A built-in bearing positioning and pre-tightening method for a built-in torque motor

Abstract

The application relates to a built-in bearing positioning and pre-tightening method of a whole set torque motor, which comprises the following steps: fixing a stator shell with a flange end downward; pressing a bearing into the bottom end of a bearing installation hole on the stator shell, so that the outer ring end face of the bearing is in contact with a stop face in the stator shell; pushing bearing inner and outer ring gaskets into the bearing installation hole of the stator shell from top to bottom, and respectively contacting the outer ring end face and the inner ring end face of the installed bearing; pushing another bearing into the bearing installation hole of the stator shell, so that the inner and outer rings are respectively in contact with the upper end face of the bearing inner ring gasket and the upper end face of the bearing outer ring gasket; rotating a stator locking nut on a mounting screw port on the stator shell, and pressing the outer ring of the installed bearing; rotating a rotor shaft through the stator assembly, and making the root part of the rotor shaft in contact with the inner ring end face of the installed bearing; rotating a rotor locking nut on the outer threaded installation section on the rotor shaft, and pressing the inner ring end face of the installed bearing, so that the pre-tightening of the bearing is completed.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of motor installation, and particularly relates to a built-in bearing positioning and pre-tightening method for an integrated torque motor. BACKGROUND

[0002] As an important executive component in a dynamic system, a motor is widely used in various transmission systems. According to the application environment of different systems, the installation mode of the motor on the system is also different.

[0003] For a general integrated permanent magnet motor, the rotor and the motor shaft are an integral structure, and the stator and the rotor are connected through two bearings. As a core component determining the service life, noise and friction torque of the motor, the bearing mainly functions to support the rotating body, reduce the friction coefficient in the movement process thereof, and ensure the rotation accuracy thereof. For an external bearing positioning and pre-tightening method, it is relatively mature. However, for a built-in bearing, currently, three methods are generally used for bearing pre-tightening: 1. A wave-shaped gasket is used to fix the bearing at one end; 2. An elastic retainer is used to fix the bearing at one end; and 3. Two lock nuts are used to lock the entire shaft system at one of the bearings (usually the outer bearing). The first two methods belong to fixed-pressure pre-tightening, and are suitable for high-speed low-load and low-environment adaptability. The third method, although belonging to positioning and pre-tightening, has higher rigidity and better anti-impact and anti-vibration characteristics, but it is difficult to accurately quantify the pre-tightening force of a single bearing by using the double lock nuts, and only the force of the two lock nuts can be quantified, and the far end does not directly contact the lock nut, and is affected by the entire shaft system, so it is difficult to ensure that the pre-tightening force is applied in place. Thus, the shaft system rigidity and anti-impact capacity are reduced. In summary, there is currently no simple and reliable built-in bearing positioning and pre-tightening method for an integrated torque motor.

[0004] SUMMARY

[0005] The application proposes a built-in bearing positioning and pre-tightening method for an integrated torque motor, which has high strength, good reliability, and can meet the use requirements of high-level impact and vibration environment.

[0006] The above object of the application is achieved by the following technical scheme.

[0007] A built-in bearing positioning and pre-tightening method for an integrated torque motor, the integrated torque motor involved in the method comprises a stator shell, a rotor shaft, a rotor locking nut, a bearing, a bearing inner ring pad sleeve, a bearing outer ring pad sleeve and a stator locking nut.

[0008] The stator shell is a flange type hollow structure, the inner hole thereof is a bearing mounting hole, and a mounting screw hole is arranged at one end of the inner hole away from the flange.

