Driving axle assembly and service brake and parking brake integrated mechanism thereof

Abstract

A driving axle assembly and a service brake and parking brake integrated mechanism thereof. The service brake and parking brake integrated mechanism comprises a housing (21), an input shaft (22), an external friction pad (24), an internal friction pad (25), a service brake piston (43) and a parking brake piston (33), wherein the input shaft (22) is rotationally mounted on the housing (21); the internal friction pad (25) and the external friction pad (24) are both sleeved on the input shaft (22), the internal friction pad (25) and the input shaft (22) are slidably connected and circumferentially fixed to each other, the external friction pad (24) and the housing (21) are connected and circumferentially fixed to each other, and the service brake piston (43) and the parking brake piston (33) are slidably mounted on the housing (21); during traveling, the service brake piston (43) can drive the internal friction pad (25) and the external friction pad (24) to abut against each other; and during parking, the parking brake piston (33) performs braking, such that the internal friction pad (25) and the external friction pad (24) abut against each other. In the above solution, both service braking and parking braking act on the same group of friction pads, such that the number of the friction pads used is reduced, the stroke of a brake piston is shorter, braking control is more responsive, and a structure is more compact.

Description

Drive axle assembly and its integrated mechanism for service brake and parking brake Technical Field

[0001] The present invention relates to the field of forklift drive axles, and in particular to a drive axle assembly and an integrated mechanism of service brake and parking brake thereof. Background Art

[0002] With the development of my country's logistics economy, the use of forklifts has become more common, and the requirements for forklift braking systems are becoming increasingly higher. Today's forklift braking systems are generally divided into two categories: wet braking and dry braking. Dry brake shoes have the disadvantage of high wear and tear, and they need to be replaced frequently after a period of use. Therefore, new forklift designs will consider the use of wet braking, which minimizes wear on the friction pads during the braking process and prolongs their service life.

[0003] Patent document CN207313042U discloses a forklift driving and parking integrated wet brake drive axle. In this case, pressurized oil enters the parking brake release oil inlet of the left brake assembly, filling the parking brake release oil chamber with pressurized oil. The parking brake piston drives the connecting plate to move rightward simultaneously until the large end face of the parking brake piston contacts the corresponding end face of the left axle housing. A second axial gap is created between the parking brake piston, the connecting plate, and the service brake piston, and a first gap is created between the fixed ring gear and the first left spacer. At this point, the parking brake is released. The parking brake release oil chamber of the left brake assembly loses pressure. Under the action of a spring, the parking brake piston and the connecting plate move leftward together, simultaneously pushing the service brake piston leftward, compressing the sequentially arranged friction plates and spacers until they contact and compress the fixed ring gear. At this point, the service brake oil chamber is depressurized, achieving parking braking. A second axial gap is created between the parking brake piston, the connecting plate, and the service brake piston, indicating that the parking brake is released. The hydraulic oil from the service brake oil inlet of the left brake assembly enters the service brake oil chamber, pushing the service brake piston to the left, pressing the friction plate and spacer against the fixed ring gear to achieve service braking. Conversely, when the service brake oil chamber loses pressure, the service brake is released.

[0004] In the above-mentioned prior art, the parking function of the drive axle is achieved by the parking brake piston pushing the vehicle brake piston to compress the friction plate and the spacer. This requires the parking brake piston and the service brake piston to be arranged axially, which makes the volume of the drive axle larger. Secondly, when parking, the parking brake piston pushes the vehicle brake piston through the connecting plate, so that the service brake piston pushes the friction plate to complete parking. This method increases the stroke of the piston and reduces the braking effect of the drive axle. Technical issues

[0005] In order to solve the problems of large drive axle volume and low transmission efficiency in the prior art, the purpose of the present invention is to provide a drive axle assembly and an integrated mechanism of service brake and parking brake, which has a smaller volume, a more compact structure and a better braking effect. Technical Solutions

