Differential mechanism and speed reducer

Abstract

The application discloses a differential mechanism and a speed reducer, and belongs to the technical field of transmission devices, which comprises a first sun gear, a first planetary gear set, a second sun gear, a second planetary gear set and a planetary differential frame, the first planetary gear set comprises a plurality of first planetary gears which are respectively engaged with the first sun gear, the second planetary gear set comprises a plurality of second planetary gears which are respectively engaged with the second sun gear, the first planetary gears and the second planetary gears are rigidly coaxially connected one by one and are rotationally arranged in the planetary differential frame, by adopting the plurality of first planetary gears and the plurality of second planetary gears which are rigidly coaxially connected, the number of parts is greatly reduced, the requirement of compact design of a forming press is met, the assembly process complexity is reduced, the transmission stability is prevented from being influenced by excessive superposition of transmission gaps, and the left and right engagement pairs are guaranteed to have the same center distance by constraint of an equal center distance tooth matching constraint formula, so that the problem of assembly interference of the planetary gears is solved, and the overall transmission coaxiality is higher.

Description

Technical Field

[0001] This invention relates to the field of transmission technology, and in particular to a differential mechanism and a reducer. Background Technology

[0002] The preparation process of high-performance ferrite magnetic tiles used in the electronics industry is as follows: Ferrite slurry (containing water, binder, lubricant and other components) is injected into the mold cavity, the magnetic powder is oriented and oriented under a strong magnetic field environment, hydraulic pressure is applied simultaneously to squeeze out the water in the slurry, and the magnetic tile blank with uniform thickness is pressed by a hydraulic press.

[0003] The pressing density of the green magnetic tile blank directly determines the key electromagnetic properties of the finished product, such as magnetic permeability and high-frequency loss. However, existing wet-pressing hydraulic presses for forming magnetic tiles have many drawbacks: the moisture content of the blanks pressed by these machines is as high as 12% to 13%, resulting in extremely low strength. During demolding and transfer, defects such as delamination, cracking, deformation, and corner chipping are easily observed, leading to a high product defect rate. The finished product qualification rate is highly dependent on the performance of the forming hydraulic press. Furthermore, the equipment suffers from slow production cycle time and high energy costs. Based on this industry situation, the market has placed stringent demands on the operating speed, pressure stability, and smoothness of transmission switching of forming presses under dual operating conditions.

[0004] When the forming press is working, there are three working conditions: idle stroke, pressing stroke, and demolding stroke. The speed and torque requirements of the transmission system are completely different for these three working conditions, and this difference directly affects the forming yield of ferrite magnetic tile blanks and the production cycle of the whole machine.

[0005] During the idle stroke, there is no pressure load. The transmission mechanism needs to drive the mold to descend quickly, close the mold, and return at high speed to quickly complete the filling, mold clearing, and reset actions, which greatly shortens the standby time of a single molding and improves the batch molding cycle of magnetic tiles. The pressing stroke is a critical stage of compaction, requiring stable and continuous low-speed output of high torque. This stable high torque output ensures that the density difference between the top and bottom, edges and center of the entire magnetic tile blank is controlled within a minimal range, preventing localized material shortages and excessive density gradients due to pressure fluctuations. This guarantees the consistency of magnetic permeability and high-frequency loss after sintering. To match the dual process requirements of "high-speed efficiency and low-speed stable pressure for density preservation" in magnetic tile forming, the industry urgently needs differential transmission devices with two independent input terminals that can switch between high-speed and high-torque outputs in a time-sharing manner.

[0006] Demolding wet-pressed magnetic tiles is essentially a delicate battle against "extremely low strength, high viscosity, strong magnetic attraction, and complex stress." Before the ejection action begins, the system needs a slow pressure release process (usually 0.5-2 seconds) to allow some of the residual stress inside the blank to dissipate naturally, preventing sudden stress release during ejection from causing cracking. The ejection action needs to be extremely stable in speed, with the demolding stroke accurate to the micrometer level.

