Lightweight planetary spur gear reducer

Abstract

The utility model relates to a kind of lightweight planetary gear reducer, including sun gear, planetary gear, inner ring gear and planet carrier, three are lightweight line gear, sun gear is located in the center of inner ring gear, sun gear and planet carrier are coaxial rotation installation in inner ring gear, planetary gear is different shaft rotation installation in planet carrier and can rotate around its own axis, planetary gear and two are point contact engagement, the tooth surface normal of any contact point of planetary gear is simultaneously with the tooth surface normal of sun gear, inner ring gear corresponding contact point collinear, contact line is cylindrical helix, transmission ratio and helix radius decoupling. Through space curve engagement theory, single stage can realize more than 30 reduction ratio, planetary reducer series is reduced, significantly shorten force flow transmission path, reduce the overall weight, improve carrying capacity and reliability at the same time, systematically solve the technical problems, such as the complex of multi-stage series structure, weight increase, transmission and positioning precision reduction and limited load dispersion capacity, when realizing large reduction ratio in prior art.

Description

Technical Field

[0001] This utility model relates to the field of precision transmission technology for planetary gear systems, specifically a lightweight planetary linear gear reducer. Background Technology

[0002] Planetary gear reducers, as core components in the field of mechanical transmission, are widely used in automobiles, industrial equipment, and robotics due to their advantages of stable transmission, high efficiency, high reliability, and compact structure. As a precision transmission mechanism based on a planetary gear train structure, a planetary gear reducer transmits power through the coordinated meshing of the sun gear, planet gears, and internal gear ring. When the input shaft drives the sun gear to rotate, the planet gears transmit power in a combined motion of revolving around the sun gear and rotating on their own axes, ultimately outputting amplified torque through the planet carrier. The circumferentially even distribution of multiple planet gears achieves load distribution, and the simultaneous meshing of multiple teeth gives it advantages of compact structure, high transmission efficiency, and large output torque. The transmission process is highly stable due to symmetrical meshing, effectively reducing vibration and noise, and significantly improving load-bearing reliability and lifespan. Multi-stage series design can further increase the reduction ratio.

[0003] The structure of a planetary gear reducer mainly includes a sun gear, planet gears, an internal ring gear, and a planet carrier. In existing technology, the sun gear, planet gears, and internal ring gear are all involute gears. The six basic transmission modes of a planetary gear reducer are: when the ring gear is fixed, the sun gear is the driving gear and the planet carrier is the driven gear, achieving reduction in the same direction; when the planet carrier is the driving gear and the sun gear is the driven gear, it is acceleration in the same direction. When the sun gear is fixed, the ring gear is the driving gear and the planet carrier is the driven gear, achieving reduction in the same direction; when the planet carrier is the driving gear and the ring gear is the driven gear, it is acceleration in the same direction. When the planet carrier is fixed, the sun gear is the driving gear and the ring gear is the driven gear, forming a reduction in the opposite direction; when the ring gear is the driving gear and the sun gear is the driven gear, it is acceleration in the opposite direction. Due to the relatively large transmission ratio, the transmission mode with a fixed internal ring gear is more common.

[0004] In the existing technology, the design of planetary reduction mechanisms still has some problems and limitations. Specifically, traditional involute planetary gear reducers are limited by the gear meshing principle and manufacturing process, and the single-stage reduction ratio is usually no more than 10. To achieve a large reduction ratio, a multi-stage series structure is required, which leads to an extension of the dimensional chain and force flow transmission path. The cumulative error of multi-stage transmission reduces positioning accuracy, and the weight increases.

[0005] Due to adjacency constraints (adjacent planetary gears cannot interfere with each other), involute planetary gear reducers can only accommodate a maximum of 3 planetary gears when the reduction ratio is between 5 and 11 (e.g., ...). Figure 1 Its load distribution capability is limited. Utility Model Content

[0006] The purpose of this invention is to provide a lightweight planetary gear reducer that solves the technical problems faced by existing technologies in achieving large reduction ratios, such as complex multi-stage series structures, increased weight, reduced transmission and positioning accuracy, and limited load distribution capabilities.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A lightweight planetary gear reducer includes a sun gear, planet gears, an internal gear ring, and a planet carrier;

[0009] The sun gear is located at the center of the internal gear ring. The sun gear and the planet carrier are coaxially mounted on the internal gear ring. The planet gears are mounted on the planet carrier off-axis and can rotate around their own axes. The planet gears are in point contact with the sun gear and the internal gear ring respectively.