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: an integrated mechanism of service brake and parking brake, comprising a housing, an input shaft, an outer friction plate, an inner friction plate, a parking brake assembly and a service brake assembly; the input shaft is rotatably mounted on the housing, the outer friction plate and the inner friction plate are both sleeved on the output shaft, the outer friction plate is slidably connected to the housing and circumferentially fixed, and the inner friction plate is slidably connected to the input shaft and circumferentially fixed; the service brake assembly comprises a service oil cylinder body, a service brake piston and a return spring for driving the service brake piston to reset; the service oil cylinder body is fixed to the housing, the service brake piston is slidably mounted on the service oil cylinder body, and a service oil chamber is provided between the service brake piston and the service oil cylinder body; the service oil chamber is filled with oil, The service brake piston approaches and pushes the inner friction plate, so that the inner friction plate and the outer friction plate are pressed against each other; when the service oil chamber leaks oil, the return spring pushes the service brake piston away from the inner friction plate, so that the inner friction plate, the outer friction plate and the housing are separated from each other; the parking brake assembly includes a parking cylinder body, a parking brake piston and a parking spring for driving the parking brake piston to reset; the parking cylinder body is fixed to the housing, and the parking brake piston is slidably installed on the service oil cylinder body, and a parking oil chamber is provided between the parking brake piston and the parking cylinder body; when the parking oil chamber is filled with oil, the parking brake piston does not brake, and the inner friction plate and the outer friction plate are separated from each other; when the parking oil chamber leaks oil, the parking spring pushes the parking brake piston to brake, and the inner friction plate and the outer friction plate are pressed against each other.

[0007] Preferably, the input shaft, the inner friction plate, the outer friction plate, the service brake assembly and the parking brake assembly are all installed in a cavity formed between the housing and the end of the motor.

[0008] Preferably, the parking brake piston and the service brake piston are both sleeved on the input shaft, the service brake piston and the parking brake piston are both annular, and the service brake piston is located inside the parking brake piston.

[0009] Preferably, an end plate is further included, which is arranged between the piston and the inner friction plate and is slidably installed in the housing. The parking brake piston and the service brake piston both press the inner friction plate by pushing the end plate.

[0010] Preferably, the system further comprises a plurality of guide pins, which are arranged around the input shaft and pass through the end plate and the outer friction plate.

[0011] Preferably, a separation spring is sleeved on the guide pin, and two ends of the separation spring are respectively against the outer friction plate and the end plate.

[0012] Preferably, a brake hub is sleeved on the input shaft, the brake hub is fixedly connected to the input shaft, the inner friction plate is sleeved on the brake hub, and the inner friction plate and the brake hub are connected via a spline.

[0013] Preferably, the input shaft has a raised step, the second retaining ring, the bearing and the brake hub are sequentially sleeved on the input shaft, the second retaining ring is engaged with the input shaft, the brake hub is splined to the input shaft, and the second retaining ring, the bearing, the brake hub and the step on the input shaft are sequentially restrained.

[0014] A drive axle assembly includes the above-mentioned integrated mechanism of service brake and parking brake.

[0015] Preferably, it also includes a motor, a differential and two sets of reducers, the two sets of integrated mechanisms are respectively installed on both sides of the motor, the power of the motor is transmitted to the input shafts of the two sets of integrated mechanisms through the differential, the integrated mechanism is located between the two sets of reducers, and the reducer is connected to the input shaft of the adjacent integrated mechanism. Beneficial effects

[0016] The above scheme integrates the parking brake structure with the service brake structure, making the structure of the drive axle more compact; in the above scheme, the service brake and the parking brake both act on the same set of friction plates, thus reducing the number of friction plates used; the service brake piston and the parking brake piston can both move independently, and the brake piston has a shorter stroke, the braking control is more sensitive, the drive axle has higher braking accuracy, and the braking effect is better; and the above structure also reduces the drag torque during driving, reduces power loss, and improves transmission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a structural diagram of the drive axle assembly.

[0018] Figure 2 is a second structural diagram of the drive axle assembly.

[0019] FIG3 is a structural diagram 1 of the integrated mechanism.

[0020] FIG4 is a second structural diagram of the integrated mechanism.

[0021] FIG5 is a schematic diagram of the connection structure between the parking brake oil inlet connector and the parking oil chamber.

[0022] FIG6 is a schematic diagram of the connection structure of the service brake oil inlet connector and the exhaust connector with the brake oil chamber.

