Motor rotor assembly

Abstract

The utility model discloses a motor rotor assembly which comprises an impeller, a first bearing, a second bearing, a first spring, a second spring and a blocking piece. The impeller is connected to one end of the rotating shaft, the first bearing and the second bearing are fixedly sleeved to the rotating shaft through the inner rings, and the first bearing is located between the impeller and the second bearing; the rotating shaft is sleeved with the first spring, and one end of the first spring abuts against the first bearing; the rotating shaft is sleeved with the second spring, and one end of the second spring abuts against the second bearing; the blocking piece is fixed to the rotating shaft, and the end, away from the first bearing, of the first spring and the end, away from the second bearing, of the second spring abut against the blocking piece; a first elastic force applied to the first bearing by the first spring and a second elastic force applied to the second bearing by the second spring are mutually independently arranged, and the first elastic force and the second elastic force are respectively used for independently superposing or counteracting reverse thrust generated by rotation of the impeller, so that the actual pre-tightening force of the first bearing and the actual pre-tightening force of the second bearing are both within a preset pre-tightening force range.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, and in particular to a motor rotor assembly. Background Art

[0002] Traditional motor rotor assemblies usually have a preload spring between two bearings, which provides the same initial preload force to the two bearings. However, in high-speed motors, the rotation of the impeller generates airflow when the high-speed motor is running, thereby generating a reverse thrust acting on the motor itself. When the reverse thrust acts on the rotor assembly of the motor, it changes the initial preload force applied by the spring to the two bearings, causing the actual preload force of the spring on the two bearings to be different, and both actual preload forces deviate from the preset preload force range. If the preload force of the bearing is too small, it will cause motor noise, and if the preload force of the bearing is too large, it will cause the bearing to be subjected to large force, friction and heat, affecting the bearing life. Specifically, the outer ring of the bearing is in contact with the spring, the inner ring of the bearing is fixed to the rotating shaft, and the impeller is also fixed to the rotating shaft. The spring between the two bearings pushes the two outer rings of the bearings in opposite directions, so that the bearings obtain an initial preload. When the motor is working, the impeller rotates to generate a reverse thrust, which is applied to the inner ring of the bearing through the rotating shaft. At this time, the initial preload and the reverse thrust are superimposed or partially offset each other to generate the actual preload of the bearing, so that the preload of the bearing on one side is reduced and the preload of the bearing on the other side is increased.

[0003] Therefore, there is an urgent need for a new motor rotor assembly, in which when the motor runs at high speed, the preload forces borne by the two bearings are within a preset preload force range, so as to reduce noise generation and increase the life of the bearings. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a motor rotor assembly to solve the problem that the reverse thrust generated when the motor is running causes the preload forces on the two bearings to be too large or too small, and the preload forces are not within the originally designed range, thereby generating noise and affecting the life of the bearings.

[0005] The above technical objectives of the utility model are achieved through the following technical solutions:

[0006] A motor rotor assembly comprises a rotating shaft, an impeller, a first bearing, a second bearing, a first spring, a second spring and a blocking member; the impeller is connected to one end of the rotating shaft, the first bearing and the second bearing are both fixed to the rotating shaft by inner ring sleeve, and the first bearing is located between the impeller and the second bearing; the first spring is sleeved on the rotating shaft, and one end of the first spring abuts against the first bearing; the second spring is sleeved on the rotating shaft, and one end of the second spring abuts against the second bearing; at least one blocking member is fixed to the rotating shaft, and one end of the first spring away from the first bearing and one end of the second spring away from the second bearing respectively abut against the blocking member; a first elastic force applied by the first spring to the first bearing and a second elastic force applied by the second spring to the second bearing are independently arranged, and the first elastic force and the second elastic force are respectively used to separately superimpose or offset the reverse thrust generated by the rotation of the impeller, so that the actual preload force of the first bearing and the actual preload force of the second bearing are both within the preset preload force range.

[0007] Further, the first spring and the second spring are located between the first bearing and the second bearing, and the blocking member is located between the first spring and the second spring; wherein the first elastic force is greater than the second elastic force.

