Commercial vehicle brake air compressor

Abstract

This invention provides a commercial vehicle brake air compressor, belonging to the field of air compressor technology. It includes a base with multi-stage vibration damping, a motor connected to the base and coaxially connected to a compression cylinder. The compression cylinder includes a cylinder body, a crankshaft, and a piston assembly. The two ends of the cylinder body form a primary chamber and a secondary chamber, respectively, with a crankshaft cavity formed between the primary and secondary chambers. The crankshaft is rotatably connected to the crankshaft cavity and coaxially connected to the output shaft of the motor. The piston assembly includes a double-ended piston and a connecting rod. The two ends of the double-ended piston are slidably connected to the primary and secondary chambers, respectively. One end of the connecting rod is rotatably connected to the crankshaft, and the other end is rotatably connected to the double-ended piston. The connecting rod, driven by the crankshaft, drives the double-ended piston to reciprocate along its own axial direction. The commercial vehicle brake air compressor provided by this invention improves the overall structural compactness and lightweight performance while ensuring compression efficiency, and has broad market prospects, especially for installation and application in light-duty commercial vehicles.

Description

Technical Field

[0001] This invention belongs to the field of air compressor technology, and specifically relates to a commercial vehicle brake air compressor. Background Technology

[0002] Commercial vehicle braking systems are mostly pneumatic, making air compressors a crucial component. For light-duty commercial vehicles, air compressors not only need to meet compression efficiency design requirements but also need to be miniaturized and lightweight as much as possible.

[0003] Existing automotive air compressors typically employ a multi-cylinder, two-stage compression structure. Each cylinder must be staggered along the crankshaft axis to meet the connection requirements between the piston connecting rod and the crankshaft. As a result, the overall structure lacks compactness and it is difficult to further improve the lightweight performance.

[0004] In the existing technology, some manufacturers have developed air compressors that achieve two-stage compression based on a single-cylinder structure. The principle is to use a stepped cylinder structure, utilizing the large space between the piston end face and the cylinder bottom as the first-stage compression chamber, and the piston and the cylinder circumference of the large-diameter section of the cylinder to form the second-stage compression chamber. Although this structure has obvious advantages in miniaturization and weight reduction compared to the conventional multi-cylinder structure, the volume of the second-stage compression chamber is too small, which greatly limits its compression efficiency. Therefore, it is only suitable for occasions with very small compressed air demand and cannot meet the stable air demand of commercial vehicle braking systems. Summary of the Invention

[0005] This invention provides a commercial vehicle brake air compressor, which aims to improve the overall compactness and lightweight performance while ensuring compression efficiency.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: to provide a commercial vehicle brake air compressor, including a base with multi-stage vibration damping, a motor connected to the base and coaxially connected to the compressor cylinder;

[0007] The compression cylinder includes a cylinder body, a crankshaft, and a piston assembly; the two ends of the cylinder body form a primary chamber and a secondary chamber, respectively, and the crankshaft chamber is formed between the primary chamber and the secondary chamber; the crankshaft is rotatably connected to the crankshaft chamber and coaxially connected to the output shaft of the motor.

[0008] The piston assembly includes a double-ended piston and a connecting rod; the two ends of the double-ended piston are slidably connected to the first-stage chamber and the second-stage chamber, respectively; one end of the connecting rod is rotatably connected to the crankshaft, and the other end is rotatably connected to the double-ended piston; wherein, the connecting rod drives the double-ended piston to reciprocate along its own axis under the drive of the crankshaft.

[0009] In one possible implementation, the dual-head piston includes a connecting frame, a primary piston head, and a secondary piston head; the primary piston head and the secondary piston head are respectively located at both ends of the connecting frame and are respectively connected to the primary chamber and the secondary chamber; the compression cylinder also includes a primary cylinder head and a secondary cylinder head, the primary cylinder head covering the primary chamber and forming a primary compression chamber between the primary piston head and the secondary cylinder head, and the secondary cylinder head covering the secondary chamber and forming a secondary compression chamber between the secondary piston head and the secondary cylinder head.

[0010] In some embodiments, the connecting frame has an internal clearance space and a clearance hole communicating with the internal clearance space, through which the crankshaft extends into the internal clearance space and connects to the connecting rod.

[0011] For example, the first-stage cylinder head is provided with a first-stage exhaust chamber, and the second-stage cylinder head is provided with a second-stage intake chamber and a second-stage exhaust chamber that are isolated from each other; the first-stage exhaust chamber and the second-stage intake chamber are connected by a ventilation passage provided in the cylinder block.

