A dual-sensor switched reluctance motor

Abstract

The utility model relates to a kind of dual-sensor switched reluctance motor, belong to switched reluctance motor technical field.It includes casing (1) and motor shaft (20), multiple sensor cavities for arranging sensor are provided in one end of casing (1), motor shaft (20) is introduced into sensor cavity after leading out from casing (1) end, and it is connected with sensor in sensor cavity, it is characterized by: sensor cavity includes first sensor cavity and second sensor cavity, motor shaft (20) enters first sensor cavity, and it is connected with first sensor in it, second sensor and the second rotating shaft for driving second sensor rotation are arranged in second sensor cavity, second rotating shaft is coaxially fixed with motor shaft (20), and axially sliding connection.In the dual-sensor switched reluctance motor of the application, the rotating shaft of first sensor and second sensor is coaxially fixed and axially sliding connection, effectively avoid the problem that sensor fails even damages due to motor shaft occurs and shifts.

Description

Technical Field

[0001] A dual-sensor switched reluctance motor belongs to the field of switched reluctance motor technology. Background Technology

[0002] Switched reluctance motors (SRMs) are widely used in various industries due to their simple structure, reliable performance, low starting current, high starting torque, wide speed range, and high efficiency. During operation, SRMs require sensors (such as Hall effect sensors or rotary transformers) at their rear end cover to confirm the rotor position. However, due to their relatively low protection level and susceptibility to aging, these sensors are prone to failure or accuracy degradation, which can lead to current imbalances in different phases during motor control and damage to the controller's power devices.

[0003] In existing technologies, one solution to problems such as current imbalance caused by sensor issues and damage to controller power devices in switched reluctance motors is to use redundant sensors in the switched reluctance motor, i.e., to set up multiple sensors in the switched reluctance motor. Examples of such solutions include: the technical solution described in Chinese invention patent application number 201910090996.2, filed January 30, 2019, entitled "Switched Reluctance Motor Sensor Redundancy System and Automatic Switching Method"; the technical solution described in Chinese invention patent application number 201910351590.5, filed April 28, 2019, entitled "A Switched Reluctance Motor with Multi-Sensor Operation"; and the technical solution described in Chinese utility model patent application number 201820257693.6, filed February 13, 2018, entitled "A Motor Speed ​​Acquisition System Based on Redundant Sensors".

[0004] However, switched reluctance motors with sensor redundancy designs, including the aforementioned technical solutions, have the following drawbacks in practical implementation: The multiple redundant sensors in a switched reluctance motor all need to rotate synchronously with the motor shaft. However, in applications with significant vibration, such as forging, the motor shaft is prone to axial movement. For sensors, whether Hall effect sensors or rotary transformers, they consist of two relatively rotating parts (such as the rotor and stator of a rotary transformer). This means that large axial movement of the motor shaft can easily lead to decreased sensor measurement accuracy or even failure. Secondly, when the motor shaft experiences axial movement, it also applies axial tension (or thrust) to the sensor, which can easily damage the sensor. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a dual-sensor switched reluctance motor in which the rotating shafts of the first sensor and the second sensor are coaxially fixed and axially slidingly connected, effectively avoiding sensor failure or even damage due to the movement of the motor shaft.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows: The dual-sensor switched reluctance motor includes a housing, a motor shaft is rotatably arranged inside the housing, and a plurality of sensor cavities for arranging sensors are arranged at one end of the housing. The motor shaft is led out from the end of the housing and enters the sensor cavity and is connected to the sensor in the sensor cavity. The sensor cavity includes a first sensor cavity and a second sensor cavity. The motor shaft enters the first sensor cavity and is connected to the first sensor inside it. The second sensor cavity is provided with a second sensor and a second rotating shaft that drives the second sensor to rotate. The second rotating shaft is coaxially fixed with the motor shaft and is axially slidably connected.

[0007] Preferably, the second rotating shaft is a splined shaft disposed in the second sensor cavity, and the splined shaft is connected to the motor shaft in the first sensor cavity via a spline.