[0009] The rotor shaft adopts a flange type hollow mechanism, and an externally threaded mounting section is arranged at one end away from the flange thereof;

[0010] The stator locking nut adopts a nut structure provided with a central hole and externally threaded on the outer circumferential surface;

[0011] The inner circumferential surface of the rotor locking nut is provided with threads;

[0012] The method for positioning and pre-tightening the bearing based on the built-in torque motor is as follows:

[0013] Step 1, fix the stator shell with the flange end at the lower part;

[0014] Step 2, use a tool to press one bearing into the bottom end of the bearing mounting hole on the stator shell, so that the outer ring end surface of the bearing is in complete contact with the stop surface in the stator shell;

[0015] Step 3, push the bearing outer ring gasket into the bearing mounting hole of the stator shell from top to bottom until it is in contact with the end surface of the bearing outer ring; and push the bearing inner ring gasket into the bearing mounting hole of the stator shell from top to bottom until the end surface thereof is in contact with the end surface of the assembled bearing inner ring;

[0016] Step 4, push another bearing into the bearing mounting hole of the stator shell from top to bottom, so that the inner and outer rings thereof are in contact with the upper end surface of the bearing inner ring gasket and the upper end surface of the bearing outer ring gasket, respectively;

[0017] Step 5, screw the stator locking nut into the mounting screw hole on the stator shell, and press the outer ring of the bearing installed in step 4 to form an integrated stator assembly;

[0018] Step 6, use a guide tool to cooperate with the hollow hole of the rotor shaft, and make the rotor shaft pass through the assembled stator assembly from the end away from the flange of the stator shell, so that the outer surface of the rotor shaft is in cooperation with the bearing and the inner hole surface of the bearing inner ring gasket, and the rotor shaft root boss is in contact with the end surface of the bearing inner ring;

[0019] Step 7, screw the rotor locking nut onto the externally threaded mounting section on the rotor shaft, and press the inner ring end surface of the bearing installed in step 2 to complete the pre-tightening of the bearing.

[0020] Moreover, in step 5, a torque wrench is used to screw the stator locking nut.

[0021] Moreover, in step 7, a torque wrench is used to screw the rotor locking nut.

[0022] Moreover, four blind holes are arranged on the outer ends of the rotor locking nut and the stator locking nut in the circumferential direction, which are wrench insertion holes.

[0023] The application has the advantages and positive effects that:

[0024] 1、The application realizes the double-end positioning and pre-tightening of the two bearings by the outer ring of one end bearing being pressed by the stator locking nut, the inner ring of the other end bearing being pressed by the rotor locking nut, the stop surface in the stator shell, the shaft root boss of the rotor, the bearing inner ring gasket and the bearing outer ring heat ring, the pressing mode makes the two end faces of the bearing inner and outer rings effectively supported, has the advantages of high strength and good stability, and can work normally in a large load and high level impact environment.

[0025] 2、When the nut is locked, the torque wrench can be used to quantify the pre-tightening force of the two bearings, effectively quantitatively control the bearing play, and greatly improve the reliability and stiffness of the motor shaft system.

[0026] 3、The shaft system is supported in the shell, can share the axial space of the motor winding and permanent magnet, does not occupy additional axial space, and reduces the axial size of the motor to a certain extent. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is the overall structure diagram of the integral type torque motor involved in the application.

[0028] Figure 2 It is the three-dimensional explosion diagram of the integral type torque motor involved in the application.

[0029] Figure 3 It is the structure diagram of the stator shell involved in the application, 3a, three-dimensional appearance diagram; 3b, longitudinal section view.

[0030] Figure 4 It is the structure diagram of the rotor shaft involved in the application, 4a, longitudinal section view, 4b, three-dimensional view.

[0031] Figure 5 It is the structure diagram of the stator locking nut involved in the application, 5a, three-dimensional Figure 1 ; 5b, three-dimensional Figure 2 ;

[0032] Figure 6 It is the structure diagram of the rotor locking nut involved in the application, 6a, three-dimensional Figure 1 ; 6b, three-dimensional Figure 2 ; DETAILED DESCRIPTION

[0033] The structure of the application will be further described below in combination with the drawings and through examples. It should be noted that the examples are narrative rather than limiting.

