A screw expander

Abstract

The present invention relates to the technical field of waste heat recovery equipment, and discloses a screw expander, including a shell, a first support assembly and a second support assembly, wherein a synchronously rotating male rotor and female rotor are arranged in the shell; the first support assembly is spaced apart on one side of the shell, and includes a first bearing box and a first support; the second support assembly is spaced apart on the other side of the shell, and includes a second bearing box and a second support. In the screw expander provided by the present invention, the shell and the first bearing box and the second bearing box are spaced apart, so that the temperature of the first bearing box and the second bearing box does not change with the change of the shell temperature. Therefore, the bearing elevations between the first support bearing, the thrust bearing and the second support bearing and the shell elevation are independent of each other and do not affect each other, thereby avoiding the problem of vibration of the unit and forced shutdown caused by the large difference in the bearing elevations at the front and rear ends of the male rotor and the female rotor during operation of the screw expander, thereby ensuring the safe operation of the screw expander unit.

Description

Technical Field

[0001] The invention relates to the technical field of waste heat recovery equipment, and in particular to a screw expander. Background Art

[0002] Screw expander is a heat engine that converts thermal energy into mechanical energy by relying on the expansion of gas volume to drive the screw rotor to rotate. Screw expander is widely used in industrial waste heat recovery, geothermal power generation, biomass power generation and other fields. It can directly drive generators and can also directly drive mechanical equipment such as pumps and fans. While ensuring safe production, it improves energy utilization and reduces environmental pollution.

[0003] At present, the support structure of the screw expander usually adopts an integrated design with its shell. As the capacity of the screw expander unit increases, the overall structural size of the screw expander also increases. The support structure is very sensitive to the steam inlet parameters of the screw expander. The bearing elevation will change with the change of the steam inlet temperature. Since the temperature at the front end of the screw expander near the steam inlet is high, and the temperature at the rear end near the exhaust is low, during operation, the front and rear bearing elevations of the screw expander rotor will be inconsistent. When the difference in the front and rear bearing elevations reaches a certain value, it will cause vibration of the screw expander unit, resulting in forced shutdown, affecting the safe operation of the screw expander unit. Summary of the invention

[0004] Based on the above problems, the purpose of the present invention is to provide a screw expander that can solve the problem of vibration of the screw expander unit caused by inconsistent front and rear bearing elevations due to changes in the shell temperature of the screw expander, thereby improving the safety of the screw expander unit.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A screw expander, comprising:

[0007] A housing, wherein a male rotor and a female rotor that rotate synchronously are disposed in the housing;

[0008] a first support assembly, arranged at intervals on one side of the housing, the first support assembly comprising a first bearing box and a first support, the first support being used to support the first bearing box, a first support bearing and a thrust bearing being arranged in the first bearing box, one end of the rotating shafts of the male rotor and the female rotor being both located in the first bearing box and supported by the first support bearing and the thrust bearing;

[0009] The second support assembly is arranged at an interval on the other side of the shell, and the second support assembly includes a second bearing box and a second support. The second support is used to support the second bearing box. A second support bearing is arranged in the second bearing box. The other ends of the rotating shafts of the positive rotor and the negative rotor are both located in the second bearing box and supported by the second support bearing.

[0010] As a preferred embodiment of the screw expander of the present invention, a front cover is provided at one end of the shell and a rear cover is provided at the other end. One end of the rotating shaft of the positive rotor and the negative rotor passes through the front cover and is supported by the first bearing box, and the other end passes through the rear cover and is supported by the second bearing box.

[0011] As a preferred embodiment of the screw expander of the present invention, it also includes a first connecting member and a second connecting member, one end of the first connecting member is connected to the first bearing box, and the other end is connected to the front cover, one end of the second connecting member is connected to the second bearing box, and the other end is connected to the rear cover.

[0012] As a preferred embodiment of the screw expander of the present invention, a first oil deflector ring is provided between the first bearing box and the rotating shaft of the male rotor and between the first bearing box and the rotating shaft of the female rotor, and a second oil deflector ring is provided between the second bearing box and the rotating shaft of the male rotor and between the second bearing box and the rotating shaft of the female rotor.