[0008] Preferably, the sensor cover is fixed to the end of the housing to form a first sensor cavity, and the motor shaft enters the first sensor cavity; the first sensor is a Hall sensor set on the inner wall of the sensor cover, and a gear plate that rotates relative to the Hall sensor and is used to trigger the Hall sensor is mounted on the motor shaft.

[0009] Preferably, a number of disk teeth are evenly arranged on the outer periphery of the end face of the toothed disk facing the Hall sensor, and the Hall sensor is located on the rotation path of the disk teeth.

[0010] Preferably, a motor shaft positioning table is provided on the surface of the motor shaft, the gear plate is clamped at the motor shaft positioning table, and an inner spline bushing for fixing the gear plate is fixed at the end of the motor shaft.

[0011] Preferably, the height of the disc teeth is 13mm to 18mm.

[0012] Preferably, a front bearing housing is fixed at the outer end face of the first sensor, and a rear bearing housing is fixed at the outer end of the front bearing housing to form a second sensor cavity. The second sensor is a rotary transformer disposed in the second sensor cavity.

[0013] Preferably, a front bearing and a rear bearing are respectively provided at the center of the front bearing housing and the rear bearing housing, and the splined shaft passes through the front bearing and the rear bearing.

[0014] Preferably, a splined shaft positioning stage is provided on the surface of the splined shaft, the rotor of the rotary transformer is locked at the splined shaft positioning stage, and the stator of the rotary transformer is fixed inside the second sensor cavity.

[0015] Compared with the prior art, the beneficial effects of this utility model are: In the dual-sensor switched reluctance motor of this application, the rotating shafts of the first sensor and the second sensor are coaxially fixed and axially slidingly connected, which ensures that when the motor shaft moves axially, the spline shaft and the inner spline bushing can be reliably connected, and no axial tension is applied to the spline shaft, effectively avoiding the problem of sensor failure or even damage due to the movement of the motor shaft.

[0016] A front bearing is arranged in the center hole at the rear end of the front bearing housing, and a rear bearing is arranged in the center hole at the front end of the rear bearing housing. The front and rear bearings work together to support the splined shaft.

[0017] In the prior art, the height of the disc teeth is approximately 10mm. In this application, the height of the disc teeth is increased to 13mm~18mm. By increasing the length of the disc teeth, the axial movement of the motor shaft in certain situations can be offset, ensuring that the disc teeth can reliably engage with the Hall sensor.

[0018] In the applied switched reluctance motor, the rotor of the rotary transformer is positioned and fixed by a splined shaft positioning table and a pressure cover. By determining the opening position of the splined shaft positioning table, the installation position of the rotary transformer rotor can be accurately positioned. Simultaneously, the gear disc is positioned and fixed by a motor shaft positioning table and an inner splined bushing. By determining the opening position of the motor shaft positioning table, the installation position of the gear disc can be accurately positioned. Attached Figure Description

[0019] Figure 1 This is a partial cross-sectional view of a dual-sensor switched reluctance motor.

[0020] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0021] The components include: 1. Housing; 2. Rear end cover; 3. Outer shaft cover; 4. Sensor cover; 5. Gear disc; 6. Disc teeth; 7. Motor shaft positioning table; 8. Inner spline bushing; 9. Front bearing seat; 10. Front bearing; 11. Rear bearing seat; 12. Pressure cover; 13. Spline shaft; 14. Rear bearing; 15. Spline shaft positioning table; 16. Rotary transformer rotor; 17. Rotary transformer stator; 18. Rotary transformer fixing seat; 19. Hall sensor; 20. Motor shaft. Detailed Implementation

[0022] Figures 1-2 This is the preferred embodiment of the present invention, which is described below in conjunction with the appendix. Figures 1-2 The present invention will be further described below.