[0010] When the sun gear rotates in the first direction, the trajectories formed by the contact points P1 between the sun gear and the planet gear teeth on the gear body are the first contact lines of the sun gear and the planet gear, respectively, and the trajectories formed in the stationary coordinate system o-xyz are the meshing lines l1; the trajectories formed by the contact points P3 between the planet gear and the internal gear ring on the gear body are the second contact lines of the planet gear and the internal gear ring, respectively, and the trajectories formed in the stationary coordinate system o-xyz are the meshing lines l3; when the sun gear rotates in the second direction opposite to the first direction, the trajectories formed by the contact points P2 between the sun gear and the planet gear teeth on the gear body are the second contact lines of the sun gear and the planet gear teeth, respectively. The second contact line of the planet gear forms the meshing line l2 in the stationary coordinate system o-xyz; the trajectories formed by the contact points P4 between the planet gear and the internal gear ring on the gear body are the first contact lines of the planet gear and the internal gear ring, respectively, and the trajectories formed in the stationary coordinate system o-xyz are the meshing lines l4; the first contact lines of the sun gear, the planet gear, the internal gear ring, the second contact lines of the sun gear, the planet gear, and the internal gear ring are all cylindrical helices, and all meshing lines are straight line segments; the tooth surface normal of any contact point of the planet gear is simultaneously collinear with the tooth surface normals of the corresponding contact points of the sun gear and the internal gear ring.

[0011] Furthermore, in the coordinate system o1-x1y1z1 fixed to the sun gear, the expression for the first contact line of the sun gear is:

[0012] In the coordinate system o2-x2y2z2 fixed to the planetary gear, the expression for the first contact line of the planetary gear is:

[0013] In the coordinate system o3-x3y3z3 fixed to the internal gear ring, the expression for the first contact line of the internal gear ring is:

[0014] In the formula, t1, t2, and t3 are parameters; m1, m2, and m3 are the helix radii of the corresponding cylindrical helices of the sun gear, planet gear, and internal gear ring, respectively; and n1, n2, and n3 are the helix radii of the corresponding cylindrical helices of the sun gear, planet gear, and internal gear ring, respectively. Double the conductance.

[0015] Furthermore, the transformation relationship from coordinate system o1-x1y1z1 to coordinate system o2-x2y2z2 is as follows:

[0016] In the formula, a is the center distance.

[0017]

[0018] The transmission ratio i between the sun gear and planet gears 12 It is the inverse ratio of the lead of the contact lines of the two, and the transmission ratio i 12 It is independent of the spiral radii m1 and m2 of the sun gear and planet gear;

[0019] The transformation relationship from coordinate system o2-x2y2z2 to coordinate system o3-x3y3z3 is as follows: In the formula, a is the center distance.

[0020]

[0021] The transmission ratio i between the planetary gears and the internal gear ring 23 It is the inverse ratio of the lead of the contact lines of the two, and the transmission ratio i 23 It is unrelated to the helical radii m2 and m3 of the planetary gears and internal gear ring.

[0022] Furthermore, in the coordinate system o2-x2y2z2, the expression for the tangent vector of the first contact line of the sun gear at the contact point on the tooth surface is:

[0023] The expression for the tangent vector of the first contact line of the planetary gear is:

[0024] The expression for the tangent of the first contact line of the internal gear ring is:

[0025] Furthermore, on the same tooth of the sun gear, the second contact line of the sun gear is formed by rotating the first contact line of the sun gear around its own axis by an angle. It is obtained that, between adjacent teeth of the sun gear, the second contact line of the sun gear is obtained by rotating the first contact line of the sun gear around its own axis by an angle. get, Where N1 is the number of teeth on the sun gear;

