Speed reducers and robots that use them
By setting a counterweight on the eccentric shaft in the reducer, the eccentric force during gear revolution is counteracted, the dynamic balance problem of the reducer is solved, and more stable transmission and higher gear meshing efficiency are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU HUIXING POWER TECHNOLOGY CO LTD
- Filing Date
- 2025-09-11
- Publication Date
- 2026-06-30
AI Technical Summary
Existing speed reducers have dynamic balance problems during operation, especially due to the centrifugal force of the gear structure, which makes them unable to operate stably.
A counterweight is installed on an eccentric shaft in the reducer. The eccentric force generated by its revolution is used to counteract the eccentric force generated by the revolution of the first external gear and the second external gear, thereby achieving dynamic balance.
By designing a counterweight, the reducer achieves dynamic balance, improving transmission stability and gear meshing smoothness, while reducing cost and space occupation.
Smart Images
Figure CN224433286U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of transmission technology, specifically relating to transmission with gears, and more particularly to a speed reducer and a robot using the speed reducer. Background Technology
[0002] A speed reducer is an independent, closed transmission device between the prime mover and the driven machine, used to reduce speed and increase torque to meet working requirements.
[0003] For example, the prototype reducer based on a double star wheel, patent number "CN217108044U", has a large centrifugal force in its gear structure when rotating, which makes the reducer unable to achieve dynamic balance.
[0004] Therefore, how to solve the dynamic balance problem of the reducer during operation is a problem that urgently needs to be solved by those skilled in the art.
[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of the present application concept, and therefore, the above description is not considered to constitute prior art information. Utility Model Content
[0006] This disclosure provides at least one speed reducer and a robot using the speed reducer.
[0007] In a first aspect, embodiments of this disclosure provide a speed reducer, comprising: an eccentric shaft, including: an input eccentric portion; an external gear set sleeved on the eccentric portion, including: a first external gear and a second external gear; a fixed internal gear ring sleeved on the periphery of the external gear set and meshing with the first external gear; and an output internal gear rotatably disposed within the fixed internal gear ring and meshing with the second external gear; wherein the input portion, the fixed internal gear ring, and the output internal gear are coaxially arranged, and at least one counterweight is sleeved on the eccentric portion.
[0008] In one optional embodiment, the eccentricity 'a' between the eccentric portion and the input portion ranges from 0 mm. <a≤2mm。
[0009] In one alternative implementation, the input section is hollow.
[0010] In one alternative embodiment, the first external gear and the second external gear are coaxially arranged and axially connected by a locating pin to rotate synchronously.
[0011] In one optional embodiment, the eccentric portion is provided with an irregularly shaped notch; the counterweight is provided with an irregularly shaped protrusion that matches the irregularly shaped notch.
[0012] In one optional embodiment, a needle roller bearing is fitted onto the eccentric portion; both the first external gear and the second external gear are fitted onto the needle roller bearing.
[0013] In one optional embodiment, an output flange is connected to the lower surface of the output internal gear; the output internal gear and the output flange are coaxially arranged and axially connected by a locating pin to rotate synchronously.
[0014] In one alternative implementation, there are two counterweights, located above and below the external gear assembly, respectively.
[0015] In one optional embodiment, a first thin-walled bearing is disposed on the outside of the output internal gear; the output internal gear is rotatably connected to the fixed internal gear ring via the first thin-walled bearing; a crossed roller bearing is disposed on the outside of the output flange; the output flange is rotatably connected to the fixed internal gear ring via the crossed roller bearing; one end of the eccentric shaft extends into the output flange; a second thin-walled bearing is sleeved on the end of the eccentric shaft; the second thin-walled bearing is rotatably connected to the output flange; the inner wall of the fixed internal gear ring is provided with a first internal gear portion and a mounting portion; the first external gear meshes with the first internal gear portion; both the first thin-walled bearing and the crossed roller bearing are connected to the mounting portion.
[0016] Secondly, embodiments of this disclosure also provide a robot, including: a joint having a reducer applied thereon; the joint includes: a shoulder joint or forearm joint or wrist joint or knee joint or ankle joint or hip joint or trunk joint.