[0008] Furthermore, the at least one blocking member includes a first blocking member and a second blocking member, wherein the first blocking member is located on a side of the first spring away from the first bearing for the first spring to abut against, and the second blocking member is located on a side of the second spring away from the second bearing for the second spring to abut against.

[0009] Furthermore, the first spring and the first blocking member are located between the first bearing and the impeller, and the second spring and the second blocking member are located on a side of the second bearing away from the first bearing; wherein the first elastic force is smaller than the second elastic force.

[0010] Further, the first spring and the first blocking member are located between the first bearing and the impeller, and the second spring and the second blocking member are located between the first bearing and the second bearing; wherein the first elastic force and the second elastic force are equal.

[0011] Furthermore, the first spring and the first blocking member are located between the first bearing and the second bearing, and the second spring and the second blocking member are located on a side of the second bearing away from the first bearing; wherein the first elastic force and the second elastic force are equal.

[0012] Furthermore, the difference between the first elastic force and the second elastic force ranges from 1N to 4N.

[0013] Furthermore, the ends of the first spring and the second spring each have a cutting plane, and the first spring abuts against the first bearing and the blocking member respectively through the cutting plane; the second spring abuts against the second bearing and the blocking member respectively through the cutting plane.

[0014] Further, the outer diameter of the first spring is smaller than the outer diameter of the outer ring of the first bearing, and the inner diameter of the first spring is larger than the inner diameter of the outer ring of the first bearing, so that the first spring abuts against the outer ring of the first bearing;

[0015] The outer diameter of the second spring is smaller than the outer diameter of the second bearing outer ring, and the inner diameter of the second spring is larger than the inner diameter of the second bearing outer ring, so that the second spring abuts against the outer ring of the second bearing.

[0016] Further, the elastic coefficients of the first spring and the second spring are consistent, and the compression amount of the first spring is greater than the compression amount of the second spring; or, the compression amounts of the first spring and the second spring are the same, and the elastic coefficient of the first spring is greater than the elastic coefficient of the second spring.

[0017] The beneficial effects of the embodiments of the utility model are:

[0018] The present application sets two springs to set the initial preload for the two bearings respectively. The first spring applies a first elastic force to the first bearing, and the second spring applies a second elastic force to the second bearing. The first bearing and the second bearing are respectively provided with elastic force, i.e., initial preload, by separate springs, and will not affect each other. Moreover, the first elastic force and the second elastic force can be set separately through the setting of the blocking member, so that the first bearing and the second bearing respectively obtain initial preload of appropriate size, so that the first elastic force and the second elastic force can be used to separately superimpose or offset the reverse thrust generated by the impeller, so that the actual preload of the first bearing and the actual preload of the second bearing are both within the preset preload range, avoiding the problem of the actual preload of the first bearing and the second bearing being too large or too small, thereby reducing noise and improving the service life of the bearings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the embodiments of the present application, the drawings required for use in the embodiments of the present application are briefly introduced below.

[0020] Figure 1 This is an overall schematic diagram of a motor rotor assembly according to an embodiment of the present application;

[0021] Figure 2 This is a schematic structural diagram of a first spring, a second spring and a blocking member arranged between a first bearing and a second bearing according to an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the structure of a first spring and a first blocking member, a second spring and a second blocking member according to an embodiment of the present application;

[0023] Figure 4 A schematic diagram of the structure of a first spring and a first blocking member, a second spring and a second blocking member shown in another embodiment of the present application;

[0024] Figure 5 A schematic diagram of the structure of the first spring and the first blocking member, the second spring and the second blocking member shown in other embodiments of the present application;

[0025] Figure 6 This is a schematic diagram of the structure of a first spring shown in an embodiment of the present application;

[0026] Figure 7 This is a schematic diagram of the structure of a second spring shown in an embodiment of the present application;

[0027] Figure 8 A side view of a first spring shown in one embodiment of the present application;

[0028] Fig. 9 A side view of a second spring shown in one embodiment of the present application;

[0029] Fig.10 A cross-sectional view of a first bearing shown in an embodiment of the present application;

[0030] Fig.11 A cross-sectional view of a second bearing shown in an embodiment of the present application.

