HIGH-TRANSMISSION-RATIO SUSPENSION SHAFT CENTRIFUGAL SUPERCHARGER WITH PLANETARY GEAR MECHANISM

Abstract

The invention discloses a high-transmission-ratio suspension shaft centrifugal supercharger which comprises a transmission unit, a fan supercharging unit and a cooling unit; the transmission unit is composed of a belt wheel, a planetary gear mechanism, a friction wheel group and a suspension mainshaft, the planetary gear mechanism comprises a sun gear and a planetary gear both installed in a gearbox, the sun gear and the belt wheel are in coaxial installation and rotate together, the planetary gears are distributed at the periphery of the sun gear in a 120 degree symmetric way and are meshed with and follow up the sun gear; the friction wheel group comprises friction wheels arranged in a sealed box and arranged coaxially with corresponding planetary gears; the suspension mainshaft generates contact friction with surfaces of the friction wheels and is driven to rotate together with the friction wheels; the cooling unit is used to pump out high-temperature lubricating oil in the gearbox and the sealed box, and lubricating oil is returned after cooling is performed. According to the invention, the supercharger is substantially improved in transmission precision and speed increasing ratio at a high speed range, and also possesses characteristics of long safe life, convenience for mounting, good heat dispersion performance, low noise and the like.

Claims

1. A high-transmission-ratio suspension shaft centrifugal supercharger with a planetary gear mechanism, said supercharger comprising a transmission unit, a fan supercharging unit and a cooling unit, wherein, said transmission unit (1) is composed of a belt wheel (11), a planetary gear mechanism (12), a friction wheel group (13) and a suspension mainshaft (14), said belt wheel (11) is directly connected to and driven by an automobile engine via a transmission belt; said planetary gear mechanism (2) comprises a sun gear (201) and three planetary gears (202) together arranged in a gearbox (203), said sun gear (201) penetrates said gearbox (203), is coaxially installed with said belt wheel (11) and rotates together with said belt wheel (11), said three planetary gear (202) are distributed at periphery of said sun gear (201) respectively via transmission shafts (204) in a 120 degree symmetric manner, and are all meshed with and follow up said sun gear; said friction wheel group (13) comprises three groups of friction wheels together arranged in a sealed box (131), said three groups of friction wheels, corresponding to said planetary gears (202), are coaxially arranged respectively on said transmission shafts (204) and are divided into front friction wheels at a first same plane and rear friction wheels at a second same plane; a front end and a rear end of said suspension mainshaft (14) generate contact friction respectively with surfaces of said front friction wheels and said rear friction wheels, and said suspension mainshaft (14) is lifted up by taking outer diameters of six friction rings formed by said three groups of friction wheels distributed at a 120-degree interval as support points, and accordingly is driven to rotate together with said friction wheels; additionally, said gearbox (203) is connected to said sealed box (131) as a whole, and internal cavities of said gearbox (203) and said sealed box (131) are in communication and are injected with lubricating oil; said fan supercharging unit (2) comprises a casing (21), an axial air inlet (22) and a radial air outlet (23) arranged on said casing (21), and a centrifugal impeller group (24) and an axial impeller group (25) arranged in said casing (21), said centrifugal impeller group (25) and said axial impeller group (24) are successively fixedly sleeved on the tail end of said suspension mainshaft (14), rotate under driving of said suspension mainshaft, and accelerate an airflow to said radial air outlet (23) from said axial air inlet (22), thereby giving play to supercharging effect; and said cooling unit comprises a gear pump and an oil cooler, wherein said gear pump is installed in said gearbox and used for pumping out lubricating oil heated because of rotation of said sun gear, said planetary gear, said friction wheel and said suspension mainshaft to said oil cooler, and said oil cooler cools lubricating oil and returns lubricating oil to said sealed box (131).

