Planetary gear two-gear transmission and working method thereof

Abstract

The invention relates to a planetary gear two-gear transmission and a working method thereof.The planetary gear two-gear transmission comprises a transmission shell, a planetary gear transmission mechanism arranged in the transmission shell, a normally-closed clutch and a first actuator driving the normally-closed clutch, a top disc is arranged on the right side of the normally-closed clutch, and the top disc is in transmission connection with the normally-closed clutch in the axial sliding and rotating direction; the right end of the top disc is slidably connected with a gear ring on the periphery of the planetary gear transmission mechanism, and a brake concave part is arranged on the periphery of the left end of the top disc. A braking device is arranged on the transmission shell and comprises a braking block, the braking block is driven by a second actuator to move in the direction perpendicular to the axis of the transmission to be wedged into the braking concave part, and the first actuator and the second actuator share the same power. According to the invention, the advantage of smooth and rapid power-interruption-free gear shifting of the planetary gear can be better exerted, the phenomenon of'locking 'chip burning caused by simultaneous combination of the two clutches is avoided, and the problem of power interruption caused by simultaneous separation of the two clutches can also be avoided.

Description

Technical Field

[0001] The invention relates to a planetary gear two-speed transmission and a working method thereof. Background Art

[0002] The shifting structure of a traditional planetary gear two-speed transmission is composed of two sets of shifting mechanisms. Both sets of shifting mechanisms are generally wet multi-plate clutches. The two sets of shifting mechanisms are driven by two actuators to shift gears, and the two actuators are provided with hydraulic or pneumatic power by different control devices. The two sets of multi-plate clutches are not only large in size, but also require large power from the driver, which is costly. In addition, the two sets of multi-plate clutches are controlled separately, so there is a problem of simultaneous engagement causing the friction plate to burn, and there is also a problem of simultaneous separation that cannot achieve the purpose of uninterrupted and smooth shifting power. Summary of the invention

[0003] The present invention makes improvements to the problems existing in the above-mentioned prior art, that is, the technical problem to be solved by the present invention is to provide a planetary gear two-speed transmission and a working method thereof.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a planetary gear two-speed transmission, including a transmission housing, a planetary gear transmission mechanism arranged inside the transmission housing, a normally closed clutch, and a first actuator driving the normally closed clutch. A top plate is arranged on the right side of the normally closed clutch, and the top plate is connected to the normally closed clutch in an axial sliding and rotational direction transmission manner. The right end of the top plate is slidably connected to the gear ring on the outer periphery of the planetary gear transmission mechanism, and a braking recess is arranged on the outer periphery of the left end of the top plate; a braking device is arranged on the transmission housing, and the braking device includes a brake block, and the brake block is driven by a second actuator to move in a direction perpendicular to the axis of the transmission and wedge into the braking recess, and the first actuator and the second actuator share the same power.

[0005] Furthermore, the inner end of the brake block is provided with a first inclined surface along the reverse rotation direction of the transmission, the outer periphery of the brake block is provided with a first blocking surface along the reverse rotation direction of the transmission, and the outer periphery of the brake block is provided with a second blocking surface along the forward rotation direction of the transmission; the braking recess is a braking hole, the outer end of the braking hole is provided with a second inclined surface corresponding to the first inclined surface, and the periphery of the brake hole is provided with a third blocking surface corresponding to the first blocking surface and a fourth blocking surface corresponding to the second blocking surface.

[0006] Furthermore, the braking device also includes a brake housing fixedly mounted on the transmission housing, the second actuator is disposed in the brake housing, the second actuator includes a second piston chamber, a second piston disposed in the second piston chamber, and the inner end of the second piston is fixedly connected to the brake block.

[0007] Furthermore, a return cavity is provided at the outer end of the second piston cavity, and the return cavity is connected to the second piston cavity to form a step cavity, and the inner diameter of the return cavity is larger than the inner diameter of the second piston cavity; a return disk is provided at the outer end of the second piston, and the return disk is arranged in the return cavity and cooperates with the gap of the inner wall of the return cavity to facilitate gas flow, and a second return spring is provided between the return disk and the brake housing, and one end of the second return spring abuts against the return disk, and the other end abuts against the step wall of the step cavity.

[0008] Furthermore, a cavity cover is provided at the outer end of the return cavity, and the cavity cover or the brake housing is provided with air inlets and outlets for compressed gas, and one or more anti-rotation pins are provided on the cavity cover; one or more anti-rotation holes are provided on the return disk, and the anti-rotation pins are inserted into the anti-rotation holes; a locally protruding contact surface is provided on the outer end face of the return disk to prevent the return disk from fitting against the cavity cover.

[0009] Furthermore, a plurality of axial spline-shaped elongated protrusions are arranged on the inner periphery of the left side of the top plate, and a plurality of axially concave grooves corresponding to the spline-shaped elongated protrusions are arranged on the right side of the clutch drum of the normally closed clutch. The spline-shaped elongated protrusions penetrate into the axially concave grooves, thereby forming an axial sliding and rotational transmission connection between the top plate and the normally closed clutch; the gear ring is slidably connected to the spline groove on the inner periphery of the right end of the top plate via the splines arranged on its outer periphery.

[0010] Furthermore, the inlet and outlet air paths of the first actuator and the second actuator are connected, and the inlet and outlet air paths of the first actuator and the second actuator are connected and controlled by a solenoid valve.

[0011] Furthermore, a first actuator, a push plate, and a normally closed clutch are sequentially arranged in the transmission housing from left to right, the normally closed clutch includes a clutch drum and a clutch hub, a pressure plate is arranged between the clutch drum and the clutch hub, the pressure plate is axially slidingly connected to the clutch drum and is transmission-connected in the rotational direction, a friction pair is arranged on the right side of the pressure plate, the outer periphery of the outer plate of the friction pair is slidingly connected to the clutch drum through a spline, and the inner plate of the friction pair is slidingly connected to the clutch hub through a spline; the first actuator includes a first piston chamber, a first piston arranged in the first piston chamber, a baffle fixed to the transmission housing is arranged on the right side of the inner end of the first piston, a first return spring is arranged between the baffle and the first piston; a friction plate is arranged between the push plate and the clutch drum, and a plurality of compression springs are arranged between the clutch drum and the pressure plate; a support plate is arranged on the right side of the friction pair, and the support plate is fixedly connected to the clutch drum.

