A planetary hydraulic continuously variable transmission

Abstract

A planetary hydraulic continuously variable transmission can be in the form of only the NGW planetary gear train, or in the form of the NGW planetary gear train with an axially connected planetary gear type internal gear pump with fewer teeth difference. The locking shaft 8 of its planetary gear is composed of an adjusting sleeve with internal and external thread to form a sun gear and an original clearance adjusting device for the two end faces of the planetary gears and the inner side of the planet carrier. At the inner end faces of the left and right side plates of the planet carrier and the inner end faces of the left and right walls with fewer teeth difference, new self-pressurizing groove type hydrostatic mechanical seal pairs are arranged at both ends of the planetary gears and the internal gear respectively, so as to form a high-pressure oil pump device with dynamic seal. The present invention can be used in automobiles and construction machinery with starting buffer devices, and can also be used in pure mechanical transmission modes.

Description

Technical Field

[0001] The present invention relates to a speed reduction device, in particular to a planetary speed reduction device, specifically a planetary hydraulic continuously variable transmission, which can be in the form of only the NGW planetary gear train or in the form of an NGW planetary gear train with an axially connected planetary gear less tooth difference internal gear pump. Background Art

[0002] As is well known, the fluid couplings and torque converters of the hydrodynamic type are used in existing vehicles and construction machinery to start the buffer device. Their common drawbacks are: they are independent individual components from the planetary gear sets of the transmission device. The diameter of the torque converter is much larger than the planetary gear set at its rear, with a large volume and complex structure. According to the "Mechanical Design Handbook" Volume 5 edited by Xu Hao, pages P39 - 62; 39 - 88, the technical indicators of the existing fluid couplings and torque converters are as follows: 1. The pressure range is about 25 - 1.5 MPa. 2. The efficiency is 0 - 83%. 3. The torque ratio of the torque converter is: i = 1 - 3. Summary of the Invention

[0003] The object of the present invention is to design a planetary hydraulic continuously variable transmission with a small volume, high efficiency, and large torque ratio in view of the problems of large volume, low efficiency, and small torque ratio existing in the existing speed change mechanisms (fluid couplings and torque converters).

[0004] The technical solution of the present invention is as follows:

[0005] A planetary hydraulic continuously variable transmission, namely an NGW planetary hydraulic single-rotation differential continuously variable transmission device with integrated mechanical and hydraulic components. It can be in the form of only an NGW planetary gear train, or in the form of an NGW planetary gear train with an axial-coupled planetary gear less-tooth difference internal gear pump. The characteristics of the hydraulic mechanical transmission device with only the NGW planetary gear train are as follows: The single NGW type device is composed of a one-way sun gear 1, multiple planetary gears 2, left and right planetary carrier side plates 4 of the internal gear 3, and an oil tank 6. The liquid hydrostatic oil circuit is formed by the oil inlet cavity 14 communicating with the oil tank, the outer diameter of the tooth tip of the internal gear 3 and the inner body of the planetary carrier. A high-pressure oil cavity 15 is formed at the intersection of the internal gear 3 and the planetary gear 2, which plays a braking and buffering role for the internal gear 3. On one side of the sun gear 1 is a high-pressure oil cavity 15' that has a pushing effect on the planetary gear 2 and the sun gear 1. An arc-shaped groove (31) or a through hole is opened on the planetary carrier block at the axial center position of the sun gear 1 to communicate with the oil cavity 15. On the other side of the sun gear 1 is an oil discharge cavity 14' leading to the oil tank; For the hydraulic mechanical transmission device formed by coupling the above NGW type transmission device with an axial planetary gear less-tooth difference internal gear pump 16, the outer diameter of the internal gear 3 of the NGW type transmission device is fixedly connected to the outer diameter of the internal gear ring 17 of the planetary gear less-tooth difference internal gear pump 16. The outer edge of the left side wall 18 of the planetary gear less-tooth difference internal gear pump 16 is fixedly connected to the inner edge of the internal gear ring 17. The center of the external gear 24 of the planetary gear less-tooth difference internal gear pump 16 has an eccentricity with the center of the internal gear ring 17. The two ends of the crescent-shaped part 20 formed between their outer diameter and inner diameter are respectively fixedly connected to the left side wall 18 and the right side wall 19 that is fixedly connected to the box body to form a low-pressure oil cavity 21 and a high-pressure oil cavity 22 communicating with the oil tank. The high-pressure oil formed by the high-pressure oil cavity 22 enters the axial oil circuit 25 at the center of the output shaft 5 through the dynamic seal part 23 on the outer edge of the output shaft 5 and the oil circuit 26 in the right side wall 19, and then passes through the radial oil circuit 30 of the right planetary carrier side plate 4 to reach the high-pressure oil cavity 15' in the NGW type seat (planetary seat), and is superimposed with the pressure of the high-pressure oil cavity 15 to form a starting buffer device for heavy vehicles.