2, The suspension shaft centrifugal supercharger according to claim 1, wherein each of said friction wheels (132) comprises a wheel center (1321), an elastic rubber ring (1322) and a wheel sleeve (1323) successively from inside to outside, said wheel center (1321) is sleeved on said transmission shaft (204) at the central position of said wheel center (1321), and is provided with a plurality of first gears protruding outwards and symmetrically distributed along the peripheral direction on the outer surface; the internal surface of said elastic rubber ring (1322) is provided with a plurality of inner gear slots matched with said first gears, and therefore said elastic rubber ring (1322) is installed on said wheel center (1321) in an inlaying way; said wheel sleeve (1323) is provided with a plurality of second gears protruding inwards and distributed along the peripheral direction on the internal surface, and the outer surface of said elastic rubber ring (1322) also is provided with a plurality of outer gear slots matched with said second gears, and therefore said elastic rubber ring (1322) is installed on said wheel sleeve (1323) in an inlaying way; and additionally, said first gears and said second gears have a same structure and are mutually staggered and symmetrically distributed.

3, The suspension shaft centrifugal supercharger according to claim 1, wherein a gear number ratio of said sun gear (201) to said planetary gear (202) is preferably set as 1:1.5, and a diameter ratio of said friction wheel (132) to said suspension mainshaft (14) is set as 1:4.456, and a total transmission ratio is 6.68.

4, The suspension shaft centrifugal supercharger according to claim 1, wherein said gear pump is replaced by an electric oil pump and is installed outside said gearbox (203).

5, The suspension shaft centrifugal supercharger according to claim 1, wherein said wheel center (1321) is preferably an aluminium alloy wheel center, said elastic rubber ring (1322) is made from hydrogenated nitrile and other materials with a large temperature coefficient span and a small pressure change, and said wheel sleeve (1323) is preferably prepared from bearing steel.

Description

DESTRIPTION OF ACCOMPANYING DRAWINGS

[0022] FIG. 1 illustrates the integral structure and the configuration of a centrifugal supercharger according to an exemplary embodiment of the invention;

[0023] FIG. 2 is an end view of the structure of the transmission system illustrated in FIG. 1;

[0024] FIG. 3 is a section view of the structure of the transmission system illustrated in FIG. 1;

[0025] FIG. 4 illustrates a transmission process between a suspension shaft and the friction wheel;

[0026] In all accompany drawings, same reference numbers represent same elements or structures, in which, 1—transmission unit, 2—fan supercharging unit, 11—belt wheel, 12—planetary gear mechanism, 13—friction wheel group, 14—suspension mainshaft, 21—casing, 22—axial air inlet, 23—radial air outlet, 24—centrifugal impeller group, 25—axial impeller group, 201—sun gear, 202—planetary gear, 203—gearbox, 204—transmission shaft, 131—sealed box, 132—friction wheel, 1321—wheel center, 1322—elastic rubber ring, and 1323—wheel sleeve.

SPECIFIC EMBODIMENT OF THE INVENTION

[0027] For clear understanding of the objectives, technical scheme and advantages of the invention, detailed description of the invention will be given below in conjunction with accompanying drawings and specific embodiments. It should be noted that the embodiments are only meant to explain the invention, and not to limit the scope of the invention. Additionally, technical features referred by embodiments described below may be mutually combined as long as they do not conflict.

[0028] FIG. 1 illustrates the integral structure and the setting way of a centrifugal supercharger constructed according to the invention. As illustrated in FIG. 1, the centrifugal supercharger mainly comprises a transmission unit 1, a fan supercharging unit 2, a cooling unit 3 and other functional units. Aiming at various disadvantages of conventional mechanical superchargers, the invention performs research design on structures and setting ways of the functional units by referring engineering application practice and bench test results (particularly described in background) of previous products of the inventor, so as to facilitate purposes of improving the speed increasing ratio of a complete machine, guaranteeing the supercharging effect at a high-speed stage, reducing noise, improving integral performances and reliability for long-term use and the like.