[0012] Furthermore, it also includes an input shaft and an output shaft, the input shaft is fixedly connected to the normally closed clutch hub, and the right side surface of the top plate is rotatably connected to the second shell through a plane bearing; the planetary gear transmission mechanism includes a sun gear, a ring gear and a planet carrier assembly, the planet carrier assembly includes a planet carrier, a planetary gear, a planetary gear shaft and a first bearing located between the planetary gear and the planetary gear shaft, a ring gear is arranged on the outer periphery of the sun gear, and a number of planetary gears are evenly distributed between the sun gear and the ring gear, each planetary gear is meshed with the sun gear and the ring gear through gears, the planetary gear is rotatably connected to the planetary gear shaft through the first bearing, and both ends of the planetary gear shaft are fixedly connected to the planet carrier to form a planetary row; the input shaft is fixedly connected to the sun gear, and the output shaft is fixedly connected to the planet carrier.

[0013] Another technical solution adopted by the present invention is: a working method of a planetary gear two-speed transmission, comprising the following working method: (1) In the initial state: the air inlet of the solenoid valve is closed, the air outlet is in the air-release state, the air pressure in the first piston chamber and the second piston chamber is normal pressure, the brake block in the brake device is retracted into the second piston chamber under the action of the second return spring, the first piston is in the leftmost position under the action of the first return spring, the normally closed clutch is in the engaged state under the action of the compression spring, the sun gear is synchronized with the ring gear through the input shaft, the clutch hub, and the planetary carrier, thereby holding the planetary carrier synchronized. At this time, the transmission is in the direct gear state, that is, the second gear state. The second gear power transmission route is from the input shaft to the normally closed clutch, the ring gear and from the sun gear to the planetary gear, the planetary carrier, and the output shaft. At this time, if the power source of the actuator fails, the vehicle can still limp in the direct gear; (2) When neither the input shaft nor the output shaft rotates: the air inlet of the solenoid valve is open and the air outlet is closed. The air pressure in the first piston chamber and the second piston chamber reaches the designed working pressure. The first piston pushes the clutch drum to the right through the push plate and the friction plate. The clutch drum squeezes the compression spring and then pushes the pressure plate. The pressure plate is supported by the top plate, and the top plate is blocked by the transmission housing through the plane bearing. Therefore, the clutch drum squeezes the compression spring and moves to the right until it reaches the designed position. Correspondingly, the normally closed clutch gradually disengages. At the same time, the second piston of the brake device overcomes the pressure of the second return spring and moves toward the ring gear. At this time, the brake block is inserted into the brake hole or pressed against the left end peripheral side of the top plate. (3) Reversing: At this time, if the input shaft rotates in reverse, it will drive the sun gear to rotate in reverse. According to the movement law of planetary gears, the force direction of the ring gear is opposite to that of the sun gear. At this time, if the brake block is wedged into the brake hole, the first blocking surface of the brake block and the third blocking surface of the brake hole will block each other, so that the top plate is braked, and then the ring gear is braked. If the brake block is not wedged into the brake hole, the ring gear drives the clutch drum and the brake block to rotate relative to each other through the top plate, and the top plate and the brake block slide against each other. Because the pressure of the brake block on the top plate is small, the mutual sliding and grinding on the rotation of the top plate can be ignored. When the top plate rotates to the brake block and wedges into the brake hole, the first blocking surface of the brake block and the third blocking surface of the brake hole block each other, so that the ring gear is braked. According to the movement law of planetary gears, when the ring gear is braked, the planet carrier and the sun gear have the same direction of rotation, that is, the planet carrier rotates forward and drives the output shaft to reverse, and the vehicle reverses at the first gear ratio. (4) First gear forward: When the air pressure in the first piston chamber and the second piston chamber reaches the designed working pressure, if the input shaft rotates forward, the sun gear will be driven to rotate forward. According to the motion law of planetary gears, the force direction of the ring gear is opposite to that of the sun gear. At this time, if the brake block is wedged into the brake hole, the second blocking surface of the brake block and the fourth blocking surface of the brake hole will block each other, so that the ring gear is braked. If the brake block is not wedged into the brake hole, the ring gear drives the clutch drum and the brake block to rotate relative to each other through the top plate, and the top plate and the brake block slide against each other. Since the pressure of the brake block on the top plate is small, the mutual sliding and grinding on the rotation of the top plate can be ignored. When the top plate rotates to the brake block and wedges into the brake hole, the second blocking surface of the brake block and the fourth blocking surface of the brake hole will block each other, so that the ring gear is braked. Then the ring gear is blocked and braked. According to the motion law of planetary gears, when the ring gear is braked, the planet carrier and the sun gear have the same direction of rotation, that is, the planet carrier rotates forward and drives the output shaft to rotate forward, and the vehicle moves forward at the first gear speed ratio. (5) Shifting from the first gear to the second gear: When the vehicle is moving forward in the first gear, the air inlet of the solenoid valve is closed and the air outlet is opened. The pressure in the first piston chamber and the second piston chamber gradually decreases, and the pressure on the clutch drum exerted by the push plate gradually decreases. When the pressure on the clutch drum exerted by the push plate is less than the pressure on the compression spring, the clutch drum moves leftward and drives the support plate to move leftward. The normally closed clutch gradually engages until it is fully engaged. Subsequently, under the action of the first return spring, the first piston moves to the leftmost position. At the same time, as the pressure in the second piston chamber decreases, the brake block gradually moves upward under the action of the second return spring. When the first inclined surface is opposite to the second inclined surface, the clutch drum starts to rotate forward from a stationary state under the action of the friction pair. The force exerted by the second inclined surface on the first inclined surface causes the brake block to move upward, so that the normally closed clutch can rotate relative to the brake block until the brake block is completely away from the top plate. The second piston returns to its initial state under the action of the second return spring. At this time, the normally closed clutch is fully engaged, the ring gear is synchronized with the sun gear, and the sun gear and the ring gear hold the planetary carrier assembly synchronously. The transmission state changes to the second gear state with a speed ratio of 1. (6) Shifting from the second gear to the first gear: In the forward movement of the second gear, the air inlet of the solenoid valve is opened and the air outlet is closed. The pressure in the first piston chamber and the second piston chamber gradually increases. The first piston pushes the clutch drum through the push plate and the friction plate. The clutch drum pushes the compression spring and then pushes the pressure plate. The pressure plate is supported by the top plate, and the top plate is blocked by the transmission housing through the plane bearing. Therefore, the clutch drum compresses the compression spring and moves to the right until it reaches the designed position. Accordingly, the normally closed clutch gradually disengages. At the same time, the second piston of the second actuator overcomes the pressure of the second return spring and moves toward the ring gear. When the brake pad contacts the top plate, the pressure on the brake pad is small, and the friction between the brake pad and the top plate is also small. The top plate is on the clutch drum. The top plate continues to rotate forward under the action of the clutch drum, and when the first inclined surface of the brake block fits with the second inclined surface of the brake hole, the force of the second inclined surface of the brake hole on the first inclined surface of the brake block causes the brake block to retract upward and cannot prevent the top plate from continuing to rotate; when the top plate is stopped and then reversed by the action of the clutch drum, when it is reversed to the point where the brake block is opposite to the brake hole, the brake block is wedged into the brake hole under the action of compressed gas, and the fourth blocking surface of the brake hole is blocked by the second blocking surface of the brake block, so that the top plate is braked, and then the gear ring is braked, and then the brake block continues to move toward the top plate, so that the first blocking surface of the brake block and the third blocking surface of the brake hole block each other, so that the first gear is locked, and then the gear ring cannot rotate in both forward and reverse directions.