[0023] Reference numerals: 1, motor; 11, rotating shaft; 12, spline sleeve; 21, housing; 22, input shaft; 23, brake hub; 24, outer friction plate; 25, inner friction plate; 26, end plate; 27, guide pin; 28, release spring; 29, bearing; 20, first retaining ring; 201, second retaining ring; 31, parking oil cylinder body; 311, parking oil inlet; 32, first connecting portion; 33, parking brake piston; 34, first abutting portion; 3 5. Parking oil chamber; 36. Parking spring; 37. Parking brake oil inlet connector; 38. Screw; 41. Service oil cylinder body; 411. Service oil inlet port; 412. Exhaust port; 42. Second connecting part; 43. Service brake piston; 44. Service oil chamber; 45. Return bolt; 46. Return spring; 47. Service brake oil inlet connector; 5. Differential; 6. Reducer; 71. Exhaust connector; 711. Exhaust connector seat; 72. Breather. Best Mode for Carrying Out the Invention

[0024] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 limiting the present invention.

[0026] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise explicitly specified.

[0027] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0029] As shown in Figures 2 to 4, an integrated mechanism for service brake and parking brake includes a housing 21, an input shaft 22, an inner friction plate 25, an outer friction plate 24, a service brake assembly 4, and a parking brake assembly 3. The input shaft 22 is rotatably mounted on the housing 21, and the outer friction plate 24 and the inner friction plate 25 are both sleeved on the input shaft 22. The outer friction plate 24 is slidably connected to the housing 21, and the inner friction plate 25 is slidably connected to the input shaft 22 and is circumferentially fixed.

[0030] As shown in Figures 3 and 4, the service brake assembly 4 includes a service brake piston 43, a service oil cylinder body 41, and a return spring 46 for driving the service brake piston 43 to return to its original position. The service oil cylinder body 41 is fixed to the housing 21, and the service brake piston 43 is slidably mounted on the service oil cylinder body 41. A service oil chamber 44 is provided between the service brake piston 43 and the service oil cylinder body 41. When the service oil chamber 44 is filled with oil, the service brake piston 43 approaches and pushes the inner friction plate 25, so that the inner friction plate 25, the outer friction plate 24 and the housing 21 are tightly pressed against each other. When the service oil chamber 44 is drained of oil, the return spring 46 pushes the service brake piston 43 away from the inner friction plate 25, so that the inner friction plate 25, the outer friction plate 24 and the housing 21 are separated from each other.

[0031] The parking brake assembly 3 includes a parking brake piston 33, a parking oil cylinder body 31 and a parking spring 36 for driving the parking brake piston 33 to reset; the parking oil cylinder body 31 is fixed to the housing 21, and the parking brake piston 33 is slidably installed on the parking oil cylinder body 31, and a parking oil chamber 35 is provided between the parking brake piston 33 and the parking oil cylinder body 31; when the parking oil chamber 35 is filled with oil, the parking brake piston 33 moves away from the inner friction plate 25, so that the inner friction plate 25, the outer friction plate 24 and the housing 21 are separated from each other; when the parking oil chamber 35 is drained, the parking spring 36 pushes the parking brake piston 33, so that the parking brake piston 33 approaches and pushes the inner friction plate 25, so that the inner friction plate 25, the outer friction plate 24 and the housing 21 are pressed against each other.

[0032] In this way, the above scheme integrates the parking brake structure with the service brake structure, thereby slowing down the vehicle's braking structure and making the structure of the drive axle more compact; in the above scheme, service braking and parking braking are achieved through a set of friction plates, which reduces the number of friction plates used, reduces drag torque, reduces power loss, and improves transmission efficiency.

[0033] In this embodiment, an opening is provided at one end of the housing 21 , and the input shaft 22 , the inner friction plate 25 , the outer friction plate 24 , the service brake assembly 4 and the parking brake assembly 3 are all installed in the opening of the housing 21 .

[0034] In this embodiment, the opening of the shell 21 includes a side wall and an annular inner wall, and a first clamping groove is opened on the inner wall. The first clamping ring 20 is clamped at the first clamping groove. The side wall of the shell 21, the parking oil cylinder body 31, the driving oil cylinder body 41 and the first clamping ring 20 are pressed tightly in sequence, and the parking oil cylinder body 31 and the driving oil cylinder body 41 are tightly matched with the inner wall of the shell 21, thereby fixing the parking oil cylinder body 31 and the driving oil cylinder body 41 in the shell 21.