[0012] For example, the end face of the cylinder block facing the motor forms a mating surface, and an annular groove is provided on the mating surface. The cylinder wall inside the cylinder block has a first air passage and a second air passage that communicate with the annular groove. The first air passage communicates with the primary exhaust chamber, and the second air passage communicates with the secondary intake chamber. The end cover of the motor is sealed to the mating surface and covers the annular groove to form a third air passage. The first air passage, the second air passage, and the third air passage together form a ventilation passage.

[0013] In one possible implementation, the side wall of the cylinder block is provided with an intake pipe communicating with the crankshaft cavity, and the secondary cylinder head is provided with an exhaust pipe communicating with the secondary exhaust cavity; the primary piston head is provided with a primary intake valve, and the primary cylinder head is provided with a primary exhaust valve; the secondary cylinder head is provided with a secondary intake valve and a secondary exhaust valve.

[0014] The primary compression chamber receives air from the crankshaft chamber via the primary intake valve and exhausts air into the primary exhaust chamber via the primary exhaust valve; the secondary compression chamber receives air from the secondary intake chamber via the secondary intake valve and exhausts air into the secondary exhaust chamber via the secondary exhaust valve.

[0015] In some embodiments, the commercial vehicle brake air compressor further includes a cooling fan and an air guide shroud; the cooling fan is rotatably connected to the cylinder block and connected to the crankshaft for power take-off, and the air guide shroud is fixed to the cylinder block and forms an air guide cavity between the cylinder block and the cylinder block; the outer periphery of the secondary cylinder head forms at least one ring of ventilation holes based on heat dissipation fins, and the ventilation holes communicate with the air guide cavity.

[0016] For example, a cover is provided on the side of the cylinder block opposite to the motor, and the cooling fan is rotatably connected to the cover via a fan shaft; one end of the fan shaft passes through the crankshaft cavity and is provided with an eccentric block, which is sleeved and fixed to the crankshaft.

[0017] For example, the eccentric block has an eccentric hole, and an elastic sleeve is fitted on the end of the crankshaft facing the cooling fan. The elastic sleeve is embedded in the eccentric hole.

[0018] In some embodiments, the crankshaft includes a counterweight plate and an eccentric shaft; the counterweight plate is coaxially sleeved on the output shaft of the motor, and the eccentric shaft is biased and fixed to the counterweight plate and connected to a connecting rod; wherein, the counterweight plate has a thinning and weight-reducing part along its radial edge near the edge of the eccentric shaft, and the thinning and weight-reducing part is provided with a plurality of weight-adjusting holes.

[0019] The beneficial effects of the commercial vehicle brake air compressor provided by this invention are as follows: Compared with the prior art, the commercial vehicle brake air compressor of this invention adopts a multi-stage vibration damping base, which can reduce vibration transmission and improve operational stability; it is driven by an electric motor and only needs to draw power from the vehicle to operate, which can improve the convenience of installation layout; the crankshaft cavity, primary cavity, and secondary cavity are integrated into the cylinder body and form a structure in which the primary cavity and secondary cavity are oppositely distributed on both sides of the crankshaft cavity. On this basis, the two ends of the double-ended piston are respectively engaged with the primary cavity and the secondary cavity, and the crankshaft driven by the electric motor drives the double-ended piston to reciprocate along its own axis through the connecting rod, thereby realizing single-cylinder two-stage compression. It can not only have the same air compression efficiency as the dual-cylinder two-stage compression commonly used in the prior art, which can meet the demand for stable high-pressure air supply for the commercial vehicle braking system, but also has a clean and compact structure with significant advantages in miniaturization and lightweighting. It has a broad market prospect, especially for installation and application in light truck commercial vehicles. Attached Figure Description

[0020] Figure 1 A three-dimensional structural schematic diagram of a commercial vehicle brake air compressor provided in an embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional structural schematic diagram of a commercial vehicle brake air compressor provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the ventilation duct structure of the primary exhaust chamber and the secondary intake chamber in an embodiment of the present invention;

[0023] Figure 4 This is a three-dimensional structural diagram of the cylinder block used in an embodiment of the present invention;

[0024] Figure 5 An exploded structural diagram of a commercial vehicle brake air compressor (excluding the motor) provided in an embodiment of the present invention;

[0025] Figure 6 This is a cross-sectional view of the connection structure of the crankshaft, piston assembly, and cooling fan in an embodiment of the present invention;

[0026] Figure 7 This is a perspective view of the connection structure of the crankshaft, piston assembly, and cooling fan in an embodiment of the present invention;

[0027] Figure 8 This is an exploded exploded structural diagram of the primary cylinder head used in an embodiment of the present invention;

[0028] Figure 9 This is a schematic diagram of a half-section of the secondary cylinder head used in an embodiment of the present invention;

[0029] Figure 10 This is a three-dimensional structural diagram of the cooling fan used in an embodiment of the present invention;

[0030] Figure 11 This is a three-dimensional structural diagram of the crankshaft used in an embodiment of the present invention;

[0031] Figure 12 For along Figure 2 Schematic diagram of the cross-sectional structure along line AA in the middle.

