Gearbox ring thrust structure

Abstract

This utility model discloses a gearbox annular thrust structure, including a high-speed shaft and a low-speed shaft. A high-speed gear is mounted on the high-speed shaft, and a low-speed gear is mounted on the low-speed shaft. The high-speed gear and the low-speed gear mesh and transmit power. A pair of annular thrust structures are symmetrically located on both sides of the high-speed gear on the high-speed shaft. Each annular thrust structure includes a thrust sleeve and a thrust ring. The thrust sleeve comprises two semi-rings joined together to form a circular annular thrust sleeve. The inner diameter of the thrust ring is larger than the addendum circle of the high-speed gear. Each semi-ring of the thrust sleeve is keyed to the high-speed shaft. The thrust ring is fixed to the outer ring of the thrust sleeve. The high-speed shaft is supported on the gearbox by radial bearings, and the low-speed shaft is supported on the gearbox by radial bearings and thrust bearings. The thrust rings of the pair of annular thrust structures cooperate on both sides of the high-speed gear to transmit axial force. This utility model's annular thrust structure has a simple structure, reducing manufacturing costs.

Description

Technical Field

[0001] This utility model relates to the field of steam compressor technology, and in particular to a gearbox annular thrust structure. Background Technology

[0002] Steam compressors are widely used in industries such as high-concentration wastewater concentration and zero discharge, concentration and crystallization purification in the food and pharmaceutical industries, and concentration and crystallization purification in the chemical industry. Especially in MVR (Mechanical Vapor Recompression) systems, they utilize the secondary steam and its energy generated by the evaporation system itself. The steam compressor compresses the secondary steam, increasing its enthalpy, and guides it into a cooling tower. The cooling water in the cooling tower circulates the waste heat material, fully utilizing the latent heat of the steam. This method has advantages such as low energy consumption, high efficiency, short cost recovery period, and no pollution. Currently, most high-speed compressors use low-speed motors driven by gearbox transmissions to drive the compression system.

[0003] The gearbox transmission system is part of the compressor system, converting low-speed input into high-speed output, which inevitably involves power loss. Many factors influence gearbox power loss, making it impossible to optimize each factor individually through parameter calculations. Therefore, optimization design can only be implemented for some of the more influential parameters. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a gearbox ring thrust structure. The ring thrust structure of this invention has a simple structure and reduces manufacturing costs.

[0005] The purpose of this utility model is achieved as follows:

[0006] A gearbox annular thrust structure includes a high-speed shaft and a low-speed shaft. A high-speed gear is mounted on the high-speed shaft, and a low-speed gear is mounted on the low-speed shaft. The high-speed gear and the low-speed gear mesh and drive each other. A pair of annular thrust structures are provided on the high-speed shaft, symmetrically located on both sides of the high-speed gear. Each annular thrust structure includes a thrust sleeve and a thrust ring. The thrust sleeve includes two half-rings, which are joined together to form a circular thrust sleeve. The inner diameter of the thrust ring is larger than the addendum circle of the high-speed gear. Each half-ring of the thrust sleeve is keyed to the high-speed shaft. The thrust ring is fixed on the outer ring of the thrust sleeve. The high-speed shaft is supported on the gearbox by a radial bearing, and the low-speed shaft is supported on the gearbox by a radial bearing and a thrust bearing. The thrust rings of the pair of annular thrust structures cooperate on both sides of the high-speed gear to transmit axial force.

[0007] Preferably, the thrust sleeve and the thrust ring are fixed by an interference fit.

[0008] Preferably, the thrust sleeve is heat-fitted onto the thrust ring.

[0009] Preferably, the high-speed shaft is provided with an annular mounting groove along the circumference, the inner ring of the thrust sleeve fits into the annular stepped mounting groove and forms axial positioning, and the outer ring of the thrust sleeve is provided with a stop, which is located outside the corresponding thrust ring and forms axial positioning of the thrust ring.

[0010] Due to the adoption of the above technical solution, the ring thrust structure of this utility model has a simple structure, is easy to assemble, and reduces manufacturing costs.

[0011] Furthermore, by adopting this utility model, the axial thrust of the high-speed shaft is transferred to the axial direction of the low-speed shaft, the rotational speed is greatly reduced, the wear of the thrust bearing is reduced, the gearbox transmission efficiency is increased, and the thrust bearing of the high-speed shaft can be directly eliminated, leaving only the radial bearing, thereby saving costs. Attached Figure Description

[0012] Figure 1 Schematic diagram of the compressor drive system;

[0013] Figure 2 Schematic diagram of the mating surface of the low-speed gear ring;

[0014] Figure 3-a: Schematic diagram of the assembly process of the ring thruster structure;

[0015] Figure 3-b: Schematic diagram of the ring thruster structure;

[0016] Figure 4 : Schematic diagram of the ring thrust structure.

