A two-stage reduction device

Abstract

The utility model relates to the technical field of speed reducer discloses a two-stage speed reduction device, wherein the first small diameter gear is engaged with the first big diameter gear, the second small diameter gear is engaged with the second big diameter gear, the axial height of the first small diameter gear is higher than the axial height of the second big diameter gear, the first big diameter gear and the second small diameter gear rotate coaxially with the intermediate shaft body, and the speed reduction transmission from the input shaft body to the output shaft body is realized through the meshing transmission of the first gear set and the second gear set, the utility model changes the arrangement position of the first gear set for realizing the first-stage speed reduction and the second gear set for realizing the two-stage speed reduction, sets up the axial height of the first small diameter gear higher than the second big diameter gear, shortens the cantilever of the second big diameter gear, and supports the bearing seat below the first small diameter gear to increase the rigidity, makes the whole two-stage speed reduction device load shaking amount small, avoids the tooth surface abrasion, the whole structure of the device is compact, and the operation stability is high.

Description

Technical Field

[0001] This utility model relates to the field of speed reducer technology, and in particular to a two-stage speed reduction device. Background Technology

[0002] Two-stage reduction gears, as a power transmission component, are widely used in various mechanical equipment. Their main function is to convert high-speed, low-torque input power into low-speed, high-torque output power through the meshing of two-stage gears, so as to meet the specific torque and speed requirements of different mechanical equipment during operation.

[0003] Existing two-stage reduction gears typically have a lower-end pinion on the first shaft, a top-smaller, bottom-larger double gear on the second shaft, and a top-mounted main gear on the third shaft. This layout results in an excessively long cantilever for the third-shaft main gear and insufficient shaft rigidity. During operation, the lack of sufficient support for the cantilever makes it prone to significant deformation, leading to excessive swaying of the entire two-stage reduction gear under load. This not only reduces the stability and reliability of the equipment but may also decrease the meshing precision between gears, accelerate gear wear, and shorten the equipment's lifespan. Utility Model Content

[0004] The purpose of this invention is to provide a two-stage reduction gear to solve the problems in the prior art, shorten the cantilever length of the three-axis main gear, reduce the load sway of the two-stage reduction gear, and increase the reliability of the device.

[0005] This utility model provides a two-stage reduction gear, including a base, on which an input shaft, an intermediate shaft, and an output shaft are rotatably connected. It also includes a first gear set for achieving first-stage reduction and a second gear set for achieving second-stage reduction, wherein: The first gear set includes a first minor diameter gear axially connected to the input shaft and a first major diameter gear axially connected to the intermediate shaft, wherein the first minor diameter gear and the first major diameter gear are meshed together. The second gear set includes a second minor diameter gear axially connected to the intermediate shaft and a second major diameter gear axially connected to the output shaft, wherein the second minor diameter gear and the second major diameter gear are meshed together. The axial height of the first minor diameter gear is higher than that of the second major diameter gear. The first major diameter gear and the second minor diameter gear rotate coaxially with the intermediate shaft. The deceleration transmission from the input shaft to the output shaft is achieved through the meshing of the first gear set and the second gear set.

[0006] In the two-stage reduction gear described above, preferably, a bearing seat is provided on the base, and the upper end face of the bearing seat abuts against the lower end face of the first small diameter gear to form radial support for the first small diameter gear.

[0007] In the two-stage reduction gear described above, preferably, the bearing housing and the base are connected by fastening bolts, which pass through the upper end face of the base and extend downward.

[0008] In the two-stage reduction device described above, preferably, a reducer output shaft is provided on the side of the base opposite to the first small diameter gear, and the input shaft is coaxially connected to the reducer output shaft.

[0009] In the two-stage reduction gear described above, preferably, the base is further provided on one side of the vertically opposite side of the base, the output shaft extends axially to the base, the base is embedded with a deep groove ball bearing, and the output shaft passes through the deep groove ball bearing.

[0010] In the two-stage reduction device described above, preferably, a fixing component is provided on the side of the base away from the second large-diameter gear. The fixing component includes a half-bearing housing and a half-bearing bush. The half-bearing bush is detachably connected to the half-bearing housing, and the half-bearing housing is fixedly connected to the base. The half-bearing housing and the half-bearing bush together form a circular cavity, and the output shaft is disposed through the circular cavity.