[0006] At the inner end faces of the left and right planetary carrier side plates 4 on both ends of each of the planetary gears 2 and the internal gear 3, there is a self-pressurizing groove type liquid hydrostatic mechanical seal pair 13, which is composed of processing thin cylindrical cavities 10 at both ends of each of the planetary gears 2 and the internal gear 3. There are several axial oil circuits 29 leading from the tooth root holes 27 through one-way valves 28 at both ends to this cavity, and are composed of gaskets 11 correspondingly arranged on the inner sides of the two planetary carrier side plates 4.

[0007] Original clearance adjustment device elements 7, 8, 9 are arranged on the inner side of the planetary carrier side plate 4.

[0008] When the inner cavity of the oil tank 6 is emptied of oil by an accumulator, a pure mechanical transmission mode device with the outer edge of the internal gear 3 braked by a brake pad or a ratchet.

[0009] When the sun gear shaft (32) is input from one end of the planetary gear differential internal gear pump (16), the high-pressure oil chamber (22) of the planetary gear differential internal gear pump (16) is connected to the high-pressure oil chamber (15') through the axial oil passage in the hollow sleeve (33) of the body connected to the right side plate (4) of the planet carrier through the radial oil passage (19)' on the right wall (19).

[0010] The present invention is a planetary gear train one-way transmission device with a combined mechanical and hydraulic element. The prime mover and the output shaft rotate in the clockwise direction.

[0011] Advantages of the present invention:

[0012] The present invention can be used in automobiles, construction machinery, etc. with starting buffer devices to replace traditional fluid couplings and torque converters. It has the advantages of small size, high efficiency, and large torque ratio. The volume of the transmission of the present invention is only 50% of the traditional volume, the efficiency can reach 93%, and the torque ratio > 4. Description of the drawings

[0013] Figure 1 is an axial partial sectional view of the combined mechanical and hydraulic element with three planetary gears, the local NGW gear train, and the axial connection of the planetary gear differential internal gear pump in the embodiment of the present invention.

[0014] Figure 2 is Figure 1 the sectional view in the A - A direction of

[0015] Figure 3 is the schematic diagram of the planetary gear differential internal gear pump of the present invention.

[0016] Figure 4 is the partial sectional view when the sun gear shaft 32 is input from one end of the planetary gear differential internal gear pump.

[0017] In the figure: 1 is the sun gear, 2 is the planetary gear, 3 is the internal gear, 4 is the side plate of the planet carrier, 5 is the output shaft, 6 is the fuel tank, 7 is the internal and external thread adjusting sleeve, 8 is the pin shaft, 9 is the bushing with internal thread, 10 is the thin cylindrical cavity, 11 is the gasket, 12 is the through-hole cylindrical cavity, 13 is the liquid hydrostatic mechanical seal pair (composed of the thin cylindrical cavity 10, the gasket 11, the tooth root hole 27, the one-way valve 28, and the axial oil passage 29), 14 is the oil inlet chamber, 14' is the oil discharge chamber, 15 is the high-pressure oil chamber, 15' is the high-pressure oil chamber, 16 is the internal gear pump, 17 is the internal gear ring, 18 is the left wall, 19 is the right wall, 19' is the radial oil passage on the right wall, 20 is the crescent body, 21 is the low-pressure oil chamber, 22 is the high-pressure oil chamber, 23 is the seal, 24 is the external gear, 25 is the axial oil passage, 26 is the oil passage, 27 is the tooth root hole, 28 is the one-way valve, 29 is the axial oil passage, 30 is the radial oil passage, 31 is the arc-shaped groove, 32 is the sun gear shaft, 33 is the hollow sleeve. Detailed implementation manners

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

[0019] Embodiment 1.

