Speed reducer output shaft structure

Abstract

This utility model discloses a reducer output shaft structure, belonging to the field of reducer technology. This reducer output shaft structure is located inside the reducer body, which includes an output shaft. A four-stage planetary carrier is externally connected to the output shaft. The four-stage planetary carrier includes a carrier plate with a spline groove inside. The output shaft includes a shaft body with a splined section at one end, which meshes with the spline groove in the carrier plate. A locking nut is located in the middle of the shaft body, and a bearing is located below the locking nut, fitted onto the shaft body. The outer ring of the bearing is connected to the upper housing of the reducer. Through the meshing of the splined section and spline groove, utilizing the advantages of the large number of spline teeth and large contact area, torque is distributed to multiple tooth surfaces, significantly improving load-bearing capacity. Simultaneously, the automatic centering function of the spline ensures the coaxiality of the output shaft and the four-stage planetary carrier, reducing additional stress caused by eccentricity and lowering the risk of output shaft breakage.

Description

Technical Field

[0001] This utility model relates to the field of speed reducers, and more specifically, to a speed reducer output shaft structure. Background Technology

[0002] In the field of industrial transmission, the speed reducer is the core equipment for realizing power transmission and speed regulation. The stability of its output shaft structure directly determines the reliability and service life of the whole machine.

[0003] Currently, heavy-duty reducers such as the PH800 are prone to insufficient centering accuracy in the fit between the output shaft and the four-stage planetary carrier during long-term operation. This can lead to additional radial forces due to assembly concentricity deviations, causing the output bearing to bend or even break under alternating loads. Furthermore, the lack of a proper transition structure at the mating points between the planetary carrier and the output shaft makes tooth collisions easy during assembly, resulting in significant local stress concentration during transmission and exacerbating spline wear. Additionally, the axial positioning structure of shaft components (such as bearings and planetary carriers) is loose, making them prone to movement, leading to increased transmission clearance and decreased torque transmission efficiency. Therefore, inventing a reducer output shaft structure to improve these problems has become a pressing issue for those skilled in the art. Utility Model Content

[0004] To overcome the above shortcomings, this utility model provides a reducer output shaft structure, which aims to improve the problems that are easy to cause insufficient centering accuracy in the fit between the output shaft and the four-stage planetary carrier, easy tooth collision during assembly, loose axial positioning structure, and easy movement.

[0005] This utility model is implemented as follows: a reducer output shaft structure is located inside the reducer body. The reducer body includes an output shaft, and a four-stage planetary carrier is externally connected to the output shaft. The four-stage planetary carrier includes a carrier plate, and a spline groove is formed inside the carrier plate. The output shaft includes a shaft body, and a spline segment is provided at one end of the shaft body. The spline segment meshes with the spline groove in the carrier plate. A locking nut is provided in the middle of the shaft body, and a bearing is provided below the locking nut. The bearing is sleeved on the shaft body, and the outer ring of the bearing is connected to the upper housing of the reducer.

[0006] In a preferred embodiment of this utility model, a through hole is provided in the middle of the frame plate, and a spline groove is located in the through hole, with the spline groove engaging with the spline segment.

[0007] In a preferred embodiment of this utility model, the support plate has a milling groove on one side of the spline groove, the depth of the milling groove is 7.5mm, and the diameter of the milling groove is 78mm.

[0008] In a preferred embodiment of this utility model, the outer edge of the milling groove is provided with an outer chamfer, and an inner chamfer is provided between the milling groove and the spline groove.

[0009] In a preferred embodiment of this utility model, a collar is provided above the spline segment of the shaft body, and the collar is in limiting contact with the upper part of the frame plate.

[0010] In a preferred embodiment of this utility model, the shaft body is provided with a journal above the shaft collar, the bearing is sleeved on the journal, and the lower part of the bearing abuts against the upper part of the shaft collar.

[0011] In a preferred embodiment of this utility model, the shaft body is provided with a threaded section above the journal, and a locking nut is sleeved on the outside of the threaded section. The lower part of the locking nut abuts against the upper part of the inner ring of the bearing.

[0012] In a preferred embodiment of this utility model, the locking nut is a precision locking nut, and the thickness of the locking nut is 18mm.

