Speed reducer with small tooth difference

Abstract

The invention belongs to the technical field of speed reducers, and particularly relates to a small-tooth-difference speed reducer. Comprising a speed reducer shell and a speed reducer end cover which is arranged on one side of the speed reducer shell and used for sealing the speed reducer shell, a transmission assembly which is matched with the speed reducer shell is arranged in the speed reducer shell, and the transmission assembly comprises an eccentric input shaft, a torque conduction balance wheel, a fixed gear and an output gear meshed with the torque conduction balance wheel; when the eccentric input shaft rotates, the torque transmission balance wheel can be driven to perform cycloid rotation along the fixed wheel, and an outer gear ring on the torque transmission balance wheel performs cycloid rotation along with the torque transmission balance wheel, so that the output gear meshed with the torque transmission balance wheel in a small tooth difference manner is driven to rotate; the tooth profile shapes of the inner gear ring, the outer gear ring, the inner gear ring and the outer gear ring are the same and are all in a double-arc tooth shape, and the reduction ratio of the small tooth difference speed reducer is obtained by subtracting the tooth number of the inner gear ring from the tooth number of the outer gear ring of the torque conduction balance wheel and dividing the tooth number of the fixed gear or the output gear.

Description

Technical Field

[0001] The present invention belongs to the technical field of speed reducers, and particularly refers to a planetary gear speed reducer with small tooth difference. Background Art

[0002] A speed reducer is a device that plays a role in matching speeds and transmitting torques between a prime mover and a working machine or an actuator. Its main purpose is to reduce the speed of the prime mover and simultaneously increase the torque to output the power required by the working machine. Commonly used speed reducers include: traditional speed reducers such as gear speed reducers, worm and worm gear speed reducers, harmonic speed reducers, cycloid pinwheel speed reducers, and planetary gear speed reducers with small tooth difference, etc.

[0003] A planetary gear speed reducer with small tooth difference is a mechanical device that realizes efficient transmission through partial meshing of gears. Its core principle is to achieve the functions of speed reduction and torque increase through a combination of gears with a small number of teeth on the input shaft and the output shaft.

[0004] However, the planetary gear speed reducer with small tooth difference currently on the market has a complex structure. In CN101893063A, a planetary gear speed reducer with small tooth difference is mentioned, which improves the existing internal meshing planetary gear transmission device. The components are supported on the housing through a power output structure, and the gear meshing pair has the characteristics of multi-tooth meshing and double-line contact, improving the load-bearing capacity and lubrication characteristics. However, at least two planetary gears are still required for transmission, multiple sets of gears and gear shafts need to be arranged radially, the structure is relatively complex, the assembly is troublesome, the reduction ratio is very large, and it is difficult to calculate and adjust the reduction ratio.

[0005] Therefore, there is a need for a planetary gear speed reducer with small tooth difference that has a simple structure, can input and output coaxially, is easy to install, and has a long service life. Summary of the Invention

[0006] The purpose of the present invention is to provide a planetary gear speed reducer with small tooth difference that has a simple structure, can input and output coaxially, is easy to install, and has a long service life.

[0007] The purpose of the present invention is achieved as follows:

[0008] A planetary gear speed reducer with small tooth difference, characterized in that it includes a speed reducer housing and a speed reducer end cover provided on one side of the speed reducer housing for closing the speed reducer housing. A transmission assembly that cooperates with each other is provided inside the speed reducer housing. The transmission assembly includes an eccentric input shaft, a torque conduction pendulum wheel, a fixed gear, and an output gear that meshes with the torque conduction pendulum wheel;

