted onto the engagement point between the drive shaft and the driven shaft. A locking mechanism is provided within the locking groove. The locking mechanism has at least two states: one away from the inner wall of the fixed housing and the other pressed against the inner wall of the fixed housing. During forward and reverse rotation of the drive shaft in forward drive and forward rotation of the driven shaft in reverse drive, the locking mechanism moves away from the inner wall of the fixed housing, allowing normal transmission engagement between the drive shaft and the driven shaft. During reverse rotation of the driven shaft in reverse drive, the locking mechanism presses against the inner wall of the fixed housing, causing the driven shaft to lock against the fixed housing.

[0006] Furthermore, the locking mechanism is a rolling element, and the locking groove has a locking slope. During the reverse transmission of the driven shaft, the rolling element rolls upward along the locking slope in the opposite direction of rotation and presses against the inner wall of the fixed housing, causing the driven shaft to lock with the fixed housing.

[0007] Furthermore, the locking groove also has a transmission inclined surface that is angled to the locking inclined surface. The rolling element is located in the groove formed by the locking inclined surface and the transmission inclined surface. The locking inclined surface is located on the forward rotation side of the transmission inclined surface. During the forward rotation of the driven shaft in reverse transmission, the rolling element falls to the bottom of the groove formed by the locking inclined surface and the transmission inclined surface. The slope of the transmission inclined surface is greater than the slope of the locking inclined surface, so that the rolling element does not roll upward along the transmission inclined surface in the opposite direction of rotation during the forward rotation of the driven shaft.

[0008] Furthermore, the locking groove also has a tooth cavity adapted to the engaging tooth. The tooth cavity is located on the forward rotation side of the transmission inclined surface. The engaging tooth is located inside the tooth cavity. The side of the engaging tooth near the rolling element has a pressure inclined surface facing the inside of the drive shaft. When the forward transmission drive shaft reverses or the reverse transmission driven shaft rotates forward, the engaging tooth is close to the rolling element and the pressure inclined surface presses inward against the rolling element, causing the rolling element to move away from the inner wall of the fixed housing.

[0009] Furthermore, an elastic element is provided on the transmission inclined surface, and the elastic element has an elastic force that presses against the rolling element and causes the rolling element to roll upward along the locking inclined surface.

[0010] Furthermore, the engagement end face of the drive shaft is connected to a drive transmission disk, the engagement end face of the driven shaft is connected to a driven transmission disk, the engagement teeth protrude on the drive transmission disk, and the locking groove is formed on the driven transmission disk.

[0011] Furthermore, the fixed housing has a radially inwardly protruding limiting flange at the end radially away from the drive shaft. The limiting flange and the drive transmission disc abut against both sides of the rolling element to form an axial limit on the rolling element.

[0012] Furthermore, the fixed housing is a circular ring structure.

[0013] Furthermore, the bottom of the tooth cavity groove is an arc structure, the inner radial side of the connecting tooth is an inner arc structure adapted to the bottom of the tooth cavity groove, and the outer radial side of the connecting tooth is an outer arc structure adapted to the inner circle of the fixed shell.

[0014] Furthermore, the drive shaft and driven shaft have multiple matching engagement teeth and locking grooves distributed circumferentially at their joint ends.

[0015] The beneficial effects of this invention are:

[0016] This invention achieves the functions of forward transmission bidirectional drive and reverse transmission one-way lock by improving the connection between the drive shaft and the driven shaft. It eliminates the need to improve the gearbox or use multiple one-way clutches to achieve the anti-slip function, greatly simplifying the structure for achieving the anti-slip function. It has low manufacturing and maintenance costs, a compact structure, occupies little space, and is easy to arrange in space.