[0026] On the same tooth of the planetary gear, the second contact line of the planetary gear is rotated by an angle from the first contact line of the planetary gear around the axis of the planetary gear itself. It is obtained that, between adjacent teeth of the planetary gears, the second contact line of the planetary gears is obtained by rotating the first contact line of the planetary gears around the axis of the planetary gears by an angle. get, Where N2 is the number of teeth on the planetary gear;

[0027] On the same tooth of the internal gear ring, the second contact line of the internal gear ring is rotated by an angle around the axis of the internal gear ring from the first contact line of the internal gear ring. It is obtained that, between adjacent teeth of the internal gear ring, the second contact line of the internal gear ring is obtained by rotating the first contact line of the internal gear ring around its own axis by an angle. get, Where N3 is the number of teeth on the internal gear ring;

[0028] When m1·i 12 ·i 23 >m2·i 23 When the thickness is greater than m3, the tooth thickness and tooth space width of the sun gear, planet gears, and internal gear ring satisfy the following relationship:

[0029] When m1·i 12 ·i 23 >m3>m2·i 23 At that time, the tooth thickness and tooth space width of the sun gear, planet gears, and internal gear ring satisfy the following relationship:

[0030] Furthermore, the reducer improves the reduction ratio through a multi-stage series design; the reduction ratio calculation formula for a single-stage lightweight planetary gear reducer is as follows: When configured as a two-stage transmission with each stage having a transmission ratio of 30, the combined transmission ratio of the two reduction ratios is 900.

[0031] Furthermore, the sun gear and planet gears are configured with fewer teeth and greater tooth thickness.

[0032] Furthermore, when the reduction ratio of the reducer is in the range of 5 to 11, the number of planetary gears can be arranged as 4.

[0033] Furthermore, the sun gear, planet gears, and internal gear ring are all lightweight profile gears, with their gear bodies constructed using the corresponding contact line as the generatrix, and the gear tooth profiles being circular arcs, elliptical arcs, involutes, or cycloids.

[0034] Furthermore, the tooth profiles of the sun gear, planet gears, and internal gear ring are all convex arcs; or the sun gear tooth profile is a convex arc, the planet gear tooth profile is a concave arc or a straight line, and the internal gear ring tooth profile is a convex arc; or the sun gear tooth profile is a concave arc or a straight line, the planet gear tooth profile is a convex arc, and the internal gear ring tooth profile is a concave arc or a straight line.

[0035] In summary, this utility model has the following advantages:

[0036] (1) Compared with the traditional involute planetary gear reducer which requires multiple stages of transmission to achieve a large reduction ratio, the present invention is equipped with a lightweight planetary gear reducer with 3 planetary gears, which can achieve a reduction ratio of more than 30 in a single stage. The number of planetary reducer stages is reduced by 50%, which significantly shortens the force transmission path, simplifies the structure, and reduces the overall structural weight.

[0037] (2) The planetary gear diameter of the lightweight spur gear pair can be designed to be smaller. Under the constraint of adjacency conditions, the traditional involute planetary spur gear reducer can only arrange a maximum of 3 planetary gears in the range of reduction ratio 5 to 11. The lightweight planetary spur gear reducer of this utility model can realize the arrangement of 4 planetary gears, which improves the load-bearing performance.

[0038] (3) The parameter configuration of fewer teeth and larger tooth thickness can significantly improve the bending strength of the gear teeth and improve the reliability of the lightweight planetary gear reducer. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of an involute planetary gear reducer with a transmission ratio of 11 in the prior art.

[0040] Figure 2 This is a schematic diagram of the first contact line of the sun gear, the first contact line of the planet gear, the second contact line of the sun gear, and the second contact line of the planet gear in this utility model;

[0041] Figure 3 This is a schematic diagram of the first contact line of the planetary gear, the first contact line of the internal gear ring, the second contact line of the planetary gear, and the second contact line of the internal gear ring in this utility model.

[0042] Figure 4 This is a schematic diagram of the structure of a lightweight planetary linear gear reducer with a transmission ratio of 11 according to Embodiment 1 of this utility model.

[0043] Figure 5 This is a schematic diagram of the structure of a lightweight planetary linear gear reducer with a transmission ratio of 11 according to Embodiment 1 of this utility model. The planet carrier 4 is hidden.