[0009] The fixed gear is fixed to the reducer housing or the reducer end cover. An external tooth ring is formed on the fixed gear. The torque transmission pendulum wheel is provided with an internal tooth ring and an external tooth ring with different numbers of teeth. The internal tooth ring is located outside the external tooth ring, and the tooth tips of the internal tooth ring and the external tooth ring are arranged oppositely. The number of teeth of the internal tooth ring of the torque transmission pendulum wheel is greater than the number of teeth of the external tooth ring of the fixed gear, and the two are meshed with a small tooth difference; the eccentric input shaft is rotatably arranged inside the reducer housing, and an eccentric disc is arranged on the outer ring of the eccentric input shaft. An installation hole adapted to the eccentric disc is formed in the center of the torque transmission pendulum wheel, and the eccentric disc is arranged in the installation hole. The rotation of the eccentric input shaft can drive the torque transmission pendulum wheel to perform a cycloidal rotation around the fixed wheel. The output gear is rotatably arranged inside the reducer housing. An internal tooth ring is formed on the output gear. The number of teeth on the internal tooth ring of the output gear is greater than the number of teeth of the external tooth ring of the torque transmission pendulum wheel, and the two are meshed with a small tooth difference; the number of teeth of the fixed gear is the same as the number of teeth of the output gear; when the eccentric input shaft rotates, it can drive the torque transmission pendulum wheel to perform a cycloidal rotation along the fixed wheel, and the external tooth ring on the torque transmission pendulum wheel follows to perform a cycloidal rotation, thereby driving the output gear meshed with it with a small tooth difference to perform a rotational movement; the tooth profiles of the internal tooth ring, the external tooth ring, the internal tooth ring and the external tooth ring are the same, all being double-arc tooth profiles. The reduction ratio of the planetary gear reducer with small tooth difference is the number of teeth of the external tooth ring of the torque transmission pendulum wheel minus the number of teeth of the internal tooth ring divided by the number of teeth of the fixed gear or the output gear.

[0010] Further, an output flange is fixedly connected to the output gear. A transmission part is convexly formed on the output flange. A plurality of transmission holes are formed in the transmission part. A transmission port is formed in the reducer end cover. The reducer can transmit the torque to an external component through the output flange.

[0011] Further, an annular connecting part is formed on one side of the fixed gear. A plurality of connecting holes are formed in the annular connecting part. A plurality of connecting ports are formed in the reducer end cover. The fixed gear can be connected to the reducer end cover through a screw.

[0012] Further, a receiving groove is formed between the internal tooth ring and the external tooth ring of the torque transmission pendulum wheel. Both the output gear and the fixed gear are partially clamped in the receiving groove, and the fixed gear is arranged outside the output gear.

[0013] Further, an input shaft installation hole is formed in the middle of the reducer housing. The eccentric input shaft is rotatably arranged in the input shaft installation hole, and a bearing is arranged between the eccentric input shaft and the input shaft installation hole.

[0014] The outstanding and beneficial technical effects of the present invention compared with the prior art are:

[0015] The planetary gear reducer of the present invention includes a reducer housing and a reducer end cover for accommodating a transmission assembly. The transmission assembly includes an eccentric input shaft, a torque-conducting pendulum wheel, a fixed gear, and an output gear. By varying the number of teeth differences between the gears, an imperfect meshing planetary gear fit is achieved between different gears, thereby achieving a high reduction ratio effect. The gears are tightly fitted together, occupying a small space, enabling the overall volume of the reducer to be made smaller.

[0016] Specifically, the mating method includes a fixed gear fixedly arranged on the reducer end cover. An external tooth ring is formed on the outer circle of the fixed gear, and the number of teeth of the external tooth ring is Z2. An internal tooth ring that forms a planetary gear fit with the fixed gear is formed on the torque-conducting pendulum wheel, and the number of teeth of the internal tooth ring is Z1. An eccentric input shaft for driving the torque-conducting pendulum wheel to perform a cycloidal rotation along the outer tooth ring of the fixed gear is arranged in the middle of the torque-conducting pendulum wheel. When the eccentric input shaft rotates, the torque-conducting pendulum wheel as a whole performs a cycloidal rotation. Correspondingly, the external tooth ring on the torque-conducting pendulum wheel also follows a cycloidal rotation. The number of teeth of the external tooth ring on the torque-conducting pendulum wheel is Z3. An internal tooth ring is formed on the output gear, and the number of teeth of the internal tooth ring is Z4. The output gear forms a planetary gear fit with the external tooth ring on the torque-conducting pendulum wheel. The size order of the number of teeth of each gear is Z1 > Z2 = Z4 > Z3, and both Z2 and Z4 are the intermediate numbers between Z1 and Z3. Thus, when the torque-conducting pendulum wheel performs a cycloidal rotation along the fixed gear, the torque-conducting pendulum wheel can reversely drive the output gear to perform a rotational motion again. By adjusting the number of teeth of each gear, rotational motion input and rotational motion output are achieved without the need to adjust the rotational output back through multiple planetary gears. The structural design is simple, occupying a small space, and can meet the usage requirements of many scenarios. Compared with the cooperation between the flexible gear and the rigid gear of the harmonic gear, the gears in the reducer of the present invention all adopt rigid gears, and there is no need to achieve a planetary gear fit through a deformed tooth ring, with higher structural strength and longer service life. The calculation formula for the reduction ratio is: (Z1 - Z3):Z4, and the reduction ratio calculation is also very simple. Brief Description of the Drawings

[0017] Figure 1 is a structural schematic diagram of the present invention.