[0035] In this embodiment, the parking brake piston 33 and the service brake piston 43 are both annular, and the input shaft 22 passes through the inner sides of the outer friction plate 24, the inner friction plate 25, the parking brake piston 33, and the service brake piston 43. This arrangement allows the annular pistons to more evenly contact the friction plates, thereby achieving a more stable braking effect.

[0036] In this embodiment, both the parking cylinder 31 and the service cylinder 41 are annular in shape. The input shaft 22 passes through the inside of the parking cylinder 31 and the service cylinder 41. The parking oil chamber 35 between the parking cylinder 31 and the parking brake piston 33 is annular in shape, while the service oil chamber 44 between the service cylinder 41 and the service brake piston 43 is also annular in shape. This arrangement makes the piston movement more uniform and stable, thereby improving the braking effect of the integrated mechanism.

[0037] In order to make the structure of the integrated mechanism more compact, in this embodiment, as shown in Figure 2, a first connecting portion 32 protrudes inwardly on the parking cylinder body 31, and a first abutting portion 34 protrudes on the parking brake piston 33 toward the inner friction plate 25. The first abutting portion 34 is located on the inner side of the first connecting portion 32, and the first abutting portion 34 can extend from the inner side of the first connecting portion 32 and press the inner friction plate 25. The parking cylinder body 31, the first connecting portion 32, the first abutting portion 34 and the parking brake piston 33 enclose a parking oil chamber 35, and a second connecting portion 42 protrudes on the driving cylinder body 41 toward the inner friction plate 25. The second connecting portion 42 is located on the inner side of the parking brake piston 33, and a first accommodating groove is provided on the end surface of the second connecting portion 42 close to the inner friction plate 25. The first accommodating groove is a stepped groove. Part of the driving brake piston 43 is inserted into the first accommodating groove and matches the first accommodating groove. The stepped first accommodating groove and the driving brake piston 43 enclose a driving oil chamber 44. Such an arrangement makes the structure between the service brake assembly 4 and the parking brake assembly 3 more compact, further improves the utilization rate of the space in the housing 21, and further improves the integration rate of the integrated mechanism.

[0038] Further preferably, as shown in Figures 2 and 3, the parking brake piston 33 is located between the first connecting portion 32 and the driving oil cylinder body 41, a second accommodating groove is provided on the parking brake piston 33, and a third accommodating groove is provided on the driving oil cylinder body 41, the parking spring 36 is located between the second accommodating groove and the third accommodating groove, and the two ends of the parking spring 36 are respectively against the inner wall of the second accommodating groove and the inner wall of the third accommodating groove.

[0039] Further preferably, a fourth accommodating groove is defined on the service brake piston 43, with multiple through-holes defined therein. A threaded hole coaxial with the through-hole is defined within the first accommodating groove of the service oil cylinder body 41. A return bolt 45 comprises a head, an intermediate connecting portion, and a threaded portion connected in sequence. A return spring 46 of the service brake assembly 4 is sleeved on the intermediate connecting portion. The threaded portion of the return bolt 45 passes through the through-hole and is threadedly connected to the threaded hole in the service oil cylinder body 41. A portion of the intermediate connecting portion extends into the through-hole of the service brake piston 43. The ends of the return spring 46 respectively abut against the head of the return bolt 45 and the service brake piston 43. Further preferably, there are multiple return bolts 45, and the multiple return bolts 45 are evenly arranged around the input shaft 22.

[0040] To ensure the sealing of the parking oil chamber 35 and the driving oil chamber 44, in this embodiment, a first oil seal is provided between the first connecting portion 32 and the first abutting portion 34 in the parking oil chamber 35, and a second oil seal is provided between the parking brake piston 33 and the parking oil cylinder body 31. In the driving oil chamber 44, a third oil seal is provided between the second abutting portion and the first accommodating groove, and a fourth oil seal is provided between the driving brake piston 43 and the inner wall of the first accommodating groove. Further preferably, the first, second, third, and fourth oil seals are all step seals. Further preferably, the first oil seal is fixed to the first connecting portion 32, the second oil seal is fixed to the parking oil cylinder body 31, and the third and fourth oil seals are both fixed in the accommodating groove. This arrangement ensures the sealing effect of the oil chamber and the stability of the braking force.

