Two-stage planetary reducer and joint module thereof

Abstract

The utility model discloses a two-stage planetary reducer and a joint module thereof. The two-stage planetary reducer comprises a planetary gear ring, a first-stage planet carrier, a first-stage planet wheel, a second-stage planet carrier, a second-stage planet wheel, a first-stage sun wheel shaft, a second-stage sun wheel shaft and an output disc. The speed reducer provided by the utility model adopts two-stage planetary speed reduction, so that a larger speed reduction ratio can be realized in a limited space, and the output efficiency of a joint motor is more effectively improved. The integration degree of the robot joint module can be remarkably improved, elements such as a controller, an encoder, a brake speed reducer and the like can be integrated, and integration manufacturers can conveniently and rapidly complete robot product development. According to the speed reducer, redundant connecting structures are reduced, input and output are integrated on one shaft, namely the first-stage sun wheel shaft, the stability of torque transmission is greatly improved, and the torque density and the power density of the speed reducer are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of robots, in particular to a two-stage planetary reducer and a joint module thereof. Background Art

[0002] Planetary reducer is a reducer with three planetary gears rotating around a sun gear. With the rapid development of the planetary reducer industry, more and more industries and different companies have applied planetary reducers. The main products are planetary gear reducers; helical gear-spiral bevel gear reducers; spiral bevel gear steering boxes; hardened helical gear reducers; parallel shaft helical gear reducers; helical gear-worm reducers; hardened industrial gearboxes; continuously variable speed machines; worm gear reducers and various series of non-standard reducers. It is suitable for industrial sectors such as lifting and transportation, engineering machinery, metallurgy, mining, petrochemicals, construction machinery, light industry and textiles, medical equipment, instruments and meters, automobiles, ships, weapons and aerospace.

[0003] Existing robot joint modules generally have low power density and torque density, and are mainly assembled by robot integrators using standard reducers and servo motors. Such a design cannot meet the robot's requirements for torque density and power density, and also causes the problem of too low system integration, causing a certain degree of trouble in system stability and maintainability.

[0004] In the past, robot joints were made of standard parts, which could not meet the requirements of high integration, and could not provide sufficient torque density and power density to guarantee the performance of the robot. This situation would cause the robot products of integrated manufacturers to have low cycle speed, poor maintainability, poor load capacity, etc. In some complex applications, they could not provide sufficient performance.

[0005] Moreover, the prior art generally uses a single-stage reducer, which cannot achieve a larger reduction ratio in a limited space and has relatively limited applications. Utility Model Content

[0006] The utility model aims to overcome at least one defect of the above-mentioned prior art and provide a two-stage planetary reducer and a joint module thereof, so as to achieve the purposes of high integration, small occupied space and volume, and large reduction ratio.

[0007] Specifically, the utility model provides a two-stage planetary reducer, comprising a planetary gear ring, a primary planet carrier, a primary planetary gear, a secondary planet carrier, a secondary planetary gear, a primary sun gear shaft, a secondary sun gear shaft and an output disk; there are multiple primary planetary gears and secondary planetary gears; the primary planetary gear is arranged on the primary planet carrier; the secondary planetary gear is arranged on the secondary planet carrier; one end of the primary sun gear shaft is externally connected to a motor; the other end passes through the central axis of the primary planet carrier and is fixed; one end of the secondary sun gear shaft passes through the secondary planet carrier and is fixed, and the other end is connected to the output disk; the primary sun gear shaft and the secondary sun gear shaft are on the same axis; the primary sun gear shaft and the secondary sun gear shaft are linear shafts with serrated sides; the primary sun gear shaft is meshed with an inner ring composed of multiple primary planetary gears; the secondary sun gear shaft is meshed with an inner ring composed of multiple secondary planetary gears; the inner wall of the planetary gear ring is meshed with an outer ring composed of multiple primary planetary gears and an outer ring composed of multiple secondary planetary gears.