[0031] Figure numerals: 1. impeller; 2. first bearing; 21. outer diameter of the outer ring of the first bearing; 22. inner diameter of the outer ring of the first bearing; 3. second bearing; 31. outer diameter of the outer ring of the second bearing; 32. inner diameter of the outer ring of the second bearing; 4. rotating shaft; 5. first spring; 51. first cutting plane; 52. outer diameter of the first spring; 53. inner diameter of the first spring; 6. second spring; 61. second cutting plane; 62. outer diameter of the second spring; 63. inner diameter of the second spring; 7. blocking member; 71. first blocking member; 72. second blocking member; 8. magnet. DETAILED DESCRIPTION

[0032] In the description of this application, it should be noted that the terms "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed when in use, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply 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 a limitation on this application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0033] The utility model aims to provide a motor rotor assembly, in which two springs are arranged in the motor rotor assembly, the two springs are respectively in one-to-one contact with the sides of two bearings, and a certain pressure, namely, preload force, is applied to the two bearings along their axial direction, so as to solve the problem that the reverse thrust generated when the motor is running causes the preload force borne by the two bearings to be too large or too small, and the preload force becomes out of the originally designed range, thereby generating noise and affecting the bearing life.

[0034] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0035] See also Figure 1 The present application provides a motor rotor assembly, including an impeller 1, a first bearing 2, a second bearing 3, a rotating shaft 4, a first spring 5, a second spring 6 and a blocking member 7. The impeller 1 is connected to one end of the rotating shaft 4. The first bearing 2 and the second bearing 3 are both fixed to the rotating shaft 4 through inner ring sleeves, and the first bearing 2 and the second bearing 3 are sequentially arranged on one side of the impeller 1, that is, the first bearing 2 is located between the impeller 1 and the second bearing 3. In the prior art, a preload spring is usually directly arranged between the first bearing 2 and the second bearing 3, and the preload spring abuts against the outer ring of the first bearing 2 and the outer ring of the second bearing 3, so that a preload force is applied to the first bearing 2 and the second bearing 3. Since the impeller 1 generates high-speed airflow when the motor is running, the impeller 1 and the rotating shaft 4 are both subjected to the reverse thrust of the airflow. The inner ring of the bearing is fixed to the rotating shaft 4, so the inner ring of the bearing is also subjected to the reverse thrust. Originally, the preload force of the bearing is only generated by the preload spring acting on the outer ring of the bearing, and its preload effect is achieved by pushing the outer ring. When the reverse thrust acts on the inner ring of the bearing, if the direction of the reverse thrust on the inner ring of the bearing in the same bearing is consistent with the direction of the spring thrust on the outer ring of the bearing, part of the thrust of the spring is offset by the reverse thrust, which will weaken the preload effect of the preload spring and reduce the actual preload force of the bearing. If the direction of the reverse thrust on the inner ring of the bearing in the same bearing is opposite to the direction of the spring thrust on the outer ring of the bearing, the actual preload force obtained by the bearing is the superposition of the spring thrust and the reverse thrust, which enhances the preload effect of the bearing and increases the actual preload force of the bearing.