[0007] Referring to Chinese invention patent CN119163735A, in traditional differential structures, the two sets of sun gears cannot directly engage for transmission. Two independent planetary gear sets must be installed in between to complete meshing and achieve differential speed adjustment. The parallel arrangement of the two planetary gear assemblies significantly increases the axial and radial dimensions of the transmission components, resulting in a large overall size. However, the internal transmission housing of the forming press has limited installation space, and a large-volume differential reduction mechanism encroaches on the internal layout, hindering a compact design. Furthermore, the double planetary gear set has numerous components, complex assembly processes, and overlapping transmission clearances reduce transmission stability during switching between operating conditions, making it difficult to simultaneously meet the dual requirements of high-speed idle travel and low-speed heavy-duty pressing in the forming press. Summary of the Invention

[0008] In order to overcome the defects of the existing technology, the present invention provides a differential mechanism and a reducer.

[0009] The technical solution adopted by this invention to solve its technical problem is: a differential mechanism, comprising: The left meshing pair includes a first sun gear and a first planetary gear set, wherein the first planetary gear set includes multiple sets of first planetary gears that mesh with the first sun gear respectively. The right-side meshing pair includes a second sun gear and a second planetary gear set, wherein the second planetary gear set includes multiple sets of second planetary gears that mesh with the second sun gear respectively. The planetary differential carrier has the first planetary gear and the second planetary gear rigidly coaxially connected one-to-one and rotatably mounted in the planetary differential carrier; The center distance between the first sun gear and the first planet gear, and the center distance between the second sun gear and the second planet gear, are L. The relationship between the external meshing center distances of the gears is as follows: The formula for tooth matching constraint is: in: This is the number of teeth on the first sun gear. This represents the number of teeth on the first planetary gear. The module of the left meshing pair gear. The helix angle of the pitch circle of the left meshing pair gear; This is the number of teeth on the second planetary gear. This is the number of teeth on the second sun gear. The module of the right-side meshing pair gear. The helix angle of the pitch circle of the right-side meshing pair gear; , , , All are positive integers and satisfy: .

[0010] When applied to the operation of a molding press, the differential mechanism is set with two standard operating conditions: First, the second sun gear is locked, and power is input through the first sun gear, causing the planetary differential carrier to rotate and output low-speed, high-torque power, which is adapted to the pressing stroke of the molding press to achieve stable compaction and molding; Second, the first sun gear is locked, and power is input through the second sun gear, causing the planetary differential carrier to rotate and output high-speed power, which is adapted to the quick reset of the molding press during the idle stroke and shortens the standby cycle.

[0011] Preferably, when the second sun gear is locked and the first sun gear is used as input, the ratio of the planetary differential carrier speed to the first sun gear speed is: When the first sun gear is locked and the second sun gear is used as input, the ratio of the planetary differential gear speed to the second sun gear speed is: in: This is the rotational speed of the first sun gear. This refers to the rotational speed of the second sun gear. This refers to the rotational speed of the planetary differential.

[0012] Preferably, when the planetary differential gear is fixed, the first sun gear, the first planet gear, the second planet gear, and the second sun gear form a fixed-axis gear train, which can realize transmission with the same rotation direction but different speeds; Transmission ratio with the first sun gear as input and the second sun gear as output for: A growth rate can be achieved.

[0013] Transmission ratio with the second sun gear as input and the first sun gear as output for: It can achieve deceleration.

[0014] Preferably, the number of the first planetary gear and the second planetary gear is N, where N is also the number of teeth on the first sun gear. Number of teeth of the second sun gear The greatest common divisor of the number of teeth on the first sun gear. Number of teeth of the second sun gear When multiple common divisors exist, N can be chosen in several ways, among which N is preferred. 3.

[0015] Preferably, each pair of first and second planetary gears is integrally formed and rotatably mounted in the planetary differential carrier via a rotating shaft. The planetary differential carrier is an integrally formed cage structure with multiple openings on its four side walls.

[0016] Preferably, the number of openings is the same as the number of first planetary gears and second planetary gears, and the outer sides of the first planetary gears and / or the second planetary gears are partially located in the openings, that is, the outer sides of the first planetary gears and / or the second planetary gears extend outward into the openings.