[0044] Figure 6 This is a schematic diagram of the sun gear in Embodiment 1 of this utility model;

[0045] Figure 7 This is a schematic diagram of the planetary gear structure in Embodiment 1 of this utility model;

[0046] Figure 8 This is a schematic diagram of the internal gear ring of Embodiment 1 of this utility model;

[0047] Figure 9 This is a schematic diagram of a lightweight planetary linear gear reducer with a transmission ratio of 30 according to Embodiment 2 of this utility model. The planet carrier 4 is hidden.

[0048] In the picture:

[0049] 1-Sun gear; 11-First contact line of the sun gear; 12-Second contact line of the sun gear;

[0050] 2-Planetary gear; 21-First contact line of planetary gear; 22-Second contact line of planetary gear;

[0051] 3-Internal gear ring; 31-First contact line of internal gear ring; 32-Second contact line of internal gear ring;

[0052] 4-Planet Carrier. Detailed Implementation

[0053] The present invention will now be described in further detail.

[0054] This utility model proposes a lightweight planetary gear reducer, which systematically solves the technical contradictions of existing planetary reducers based on involute gears in achieving the three major goals of lightweighting, high reduction ratio, and high load-bearing capacity through the spatial curve meshing theory. It also solves the technical problems faced by existing technologies in achieving large reduction ratios, such as complex multi-stage series structures, increased weight, reduced transmission and positioning accuracy, and limited load distribution capabilities.

[0055] By adopting the lightweight linear gear design theory, this utility model proposes a lightweight planetary linear gear reducer that can achieve a reduction ratio of over 30 in a single stage. Compared with the prior art, the number of planetary reducer stages is reduced by 50%, which significantly shortens the force transmission path, avoids the problem of dimensional chain extension caused by multi-stage structures, reduces the overall weight, achieves the goal of lightweighting, and at the same time improves the load-bearing capacity and reliability.

[0056] A lightweight planetary gear reducer includes a sun gear 1, planet gears 2, an internal ring gear 3, and a planet carrier 4. The assembly relationship is as follows: the sun gear 1 is coaxially mounted on the internal ring gear 3; the planet carrier 4 is coaxially mounted on the internal ring gear 3; and the planet gears 2 are mounted on the planet carrier 4 off-axis. Each planet gear 2 can rotate around its own axis. The planet gears 2 mesh with both the sun gear 1 and the internal ring gear 3. The number of planet gears 2 can be single or multiple, and their arrangement must satisfy the adjacency condition, meaning that adjacent planet gears 2 do not interfere with each other.

[0057] Sun gear 1, planet gear 2, and internal ring gear 3 are all lightweight linear gears. The meshing between planet gear 2 and sun gear 1 and internal ring gear 3 is point contact meshing. When sun gear 1 rotates in one direction, the trajectory formed on the gear body by the tooth surface contact point P1 of sun gear 1 and planet gear 2 is the first contact line 11 of sun gear and the first contact line 21 of planet gear. The trajectory formed in the stationary coordinate system o-xyz is the meshing line l1. The trajectory formed on the gear body by the tooth surface contact point P3 of planet gear 2 and internal ring gear 3 is the second contact line 22 of planet gear and the second contact line 32 of internal ring gear. The trajectory formed in the stationary coordinate system o-xyz is the meshing line l3. When the sun gear 1 rotates in the opposite direction, the trajectory formed by the tooth surface contact point P2 of the sun gear 1 and the planet gear 2 on the gear body is the second contact line 12 of the sun gear and the second contact line 22 of the planet gear. The trajectory formed in the stationary coordinate system o-xyz is the meshing line l2. The trajectory formed by the tooth surface contact point P4 of the planet gear 2 and the internal gear ring 3 on the gear body is the first contact line 21 of the planet gear and the first contact line 31 of the internal gear ring. The trajectory formed in the stationary coordinate system o-xyz is the meshing line l4. The axis z1 of the sun gear 1, the axis z2 of the planet gear 2, and the axis z3 of the internal gear ring 3 are all on the plane xoz. The meshing lines l1 and l2, and l3 and l4 are symmetrical about the plane xoz. The angles between the plane formed by the meshing line l1 and the axis z1 of the sun gear 1 and the plane xoz, and the angles between the plane formed by the meshing line l2 and the axis z1 of the sun gear 1 and the plane xoz, are all δ1. The angles between the plane formed by the meshing line l1 and the axis z2 of the planet gear 2 and the plane xoz, and the angles between the plane formed by the meshing line l2 and the axis z2 of the planet gear 2 and the plane xoz, are all δ2. The angles between the plane formed by the meshing line l3 and the axis z2 of the planet gear 2 and the plane xoz, and the angles between the plane formed by the meshing line l4 and the axis z2 of the planet gear 2 and the plane xoz, are all δ2′. The angles between the plane formed by the meshing line l3 and the axis z3 of the internal gear ring 3 and the plane xoz, and the angles between the plane formed by the meshing line l4 and the axis z3 of the internal gear ring 3 and the plane xoz, are all δ3.