[0020] As Figure 1-2 shown.

[0021] A planetary hydraulic continuously variable transmission, only in the form of an NGW planetary gear train, is composed of a one-way sun gear 1, multiple planetary gears 2, an internal gear 3, left and right planetary carrier side plates 4, and an oil tank 6. As Figure 2 shown, the hydrostatic oil circuit is formed by an oil inlet cavity 14 communicating with the oil tank, the outer diameter of the tooth tip of the internal gear 3 and the inner body of the planetary carrier. A high-pressure oil cavity 15 that brakes and buffers the internal gear 3 is formed at the intersection of the internal gear 3 and the planetary gear 2. On one side of the sun gear 1 is a high-pressure oil cavity 15' that pushes the planetary gear 2 and the sun gear 1. An arc-shaped groove (31) or a through hole is opened on the planetary carrier block at the axial center position of the sun gear 1 to communicate with the oil cavity 15. On the other side of the sun gear 1 is an oil discharge cavity 14' leading to the oil tank. As Figure 1 shown, self-pressurizing groove-type hydrostatic mechanical seal pairs 13 are provided on the inner end faces of the two ends of each planetary gear 2 and the internal gear 3 on the inner side of the left and right planetary carrier side plates 4. It is composed of thin cylindrical cavities 10 machined at both ends of each planetary gear 2 and the internal gear 3. Several axial oil paths 29 starting from the tooth root holes 27 and having one-way valves 28 at both ends lead to this cavity, and are composed of gaskets 11 correspondingly arranged on the inner sides of the two planetary carrier side plates 4. Original clearance adjustment device elements 7, 8, and 9 are provided on the inner side of the planetary carrier side plate 4. When the inner cavity of the oil tank 6 is emptied of oil by an accumulator, the outer edge of the internal gear 3 is in a pure mechanical transmission mode device braked by a brake pad or a ratchet.

[0022] Embodiment 2.

[0023] As Figure 1-4 shown.

[0024] A planetary hydraulic continuously variable transmission, a hydro-mechanical transmission device composed of an NGW planetary gear train and an axial planetary gear differential internal gear pump 16 in series, is composed of a one-way sun gear 1, multiple planetary gears 2, an internal gear 3, left and right planetary carrier side plates 4, and an oil tank 6. As Figure 1 shown. The outer diameter of the internal gear 3 is fixedly connected to the outer diameter of the internal gear ring 17 of the planetary gear differential internal gear pump 16. The outer edge of the left side wall 18 of the planetary gear differential internal gear pump 16 is fixedly connected to the inner edge of the internal gear ring 17. The center of the external gear 24 of the planetary gear differential internal gear pump 16 has an eccentricity with the center of the internal gear ring 17. The two ends of the crescent member 20 formed between their outer diameter and inner diameter are respectively fixedly connected to the left side wall 18 and the right side wall 19 that is fixedly connected to the box body and is in a static state to form a low-pressure oil cavity 21 and a high-pressure oil cavity 22 communicating with the oil tank ( Figure 3). When the sun gear shaft 32 inputs from the left towards the planet carrier side plate 4, the high-pressure oil formed in the high-pressure oil chamber 22 enters the axial oil passage 25 at the center of the output shaft 5 through the oil passage 26 in the right side wall 19 at the position of the dynamic seal 23 on the outer edge of the output shaft 5, and then passes through the radial oil passage 30 of the right planet carrier side plate 4 to reach the high-pressure oil chamber 15' in the NGW planet carrier, and is superposed with the pressure of the high-pressure oil chamber 15 ( Figure 1 ); when the sun gear shaft 32 inputs from one end of the cycloid gear pump 16 with fewer teeth, the high-pressure oil chamber 22 of the cycloid gear pump 16 with fewer teeth passes through the radial oil passage 19' in its right wall 19 and reaches the high-pressure oil chamber 15' through the axial oil passage in the hollow sleeve 33 connected to the right side plate 4 of the planet carrier, and is superposed with the pressure of the high-pressure oil chamber 15 ( Figure 4 ). As Figure 1 shown, self-pressurizing groove type hydrostatic mechanical seal pairs 13 are arranged at the inner end faces of both ends of the respective planet gears 2 and the internal gear 3 on the inner side of the left and right planet carrier side plates 4. It is composed of thin cylindrical cavities 10 machined at both ends of the planet gears 2 and the internal gear 3. There are several axial oil passages 29 leading from the tooth root holes 27 to this cavity through one-way valves 28 at both ends and are composed of gaskets 11 arranged on the inner sides of the two planet carrier side plates 4. Original clearance adjustment device elements 7, 8, and 9 are arranged on the inner side of the planet carrier side plate 4. When the inner cavity of the fuel tank 6 is emptied of oil by the accumulator, the outer edge of the internal gear 3 is a pure mechanical transmission mode device with brake pads or ratchet brakes.