[0014] Compared with the prior art, the present invention has the following effects: the present invention is reasonably designed, the normally closed clutch and the brake device share one power, the structure is simple, the volume is small, and it can be realized by simple traditional processing technology, and the cost is low. At the same time, the normally closed clutch and the brake device can be well engaged and separated according to the design requirements, thereby better utilizing the advantages of the planetary gear for smooth and fast shifting without power interruption, avoiding the phenomenon of "locking" and burning plates when the two clutches are engaged at the same time, and also avoiding the problem of power interruption caused by the two clutches being separated at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a schematic diagram of a front cross-sectional structure of an embodiment of the present invention; Figure 2 yes Figure 1 Schematic diagram of the decomposition state; Figure 3 is a schematic diagram of a front cross-sectional structure of a braking device in an embodiment of the present invention; Figure 4 is a schematic diagram of the three-dimensional structure of a piston assembly in an embodiment of the present invention; Figure 5 is a schematic diagram of the three-dimensional structure of the top plate in an embodiment of the present invention; Figure 6 is a partial enlarged view of the top plate in the embodiment of the present invention; Figure 7is a schematic diagram of the three-dimensional structure of a clutch drum in an embodiment of the present invention; Figure 8 yes Figure 1 A local diagram of Figure 1 ; Fig. 9 yes Figure 1 A local diagram of Figure 2 .

[0016] In the figure: 1-transmission housing; 2-planetary gear transmission mechanism; 3-normally closed clutch; 4-first actuator; 5-top plate; 6-gear ring; 7-brake device; 8-brake block; 801-first inclined surface; 802-first blocking surface; 803-second blocking surface; 9-transmission axis; 10-brake hole; 101-second inclined surface; 102-third blocking surface; 103-fourth blocking surface; 11-brake housing; 12-second piston chamber; 13-second piston; 14-return chamber; 15-return plate; 16-piston assembly; 17-second return spring; 18-chamber cover; 19-inlet and outlet; 20-anti-rotation pin; 21-anti-rotation hole; 22-contact surface; 23-spline shaped long convex portion; 24-axially concave groove; 25-two-position three-way solenoid valve; 26-push plate; 27-clutch drum; 28-clutch hub; 29-pressure plate; 30-compression spring; 31-friction pair; 311-outer plate; 312-inner plate; 32-support plate; 34-plane bearing; 35-first piston chamber; 36-first piston; 37-baffle; 38-first return spring; 39-friction plate; 40-input shaft; 41-output shaft; 42-first housing; 43-second housing; 44-sun gear; 45-planet carrier; 46-planet gear; 47-planet gear shaft; 48-first bearing; 49-spline; 50-spline groove matching with the outer plate spline. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] like Figures 1 to 9As shown, a planetary gear two-speed transmission of the present invention is improved on the basis of a dual clutch structure and a transmission using the dual clutch structure disclosed in Chinese Patent Publication No. CN202310233541, using only one clutch and adding a braking device, specifically: comprising a transmission housing 1, a planetary gear transmission mechanism 2 arranged inside the transmission housing 1, a normally closed clutch 3, and a first actuator 4 driving the normally closed clutch 3, a top plate 5 of a cylindrical structure is arranged on the right side of the normally closed clutch 3, the top plate 5 is connected to the normally closed clutch shaft 3 in a sliding and rotating direction, the right end of the top plate 5 is connected to the gear ring 6 on the outer periphery of the planetary gear transmission mechanism in a sliding manner, and a braking recess is arranged on the outer periphery of the left end of the top plate 5; a braking device 7 is arranged on the transmission housing 1, the braking device 7 includes a brake block 8, the brake block 8 is driven by the second actuator to move in a direction perpendicular to the transmission axis 9 and wedge into the braking recess, the first actuator 4 and the second actuator share the same shifting power, and the shifting power is a fluid pressure such as hydraulic pressure or pneumatic pressure, preferably pneumatic pressure.