[0017] Preferably, the first sun gear and the second sun gear are each integrally formed with a transmission shaft, and the outer end of the transmission shaft is provided with a transmission spline. The first sun gear and the second sun gear are respectively connected to different motors through the transmission shaft and the transmission spline.

[0018] A speed reducer includes the aforementioned differential mechanism and a speed reduction mechanism; the speed reduction mechanism has an input drive shaft on its upper part, and an input drive end gear is keyed to the input drive shaft. A bevel gear is coaxially keyed to one side of the planetary differential, and the bevel gear meshes with the input drive end gear plate.

[0019] Preferably, the input transmission end gear disk includes a disk base and arc-shaped end face teeth arranged on the disk base, and the bevel gear is an arc-shaped bevel gear. A receiving space is formed above the disk base, and the lower part of the planetary differential carrier is placed into the receiving space. That is, with the axis of the input transmission end gear disk as the projection direction, the planetary differential carrier as a whole is located within the inner circle of a circle of arc end face teeth.

[0020] Preferably, the reducer also includes an upper housing and a lower housing, with the differential mechanism disposed in the upper housing and the reduction mechanism disposed in the lower housing; The upper housing is provided with a mounting base, and the planetary differential gear is rotatably mounted in the upper housing via the mounting base.

[0021] The beneficial effects of this invention are as follows: Compared with the prior art, by using multiple sets of rigidly coaxially connected first and second planetary gears to replace the traditional independent planetary gear sets, the number of parts is greatly reduced, the overall size of the differential mechanism is compressed, the compact design requirements of the forming press are met, the assembly process complexity is reduced, and the excessive superposition of transmission clearances is avoided from affecting transmission stability. At the same time, it takes into account the dual use requirements of high-speed idle stroke and low-speed heavy-load pressing of the press. Furthermore, by using the equal center distance tooth matching constraint formula, the center distance of the left and right meshing pairs is ensured to be completely consistent, thereby solving the problem of planetary gear assembly interference and achieving higher overall transmission coaxiality. Attached Figure Description

[0022] Figure 1 The three-dimensional differential mechanism in the embodiment of the present invention Figure 1 ; Figure 2 This is a cross-sectional schematic diagram of the differential mechanism in an embodiment of the present invention; Figure 3 The three-dimensional differential mechanism in the embodiment of the present invention Figure 2 (Planetary differential gear omitted); Figure 4 This is a partially exploded schematic diagram of the differential mechanism in an embodiment of the present invention (planetary differential frame omitted). Figure 5 This is a perspective view of the planetary differential frame in an embodiment of the present invention; Figure 6 This is a perspective view of the first planetary gear and the second planetary gear in an embodiment of the present invention; Figure 7 The three-dimensional representation of the reducer in this embodiment of the invention. Figure 1 ; Figure 8 This is a cross-sectional schematic diagram of the reducer in an embodiment of the present invention; Figure 9 The three-dimensional representation of the reducer in this embodiment of the invention. Figure 2 (Upper shell omitted); Figure 10 The three-dimensional representation of the reducer in this embodiment of the invention. Figure 3 (Upper housing and differential mechanism omitted).