[0036] by Figure 2Taking the illustrated situation as an example, it is assumed that only one preload spring is provided between the left bearing 2 and the right bearing 3, and the preload spring abuts against the outer rings of the two bearings. The outer ring of the left bearing is subjected to the spring thrust to the left, so that the left bearing 2 obtains the initial preload force, and the outer ring of the right bearing is subjected to the spring thrust to the right, so that the right bearing 3 obtains the initial preload force. The reverse thrust generated by the rotation of the impeller 1 is to the left, and the reverse thrust pushes the inner rings of the two bearings to the left. At this time, both the inner ring and the outer ring of the left bearing 2 are subjected to the thrust to the left, and the initial preload force of the left bearing 2 is weakened. The actual preload force of the left bearing 2 is the initial preload force minus the reverse thrust, so the actual preload force of the left bearing 2 is reduced compared with the initial preload force. At this time, the outer ring of the right bearing 3 is subjected to the spring thrust to the right, so that the initial preload force is obtained, and the inner ring of the right bearing 3 is subjected to the reverse thrust to the left. Therefore, the actual preload force obtained by the right bearing 3 is the initial preload force plus the reverse thrust, that is, the actual preload force of the right bearing 3 is increased compared with the initial preload force. Based on the above analysis, it can be known that when only one preload spring is arranged between the left bearing 2 and the right bearing 3, the spring thrusts received by the outer rings of the left bearing and the right bearing are the same, that is, the initial preloads of the left bearing 2 and the right bearing 3 cannot be set separately. Even if the initial preloads are within the preset preload range at this time, when the reverse thrust in the left direction is applied to the inner rings of the two bearings, the actual preload of the left bearing 2 will be too small, and the actual preload of the right bearing 3 will be too large, so that the actual preloads of the two bearings are not within the preset preload range. A small bearing preload will cause motor noise, and a large bearing preload will cause the bearing to be subjected to large force, friction and heat, affecting the bearing life.

[0037] Therefore, the present application redesigns the motor rotor assembly, and uses two springs to design different initial preload forces for the two bearings respectively, so as to offset or superimpose the influence of the reverse thrust, so that the preload forces of the two bearings are within a reasonable range.

[0038] Reference Figure 1As shown, in the present application, the first spring 5 is sleeved on the rotating shaft 4, and one end of the first spring 5 abuts against the first bearing 2; the second spring 6 is sleeved on the rotating shaft 4, and one end of the second spring 6 abuts against the second bearing 3; the blocking member 7 is fixed to the rotating shaft 4, and one end of the first spring 5 away from the first bearing 2 and one end of the second spring 6 away from the second bearing 3 abut against the blocking member 7 respectively, and the blocking member 7 limits the first spring 5 and the second spring 6. Among them, the first spring 5 applies a first elastic force to the first bearing 2, and the second spring 6 applies a second elastic force to the second bearing 3. The first elastic force and the second elastic force are set independently of each other, that is, the first bearing 2 and the second bearing 3 are provided with initial preload by separate springs respectively, and will not affect each other. Moreover, through the setting of the blocking member 7, the specific values ​​of the first elastic force and the second elastic force can be set separately, so that the first bearing 2 and the second bearing 3 can obtain initial preloads of appropriate sizes respectively, so that the first elastic force and the second elastic force can be used to separately superimpose or offset the reverse thrust generated by the impeller 1, so that the actual preload of the first bearing 2 and the actual preload of the second bearing 3 are both within the preset preload range, avoiding the problem of the actual preload of the first bearing 2 and the second bearing 3 being too large or too small, thereby reducing noise and improving the service life of the bearings. Specifically, if the direction of the reverse thrust is consistent with the direction of the first elastic force or the second elastic force, that is, consistent with the direction of the initial preload, the reverse thrust weakens the initial preload, and the first elastic force or the second elastic force can be set to be greater than the preset preload, so that the actual preload reaching the preset preload is formed after the reverse thrust is offset during use; on the contrary, if the direction of the reverse thrust is opposite to the direction of the first elastic force or the second elastic force, that is, opposite to the direction of the initial preload, the reverse thrust strengthens the initial preload, and the first elastic force or the second elastic force can be set to be less than the preset preload, so that the actual preload reaching the preset preload is formed after the reverse thrust is superimposed during use. In some embodiments, the first spring 5 abuts against the outer ring of the first bearing 2, and the second spring 6 abuts against the outer ring of the second bearing 3, so that the first bearing 2 obtains the initial preload due to the first elastic force, and the second bearing 3 obtains the initial preload due to the second elastic force.