[0020] In this embodiment, Figure 4 As shown, the brake block 8 is cylindrical, and the movement direction of the brake block is perpendicular to the axis of the transmission. The inner end of the brake block 8 is provided with a first inclined surface 801 inclined outward along the reverse rotation direction of the transmission, and the outer periphery of the brake block 8 is provided with a first blocking surface 802 along the reverse rotation direction of the axis of the transmission. The outer periphery of the brake block 8 is provided with a second blocking surface 803 along the forward rotation direction of the transmission. The first blocking surface and the second blocking surface are oppositely distributed on both sides of the brake block. Figure 6 As shown, the braking concave portion is a braking hole or a braking groove, and the braking concave portion is preferably a braking hole 10, and the outer end of the braking hole 10 is provided with a second inclined surface 101 that is convex and inclined toward the outside, and the second inclined surface 101 corresponds to the first inclined surface 801, and the periphery of the braking hole 10 is provided with a third blocking surface 102 corresponding to the first blocking surface 802, and a fourth blocking surface 103 corresponding to the second blocking surface 803. During operation, when the brake block is wedged into the braking hole, if the top plate is in a reverse rotation (i.e., counterclockwise rotation) state, the second blocking surface of the brake block contacts the fourth blocking surface of the braking hole to block each other, so that the top plate does not rotate; if the top plate is in a forward rotation (i.e., clockwise rotation) state, the first blocking surface of the brake block contacts the third blocking surface of the braking hole to block each other, and the top plate does not rotate.

[0021] In this embodiment, the brake device 7 further includes a brake housing 11 fixedly arranged on the periphery of the transmission housing 1, the second actuator is arranged in the brake housing 11, the second actuator includes a second piston chamber 12, a second piston 13 arranged in the second piston chamber 12, a sealing ring is arranged on the inner periphery of the second piston chamber 12 or the outer periphery of the second piston 13, the inner end of the second piston 13 is fixedly connected to the brake block 8, and the two are integrated together. Preferably, the brake housing is integrated with the transmission housing.

[0022] In this embodiment, a return cavity 14 is provided at the outer end of the second piston cavity 12, and the return cavity 14 is connected with the second piston cavity 12 to form a step cavity, and the inner diameter of the return cavity 14 is larger than the inner diameter of the second piston cavity 12; a return disk 15 is provided at the outer end of the second piston 13, and the return disk 15 is integrated with the second piston assembly 13, so that the brake block 8, the second piston 13 and the return disk 15 form an integral piston assembly 16; the return disk 15 is arranged in the return cavity 14 and cooperates with the inner wall gap of the return cavity 14 to facilitate gas flow, and a second return spring 17 sleeved on the second piston 13 is provided between the return disk 15 and the brake housing 11, and one end of the second return spring 17 abuts against the return disk 15, and the other end abuts against the step wall of the step cavity. Preferably, the second return spring is sleeved at the connection between the return disk and the second piston. Since the thrust of the piston assembly only needs to overcome the elastic force of the second return spring, the friction between the top plate and the brake block is small and can be ignored, and does not affect the relative rotation of the top plate and the brake block.

[0023] In this embodiment, a cavity cover 18 is provided at the outer end of the return cavity 14, and the cavity cover 18 or the brake housing 1 is provided with an air inlet and outlet 19 for compressed gas, and one or more anti-rotation pins 20 are fixedly provided on the cavity cover 18; one or more anti-rotation holes 21 are provided on the return plate 15, and the anti-rotation holes correspond to the positions of the anti-rotation pins, and the anti-rotation pins are inserted into the anti-rotation holes to prevent the second piston from rotating.

[0024] In this embodiment, a locally raised contact surface 22 is provided on one of the surfaces of the cavity cover and the return disk to prevent the cavity cover and the return disk from being adsorbed together and fitting the return disk and the cavity cover. Preferably, a locally raised contact surface 22 is provided on the outer end surface of the return disk 15.

[0025] In this embodiment, assuming that the radial load area of ​​the second piston is S1, the radial load area of ​​the return plate is S2, and the contact area between the second return spring and the return plate is S3, the effective working cross-sectional area of ​​the second piston is S=S1+S3. Without considering the friction resistance, if the stable air pressure of the second piston cavity after ventilation is P, and the elastic force of the second return spring is N, the force on the second piston after stabilization is F=PS-N=P(S1+S3)-N.

[0026] In this embodiment, Figure 5 As shown, a plurality of axial spline-shaped elongated protrusions 23 are arranged on the inner periphery of the left side of the top plate 5, and a plurality of axially concave grooves 24 corresponding to the spline-shaped elongated protrusions 23 are arranged on the right side of the clutch drum of the normally closed clutch 3. The spline-shaped elongated protrusions 23 penetrate into the axially concave grooves 24, thereby forming an axial sliding and rotational transmission connection between the top plate and the normally closed clutch; the gear ring is slidably connected with the spline groove on the inner periphery of the right end of the top plate through the splines arranged on its outer periphery.

[0027] In this embodiment, the inlet and outlet gas paths of the first actuator and the second actuator are connected, and the inlet and outlet gas paths of the first actuator and the second actuator are connected and controlled by a solenoid valve. Preferably, the solenoid valve is a two-position three-way solenoid valve 25.

[0028] In this embodiment, the transmission housing 1 is provided with a first actuator 4, a push plate 26, and a normally closed clutch 3 from left to right. The normally closed clutch 3 includes a clutch drum 27 and a clutch hub 28. A pressure plate 29 is provided between the clutch drum 27 and the clutch hub 28. The pressure plate 29 is located on the right side of the clutch drum 27. The outer periphery of the pressure plate 29 forms an axial sliding connection and a rotational transmission connection with the spline groove in the clutch drum 27 through a spline. A plurality of compression springs 30 are provided between the clutch drum 27 and the pressure plate 29. The two ends of the compression spring 30 respectively abut the clutch drum 27 and the pressure plate 29. A friction pair 31 is arranged on the right side of the pressure plate 29. The friction pair 31 includes a plurality of outer plates 311 and a plurality of inner plates 312. The outer circumference of the outer plate 311 of the friction pair is slidably connected to the clutch drum 27 through a spline. The inner plate 312 of the friction pair is slidably connected to the clutch hub 28 through a spline. A support plate 32 is arranged on the right side of the friction pair. The support plate 32 is fixedly connected to the clutch drum 27. The first actuator 4 includes a first piston chamber 35, a first piston 36 arranged in the first piston chamber 35, a baffle 37 fixed to the transmission housing 1 is arranged on the right side of the inner end of the first piston 36, and a first return spring 38 is arranged between the baffle 37 and the first piston 36. A friction plate 39 is arranged between the push plate 26 and the clutch drum 27. This part of the structure is the same as a dual clutch structure and a transmission using the dual clutch structure disclosed in Chinese Patent Publication No. CN202310233541, and will not be repeated here.