[0032] In the diagram: 10. Base; 11. Seat plate; 12. First elastic body; 13. Ear plate; 14. Second elastic body; 20. Motor; 30. Compression cylinder; 31. Cylinder body; 311. Primary chamber; 312. Secondary chamber; 3121. Secondary compression chamber; 313. Crankshaft chamber; 314. Mating surface; 3141. Annular groove; 315. Intake pipe; 32. Crankshaft; 321. Elastic sleeve; 322. Counterweight plate; 3221. Thinning and weight reduction section; 3222. Adjustment hole; 323. Eccentric shaft; 33. Piston assembly; 331. Double-ended piston; 3311. Primary piston head; 3312. Secondary piston head; 3313. Connecting frame; 3314. 3315. Internal clearance space; 3316. Clearance hole; 332. Connecting rod; 34. First-stage cylinder head; 341. First-stage exhaust chamber; 342. First-stage exhaust valve; 35. Second-stage cylinder head; 351. Second-stage intake chamber; 352. Second-stage exhaust chamber; 353. Exhaust pipe; 354. Second-stage intake valve; 355. Second-stage exhaust valve; 356. Radiator fins; 357. Ventilation hole; 36. Air passage; 361. First air passage; 362. Second air passage; 363. Third air passage; 37. Case cover; 40. Radiator fan; 41. Fan shaft; 411. Eccentric block; 4111. Eccentric hole; 50. Air guide shroud; 500. Air guide chamber. Detailed Implementation

[0033] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0034] It should be noted that when an element is referred to as being "set on" or "connected to" another element, it can be directly on or indirectly on the other element. It should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" or "several" means two or more, unless otherwise explicitly specified.

[0035] Please refer to the following: Figures 1 to 12 The commercial vehicle brake air compressor provided by the present invention will now be described. The commercial vehicle brake air compressor includes a base 10 with multi-stage vibration damping, a motor 20 connected to the base 10 and coaxially connected, and a compression cylinder 30. The compression cylinder 30 includes a cylinder body 31, a crankshaft 32, and a piston assembly 33. The two ends of the cylinder body 31 respectively form a primary chamber 311 and a secondary chamber 312, and a crankshaft chamber 313 is formed between the primary chamber 311 and the secondary chamber 312. The crankshaft 32 is rotatably connected to the crankshaft chamber 313 and coaxially connected to the output shaft of the motor 20. The piston assembly 33 includes a double-ended piston 331 and a connecting rod 332. The two ends of the double-ended piston 331 are slidably connected to the primary chamber 311 and the secondary chamber 312 respectively. One end of the connecting rod 332 is rotatably connected to the crankshaft 32, and the other end is rotatably connected to the double-ended piston 331. The connecting rod 332 drives the double-ended piston 331 to reciprocate along its own axial direction under the drive of the crankshaft 32.

[0036] It should be noted that in this embodiment, the primary cavity 311, the secondary cavity 312, and the crankshaft cavity 313 together form the internal space of the cylinder block 31. Since the crankshaft 32 drives the double-ended piston 331 to reciprocate through the connecting rod 332, its stroke in the primary cavity 311 and the secondary cavity 312 is equal. As the air volume decreases with compression and pressure increase, the diameter of the primary cavity 311 is larger than the diameter of the secondary cavity 312.

[0037] In this embodiment, the primary cavity 311 and the secondary cavity 312 can be symmetrically distributed on the upper and lower sides of the crankshaft cavity 313, or symmetrically distributed on the left and right sides of the crankshaft cavity 313, or they can be tilted opposite each other. Considering the vibration problem caused by the double-ended piston 331 compressing air, it is preferable to use the upper and lower opposite arrangement of the primary cavity 311 and the secondary cavity 312. It is even more preferable to have the primary cavity 311 at the bottom and the secondary cavity 312 at the top to reduce the overall installation space occupied. Also, considering that the heat generated by the secondary compression is relatively large, the secondary cavity 312 at the top is conducive to obtaining more sufficient air circulation space around it, which is beneficial to the air cooling heat dissipation of the secondary cavity 312.

[0038] The operating principle of the commercial vehicle brake air compressor provided in this embodiment is as follows: the output shaft of the motor 20 drives the crankshaft 32 to rotate, and the crankshaft 32 drives the connecting rod 332 to make a swaying motion, which drives the two ends of the double-ended piston 331 to move up and down in the first-stage chamber 311 and the second-stage chamber 312 respectively, thereby realizing the continuous alternation of the first-stage compression process and the second-stage compression process to obtain high-pressure air.