[0017] When this invention is applied to a vehicle, as the vehicle moves forward, power is transmitted to the drive shaft, which drives the driven shaft to rotate, thereby transmitting power. After the vehicle stops on an uphill slope, it tends to roll backward. At this time, the driven shaft tends to rotate in the opposite direction. The locking mechanism is then driven to approach the inner wall of the fixed housing to lock the driven shaft, thus preventing it from rolling backward and achieving the hill-start assist function. When the vehicle is reversing, the drive shaft reverses, driving the driven shaft to reverse as well, thus achieving power transmission. When the vehicle speed is greater than the engine speed while going downhill, the driven shaft rotates forward and pulls the drive shaft to accelerate. The engine braking function is retained when the vehicle is in gear, and the vehicle can be pushed or towed forward when in neutral. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the exploded structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the assembly structure of the present invention;

[0021] Figure 3 for Figure 2 A schematic diagram of the radial cross-section structure;

[0022] Figure 4 This is a schematic diagram of the installation structure for the elastic element;

[0023] Figure 5 A schematic diagram of a forward-rotating drive shaft structure;

[0024] Figure 6 Schematic diagram of the reverse transmission driven shaft reversal structure;

[0025] Figure 7 A schematic diagram of a forward-drive shaft reversing structure;

[0026] Figure 8 Schematic diagram of a reverse-drive driven shaft rotating forward; Detailed Implementation

[0027] As shown in the figure, the forward bidirectional drive and reverse unidirectional locking mechanism in this embodiment includes a drive shaft 1, a driven shaft 2, and a fixed housing 3. The driven shaft end face has a locking groove 4, and the drive shaft end face has a connecting tooth 5. The connecting tooth is located in the locking groove to realize the transmission cooperation between the drive shaft and the driven shaft. The fixed housing is fitted onto the cooperation point between the drive shaft and the driven shaft. A locking mechanism is provided in the locking groove. The locking mechanism has at least two states: away from the inner wall of the fixed housing and pressed against the inner wall of the fixed housing. During the forward and reverse rotation of the drive shaft in forward drive and the forward rotation of the driven shaft in reverse drive, the locking mechanism is away from the inner wall of the fixed housing, and the drive shaft and the driven shaft are in normal transmission cooperation. During the reverse rotation of the driven shaft in reverse drive, the locking mechanism is pressed against the inner wall of the fixed housing, causing the driven shaft and the fixed housing to lock together.

[0028] Referring to the accompanying drawings, in this embodiment, forward rotation is clockwise rotation, and reverse rotation is counterclockwise rotation. Being on the forward rotation side means being on the clockwise side, and being on the reverse rotation side means being on the counterclockwise side. Forward transmission means that the driving shaft drives the driven shaft to rotate, and reverse transmission means that the driven shaft drags the driving shaft in the opposite direction.

[0029] The locking groove is located on the outer circumference of the driven shaft. Multiple locking grooves can be provided to form a structure similar to an external spline groove. The fixed housing has a circular inner cavity. During actual installation, the fixed housing is fixed to the vehicle frame or other components. When the driven shaft rotates in the reverse direction during reverse transmission, the locking mechanism moves inward toward the fixed housing and presses against the inner wall of the fixed housing, locking the driven shaft and preventing it from rotating. During the forward rotation of the driven shaft during reverse transmission and the forward or reverse rotation of the drive shaft during forward transmission, the locking mechanism is engaged by centrifugal force. The mechanism automatically falls away from the inner circle of the fixed housing, or it can drive the locking mechanism away from the inner circle of the fixed housing through the engagement gear, thus ensuring that the locking mechanism does not interfere with the inner wall of the fixed housing and ensuring normal power transmission between the drive shaft and the driven shaft. This structure achieves the functions of forward transmission, bidirectional drive, and reverse transmission, and one-way locking through the improvement of the engagement point between the drive shaft and the driven shaft. It eliminates the need to improve the gearbox or use multiple one-way clutches to achieve the anti-slip function, greatly simplifying the structure for achieving the anti-slip function. It has low manufacturing and maintenance costs, a compact structure, occupies little space, and has low spatial layout difficulty.

[0030] When this device is applied to a vehicle, as the vehicle moves forward, power is transmitted to the drive shaft, which drives the driven shaft to rotate, thus transmitting power. After the vehicle stops on an uphill slope, it tends to roll backward. At this time, the driven shaft tends to rotate in the opposite direction. The locking mechanism is then driven to approach the inner wall of the fixed housing, locking the driven shaft and preventing it from rolling backward, thus achieving the hill-holding function and assisting in starting on an uphill slope. When the vehicle is reversing, the drive shaft reverses, driving the driven shaft to reverse as well, thus transmitting power. When the vehicle speed is greater than the engine speed while going downhill, the driven shaft rotates forward and pulls the drive shaft to accelerate. When in gear, the engine braking function is retained, and in neutral, the vehicle can be pushed or towed forward.