[0029] In this embodiment, an input shaft 40 and an output shaft 41 are also included. The input shaft is fixedly connected to the normally closed clutch hub. The transmission housing 1 includes a first housing 42 set on the input shaft 40 through a bearing and a second housing 43 set on the output shaft 41 through a bearing. The first housing and the second housing are arranged opposite to each other on the left and right. The braking device 7 is arranged on the periphery of the first housing 42. The right side surface of the top plate 5 is rotatably connected to the second housing 43 through a plane bearing 34.

[0030] In this embodiment, the planetary gear transmission mechanism 2 includes a sun gear 44, a ring gear 6 and a planet carrier assembly, the planet carrier assembly includes a planet carrier 45, a planetary gear 46, a planetary gear shaft 47 and a first bearing 48 located between the planetary gear 46 and the planetary gear shaft 47, the outer periphery of the sun gear 44 is provided with a ring gear 6, a plurality of planetary gears 46 are evenly distributed between the sun gear 44 and the ring gear 6, each planetary gear 46 is meshed with the sun gear 44 and the ring gear 6 through gears, the planetary gear is rotatably connected to the planetary gear shaft through the first bearing, and both ends of the planetary gear shaft are fixedly connected to the planet carrier to form a planetary row; the input shaft 40 is fixedly connected to the sun gear 44, and the inner periphery of the clutch hub 28 is fixedly connected to the input shaft 40. The output shaft 41 is fixedly connected to the planet carrier 45. This part of the structure is the same as a dual clutch structure and a transmission using the dual clutch structure disclosed in Chinese Patent Publication No. CN202310233541, and will not be repeated here.

[0031] It should be noted that the structures and working principles of the first actuator, the normally closed clutch, the push plate, the pressure plate, the planetary gear transmission mechanism, etc. are the same as those of a dual-clutch structure and a transmission using the dual-clutch structure disclosed in Chinese Patent Publication No. CN202310233541, and they will not be repeated here. The present invention is based on "a dual-clutch structure and a transmission using the dual-clutch structure disclosed in CN202310233541", and only reduces one clutch and adds a braking device. The remaining structures not disclosed in detail are the same as those in the disclosed patent, and they will not be repeated here.