[0013] The beneficial effects of this utility model are as follows: The output shaft structure of the reducer obtained by the above design improves transmission stability and load-bearing capacity during use. By meshing the spline section and spline groove, the torque is distributed to multiple tooth surfaces by taking advantage of the large number of spline teeth and the large contact area, which significantly improves the load-bearing capacity. At the same time, the automatic centering function of the spline can ensure the coaxiality of the output shaft and the fourth-stage planetary carrier, reduce the additional stress caused by eccentricity, and reduce the risk of output shaft breakage.

[0014] Optimize axial positioning accuracy: The three-level positioning structure, in which the collar abuts against the top of the frame plate, the bearing abuts against the bottom of the collar plate, and the lock nut abuts against the inner ring of the bearing, forms a rigid constraint chain from top to bottom, which completely restricts the axial movement of the frame plate and bearing, and ensures the stability of the relative positions of each component.

[0015] Reduce assembly difficulty and stress concentration: The milled groove provides guiding space for the insertion of the spline section, the outer chamfer can avoid the edge of the frame plate and the output shaft from bumping during assembly, and the inner chamfer optimizes the transition area between the milled groove and the spline groove, reduces stress concentration points, and extends the service life of the frame plate.

[0016] Ensuring bearing reliability: The bearing is fitted onto a special journal, and the axial clamping with a precision locking nut ensures a tight fit between the inner ring of the bearing and the journal. At the same time, the outer ring is fixed to the upper housing, achieving a stable support form of "inner ring rotates with the shaft, outer ring is fixed", reducing the rotational friction and radial runout of the output shaft. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of one side of the structure provided by an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the internal structure provided for an embodiment of this utility model;

[0020] Figure 3 A schematic diagram of the output shaft structure provided for an embodiment of this utility model;

[0021] Figure 4 A schematic diagram of a four-stage planetary carrier structure provided for an embodiment of this utility model.

[0022] In the diagram: 100 - Gearbox body; 110 - Four-stage planetary carrier; 111 - Carrier plate; 112 - Spline groove; 113 - External chamfer; 114 - Milled groove; 115 - Internal chamfer; 120 - Output shaft; 121 - Shaft body; 122 - Shaft shoulder; 123 - Threaded section; 124 - Splined section; 125 - Bearing; 126 - Locking nut; 127 - Journal; 128 - Shaft collar. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0024] Please see Figure 1 and Figure 2This utility model provides a technical solution: a reducer output shaft structure located inside the reducer body 100. The reducer body 100 includes an output shaft 120, and a four-stage planetary carrier 110 is externally connected to the output shaft 120. The four-stage planetary carrier 110 includes a carrier plate 111, and a spline groove 112 is formed inside the carrier plate 111. The output shaft 120 includes a shaft body 121, and a spline section 124 is provided at one end of the shaft body 121. The spline section 124 meshes with the spline groove 112 in the carrier plate 111. The middle part of the shaft body 121 is provided with... A locking nut 126 is provided, and a bearing 125 is provided below the locking nut 126. The bearing 125 is sleeved on the shaft body 121, and the outer ring of the bearing 125 is connected to the upper housing of the reducer. Through the meshing of the spline section 124 and the spline groove 112, the torque is distributed to multiple tooth surfaces by taking advantage of the large number of spline teeth and the large contact area, which significantly improves the load-bearing capacity. At the same time, the automatic centering function of the spline can ensure the coaxiality of the output shaft 120 and the fourth-stage planetary carrier 110, reduce the additional stress caused by eccentricity, and reduce the risk of breakage of the output shaft 120.

[0025] Please see Figure 3 and Figure 4 A lower bearing is added to the lower housing of the reducer body 100 at the lower end of the output shaft 120. The lower bearing is sleeved with the lower end of the output shaft 120, which can further improve the stability of the output shaft 120 during operation and reduce radial runout. At the same time, the bearing grease is applied to the mating part between the output shaft 120 and the lower bearing to reduce friction loss and extend the service life of the lower bearing. In addition, a wear-resistant coating is applied to the inner wall of the mounting hole where the upper housing of the reducer mates with the outer ring of the bearing 125. This can enhance the wear resistance of the mounting hole and prevent the bearing 125 from shifting due to wear after long-term use, thus ensuring transmission accuracy.