[0017] The beneficial effect of this utility model is that the reducer and the robot using the reducer can achieve dynamic balance by setting a counterweight, so that the eccentric force generated by the rotation of the counterweight can counteract the eccentric force generated by the rotation of the first external gear and the second external gear.
[0018] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description and the accompanying drawings.
[0019] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description
[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of the structure of a speed reducer provided in an embodiment of the present disclosure;
[0022] Figure 2 This is a schematic diagram of the structure of an eccentric shaft provided in an embodiment of the present disclosure;
[0023] Figure 3 This is a schematic diagram of the installation structure of an external gear set provided in an embodiment of the present disclosure;
[0024] Figure 4 This is a cross-sectional structural schematic diagram of a speed reducer provided in an embodiment of the present disclosure;
[0025] Figure 5 A schematic diagram of the installation structure of a counterweight block provided in an embodiment of this disclosure;
[0026] Figure 6 A schematic diagram of eccentricity provided for an embodiment of this disclosure;
[0027] Figure 7 This is a top view of a speed reducer provided in an embodiment of the present disclosure;
[0028] Figure 8 This is an exploded structural diagram of a speed reducer provided in an embodiment of this disclosure.
[0029] In the picture:
[0030] Eccentric shaft 1, input section 10, eccentric section 11, irregular notch 111, counterweight 12, irregular protrusion 121, second thin-walled bearing 13;
[0031] External gear set 2, first external gear 21, second external gear 22, needle roller bearing 23, locating pin 24;
[0032] Fixed internal gear ring 3, first internal gear part 31, mounting part 32;
[0033] Output internal gear 4, output flange 41, first thin-walled bearing 42, crossed roller bearing 43;
[0034] Eccentricity a. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0036] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the figures, the thickness of parts may be exaggerated or reduced for the purpose of effectively depicting the technical content.
[0037] The following detailed description, with reference to the accompanying drawings, describes some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.
[0038] like Figure 1 As shown, at least one embodiment provides a speed reducer, including: an eccentric shaft 1, an external gear set 2, a fixed internal gear ring 3, and an output internal gear 4.
[0039] Specifically, such as Figure 2 As shown, the eccentric shaft 1 includes an input section 10 and an eccentric section 11; wherein, the input section 10 is used to connect to a driver, and the eccentric section 11 is not coaxial with the input section 10, that is, when the input section 10 rotates, the eccentric section 11 revolves around the input section 10.
[0040] Specifically, such as Figure 3 As shown, the external gear set 2 includes: a first external gear 21 and a second external gear 22 connected to the first external gear 21; wherein, the first external gear 21 and the second external gear 22 are both sleeved on the eccentric part 11 to follow the eccentric part 11 in revolving around the input part 10.
[0041] Specifically, such as Figures 1 to 3 As shown, the fixed internal gear ring 3 is sleeved on the periphery of the external gear set 2 and meshes with the first external gear 21; that is, while the first external gear 21 revolves around the input part 10, it rotates by meshing with the fixed internal gear ring 3.
[0042] Specifically, such as Figure 4 As shown, the output internal gear 4 is rotatably mounted inside the fixed internal gear ring 3 and meshes with the second external gear 22; that is, the output internal gear 4 rotates under the drive of the rotation and revolution of the second external gear 22, thereby driving the connected components to perform corresponding actions.
[0043] Since the input section 10, the fixed internal gear ring 3 and the output internal gear 4 are coaxially arranged, and the eccentric section 11 is not coaxially arranged with the input section 10, the first external gear 21 and the second external gear 22 will generate a large eccentric force when the input section 10 rotates, which affects the dynamic balance of the reducer.
[0044] To address the above problems, in some embodiments, such as Figure 5 As shown, at least one counterweight 12 is fitted onto the eccentric part 11.
[0045] Specifically, the eccentric part 11 is biased to the left, and the counterweight 12 is biased to the right. The counterweight 12 revolves with the eccentric part 11.
[0046] In this embodiment, by setting a counterweight 12, the eccentric force generated by the rotation of the counterweight 12 is used to counteract the eccentric force generated when the first external gear 21 and the second external gear 22 rotate, thereby achieving dynamic balance of the reducer.