[0032] The working method of the planetary gear two-speed transmission includes the following working methods: (1) In the initial state: the air inlet of the solenoid valve is closed and the air outlet is in the air-release state. The air pressure in the first piston chamber 35 and the second piston chamber 12 is normal pressure. The brake block 8 in the brake device 7 is retracted into the second piston chamber 12 under the action of the second return spring 17. The first piston 36 is in the leftmost position under the action of the first return spring 38. The normally closed clutch 3 is in the engaged state under the action of the compression spring 30. The sun gear 44 is synchronized with the ring gear 6 through the input shaft 40 and the clutch hub 28 by the normally closed clutch 3, thereby holding the planet carrier 45 synchronized. At this time, the transmission is in the direct gear state, that is, the second gear state. The second gear power transmission route is from the input shaft 40 to the normally closed clutch 3, the ring gear 6 and from the sun gear 44 to the planet gear 46, the planet carrier 45, and the output shaft 41. At this time, if the power source of the actuator fails, the vehicle can still limp in the direct gear. (2) When neither the input shaft 40 nor the output shaft 41 rotates: the air inlet of the solenoid valve is open and the air outlet is closed. The air pressure in the first piston chamber 35 and the second piston chamber 12 reaches the designed working pressure. The first piston 36 pushes the clutch drum 27 to the right through the push plate 26 and the friction plate 39. The clutch drum 27 squeezes the compression spring 30 and then pushes the pressure plate 29. The pressure plate 29 is supported by the top plate 5. The top plate 5 is blocked by the transmission housing 1 through the plane bearing 34. Therefore, the clutch drum 27 squeezes the compression spring 30 and moves to the right until it reaches the designed position. Correspondingly, the normally closed clutch 3 is gradually separated. At the same time, the second piston 13 of the brake device 7 overcomes the pressure of the second return spring 17 and moves toward the ring gear. At this time, the brake block 8 is inserted into the brake hole 10 or is supported on the left end peripheral side of the top plate 5. (3) Reversing: At this time, if the input shaft 40 rotates in reverse, the sun gear 44 will be driven to rotate in reverse. According to the movement law of planetary gears, the force direction of the ring gear 6 is opposite to that of the sun gear. At this time, if the brake block 8 is wedged into the brake hole 10, the first blocking surface 802 of the brake block 8 and the third blocking surface 102 of the brake hole 10 will block each other, so that the top plate 5 is braked, and then the ring gear 6 is braked. If the brake block 8 is not wedged into the brake hole 10, the ring gear 6 drives the clutch drum 27 and the brake block 8 to rotate relative to each other through the top plate 5, and the top plate 5 and the brake block 8 slides and grinds against each other; because the pressure of the brake block 8 on the top plate 5 is small, the mutual sliding and grinding on the rotation of the top plate 5 can be ignored. When the top plate 5 rotates to the point where the brake block is wedged into the brake hole 10, the first blocking surface 802 of the brake block 8 and the third blocking surface 102 of the brake hole 10 block each other, so that the ring gear 6 is braked. According to the movement law of the planetary gear, when the ring gear 6 is braked, the planet carrier 45 and the sun gear 44 have the same direction of rotation, that is, the planet carrier 45 rotates forward and drives the output shaft 41 to rotate reversely, and the vehicle reverses at the first gear ratio; (4) First gear forward: When the air pressure in the first piston chamber 35 and the second piston chamber 12 reaches the designed working pressure, if the input shaft 40 rotates forward, the sun gear 44 is driven to rotate forward. According to the movement law of the planetary gear, the force direction of the ring gear 6 is opposite to that of the sun gear. At this time, if the brake block 8 is wedged into the brake hole 10, the second blocking surface 803 of the brake block 8 and the fourth blocking surface 103 of the brake hole 10 block each other, so that the ring gear 6 is braked. If the brake block 8 is not wedged into the brake hole 10, the ring gear 6 drives the clutch drum 27 and the brake block 8 to rotate relative to each other through the top plate 5, and the top plate 5 is used to rotate the clutch drum 27 ... The disc 5 and the brake block 8 slide against each other. Since the pressure of the brake block 8 on the top disc 5 is relatively small, the mutual sliding friction on the rotation of the top disc 5 can be ignored. When the top disc 5 rotates to the brake block 8 and wedges into the brake hole 10, the second blocking surface 803 of the brake block 8 and the fourth blocking surface 103 of the brake hole 10 block each other so that the ring gear 6 is braked. Then the ring gear 6 is blocked and braked. According to the movement law of the planetary gear, when the ring gear 6 is braked, the planet carrier 45 and the sun gear 44 have the same direction of rotation, that is, the planet carrier 45 rotates forward and drives the output shaft 41 to rotate forward, and the vehicle moves forward at the first gear speed ratio. (5) Shifting from the first gear to the second gear: In the first gear forward state, the solenoid valve air inlet is closed and the air outlet is opened, the pressure in the first piston chamber 35 and the second piston chamber 12 gradually decreases, and the pressure on the clutch drum 27 by the push plate 26 gradually decreases. When the pressure on the clutch drum 27 by the push plate 26 is less than the pressure on the compression spring 30, the clutch drum 27 moves left and drives the support plate 32 to move left, and the normally closed clutch 3 gradually engages until it is fully engaged. Subsequently, under the action of the first return spring 38, the first piston 36 moves to the leftmost position; at the same time, as the pressure in the second piston chamber 12 decreases, the brake block 8 is moved to the leftmost position by the second return spring 17. The first inclined surface 801 and the second inclined surface 101 are opposite to each other, and the clutch drum 27 starts to rotate forward from a stationary state under the action of the friction pair 31. The force of the second inclined surface 101 on the first inclined surface 801 causes the brake block 8 to move upward, so that the normally closed clutch 3 can rotate relative to the brake block 8 until the brake block 8 is completely away from the top plate 5. The second piston 13 returns to the initial state under the action of the second return spring 17. At this time, the normally closed clutch 3 is fully engaged, the ring gear 6 is synchronized with the sun gear 44, and the sun gear 44 and the ring gear 6 hold the planetary carrier assembly synchronously, and the transmission state changes to the second gear state of the speed ratio 1; (6) Shifting from the second gear to the first gear: In the forward movement of the second gear, the air inlet of the solenoid valve is opened and the air outlet is closed. The pressure in the first piston chamber 35 and the second piston chamber 12 gradually increases. The first piston 13 pushes the clutch drum 27 through the push plate 26 and the friction plate 39. The clutch drum 27 pushes the compression spring 30 and then pushes the pressure plate 29. The pressure plate 29 is supported by the top plate 5, and the top plate 5 is blocked by the transmission housing 1 through the plane bearing. Therefore, the clutch 27 compresses the compression spring 30 and moves to the right until it reaches the designed position. Correspondingly, the normally closed clutch 3 is gradually separated; at the same time, the second piston 13 of the second actuator overcomes the pressure of the second return spring 17 and moves toward the ring gear. When the brake block 8 contacts the top plate 5, the pressure on the brake block 8 is small, and the friction between the brake block 8 and the top plate 5 is also small. The top plate 5 continues to move forward under the action of the clutch drum 27. When the top plate 5 is stopped and then reversed by the action of the clutch drum 27, when the brake block 8 is reversed to be opposite to the brake hole 10, the brake block 8 is wedged into the brake hole 10 under the action of the compressed gas, and the fourth blocking surface 103 of the brake hole 10 is blocked by the second blocking surface 803 of the brake block 8, so that the top plate 5 is braked, and then the gear ring 6 is braked, and then the brake block 8 continues to move toward the top plate 5, so that the first blocking surface 802 of the brake block 8 and the third blocking surface 102 of the brake hole 10 block each other, so that the first gear is locked, and then the gear ring 6 cannot rotate in both forward and reverse directions.

[0033] The advantages of the present invention are: (1) Compared with the traditional wet multi-plate clutch used for braking, the brake device has fewer parts and a simpler structure. It can be manufactured using simple traditional processing technology. In addition, the brake device and the normally closed clutch are controlled by only one shifting power, so the size is very small and the cost is low. (2) A shift power control brake device and a normally closed clutch, so that the brake device and the normally closed clutch can be well engaged and disengaged according to the design requirements, so as to better play the advantages of the planetary gear for smooth and fast shifting without power interruption, avoid the phenomenon of "locking" and burning plates when the two clutches are engaged at the same time, and avoid the problem of power interruption when the two clutches are disengaged at the same time; (3) Since the thrust required to push the brake pad is very small, the friction force during the sliding process of the brake pad is very small, the friction energy loss can be ignored, and the wear of the brake pad and the top plate can also be ignored, so the reliability is good and the service life is long; (4) There is no additional friction plate, so the wear debris generated during the braking process is reduced accordingly, which is beneficial to keep the lubricating oil in the transmission clean and reduce faults caused by lubricating oil contamination; (5) There is no additional friction plate, and the inertia during the gear shifting process is reduced, which is more conducive to improving the gear shifting speed and smoothness.

[0034] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except when it is obviously impossible to use an one-piece molding process).

[0035] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the present invention include states or shapes that are approximate, similar, or close to them.

