Balanced differential type planetary gear speed reducer

Abstract

The utility model discloses a balanced differential type planetary gear speed reducer, and belongs to the field of machinery. Technical implementation elements comprise a group of input side planetary gears, a planet carrier and shell, an inner gear ring and a sun gear with an input shaft; the input side planetary gear is provided with an input shaft, the output side planetary gear is provided with a planetary carrier with an output shaft, and the sun gear is coaxially connected with the input shaft; one input shaft is in duplex connection with two sun gears and also serves as a sun gear shaft; one cylindrical structure is in duplex connection with two inner gear rings; the input axis, the output axis and the axis of the inner gear ring all coincide; the shell restrains the sun shaft as an input shaft and restrains the central shaft of the planet carrier as an output shaft through a bearing; an input side sun gear of the duplex sun gear shaft is meshed with an input side planetary gear, a planet carrier of the input side planetary gear serves as a part of a connecting shell, and the input side planetary gear is meshed with an input side inner gear ring. An output side sun gear of the duplex sun gear shaft is meshed with an output side planet gear, a planet carrier of the output side planet gear serves as an output shaft, the output side planet gear is meshed with an output side inner gear ring, and the duplex sun gear can be widely applied to the mechanical industry.

Description

[Technical Field]

[0001] The present invention belongs to the field of mechanical technology. Specifically, it is an improved harmonic reducer with a small tooth difference, which is a gear reduction structure that uses differential to achieve a high reduction ratio under a large tooth type. [Background Art]

[0002] Planetary reducers are widely used industrial products, used to reduce the speed and increase the output torque, and are used in industries such as lifting, excavation, transportation, and construction.

[0003] Working principle: An internal gear ring (A) is tightly combined with the gearbox housing. There is a sun gear (B) driven by external power at the center of the ring gear. Between the two, there is a set of planetary gear sets (C) composed of three gears equally divided and combined on a tray. This set of planetary gears rely on the output shaft, internal gear ring, and sun gear to float in the middle; when the input side power drives the sun gear, it can drive the planetary gears to rotate self - rotatably, and follow the trajectory of the internal gear ring to revolve around the center. The rotation of the planet drives the output shaft connected to the tray to output power.

[0004] The main transmission structure of the planetary reducer is: planetary gears, sun gears, and internal gear rings. The internal gears of the planetary reducer are made of 20CrMnTi through carburizing, quenching, and grinding, and have the characteristics of small volume, light weight, high load - bearing capacity, long service life, stable operation, low noise, large output torque, large speed ratio, high efficiency, and safe performance. It also has the characteristics of power splitting and multi - tooth meshing. It is a new type of reducer with wide versatility. The maximum input power can reach 104 kW. It is applicable to industrial sectors such as lifting and transportation, construction machinery, metallurgy, mining, petrochemical, construction machinery, light industry and textile, medical equipment, instrumentation, automobiles, ships, weapons, and aerospace. New varieties in the planetary series include WGN fixed - axis transmission reducers, WN parent - child gear transmission reducers, and elastic equal - load reducers with a small tooth difference.

[0005] Series: The number of sets of planetary gears. Since a single set of planetary gears cannot meet a large transmission ratio, sometimes 2 or 3 sets are required to meet the requirements of users for a large transmission ratio. Due to the increase in the number of planetary gears, the length of a 2-stage or 3-stage speed reducer will increase, and the efficiency will decrease. Backlash: Fix the output end, rotate the input end clockwise and counterclockwise, and when a rated torque of +-2% torque is generated at the input end, there is a small angular displacement at the input end of the speed reducer. This angular displacement is the backlash. The unit is "minute", which is one-sixtieth of a degree. Some people also call it backlashes. With the continuous development of the speed reducer industry, more and more enterprises are using speed reducers. Planetary speed reducers are industrial products. Planetary speed reducers are a transmission mechanism. Its structure consists of an internal gear ring tightly combined with the gearbox housing. There is a sun gear driven by external power at the center of the ring gear. Between the two, there is a set of planetary gear sets composed of three gears equally divided on a tray. This set of planetary gears relies on the output shaft, internal gear ring, and sun gear to float in between; when the power on the input side drives the sun gear, it can drive the planetary gears to rotate on their own axes and revolve around the center along the trajectory of the internal gear ring. The rotation of the planets drives the output shaft connected to the tray to output power. Using a gear speed converter to reduce the rotational speed of the motor (motor) to the required rotational speed and obtain a larger torque mechanism. Among the speed reducer mechanisms used to transmit power and motion, planetary speed reducers belong to precision speed reducers, and the reduction ratio can be accurate to 0.1 to 0.5 revolutions per minute.