[0058] The first contact line 11 of the sun gear, the first contact line 21 of the planet gear, the first contact line 31 of the internal gear ring, the second contact line 12 of the sun gear, the second contact line 22 of the planet gear, and the second contact line 32 of the internal gear ring are all cylindrical helices, and the meshing lines are all straight segments. During meshing, the contact stress distribution on the tooth surface is more uniform, reducing local stress concentration.

[0059] In the coordinate system o1-x1y1z1 fixed to the sun gear 1, the expression for the first contact line 11 of the sun gear is:

[0060] In the coordinate system o2-x2y2z2 fixed to planetary gear 2, the expression for the first contact line 21 of the planetary gear is:

[0061] In the coordinate system o3-x3y3z3 fixed to the internal gear ring 3, the expression for the first contact line 31 of the internal gear ring is:

[0062] In the formula, t1, t2, and t3 are parameters; m1, m2, and m3 are the helix radii of the cylindrical helices corresponding to sun gear 1, planet gear 2, and internal gear ring 3, respectively; and n1, n2, and n3 are the values ​​of the cylindrical helices corresponding to sun gear 1, planet gear 2, and internal gear ring 3. Double the conductance.

[0063] The transformation relationship from coordinate system o1-x1y1z1 to coordinate system o2-x2y2z2 is as follows: In the formula, a is the center distance. The transmission ratio i between sun gear 1 and planet gear 2 12 It is the inverse ratio of their contact line lead, i. 12 =n2 / n1, the transmission ratio i between sun gear 1 and planet gear 2 12 This is independent of the spiral radii m1 and m2 of the sun gear 1 and planet gear 2. When m2 < m1·i 12 At the same time, compared with involute gears, the planetary gear 2, which uses lightweight linear gears, achieves a reduction in diameter and volume.

[0064] Similarly, the transformation relationship from coordinate system o2-x2y2z2 to coordinate system o3-x3y3z3 is as follows: In the formula, a is the center distance. The transmission ratio i between planetary gear 2 and internal gear ring 3 23 It is the inverse ratio of their contact line lead, i. 23 =n3 / n2, the transmission ratio i between planetary gear 2 and internal gear ring 3 23 This is independent of the helical radii m2 and m3 of planetary gear 2 and internal gear ring 3. When m3 < m2·i 23 At that time, compared with involute gears, the internal gear ring 3 using lightweight linear gears achieves a reduction in diameter and volume relative to planetary gears 2; when m3 < m1·i 12 ·i 23 At the same time, compared with involute gears, the internal gear ring 3 using lightweight linear gears achieves a reduction in diameter and volume relative to the sun gear 1.