[0017] Figure Labels

[0018] In the attached diagram, 1 is the low-speed shaft, 2 is the low-speed rear bearing, 3 is the low-speed front bearing, 4 is the high-speed shaft, 5 is the high-speed front bearing, 6 is the high-speed rear bearing, 7 is the ring thrust structure, 8 is the ring thrust mating surface, 71 is the thrust sleeve, 72 is the thrust ring, and 73 is the key. Detailed Implementation

[0019] A gearbox annular thrust structure includes a high-speed shaft 4 and a low-speed shaft 1. A high-speed gear is mounted on the high-speed shaft, and a low-speed gear is mounted on the low-speed shaft. The high-speed gear and the low-speed gear mesh and transmit power. A pair of annular thrust structures 7 are symmetrically located on both sides of the high-speed gear on the high-speed shaft. Each annular thrust structure includes a thrust sleeve 71 and a thrust ring 72. The thrust sleeve comprises two half-rings, which are joined to form a circular annular thrust sleeve. The inner diameter of the thrust ring is larger than the tip circle of the high-speed gear. Each half-ring of the thrust sleeve is connected to the high-speed shaft via a key 73, forming a circumferential positioning. The thrust ring is fixed on the outer ring of the thrust sleeve. The high-speed shaft is supported in the gearbox by radial bearings, and the low-speed shaft is supported in the gearbox by radial bearings and thrust bearings. The thrust rings of the pair of annular thrust structures are clamped on both sides of the high-speed gear to transmit axial force. The thrust rings and the high-speed gear are lubricated by lubricating oil.

[0020] In this embodiment, the thrust sleeve is heat-fitted onto the thrust ring, and the thrust sleeve and the thrust ring are fixed with an interference fit. An annular mounting groove is provided circumferentially on the high-speed shaft. The inner ring of the thrust sleeve fits into the annular stepped mounting groove, forming an axial positioning. A stop is provided on the outer ring of the thrust sleeve, located outside the corresponding thrust ring, forming an axial positioning of the thrust ring. In this embodiment, the gearbox is connected to the steam compressor. The high-speed gear and low-speed gear are helical gears. The direction of the aerodynamic force of the steam compressor's compression system is opposite to the direction of the gear force of the transmission system.

[0021] Specifically:

[0022] In practical industrial applications, the structure between compressor drive systems is as follows: Figure 1 As shown, helical gear transmission is used between the high-speed and low-speed shafts, resulting in smooth meshing, low impact and noise, high load-bearing capacity, and improved gear life and stability. However, it generates unstable axial thrust. Simultaneously, during compressor operation, the impeller's work in compressing steam also applies axial thrust to the shaft. Therefore, thrust bearings are included in the axial direction of both the high-speed and low-speed bearings to prevent excessive axial movement of the shafts. The use of thrust bearings further increases power loss in the gearbox transmission system, reducing its transmission efficiency. Keeping other parameters constant, changing only the speed and axial force reveals that: higher speed and greater axial force result in greater power loss from the thrust bearings, worse gearbox transmission efficiency, and a higher input power required for the same output power.

[0023] Therefore, when designing a transmission system, the direction of gear rotation is taken into priority. This ensures that the direction of the aerodynamic force in the compression system is opposite to the direction of the gear force in the transmission system, thus balancing part of the axial thrust. At the same time, a ring-shaped thrust structure is used in the axial direction of the high-speed and low-speed shafts to transfer the axial thrust of the high-speed shaft to the axial direction of the low-speed shaft. This significantly reduces the speed, decreases the wear of the thrust bearing, and increases the efficiency of the gearbox transmission. Furthermore, the thrust bearing of the high-speed shaft can be eliminated, leaving only the radial bearing, thereby saving costs.

[0024] like Figure 2 As shown, the ring thrust mating surface of the low-speed gear is directly formed on the low-speed gear: a bevel is machined at an appropriate distance at the meshing point to mate with the ring thrust structure of the high-speed shaft, and a 5-10mm flat surface is retained on the inner side of the gear to withstand the angular changes that may occur due to local stress. While maintaining a certain strength, it is permissible to reduce the weight of the low-speed gear.

