Three-bearing motor for improving rigidity of cantilever beam structure
By adopting a three-bearing support structure in a three-bearing motor, the vibration problem caused by rotor imbalance and centrifugal force in the cantilever beam structure is solved, thereby improving the rigidity and stability of the motor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGZHOU FULLINGMOTOR
- Filing Date
- 2025-09-03
- Publication Date
- 2026-07-24
AI Technical Summary
Conventional three-bearing motors in cantilever beam structures experience large vibrations due to rotor imbalance and centrifugal force, resulting in low axial and radial loads and low structural rigidity.
The structure employs a three-bearing support structure, including a front bearing, a first rear bearing, and a second rear bearing. Through the interaction between the stator assembly and the rotor assembly, the axial and radial load-bearing capacity is increased, thereby improving the rigidity of the cantilever beam structure.
The three-bearing support structure improves the structural rigidity of the motor, reduces the instability caused by the cantilever beam design, and enhances the stability and vibration resistance of the rotor.
Smart Images
Figure CN224555347U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of motor technology, and in particular to a three-bearing motor for improving the rigidity of cantilever beam structures. Background Technology
[0002] Conventional motors typically have two bearings, and the cantilever beam structure means that the rotor is supported at only one end during operation. When the length-to-diameter ratio of the motor is too large and the internal space is compact, the motor is prone to unstable operation, and may even cause friction between the stator and rotor, resulting in the motor failing to work properly. Therefore, a three-bearing motor is required.
[0003] In the prior art, patent CN220139368U discloses a three-bearing motor, including a housing. A first bearing is provided on one side of the inner wall of the housing, and a motor shaft is rotatably connected to the inner wall of the first bearing. A second bearing is provided on the other side of the inner wall of the housing and is rotatably connected to the motor shaft. A rotor is provided on the outer wall of the motor shaft and located inside the housing. A stator is provided on the inner wall of the housing, and the rotor is placed in the inner ring of the stator. A mounting cover is bolted to one side of the housing. A sliding groove is formed on the outer wall of the mounting cover. A slider is slidably installed inside the sliding groove. A connecting rod is rotatably installed on one side of the slider. A mounting tube is rotatably installed on the other end of a plurality of connecting rods. A third bearing is provided inside the mounting tube.
[0004] The above structure avoids the need to replace the entire unit if the third bearing is damaged. However, during motor operation, due to factors such as rotor imbalance and centrifugal force, it is more prone to large vibrations. The axial and radial loads that the whole machine can withstand are relatively small, resulting in low rigidity and strength of the motor structure. Utility Model Content
[0005] In view of this, the purpose of this utility model is to propose a three-bearing motor that improves the rigidity of the cantilever beam structure, so as to solve the problem that the motor structure has low rigidity and strength because the rotor is more prone to large vibrations due to unbalanced forces and centrifugal forces, and the whole machine can only withstand small axial and radial loads.
[0006] To achieve the above objectives, this utility model provides a three-bearing motor for improving the rigidity of a cantilever beam structure, including a front cover, a front bearing fixedly mounted on one end of the front cover, and a rotating shaft passing through the interior of the front bearing; The end of the rotating shaft is fixedly connected to a rotor housing, the outside of the front end cover is provided with a stator assembly, and the inside of the rotor housing is fixedly installed with a rotor assembly corresponding to the stator assembly. The outer side and the end of the rotating shaft are respectively fitted with rear bearing one and rear bearing two. Rear bearing one is located at the other end of the front end cover, and rear bearing two is installed inside the rotor housing.
[0007] Preferably, the distance between the first rear bearing and the second rear bearing is 2mm to 6mm.
[0008] Preferably, the inner diameter of the second rear bearing is smaller than that of the first rear bearing, the outer steel ring of the first rear bearing is tightly fitted, and the inner steel ring of the first rear bearing is loosely fitted to the shaft of the first rear bearing, and glue is provided between the first rear bearing and the rotating shaft.
[0009] Preferably, the end of the rotating shaft is a stepped shaft structure, and the end of the rotating shaft and the rotor housing are knurled interference fit, and there is glue between the rotating shaft and the rotor housing.
[0010] Preferably, adhesive is applied between the inner steel ring of the second rear bearing and the shaft of the second rear bearing, and the outer steel ring of the second rear bearing is cold-pressed for tight fitting.
[0011] Preferably, the inner and outer steel rings of the front bearing are fully loosely fitted, and wave washers are provided between the front bearing and the front end cover and the rotating shaft.