[0013] As a preferred embodiment of the screw expander of the present invention, a first steam seal is provided between the front cover and the rotating shaft of the male rotor and between the front cover and the rotating shaft of the female rotor, and a second steam seal is provided between the rear cover and the rotating shaft of the male rotor and between the rear cover and the rotating shaft of the female rotor.

[0014] As a preferred embodiment of the screw expander of the present invention, it also includes a measuring module, a control module and an alarm module. The measuring module is used to measure the rotational speed and vibration parameters of the positive rotor and the negative rotor, and send the measurement information to the control module. The control module can receive and process the measurement information, and can send instructions to the alarm module. The alarm module is used to alarm.

[0015] As a preferred embodiment of the screw expander of the present invention, the measuring module includes a speed measuring device and a vibration measuring device. The speed measuring device is arranged in the first bearing box for measuring the speed of the rotating shaft of the male rotor and the rotating shaft of the female rotor. The vibration measuring device is arranged in the second bearing box for measuring the vibration amplitude, frequency and phase of the rotating shaft of the male rotor and the rotating shaft of the female rotor.

[0016] As a preferred embodiment of the screw expander of the present invention, a first synchronous gear and a second synchronous gear meshing with each other are further provided in the second bearing box, the first synchronous gear is provided on the rotating shaft of the male rotor, and the second synchronous gear is provided on the rotating shaft of the female rotor.

[0017] As a preferred solution of the screw expander of the present invention, the first support is a flexible plate structure, and the second support is a rigid support structure.

[0018] As a preferred solution of the screw expander of the present invention, the first bearing box and the second bearing box both include a detachable upper box body and a lower box body.

[0019] The beneficial effects of the present invention are:

[0020] The screw expander provided by the present invention has a housing and a first bearing box and a second bearing box arranged at intervals; a first support bearing and a thrust bearing are arranged in the first bearing box, and the force exerted on the male rotor and the female rotor is transmitted to the first bearing box through the first support bearing and the thrust bearing, and is finally borne by the first support. The first support bearing and the thrust bearing simultaneously bear the gravity of the front end of the male rotor and the female rotor of the screw expander, as well as the pressure, disturbance force and thrust generated by the steam on the front end of the male rotor and the female rotor during operation. A second support bearing is arranged in the second bearing box, and the force exerted on the male rotor and the female rotor is transmitted to the second bearing box through the second support bearing, and is finally borne by the second support. The second support bearing simultaneously bears the gravity of the rear end of the male rotor and the female rotor of the screw expander, as well as the pressure, disturbance force and thrust generated by the steam on the rear end of the male rotor and the female rotor during operation. Compared with the prior art in which the support structure of the screw expander and its housing are designed as an integrated type, the screw expander provided by the present invention has the housing and the first bearing box and the second bearing box arranged at intervals, so that the temperature of the first bearing box and the second bearing box does not change with the change of the housing temperature. Therefore, the bearing elevations between the first support bearing, the thrust bearing and the second support bearing and the casing elevation are independent of each other and do not affect each other, thereby avoiding the problem of unit vibration and forced shutdown caused by large difference in bearing elevations at the front and rear ends of the positive rotor and the negative rotor during operation of the screw expander, thereby ensuring the safe operation of the screw expander unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0022] Figure 1is a front view of a screw expander provided in a specific embodiment of the present invention;

[0023] Figure 2 It is a top view of a screw expander provided in a specific embodiment of the present invention.

[0024] In the figure:

[0025] 1-housing; 2-first supporting assembly; 3-second supporting assembly; 4-first connecting member; 5-second connecting member;

[0026] 11-front cover; 12-rear cover;

[0027] 21-first bearing box; 22-first support; 23-first oil retaining ring; 24-first steam seal;

[0028] 211-first support bearing; 212-thrust bearing; 213-rotation speed measuring device;

[0029] 31-second bearing box; 32-second support; 33-second oil retaining ring; 34-second steam seal;

[0030] 311 - second support bearing; 312 - first synchronous gear; 313 - second synchronous gear;

[0031] 100-male rotor; 200-female rotor. DETAILED DESCRIPTION

[0032] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] like Figure 1 and Figure 2 As shown, this embodiment provides a screw expander, which includes a housing 1, a first support assembly 2 and a second support assembly 3.