[0039] Compared with the prior art, the commercial vehicle brake air compressor provided in this embodiment adopts a multi-stage vibration damping base 10, which can reduce vibration transmission and improve operational stability. Driven by a motor 20, it only needs to draw power from the vehicle to operate, which improves the convenience of installation layout. The crankshaft cavity 313, the primary cavity 311, and the secondary cavity 312 are integrated into the cylinder block 31, forming a structure where the primary cavity 311 and the secondary cavity 312 are oppositely distributed on both sides of the crankshaft cavity 313. Based on this, the two ends of the double-ended piston 331 are respectively engaged with the primary cavity 311 and the secondary cavity 312. The crankshaft 32 driven by the motor 20 drives the double-ended piston 331 to reciprocate along its own axis via the connecting rod 332, thereby achieving single-cylinder two-stage compression. This not only has the same air compression efficiency as the commonly used double-cylinder two-stage compression in the prior art, meeting the demand for stable high-pressure air supply to the commercial vehicle braking system, but also has a clean and compact structure with significant advantages in miniaturization and lightweighting. It has a broad market prospect, especially for installation and application in light truck commercial vehicles.

[0040] Specifically, such as Figure 1 As shown, the multi-stage vibration damping base 10 includes two base plates 11. Each base plate 11 has a first elastic body 12 on its top surface at both ends. Each first elastic body 12 is connected to an ear plate 13. The ear plate 13 at one end of the base plate 11 is fixedly connected to the side wall of the motor 20, and the ear plate 13 at the other end of the base plate 11 is fixedly connected to the cylinder 31. Each base plate 11 has a second elastic body 14 on its bottom surface at both ends. Each second elastic body 14 is used to fix the base plate 11 to the installation position on the vehicle.

[0041] By using the first elastic body 12 and the second elastic body 14 to form a two-stage vibration reduction structure, the vibration transmission between the vehicle and the air compressor can be reduced. This not only prevents the vehicle vibration during driving from being directly transmitted to the motor 20 and the compressor cylinder 30, thus affecting the operational stability, but also prevents the vibration of the compressor cylinder 30 during the compressed air work process from being directly transmitted to the vehicle, thus affecting the vehicle's NVH performance.

[0042] In some embodiments, see Figure 2 , Figures 5 to 7 The dual-head piston 331 includes a connecting frame 3313, a first-stage piston head 3311, and a second-stage piston head 3312. The first-stage piston head 3311 and the second-stage piston head 3312 are respectively located at both ends of the connecting frame 3313 and are respectively connected to the first-stage chamber 311 and the second-stage chamber 312. The compression cylinder 30 also includes a first-stage cylinder head 34 and a second-stage cylinder head 35. The first-stage cylinder head 34 covers the first-stage chamber 311 and forms a first-stage compression chamber between it and the first-stage piston head 3311 (the first-stage compression chamber is in the exhaust state in the figure and is therefore not shown). The second-stage cylinder head 35 covers the second-stage chamber 312 and forms a second-stage compression chamber 3121 between it and the second-stage piston head 3312.

[0043] The primary chamber 311 and the secondary chamber 312 at both ends of the cylinder block 31 are open and sealed by the primary cylinder head 34 and the secondary cylinder head 35 fixed at both ends. This forms a primary compression chamber between the primary piston head 3311 extending into the primary chamber 311 and the primary cylinder head 34, and a secondary compression chamber 3121 between the secondary piston head 3312 extending into the secondary chamber 312 and the secondary cylinder head 35. In this way, the surface of the chamber walls of the primary chamber 311 and the secondary chamber 312 can be easily processed during the machining of the cylinder block 31, thereby reducing the machining difficulty and also helping to reduce the weight of the cylinder block 31.

[0044] A double-headed piston 331 is formed by connecting the first-stage piston head 3311 and the second-stage piston head 3312 through the connecting frame 3313. This allows for weight reduction of the overall structure as much as possible by opening holes or slots in the connecting frame 3313 while ensuring the structural strength of the connecting frame 3313.

[0045] Specifically, the first-stage piston head 3311 and the second-stage piston head 3312 can be fixed to the connecting frame 3313 by fasteners such as bolts, or the two can be integrally machined into the connecting frame 3313. Of course, in order to reduce the processing difficulty, a split structure connected by fasteners can be preferred.