[0031] In this embodiment, the locking mechanism is a rolling element 6, and the locking groove has a locking inclined surface 4a. During the reverse transmission of the driven shaft, the rolling element rolls upward along the locking inclined surface in the opposite direction of rotation, pressing against the inner wall of the fixed housing to lock the driven shaft and the fixed housing. The rolling element can be a ball or roller, etc. In this embodiment, a roller structure is preferred. By increasing the contact area with the driven shaft and the fixed housing, the locking effect is improved. Figure 3 As shown, the slope of the locking ramp 4a is relatively small. The specific slope is determined based on the actual operating conditions. It is necessary to ensure that during the counterclockwise rotation of the driven shaft in the reverse drive, the rolling element can roll upward along the locking ramp in the opposite direction of rotation. The distance between the uppermost edge of the locking ramp and the inner circle of the fixed housing is less than the diameter of the rolling element, so that the rolling element presses against the inner circle of the housing during the upward rolling process along the locking ramp. In the initial stage of the driven shaft rotation, the inertia of the rolling element can be used to make it roll along the locking ramp to achieve locking. This structure does not require other extra driving components to drive the rolling element to roll. The structure is simple, does not require complex control logic, is easy to manufacture and assemble, and has low manufacturing and maintenance costs.

[0032] In this embodiment, the locking groove also has a transmission inclined surface 4b set at an angle to the locking inclined surface. The rolling element is located in the groove formed by the locking inclined surface and the transmission inclined surface. The locking inclined surface is located on the forward rotation side of the transmission inclined surface. During the forward rotation of the driven shaft in reverse transmission, the rolling element falls to the bottom of the groove formed by the locking inclined surface and the transmission inclined surface. The slope of the transmission inclined surface is greater than the slope of the locking inclined surface, so that the rolling element does not roll upward along the transmission inclined surface against the rotation direction during the forward rotation of the driven shaft. Figure 3 As shown, the transmission ramp and the locking ramp form a V-groove structure. An arc structure can be installed at the bottom of the groove to improve stress concentration. The transmission ramp and the radial direction passing through its upper edge can coincide or approximately coincide at a small angle, resulting in a relatively large slope for the transmission ramp. Figure 5 As shown, when the driving shaft drives the driven shaft to rotate in the forward direction, the rolling element rolls downward along the locking ramp to the bottom of the groove and rests against the transmission ramp. It cannot roll upward along the transmission ramp. At this time, the rolling element automatically falls to the lowest point, away from the inner circle of the fixed housing; combined with Figure 3As shown, the locking ramp forms a large angle with the radial direction passing through its upper edge. The specific angle is determined based on the actual working conditions, ensuring that the slope of the locking ramp is small, combined with... Figure 6 As shown, during the reverse transmission driven shaft reversal process, the rolling element rolls upward from the lowest point along the locking inclined plane against the direction of rotation and presses against the inner circle of the fixed housing to form a lock;

[0033] In this embodiment, the locking groove also has a tooth cavity 4c adapted to the engaging tooth. The tooth cavity is located on the forward rotation side of the transmission inclined surface 4b. The engaging tooth is located inside the tooth cavity. The side of the engaging tooth near the rolling element has a pressure inclined surface 5a facing the inner side of the drive shaft. When the forward transmission drive shaft reverses or the reverse transmission driven shaft rotates forward, the engaging tooth is close to the rolling element and the pressure inclined surface presses inward against the rolling element, causing the rolling element to move away from the inner wall of the fixed housing. Figure 3 As shown, the circumferential length of the tooth cavity 4c is greater than the length of the engaging tooth, allowing the engaging tooth to rotate circumferentially within the cavity. The sidewall of the tooth cavity on the positive transmission side approximately coincides with the radial direction of the driven shaft, providing better support and limitation for the engaging tooth. The slope of the transmission ramp is determined based on actual working conditions, ensuring that when the engaging tooth rotates towards the rolling element side, the transmission ramp presses against the rolling element and has a radially inward component force pressing the rolling element against the bottom of the V-groove. Figure 7 As shown, during the forward drive shaft reversal process, the drive shaft, carrying the engagement teeth, rotates towards the rolling element side. The inclined surface presses against the rolling element, pressing it against the bottom of the V-groove, thus moving the rolling element away from the inner wall of the fixed housing. Figure 8 As shown, during the forward rotation of the driven shaft in reverse transmission, the driven shaft carries the rolling elements towards the side close to the engaging teeth. The inclined surface presses on the rolling elements, pressing them against the bottom of the V-groove, thus moving the rolling elements away from the inner wall of the fixed housing.