[0011] In the two-stage reduction gear described above, preferably, a shrink sleeve for radial transmission is provided between the output shaft and the second large-diameter gear.

[0012] In the two-stage reduction gear described above, preferably, both the first large-diameter gear and the second small-diameter gear are provided with sliding bearings, and the intermediate shaft is sequentially disposed within the two sliding bearings along the axial direction.

[0013] In the two-stage reduction device described above, preferably, gear covers are provided on the side of the first small diameter gear and the first large diameter gear facing away from the base.

[0014] Compared with the prior art, this utility model changes the traditional arrangement of the first gear set used to achieve first-stage reduction and the second gear set used to achieve second-stage reduction. The shaft center height of the first small diameter gear is set higher than that of the second large diameter gear, the cantilever of the second large diameter gear is shortened, and a bearing seat is set below the first small diameter gear to increase rigidity. This makes the overall two-stage reduction device have less load sway, avoids tooth surface wear, and the overall structure of the device is compact with high operational stability. Attached Figure Description

[0015] Figure 1 This is a perspective view of the two-stage deceleration device provided in an embodiment of this utility model; Figure 2 This is a cross-sectional view of the two-stage deceleration device provided in an embodiment of this utility model; Figure 3 This is a front view of the two-stage deceleration device provided in an embodiment of this utility model; Figure 4 yes Figure 1 Enlarged view of point A in the image; Figure 5 yes Figure 2 Enlarged view of point B in the image; Figure 6 yes Figure 3 Enlarged view of point C in the image; Figure 7 This is a partial cross-sectional view of the two-stage deceleration device provided in an embodiment of this utility model.

[0016] Explanation of reference numerals in the attached figures: 10. Base; 11. Bearing housing; 12. Fastening bolts; 13. Reducer output shaft; 14. Base; 15. Deep groove ball bearing; 20. Input shaft; 21. First minor diameter gear; 22. Gear cover; 30. Intermediate shaft; 31. First major diameter gear; 32. Second minor diameter gear; 33. Sliding bearing; 40. Output shaft; 41. Second major diameter gear; 42. Expansion sleeve; 50. Fixing component; 51. Half bearing housing; 52. Half bearing shell; 53. Circular chamber. Detailed Implementation

[0017] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] See Figure 1 and Figure 5 As shown, this embodiment provides a two-stage reduction gear, including a base 10, on which an input shaft 20, an intermediate shaft 30, and an output shaft 40 are rotatably connected. It also includes a first gear set for achieving first-stage reduction and a second gear set for achieving second-stage reduction, wherein: The first gear set includes a first minor diameter gear 21 axially connected to the input shaft 20 and a first major diameter gear 31 axially connected to the intermediate shaft 30. The first minor diameter gear 21 and the first major diameter gear 31 are meshed together. The second gear set includes a second minor diameter gear 32 axially connected to the intermediate shaft 30 and a second major diameter gear 41 axially connected to the output shaft 40. The second minor diameter gear 32 and the second major diameter gear 41 are meshed together. The axial height of the first minor diameter gear 21 is higher than that of the second major diameter gear 41. The first major diameter gear 31 and the second minor diameter gear 32 rotate coaxially with the intermediate shaft 30. The deceleration transmission from the input shaft 20 to the output shaft 40 is achieved through the meshing transmission of the first gear set and the second gear set.

[0019] See Figure 2-3 As shown, in this embodiment, the input shaft 20 is heightened so that the axis of the first minor diameter gear 21 is higher than that of the second major diameter gear 41. This makes the meshing position of the second major diameter gear 41 and the second minor diameter gear 32 closer to the base 10, significantly shortening the cantilever length of the output shaft 40, reducing shaft deflection and vibration, and reducing the load sway of the overall two-stage reduction device. The first major diameter gear 31 and the second minor diameter gear 32 on the intermediate shaft 30 can be shortened by reasonably designing the axial spacing, while ensuring that the meshing does not interfere, further compressing the overall size of the device and making the layout more compact.