[0036] Among them, a synchronously rotating male rotor 100 and a female rotor 200 are arranged in the shell 1; the first support assembly 2 is arranged at intervals on one side of the shell 1, and the first support assembly 2 includes a first bearing box 21 and a first support 22. The first support 22 is used to support the first bearing box 21, and the first bearing box 21 is provided with a first support bearing 211 and a thrust bearing 212. One end of the rotating shaft of the male rotor 100 and the female rotor 200 is located in the first bearing box 21 and supported by the first support bearing 211 and the thrust bearing 212; the second support assembly 3 is arranged at intervals on the other side of the shell 1, and the second support assembly 3 includes a second bearing box 31 and a second support 32. The second support 32 is used to support the second bearing box 31, and the second bearing box 31 is provided with a second support bearing 311. The other end of the rotating shaft of the male rotor 100 and the female rotor 200 is located in the second bearing box 31 and supported by the second support bearing 311.

[0037] The screw expander provided in this embodiment has a casing 1 and a first bearing box 21 and a second bearing box 31 arranged at intervals; a first support bearing 211 and a thrust bearing 212 are arranged in the first bearing box 21, and the force exerted on the male rotor 100 and the female rotor 200 is transmitted to the first bearing box 21 through the first support bearing 211 and the thrust bearing 212, and is finally borne by the first support 22. The first support bearing 211 and the thrust bearing 212 simultaneously bear the gravity of the front ends of the male rotor 100 and the female rotor 200 of the screw expander, as well as the pressure, disturbance force and thrust generated by steam on the front ends of the male rotor 100 and the female rotor 200 during operation. A second support bearing 311 is arranged in the second bearing box 31, and the force exerted on the male rotor 100 and the female rotor 200 is transmitted to the second bearing box 31 through the second support bearing 311, and is finally borne by the second support 32. The second support bearing 311 simultaneously bears the gravity of the rear ends of the male rotor 100 and the female rotor 200 of the screw expander, as well as the pressure, disturbance force and thrust generated by the steam on the rear ends of the male rotor 100 and the female rotor 200 during operation. Compared with the prior art in which the support structure of the screw expander and its shell are designed as an integrated type, the screw expander provided in this embodiment arranges the shell 1 and the first bearing box 21 and the second bearing box 31 at intervals, so that the temperature of the first bearing box 21 and the second bearing box 31 will not change with the change of the temperature of the shell 1. Therefore, the bearing elevations between the first support bearing 211, the thrust bearing 212 and the second support bearing 311 and the shell 1 elevation are independent of each other and do not affect each other, thereby avoiding the problem that the male rotor 100 and the female rotor 200 cause the unit to vibrate and be forced to shut down due to the large difference in the bearing elevations at the front and rear ends during the operation of the screw expander, thereby ensuring the safe operation of the screw expander unit.

[0038] It should be noted that, in this embodiment, the end where the first bearing box 21 is located is the front end of the screw expander, and the end where the second bearing box 31 is located is the rear end of the screw expander.

[0039] The screw expander provided in this embodiment preferably has a double-barrel structure as its housing 1, and the screw sleeves of the male rotor 100 and the female rotor 200 in the housing 1 are meshed with each other. The working process is roughly as follows:

[0040] The first is the intake process. After the working medium enters the inter-tooth volume of the male rotor 100 and the female rotor 200 from the air inlet at the front end of the shell 1, it pushes the male rotor 100 and the female rotor 200 to rotate synchronously, and the inter-tooth volume continues to expand. When the inter-tooth volume is completely separated from the air inlet, the intake process ends. The second is the expansion process. The gas in the inter-tooth volume continues to expand with the rotation of the male rotor 100 and the female rotor 200. When the inter-tooth volume reaches the maximum, the expansion process ends, the working medium volume expansion temperature decreases, and at the same time, power is output to the male rotor 100 and the female rotor 200 extending out of the rear end of the shell 1. Then comes the exhaust process. When the inter-tooth volume is connected to the air outlet at the rear end of the shell 1, the exhaust process begins until the inter-tooth volume is reduced to zero, completing a working cycle.