[0034] In this embodiment, an elastic element 7 is provided on the transmission inclined surface 4b. The elastic element has an elastic force that presses against the rolling element and causes the rolling element to roll upward along the locking inclined surface. The elastic element can be directly connected to the transmission inclined surface, or a mounting groove can be opened on the transmission inclined surface to install the elastic element in the mounting groove, allowing the elastic element to retract into the mounting groove under pressure. The elastic element can be an elastic structure such as a cylindrical helical spring, a disc spring, or a leaf spring. Figure 4 As shown, in this embodiment, an installation groove is approximately vertically opened on the transmission ramp. A pressure head is slidably installed in the installation groove. The pressure head is connected to the bottom of the installation groove by a cylindrical helical spring. The pressure head presses against the rolling element through the spring, providing auxiliary force to the rolling element during the reverse transmission of the driven shaft, so that the rolling element is pressed against the inner wall of the fixed housing. By adjusting the elastic force of the elastic element, the rolling element tends to rotate towards the transmission ramp side and compress the spring away from the inner wall of the fixed housing during the forward rotation of the driven shaft driven by the drive shaft. The elastic force of the elastic element can be adjusted according to the actual working conditions, which will not be elaborated further.

[0035] In this embodiment, the engagement end face of the drive shaft is connected to a drive transmission disc 8, and the engagement end face of the driven shaft is connected to a driven transmission disc 9. The engagement teeth protrude from the drive transmission disc, and the locking groove is formed on the driven transmission disc. The drive transmission disc and the driven transmission disc can be disc bodies connected to the shaft end by bolts, or they can be integrally formed with the shaft, i.e., disc body structures formed radially outward from the shaft end. In this embodiment, it is preferred that the drive transmission disc and the driven transmission disc be integrally formed with the transmission shaft to improve the transmission torque. The arrangement of the drive transmission disc and the driven transmission disc facilitates the arrangement of the locking groove and the engagement teeth, and facilitates the transmission engagement between the drive shaft and the driven shaft.

[0036] In this embodiment, the fixed housing has a radially inwardly protruding limiting flange 3a at the end radially away from the drive shaft. The limiting flange and the drive transmission disc abut against both sides of the rolling element to axially limit the rolling element. Here, both the axial and radial directions are referenced to the axial and radial directions of the drive shaft or driven shaft. This structure forms a cavity for mounting the rolling element through the limiting flange and the drive transmission disc, facilitating the positioning and installation of the rolling element.

[0037] In this embodiment, the fixed housing is a ring structure. The ring structure of the fixed housing uses less material and has high strength. When the rolling element presses against the inner wall of the fixed housing, the ring structure minimizes the deformation of the fixed housing, providing sufficient support for the rolling element and improving locking performance.

[0038] In this embodiment, the bottom of the tooth cavity groove is an arc structure, the inner radial side of the connecting tooth is an inner arc structure adapted to the bottom of the tooth cavity groove, and the outer radial side of the connecting tooth is an outer arc structure adapted to the inner circle of the fixed housing. Figure 3 As shown, the arc structure of the tooth cavity and the mating tooth facilitates mutual rotation and reduces interference. The inner arc of the mating tooth and the bottom of the tooth cavity groove are in clearance fit, and the outer arc of the mating tooth and the inner circle of the fixed housing are also in clearance fit, which prevents contact wear and improves service life.