[0020] The cantilever at the second large diameter gear 41 is shortened, which improves the rigidity of this side and reduces the deformation of the shaft under load. However, after the position of the first small diameter gear 21 is raised, the rigidity of this side decreases. Therefore, in this embodiment, a bearing seat 11 is provided on the base 10. The upper end face of the bearing seat 11 abuts against the lower end face of the first small diameter gear 21 to form radial support for the first small diameter gear 21 and increase the rigid connection of the input shaft 20.

[0021] See Figure 3-4As shown, in existing two-stage reduction gears, the input shaft 20 and the first minor diameter gear 21 are arranged at the lower end, with the first minor diameter gear 21 close to the base 10. When assembling it with the base 10 via a connector, the bolts must be installed in reverse from the lower end of the base 10 to avoid the first minor diameter gear 21. However, other components are located at the lower end of the base 10, resulting in a narrow space and obstructions. When installing the bolts in reverse, operations such as insertion, alignment, and tightening must be completed within the confined space, making assembly difficult. In this embodiment, the first minor diameter gear 21 is raised and supported by a bearing housing 11. Therefore, in this embodiment, the bearing housing 11 and the base 10 are connected by a fastening bolt 12, which penetrates from the upper surface of the base 10 and extends downwards. The bearing housing 11 is installed face-up when connected to the base 10, with the bolt installed vertically downwards along the upper surface of the base 10. The path is clear and far from the lower components, avoiding interference with other structures and reducing the assembly error rate. Furthermore, the bearing housing 11 can penetrate from the lower end of the base 10 and extend to the upper end surface of the base 10. The fixing part of the bearing housing 11 fits against the lower end of the base 10, reducing the space occupied by the bearing housing 11 and increasing the stability of the device.

[0022] See Figure 3 and Figure 6 As shown, in this embodiment, a reducer output shaft 13 is provided on the side of the base 10 opposite to the first minor diameter gear 21, and the input shaft 20 is coaxially connected to the reducer output shaft 13. The input shaft 20 and the reducer output shaft 13 are coaxially connected within the bearing housing 11 to achieve power transmission.

[0023] See Figure 3 and Figure 6 As shown, in one feasible embodiment, a fixing component 50 is provided on the side of the base 10 away from the second large diameter gear 41. The fixing component 50 includes a half bearing seat 51 and a half bearing bush 52. The half bearing bush 52 is detachably connected to the half bearing seat 51. The half bearing seat 51 is fixedly connected to the base 10. The half bearing seat 51 and the half bearing bush 52 together form a circular cavity, and the output shaft 40 is disposed through the circular cavity.

[0024] Traditional integral bearing housings 11 require the output shaft 40 to be inserted into the bearing housing 11 from the shaft end or the bearing to be press-fitted from the shaft end. If the shaft length is long or gears or other components are pre-installed on the output shaft, the overall assembly is difficult. For example, tapered roller bearings are commonly used. These bearings are difficult to manufacture and require high coaxiality and positional accuracy during assembly. This necessitates strict control of interference fit and preload during assembly, and they are prone to damaging related components during maintenance, further increasing the difficulty of assembly and maintenance. In this embodiment, the half-bearing housing 51 and the half-bearing bush 52 are separate structures. The output shaft 40 can be placed in the preset position of the base 10 first, and then the half-bearing bush 52 can be fastened and fixed. Axial installation is not required, simplifying the installation process and reducing maintenance costs. The half-shaft bearing 52 can be made of wear-resistant material and is detachably connected to the half-shaft bearing housing 51. If the shaft and bearing surface experience excessive wear due to long-term operation, resulting in excessive clearance, the clearance can be compensated by replacing the half-shaft bearing 52 with one of different thicknesses. This ensures the radial positioning accuracy of the output shaft 40 and avoids shaft movement or poor gear meshing caused by excessive clearance. In addition, the sliding friction type of the half-shaft bearing 52 has a large contact area with the shaft, which can better disperse the radial force transmitted from the gear to the output shaft and reduce local stress concentration.