[0065] A lightweight planetary linear gear reducer is disclosed, comprising a sun gear 1, planet gears 2, and an internal gear ring 3, all of which are lightweight linear gears. The gear bodies are constructed using the contact line as the generatrix. The tooth profiles of these gear bodies can be of any shape (e.g., circular arc, elliptical arc, involute, cycloid, etc.) to adapt to wear requirements under different working conditions. Furthermore, the normal to the tooth surface of any contact point of planet gear 2 is simultaneously collinear with the normals to the tooth surfaces of the corresponding contact points of sun gear 1 and internal gear ring 3. Specifically, according to linear gear meshing theory, for a pair of tooth surfaces to not disengage and not interfere at the contact point, their normals must be collinear. In the coordinate system o2-x2y2z2, the normal to the tooth surface of any contact point of planet gear 2 must simultaneously be collinear with the normals to the tooth surfaces of the corresponding contact points of sun gear 1 and internal gear ring 3. and Coplanar, that is and Mixed product The common normal to the tooth surfaces of sun gear 1, planet gear 2, and internal gear ring 3 is: In the coordinate system o2-x2y2z2, the expression for the tangent vector of the first contact line 11 of the sun gear at the tooth surface contact point is: The expression for the tangent vector of the first contact line 21 of the planetary gear is: The expression for the tangent of the first contact line 31 of the internal gear ring is: There are 5 constraint equations for parameters m1, n1, m2, n2, m3, n3, δ1, δ2, δ2′, δ3 and tangent a. Therefore, 6 of these parameters can be given according to design requirements, and the other 5 parameters can be calculated from the constraint equations. This satisfies the linear gear meshing theory, ensuring that the tooth surfaces of the sun gear 1, planet gear 2, and internal gear ring 3 do not separate or interfere at the contact point, avoiding tooth surface scraping or separation during meshing, significantly reducing the tooth wear rate, and extending the overall service life and operational reliability of the reducer.

[0066] The tooth profiles of the sun gear 1, planet gear 2 and internal gear ring 3 can all be convex arcs, or they can be convex arcs, concave arcs (or straight lines) and convex arcs respectively, or they can be concave arcs (or straight lines), convex arcs and concave arcs (or straight lines) respectively, etc.

[0067] A lightweight planetary gear reducer, with zero backlash in nominal size and standard mounting condition, introduces backlash through a tolerance system to avoid transmission backlash errors caused by traditional assembly backlash, further improving positioning accuracy and transmission smoothness. On the same tooth of the sun gear, the second contact line 12 of the sun gear is rotated by an angle around the axis of the sun gear 1 from the first contact line 11 of the sun gear. It is obtained that, between adjacent teeth of the sun gear, i.e. on the same tooth groove, the second contact line 12 of the sun gear rotates by an angle around the axis of the sun gear 1 from the first contact line 11 of the sun gear. get, N1 represents the number of teeth on the sun gear 1; similarly, the same logic applies to the planet gear 2 with N2 teeth and the internal gear ring 3 with N3 teeth. as well as The geometric meaning of m1·i. 12 ·i 23 >m2·i 23 When the thickness is greater than m3, the tooth thickness and tooth space width of the sun gear 1, planet gear 2, and internal gear ring 3 satisfy the following relationship: When m1·i 12 ·i 23 >m3>m2·i 23 At that time, the tooth thickness and tooth space width of the sun gear 1, planet gear 2, and internal gear ring 3 satisfy the following relationship:

[0068] A lightweight planetary spool gear reducer can further increase its reduction ratio through a multi-stage cascade design, achieving an ultra-high reduction ratio while maintaining a compact design. The reduction ratio calculation formula for a single-stage lightweight planetary spool gear reducer is as follows: When configured as a two-stage transmission with each stage having a transmission ratio of 30, the combined transmission ratio of the two stages is 900, which meets the requirements of ultra-high reduction ratio scenarios.

[0069] Example 1:

[0070] Example 1 shows a lightweight planetary linear gear reducer with a transmission ratio of 11.

[0071] First, given:

[0072] The expression for the first contact line 11 of the sun gear is: The number of teeth on the sun gear 1 is N1 = 4;

[0073] The expression for the first contact line 21 of the planetary gear is: Planetary gear 2 has 18 teeth (N2 = 18).

[0074] The expression for the first contact line 31 of the internal gear ring is: The number of teeth on the internal gear ring 3 is N3 = 40.

[0075] Other parameters were calculated as follows: center distance a = 21.74, δ1 = 18.80°, δ2 = δ2′ = 10.32°, δ3 = 4.11°.

[0076] The tooth profiles of the sun gear 1, planet gear 2, and internal gear ring 3 are convex arc, concave arc, and convex arc, respectively.

[0077] Example 2:

[0078] Example 2 shows a lightweight planetary linear gear reducer with a transmission ratio of 30.