[0018] Figure 2 is a front view of the present invention.

[0019] Figure 3 is a side view of the present invention.

[0020] Figure 4 is Figure 3 a cross-sectional view of

[0021] Figure 5 is Figure 2 a cross-sectional view of

[0022] Figure 6 is one of the internal structural schematic diagrams of the present invention.

[0023] Figure 7 It is the second schematic diagram of the internal structure of the present invention.

[0024] Figure 8 It is the schematic diagram of the structure of the eccentric input shaft and the torque conduction pendulum wheel in the present invention.

[0025] Figure 9 It is the cross-sectional view of the eccentric input shaft and the torque conduction pendulum wheel in the present invention.

[0026] Figure 10 It is the schematic diagram of the structure of the fixed gear and the output gear in the present invention.

[0027] Figure 11 It is the front view of the fixed gear and the output gear in the present invention.

[0028] Figure 12 It is the schematic diagram of the structure of the output gear in the present invention.

[0029] Figure 13 It is the exploded view of the present invention.

[0030] The meanings represented by the reference numerals in the figure:

[0031] 1 - Reducer housing; 2 - Reducer end cover; 3 - Eccentric input shaft; 4 - Torque conduction pendulum wheel;

[0032] 5 - Fixed gear; 6 - Output gear; 7 - Outer tooth ring; 8 - Inner gear ring; 9 - Outer gear ring; 10 - Eccentric disc; 11 - Mounting hole; 12 - Inner tooth ring; 13 - Output flange; 14 - Transmission part; 15 - Transmission hole; 16 - Transmission port; 17 - Annular connection part; 18 - Connection hole; 19 - Connection port; 20 - Accommodating groove; 21 - Input shaft mounting hole; 22 - Bearing. Specific embodiments

[0033] The present invention will be further described below in conjunction with specific embodiments:

[0034] A planetary gear reducer is characterized in that it includes a reducer housing and a reducer end cover arranged on one side of the reducer housing for closing the reducer housing, and a transmission assembly is arranged in the reducer housing, and the transmission assembly includes an eccentric input shaft, a torque conduction pendulum wheel, a fixed gear, and an output gear meshing with the torque conduction pendulum wheel;

[0035] The fixed gear is fixed to the reducer housing or the reducer end cover. An external gear ring is formed on the fixed gear. Different numbers of internal gear rings and external gear rings are provided on the torque conduction pendulum wheel. Its internal gear ring is located outside the external gear ring. The tips of the teeth on the internal gear ring and the external gear ring are arranged oppositely. The number of teeth of the internal gear ring of the torque conduction pendulum wheel is greater than that of the external gear ring of the fixed gear, and the two are meshed with a small tooth difference; the eccentric input shaft is rotatably arranged inside the reducer housing, and an eccentric disc is arranged on the outer ring of the eccentric input shaft. An installation hole adapted to the eccentric disc is formed in the center of the torque conduction pendulum wheel, and the eccentric disc is arranged in the installation hole. The rotation of the eccentric input shaft can drive the torque conduction pendulum wheel to perform cycloidal rotation around the fixed wheel. The output gear is rotatably arranged in the reducer housing. An internal gear ring is formed on the output gear. The number of teeth on the internal gear ring of the output gear is greater than that of the external gear ring of the torque conduction pendulum wheel, and the two are meshed with a small tooth difference; the number of teeth of the gear of the fixed gear is the same as that of the output gear; when the eccentric input shaft rotates, it can drive the torque conduction pendulum wheel to perform cycloidal rotation along the fixed wheel, and the external gear ring on the torque conduction pendulum wheel follows to perform cycloidal rotation, thereby driving the output gear meshed with it with a small tooth difference to perform rotational rotation; the tooth profiles of the internal gear ring, the external gear ring, the internal gear ring and the external gear ring are the same, and are all double-arc tooth profiles. Compared with the transmission involute tooth profile, this tooth profile has more meshing teeth, and thus has a stronger load capacity. The double-arc tooth profile does not require side clearance, and the transmission accuracy is greatly improved; the reduction ratio of the planetary gear reducer with small tooth difference is the ratio of the number of teeth of the external gear ring of the torque conduction pendulum wheel minus the number of teeth of the internal gear ring to the number of teeth of the fixed gear or the output gear.