[0041] The working medium containing heat enters the sealed shell 1 and expands adiabatically, driving the male rotor 100 and the female rotor 200 to rotate and do work. While expanding and doing work, the pressure and temperature of the working medium decrease, thereby achieving heat-work conversion. The above three processes of air intake, expansion and exhaust are repeated continuously and work is continuously done externally.

[0042] like Figure 2 As shown, optionally, a front cover 11 is provided at one end of the housing 1, and a rear cover 12 is provided at the other end. One end of the rotating shaft of the male rotor 100 and the female rotor 200 passes through the front cover 11 and is supported by the first bearing box 21, and the other end passes through the rear cover 12 and is supported by the second bearing box 31. The weight and force of the housing 1 are borne by the first bearing box 21 and the second bearing box 31. In this embodiment, two groups of first support bearings 211 and thrust bearings 212 in the first bearing box 21 are provided, one group is installed on the rotating shaft of the male rotor 100, and the other group is installed on the rotating shaft of the female rotor 200. The first support bearing 211 is located on the side of the first bearing box 21 close to the housing 1, and the thrust bearing 212 is located on the side of the first bearing box 21 away from the housing 1. In addition to bearing the gravity of the front ends of the male rotor 100 and the female rotor 200, the first support bearing 211 can also withstand the pressure and disturbance force generated by the steam in the housing 1 on the front ends of the male rotor 100 and the female rotor 200 during the operation of the screw expander. The thrust bearing 212 is used to withstand the thrust generated by steam on the male rotor 100 and the female rotor 200 during the operation of the screw expander, including positive thrust and negative thrust. Similarly, the second support bearing 311 in the second bearing box 31 can withstand the pressure and disturbance force generated by the steam in the casing 1 on the rear ends of the male rotor 100 and the female rotor 200 in addition to the gravity of the rear ends of the male rotor 100 and the female rotor 200 during the operation of the screw expander.

[0043] like Figure 1As shown, optionally, the screw expander also includes a first connecting member 4 and a second connecting member 5, one end of the first connecting member 4 is connected to the first bearing box 21, and the other end is connected to the front cover 11, and one end of the second connecting member 5 is connected to the second bearing box 31, and the other end is connected to the rear cover 12. In this embodiment, preferably, the first connecting member 4 and the second connecting member 5 are both I-shaped plates, and the first connecting member 4 is installed between the first bearing box 21 and the front cover 11 by welding, and the second connecting member 5 is installed between the second bearing box 31 and the rear cover 12 to ensure sufficient connection strength. The weight of the front end of the shell 1 and the force generated by the steam on the shell 1 during the operation of the male rotor 100 and the female rotor 200 can be transmitted to the first bearing box 21 through the first connecting member 4, and then the force is transmitted to the first support 22 through the first bearing box 21. Similarly, the weight of the rear end of the shell 1 and the force exerted by the steam on the shell 1 during the operation of the male rotor 100 and the female rotor 200 can be transmitted to the second bearing box 31 through the second connecting member 5, and then the force is transmitted to the second support 32 through the second bearing box 31.

[0044] like Figure 1 and Figure 2 As shown, optionally, a first oil slinger 23 is provided between the first bearing box 21 and the rotating shaft of the male rotor 100 and between the first bearing box 21 and the rotating shaft of the female rotor 200, and a second oil slinger 33 is provided between the second bearing box 31 and the rotating shaft of the male rotor 100 and between the second bearing box 31 and the rotating shaft of the female rotor 200. By providing the first oil slinger 23 and the second oil slinger 33, the bearing lubricating oil in the first bearing box 21 and the second bearing box 31 can be prevented from leaking to the outside, so as to ensure the normal operation of the first support bearing 211, the second support bearing 311 and the thrust bearing 212.