[0023] In the diagram, 10 is the left meshing pair; 11 is the first sun gear; 12 is the first planet gear; 20 is the right meshing pair; 21 is the second sun gear; 22 is the second planet gear; 31 is the drive shaft; 32 is the drive spline; 40 is the planetary differential carrier; 41 is the opening; 42 is the bevel gear; 51 is the input drive shaft; 52 is the input drive end gear; 53 is the disc base; 54 is the arc end face tooth; 61 is the upper housing; 62 is the mounting base; and 63 is the lower housing. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] As attached Figure 1-6 As shown, the present invention provides a differential mechanism, comprising: The left meshing pair 10 includes a first sun gear 11 and a first planet gear set, the first planet gear set including multiple sets of first planet gears 12 that mesh with the first sun gear 11 respectively; The right-side meshing pair 20 includes a second sun gear 21 and a second planetary gear set, the second planetary gear set including multiple sets of second planetary gears 22 that mesh with the second sun gear 21 respectively; The planetary differential carrier 40 has a rigid coaxial connection between the first planetary gear 12 and the second planetary gear 22, which are respectively rotatably mounted in the planetary differential carrier 40. The center distance between the first sun gear 11 and the first planet gear 12, and the center distance between the second sun gear 21 and the second planet gear 22, are L. The relationship between the external meshing center distances of the gears is: The formula for tooth matching constraint is: in: The first sun gear has 11 teeth. The first planetary gear has 12 teeth. The module of the 10 gear in the left meshing pair is... The helix angle of the pitch circle of gear 10 in the left meshing pair; The second planetary gear has 22 teeth. The second sun gear has 21 teeth. The module of the 20 gear in the right meshing pair is... The helix angle of the pitch circle of the 20 gear in the right meshing pair; , , , All are positive integers and satisfy: .

[0026] Compared to existing technologies, by using multiple sets of rigidly coaxially connected first planetary gears 12 and second planetary gears 22 to replace the traditional independent planetary gear sets, the number of parts is significantly reduced, the overall size of the differential mechanism is compressed, the compact design requirements of the forming press are met, the assembly process complexity is reduced, and the excessive accumulation of transmission clearances is avoided from affecting transmission stability. At the same time, it takes into account the dual use requirements of high-speed idle stroke and low-speed heavy-duty pressing of the press. Furthermore, by using the equal center distance tooth matching constraint formula, the center distance of the left and right meshing pairs is ensured to be completely consistent, thereby solving the problem of planetary gear assembly interference and achieving higher overall transmission coaxiality.

[0027] Specifically, when applied to the operation of a molding press, the differential mechanism is set with two standard operating conditions: First, the second sun gear 21 is locked, and power is input through the first sun gear 11, causing the planetary differential gear 40 to rotate and output low-speed, high-torque power, which is adapted to the pressing stroke of the molding press and can achieve stable compaction molding through high torque output; Second, the first sun gear 11 is locked, and power is input through the second sun gear 21, causing the planetary differential gear 40 to rotate and output high-speed power, which is adapted to the rapid reset of the molding press during the idle stroke and can shorten the standby cycle through high-speed output.

[0028] Furthermore, with the second sun gear 21 locked, when the first sun gear 11 is used as input, the ratio of the rotational speed of the planetary differential carrier 40 to the rotational speed of the first sun gear 11 is: When the first sun gear 11 is locked and the second sun gear 21 is used as input, the ratio of the rotational speed of the planetary differential carrier 40 to the rotational speed of the second sun gear 21 is: in: The rotational speed of the first sun gear 11, The rotational speed of the second sun gear 21 The planetary differential gear operates at 40 RPM.

[0029] Furthermore, when the planetary differential gear 40 is fixed, the first sun gear 11, the first planet gear 12, the second planet gear 22, and the second sun gear 21 form a fixed-axis gear train, which can realize transmission with the same rotation direction but different speeds, so that when the differential mechanism is used as a transmission mechanism, it can realize the speed adjustment of the transmission. The transmission ratio with the first sun gear 11 as input and the second sun gear 21 as output. for: A growth rate can be achieved.

[0030] The transmission ratio with the second sun gear 21 as input and the first sun gear 11 as output. for: It can achieve deceleration.

[0031] Example 1 of tooth fitting: Let L = 54 mm, = =0, Under the condition that the meshing conditions are met, the gears are matched as follows: Example 2 of tooth fitting: Let L = 54 mm, = =0, Under the condition that the meshing conditions are met, the gears are matched as follows: Example 3 of tooth fitting: Let L = 54 mm, = =0, Under the condition that the meshing conditions are met, the gears are matched as follows: Furthermore, the number of the first planetary gear 12 and the second planetary gear 22 is N, where N is also the number of teeth on the first sun gear 11. The second sun gear has 21 teeth. The greatest common divisor of the number of teeth on the first sun gear (11 teeth). The second sun gear has 21 teeth. When multiple common divisors exist, N can be chosen in several ways, among which N is preferred. 3. For example, when the first sun gear has 11 teeth... The second sun gear has 21 teeth. When both common factors 3 and 4 exist, three sets of first planetary gears 12 and second planetary gears 22 can be set, or four sets of first planetary gears 12 and second planetary gears 22 can be set.