[0039] In this embodiment, the drive shaft 1 and driven shaft 2 have multiple matching engagement teeth and locking grooves circumferentially distributed at their joint ends. Referring to the accompanying drawings, the drive transmission disk at the joint end of the drive shaft has four engagement teeth evenly distributed circumferentially, and the driven transmission disk at the joint end of the driven shaft has four locking grooves evenly distributed circumferentially, each matching one of the engagement teeth. The cooperation of multiple engagement teeth and locking grooves improves the torque transmission between the drive shaft and driven shaft and enhances the locking effect. The locking grooves and engagement teeth are preferably centrally symmetrically distributed to improve the force distribution at the joint ends. The number of locking grooves and engagement teeth can be adjusted according to the actual transmission conditions, which will not be elaborated further.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A forward bidirectional drive and reverse unidirectional locking mechanism, characterized in that: The device includes a drive shaft, a driven shaft, and a fixed housing. The driven shaft has a locking groove on its end face, and the drive shaft has engaging teeth on its end face. The engaging teeth are located in the locking groove to achieve transmission between the drive shaft and the driven shaft. The fixed housing is fitted onto the mating area between the drive shaft and the driven shaft. A locking mechanism is provided in the locking groove. The locking mechanism has at least two states: away from the inner wall of the fixed housing and pressed against the inner wall of the fixed housing. During forward and reverse rotation of the drive shaft in forward and reverse rotation of the driven shaft in reverse, the locking mechanism is away from the inner wall of the fixed housing, and the drive shaft and driven shaft are in normal transmission engagement. During reverse rotation of the driven shaft in reverse, the locking mechanism is pressed against the inner wall of the fixed housing, causing the driven shaft and the fixed housing to lock together. The locking mechanism is a rolling element, and the locking groove has a locking slope. During the reverse transmission driven shaft reversal process, the rolling element rolls upward along the locking slope in the opposite direction of rotation and presses against the inner wall of the fixed housing, so that the driven shaft and the fixed housing are locked together. The locking groove also has a transmission inclined surface that is set at an angle to the locking inclined surface. The rolling element is located in the groove formed by the locking inclined surface and the transmission inclined surface. The locking inclined surface is located on the positive rotation side of the transmission inclined surface. During the forward rotation of the driven shaft in the reverse transmission, the rolling element falls to the bottom of the groove formed by the locking inclined surface and the transmission inclined surface. The slope of the transmission inclined surface is greater than the slope of the locking inclined surface, so that the rolling element does not roll upward along the transmission inclined surface against the rotation direction during the forward rotation of the driven shaft. The locking groove also has a tooth cavity that matches the engaging tooth. The tooth cavity is located on the forward rotation side of the transmission inclined plane. The engaging tooth is located inside the tooth cavity. The side of the engaging tooth near the rolling element has a pressure inclined surface facing the inside of the drive shaft. When the forward transmission drive shaft reverses or the reverse transmission driven shaft rotates forward, the engaging tooth is close to the rolling element and the pressure inclined surface presses inward against the rolling element, causing the rolling element to move away from the inner wall of the fixed housing. The fixed housing is a ring structure; the bottom of the tooth cavity is an arc structure, the inner radial side of the connecting tooth is an inner arc structure adapted to the bottom of the tooth cavity, and the outer radial side of the connecting tooth is an outer arc structure adapted to the inner circle of the fixed housing. An elastic element is provided on the transmission inclined surface, and the elastic element has an elastic force that presses against the rolling element and causes the rolling element to roll upward along the locking inclined surface; The drive shaft is connected to a drive transmission disc at its engagement end face, and the driven shaft is connected to a driven transmission disc at its engagement end face. The engagement teeth protrude from the drive transmission disc, and the locking groove is formed on the driven transmission disc.

2. The forward bidirectional drive and reverse unidirectional locking mechanism according to claim 1, characterized in that: The fixed housing has a radially inwardly protruding limiting flange at the end radially away from the drive shaft. The limiting flange and the drive transmission disc abut against both sides of the rolling element to form an axial limit on the rolling element.

3. The forward bidirectional drive and reverse unidirectional locking mechanism according to claim 1, characterized in that: The drive shaft and driven shaft have multiple matching engagement teeth and locking grooves distributed circumferentially at their joint ends.

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