[0036] Any component provided by the present invention may be assembled from a plurality of separate components, or may be a separate component manufactured by an integral forming process.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A planetary gear two-speed transmission, comprising a transmission housing, a planetary gear transmission mechanism arranged inside the transmission housing, a normally closed clutch, and a first actuator driving the normally closed clutch, characterized in that: A top plate is provided on the right side of the normally closed clutch, and the top plate is connected to the normally closed clutch in axial sliding and rotational direction transmission, the right end of the top plate is slidingly connected to the gear ring on the outer periphery of the planetary gear transmission mechanism, and a braking recess is provided on the outer periphery of the left end of the top plate; a braking device is provided on the transmission housing, and the braking device includes a brake block, and the brake block is driven by a second actuator to move in a direction perpendicular to the axis of the transmission and wedge into the braking recess, and the first actuator and the second actuator share the same power.

2. A planetary gear two-speed transmission according to claim 1, characterized in that: The inner end of the brake block is provided with a first inclined surface along the reverse rotation direction of the transmission, the outer periphery of the brake block is provided with a first blocking surface along the reverse rotation direction of the transmission, and the outer periphery of the brake block is provided with a second blocking surface along the forward rotation direction of the transmission; the braking recess is a braking hole, the outer end of the braking hole is provided with a second inclined surface corresponding to the first inclined surface, and the periphery of the brake hole is provided with a third blocking surface corresponding to the first blocking surface and a fourth blocking surface corresponding to the second blocking surface.

3. A planetary gear two-speed transmission according to claim 1, characterized in that: The braking device also includes a brake housing fixedly arranged on the transmission housing, the second actuator is arranged in the brake housing, the second actuator includes a second piston chamber, a second piston arranged in the second piston chamber, and the inner end of the second piston is fixedly connected to the brake block.

4. A planetary gear two-speed transmission according to claim 3, characterized in that: A return cavity is provided at the outer end of the second piston cavity, and the return cavity is connected with the second piston cavity to form a step cavity, and the inner diameter of the return cavity is larger than the inner diameter of the second piston cavity; a return disk is provided at the outer end of the second piston, and the return disk is arranged in the return cavity and cooperates with the inner wall gap of the return cavity to facilitate gas flow, and a second return spring is provided between the return disk and the brake housing, and one end of the second return spring abuts against the return disk, and the other end abuts against the step wall of the step cavity.

5. A planetary gear two-speed transmission according to claim 4, characterized in that: A cavity cover is provided at the outer end of the return cavity, and the cavity cover or the brake housing is provided with an air inlet and outlet for compressed gas, and one or more anti-rotation pins are provided on the cavity cover; one or more anti-rotation holes are provided on the return disk, and the anti-rotation pins are inserted into the anti-rotation holes; a locally protruding contact surface is provided on the outer end face of the return disk to prevent the return disk from fitting against the cavity cover.

6. A planetary gear two-speed transmission according to claim 1, characterized in that: A plurality of axial spline-shaped elongated protrusions are arranged on the inner periphery of the left side of the top plate, and a plurality of axially concave grooves corresponding to the spline-shaped elongated protrusions are arranged on the right side of the clutch drum of the normally closed clutch. The spline-shaped elongated protrusions penetrate into the axially concave grooves, thereby forming an axial sliding and rotational transmission connection between the top plate and the normally closed clutch; the gear ring is slidably connected with the spline groove on the inner periphery of the right end of the top plate through the splines arranged on its outer periphery.

7. A planetary gear two-speed transmission according to claim 1, characterized in that: The inlet and outlet air paths of the first actuator and the second actuator are connected, and the inlet and outlet air paths of the first actuator and the second actuator are connected and controlled by a solenoid valve.

8. The planetary gear two-speed transmission according to claim 1, characterized in that: A first actuator, a push plate, and a normally closed clutch are sequentially arranged in the transmission housing from left to right. The normally closed clutch includes a clutch drum and a clutch hub. A pressure plate is arranged between the clutch drum and the clutch hub. The pressure plate is connected to the clutch drum in an axial sliding manner and in a rotational transmission manner. A friction pair is arranged on the right side of the pressure plate. The outer periphery of the outer plate of the friction pair is connected to the clutch drum in a sliding manner through a spline, and the inner plate of the friction pair is connected to the clutch hub in a sliding manner through a spline. The first actuator includes a first piston chamber and a first piston arranged in the first piston chamber. A baffle fixed to the transmission housing is arranged on the right side of the inner end of the first piston, and a first return spring is arranged between the baffle and the first piston. A friction plate is arranged between the push plate and the clutch drum, and a plurality of compression springs are arranged between the clutch drum and the pressure plate. A support plate is arranged on the right side of the friction pair, and the support plate is fixedly connected to the clutch drum.

9. The planetary gear two-speed transmission according to claim 1, characterized in that: It also includes an input shaft and an output shaft, the input shaft is fixedly connected to the normally closed clutch hub, and the right side surface of the top plate is rotatably connected to the transmission housing through a plane bearing; the planetary gear transmission mechanism includes a sun gear, a ring gear and a planet carrier assembly, the planet carrier assembly includes a planet carrier, a planetary gear, a planetary gear shaft and a first bearing located between the planetary gear and the planetary gear shaft, a ring gear is arranged on the outer periphery of the sun gear, and a number of planetary gears are evenly distributed between the sun gear and the ring gear, each planetary gear is meshed with the sun gear and the ring gear through gears, the planetary gear is rotatably connected to the planetary gear shaft through the first bearing, and both ends of the planetary gear shaft are fixedly connected to the planet carrier to form a planetary row; the input shaft is fixedly connected to the sun gear, and the output shaft is fixedly connected to the planet carrier.