[0032] Furthermore, in order to further eliminate assembly gaps and improve structural rigidity and impact resistance, each pair of first planetary gears 12 and second planetary gears 22 are integrally formed and rotatably mounted in the planetary differential carrier 40 via a rotating shaft. The planetary differential carrier 40 is an integrally formed cage structure with multiple openings 41 on its four side walls, through which the planetary differential carrier 40 can be inserted.

[0033] Furthermore, the number of openings 41 is the same as the number of first planetary gears 12 and second planetary gears 22. In order to improve structural rigidity and impact resistance, the planetary differential carrier 40 can be provided with a thicker wall. The outer sides of the first planetary gears 12 and / or the second planetary gears 22 are partially located in the openings 41. That is, the outer sides of the first planetary gears 12 and / or the second planetary gears 22 extend outward into the openings 41. This allows for increasing the wall thickness of the planetary differential carrier 40 while avoiding increasing the overall volume of the differential mechanism.

[0034] Furthermore, the first sun gear 11 and the second sun gear 21 are each integrally formed with a transmission shaft 31, and the outer end of the transmission shaft 31 is provided with a transmission spline 32. The first sun gear 11 and the second sun gear 21 are respectively connected to different motors through the transmission shaft 31 and the transmission spline 32.

[0035] As attached Figure 7-10 As shown, a speed reducer includes the aforementioned differential mechanism and a speed reduction mechanism; the upper part of the speed reduction mechanism is provided with an input drive shaft 51, and an input drive end gear 52 is keyed to the input drive shaft 51. A bevel gear 42 is coaxially keyed to one side of the planetary differential gear 40, and the bevel gear 42 meshes with the input drive end gear plate 52.

[0036] Compared to existing technologies, by using multiple sets of rigidly coaxially connected first planetary gears 12 and second planetary gears 22 to replace the traditional independent planetary gear sets, the number of parts is significantly reduced, the overall size of the differential mechanism and reducer is compressed, the transmission link is shortened, and the transmission loss is reduced. This meets the requirements of compact design for forming presses, reduces the complexity of assembly processes, avoids excessive accumulation of transmission clearances affecting transmission stability, and simultaneously meets the dual usage requirements of high-speed idle stroke and low-speed heavy-load pressing of the press. Furthermore, by using the equal center distance gear matching constraint formula, the center distance of the left and right meshing pairs is ensured to be completely consistent, thereby solving the problem of planetary gear assembly interference and achieving higher overall transmission coaxiality.

[0037] Furthermore, in order to improve the structural compactness of the reducer, the input transmission end gear disk 52 includes a disk base 53 and arc end face teeth 54 arranged on the disk base 53, and the bevel gear 42 is an arc bevel gear. A receiving space is formed above the disk base 53, and the lower part of the planetary differential carrier 40 is placed in the receiving space. That is, with the axis of the input transmission end gear disk 52 as the projection direction, the planetary differential carrier 40 is located within the inner circle of a circle of arc end face teeth 54.

[0038] Furthermore, the reducer also includes an upper housing 61 and a lower housing 63, which are isolated from each other. The differential mechanism is located in the upper housing 61, the reduction mechanism is located in the lower housing 63, the input drive shaft 51 extends upward through the lower housing 63, and the input drive end gear 52 is located in the upper housing 61. The upper housing 61 is provided with a mounting base 62, and the planetary differential frame 40 is rotatably mounted in the upper housing 61 via the mounting base 62.