[0026] The fourth-stage planetary carrier 110 is located inside the gearbox body 100.

[0027] A through hole is provided in the middle of the frame plate 111, and the spline groove 112 is located in the through hole. The spline groove 112 meshes with the spline segment 124. The surface roughness of the spline groove 112 is controlled below Ra0.8μm, and the surface roughness of the spline segment 124 is also controlled below Ra0.8μm. This can reduce the surface friction during spline meshing, reduce the wear rate, and improve the torque transmission efficiency. It is recommended to apply extreme pressure gear oil to the meshing part of the spline groove 112 and the spline segment 124 to form an effective oil film, enhance the lubrication effect, prevent failure phenomena such as tooth surface scuffing and pitting, and extend the service life of the spline fit.

[0028] The support plate 111 has a milled groove 114 on one side of the spline groove 112. The milled groove 114 has a depth of 7.5 mm and a diameter of 78 mm. The roughness of the inner wall of the milled groove 114 is controlled at Rz1.6μm, which meets the processing requirements and can reduce the obstruction during assembly. At the same time, a rounded corner of R1mm is set at the bottom of the milled groove 114 to avoid stress concentration and prevent cracks from appearing at the bottom of the milled groove 114 after long-term stress. It is recommended to spray an anti-rust coating on the inner wall of the milled groove 114 to effectively prevent rust from forming on the inner wall of the milled groove 114, avoid rust affecting the normal meshing of the spline segment 124 and the spline groove 112, and ensure transmission stability.

[0029] The outer edge of the milled groove 114 is provided with an outer chamfer 113, and an inner chamfer 115 is provided between the milled groove 114 and the spline groove 112. The outer chamfer 113 is set with an angle of 45° and a chamfer width of 2mm, which can play a good guiding role during assembly, avoid collision between the bracket plate 111 and the output shaft 120 during assembly, and protect the tooth profile of the spline section 124 and the spline groove 112. The inner chamfer 115 is also set with an angle of 45° and a chamfer width of 1.5mm, which can further optimize stress distribution, reduce stress concentration at the transition part between the milled groove 114 and the spline groove 112, improve the structural strength of the bracket plate 111, and facilitate the smooth entry of the spline section 124 into the spline groove 112 during assembly.

[0030] A collar 128 is provided above the spline section 124 on the shaft body 121. The collar 128 abuts against the upper limit of the frame plate 111. The axial thickness of the collar 128 is set to 8mm and the radial height is set to 5mm, which can provide stable axial support for the frame plate 111 and ensure that the frame plate 111 will not move upward during operation. It is recommended to set a wear-resistant shim on the end face of the collar 128 in contact with the frame plate 111. The wear-resistant shim is made of polytetrafluoroethylene, which has good wear resistance and self-lubricating properties. It can reduce the friction and wear between the collar 128 and the frame plate 111, reduce the noise during operation, and improve the overall structural stability.

[0031] A journal 127 is provided above the collar 128 on the shaft body 121. The bearing 125 is sleeved on the journal 127, and the lower part of the bearing 125 abuts against the upper part of the collar 128. The diameter tolerance of the journal 127 is controlled at level h6, and the surface roughness is controlled at Ra0.4μm. This ensures a tight fit between the inner ring of the bearing 125 and the journal 127, and avoids excessive clearance that could cause the bearing 125 to wobble during operation. It is recommended to perform carburizing and quenching treatment on the surface of the journal 127, with a carburizing layer depth of 0.8-1.2mm and a surface hardness of HRC58-62. This can significantly improve the surface hardness and wear resistance of the journal 127, extend the service life of the fit between the journal 127 and the bearing 125, and enhance the fatigue strength of the journal 127.

[0032] The shaft body 121 has a threaded section 123 above the journal 127. A lock nut 126 is fitted onto the outside of the threaded section 123. The lower part of the lock nut 126 abuts against the upper part of the inner ring of the bearing 125. The thread precision grade of the threaded section 123 is set to 5g to ensure a precise fit between the lock nut 126 and the threaded section 123, and to prevent the lock nut 126 from loosening due to excessive thread clearance. It is recommended to apply thread-locking adhesive, such as Loctite thread-locking adhesive, to the surface of the threaded section 123 with a thickness of 0.1-0.2mm. This can effectively prevent the lock nut 126 from loosening due to vibration during the operation of the reducer, ensure the axial positioning stability of the bearing 125, and facilitate subsequent disassembly and maintenance.