[0008] In the present invention, the reducer adopts a two-stage planetary reduction, which can achieve a larger reduction ratio in a limited space and more effectively improve the output efficiency of the joint motor. And a major invention point of the present invention is that the sun wheel of the present invention integrates the functions of the rotating shaft and the rotating wheel; at the same time, the first-level sun wheel shaft also integrates the function of the motor rotating shaft, and the motor shaft of the external motor is the sun wheel in this application, and the motor drives the first-level sun wheel shaft to rotate, and then engages the first-level planetary wheel to rotate; therefore, the present invention adopts a combination of a brushless motor and a planetary reducer, integrating the two on the same rotating shaft, and the sun wheel of the planetary reducer is integrated on the motor rotor, which improves the torque density and power density of the motor output;

[0009] Furthermore, the two-stage planetary reducer of the utility model also includes a crossed roller bearing; the outer ring of the crossed roller bearing is connected to the planetary gear ring; and the inner ring is connected to the output disc.

[0010] The cross roller bearing is used to connect the planetary gear ring and the output disc to ensure concentricity. The cross roller bearing can provide radial and axial support at the same time. For robot applications, the shaft system design outside the robot arm can be omitted, which greatly improves the system integration.

[0011] Furthermore, the two-stage planetary reducer of the utility model also includes a flange bearing; the inner end of the flange bearing fits the planetary gear ring, and the outer end is connected to the output disk, and the cross roller bearing is sleeved on the outer ring of the flange bearing.

[0012] The flange bearing can effectively prevent the axial movement of the planetary gear and avoid wear of the aluminum parts.

[0013] Furthermore, the first-stage planetary carrier and the second-stage planetary carrier are stacked, the first-stage planetary carrier is cylindrical, has multiple first through holes at both ends, and planetary gear avoidance holes on the side; the first-stage planetary gear is provided with a first stud and a first nut, and the first-stage planetary gear is fixed to the first through hole by the first stud and the first nut.

[0014] More specifically, there are three first-stage planetary wheels and three second-stage planetary wheels, there are three first through holes, the first-stage planet carrier is hollow, and planetary wheel avoidance holes are provided on the side, which improves the stability of the first-stage planet carrier and does not affect the rotation process of the first-stage planetary wheels.

[0015] Furthermore, the secondary planetary carrier is disc-shaped, and is provided with a plurality of second through holes for fixing to the secondary planetary gear; the secondary planetary gear is provided with a second stud and a second nut, and the secondary planetary gear is fixed to the second through hole by the second stud and the second nut; and the side of the secondary planetary carrier facing the output disc is provided with a plurality of bosses for connecting the output disc.

[0016] The diameter of the secondary planet carrier is the same as that of the primary planet carrier. The height of the boss is equal to the height after the secondary planet gear is installed. The boss is fixedly connected to the output disc by screws. The primary planet gear and the secondary planet gear are integrated on the inner side of the planetary gear ring and meshed with it.

[0017] Furthermore, the side edges of the convex columns are in the shape of an inwardly concave arc, and the secondary planetary gear is embedded between the convex columns.

[0018] The design of the convex column can increase the stability of the secondary planetary carrier. In order not to affect the rotation of the secondary planetary gear, the side of the convex column designed by the utility model has an arc-shaped concave. Specifically, there are three convex columns, which are evenly distributed on the secondary planetary carrier, and spaces for installing the secondary planetary gears are formed between the convex columns, thereby avoiding the influence of airflows between each other and improving the stability of the rotation of the secondary planetary gear.

[0019] The utility model also provides a joint module, comprising the above-mentioned two-stage planetary reducer.

[0020] More preferably, the joint module of the utility model further includes a control panel, a motor stator, and a motor rotor; the primary sun gear shaft passes through the motor stator and the motor rotor, one end of which is connected to the motor stator, and the other end of which is connected to the secondary sun gear shaft. In the utility model, the primary sun gear shaft is both a motor shaft and a connecting and supporting shaft for connecting the primary planetary gear, which reduces the use of multiple shafts and improves overall stability.

[0021] Furthermore, the joint module of the utility model also includes a brake arranged on the motor stator and a detection magnet arranged on the primary sun gear shaft.