[0047] In some embodiments, such as Figure 5 As shown, there are two counterweights 12, located above and below the external gear set 2, respectively.
[0048] In this embodiment, using two counterweights 12 can make the eccentric force generated by the counterweights 12 more evenly distributed.
[0049] In some embodiments, such as Figure 6 As shown, the eccentricity a between the eccentric part 11 and the input part 10 ranges from 0 mm. <a≤2mm。
[0050] Optionally, the diameter of this reducer is 52mm and the eccentricity a is 0.8mm.
[0051] In some embodiments, such as Figure 6 As shown, the input section 10 is hollow.
[0052] In this embodiment, the hollow structure facilitates the wiring of the robot joints.
[0053] In some embodiments, the tooth difference between the first external gear 21 and the fixed internal gear ring 3 ranges from 1 to 10.
[0054] In one application scenario, the reducer has a diameter range of 40mm-55mm, and can achieve a reduction ratio of over 200 or even 1000 even with non-minimal modules (0.2mm, 0.1mm).
[0055] In this embodiment, the reducer optimizes the stress distribution of the tooth profile, increasing the load-bearing capacity and service life, while also making the gear meshing smoother while ensuring precise transmission. At the same time, the dynamic balance compensation structure of this reducer is low in cost, occupies little space, and is simple and reliable.
[0056] In some embodiments, such as Figure 5 As shown, the first external gear 21 and the second external gear 22 are coaxially arranged and axially connected by a locating pin to rotate synchronously.
[0057] In this embodiment, the first external gear 21 and the second external gear 22 are fixedly connected together by axial interference fit through positioning pin 24, thereby achieving synchronous rotation.
[0058] In some embodiments, such as Figure 5 As shown, a needle roller bearing 23 is fitted on the eccentric part 11; the first external gear 21 and the second external gear 22 are both fitted on the needle roller bearing 23.
[0059] In this embodiment, the presence of the needle roller bearing 23 reduces the resistance experienced by the first external gear 21 and the second external gear 22 during rotation.
[0060] In some embodiments, the input part 10 is optionally a hollow rotating shaft, and the eccentric part 11 is a cylindrical protrusion on the hollow rotating shaft, the cylindrical protrusion being arranged along the axial direction of the hollow rotating shaft.
[0061] In some embodiments, such as Figure 2 As shown, an irregularly shaped notch 111 is provided on the eccentric part 11, which is used to assemble the counterweight block 12.
[0062] In some embodiments, such as Figure 7 As shown, the counterweight 12 is provided with an irregular protrusion 121 that matches the irregular notch 111; the counterweight 12 is inserted into the irregular notch 111 through the irregular protrusion 121, so that the counterweight 12 rotates synchronously with the eccentric part 11.
[0063] In some embodiments, such as Figure 8 As shown, the lower surface of the output internal gear 4 is connected to the output flange 41; the output internal gear 4 and the output flange 41 are coaxially arranged and are axially connected by a locating pin to rotate synchronously.
[0064] In some embodiments, such as Figure 8 As shown, a first thin-walled bearing 42 is provided on the outside of the output internal gear 4; a crossed roller bearing 43 is provided on the outside of the output flange 41.
[0065] Specifically, the output internal gear 4 is rotatably connected to the fixed internal gear ring 3 via the first thin-walled bearing 42; the output flange 41 is rotatably connected to the fixed internal gear ring 3 via the crossed roller bearing 43.
[0066] In some embodiments, such as Figure 8 As shown, the inner wall of the fixed internal gear ring 3 is provided with a first internal gear part 31 and a mounting part 32; the first external gear 21 meshes with the first internal gear part 31; the first thin-walled bearing 42 and the crossed roller bearing 43 are both connected to the mounting part 32.
[0067] In this embodiment, the output internal gear 4 and the output flange 41 are fixedly connected. Optionally, they are fixedly connected together by a locating pin and an axial interference fit. The function of the first thin-walled bearing 42 and the crossed roller bearing 43 is to enable the output internal gear 4 and the output flange 41 to rotate stably in the fixed internal gear ring 3.