[0039] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A differential mechanism, characterized in that, include: The left meshing pair (10) includes a first sun gear (11) and a first planet gear set, wherein the first planet gear set includes multiple sets of first planet gears (12) that mesh with the first sun gear (11). The right-side meshing pair (20) includes a second sun gear (21) and a second planetary gear set, wherein the second planetary gear set includes multiple sets of second planetary gears (22) that mesh with the second sun gear (21). The planetary differential carrier (40) has the first planetary gear (12) and the second planetary gear (22) rigidly coaxially connected one-to-one and rotatably mounted in the planetary differential carrier (40); The center distance between the first sun gear (11) and the first planet gear (12) and the center distance between the second sun gear (21) and the second planet gear (22) is L. The relationship between the external meshing center distances of the gears is as follows: The formula for tooth matching constraint is: in: The number of teeth of the first sun gear (11) The number of teeth of the first planetary gear (12) The module of the left meshing pair (10) gear is... The pitch circle helix angle of the left meshing pair (10) gear; For the number of teeth of the second planetary gear (22), The number of teeth of the second sun gear (21) The module of the right-side meshing pair (20) gear is... The helix angle of the pitch circle of the right-side meshing pair (20) gear; , , , All are positive integers and satisfy: .

2. The differential mechanism according to claim 1, characterized in that, When the second sun gear (21) is locked and the first sun gear (11) is used as input, the ratio of the rotational speed of the planetary differential (40) to the rotational speed of the first sun gear (11) is: When the first sun gear (11) is locked and the second sun gear (21) is used as input, the ratio of the rotational speed of the planetary differential (40) to the rotational speed of the second sun gear (21) is: in: The rotational speed of the first sun gear (11) The rotational speed of the second sun gear (21), The rotational speed of the planetary differential (40) is given.

3. The differential mechanism according to claim 1, characterized in that, When the planetary differential gear (40) is fixed, the first sun gear (11), the first planet gear (12), the second planet gear (22), and the second sun gear (21) form a fixed-axis gear train; The transmission ratio with the first sun gear (11) as input and the second sun gear (21) as output. for: The transmission ratio with the second sun gear (21) as input and the first sun gear (11) as output. for:

4. The differential mechanism according to claim 1, characterized in that, The number of the first planetary gear (12) and the second planetary gear (22) is N, where N is also the number of teeth of the first sun gear (11). Number of teeth of the second sun gear (21) The common divisor of .

5. The differential mechanism according to claim 1, characterized in that, Each pair of first planetary gears (12) and second planetary gears (22) are integrally formed. The planetary differential frame (40) is an integrally formed cage structure with multiple openings (41) on its four side walls.

6. The differential mechanism according to claim 5, characterized in that, The number of openings (41) is the same as the number of first planetary gears (12) and second planetary gears (22), with the outer sides of the first planetary gears (12) and / or the second planetary gears (22) partially located in the openings (41).

7. The differential mechanism according to claim 1, characterized in that, The first sun gear (11) and the second sun gear (21) are each integrally formed with a transmission shaft (31), and the outer end of the transmission shaft (31) is provided with a transmission spline (32).

8. A speed reducer, characterized in that, The differential mechanism includes any one of claims 1 to 7, and further includes a reduction mechanism; the reduction mechanism is provided with an input drive shaft (51) on its upper part, and an input drive end gear disk (52) is keyed to the input drive shaft (51). The planetary differential (40) is coaxially keyed with a bevel gear (42), which meshes with the input transmission end gear plate (52).

9. The reducer according to claim 8, characterized in that, The input transmission end gear disk (52) includes a disk base (53) and arc end face teeth (54) arranged on the disk base (53), and the bevel gear (42) is an arc bevel gear; An accommodating space is formed above the disk base (53), and the lower part of the planetary differential frame (40) is placed into the accommodating space.

10. The reducer according to claim 8, characterized in that, It also includes an upper housing (61) and a lower housing (63), wherein the differential mechanism is disposed in the upper housing (61) and the deceleration mechanism is disposed in the lower housing (63); The upper housing (61) is provided with a mounting base (62), and the planetary differential gear (40) is rotatably mounted in the upper housing (61) through the mounting base (62).

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