[0029] Concretely, as illustrated in FIG. 1 and FIG. 2, the transmission unit 1 is composed of a belt wheel 11, a planetary gear mechanism 12, a friction wheel group 13 and a suspension mainshaft 14. The belt wheel 11, for example, is directly connected to a power part of an automobile engine via a transmission belt for power drive. As a key improvement, the planetary gear mechanism 2 comprises a sun gear 201 and three planetary gears 202 together arranged in a gearbox 203, the sun gear 201 has a relatively large diameter, and one end (shown as the left end in FIG. 1) of the sun gear 201 directly penetrates the gearbox 203 and is coaxially installed at a transmission shaft with the belt wheel 11 and rotates together with the belt wheel 11. The three planetary gears 202 have a same structure and a relatively small diameter, are symmetrically arranged at the periphery of the sun gear 201 respectively via transmission shafts 204 and matched planet carriers, and are all meshed with the sun gear 201, and therefore when rotating, the large gear drives the three small gears meshed therewith to synchronously rotate. As an example, the friction wheel groups 13 are divided into three groups, each group comprises two friction wheels respectively arranged at a front position and a rear position (of course, it is acceptable if each group contains more friction wheels, and based on consideration of balance between transmission efficiency and structure compactness, the form of double friction wheels in tandem is selected, and additionally, the friction wheels are preferably distributed radially at a suspension shaft at a 120-degree interval), all friction wheels 32 of the friction wheel groups 13 are all arranged in a sealed box 131, namely in a friction wheel box, and each group of friction wheels is coaxially arranged on a transmission shaft 204 together with a corresponding planetary gear, so that when the planetary gear rotates, the planetary gear drives the group of friction wheels fixedly disposed on the same shaft to synchronously rotate. Furthermore, as illustrated in FIG. 4, the friction wheels, at the front end of the transmission shaft, in the three groups of friction wheels are kept at a same plane, so that the motion trajectory are at a same plane when the friction wheels rotate, and preferably the line of center points of the three front friction wheels form an equilateral triangle, and edges of the three friction wheels together support the front end of the suspension mainshaft as three support points, and drive the suspension mainshaft to rotate through friction contact. The friction wheels, at the rear end of the transmission shaft, in the three groups of friction wheels are kept at another same plane and support the rear end of the suspension mainshaft in the above mentioned same manner, and therefore the rear friction wheels and the front friction wheels act together for executing transmission. Since the front end and the rear end of the suspension mainshaft 14 generate contact friction respectively with surfaces of the three front friction wheels and the three rear friction wheels, synchronous high-speed rotation can be performed even under a bearing-free circumstance.

[0030] Through the above manner, since the transmission system does not need three belt wheels any longer, the problems of empty load between belt wheels and friction wheels and a high sliding ratio are effectively solved, and also installation of the belt wheel to the automobile engine is facilitated, which is very critical for equipment upgrading of various automobiles and expansion of product applicability. Especially, by increasing one order of speed increase in the gearbox, the integral speed increasing ratio is obviously improved compared with an original speed increasing ratio. Based on an example that the gear ratio of the sun gear to the planetary gear is 1:1.5 and the preferable diameter ratio of the friction wheel to the suspension mainshaft is 1:4.456, the rotation speed ratio of the supercharger is 6.68, and the speed increasing ratio from a belt pulley of a main shaft of the engine to a belt pulley of the supercharger is 1:2.5, and therefore, the total transmission ratio is 16.7, that is, the belt wheel, which makes one rotation, drives the suspension mainshaft to make 6.68 rotations, and the rotation speed of the fan impeller group installed on the suspension mainshaft is improved by 16.7 times at the same time, and therefore the speed increase of a wind flow blown from the fan supercharging unit is further increased, the pressure is raised and wind flow is increased, thereby greatly improving work efficiency and supercharging effect.

[0031] The fan supercharging unit 2 comprises a casing, an axial air inlet 22 and an radial air outlet 23 arranged on the casing 21, and a centrifugal impeller group 24 and an axial impeller group 25 arranged in the casing 21. Additionally, the fan supercharging unit 2 can comprise structures such as an axial duct, an impeller chamber, a shelf and the like. The centrifugal impeller group 25 and the axial impeller group 24 are successively fixedly sleeved on the tail end (shown as a right end in FIG. 1) of said suspension mainshaft 14, and accordingly rotate synchronously under driving of the suspension mainshaft, and accelerate an airflow to the radial air outlet 23 from the axial air inlet 22, thereby giving play to supercharging effect; and

[0032] As another key improvement of the invention, the gearbox 203 is connected to the sealed box 131 as a whole, internal cavities of the gearbox 203 and the sealed box 131 are in communication and are injected with lubricating oil; and on the above basis, the invention also is provided with the cooling unit for cooling and temperature decrease. The cooling unit comprises a gear pump and an oil cooler, the gear pump is formed directly by some gears in the gearbox, and is used to pump out lubricating oil heated because of high-speed rotation between the sun gear 201, the planetary gear 202, the friction wheel 132 and the suspension mainshaft 14, and the lubricating oil is sent to the oil cooler for cooling and then returns to the sealed box 131. Additionally, the gear pump can operate to replace an external electric oil pump, thereby further reducing equipment volume and improving structure compactness.