10. A method for operating a planetary gear two-speed transmission, characterized in that: The invention comprises a planetary gear two-speed transmission as claimed in any one of claims 1 to 9, and includes the following working method: (1) In the initial state: the air inlet of the solenoid valve is closed, the air outlet is in the air-release state, the air pressure in the first piston chamber and the second piston chamber is normal pressure, the brake block in the brake device is retracted into the second piston chamber under the action of the second return spring, the first piston is in the leftmost position under the action of the first return spring, the normally closed clutch is in the engaged state under the action of the compression spring, the sun gear is synchronized with the ring gear through the input shaft, the clutch hub, and the planetary carrier, thereby holding the planetary carrier synchronized. At this time, the transmission is in the direct gear state, that is, the second gear state. The second gear power transmission route is from the input shaft to the normally closed clutch, the ring gear and from the sun gear to the planetary gear, the planetary carrier, and the output shaft. At this time, if the power source of the actuator fails, the vehicle can still limp in the direct gear; (2) When neither the input shaft nor the output shaft rotates: the air inlet of the solenoid valve is open and the air outlet is closed. The air pressure in the first piston chamber and the second piston chamber reaches the designed working pressure. The first piston pushes the clutch drum to the right through the push plate and the friction plate. The clutch drum squeezes the compression spring and then pushes the pressure plate. The pressure plate is supported by the top plate, and the top plate is blocked by the transmission housing through the plane bearing. Therefore, the clutch drum squeezes the compression spring and moves to the right until it reaches the designed position. Correspondingly, the normally closed clutch gradually disengages. At the same time, the second piston of the brake device overcomes the pressure of the second return spring and moves toward the ring gear. At this time, the brake block is inserted into the brake hole or pressed against the left end peripheral side of the top plate. (3) Reversing: At this time, if the input shaft rotates in reverse, it will drive the sun gear to rotate in reverse. According to the movement law of planetary gears, the force direction of the ring gear is opposite to that of the sun gear. At this time, if the brake block is wedged into the brake hole, the first blocking surface of the brake block and the third blocking surface of the brake hole will block each other, so that the top plate is braked, and then the ring gear is braked. If the brake block is not wedged into the brake hole, the ring gear drives the clutch drum and the brake block to rotate relative to each other through the top plate, and the top plate and the brake block slide against each other. Because the pressure of the brake block on the top plate is small, the mutual sliding and grinding on the rotation of the top plate can be ignored. When the top plate rotates to the brake block and wedges into the brake hole, the first blocking surface of the brake block and the third blocking surface of the brake hole block each other, so that the ring gear is braked. According to the movement law of planetary gears, when the ring gear is braked, the planet carrier and the sun gear have the same direction of rotation, that is, the planet carrier rotates forward and drives the output shaft to reverse, and the vehicle reverses at the first gear ratio. (4) First gear forward: When the air pressure in the first piston chamber and the second piston chamber reaches the designed working pressure, if the input shaft rotates forward, the sun gear will be driven to rotate forward. According to the motion law of planetary gears, the force direction of the ring gear is opposite to that of the sun gear. At this time, if the brake block is wedged into the brake hole, the second blocking surface of the brake block and the fourth blocking surface of the brake hole will block each other, so that the ring gear is braked. If the brake block is not wedged into the brake hole, the ring gear drives the clutch drum and the brake block to rotate relative to each other through the top plate, and the top plate and the brake block slide against each other. Since the pressure of the brake block on the top plate is small, the mutual sliding and grinding on the rotation of the top plate can be ignored. When the top plate rotates to the brake block and wedges into the brake hole, the second blocking surface of the brake block and the fourth blocking surface of the brake hole will block each other, so that the ring gear is braked. Then the ring gear is blocked and braked. According to the motion law of planetary gears, when the ring gear is braked, the planet carrier and the sun gear have the same direction of rotation, that is, the planet carrier rotates forward and drives the output shaft to rotate forward, and the vehicle moves forward at the first gear speed ratio. (5) Shifting from the first gear to the second gear: When the vehicle is moving forward in the first gear, the air inlet of the solenoid valve is closed and the air outlet is opened. The pressure in the first piston chamber and the second piston chamber gradually decreases, and the pressure on the clutch drum exerted by the push plate gradually decreases. When the pressure on the clutch drum exerted by the push plate is less than the pressure on the compression spring, the clutch drum moves leftward and drives the support plate to move leftward. The normally closed clutch gradually engages until it is fully engaged. Subsequently, under the action of the first return spring, the first piston moves to the leftmost position. At the same time, as the pressure in the second piston chamber decreases, the brake block gradually moves upward under the action of the second return spring. When the first inclined surface is opposite to the second inclined surface, the clutch drum starts to rotate forward from a stationary state under the action of the friction pair. The force exerted by the second inclined surface on the first inclined surface causes the brake block to move upward, so that the normally closed clutch can rotate relative to the brake block until the brake block is completely away from the top plate. The second piston returns to its initial state under the action of the second return spring. At this time, the normally closed clutch is fully engaged, the ring gear is synchronized with the sun gear, and the sun gear and the ring gear hold the planetary carrier assembly synchronously. The transmission state changes to the second gear state with a speed ratio of 1. (6) Shifting from the second gear to the first gear: In the forward movement of the second gear, the air inlet of the solenoid valve is opened and the air outlet is closed. The pressure in the first piston chamber and the second piston chamber gradually increases. The first piston pushes the clutch drum through the push plate and the friction plate. The clutch drum pushes the compression spring and then pushes the pressure plate. The pressure plate is supported by the top plate, and the top plate is blocked by the transmission housing through the plane bearing. Therefore, the clutch drum compresses the compression spring and moves to the right until it reaches the designed position. Accordingly, the normally closed clutch gradually disengages. At the same time, the second piston of the second actuator overcomes the pressure of the second return spring and moves toward the ring gear. When the brake pad contacts the top plate, the pressure on the brake pad is small, and the friction between the brake pad and the top plate is also small. The top plate is on the clutch drum. The top plate continues to rotate forward under the action of the clutch drum, and when the first inclined surface of the brake block fits with the second inclined surface of the brake hole, the force of the second inclined surface of the brake hole on the first inclined surface of the brake block causes the brake block to retract upward and cannot prevent the top plate from continuing to rotate; when the top plate is stopped and then reversed by the action of the clutch drum, when it is reversed to the point where the brake block is opposite to the brake hole, the brake block is wedged into the brake hole under the action of compressed gas, and the fourth blocking surface of the brake hole is blocked by the second blocking surface of the brake block, so that the top plate is braked, and then the gear ring is braked, and then the brake block continues to move toward the top plate, so that the first blocking surface of the brake block and the third blocking surface of the brake hole block each other, so that the first gear is locked, and then the gear ring cannot rotate in both forward and reverse directions.

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