[0022] The holding brake is used for braking during the operation of the motor; the detection magnet cooperates with the motor rotor and the motor stator, that is, the Hall element in the motor stator to detect the rotation state of the motor. In the utility model, the encoder sensor element, that is, the detection magnet, is integrated at the rear end of the motor, which can provide the control board with output angle-related information. In addition, the brake, that is, the brake winding and brake pin of the electromagnetic brake, cooperate with the groove between the middle magnets of the motor rotor to form an integrated locking brake. When the robot needs to stop or standby and transport, the output position of the joint motor can be kept stable without the time-limit problem caused by the encoder backup battery used in similar product designs. The next time the joint is powered on, the system can still use the joint motor position recorded when it was shut down last time.

[0023] More preferably, the joint module in another embodiment of the utility model includes the above-mentioned two-stage planetary reducer and also includes a fixed seat, one end side of the fixed seat is fixed to the motor stator; and the other end is connected to the cross roller bearing.

[0024] Different from the traditional design, in this design, the overall shell of the joint motor consists of two parts: one is the whole shell of the output end, which can also provide fixed installation; the other is the integrated fixing seat, which integrates the fixing seat of the motor winding and the shell of the reducer; these two structural parts are fastened and locked by special shell locking nuts and screws, and cooperate with the anti-rotation screws to achieve axial integration and radial anti-rotation of the front and rear covers at the same time. Further providing the integrated design of the system can also greatly improve the power density and torque density of the joint module.

[0025] Compared with the prior art, the beneficial effects of the utility model are:

[0026] In the utility model, the reducer adopts a two-stage planetary reduction, which can achieve a larger reduction ratio in a limited space and more effectively improve the output efficiency of the joint motor.

[0027] The utility model can significantly improve the integration of the robot joint module, and can integrate components such as controller encoder brake reducer, so as to facilitate integration manufacturers to quickly complete robot product development.

[0028] The utility model reduces redundant connection structures, and the input and output are integrated on one shaft, namely, the primary sun gear shaft, which greatly improves the stability of torque transmission and the torque density and power density of the reducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the explosion structure of the two-stage planetary reducer of the utility model.

[0030] Figure 2This is a schematic diagram of the assembly structure of the two-stage planetary reducer of the utility model.

[0031] Figure 3 It is a structural schematic diagram of the two-stage planetary reducer of the utility model with some parts omitted.

[0032] Figure 4 It is a three-dimensional structural schematic diagram of the secondary planetary carrier of the utility model.

[0033] Figure 5 It is a schematic diagram of the assembled three-dimensional structure of the joint module of the utility model.

[0034] Figure 6 It is a schematic diagram of the exploded structure of the joint module of the utility model.

[0035] Figure 7 It is a longitudinal cross-sectional schematic diagram of the joint module of the utility model. DETAILED DESCRIPTION

[0036] The drawings in the embodiments provide a more detailed description of the technical solutions in the embodiments of the utility model. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of the utility model, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the utility model, and should not be construed as limitations on the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model. The embodiments of the utility model are described in detail below in conjunction with the drawings.

[0037] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0039] Example 1

[0040] This embodiment provides a two-stage planetary reducer, combined with Figures 1-2 As shown, it includes a planetary ring gear 1, a primary planet carrier 2, three sets of primary planetary gears 3, a secondary planet carrier 4, three sets of secondary planetary gears 5, a primary sun gear shaft 6, a secondary sun gear shaft 7, a cross roller bearing 8, a flange bearing 9 and an output disc 10; there are three primary planetary gears 3 and two secondary planetary gears 5; the three primary planetary gears 3 are evenly arranged on the primary planet carrier 2; the three secondary planetary gears 5 are evenly arranged on the secondary planet carrier 4; one end of the primary sun gear shaft 6 is externally connected to the motor; the other end passes through the central axis of the primary planet carrier 2 and is fixed; the secondary One end of the sun gear shaft 7 is fixed through the secondary planet carrier 4, and the other end is connected to the output disk 10; the primary sun gear shaft 6 and the secondary sun gear shaft 7 are on the same axis; the primary sun gear shaft 6 and the secondary sun gear shaft 7 are linear shafts with serrated sides; the primary sun gear shaft 6 is meshed with the inner ring composed of the three primary planetary gears 3; the secondary sun gear shaft 7 is meshed with the inner ring composed of the three secondary planetary gears 5; the inner wall of the planetary gear ring 1 is meshed with the outer ring composed of the three primary planetary gears 3 and the outer ring composed of the three secondary planetary gears 5 at the same time. The outer ring of the cross roller bearing 8 is connected to the planetary gear ring 1; the inner ring is connected to the output disk 10. The inner end of the flange bearing 9 is attached to the planetary gear ring 1, and the outer end is connected to the output disk 10, and the cross roller bearing 8 is sleeved on the outer ring of the flange bearing 9.