[0006] Main advantages and disadvantages of planetary speed reducers:

[0007] * High load-carrying capacity. In harmonic drive, the meshing of tooth with tooth is surface contact, and the number of simultaneously meshing teeth (contact ratio) is relatively large. Therefore, the load per unit area is small, and the load-carrying capacity is higher than other transmission forms.

[0008] * Large transmission ratio. The transmission ratio of a single-stage harmonic gear drive can reach i = 70 - 500.

[0009] * Small size and light weight.

[0010] * High transmission efficiency and long service life.

[0011] * Smooth transmission, no impact, no noise, and high motion accuracy.

[0012] * Since the flexspline bears large alternating loads, the requirements for the fatigue strength, machining, and heat treatment of the flexspline material are relatively high, and the process is complex. [Summary of the Invention]

[0013] The object of the present invention:

[0014] In order to overcome the defects of the above-mentioned existing technologies and simplify the planetary gear reduction structure, the object of the present invention is to provide a speed reducer with a simple and compact structure, a wide transmission ratio range, which can achieve a very high reduction ratio, and even the reduction ratio tends to infinity.

[0015] The features of the present invention are: compact structure, high transmission efficiency and transmission frequency, and long service life.

[0016] The key technology of the present invention: adopting a differential method, using a differential sun gear and an internal gear ring to drive the planetary gears to obtain speed reduction.

[0017] Specific invention content:

[0018] The present invention discloses an equalizing differential planetary gear speed reducer.

[0019] Technical implementation elements: The present invention is implemented by adopting the following technical solutions, including a group of input-side planetary gears, a planet carrier and a housing, an internal gear ring, and a sun gear with an input shaft; a group of output-side planetary gears, a planet carrier with an output shaft, an internal gear ring, and a sun gear coaxially connected to the input shaft; an input shaft with two sun gears in series also serving as a sun gear shaft; a cylindrical structure with two internal gear rings in series; the input axis, the output axis, and the internal gear ring axis all coincide; the housing restricts the sun shaft as the input shaft through bearings, and restricts the central axis of the planet carrier as the output shaft; the input-side sun gear of the double sun gear shaft meshes with the input-side planetary gears, the planet carrier of the input-side planetary gears serves as a part of the connecting housing, and the input-side planetary gears mesh with the input-side internal gear rings; the output-side sun gear of the double sun gear shaft meshes with the output-side planetary gears, the planet carrier of the output-side planetary gears serves as the output shaft, and the output-side planetary gears mesh with the output-side internal gear rings. The number of input-output side planetary gears and output-side planetary gears is 3 - 10 respectively.

[0020] The speed reduction principle of the present invention is differential speed reduction. The calculated speed reduction ratio formula is as follows:

[0021] Let: the pitch circle radius of the input-end sun gear be R1; the radius of the gear ring be R2; the pitch circle radius of the output-end sun gear be R3; the radius of the gear ring be R4; the rotational speed (angular velocity) of the input sun shaft be ω1;

[0022] Then, the rotational speed of the gear ring ω2 = (R1 / R2) x ω1; thus, the rotational speed of the output-end planet carrier:

[0023] ω3 = ω2(ω1 / ω2 - R4 / R3) / (1 + R4 / R3)

[0024] ω3 = [R2 / R1(R2 / R1 - R4 / R3) / (1 + R4 / R3)]ω1

[0025] Therefore, when the input shaft inputs an angular velocity ω1, the angular velocity ω3 of the output shaft is very small when R2 / R1 and R4 / R3 are close, and the reduction ratio is very large. Even when R2 / R1 - R4 / R3 = 0, an infinite reduction ratio is obtained.