[0036] The planetary gear reducer with small tooth difference of the present invention includes a reducer housing and a reducer end cover for accommodating a transmission component. The transmission component includes an eccentric input shaft, a torque conduction pendulum wheel, a fixed gear and an output gear. By changing the difference in the number of teeth between the gears, an incomplete meshing with a small tooth difference is achieved between different gears, so as to achieve the effect of a high reduction ratio. The cooperation of each gear is tight, and the occupied space is small, so that the overall volume of the reducer can be made smaller.

[0037] The specific cooperation method includes a fixed gear fixedly arranged on the end cover of the reducer. An external tooth ring is formed on the outer ring of the fixed gear, and the number of teeth of the external tooth ring is Z2. An internal tooth ring that is in a differential gear ratio cooperation with the fixed gear is formed on the torque transmission pendulum wheel, and the number of teeth of the internal tooth ring is Z1. An eccentric input shaft for driving the torque transmission pendulum wheel to perform a cycloidal rotation along the external tooth ring of the fixed gear is arranged in the middle of the torque transmission pendulum wheel. When the eccentric input shaft rotates, the torque transmission pendulum wheel as a whole performs a cycloidal rotation. Correspondingly, the external tooth ring on the torque transmission pendulum wheel also follows to perform a cycloidal rotation. The number of teeth of the external tooth ring on the torque transmission pendulum wheel is Z3. An internal tooth ring is formed on the output gear, and the number of teeth of the internal tooth ring is Z4. The output gear is in a differential gear ratio cooperation with the external tooth ring on the torque transmission pendulum wheel. The size order of the number of teeth of each gear is Z1>Z2 = Z4>Z3, and both Z2 and Z4 are the intermediate numbers between Z1 and Z3. Thus, when the torque transmission pendulum wheel performs a cycloidal rotation along the fixed gear, the torque transmission pendulum wheel can reversely drive the output gear to perform a rotational motion again. By adjusting the number of teeth of each gear, rotational motion input and rotational motion output can be achieved without adjusting the rotational output back through multiple planetary gears. The structural design is simple, the occupied space is small, and the use requirements of many scenarios can be met. Compared with the cooperation between the flexible gear and the rigid gear of the harmonic gear, the gears in the reducer of the present invention are all rigid gears, and there is no need to use a deformed tooth ring to achieve a differential gear ratio cooperation, so the structural strength is higher and the service life is longer. The calculation formula for the reduction ratio is: (Z1 - Z3):Z4, and the calculation of the reduction ratio is also very simple.

[0038] As a preferred solution, when the number of teeth Z1 of the internal tooth ring and the number of teeth Z3 of the external tooth ring on the torque transmission pendulum wheel are 31 and 29 respectively, and the number of teeth Z2 of the external tooth ring of the fixed gear and the number of teeth Z4 of the internal tooth ring of the output gear are both 30, the reduction ratio of the reducer is calculated to be 1:15 at this time; when it is necessary to adjust the reduction ratio according to the use scenario, gears with different numbers of teeth can be used. When Z1 and Z3 are 32 and 28 respectively, and Z2 and Z4 are both 30, the reduction ratio is 1:7.5 at this time.

[0039] Preferably, an output flange is fixedly connected to the output gear. A transmission part is convexly formed on the output flange. A plurality of transmission holes are opened on the transmission part. A transmission port is opened on the end cover of the reducer, and the reducer can transmit the torque to an external component through the output flange.

[0040] Preferably, an annular connection part is formed on one side of the fixed gear. A plurality of connection holes are opened on the annular connection part. A plurality of connection ports are opened on the end cover of the reducer, and the fixed gear can be connected to the end cover of the reducer through a screw.