[0046] As an optional embodiment of the aforementioned connecting bracket 3313, please refer to Figure 6The connecting frame 3313 has an internal clearance space 3315 and a clearance hole 3316 communicating with the internal clearance space 3315. The crankshaft 32 passes through the clearance hole 3316, extends into the internal clearance space 3315, and connects to the connecting rod 332.

[0047] An internal clearance hole 3316 is provided inside the connecting bracket 3313 to accommodate the connecting rod 332. Simultaneously, the internal clearance space 3315 prevents interference between the connecting rod 332 and the connecting bracket 3313 during the rocking motion driven by the crankshaft 32. Based on this, the crankshaft 32 can be connected to the connecting rod 332 by passing through the clearance hole 3316 and extending into the internal clearance space 3315. The diameter of the clearance hole 3316 should be larger than the rotation diameter of the crankshaft 32 to avoid motion interference. Utilizing the internal clearance space 3315 and clearance hole 3316 of the connecting bracket 3313 not only allows for the installation of the connecting rod 332 inside the connecting component, thus saving space and improving structural compactness, but also contributes to weight reduction and improves lightweight performance.

[0048] Specifically, such as Figure 6 As shown, the connecting frame 3313 includes two connecting plates symmetrically distributed with respect to the first-stage piston head 3311 and the second-stage piston head 3312, forming the aforementioned clearance space between the two connecting plates. Both connecting plates are provided with the aforementioned clearance holes 3316. Furthermore, the two connecting plates are provided with a plurality of weight-reducing grooves and / or weight-reducing holes, which helps to improve the lightweight performance.

[0049] It should be noted that in this embodiment, please refer to... Figure 2 and Figure 3 The first-stage cylinder head 34 is provided with a first-stage exhaust chamber 341, and the second-stage cylinder head 35 is provided with a mutually isolated second-stage intake chamber 351 and a second-stage exhaust chamber 352; the first-stage exhaust chamber 341 and the second-stage intake chamber 351 are connected by a ventilation passage 36 provided in the cylinder block 31.

[0050] After being compressed in the primary compression chamber, the air enters the primary exhaust chamber 341 and is then discharged into the secondary intake chamber 351 through the vent 36. The secondary intake chamber 351 draws air into the secondary compression chamber 3121, and after being compressed to the target pressure in the secondary compression chamber 3121, it enters the secondary exhaust chamber 352. This completes the two-stage compression process to obtain high-pressure air.

[0051] Here, the primary exhaust chamber 341 and the secondary intake chamber 351 are connected by a ventilation channel 36 built into the cylinder block 31. On the one hand, this can save the space occupied by external pipelines and improve the overall structural compactness. On the other hand, it not only reduces the weight of external pipelines, but also further reduces the weight of the cylinder block 31 by setting the ventilation channel 36, thus helping to achieve the lightweighting of the cylinder block 31.

[0052] As one specific embodiment of the aforementioned ventilation duct 36, please refer to Figure 2 and Figure 3 The end face of the cylinder 31 facing the motor 20 forms a mating surface 314. The mating surface 314 is provided with an annular groove 3141. The cylinder wall of the cylinder 31 is provided with a first air passage 361 and a second air passage 362 that communicate with the annular groove 3141. The first air passage 361 communicates with the first-stage exhaust chamber 341, and the second air passage 362 communicates with the second-stage intake chamber 351. The end cover of the motor 20 is sealed and connected to the mating surface 314 and covers the annular groove 3141 to form a third air passage 363. The first air passage 361, the second air passage 362, and the third air passage 363 together form a ventilation passage 36.

[0053] The cylinder block 31 can be equipped with detachable covers 37 at both ends along the output shaft direction of the motor 20, which facilitates the precision machining of the internal structure of the cylinder block 31, thereby reducing the machining difficulty and cost. The cover 37 near the motor 20 mates with the end cover of the motor 20 and uses a concave-convex stop fit to ensure assembly coaxiality. In this case, the surface of the cover 37 facing the motor 20 is the aforementioned mating surface 314. By forming an annular groove 3141 around the output shaft of the motor 20 on the mating surface 314, the end cover of the motor 20 is sealed to the mating surface 314, thus forming a closed third air passage 363. Based on this, the first air passage 361 connecting the primary exhaust chamber 341 and the annular groove 3141 and the second air passage 362 connecting the secondary intake chamber 351 and the annular groove 3141, together with the third air passage 363, can construct an air passage 36 that connects the primary exhaust chamber 341 and the secondary intake chamber 351. The structure is simple and easy to manufacture.