[0068] In some embodiments, such as Figure 4 As shown, one end of the eccentric shaft 1 extends into the output flange 41; a second thin-walled bearing 13 is sleeved on the end of the eccentric shaft 1; the second thin-walled bearing 13 is rotatably connected to the output flange 41.
[0069] In this embodiment, the function of the second thin-walled bearing 13 is to enable the eccentric shaft 1 to rotate stably.
[0070] At least one embodiment also provides a robot including: an articulated joint on which a speed reducer is applied.
[0071] For details on the specific structure and implementation process of the speed reducer, please refer to the relevant discussions in the above embodiments, which will not be repeated here.
[0072] In some embodiments, the joint includes: a shoulder joint, a forearm joint, a wrist joint, a knee joint, an ankle joint, a hip joint, or a trunk joint.
[0073] In summary, this reducer and the robot using this reducer achieve dynamic balance by setting a counterweight 12, which generates an eccentric force during the revolution of the counterweight 12 to counteract the eccentric force generated during the revolution of the first external gear 21 and the second external gear 22.
[0074] In this document, when it is said that the first component is located on the second component, this can mean that the first component can be directly formed on the second component, or that the third component can be inserted between the first component and the second component.
[0075] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0076] In the above discussion, unless otherwise stated, when used to describe numerical values, the terms “about,” “approximately,” “basically,” etc., indicate a change of + / - 10% in that value.
[0077] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.
Claims
1. A speed reducer, characterized in that, include: An eccentric shaft (1) includes an input section (10) and an eccentric section (11). An external gear set (2) is fitted on the eccentric part (11) and includes: a first external gear (21) and a second external gear (22). The fixed internal gear ring (3) is sleeved on the periphery of the external gear set (2) and meshes with the first external gear (21); The output internal gear (4) is rotatably set inside the fixed internal gear ring (3) and meshes with the second external gear (22); The input part (10), the fixed internal gear ring (3) and the output internal gear (4) are coaxially arranged, and at least one counterweight (12) is sleeved on the eccentric part (11).
2. The reducer as described in claim 1, characterized in that, The eccentricity a between the eccentric part (11) and the input part (10) is in the range of 0 mm. <a≤2mm。 3. The reducer as described in claim 1, characterized in that, The input section (10) is hollow.
4. The reducer as described in claim 1, characterized in that, The first external gear (21) and the second external gear (22) are coaxially arranged and axially connected by a locating pin to rotate synchronously.
5. The reducer as described in claim 1, characterized in that, The eccentric part (11) has an irregular notch (111). The counterweight block (12) is provided with an irregular protrusion (121) that matches the irregular notch (111).
6. The reducer as described in claim 1, characterized in that, A needle roller bearing (23) is fitted on the eccentric part (11); The first external gear (21) and the second external gear (22) are both mounted on the needle roller bearing (23).
7. The reducer as described in claim 1, characterized in that, The lower surface of the output internal gear (4) is connected to an output flange (41). The output internal gear (4) is coaxially arranged with the output flange (41) and is axially connected by a locating pin to rotate synchronously.
8. The reducer as described in claim 1, characterized in that, There are two counterweights (12), located above and below the external gear set (2).
9. The reducer as described in claim 7, characterized in that, The output internal gear (4) is provided with a first thin-walled bearing (42) on its exterior. The output internal gear (4) is rotatably connected to the fixed internal gear ring (3) through the first thin-walled bearing (42); The output flange (41) is provided with a cross roller bearing (43) on its exterior. The output flange (41) is rotatably connected to the fixed internal gear ring (3) via a crossed roller bearing (43); One end of the eccentric shaft (1) extends into the output flange (41); The end of the eccentric shaft (1) is fitted with a second thin-walled bearing (13). The second thin-walled bearing (13) is rotatably connected to the output flange (41); The inner wall of the fixed internal gear ring (3) is provided with a first internal gear part (31) and a mounting part (32). The first external gear (21) meshes with the first internal gear (31); Both the first thin-walled bearing (42) and the crossed roller bearing (43) are connected to the mounting part (32).
10. A robot, characterized in that, include: The joint portion is equipped with a speed reducer as described in any one of claims 1-9; wherein The joints include: shoulder joints, forearm joints, wrist joints, knee joints, ankle joints, hip joints, or trunk joints.