[0039] In some embodiments, the positions of the first bearing 2 and the second bearing 3 are fixed, and the setting of the first elastic force and the second elastic force can be achieved by setting the compression amount of the first spring 5 and the second spring 6 and selecting the elastic coefficients of the first spring 5 and the second spring 6. The setting of the compression amount of the first spring 5 and the second spring 6 is determined by selecting the setting position of the blocking member 7, and then the first elastic force and the second elastic force are determined respectively, so that the first elastic force and the second elastic force can be used separately to superimpose or offset the reverse thrust generated by the rotation of the impeller 1, and finally the first bearing 2 and the second bearing 3 obtain the actual preload within the preset preload range; in this embodiment, the thickness of the blocking member 7 can also be selected, and the thickness of the blocking member 7 along the spring compression direction can also affect the compression amount of the first spring 5 and the second spring 6.

[0040] Since the direction and magnitude of the reverse thrust generated by the rotation of the impeller 1 are known, and the setting positions of the first spring 5 and the second spring 6 are also known in advance, that is, the directions of the first elastic force and the second elastic force are also known in advance, it is possible to decide how to select the magnitudes of the first elastic force and the second elastic force based on this information. In addition, it should be noted that in actual applications, the preset preload is usually not an exact value. In fact, it is difficult to achieve an accurate preset preload based on error considerations. Therefore, the actual preload required by the first bearing 2 and the second bearing 3 in this application is within a preset preload range. As long as it is within this range, the actual preload is considered to be appropriate. Based on this, in some embodiments, the first elastic force and the second elastic force are separately set by the first spring 5 and the second spring 6 to respectively superimpose or offset the influence of the reverse thrust. The specific implementation method is:

[0041] The direction of the first elastic force or the second elastic force, that is, the direction of the initial preload obtained by the first bearing 2 or the direction of the initial preload obtained by the second bearing 3, is consistent with the direction of the reverse thrust generated by the rotation of the impeller 1. The first elastic force or the second elastic force is set to an upper limit value greater than the preset preload range to offset the reverse thrust generated by the rotation of the impeller 1. In the working state, the initial preload of the bearing is deducted from the reverse thrust to obtain the actual preload of the bearing, so that the actual preload obtained by the first bearing 2 or the second bearing 3 in the working state is within the preset preload range.

[0042] The direction of the first elastic force or the second elastic force, that is, the direction of the initial preload obtained by the first bearing 2 or the direction of the initial preload obtained by the second bearing 3, is opposite to the direction of the reverse thrust generated by the rotation of the impeller 1. The first elastic force or the second elastic force is set to a lower limit value less than the preset preload range, so as to superimpose the reverse thrust generated by the rotation of the impeller 1. In the working state, the initial preload of the bearing is added to the reverse thrust to obtain the actual preload of the bearing, so that the actual preload obtained by the first bearing 2 or the second bearing 3 in the working state is within the preset preload range.

[0043] The value of the initial preload force is determined according to the actual situation of the motor rotor assembly, that is, based on the specific numerical range of the preset preload force range and the magnitude of the reverse thrust measured experimentally. For example, in some embodiments, the reverse thrust measured experimentally is approximately 2N, and for the preset preload force range, the preset preload force range of products of different manufacturers is different, which is determined based on the actual situation.

[0044] In some embodiments, the motor rotor assembly also includes a magnet 8, which is passed through the rotating shaft 4 and is located at an end of the rotating shaft 4 away from the impeller 1. The first bearing 2 and the second bearing 3 are located between the impeller 1 and the magnet 8. The magnet 8 is used to stabilize the rotation of the motor rotor assembly and further reduce the vibration and noise generated during the operation of the impeller 1.

[0045] In the present application, there are various embodiments for setting the positional relationship between the blocking member 7, the first spring 5 and the second spring 6, and the various setting methods are as follows:

[0046] See also Figure 2 In one embodiment, a blocking member 7 and a spring are provided between the first bearing 2 and the second bearing 3, specifically:

[0047] The first spring 5 and the second spring 6 are located between the first bearing 2 and the second bearing 3, and the blocking member 7 is located between the first spring 5 and the second spring 6; the first spring 5 applies a first elastic force to the first bearing 2, and the second spring 6 applies a second elastic force to the second bearing 3, and the first elastic force is greater than the second elastic force. At this time, the first elastic force applied by the first spring 5 to the first bearing 2 is consistent with the direction of the reverse thrust, and the second elastic force applied by the second spring 6 to the second bearing 3 is opposite to the direction of the reverse thrust, so by manually adjusting or selecting the fixed position of the blocking member 7 on the rotating shaft 4 during assembly, the first elastic force is set to be greater than the second elastic force, so that the first elastic force can offset the reverse thrust in the working state of the rotor assembly, and the second elastic force can superimpose the reverse thrust in the working state of the rotor assembly, and finally the actual preload of the first bearing 2 and the second bearing 3 in the working state of the rotor assembly are both within the preset preload range. Specifically, in some embodiments, the first elastic force can be greater than the upper limit of the preset preload range, which is used to offset the reverse thrust in the working state of the rotor assembly, and the second elastic force can be less than the lower limit of the preset preload range, which is used to superimpose the reverse thrust in the working state of the rotor assembly.

[0048] When the motor rotor assembly is in operation, the impeller 1 runs at the rated speed to generate high-speed airflow, which will generate a reverse thrust on the motor. Specifically, the reverse thrust is applied to the inner ring of the bearing through the rotating shaft 4, and the reverse thrust is F3. In some embodiments, the first spring 5 applies the first elastic force to the outer ring of the first bearing 2 so that the first bearing 2 obtains an initial preload, and the second spring 5 applies the second elastic force to the outer ring of the second bearing 3 so that the second bearing 3 obtains an initial preload. Under the action of the reverse thrust, the initial preloads of the first bearing 2 and the second bearing 3 are changed, so it is necessary to adjust the first elastic force and the second elastic force to appropriate sizes respectively.

[0049] When the impeller 1 is not rotating, the first bearing 2 and the second bearing 3 have obtained an initial preload by adjusting the position of the blocking member 7. Therefore, when the impeller 1 is rotating at a high speed, the actual preload obtained by the first spring 5 is obtained by subtracting the reverse thrust from the first spring force, and the actual preload obtained by the second bearing 3 is obtained by adding the reverse thrust to the second spring force. In some embodiments, the reverse thrust is approximately 2N, so in this embodiment, the difference between the first spring force and the second spring force is in the range of 1-4N, so that the actual preloads finally obtained by the first bearing 2 and the second bearing 3 are both within the preset preload range, so that when the impeller 1 is running at a high speed, the preloads received by the first bearing 2 and the second bearing 3 are within the design requirements of the bearing body, thereby preventing the problem of motor noise caused by too small a bearing force or frictional heat caused by too large a bearing force affecting the bearing life.

[0050] This embodiment utilizes the characteristic that the blocking member is located between the first spring 5 and the second spring 6 and only uses one blocking member 7 to allow the first spring 5 and the second spring 6 to abut against each other, thereby saving cost, saving space and facilitating installation.

[0051] Furthermore, in this embodiment, the first elastic force is greater than the second elastic force, and the specific implementation methods are: the elastic coefficients of the first spring 5 and the second spring 6 are consistent, and the compression amount of the first spring 5 is greater than the compression amount of the second spring 6; or, the compression amounts of the first spring 5 and the second spring 6 are consistent, and the elastic coefficient of the first spring 5 is greater than the elastic coefficient of the second spring 6.

[0052] In another embodiment, the at least one blocking member 7 includes a first blocking member 71 and a second blocking member 72, both of which are fixed to the rotating shaft 4, the first blocking member 71 is located on the side of the first spring 5 away from the first bearing 2 for the first spring 5 to abut, and the second blocking member 72 is located on the side of the second spring 6 away from the second bearing 3 for the second spring 6 to abut.

[0053] In this embodiment, the blocking member 7 includes a first blocking member 71 and a second blocking member 72. When the first spring 5 and the second spring 6 are located between the first bearing 2 and the second bearing 3, and the blocking member 7 is located between the first spring 5 and the second spring 6, the first blocking member 71 can be abutted against the first spring 5, and the second blocking member 72 can be abutted against the second spring 6. In this embodiment, the specific implementation methods of the position setting of the first blocking member 71 and the first spring 5, the second blocking member 72 and the second spring 6 also include the following:

[0054] (1) See Figure 3 A blocking member 7 and a spring are respectively arranged on the side of the two bearings facing away from each other. Specifically, the first spring 5 and the first blocking member ring 71 are located between the first bearing 2 and the impeller 1, and the second spring 6 and the second blocking member 72 are located on the side of the second bearing 3 away from the first bearing 2.