[0025] Specifically, it is preferred that the planetary gear train adopts a three-planet NGW. The gear machining accuracy reaches above grade 7, and the tooth profile is preferably carburized, quenched, and polished. The two end faces of the three planet gears and the internal gear are machined in place on a surface grinder. The original clearance between the two planet carriers and the ends of the gears is preferably 20 - 40 μm. The thin cylindrical cavities 10 at both ends of the internal gear 3 and the planet gears 2 are machined by vertical milling, and the gaskets 11 are preferably machined by a digital wire cutting machine.

[0026] The working principle of the present invention is:

[0027] The establishment of the hydrostatic dynamics of the present invention is:

[0028] a. Before startup, low-pressure oil has entered the tooth space oil inlet chamber 14 of the planet gears 2 and the internal gear 3. The high-pressure oil chamber 15' in the forward direction of the sun gear supplies high-pressure oil from the high-pressure oil chamber 22 of the cycloid gear pump with fewer teeth.

[0029] b. Before startup: The loads M of the output shaft 5 and the planet carrier 4 are approximately ∞.

[0030] c. After startup:

[0031] c-1. The internal gear 3 rotates counterclockwise at high speed. The establishment of the high-pressure oil circuit depends on the relative movement between the outer diameter of the solid part of the planetary carrier side plate 4 and the internal gear 3 to bring the oil in the oil inlet chamber 14 to the oil chamber 15, forming a high-pressure oil chamber. The relative movement at different speeds forms a differential. During this process, the planetary gears 2 and the dynamic oil circuit sealing devices at both ends of the internal gear 3, namely the hydrostatic mechanical seal pair 13, prevent oil leakage, forming a planetary device with sufficient conditions for high-pressure differential. At the same time, the high-pressure oil from the differential pump 16 increases the oil pressure at the high-pressure oil chamber 15, that is, the torque increases.

[0032] c-2. The oil on one side 15'→14' where the planetary gears 2 mesh with the sun gear 1 is discharged into the fuel tank through the oil discharge chamber 14'.

[0033] The dynamic oil circuit sealing device at both ends of the planetary gears 2 and the internal gear 3 adopts an innovative hydrostatic seal pair 13. The high-pressure oil is stored in the cylindrical cavities 10 at both ends of the gears through the tooth root holes 27, axial oil circuits 29, and one-way valves 28, corresponding to the gaskets 11 to form a self-supplying hydrostatic friction pair 13 mechanism (the traditional double-sided groove gaskets are difficult to handle at the intersection of two teeth).

[0034] There is a static oil circuit sealing gap reserved between the gasket 11 and the cylindrical cavity 10 by the components 7, 8, and 9. The internal space of the left and right planetary carrier side plates 4, except for the space occupied by the gears, is a solid and is integrated with the left planetary carrier side plate 4. There is a dynamic gap between the outer diameter of the solid and the top diameter of the teeth of the internal gear 3 (when the planetary carrier side plate 4 and the internal gear 3 are in relative motion), forming a pressurizing oil circuit. There is a dynamic gap between the internal solid of the planetary carrier side plate 4 and the top diameter of the teeth of the planetary gears 2.