[0034] A built-in bearing positioning and pre-tightening method of an integral type torque motor, please refer toFigures 1-6 The method relates to a whole-set torque motor, which comprises a stator shell 1, a rotor shaft 2, a rotor locking nut 3, bearings 4, bearing inner ring gaskets 5, bearing outer ring gaskets 6 and a stator locking nut 7.

[0035] The stator shell is a flange type hollow structure, the inner hole of the stator shell is a bearing mounting hole, the bearing mounting hole is matched with two bearing outer rings to play a guiding role, meanwhile, a mounting screw hole 1.2 of the stator locking nut is arranged at one end of the inner hole of the stator shell away from the flange, so that the outer ring end surface of the bearing is positioned. The outer surface of the stator shell is used for mounting and fixing the core winding;

[0036] The rotor shaft is also a flange type hollow structure, the rotor shaft plays a guiding role on the two bearing inner rings, meanwhile, an outer threaded mounting section 2.1 for mounting the rotor locking nut is arranged at one end away from the flange and located on the outside of the bearing, so that the inner ring end surface of the bearing is positioned.

[0037] The stator locking nut adopts a nut structure provided with a central hole and an outer thread 7.1 arranged on the outer circumferential surface, the stator locking nut is used for being fixedly connected with the stator shell and positioning and pressing the bearing outer ring.

[0038] The inner circumferential surface of the rotor locking nut is provided with a thread 3.1, the rotor locking nut is used for being fixed with the rotor shaft and positioning and pressing the bearing inner ring.

[0039] The bearing inner ring gasket is arranged between the two bearings and is used for supporting the inner ring between the two bearings.

[0040] The bearing outer ring gasket is arranged between the two bearings and is used for supporting the outer ring between the two bearings.

[0041] The method for positioning and pre-tightening the bearings of the whole-set torque motor is as follows:

[0042] Step 1, the stator shell is fixed in a manner that the flange end is located at the lower part;

[0043] Step 2, a bearing is pressed into the bottom end of the bearing mounting hole on the stator shell by using a tool, so that the outer ring end surface of the bearing is in complete contact with the stop surface 1.1 in the stator shell;

[0044] Step 3, the bearing outer ring gasket is pushed into the bearing mounting hole of the stator shell from top to bottom until the bearing outer ring end surface is in contact with the bearing outer ring gasket, and the bearing inner ring gasket is pushed into the bearing mounting hole of the stator shell from top to bottom until the end surface is in contact with the bearing inner ring;

[0045] Step 4, another bearing is pushed into the bearing mounting hole of the stator shell from top to bottom, so that the inner ring and the outer ring are respectively in contact with the upper end surface of the bearing inner ring gasket and the upper end surface of the bearing outer ring gasket.

[0046] Step 5, screw the stator lock nut on the mounting screw of the stator housing, and press the outer ring of the bearing installed in step 4. Form an integrated stator assembly.

[0047] Step 6, use a guide tool to cooperate with the hollow hole of the rotor shaft, pass the rotor shaft through the assembled stator assembly from the end away from the flange of the stator housing, and ensure that the final rotor shaft root boss 2.2 is in close contact with the end face of the bearing inner ring.

[0048] Step 7, screw the rotor lock nut onto the outer threaded mounting section of the rotor shaft, and press the inner ring end face of the bearing installed in step 2. At this time, the built-in bearing positioning and pre-tightening operation is completed. The upper and lower end faces of the inner and outer rings of the two built-in bearings are fully supported.

[0049] In order to achieve the installation of the stator lock nut and the rotor lock nut, four blind holes are arranged on the outer end of the rotor lock nut and the stator lock nut in the circumferential direction.

[0050] In order to quantify the pre-tightening force of the two bearings, torque wrenches are used when installing the stator lock nut and the rotor lock nut in the present application.

[0051] In the above technical solution, as a preferred solution, thin gaskets can be added to the end faces of the bearing inner and outer rings and the pressing member to adjust the relative position of the bearing inner and outer rings in the axial direction, thereby adjusting the play of the pre-tightened bearing. Thin gaskets made of stainless steel 06Cr19Ni10 or brass H62 material can be used.