[0055] At this time, since the direction of the first elastic force is opposite to the direction of the reverse thrust, and the direction of the second elastic force is consistent with the direction of the reverse thrust, the first elastic force is smaller than the second elastic force, and the first elastic force is used to superimpose the reverse thrust generated by the rotation of the impeller 1, and the second elastic force is used to offset the reverse thrust generated by the rotation of the impeller 1, so that the actual preload force of the first bearing 2 and the second bearing 3 are both within the preset preload force range. Further, in some implementations of this embodiment, the first elastic force can be specifically set to a lower limit value less than the preset preload force range, and the second elastic force can be set to a higher upper limit value than the preset preload force range. In this embodiment, the difference between the first elastic force and the second elastic force ranges from 1 to 4 N, and the reverse thrust is approximately 2 N.

[0056] (2) See Figure 4, the first spring 5 and the first blocking member 71 are arranged between the first bearing 2 and the impeller 1, and the second spring 6 and the second blocking member 72 are arranged between the first bearing 2 and the second bearing 3; at this time, since the directions of the first elastic force and the second elastic force are opposite to the directions of the reverse thrust, the first elastic force and the second elastic force are equal, and are both used to superimpose the reverse thrust generated by the rotation of the impeller 1 in the working state of the rotor assembly, so that the actual preload force of the first bearing 2 and the second bearing 3 are both within the preset preload force range. Further, in some implementations of this embodiment, the first elastic force and the second elastic force can be set to be less than the lower limit value of the preset preload force range.

[0057] (3) See Figure 5 The first spring 5 and the first blocking member 71 are arranged between the first bearing 2 and the second bearing 3 , and the second spring 6 and the second blocking member 72 are arranged on the side of the second bearing 3 away from the first bearing 2 .

[0058] At this time, since the directions of the first elastic force and the second elastic force are consistent with the direction of the reverse thrust, the first elastic force and the second elastic force are equal, and are both used to offset the reverse thrust generated by the rotation of the impeller 1 when the rotor assembly is in working state, so that the actual preload force of the first bearing 2 and the second bearing 3 are both within the preset preload force range. Further, in some implementations of this embodiment, the first elastic force and the second elastic force can be set to be greater than the upper limit of the preset preload force range.

[0059] See also Figure 6-7 In one embodiment of the present application, in order to make the first bearing 2 and the second bearing 3 bear force evenly, the two end faces of the first spring 5 and the second spring 6 are flattened to obtain cutting planes, so that the first spring 5 abuts against the first bearing 2 and the blocking member 7 respectively through the cutting plane to achieve close contact, and the second spring 6 also abuts against the second bearing 3 and the blocking member 7 respectively through the cutting plane to achieve close contact.

[0060] Moreover, in the present embodiment, the end of the first spring 5 has a first cutting plane 51; the end of the second spring 6 has a second cutting plane 61, which increases the contact area between the first spring 5 and the outer ring of the first bearing 2 and the blocking member 7, and increases the contact area between the second spring 6 and the outer ring of the second bearing 3 and the blocking member 7, so that the first spring 5 and the second spring 6 will not shake or misalign after being compressed, and the preload force of the first spring 5 and the second spring 6 is effectively guaranteed.

[0061] See also Figure 8-11In one embodiment of the present application, in order to further ensure effective contact between the spring and the outer ring of the bearing, one end of the first spring 5 is pressed against the outer ring of the first bearing 2, and one end of the second spring 6 is pressed against the outer ring of the second bearing 3, and the other ends of the first spring 5 and the second spring 6 are pre-tightened on the blocking member 7, and the outer diameter of the blocking member 7 is smaller than the outer diameter of the outer ring of the first bearing 2 and the second bearing 3; and the outer diameter 52 of the first spring is smaller than the outer diameter 21 of the outer ring of the first bearing, and the inner diameter 53 of the first spring is larger than the inner diameter 22 of the outer ring of the first bearing; the outer diameter 62 of the second spring is smaller than the outer diameter 31 of the outer ring of the second bearing, and the inner diameter 63 of the second spring is larger than the inner diameter 32 of the outer ring of the second bearing; thereby ensuring effective contact between the first spring 5 and the outer ring of the first bearing 2, and the second spring 6 and the outer ring of the second bearing 3.