[0026] Furthermore, the sun shaft can also be fixed to the housing, and the internal gear ring can be used as the input shaft. Similarly, the planet carrier on the output side can be used as the output shaft.

[0027] *The above describes the basic principles and main features of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

[0028] Advantages of the present invention:

[0029] The present invention has a simple and compact structure, a scientific deceleration principle, a wide range of transmission ratios, can achieve an ultra-high reduction ratio and even an infinite reduction ratio, and has a relatively broad market prospect. [BRIEF DESCRIPTION OF THE DRAWINGS]

[0030] The following further describes the present invention with reference to the preferred embodiments of the present invention in conjunction with the accompanying drawings:

[0031] Figure 1 It is a schematic diagram of the overall structure of a balanced differential planetary gear reducer;

[0032] Figure 2 It is a schematic diagram of the internal structure and explosion of a balanced differential planetary gear reducer;

[0033] Figure 3 It is a schematic diagram of the double gear ring, double sun gear and shaft structure of the present invention;

[0034] Label description:

[0035] 1. Double sun gear

[0036] 1-1 Sun gear A

[0037] 1-2 Sun gear B

[0038] 1-3 Input sun shaft

[0039] 2. Double internal gear ring

[0040] 2-1 Ring gear C

[0041] 2-2 Ring gear D

[0042] 2-3 Cylinder

[0043] 3. Planet Gear E

[0044] 4. Planet Gear F

[0045] 5. Planet Carrier

[0046] 5-1 Bracket Disc

[0047] 5-2 Bracket Shaft

[0048] 5-3 Planet Shaft

[0049] 6. Housing

[0050] 7. Input Side

[0051] 8. Output Side

[0052] 9. Axis

[0053] 10. Observation Direction

[0054] 11. Planet Shaft Hole [Detailed Implementation Manner]

[0055] As Figure 1 , Figure 2 , Figure 3 shown:

[0056] Refer to Figure 1 and Figure 2 , a balanced differential planetary gear speed reducer, including a set of planet gear E (3) on the input side (7), a set of planet gear F (4) on the output side (8), a planet carrier (5), a double sun gear (1), a double internal gear ring (2) and a housing (6); the integrated structure of the double sun gear (1) includes an input sun shaft (1-3), sun gear A (1-1), and sun gear B (1-2); the integrated structure of the double internal gear ring (2) and the housing (6) includes a gear ring C (2-1) and a gear ring D (2-2) machined on the inner side of the same cylinder (2-3); the bracket shaft (5-2) and the planet shaft (5-3) are installed on the bracket disc (5-1) of the planet carrier (5).

[0057] Looking along Figure 3 the observation direction (10), as Figure 3 shown by the double gear ring, double sun gear and shaft structure: the input sun shaft (1-3) synchronously drives the sun gear A (1-1) and the sun gear B (1-2) to rotate, and a gear ring C (1-1) and a gear ring D (1-2) are coaxially machined on the inner side of the cylinder (1-3).

[0058] Detailed description of the technical implementation: The two sun gears of the input shaft double gear also serve as the sun gear shaft; the two internal gear rings of the cylindrical structure are all coincident with the input axis, the output axis, and the internal gear ring axis on the axis (9); the housing restricts the sun shaft as the input shaft through bearings, and restricts the central axis of the planet carrier as the output shaft; the input-side sun gear of the double sun gear shaft meshes with the input-side planet gear, and the planet carrier of the input-side planet gear serves as a part of the connecting housing, and restricts the planet gear E (3) through the planet shaft hole (11); the input-side planet gear meshes with the input-side internal gear ring; the output-side sun gear of the double sun gear shaft meshes with the output-side planet gear, the planet carrier of the output-side planet gear serves as the output shaft, the output-side planet gear meshes with the output-side internal gear ring, and the number of input-output side planet gears and output-side planet gears is 3-10 respectively.