[0033] Locking nut 126 is a precision locking nut with a thickness of 18mm. It is made of 42CrMoA material, heat-treated to achieve a hardness of HB220-250, providing excellent strength and toughness, and capable of withstanding significant axial locking forces without deformation. It is recommended to add anti-slip grooves to the upper surface of locking nut 126. The grooves should be 0.5mm deep, 1mm wide, and 2mm apart. This will increase friction during installation and removal, facilitating tightening or loosening with tools and improving operational convenience.

[0034] Working principle: Power transmission path: After the fourth-stage planetary carrier 110 obtains power through the planetary gears, it transmits the power to the spline section 124 of the output shaft 120 through the spline groove 112 in the through hole in the middle of the carrier plate 111. The spline meshing achieves torque transmission without relative rotation, and finally the output shaft 120 outputs the power outward.

[0035] Axial positioning constraint: The collar 128 is located above the spline section 124 and abuts against the top of the bracket plate 111 to restrict its upward movement; the bearing 125 is sleeved on the journal 127 above the collar 128 and abuts against the collar 128 below; after the lock nut 126 is tightened through the threaded section 123, it abuts against the top of the inner ring of the bearing 125 below, axially locking the bearing 125, thereby indirectly strengthening the positioning stability of the bracket plate 111 through the collar 128.

[0036] The auxiliary structure functions as follows: the milled groove 114 (78mm in diameter and 7.5mm in depth) on the bracket plate 111 provides clearance for the insertion of the spline section 124, the outer chamfer 113 guides the bracket plate 111 to smoothly fit into the output shaft 120, and the inner chamfer 115 optimizes the stress distribution in the transition area of ​​the groove; the outer ring of the bearing 125 is connected to the upper housing to provide radial support for the output shaft 120 and reduce shaking during rotation.

[0037] It should be noted that the specific model and specifications in this solution need to be selected and determined based on the actual specifications of the device. The specific selection and calculation method adopts the existing technology in this field, so it will not be described in detail here.

[0038] The power supply and its principle in this solution are clear to those skilled in the art, and will not be described in detail here.

[0039] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A reducer output shaft structure, located inside the reducer body, characterized in that, The reducer body includes an output shaft, and a four-stage planetary carrier is externally connected to the output shaft. The four-stage planetary carrier includes a carrier plate, and a spline groove is formed inside the carrier plate. The output shaft includes a shaft body, and a spline section is provided at one end of the shaft body. The spline section meshes with the spline groove in the carrier plate. A locking nut is provided in the middle of the shaft body, and a bearing is provided below the locking nut. The bearing is sleeved on the shaft body, and the outer ring of the bearing is connected to the upper housing of the reducer.

2. The reducer output shaft structure as described in claim 1, characterized in that: The frame plate has a through hole in the middle, and a spline groove is located in the through hole. The spline groove and the spline segment are engaged.

3. The reducer output shaft structure as described in claim 2, characterized in that: The frame plate has a milled groove on one side of the spline groove. The depth of the milled groove is 7.5 mm and the diameter of the milled groove is 78 mm.

4. The reducer output shaft structure as described in claim 3, characterized in that: The outer edge of the milling groove is provided with an outer chamfer, and an inner chamfer is provided between the milling groove and the spline groove.

5. The reducer output shaft structure as described in claim 3, characterized in that: A collar is provided above the spline section of the shaft body, and the collar abuts against the upper limit of the frame plate.

6. The reducer output shaft structure as described in claim 5, characterized in that: The shaft body is provided with a journal above the collar, the bearing is sleeved on the journal, and the lower part of the bearing abuts against the upper part of the collar.

7. The reducer output shaft structure as described in claim 6, characterized in that: The shaft body has a threaded section above the journal, and a locking nut is sleeved on the outside of the threaded section. The lower part of the locking nut abuts against the upper part of the inner ring of the bearing.

8. The reducer output shaft structure as described in claim 7, characterized in that: The locking nut is a precision locking nut, and the thickness of the locking nut is 18mm.

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