[0052] In the above technical solution, as a preferred solution, the hollow axial dimension of the stator housing is designed to be as small as possible to shorten the distance between the two bearings and improve reliability.

[0053] In the above technical solution, as a preferred solution, a threaded interface for motor axial movement test is reserved on the rear end face of the rotor shaft to determine whether the positioning and pre-tightening is in place, and the threaded interface is designed in a hollow form to serve as a guide during the installation of the entire machine.

[0054] In the above technical solution, as a preferred solution, the rotor lock nut and the stator lock nut can be made of titanium alloy TC4.M material with high mechanical strength and low density to reduce the overall weight while ensuring locking strength.

[0055] Although the embodiments and drawings of the present application are disclosed for illustrative purposes, those skilled in the art can understand that various alternatives, changes and modifications are possible without departing from the spirit and scope of the present application and the appended claims, therefore, the scope of the present application is not limited to the disclosed content of the embodiments and drawings.

Claims

1. A method for positioning and pre-tightening an integrated bearing in a fully assembled torque motor, characterized in that: The method involves an integrated torque motor including a stator housing, a rotor shaft, a rotor lock nut, a bearing, an inner bearing ring washer, an outer bearing ring washer, and a stator lock nut; The stator housing is a flange-type hollow structure, and its inner hole is a bearing mounting hole. A mounting thread is provided at the end of the inner hole away from the flange. The rotor shaft adopts a flange-type hollow mechanism, with an external threaded mounting section provided at the end away from the flange. The stator locking nut adopts a nut structure with a central hole and external threads on the outer circumferential surface; The inner circumferential surface of the rotor locking nut is threaded; The method for positioning and pre-tightening the bearings based on this integrated torque motor is as follows: Step 1: Secure the stator housing with the flange end at the bottom; Step 2: Use a tool to press a bearing into the bottom of the bearing mounting hole on the stator housing, so that the outer ring end face of the bearing is in complete contact with the stop surface inside the stator housing; Step 3: Push the outer ring washer into the bearing mounting hole of the stator housing from top to bottom until it contacts the end face of the installed outer ring of the bearing; and push the inner ring washer into the bearing mounting hole of the stator housing from top to bottom until its end face fits against the end face of the assembled inner ring of the bearing. Step 4: Push the other bearing into the bearing mounting hole of the stator housing from top to bottom, so that its inner and outer rings are respectively in contact with the upper end face of the assembled bearing inner ring washer and the upper end face of the bearing outer ring washer. Step 5: Screw the stator lock nut into the mounting screw hole on the stator housing to tighten the outer ring of the bearing installed in Step 4, forming an integrated stator assembly; Step 6: Using a guide tool to fit the hollow hole of the rotor shaft, the rotor shaft passes through the assembled stator assembly from the flange end away from the stator housing. The outer surface of the rotor shaft fits with the bearing and the inner hole surface of the bearing inner ring gasket, and the boss at the root of the rotor shaft fits against the end face of the inner ring of the bearing that is installed later. Step 7: Screw the rotor lock nut onto the external thread mounting section on the rotor shaft to press the inner ring end face of the bearing installed in Step 2, thus completing the pre-tightening of the bearing.

2. The method for positioning and pre-tightening the built-in bearing of the integrated torque motor according to claim 1, characterized in that: In step 5, use a torque wrench to tighten the stator lock nut.

3. The method for positioning and pre-tightening the built-in bearing of an integrated torque motor according to claim 1 or 2, characterized in that: In step 7, use a torque wrench to tighten the rotor lock nut.

4. The method for positioning and pre-tightening the built-in bearing of the integrated torque motor according to claim 1, characterized in that: Four blind holes are evenly distributed along the circumference at the outer ends of both the rotor locking nut and the stator locking nut, serving as wrench insertion holes.

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