[0033] The reason for the above design comprises that increase of fan power brings very limited cooling effect and rapidly deteriorates system noise status although it is practicable to employ lubricating grease or a fan for cooling in the prior art under the condition of low- and medium-speed rotation since friction force in the transmission unit directly influences the load capacity and the transmission efficiency of the complete machine. By designing the friction wheel box as a sealed box, enabling the friction wheel box and the gear box to be integrally combined and injecting lubricating oil into the communicated cavities, enough lubrication is provided for multiple gears, the friction wheels, the transmission shafts, a bearing and the suspension mainshaft, and also good cooling effect is provided under the premise of no increase in noise. Through the above integral mechanical design, the rotation speed of the centrifugal supercharger mainshaft of the invention has the maximum value improved from previous 72000 r/min to more than 100000 r/min, and results of the bench continuous speed-changing test show that the continuous working time is improved from 1000 h of a previous generation product to 3000 h or more, and therefore the centrifugal supercharger of the invention has greater practical application value.

[0034] FIG. 3 is a section view of the structure of the novel friction wheel designed according to the invention. As another key improvement of the invention, the friction wheel plays an important role in improving the maximum rotation speed, guaranteeing rotation precision, guaranteeing reliability of long-term operation and the like.

[0035] Concretely, each friction wheel 132 comprises a wheel center 1321 (of an aluminium wheel, for example), an elastic rubber ring 1322 and a wheel sleeve 1323 successively from inside to outside, the wheel center is sleeved on a corresponding transmission shaft 204 at the central position of the wheel center, and is provided with a plurality of first gears protruding outwards and symmetrically distributed along the peripheral direction on the outer surface; the internal surface of said elastic rubber ring 1322 is provided with a plurality of inner gear slots matched with said first gears, and therefore the elastic rubber ring 1322 is installed on the wheel center 1321 in a tight inlaying way; the wheel sleeve 1323 is provided with a plurality of second gears protruding inwards and distributed along the peripheral direction on the internal surface, and the outer surface of the elastic rubber ring 1322 also is provided with a plurality of outer gear slots matched with the second gears, and therefore the elastic rubber ring 1322 is installed on the wheel sleeve 1323 in an inlaying way; and additionally, the first gears and the second gears have a same structure and are mutually staggered and symmetrically distributed.

[0036] After each of the friction wheels is assembled according to the above designed concrete structure, the elastic rubber ring possesses an expansion force, and also inner and outer gear slots, in which the first gears and the second gears are respectively inlayed, are provided, and therefore precise cooperation between the wheel center and the wheel sleeve is further guaranteed, as well as the transmission precision. When the aluminium wheel rotates, the gears of the aluminium wheel pushes the rubber components, the rubber components gear slots drive the rubber rings, and the rubber rings drive the center shaft to rotate, and at the moment the rubber components mainly only bear radial circumferential extrusion force and are basically not subjected to pulling force, so the service life of the rubber components is prolonged, and more important, the peak value of the rotation speed of the friction wheels is further improved, and periodic slip between the center shaft and the friction wheels or failure of the whole supercharging system does not happed even the system operates at an extremely high speed.

[0037] To summarize, the suspension shaft centrifugal supercharger with the planetary gear mechanism according to the invention is capable of improving the power and the torque of an engine and also substantially improving the transmission precision and the speed increasing ratio of the whole machine after the machine operates at a high-speed stage, also possesses characteristics of long safe life, convenience to load and install, good heat dispersion, low noise and the like, and accordingly is especially applicable to engines of various crankshaft connecting rod systems and family cars, agricultural automobiles and other vehicles with the displacement of, for example, 1.4 L and 1.6 L, and gives play to effects of improving power, increasing torque and reducing emission.

[0038] While preferred embodiments of the invention have been described above, the invention is not limited to disclosure in the embodiments and the accompanying drawings. Any changes or modifications without departing from the spirit and the principle of the invention fall within the scope of the invention.