[0079] First, given:

[0080] The expression for the first contact line 11 of the sun gear is: The number of teeth on the sun gear 1 is N1 = 2;

[0081] The expression for the first contact line 21 of the planetary gear is: Planetary gear 2 has 23 teeth (N2 = 23).

[0082] The expression for the first contact line 31 of the internal gear ring is: The number of teeth on the internal gear ring is N3 = 58.

[0083] Other parameters were calculated as follows: center distance a = 8.234, δ1 = 30.98°, δ2 = 8.97°, δ2′ = 24.51°, δ3 = 10.89°.

[0084] The tooth profiles of the sun gear 1, planet gear 2, and internal gear ring 3 are all convex arcs.

[0085] In summary, the lightweight planetary linear gear reducer of this application addresses the core pain points of traditional involute planetary reducers through spatial curve meshing theory and lightweight linear gear design, achieving significant breakthroughs in key performance dimensions such as lightweighting, reduction ratio, load-bearing capacity, precision, and reliability.

[0086] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A lightweight planetary spur gear reducer characterized by: It includes a sun gear (1), planet gears (2), an internal gear ring (3), and a planet carrier (4); The sun gear (1) is located at the center of the internal gear ring (3). The sun gear (1) and the planet carrier (4) are coaxially mounted on the internal gear ring (3). The planet gear (2) is mounted on the planet carrier (4) on a different axis and can rotate around its own axis. The planet gear (2) makes point contact with the sun gear (1) and the internal gear ring (3) respectively. When the sun gear (1) rotates in the first direction, the trajectories formed by the contact points P1 of the sun gear (1) and the planet gear (2) on the gear body are the first contact line (11) of the sun gear and the first contact line (21) of the planet gear, respectively, and the trajectories formed in the stationary coordinate system o-xyz are the meshing lines l1; the trajectories formed by the contact points P3 of the planet gear (2) and the internal gear ring (3) on the gear body are the second contact line (22) of the planet gear and the second contact line (32) of the internal gear ring, respectively, and the trajectories formed in the stationary coordinate system o-xyz are the meshing lines l3; when the sun gear (1) rotates in the second direction opposite to the first direction, the trajectories formed by the contact points P2 of the sun gear (1) and the planet gear (2) on the gear body are the second contact line (12) of the sun gear and the second contact line (32) of the planet gear, respectively. The contact line (22) forms a meshing line l2 in the stationary coordinate system o-xyz; the contact points P4 between the planetary gear (2) and the internal gear ring (3) form the first contact line (21) of the planetary gear and the first contact line (31) of the internal gear ring on the gear body, respectively, and the meshing line l4 forms a meshing line l4 in the stationary coordinate system o-xyz; the first contact line (11) of the sun gear, the first contact line (21) of the planetary gear, the first contact line (31) of the internal gear ring, the second contact line (12) of the sun gear, the second contact line (22) of the planetary gear, and the second contact line (32) of the internal gear ring are all cylindrical helices, and all meshing lines are straight line segments; the tooth surface normal of any contact point of the planetary gear (2) is collinear with the tooth surface normal of the corresponding contact point of the sun gear (1) and the internal gear ring (3).

2. The lightweight planetary gear reducer according to claim 1, characterized in that: In the coordinate system o1-x1y1z1 fixed with the sun gear (1), the expression of the first contact line (11) of the sun gear is In the coordinate system o2-x2y2z2 fixed with the planetary gear (2), the expression of the first contact line (21) of the planetary gear is In the coordinate system o3-x3y3z3 fixed with the inner gear ring (3), the expression of the first contact line (31) of the inner gear ring is In the formula, t1, t2, t3 are variable parameters, m1, m2, m3 are helical radii of the corresponding cylindrical helix of the sun gear (1), the planet gear (2) and the inner ring gear (3) respectively, n1, n2, n3 are the number of the corresponding cylindrical helix of the sun gear (1), the planet gear (2) and the inner ring gear (3) respectively times of the lead.