[0041] Preferably, there is a receiving groove between the inner gear ring and the outer gear of the torque-conducting balance wheel. The output gear and the fixed gear are both partially clamped in the receiving groove, and the fixed gear is arranged outside the output gear. While the tooth parts of the output gear and the fixed gear are simultaneously clamped in the receiving groove between the torque-conducting balance wheels, the output gear and the fixed gear are respectively in a small tooth difference fit with the inner gear ring and the outer gear ring on the torque-conducting balance wheel, with high space utilization rate, convenient assembly and not easy to disengage from the meshing.

[0042] Preferably, an input shaft mounting hole is provided in the middle of the reducer housing, the eccentric input shaft is rotatably arranged in the input shaft mounting hole, and a bearing is arranged between the eccentric input shaft and the input shaft mounting hole.

[0043] The above embodiments are only the preferred embodiments of the present invention, and do not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. A small-tooth difference reducer, characterized in that: The reducer comprises a reducer housing and a reducer end cover arranged on one side of the reducer housing for closing the reducer housing, wherein a transmission assembly cooperating with each other is arranged in the reducer housing, and the transmission assembly comprises an eccentric input shaft, a torque transmission balance wheel, a fixed gear, and an output gear meshing with the torque transmission balance wheel; The fixed gear is fixed on the reducer housing or the reducer end cover, and an outer gear ring is formed on the fixed gear. The torque conduction balance wheel is provided with an inner gear ring and an outer gear ring with different numbers of teeth, wherein the inner gear ring is located outside the outer gear ring, and the tooth tips on the inner gear ring and the outer gear ring are arranged opposite to each other. The number of teeth of the inner gear ring of the torque conduction balance wheel is greater than the number of teeth of the outer gear ring of the fixed gear, and the two are meshed with a small tooth difference; the eccentric input shaft is rotatably arranged inside the reducer housing, and the outer ring of the eccentric input shaft is arranged on the eccentric disk. A mounting hole adapted to the eccentric disk is opened at the center of the torque conduction balance wheel, and the eccentric disk is arranged in the mounting hole. The rotation of the eccentric input shaft can drive the torque conduction balance wheel to rotate cycloid around the fixed wheel, and the output The gear rotation is arranged in the reducer housing, and an inner gear ring is formed on the output gear. The number of teeth on the inner gear ring of the output gear is greater than the number of teeth on the outer gear ring of the torque transmission balance wheel, and the two are meshed with a small tooth difference; the number of teeth of the fixed gear is the same as the number of teeth of the output gear; when the eccentric input shaft rotates, it can drive the torque transmission balance wheel to rotate cycloid along the fixed wheel, and the outer gear ring on the torque transmission balance wheel follows the cycloid rotation, thereby driving the output gear meshed with the small tooth difference to rotate, and the tooth profile shapes of the inner gear ring, outer gear ring, inner gear ring and outer gear ring are the same, all of which are double arc tooth shapes, and the reduction ratio of the small tooth difference reducer is the number of teeth of the outer gear ring of the torque transmission balance wheel minus the number of teeth of the inner gear ring divided by the number of teeth of the fixed gear or the output gear.

2. A small-tooth-difference reducer according to claim 1, characterized in that: The output gear is fixedly connected with an output flange, the output flange is protruding with a transmission part, the transmission part is provided with a plurality of transmission holes, the reducer end cover is provided with a transmission port, and the reducer can transmit the torque to the external component through the output flange.

3. The small-tooth-difference reducer according to claim 1, characterized in that: An annular connecting portion is formed on one side of the fixed gear, a plurality of connecting holes are formed on the annular connecting portion, a plurality of connecting ports are formed on the reducer end cover, and the fixed gear can be connected to the reducer end cover through a screw.

4. A small-tooth-difference reducer according to any one of claims 1 to 3, characterized in that: An accommodating groove is provided between the inner gear ring and the outer gear ring of the torque transmission balance wheel, and the output gear and the fixed gear are partially stuck in the accommodating groove, and the fixed gear is arranged on the outer side of the output gear.

5. A small-tooth-difference reducer according to claim 4, characterized in that: An input shaft mounting hole is provided in the middle of the reducer housing, the eccentric input shaft is rotatably arranged in the input shaft mounting hole, and a bearing is arranged between the eccentric input shaft and the input shaft mounting hole.

Images