[0054] It is important to understand that, in combination Figure 3 , Figure 4 , Figures 7 to 9 In this embodiment, the cylinder block 31 has an intake pipe 315 communicating with the crankshaft cavity 313 on its side wall, and an exhaust pipe 353 communicating with the secondary exhaust cavity 352 on the secondary cylinder head 35; a primary intake valve 3314 is provided on the primary piston head 3311, and a primary exhaust valve 342 is provided on the primary cylinder head 34; a secondary intake valve 354 and a secondary exhaust valve 355 are provided on the secondary cylinder head 35; wherein, the primary compression cavity receives air from the crankshaft cavity 313 through the primary intake valve 3314 and exhausts air to the primary exhaust cavity 341 through the primary exhaust valve 342; the secondary compression cavity 3121 receives air from the secondary intake cavity 351 through the secondary intake valve 354 and exhausts air to the secondary exhaust cavity 352 through the secondary exhaust valve 355.

[0055] For ease of understanding, we will use an example where the primary cavity 311 and the secondary cavity 312 are located on the upper and lower sides of the crankshaft cavity 313, with the secondary cavity 312 on top:

[0056] The first-stage piston head 3311 has a first-stage intake port that runs vertically through the crankshaft cavity 313 and the first-stage compression cavity. A spring sheet covering the first-stage intake port is provided on the lower surface of the first-stage piston head 3311, which serves as a first-stage intake valve 3314. When the crankshaft 32 drives the connecting bracket 3313 to move upward via the connecting rod 332, the first-stage piston head 3311 moves upward within the first-stage cavity 311, increasing the volume of the first-stage compression cavity and generating negative pressure. At this time, the first-stage intake valve 3314 opens under the pressure difference between the crankshaft cavity 313 and the first-stage compression cavity, allowing air to enter the first-stage compression cavity from the crankshaft cavity 313.

[0057] The first-stage cylinder head 34 is provided with a first-stage exhaust port for connecting the first-stage compression chamber and the first-stage exhaust chamber 341, and the chamber wall of the first-stage exhaust chamber 341 is provided with a spring plate that seals the first-stage exhaust port as a first-stage exhaust valve 342. When the crankshaft 32 drives the connecting bracket 3313 to move downward through the connecting rod 332, the first-stage piston head 3311 moves downward in the first-stage chamber 311, thereby reducing the volume of the first-stage compression chamber, thus compressing the air entering the first-stage compression chamber to do work. When the air pressure in the first-stage compression chamber reaches the target value, the first-stage exhaust valve 342 is opened, thereby allowing the first-stage compressed air to enter the first-stage exhaust chamber 341.

[0058] Meanwhile, as the connecting bracket 3313 moves downward, the second piston head descends within the secondary chamber 312, causing the volume of the secondary compression chamber 3121 to gradually increase and intake to begin. Specifically, the secondary cylinder head 35 has a secondary intake port connecting the secondary intake chamber 351 and the secondary compression chamber 3121, and a secondary exhaust port connecting the secondary exhaust chamber 352 and the secondary compression chamber 3121. A spring plate covering the secondary intake port is provided on the lower surface of the secondary cylinder head 35 as a secondary intake valve 354, and a spring plate covering the secondary exhaust port is provided on the upper surface of the secondary cylinder head 35 as a secondary exhaust valve 355. When the secondary piston head 3312 descends, the pressure within the secondary compression chamber 3121 is lower than that in the secondary intake chamber 351, causing primary compressed air to enter the secondary intake chamber 351 from the primary exhaust chamber 341, and then enter the secondary compression chamber 3121 through the opened secondary intake valve 354.

[0059] When the connecting frame 3313 enters the upward stage again, the primary compression chamber is filled with air, and the secondary piston head 3312 begins to compress the secondary compression chamber 3121 to do work. When the air pressure in the secondary compression chamber 3121 reaches the target value, it opens the secondary exhaust valve 355, so that the compressed high-pressure air enters the secondary exhaust chamber 352 through the secondary exhaust port, and finally flows from the secondary exhaust chamber 352 to the vehicle's air-using units such as the braking system.

[0060] Please refer to the following for operational heat dissipation requirements. Figure 2 , Figure 7 , Figures 10 to 12The aforementioned commercial vehicle brake air compressor also includes a cooling fan 40 and an air guide shroud 50; the cooling fan 40 is rotatably connected to the cylinder 31 and connected to the crankshaft 32 for power take-off, and the air guide shroud 50 is fixed to the cylinder 31 and forms an air guide cavity 500 between the cylinder 31 and the cylinder 31; the outer periphery of the secondary cylinder head 35 forms at least one ring of ventilation holes 357 based on the heat dissipation fins 356, and the ventilation holes 357 are connected to the air guide cavity 500.