[0041] To facilitate the flow of hydraulic fluid into and out of the parking oil chamber 35 and the driving oil chamber 44, in this embodiment, as shown in Figures 1 and 6 , the parking oil cylinder body 31 is provided with a parking oil inlet port 311 communicating with the parking oil chamber 35, and the housing 21 is provided with a parking brake oil inlet connector 37 that plugs into the parking oil inlet port 311. As shown in Figures 1 and 5 , the driving oil cylinder body 41 is provided with a driving oil inlet port 411 communicating with the driving oil chamber 44, and the housing 21 is provided with a driving brake oil inlet connector 47 that plugs into the driving oil inlet port 411. This arrangement facilitates the flow of hydraulic fluid into and out of the hydraulic fluid and the connection of the oil pipes. The brake oil inlet connector also prevents the parking oil cylinder body from rotating relative to the housing 21, thereby ensuring the stability of the oil cylinder position. Furthermore, preferably, the parking brake oil inlet connector 37 is sealed radially and on its end faces with O-rings, while the driving brake oil inlet connector 47 is sealed radially and on its end faces with O-rings. Further preferably, as shown in Figures 1 and 5, the driving oil cylinder body 41 is also provided with an exhaust port 412 connected to the driving oil chamber 44, and the shell 21 is equipped with an exhaust connector seat 711 inserted into the exhaust port 412, and the exhaust connector seat 711 is equipped with an exhaust connector 71.

[0042] To further enhance the stability of the mechanism, in this embodiment, as shown in Figure 4 , the parking cylinder 31 is secured to the housing 21 via axially extending screws 38. This arrangement constrains the parking cylinder 31 radially by the housing 21 and circumferentially by the parking brake oil inlet connector 37. The screws constrain the parking cylinder 31 circumferentially, thereby integrating the housing 21 and the parking cylinder 31 into a single unit and reducing the risk of movement of the driving cylinder 41.

[0043] To enhance braking effectiveness, in this embodiment, a third abutment is formed on the end of the first abutment portion 34 of the parking brake piston 33, and a fourth abutment is formed on the second abutment portion of the service brake piston 43. When the parking brake piston 33 is braking, the end surfaces of the first abutment portion 34 and the third abutment contact tightly against the inner friction plate 25. When the service brake piston 43 is braking, the end surfaces of the second abutment portion and the fourth abutment contact tightly against the inner friction plate 25. This arrangement increases the contact area between the piston and the friction plate, enhancing braking effectiveness.

[0044] More preferably, the fourth abutting portion is located inside the third abutting portion, and both the third abutting portion and the fourth abutting portion are located between the inner friction plate 25 and the second connecting portion 42 of the driving oil cylinder body 41. This arrangement further improves the compactness of the integrated mechanism.

[0045] To make the integrated mechanism more compact, in this embodiment, the inner friction plate 25 is located inside the parking cylinder 31, and the inner friction plate 25 and the parking brake piston 33 are located on either side of the first connecting portion 32. This arrangement improves the connection effect of the integrated mechanism and further enhances the integration of the service brake and parking brake.

[0046] In order to improve the durability of the integrated mechanism, in this embodiment, an end plate 26 that can slide axially along the input shaft 22 is installed between the inner friction plate 25 and the first connecting portion 32 of the parking cylinder body 31. The service brake piston 43 and the parking brake piston 33 push the end plate 26 to press the inner friction plate 25 and the outer friction plate 24, thereby better protecting the brake piston.

[0047] Further preferably, multiple guide pins 27 are fixed within the opening of the housing 21. The guide pins 27 are located inside the parking cylinder body 31. The guide pins 27 are evenly arranged around the input shaft 22 and pass through the end plate 26 and the outer friction plate 24. This arrangement ensures that the outer friction plate 24 and the end plate 26 move along the same path, thereby improving braking stability.

[0048] Further preferably, as shown in Figures 3 and 4 , a release spring 28 is sleeved on the guide pin 27, with its ends respectively abutting against the end plate 26 and the outer friction plate 24. This arrangement, with the release spring 28 between the friction plates, reduces drag torque, minimizes power loss, and improves transmission efficiency.

[0049] More preferably, as shown in Figure 3, a fifth receiving slot is defined within the opening of the housing 21, and a sixth receiving slot is defined on the first connecting portion 32 of the parking cylinder 31. The ends of the guide pin 27 are positioned in the fifth and sixth receiving slots, respectively, and fit snugly into these slots. This arrangement, through the guide pin 27, allows for more precise positioning of the parking cylinder 31 and the housing 21, while also facilitating assembly of the integrated mechanism.