[0045] Optionally, a first steam seal 24 is provided between the front cover 11 and the rotating shaft of the male rotor 100 and between the front cover 11 and the rotating shaft of the female rotor 200, and a second steam seal 34 is provided between the rear cover 12 and the rotating shaft of the male rotor 100 and between the rear cover 12 and the rotating shaft of the female rotor 200. Since the rotating shafts of the male rotor 100 and the female rotor 200 in this embodiment both pass through the front cover 11 and the rear cover 12 of the housing 1, the first steam seal 24 and the second steam seal 34 can prevent the steam in the housing 1 from leaking through the gap between the rotating shaft and the front cover 11 and the rear cover 12, thereby ensuring that a closed working chamber can be formed inside the housing 1, and the male rotor 100 and the female rotor 200 in the housing 1 can normally perform heat-work conversion.

[0046] Optionally, the screw expander also includes a measuring module, a control module and an alarm module (not shown), the measuring module is used to measure the rotational speed and vibration parameters of the male rotor 100 and the female rotor 200, and send the measurement information to the control module, the control module can receive and process the measurement information, and can send instructions to the alarm module, and the alarm module is used to alarm. In this embodiment, the control module can set the preset value of the rotational speed of the male rotor 100 and the female rotor 200 and the preset value of the vibration parameter. When the rotational speed value and the vibration parameter value measured by the measuring module are greater than the corresponding preset value, the control module can control the alarm module to alarm, so as to prompt the staff to make timely adjustments to ensure that the screw expander can operate safely.

[0047] Optionally, the measuring module includes a speed measuring device 213 and a vibration measuring device. The speed measuring device 213 is disposed in the first bearing box 21 and is used to measure the speed of the rotating shaft of the male rotor 100 and the rotating shaft of the female rotor 200. The vibration measuring device is disposed in the second bearing box 31 and is used to measure the vibration amplitude, frequency and phase of the rotating shaft of the male rotor 100 and the rotating shaft of the female rotor 200. Figure 2 As shown, the shaft ends of the male rotor 100 and the female rotor 200 are both provided with a speed measuring device 213. In this embodiment, preferably, the speed measuring device 213 is a speed sensor, and the vibration measuring device is a vibration measuring instrument, which can measure the vibration amplitude, frequency and phase of the shaft.

[0048] like Figure 2 As shown, optionally, a first synchronous gear 312 and a second synchronous gear 313 meshing with each other are further provided in the second bearing box 31, the first synchronous gear 312 is provided on the rotating shaft of the male rotor 100, and the second synchronous gear 313 is provided on the rotating shaft of the female rotor 200. The first synchronous gear 312 and the second synchronous gear 313 are both located on the side of the second support bearing 311 away from the housing 1, and the first synchronous gear 312 and the second synchronous gear 313 can ensure that the male rotor 100 and the female rotor 200 of the screw expander rotate synchronously.

[0049] like Figure 1As shown, in this embodiment, preferably, the first support 22 is a flexible plate structure, and the second support 32 is a rigid support structure. The flexible plate of the first support 22 can produce flexible deformation, so that the screw expander can expand freely in the axial direction. Reinforcing ribs are provided between the two adjacent support plates of the second support 32, which is a rigid support. This support method can make the screw expander move axially toward the direction of the first support 22 with the second support 32 as the dead point. When the screw expander produces axial displacement due to volume expansion, the flexible plate structure of the first support 22 can absorb the axial displacement of the screw expander and prevent the screw expander from being deflected. In this embodiment, the first support 22 and the second support 32 are both fixed to the ground by bolts. In other embodiments, the first support 22 and the second support 32 can also be fixed on a suitable mounting platform, not necessarily the ground, as long as the screw expander can be installed.