[0023] like Figures 1-2 As shown, a dual-sensor switched reluctance motor (hereinafter referred to as the switched reluctance motor) includes a housing 1, and a rear end cover 2 is fixed at the rear port of the housing 1. A motor shaft 20 is rotatably disposed inside the housing 1, and the motor shaft 20 extends out from the center hole of the rear end cover 2.

[0024] An outer shaft cover 3 is coaxially fixed at the center of the outer end face of the rear end cover 2. A sensor cover 4 is also fixed on the outer end face of the outer shaft cover 3. The sensor cover 4 and the outer shaft cover 3 are spaced apart to form a first sensor cavity. The motor shaft 20 passes through the center of the outer shaft cover 3 and enters the first sensor cavity.

[0025] A motor shaft positioning platform 7 is provided on the surface of the motor shaft 20, located inside the first sensor cavity. A gear disk 5 is fitted onto the outside of the motor shaft 20, with its inner end engaged with the motor shaft positioning platform 7. An inner spline bushing 8 is coaxially fixed to the end of the motor shaft 20 by multiple bolts. The inner end of the inner spline bushing 8 fits against the outer end of the gear disk 5, thus clamping and fixing the gear disk 5. Therefore, in the switched reluctance motor of this application, the positioning and fixing of the gear disk 5 are achieved jointly by the motor shaft positioning platform 7 and the inner spline bushing 8. By determining the location of the motor shaft positioning platform 7, the precise positioning of the gear disk 5 can be achieved.

[0026] A Hall sensor 19 is fixed on the inner end face of the sensor cover 4. Similar to the prior art, several teeth 6 are vertically arranged on the outer ring of the toothed disk 5 facing the sensor cover 4. The teeth 6 pass through the Hall sensor 19. When the toothed disk 5 rotates with the motor shaft 20, it continuously rotates relative to the Hall sensor 19 through the teeth 6, thereby realizing the detection of the position of the motor shaft 20 (motor rotor).

[0027] In the prior art, the height of the tooth 6 protruding from the surface of the tooth disk 5 is about 10mm. In the switched reluctance motor of this application, the height of the tooth 6 is increased to 13mm~18mm, preferably 15mm. By increasing the length of the tooth 6, the axial movement of the motor shaft 20 in certain situations can be offset, so as to ensure that the tooth 6 can reliably cooperate with the Hall sensor 19.

[0028] A front bearing housing 9 is fixed to the rear end face of the sensor cover 4 by multiple bolts around the perimeter. A resolver fixing seat 18 is fixed to the rear end face of the front bearing housing 9 by multiple bolts around the perimeter. A rear bearing housing 11 is fixed to the rear end face of the resolver fixing seat 18 by multiple bolts around the perimeter. The front bearing housing 9, the resolver fixing seat 18, and the rear bearing housing 11 together form the second sensor cavity of this switched reluctance motor.

[0029] A splined shaft 13 is rotatably mounted inside the second sensor cavity. The front end of the splined shaft 13 passes forward through the front bearing housing 9 and the sensor cover 4 before entering the first sensor cavity. Within the first sensor cavity, it passes through the center of the inner splined sleeve 8, and the splined shaft 13 and the inner splined sleeve 8 are slidably connected via splines. This splined sliding connection ensures that the inner splined sleeve 8 and the splined shaft 13 can rotate synchronously, while allowing for a certain axial sliding distance between them. This ensures a reliable connection between the splined shaft 13 and the inner splined sleeve 8 even if the motor shaft 20 experiences axial movement, without applying axial tension to the splined shaft 13.

[0030] A front bearing 10 is arranged in the center hole at the rear end of the front bearing housing 9, and a rear bearing 14 is arranged in the center hole at the front end of the rear bearing housing 11. The spline shaft 13 passes through the inner rings of both the front bearing 10 and the rear bearing 14, and the front bearing 10 and the rear bearing 14 work together to support the spline shaft 13.