[0050] In this embodiment, as shown in Figure 3, a brake hub 23 is sleeved and fixedly installed on the input shaft 22, and the inner friction plate 25, the outer friction plate 24 and the end plate 26 are all sleeved on the brake hub 23, and the inner friction plate 25 and the brake hub 23 are spline-connected; wherein, the connection method of the brake hub 23 and the input shaft 22 is that a step is raised on the input shaft 22, the second clamping ring 201, the bearing 29 and the brake hub 23 are sleeved on the input shaft 22 in sequence, the second clamping ring 201 is clamped with the input shaft 22, and the brake hub 23 is spline-connected to the input shaft 22, the second clamping ring 201, the inner ring of the bearing 29, the brake hub 23 and the step on the input shaft 22 are limited in sequence, the second clamping ring 201 and a part of the brake hub 23 can extend into the opening of the service brake piston 43, and the outer ring of the bearing 29 is limited by the third clamping ring installed on the housing 21 and the step in the housing. Such an arrangement can prevent the friction plate from working directly on the input shaft 22, thereby preventing damage to the input shaft 22, effectively utilizing the space in the motor housing, and making the structure of the integrated mechanism more compact.

[0051] During the vehicle's travel: the parking oil chamber is filled with oil, the parking brake piston is away from the friction plate and compresses the parking spring, the driving oil chamber is not filled with oil, the return spring pushes the parking brake piston away from the friction plate, the release spring pushes the outer friction plate, the inner friction plate and the end plate are separated from each other, and the input shaft is in a free rotation state;

[0052] When the vehicle brakes while driving, the service oil chamber is filled with oil, and the hydraulic oil pushes the service brake piston to move. The service brake piston moves and compresses the return spring. The service brake piston moves to press the end plate, inner friction plate and outer friction plate together. The movement of the end plate compresses the release spring. The end plate, inner friction plate and outer friction plate squeeze each other and gradually reduce the input shaft speed, completing the braking process of the vehicle while driving;

[0053] When the vehicle is parked, the parking oil chamber is filled with oil, the parking brake piston moves away from the friction plate and compresses the parking spring. The driving oil chamber is not filled with oil, the return spring pushes the parking brake piston away from the friction plate, and the release spring pushes the outer friction plate, the inner friction plate and the end plate to separate from each other, and the input shaft is in a free rotation state;

[0054] When the vehicle is parked, the parking oil chamber is drained, the parking spring pushes the parking brake piston to move, the parking brake piston moves to press the end plate, inner friction plate and outer friction plate, and the end plate moves to compress the separation spring, thereby completing the parking action.

[0055] A drive axle assembly, as shown in Figures 1 and 2, includes the aforementioned integrated mechanism for service and parking brakes, as well as a motor 1, a differential 5, and a speed reducer 6. Two integrated mechanisms are mounted on either side of the motor 1. The motor 1 includes a base and a motor shaft for outputting power, which is drivingly connected to the differential. The differential includes two opposing side gears, one of which is splined to the input shaft of one base mechanism. The other side gear is splined to a rotating shaft, which passes through the motor shaft and is drivingly connected to the input shaft 22 of the other integrated mechanism via a spline sleeve 12. Two speed reducers 6 are mounted on motor 1 bases 21 of the two integrated mechanisms, respectively, and are drivingly connected to the motor 1 via the input shaft 22 of the integrated mechanism. The specific structure of the differential can be found in patent publications such as CN113883252A, CN110145584A, and CN115264023A.