[0059] The deceleration principle of the present invention is differential deceleration, and the deceleration ratio formula is calculated as follows:

[0060] Set: the pitch circle radius R1 of the input-end sun gear; the tooth ring radius R2; the pitch circle radius R3 of the output-end sun gear; the tooth ring radius R4; the rotational speed (angular velocity) of the input sun shaft is ω1;

[0061] Then, the rotational speed of the tooth ring ω2 = (R1 / R2) x ω1; then: the revolution speed of the output-end planet carrier:

[0062] ω3 = ω2(ω1 / ω2 - R4 / R3) / (1 + R4 / R3)

[0063] ω3 = [R2 / R1(R2 / R1 - R4 / R3) / (1 + R4 / R3)]ω1

[0064] Therefore, when the input shaft inputs the angular velocity ω1; the angular velocity ω3 of the output shaft is: when R2 / R1 and R4 / R3 are close, the value is very small and the deceleration ratio is very large; even when R2 / R1 - R4 / R3 = 0, an infinite deceleration ratio is obtained.

Claims

1. A balanced differential planetary gear speed reducer, the structure of which includes: It includes a set of planetary gears E on the input side, a set of planetary gears F on the output side, a planet carrier, a double sun gear, a double internal gear ring, and a housing; The integrated structure of the double sun gear includes an input sun shaft, sun gear A, sun gear B. The integrated structure of the double internal gear ring and the housing includes that gear ring C and gear ring D are machined on the inner side of the same cylinder; a support shaft is installed on the support disk of the planet carrier; Structural details: The input sun shaft rotates synchronously meshing with sun gear A and sun gear B; Gear ring C and gear ring D are coaxially machined on the inner side of the cylinder; Principle of operation: When the pitch circle radius of the input end sun gear is R1; the gear ring radius is R2; the pitch circle radius of the output end sun gear is R3; the gear ring radius is R4; the rotational speed of the input sun shaft is (angular velocity) ω1; then, the rotational speed of the gear ring ω2 = (R1 / R2) x ω1; then: The revolution speed of the output end planet carrier: ω3 = ω2(ω1 / ω2 - R4 / R3) / (1 + R4 / R3) ω3 = [R2 / R1(R2 / R1 - R4 / R3) / (1 + R4 / R3)]ω1 Therefore, when the input shaft inputs an angular velocity ω1; the angular velocity ω3 of the output shaft is such that when R2 / R1 and R4 / R3 are close, the value is very small and the reduction ratio is very large; even when approaching R2 / R1 - R4 / R3 = 0, an infinite reduction ratio is obtained; Its characteristics lie in that: The technical implementation elements include a set of input side planetary gears, a planet carrier and housing, an internal gear ring, a sun gear with an input shaft; a set of output side planetary gears, a planet carrier with an output shaft, an internal gear ring, a sun gear coaxially connected to the input shaft; an input shaft with two double sun gears also serving as sun gear shafts; a cylindrical structure with two double internal gear rings; the input axis, output axis, and internal gear ring axis all coincide; the housing constrains the sun shaft as the input shaft through bearings and constrains the central axis of the planet carrier as the output shaft; the input side sun gear of the double sun gear shaft meshes with the input side planetary gears, the planet carrier of the input side planetary gears is part of the connecting housing, and the input side planetary gears mesh with the input side internal gear ring; the output side sun gear of the double sun gear shaft meshes with the output side planetary gears, the planet carrier of the output side planetary gears serves as the output shaft, and the output side planetary gears mesh with the output side internal gear ring. The number of input and output side planetary gears and output side planetary gears is 3 - 10 respectively.

2. An equalizing differential planetary gear speed reducer according to claim 1, wherein the sun shaft is characterized in that It can be fixed together with the housing, with the internal gear ring as the input shaft.

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