[0035] The high-pressure oil from the high-pressure oil chamber 15 through the arc-shaped groove makes the oil chamber 15 a high-pressure chamber. If the arc-shaped groove from 15 to 15' is not opened and 15' is not a high-pressure chamber, the high pressure in the 15 chamber also has a braking effect on the internal gear 3 and the planetary gears 2, and the moving pair cannot be established. The high pressure in 15' and the high pressure in the 15 chamber make the planetary gears 2 in a hydraulic balance state, and 15' has a pushing effect on the sun gear 1, presenting a working condition of superposition of mechanical and hydraulic torques, and discharging oil through the 14' hole.

[0036] The parts not involved in the present invention are the same as the prior art or can be implemented by the prior art.

Claims

1. A planetary hydraulic continuously variable transmission, characterized in that: It consists of a one-way sun gear (1), multiple planet gears (2), an internal gear (3), left and right planet carrier side plates (4), and an oil tank (6). The hydrostatic oil circuit is formed by an oil inlet cavity (14) communicating with the oil tank, the tooth tips of the internal gear (3), and the outer diameter of the planet carrier side plate (4). A second high-pressure oil cavity (15) that brakes and buffers the internal gear (3) is formed at the intersection of the internal gear (3) and the planet gears (2). On one side of the sun gear (1) is a third high-pressure oil cavity (15') that pushes the planet gears (2) and the sun gear (1). An arc-shaped groove (31) or a through hole is opened on the planet carrier side plate (4) at the axial center position of the sun gear (1) to communicate with the second high-pressure oil cavity (15). On the other side of the sun gear (1) is an oil discharge cavity (14') leading to the oil tank; the outer diameter of the internal gear (3) is fixedly connected to the outer diameter of the internal gear ring (17) of the planetary gear pump with small tooth difference (16). The outer edge of the left side wall (18) of the planetary gear pump with small tooth difference (16) is fixedly connected to the inner edge of the internal gear ring (17). The center of the outer gear (24) of the planetary gear pump with small tooth difference (16) has an eccentricity with the center of the internal gear ring (17). A crescent part (20) is formed between the outer diameter of the outer gear (24) and the inner diameter of the internal gear ring (17). The two ends of the crescent part (20) are respectively fixedly connected to the left side wall (18) and the right side wall (19) that is fixedly connected to the box body and is in a static state to form a low-pressure oil cavity (21) and a first high-pressure oil cavity (22) communicating with the oil tank. The high-pressure oil formed by the first high-pressure oil cavity (22) enters the axial oil circuit (25) at the center of the output shaft (5) through the oil circuit (26) in the right side wall (19) and the dynamic seal part (23) on the outer edge of the output shaft (5), and then passes through the radial oil circuit (30) of the right planet carrier side plate (4) and reaches the third high-pressure oil cavity (15'), where it is superimposed with the pressure of the second high-pressure oil cavity (15).

2. The planetary hydraulic continuously variable transmission according to claim 1, wherein: Self-pressurizing groove-type hydrostatic mechanical seal pairs (13) are arranged at the inner end faces of the left and right sides of the respective ends of the planet gears (2) and the internal gear (3). It is composed of thin cylindrical cavities (10) machined at the two ends of the planet gears (2) and the internal gear (3) and corresponding gaskets (11) arranged on the inner sides of the two planet carrier side plates (4). Several tooth root holes (27) reach the cylindrical cavity (10) through the axial oil circuit (29) with one-way valves (28) at both ends.

3. The planetary hydraulic continuously variable transmission according to claim 1, characterized in that: Original clearance adjustment device elements (7, 8, 9) are arranged on the inner side of the planet carrier side plate (4).

4. The planetary hydraulic continuously variable transmission according to claim 1, characterized in that: When the inner cavity of the oil tank (6) is emptied of oil by an accumulator, the outer edge of the internal gear (3) is braked by a brake pad or a ratchet.

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