[0062] The utility model adopts two springs to apply preload forces to two bearings respectively to offset the influence of the reverse thrust generated when the motor rotates. The utility model has a simple structure and low cost and can be used on various household appliances such as hair dryers and fans as needed.

[0063] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0064] It should be noted that, in the absence of conflict, the features in the embodiments of this application may be combined with each other.

[0065] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A motor rotor assembly, comprising: Rotating shaft; an impeller connected to one end of the rotating shaft; The first bearing and the second bearing are both fixed to the rotating shaft through inner ring sleeve connection, and the first bearing is located between the impeller and the second bearing; It is characterized by further comprising: A first spring, sleeved on the rotating shaft, one end of the first spring abutting against the first bearing; A second spring, sleeved on the rotating shaft, one end of the second spring abutting against the second bearing; At least one blocking member is fixed to the rotating shaft, and one end of the first spring away from the first bearing and one end of the second spring away from the second bearing are respectively in contact with the blocking member; The first elastic force applied by the first spring to the first bearing and the second elastic force applied by the second spring to the second bearing are independently arranged.

2. The motor rotor assembly according to claim 1, characterized in that: The first spring and the second spring are located between the first bearing and the second bearing, and the blocking member is located between the first spring and the second spring; Wherein, the first elastic force is greater than the second elastic force.

3. The motor rotor assembly according to claim 1, characterized in that: The at least one blocking member includes a first blocking member and a second blocking member. The first blocking member is located at a side of the first spring away from the first bearing for the first spring to abut against. The second blocking member is located at a side of the second spring away from the second bearing for the second spring to abut against.

4. The motor rotor assembly according to claim 3, characterized in that: The first spring and the first blocking member are located between the first bearing and the impeller, and the second spring and the second blocking member are located on a side of the second bearing away from the first bearing; Wherein, the first elastic force is smaller than the second elastic force.

5. The motor rotor assembly according to claim 3, characterized in that: The first spring and the first blocking member are located between the first bearing and the impeller, and the second spring and the second blocking member are located between the first bearing and the second bearing; Wherein, the first elastic force and the second elastic force are equal.

6. The motor rotor assembly according to claim 3, characterized in that: The first spring and the first blocking member are located between the first bearing and the second bearing, and the second spring and the second blocking member are located on a side of the second bearing away from the first bearing; Wherein, the first elastic force and the second elastic force are equal.

7. The motor rotor assembly according to claim 2 or 4, characterized in that: The difference between the first elastic force and the second elastic force ranges from 1N to 4N.

8. The motor rotor assembly according to claim 1, characterized in that: The ends of the first spring and the second spring both have cutting planes, and the first spring abuts against the first bearing and the blocking member respectively through the cutting planes; the second spring abuts against the second bearing and the blocking member respectively through the cutting planes.

9. The motor rotor assembly according to claim 1, characterized in that: The outer diameter of the first spring is smaller than the outer diameter of the outer ring of the first bearing, and the inner diameter of the first spring is larger than the inner diameter of the outer ring of the first bearing, so that the first spring abuts against the outer ring of the first bearing; The outer diameter of the second spring is smaller than the outer diameter of the second bearing outer ring, and the inner diameter of the second spring is larger than the inner diameter of the second bearing outer ring, so that the second spring abuts against the outer ring of the second bearing.

10. The motor rotor assembly according to claim 2, characterized in that: The elastic coefficients of the first spring and the second spring are consistent, and the compression amount of the first spring is greater than the compression amount of the second spring; or, the compression amounts of the first spring and the second spring are the same, and the elastic coefficient of the first spring is greater than the elastic coefficient of the second spring.

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