[0041] The primary sun gear shaft 6 is driven by a motor to rotate, and the first deceleration is achieved through three primary planetary gears 3; the primary planetary gear 3 further drives the planetary ring 1 to rotate, and then drives the secondary planetary gear 5 to rotate, thereby realizing the rotation of the secondary sun gear shaft 7, and then drives the output disc 10 to rotate. The secondary planetary gear 5 achieves two decelerations.

[0042] Combination Figure 1 and Figure 3 As shown, the primary planet carrier 2 and the secondary planet carrier 4 are stacked, the primary planet carrier 2 is cylindrical, with three first through holes 11 at both ends and a planetary gear avoidance hole 12 at the side; the primary planetary gear 3 is provided with a first stud 13 and a first nut 14, and the primary planetary gear 3 is fixed to the first through hole 11 by the first stud 13 and the first nut 14. The primary planet carrier 2 is hollow, and the planetary gear avoidance hole 12 is provided on the side, which improves the stability of the primary planet carrier 2 and does not affect the rotation process of the primary planetary gear 3.

[0043] Combination Figure 1 and Figure 3As shown, the secondary planet carrier 4 is in the shape of a disc, and is provided with three second through holes 15 for fixing with the secondary planetary gear 5; the secondary planetary gear 5 is provided with a second stud 16 and a second nut 17, and the secondary planetary gear 5 is fixed to the second through hole 15 by the second stud 16 and the second nut 17; the secondary planet carrier 4 is provided with three bosses 18 for connecting the output disk 10 on one side facing the output disk 10. The secondary planet carrier 4 has the same diameter as the primary planet carrier 2. The height of the boss 18 is the same as the height after the secondary planetary gear 5 is installed. The boss 18 is fixedly connected to the output disk 10 by screws. The primary planetary gear 3 and the secondary planetary gear 5 are integrated on the inner side of the planetary gear ring 1 and meshed therewith. The secondary planet carrier 4 also serves as a limiter for the cross roller bearing 8.

[0044] Combination Figure 4 As shown, the side of the convex column 18 is in the shape of a concave arc, and the secondary planetary gear 5 is embedded between the convex columns 18 .

[0045] The side of the convex column 18 has an arc-shaped concave 100. Specifically, there are three convex columns 18, which are evenly distributed on the secondary planetary carrier 4, and spaces for installing the secondary planetary gears 5 are formed between the convex columns 18, thereby avoiding the influence of airflow between each other and improving the rotation stability of the secondary planetary gears 5.

[0046] Example 2

[0047] like Figure 5 As shown, the utility model also provides a joint module 200, including the above-mentioned two-stage planetary reducer 300.

[0048] Specific, combined Figures 6-7 As shown, the joint module of the utility model also includes a control board 19, a motor stator 20, a motor rotor 21, a brake 22 and a detection magnet 23; the primary sun gear shaft 6 passes through the motor stator 20 and the motor rotor 21, one end is connected to the motor stator 20, and the other end is connected to the secondary sun gear shaft 7; the brake 22 is arranged on the motor stator 20, and the detection magnet 23 is sleeved on one end of the primary sun gear shaft 6 close to the control board 19. The joint module of the utility model also includes a fixed seat 24 and a plurality of bearings 25 for fixing the primary sun gear shaft 6 and the secondary sun gear shaft 7, and the model of the bearing 25 is MR148 bearing. One end side of the fixed seat 24 is fixed to the motor stator 20; the other end is connected to the cross roller bearing 8.

[0049] The above embodiments are only used to illustrate the technical solution of the utility model and are not intended to limit it. Although the utility model is described in detail with reference to the above preferred embodiments, those skilled in the art should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model. Those skilled in the art can also make other changes within the spirit of the utility model and apply them to the design of the utility model, as long as they do not deviate from the technical effects of the utility model. These changes made according to the spirit of the utility model should be included in the scope of protection claimed by the utility model.