[0025] The existing two-stage reduction gear output shaft 40 is positioned and installed using tapered roller bearings. During assembly, the tapered roller bearings require pre-tightening to ensure the longitudinal bearing position tolerance is controlled within 0.15mm. Furthermore, the tapered roller bearing at the base 10 requires the addition of bearing adjusting shims to meet assembly requirements, and the radial hole size of the bearing at this location needs to be back-bored, again controlling the tolerance accuracy within 0.15mm. This assembly method is difficult, requires extensive assembly experience, and the output shaft 40 can only be assembled from top to bottom and disassembled from bottom to top, making disassembly and assembly inconvenient and costly. To solve these problems, see [reference needed]. Figure 2As shown, a base 14 is also provided on one side of the base 10 along the vertical direction. The output shaft 40 extends axially to the base 14, and a deep groove ball bearing 15 is embedded in the base 14. The output shaft 40 passes through the deep groove ball bearing 15. The output shaft 40 adopts a force-bearing structure in which the deep groove ball bearing 15 cooperates with the fixed component 50, which effectively disperses the radial load borne by the shaft, reduces the bending deformation of the shaft caused by cantilever force, reduces the eccentricity between the shaft and the gear, and can limit the axial movement of the shaft, thereby improving the running accuracy. The deep groove ball bearing 15 has good radial load-bearing capacity, low friction coefficient, and wide speed adaptability, making it suitable for supporting the extended end of the output shaft 40. Its structure is simple and low cost, which can reduce the complexity and cost of the overall design while ensuring support strength. In addition, the absence of hole position tolerance requirements between the half-bearing shell 52 and the deep groove ball bearing 15 makes the machining process less difficult. Furthermore, a deep groove ball bearing 15 is installed at the base 14, and a bearing limiting baffle is installed on one side of the base 14. The bearing position dimensional tolerance of the deep groove ball bearing 15 only needs to be controlled within 0.5mm. A half bearing seat 51 is installed at the base 10. The output shaft 40 can enter the assembly position from the front, rear, left and rear directions. After the position is adjusted, it is fixed to the half bearing seat 51 by the half bearing bush 52. The assembly process can be guaranteed to be reliable without the need for reverse boring. Moreover, the assembly steps are simple, the disassembly and assembly are convenient, and the assembly cost is low.

[0026] See Figure 4 As shown, the existing connection between the output shaft 40 and the second large-diameter gear 41 is usually achieved through a key connection or an interference fit. Interference fits are difficult to control and are not easy to disassemble. Key connections, typically using splines, offer high load-bearing capacity but are costly, and require strict alignment of the tooth profiles during assembly to prevent uneven loading on the tooth surface. To address this issue, in this embodiment, a shrinking sleeve 42 for radial transmission is provided between the output shaft 40 and the second large-diameter gear 41. The shrinking sleeve 42, through the radial expansion of its outer and inner sleeves, uses friction to grip the inner holes of the output shaft 40 and the second large-diameter gear 41. This eliminates the need to machine keyways, pin holes, or other structures on the shaft or gear, reducing the clearance between the shaft and gear. It also generates uniform radial pressure on the contact surfaces between the sleeve and the inner holes of the shaft and gear, ensuring minimal concentricity error between the shaft and gear, high centering accuracy, smoother transmission, and lower cost.

[0027] See Figure 5As shown, in this embodiment, both the first large-diameter gear 31 and the second small-diameter gear 32 are provided with sliding bearings 33, and the intermediate shaft 30 is sequentially disposed within the two sliding bearings 33 along the axial direction. The sliding bearings 33 do not require complex rolling elements and cages. Compared with traditional rolling bearings, the manufacturing process of the sliding bearings 33 is simpler, and the material cost is lower. The sliding bearings 33 can be used to improve the support stability of the intermediate shaft 30, reduce the radial runout of the intermediate shaft 30 during rotation, avoid gear meshing misalignment caused by shaft wobble, and effectively compensate for clearances.

[0028] See Figure 4 As shown, in this embodiment, gear covers 22 are respectively provided on the side of the first small diameter gear 21 and the first large diameter gear 31 away from the base 10. The first small diameter gear 21 and the first large diameter gear 31 are located at the upper end and belong to the first-stage reduction gear. Therefore, under high-speed rotation, impact load or vibration conditions, they are prone to slight axial movement. The covers are fixed to the shaft or adjacent components by bolts or other connecting parts. Their end faces are tightly fitted with the side of the gears to form a rigid axial constraint, restricting the axial movement of the gears and protecting them.