[0031] The sensor arranged in the second sensor cavity is a rotary transformer, which includes a rotary transformer rotor 16 and a rotary transformer stator 17. The rotary transformer stator 17 is fixed to the surface of the rotary transformer mounting base 18. A splined shaft positioning platform 15 is formed on the surface of the splined shaft 13. The rotary transformer rotor 16 is fitted onto the outer ring of the splined shaft 13, and the inner end of the rotary transformer rotor 16 abuts against the splined shaft positioning platform 15. A pressure cap 12 is also provided on the outside of the rotary transformer rotor 16. The pressure cap 12 is fitted onto the outer ring of the splined shaft 13 and is coaxially fixed to the splined shaft 13 by multiple bolts around its periphery.

[0032] After the pressure cap 12 is fixed to the spline shaft 13, its inner end abuts against the outer end of the rotary transformer rotor 16. Therefore, in the switched reluctance motor of this application, the positioning and fixing of the rotary transformer rotor 16 are achieved by the spline shaft positioning table 15 and the pressure cap 12. By determining the opening position of the spline shaft positioning table 15, the precise positioning of the installation position of the rotary transformer rotor 16 can be achieved.

[0033] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from its technical solution shall still fall within the protection scope of this utility model.

Claims

1. A dual-sensor switched reluctance motor, comprising a housing (1), a motor shaft (20) rotatably disposed within the housing (1), and a plurality of sensor cavities for arranging sensors disposed at one end of the housing (1), wherein the motor shaft (20) extends from the end of the housing (1) and enters the sensor cavity, and is connected to the sensors in the sensor cavity, characterized in that: The sensor cavity includes a first sensor cavity and a second sensor cavity. The motor shaft (20) enters the first sensor cavity and is connected to the first sensor inside it. The second sensor cavity is provided with a second sensor and a second rotating shaft that drives the second sensor to rotate. The second rotating shaft is coaxially fixed with the motor shaft (20) and is axially slidably connected. The second rotating shaft is a splined shaft (13) located in the second sensor cavity. The splined shaft (13) is connected to the motor shaft (20) in the first sensor cavity via a spline. A spline shaft positioning stage (15) is provided on the surface of the spline shaft (13). The rotary transformer rotor (16) of the rotary transformer is locked at the spline shaft positioning stage (15), and the rotary transformer stator (17) is fixed in the second sensor cavity.

2. The dual-sensor switched reluctance motor according to claim 1, characterized in that: The sensor cover (4) is fixed to the end of the housing (1) to form the first sensor cavity, and the motor shaft (20) enters the first sensor cavity; the first sensor is a Hall sensor (19) set on the inner wall of the sensor cover (4), and a gear disk (5) is mounted on the motor shaft (20) that rotates relative to the Hall sensor (19) and is used to trigger the Hall sensor (19).

3. The dual-sensor switched reluctance motor according to claim 2, characterized in that: On the outer periphery of the toothed disk (5) facing the end face of the Hall sensor (19), there are several disk teeth (6) evenly arranged, and the Hall sensor (19) is located on the rotation path of the disk teeth (6).

4. The dual-sensor switched reluctance motor according to claim 2, characterized in that: A motor shaft positioning table (7) is provided on the surface of the motor shaft (20), and the gear plate (5) is clamped at the motor shaft positioning table (7). An inner spline bushing (8) for fixing the gear plate (5) is fixed at the end of the motor shaft (20).

5. The dual-sensor switched reluctance motor according to claim 3, characterized in that: The height of the disc teeth (6) is 13mm~18mm.

6. The dual-sensor switched reluctance motor according to claim 1, characterized in that: A front bearing housing (9) is fixed at the outer end face of the first sensor, and a rear bearing housing (11) is fixed at the outer end of the front bearing housing (9) to form a second sensor cavity. The second sensor is a rotary transformer set in the second sensor cavity.

7. The dual-sensor switched reluctance motor according to claim 6, characterized in that: A front bearing (10) and a rear bearing (14) are respectively provided at the center of the front bearing housing (9) and the rear bearing housing (11), and a splined shaft (13) passes through the front bearing (10) and the rear bearing (14).

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