[0025] like Figure 3a , 3bAs shown, the high-speed shaft thrust structure consists of several parts: a two-part thrust sleeve, a full-circle thrust ring, a transition fit between the high-speed shaft and the thrust sleeve, and an interference fit between the thrust sleeve and the thrust ring. ANSYS software is used to apply rotational speed and local axial force to the model, and the minimum interference value is ensured by checking for looseness in the thrust ring. The two-part thrust sleeve can accommodate different tooth tip circles. As long as the inner diameter of the thrust ring is designed to be larger than the tooth tip circle, the upper and lower halves of the thrust sleeve can be closed and secured to the high-speed shaft. The thrust ring passes through the gear from the left and is heat-fitted onto the right thrust sleeve, as shown in Figure 3-a. For the second group (left side), the thrust ring needs to be heated to the heat-fitting temperature and temporarily placed at the gear. After the upper and lower halves of the thrust sleeve are closed, they are pushed back in the opposite direction for assembly. To prevent the thrust sleeve from rotating relative to the high-speed shaft as it rotates, a key is used at symmetrical positions. The thrust ring mating surface adopts the same inclined surface as the low-speed shaft, and a 5-10mm flat surface is retained on the inner side of the thrust ring to withstand the angular changes that may occur due to local stress.

[0026] The ring thrust structure installed inside the gearbox, such as Figure 4 As shown, the high-speed bearing no longer bears axial force. The combined force of gear force and aerodynamic force on the high-speed shaft is transmitted to the low-speed shaft through the ring thrust structure. The low-speed shaft counteracts axial movement through the thrust bearing. The ring thrust mating surfaces are under high-speed friction and need to ensure a certain strength. The mating surfaces can be carburized and quenched. The ring thrust clearance between the mating surfaces is determined by factors such as rotational speed, lubricating oil viscosity, center distance, and speed ratio to ensure the establishment of an oil film. However, it is also necessary to prevent the given clearance from being too large, which would lead to excessive axial movement of the high-speed shaft.

[0027] Calculations were performed using DyRoBeS software, changing only the rotational speed and axial force, to observe the power loss of the high-speed shaft thrust bearing.

[0028] Table 1 Power Loss Calculation Table

[0029] Rotational speed / Rpm Axial force / N Power loss / KW Oil film thickness / um 8600 7000 10.188 75.902 8600 11000 11.665 58.756 8600 15000 12.794 48.503 12100 7000 17.277 87.320 12100 11000 19.579 67.978 12100 15000 21.306 56.337 16500 7000 27.916 98.771 16500 13000 32.712 69.948

[0030] As shown in Table 1, the power loss varies significantly under different speeds and axial forces, especially at high speeds where the thrust bearing experiences greater losses. Therefore, replacing the thrust bearing with a ring-shaped thrust structure is of great significance for reducing power loss in gear transmission systems and improving gearbox transmission efficiency.

[0031] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of this utility model.

Claims

1. A gearbox annular thrust structure, comprising a high-speed shaft and a low-speed shaft, wherein a high-speed gear is mounted on the high-speed shaft and a low-speed gear is mounted on the low-speed shaft, and the high-speed gear and the low-speed gear mesh and transmit power, characterized in that: The high-speed shaft is equipped with a pair of ring thrust structures, which are symmetrically located on both sides of the high-speed gear. Each ring thrust structure includes a thrust sleeve and a thrust ring. The thrust sleeve includes two half-rings, which are joined together to form a circular thrust sleeve. The inner diameter of the thrust ring is larger than the tooth tip circle of the high-speed gear. Each half-ring of the thrust sleeve is keyed to the high-speed shaft. The thrust ring is fixed on the outer ring of the thrust sleeve. The high-speed shaft is supported on the gearbox by a radial bearing, and the low-speed shaft is supported on the gearbox by a radial bearing and a thrust bearing. The thrust rings of the pair of ring thrust structures cooperate on both sides of the high-speed gear to transmit axial force.

2. The gearbox annular thrust structure according to claim 1, characterized in that: The thrust sleeve and the thrust ring are fixed by an interference fit.

3. The gearbox annular thrust structure according to claim 2, characterized in that: The thrust sleeve is heat-fitted onto the thrust ring.

4. The gearbox annular thrust structure according to claim 1, characterized in that: The high-speed shaft has an annular mounting groove along its circumference. The inner ring of the thrust sleeve fits into the annular stepped mounting groove and forms an axial positioning. The outer ring of the thrust sleeve has a stop, which is located outside the corresponding thrust ring and forms an axial positioning for the thrust ring.

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