[0061] The quality of heat dissipation performance directly affects operational stability and air compression efficiency. Here, an air guide shroud 50 is used to introduce the airflow from the cooling fan 40 into the air guide chambers 500 surrounding the cylinder block 31, thereby achieving air cooling of the cylinder block 31. Furthermore, considering that the second-stage compression generates a large amount of heat while the first-stage compression generates very little, heat dissipation fins 356 are provided on the outer periphery of the second-stage cylinder head 35. The airflow entering the air guide chambers 500 is discharged through a ring of ventilation holes 357 formed by the heat dissipation fins 356. On the one hand, the heat dissipation fins 356 increase the air contact area of ​​the second-stage cylinder head 35, facilitating heat dissipation from the second-stage cylinder head 35 to the air. On the other hand, the airflow passing through the ventilation holes 357 quickly removes heat from the heat dissipation fins 356, thereby improving the heat dissipation efficiency of the second-stage cylinder head 35. This helps to reduce the temperature of the high-pressure air obtained after the second-stage compression, improving operational stability and air compression efficiency.

[0062] In addition, the cooling fan 40 obtains its rotational power directly from the crankshaft 32, which helps to improve the overall compactness of the structure.

[0063] Among some possible implementations, see [link to relevant documentation]. Figure 2 and Figure 6 A cover 37 is provided on the side of the cylinder block 31 opposite to the motor 20. The cooling fan 40 is rotatably connected to the cover 37 via the fan shaft 41. One end of the fan shaft 41 passes into the crankshaft cavity 313 and is provided with an eccentric block 411. The eccentric block 411 is sleeved and fixed to the crankshaft 32.

[0064] The housing cover 37 and the cylinder block 31 are connected by a sealed and detachable method, which helps to reduce the machining difficulty of the cylinder block 31. The fan shaft 41 and the housing cover 37 can be rotated together by bearings. At the same time, a sealing structure is set between the housing cover 37 and the cooling fan 40, which can be a non-contact labyrinth seal. While ensuring the sealing of the bearing, the cooling fan 40 and the housing cover 37 are prevented from interfering with each other's movement, thereby improving the stability and quietness of the cooling fan 40.

[0065] To ensure the stable operation of the cooling fan 40, the fan shaft 41 and the output shaft of the motor 20 should be axially aligned. This requires the fan shaft 41 and the crankshaft 32 to be connected by an eccentric block 411. Furthermore, the distance between the part of the eccentric block 411 and the center of the crankshaft 32 and the center of the fan shaft 41 should be the same as the distance between the crankshaft 32 and the center of the output shaft of the motor 20.

[0066] For details, please refer to Figure 6 Figure 10 and Figure 11 The eccentric block 411 has an eccentric hole 4111, and the end of the crankshaft 32 facing the cooling fan 40 is fitted with an elastic sleeve 321, which is embedded in the eccentric hole 4111.

[0067] The elastic sleeve 321 can be a polymer elastomer. The elastic sleeve 321 connects the eccentric hole 4111 and the crankshaft 32, avoiding the instability of the fan shaft 41 and the crankshaft 32 due to assembly errors, which would lead to increased vibration. This helps to reduce the requirements for the machining and assembly accuracy of the crankshaft 32 and the fan shaft 41.

[0068] For example, in some embodiments, such as Figure 11 As shown, the crankshaft 32 includes a counterweight disc 322 and an eccentric shaft 323; the counterweight disc 322 is coaxially sleeved on the output shaft of the motor 20, and the eccentric shaft 323 is biased and fixed to the counterweight disc 322 and connected to the connecting rod 332; wherein, the counterweight disc 322 has a thinning and weight-reducing part 3221 along its radial edge near the edge of the eccentric shaft 323, and the thinning and weight-reducing part 3221 is provided with a plurality of weight-adjusting holes 3222.

[0069] After the crankshaft 32 is machined, a dynamic balance test is performed. Based on the dynamic balance test results, corresponding adjustment holes 3222 are drilled, or gravity blocks are embedded into existing adjustment holes 3222, until the crankshaft 32 as a whole meets the dynamic balance test requirements.