Claims

1. A two-stage planetary reducer, characterized in that: It comprises a planetary ring gear (1), a primary planet carrier (2), a primary planetary gear (3), a secondary planet carrier (4), a secondary planetary gear (5), a primary sun gear shaft (6), a secondary sun gear shaft (7) and an output disc (10); the primary planetary gear (3) and the secondary planetary gear (5) are multiple; The first-stage planetary gear (3) is arranged on the first-stage planetary carrier (2); the second-stage planetary gear (5) is arranged on the second-stage planetary carrier (4); One end of the first-stage sun gear shaft (6) is externally connected to a motor; the other end passes through the center axis of the first-stage planet carrier (2) and is fixed; One end of the secondary sun gear shaft (7) passes through the secondary planet carrier (4) for fixing, and the other end is connected to the output disk (10); the primary sun gear shaft (6) and the secondary sun gear shaft (7) are on the same axis; the primary sun gear shaft (6) and the secondary sun gear shaft (7) are linear shafts with sawtooth-shaped sides; the primary sun gear shaft (6) is meshed with an inner ring composed of a plurality of primary planet gears (3); the secondary sun gear shaft (7) is meshed with an inner ring composed of a plurality of secondary planet gears (5); The inner wall of the planetary gear ring (1) is meshed with an outer ring composed of a plurality of primary planetary gears (3) and an outer ring composed of a plurality of secondary planetary gears (5).

2. The two-stage planetary reducer according to claim 1, characterized in that: It also includes a cross roller bearing (8); the outer ring of the cross roller bearing (8) is connected to the planetary gear ring (1); and the inner ring is connected to the output disc (10).

3. The two-stage planetary reducer according to claim 2, characterized in that: It also includes a flange bearing (9); the inner end of the flange bearing (9) is in contact with the planetary gear ring (1), and the outer end is connected to the output disk (10); the cross roller bearing (8) is sleeved on the outer ring of the flange bearing (9).

4. The two-stage planetary reducer according to claim 1, characterized in that: The first-stage planet carrier (2) and the second-stage planet carrier (4) are stacked; the first-stage planet carrier (2) is cylindrical, with a plurality of first through holes (11) at both ends and a planetary gear avoidance hole (12) at the side; the first-stage planetary gear (3) is provided with a first stud (13) and a first nut (14); the first-stage planetary gear (3) is fixed to the first through hole (11) by means of the first stud (13) and the first nut (14).

5. The two-stage planetary reducer according to claim 1, characterized in that: The secondary planet carrier (4) is in the shape of a disk, and is provided with a plurality of second through holes (15) for fixing with the secondary planetary gear (5); the secondary planetary gear (5) is provided with a second stud (16) and a second nut (17), and the secondary planetary gear (5) is fixed to the second through hole (15) via the second stud (16) and the second nut (17); and a plurality of bosses (18) for connecting with the output disc (10) are provided on a side of the secondary planet carrier (4) facing the output disc (10).

6. The two-stage planetary reducer according to claim 5, characterized in that: The side edges of the convex columns (18) are in the shape of an inwardly concave arc, and the secondary planetary gear (5) is embedded between the convex columns (18).

7. A joint module, characterized in that: It comprises the two-stage planetary reducer as described in any one of claims 1 to 6.

8. The joint module according to claim 7, characterized in that: It also includes a control panel (19), a motor stator (20), and a motor rotor (21); the first-stage sun gear shaft (6) passes through the motor stator (20) and the motor rotor (21), one end of which is connected to the motor stator (20), and the other end of which is connected to the second-stage sun gear shaft (7).

9. The joint module according to claim 8, characterized in that: It also includes a brake (22) arranged on the motor stator (20) and a detection magnet (23) arranged on the primary sun gear shaft (6).

10. A joint module, characterized in that: The two-stage planetary reducer comprises the two-stage planetary reducer as claimed in any one of claims 2 to 3, and further comprises a fixing seat (24) and a motor stator (20), wherein one end side edge of the fixing seat (24) is fixed to the motor stator (20); The other end is connected to the cross roller bearing (8).

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