[0050] In this embodiment, optionally, the first bearing box 21 and the second bearing box 31 both include a detachable upper box body and a detachable lower box body. The above arrangement can facilitate the assembly and maintenance of the screw expander and improve the installation efficiency and maintenance efficiency.

[0051] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A screw expander, It is characterized in that include: A housing (1), wherein a male rotor (100) and a female rotor (200) which rotate synchronously are arranged in the housing (1); a first support assembly (2) arranged at intervals on one side of the housing (1), the first support assembly (2) comprising a first bearing box (21) and a first support seat (22), the first support seat (22) being used to support the first bearing box (21), a first support bearing (211) and a thrust bearing (212) being arranged in the first bearing box (21), one end of the rotating shaft of the male rotor (100) and the female rotor (200) being located in the first bearing box (21) and supported by the first support bearing (211) and the thrust bearing (212); a second support assembly (3) arranged at an interval on the other side of the housing (1), the second support assembly (3) comprising a second bearing box (31) and a second support seat (32), the second support seat (32) being used to support the second bearing box (31), a second support bearing (311) being arranged in the second bearing box (31), the other ends of the rotating shafts of the male rotor (100) and the female rotor (200) being both located in the second bearing box (31) and supported by the second support bearing (311); A front cover (11) is provided at one end of the housing (1), and a rear cover (12) is provided at the other end; one end of the rotating shafts of the male rotor (100) and the female rotor (200) passes through the front cover (11) and is supported by the first bearing box (21), and the other end passes through the rear cover (12) and is supported by the second bearing box (31); The first support (22) is a flexible plate structure, and the second support (32) is a rigid support structure.

2. The screw expander according to claim 1, It is characterized in that It also includes a first connecting member (4) and a second connecting member (5), wherein one end of the first connecting member (4) is connected to the first bearing box (21), and the other end is connected to the front cover (11), and one end of the second connecting member (5) is connected to the second bearing box (31), and the other end is connected to the rear cover (12).

3. The screw expander according to claim 1, It is characterized in that A first oil deflector ring (23) is provided between the first bearing box (21) and the rotating shaft of the male rotor (100), and between the first bearing box (21) and the rotating shaft of the female rotor (200), and a second oil deflector ring (33) is provided between the second bearing box (31) and the rotating shaft of the male rotor (100), and between the second bearing box (31) and the rotating shaft of the female rotor (200).

4. The screw expander according to claim 1, It is characterized in that A first steam seal (24) is provided between the front cover (11) and the rotating shaft of the male rotor (100), and between the front cover (11) and the rotating shaft of the female rotor (200), and a second steam seal (34) is provided between the rear cover (12) and the rotating shaft of the male rotor (100), and between the rear cover (12) and the rotating shaft of the female rotor (200).

5. The screw expander according to claim 1, It is characterized in that It also includes a measuring module, a control module and an alarm module. The measuring module is used to measure the rotational speed and vibration parameters of the male rotor (100) and the female rotor (200), and send the measurement information to the control module. The control module can receive and process the measurement information, and can send instructions to the alarm module. The alarm module is used to alarm.

6. The screw expander according to claim 5, It is characterized in that The measuring module comprises a rotation speed measuring device (213) and a vibration measuring device. The rotation speed measuring device (213) is arranged in the first bearing box (21) and is used to measure the rotation speeds of the rotating shaft of the male rotor (100) and the rotating shaft of the female rotor (200). The vibration measuring device is arranged in the second bearing box (31) and is used to measure the vibration amplitude, frequency and phase of the rotating shaft of the male rotor (100) and the rotating shaft of the female rotor (200).

7. The screw expander according to claim 1, It is characterized in that A first synchronous gear (312) and a second synchronous gear (313) meshing with each other are also provided in the second bearing box (31); the first synchronous gear (312) is provided on the rotating shaft of the male rotor (100), and the second synchronous gear (313) is provided on the rotating shaft of the female rotor (200).

8. The screw expander according to any one of claims 1 to 7, It is characterized in that The first bearing box (21) and the second bearing box (31) both comprise a detachable upper box body and a lower box body.

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