3. The lightweight planetary spur gear reducer of claim 2, wherein: The transformation relationship from coordinate system o1-x1y1z1 to coordinate system o2-x2y2z2 is as follows: where a is the center distance, The transmission ratio i of the sun gear (1) to the planet gears (2) 12 is inversely proportional to the contact line lead of both, and this transmission ratio i 12 is independent of the helix radii m1, m2 of the sun gear (1), the planet gears (2) The following conversion relationship exists from the coordinate system o2-x2y2z2 to the coordinate system o3-x3y3z3: In the formula, a is the distance from the center. The transmission ratio i of the planetary gear (2) to the inner ring gear (3) 23 is inversely proportional to the contact line lead of both, and the transmission ratio i 23 is independent of the helix radii m2, m3 of the planetary gear (2), the inner ring gear (3).

4. The lightweight planetary gear reducer according to claim 3, characterized in that: In the coordinate system o2-x2y2z2, the expression of the tangent vector of the first contact line (11) of the sun gear at the point of tooth surface contact is The expression of the tangent vector of the first contact line (21) of the planetary wheel is The expression of the tangent to the first contact line (31) of the inner ring is 5. The lightweight planetary gear reducer according to claim 3, characterized in that: On the same tooth of the sun gear (1), the sun gear second contact line (12) is rotated by the sun gear first contact line (11) around the sun gear (1) own axis angle obtained; between the adjacent teeth of the sun gear (1), the sun gear second contact line (12) is rotated by the sun gear first contact line (11) around the sun gear (1) own axis angle obtained, wherein N1 is the number of teeth of the sun gear (1); On the same tooth of the planet wheel (2), the planet wheel second contact line (22) is rotated by the planet wheel first contact line (21) by an angle obtained; between adjacent teeth of the planet wheel (2), the planet wheel second contact line (22) is rotated by the planet wheel first contact line (21) by an angle obtained, where N2 is the number of teeth of the planet wheel (2); On the same tooth of the inner ring (3), the inner ring second contact line (32) is rotated by the inner ring first contact line (31) by an angle On the same tooth of the inner ring (3), the inner ring second contact line (32) is rotated by the inner ring first contact line (31) by an angle On the same tooth of the inner ring (3), the inner ring second contact line (32) is rotated by the inner ring first contact line (31) by an angle where N3 is the number of teeth of the inner ring (3); when m1 · i 12 ·i 23 > m2 · i 23 > m3, the tooth thickness, tooth groove width of the sun gear (1), the planet gear (2) and the inner gear ring (3) satisfy the following relationship: When m1·i 12 ·i 23 >m3>m2·i 23 At that time, the tooth thickness and tooth space width of the sun gear (1), planet gear (2) and internal gear ring (3) satisfy the following relationship:

6. The lightweight planetary gear reducer according to claim 5, characterized in that: The reducer improves the reduction ratio through a multi-stage series design; the reduction ratio calculation formula for a single-stage lightweight planetary gear reducer is as follows: When configured as a two-stage transmission with each stage having a transmission ratio of 30, the combined transmission ratio of the two-stage reduction ratios is 900.

7. The lightweight planetary gear reducer according to claim 1, characterized in that: The sun gear (1) and planet gear (2) are configured with fewer teeth and larger tooth thickness.

8. The lightweight planetary gear reducer according to claim 1, characterized in that: When the reduction ratio of the reducer is in the range of 5 to 11, the number of planetary gears (2) can be arranged as 4.

9. The lightweight planetary gear reducer according to claim 1, characterized in that: The sun gear (1), planet gear (2) and internal gear ring (3) are all lightweight linear gears. Their gear bodies are constructed with the corresponding contact line as the generatrix, and the gear tooth profile is a circular arc, elliptical arc, involute or cycloid.

10. The lightweight planetary gear reducer according to claim 1, characterized in that: The tooth profiles of the sun gear (1), planet gear (2) and internal gear ring (3) are all convex arcs; or the tooth profile of the sun gear (1) is a convex arc, the tooth profile of the planet gear (2) is a concave arc or a straight line, and the tooth profile of the internal gear ring (3) is a convex arc; or the tooth profile of the sun gear (1) is a concave arc or a straight line, the tooth profile of the planet gear (2) is a convex arc, and the tooth profile of the internal gear ring (3) is a concave arc or a straight line.

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