[0070] By setting a counterweight plate 322, the rotational inertia of the crankshaft 32 can be increased, thereby improving the rotational stability of the crankshaft 32. On the other hand, the thinning and weight-reducing part 3221 can be used to counteract the overall center of gravity shift of the crankshaft 32 caused by the offset of the eccentric shaft body 323. Specifically, the overall center of the crankshaft 32 can be adjusted to coincide with the axis of the output shaft of the motor 20 by adding a weight adjustment hole 3222 or embedding a gravity block in the weight adjustment hole 3222. This ensures that the centrifugal forces of the radially opposite parts of the crankshaft 32 can cancel each other during rotation, thereby avoiding the vibration problem of the whole machine caused by the rotation of the crankshaft 32, and thus reducing the vibration and noise of the whole machine operation.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A commercial vehicle brake air compressor, characterized in that, It includes a base with multi-stage vibration damping, a motor connected to the base and coaxially connected to a compression cylinder; The compression cylinder includes a cylinder body, a crankshaft, and a piston assembly; a primary chamber and a secondary chamber are formed at both ends of the cylinder body, and a crankshaft chamber is formed between the primary chamber and the secondary chamber; the crankshaft is rotatably connected to the crankshaft chamber and coaxially connected to the output shaft of the motor; The piston assembly includes a double-ended piston and a connecting rod; the two ends of the double-ended piston are slidably connected to the first-stage chamber and the second-stage chamber, respectively; one end of the connecting rod is rotatably connected to the crankshaft, and the other end is rotatably connected to the double-ended piston; wherein, the connecting rod drives the double-ended piston to reciprocate along its own axial direction under the drive of the crankshaft. The dual-headed piston includes a connecting frame, a primary piston head, and a secondary piston head; the primary piston head and the secondary piston head are respectively located at both ends of the connecting frame, and are respectively connected to the primary chamber and the secondary chamber. The compression cylinder further includes a primary cylinder head and a secondary cylinder head. The primary cylinder head covers the primary cavity and forms a primary compression cavity between itself and the primary piston head. The secondary cylinder head covers the secondary cavity and forms a secondary compression cavity between itself and the secondary piston head. The first-stage cylinder head is provided with a first-stage exhaust chamber, and the second-stage cylinder head is provided with a second-stage intake chamber and a second-stage exhaust chamber that are isolated from each other; the first-stage exhaust chamber and the second-stage intake chamber are connected by a ventilation passage provided in the cylinder block; The cylinder body forms a mating surface facing the motor. An annular groove is provided on the mating surface. The cylinder wall of the cylinder body has a first air passage and a second air passage communicating with the annular groove. The first air passage communicates with the primary exhaust chamber, and the second air passage communicates with the secondary intake chamber. The motor end cover is sealed to the mating surface and covers the annular groove to form a third air passage. The first air passage, the second air passage, and the third air passage together form the ventilation passage. The cylinder block has an intake pipe on its side wall that communicates with the crankshaft cavity, and an exhaust pipe on the secondary cylinder head that communicates with the secondary exhaust cavity; the primary piston head has a primary intake valve, and the primary cylinder head has a primary exhaust valve; the secondary cylinder head has a secondary intake valve and a secondary exhaust valve. The primary compression chamber receives air from the crankshaft chamber via the primary intake valve and exhausts air into the primary exhaust chamber via the primary exhaust valve; the secondary compression chamber receives air from the secondary intake chamber via the secondary intake valve and exhausts air into the secondary exhaust chamber via the secondary exhaust valve.

2. The commercial vehicle brake air compressor as described in claim 1, characterized in that, The connecting frame has an internal clearance space and a clearance hole communicating with the internal clearance space. The crankshaft passes through the clearance hole, extends into the internal clearance space, and connects to the connecting rod.

3. The commercial vehicle brake air compressor as described in claim 1, characterized in that, The commercial vehicle brake air compressor also includes a cooling fan and an air guide shroud; the cooling fan is rotatably connected to the cylinder and connected to the crankshaft for power take-off, and the air guide shroud is fixed to the cylinder and forms an air guide cavity with the cylinder; the outer periphery of the secondary cylinder head forms at least one ring of ventilation holes based on the heat dissipation fins, and the ventilation holes communicate with the air guide cavity.

4. The commercial vehicle brake air compressor as described in claim 3, characterized in that, The cylinder block is provided with a cover on the side opposite to the motor, and the cooling fan is rotatably connected to the cover via a fan shaft; wherein, one end of the fan shaft passes through the crankshaft cavity and is provided with an eccentric block, and the eccentric block is sleeved and fixed to the crankshaft.

5. The commercial vehicle brake air compressor as described in claim 4, characterized in that, The eccentric block is provided with an eccentric hole, and an elastic sleeve is fitted on the end of the crankshaft facing the cooling fan. The elastic sleeve is embedded in the eccentric hole.

6. The commercial vehicle brake air compressor as described in any one of claims 1-5, characterized in that, The crankshaft includes a counterweight plate and an eccentric shaft; the counterweight plate is coaxially sleeved on the output shaft of the motor, and the eccentric shaft is offset and fixed to the counterweight plate and connected to the connecting rod; wherein, the counterweight plate has a thinning and weight-reducing part along its radial edge near the edge of the eccentric shaft, and the thinning and weight-reducing part is provided with a plurality of weight-adjusting holes.

Images