[0056] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0057] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. An integrated mechanism for service brake and parking brake, characterized in that: The invention comprises a housing (21), an input shaft (22), an outer friction plate (24), an inner friction plate (25), a parking brake assembly (3) and a service brake assembly (4); the input shaft (22) is rotatably mounted on the housing (21); the outer friction plate (24) and the inner friction plate (25) are sleeved on the input shaft (22); the outer friction plate (24) is slidably connected to the housing (21) and is circumferentially fixed; the inner friction plate (25) is slidably connected to the input shaft (22) and is circumferentially fixed; the service brake assembly (4) comprises A driving oil cylinder body (41), a driving brake piston (43) and a return spring (46) for driving the driving brake piston (43) to return to its original position; the driving oil cylinder body (41) is fixed to the housing (21), the driving brake piston (43) is slidably mounted on the driving oil cylinder body (41), and a driving oil chamber (44) is provided between the driving brake piston (43) and the driving oil cylinder body (41); the driving oil chamber (44) is filled with oil, and the driving brake piston (43) approaches and pushes the inner friction plate (25), so that the inner friction plate (25) and the outer friction plate (24) are pressed against each other; when the driving oil chamber (44) leaks oil, the return spring (46) pushes the driving brake piston (43) away from the inner friction plate (25), so that the inner friction plate (25), the outer friction plate (24) and the housing (21) are separated from each other; the parking brake assembly (3) includes a parking oil cylinder body (31), a parking brake piston (33) and a parking spring (36) for driving the parking brake piston (33) to return; the parking oil cylinder body (31) is fixed on the housing (21) The parking brake piston (33) is slidably mounted on the driving oil cylinder body (41), and a parking oil chamber (35) is provided between the parking brake piston (33) and the parking oil cylinder body (31); when the parking oil chamber (35) is filled with oil, the parking brake piston (33) does not brake, and the inner friction plate (25) and the outer friction plate (24) are separated from each other; when the parking oil chamber (35) is drained of oil, the parking spring (36) pushes the parking brake piston (33) to brake, and the inner friction plate (25) and the outer friction plate (24) are pressed against each other.

2. The integrated mechanism of service brake and parking brake according to claim 1, characterized in that: The input shaft (22), the inner friction plate (25), the outer friction plate (24), the service brake assembly (4) and the parking brake assembly (3) are all installed in a cavity formed between the housing (21) and the end of the motor.

3. The integrated mechanism of service brake and parking brake according to claim 1, characterized in that: The parking brake piston (33) and the service brake piston (43) are both sleeved on the input shaft (22); the service brake piston (43) and the parking brake piston (33) are both ring-shaped; the service brake piston (43) is located inside the parking brake piston (33).

4. The integrated mechanism of service brake and parking brake according to claim 1, characterized in that: It also includes an end plate (26) disposed between the piston and the inner friction plate (25), the end plate (26) being slidably mounted in the housing (21), and the parking brake piston (33) and the service brake piston (43) both press the inner friction plate (25) by pushing the end plate (26).

5. The integrated mechanism of service brake and parking brake according to claim 4, characterized in that: It also includes a plurality of guide pins (27), which are arranged around the input shaft (22), and the plurality of guide pins (27) pass through the end plate (26) and the outer friction plate (24).

6. The integrated mechanism of service brake and parking brake according to claim 5, characterized in that: A separation spring (28) is sleeved on the guide pin (27), and two ends of the separation spring (28) are respectively against the outer friction plate (24) and the end plate (26).

7. The integrated mechanism of service brake and parking brake according to claim 1, characterized in that: A brake hub (23) is sleeved on the input shaft (22), the brake hub (23) is fixedly connected to the input shaft (22), an inner friction plate (25) is sleeved on the brake hub (23), and the inner friction plate (25) and the brake hub (23) are connected via a spline.

8. The integrated mechanism of service brake and parking brake according to claim 7, characterized in that: The input shaft (22) has a protrusion with a step, the second clamping ring (201), the bearing (29) and the brake hub (23) are sequentially sleeved on the input shaft (22), the second clamping ring (201) is clamped with the input shaft (22), the brake hub (23) is spline-connected with the input shaft (22), and the second clamping ring (201), the bearing (29), the brake hub (23) and the step on the input shaft (22) are sequentially restrained.

9. A drive axle assembly, characterized in that: An integrated mechanism for service brake and parking brake comprising any one of claims 1-8.

10. A drive axle assembly according to claim 9, characterized in that: It also includes a motor (1), a differential (5) and two sets of reducers (6), the two sets of integrated mechanisms are respectively mounted on both sides of the motor (1), the power of the motor (1) is respectively transmitted to the input shafts (22) of the two sets of integrated mechanisms through the differential (5), the integrated mechanism is located between the two sets of reducers (6), and the reducer (6) is drivingly connected to the input shaft (22) of the adjacent integrated mechanism.

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