[0029] The assembly steps for this two-stage reduction gear are as follows: S1. Sliding bearings 33 are press-fitted onto the first large diameter gear 31 and the second small diameter gear 32, and then assembled onto the intermediate shaft 30. The intermediate shaft 30 is then assembled into the preset position of the base 10. S2. Assemble the bearing housing 11 at the preset position of the first small diameter gear 21, and fix the bearing housing 11 to the base 10 in a positive orientation; S3. Assemble the first small diameter gear 21 onto the input shaft 20, and then assemble the input shaft 20 onto the base 10. Adjust the height so that the first small diameter gear 21 meshes with the first large diameter gear 41 to ensure radial support of the bearing housing 11. S4. The deep groove ball bearing 15 is assembled to the preset position of the base 14, the half bearing housing 51 is assembled to the base 10, the output shaft 40 is assembled to the deep groove ball bearing 15, the output shaft 40 and the second large diameter gear 41 are connected by the shrink sleeve 42, the meshing clearance is adjusted to ensure the clearance between the output shaft 40 and the clearance groove, and the assembly is completed.

[0030] The above description, based on the embodiments shown in the drawings, details the structure, features, and effects of this utility model. The above description is only a preferred embodiment of this utility model, but the scope of implementation of this utility model is not limited to what is shown in the drawings. Any changes made in accordance with the concept of this utility model, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and drawings, shall be within the protection scope of this utility model.

Claims

1. A two-stage speed reduction device, comprising a base, wherein an input shaft, an intermediate shaft, and an output shaft are rotatably connected to the base, characterized in that, It also includes a first gear set for achieving first-stage reduction and a second gear set for achieving second-stage reduction, wherein: The first gear set includes a first minor diameter gear axially connected to the input shaft and a first major diameter gear axially connected to the intermediate shaft, wherein the first minor diameter gear and the first major diameter gear are meshed together. The second gear set includes a second minor diameter gear axially connected to the intermediate shaft and a second major diameter gear axially connected to the output shaft, wherein the second minor diameter gear and the second major diameter gear are meshed together. The axial height of the first minor diameter gear is higher than that of the second major diameter gear. The first major diameter gear and the second minor diameter gear rotate coaxially with the intermediate shaft. The deceleration transmission from the input shaft to the output shaft is achieved through the meshing of the first gear set and the second gear set.

2. The two-stage reduction gear according to claim 1, characterized in that, The base is provided with a bearing seat, the upper end face of which abuts against the lower end face of the first small diameter gear to provide radial support for the first small diameter gear.

3. The two-stage reduction gear according to claim 2, characterized in that, The bearing housing and the base are connected by fastening bolts, which pass through the upper end face of the base and extend downward.

4. The two-stage reduction gear according to claim 1, characterized in that, The base has a reducer output shaft on the side opposite to the first small diameter gear, and the input shaft is coaxially connected to the reducer output shaft.

5. The two-stage reduction gear according to claim 1, characterized in that, The base is also provided on one side of the vertical direction opposite to the base, the output shaft extends axially to the base, the base is embedded with a deep groove ball bearing, and the output shaft passes through the deep groove ball bearing.

6. The two-stage reduction gear according to claim 1, characterized in that, A fixing component is provided on the side of the base away from the second large diameter gear. The fixing component includes a half bearing seat and a half bearing bush. The half bearing bush is detachably connected to the half bearing seat. The half bearing seat is fixed to the base. The half bearing seat and the half bearing bush together form a circular cavity. The output shaft is disposed through the circular cavity.

7. The two-stage reduction gear according to claim 1, characterized in that, An expansion sleeve for radial transmission is provided between the output shaft and the second large-diameter gear.

8. The two-stage reduction gear according to claim 1, characterized in that, Both the first large-diameter gear and the second small-diameter gear are provided with sliding bearings, and the intermediate shaft is sequentially inserted through the two sliding bearings along the axial direction.

9. The two-stage reduction gear according to claim 1, characterized in that, The first small diameter gear and the first large diameter gear are respectively provided with gear covers on the side away from the base.

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