[0012] The beneficial effects of this utility model are: The interaction between the rotating magnetic field generated by the stator assembly and the rotor assembly converts electromagnetic energy into mechanical energy, driving the rotor housing and the shaft fixed thereto to rotate. When the shaft rotates, the axial and radial loads that the whole machine can withstand are increased due to the support provided by the front bearing in the front cover, as well as the rear bearing one and the rear bearing two through the three bearings. This improves the rigidity and strength of the motor structure, but reduces the front bearing near the cantilever end, which is prone to fatigue wear, overheating and other problems. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0014] Figure 1 This is a schematic diagram of the overall internal structure of this utility model; Figure 2 This is a side view of the overall structure of this utility model; Figure 3 This is a three-dimensional exploded view of the overall structure of this utility model.
[0015] The markings in the diagram are: 1. Front cover; 2. Shaft; 3. Front bearing; 4. Rear bearing one; 6. Stator assembly; 7. Rotor assembly; 8. Rear bearing two; 9. Rotor housing. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments.
[0017] like Figure 1 , Figure 2 , Figure 3 As shown, a three-bearing motor for improving the rigidity of a cantilever beam structure includes a front cover 1, a front bearing 3 fixedly mounted on one end of the front cover 1, and a rotating shaft 2 passing through the interior of the front bearing 3. The rotor housing 9 is fixedly connected to the end of the rotating shaft 2, the stator assembly 6 is provided on the outside of the front cover 1, and the rotor assembly 7 corresponding to the stator assembly 6 is fixedly installed inside the rotor housing 9. The outer side and the end of the rotating shaft 2 are respectively fitted with rear bearing 4 and rear bearing 8. Rear bearing 4 is located at the other end of the front cover 1, and rear bearing 8 is installed inside the rotor housing 9.
[0018] In this embodiment, the electromagnetic energy is converted into mechanical energy through the interaction between the rotating magnetic field generated by the stator assembly 6 and the rotor assembly 7, which drives the rotor housing 9 and the shaft 2 fixed thereto to rotate. When the shaft 2 rotates, the front bearing 3 in the front cover 1, as well as the rear bearing 4 and the rear bearing 8, provide support through the three bearings, which increases the axial and radial loads that the whole machine can withstand, improves the rigidity of the motor structure, and reduces the problem of unstable operation caused by the cantilever beam design.
[0019] As one implementation method, such as Figure 1 , Figure 2 and Figure 3 As shown, the distance between rear bearing 4 and rear bearing 8 is 2mm to 6mm.
[0020] In this embodiment, when the distance between the first rear bearing 4 and the second rear bearing 8 is less than 2mm, the distance between the first rear bearing 4 and the second rear bearing 8 is too close, and the bearings do not effectively distribute the radial load of the motor. Moreover, the axial distance between the wound stator and the rotor housing is too close, and the creepage distance between the stator enameled wire and the bottom of the rotor housing is insufficient, which poses a risk of breakdown. When the distance between the first rear bearing 4 and the second rear bearing 8 is greater than 6mm, the axial structural space of the motor will increase, and the rotor inertia will increase, which is not conducive to flattening and low-cost design.
[0021] As one implementation method, such as Figure 1 and Figure 3 As shown, the inner diameter of the second rear bearing 8 is smaller than the inner diameter of the first rear bearing 4. The outer steel ring of the first rear bearing 4 is tightly fitted, while the inner steel ring of the first rear bearing 4 is loosely fitted with the shaft of the first rear bearing 4. Adhesive is provided between the first rear bearing 4 and the rotating shaft 2.
[0022] In this embodiment, the rear bearing 2 8 and rear bearing 1 4 solve the problems of fatigue wear and overheating that are prone to occur in the front bearing 3 near the cantilever end, thereby increasing the stability of rotor operation and improving the vibration and noise problems caused by the unbalanced force and centrifugal force of the rotor when the motor is running.
[0023] As one implementation method, such as Figure 1 and Figure 3 As shown, the end of the rotating shaft 2 is a stepped shaft structure, and the end of the rotating shaft 2 and the rotor housing 9 are knurled interference fit, and there is glue between the rotating shaft 2 and the rotor housing 9.
[0024] In this embodiment, in the rotor assembly 7 of the motor, the rotating shaft 2 and the rotor housing 9 adopt a knurled interference fit, and cold pressing and glue are used to assist in ensuring the bonding force. In addition, since the rotating shaft 2 is stepped, a central hole is opened at one end of the rotating shaft 2. This hole can play a preliminary centering and guiding role when the rotor housing 9 and the rotating shaft 2 are pressed together, ensuring the coaxiality of the rotor assembly 7.
[0025] Among them, the ratio of the overall motor body length to the overall motor outer diameter is 1.4 or more. When the length-to-diameter ratio is ≥1.4, the three-bearing scheme has obvious advantages. The larger the length-to-diameter ratio, the more obvious the advantages.
[0026] As one implementation method, such as Figure 3 As shown, the inner steel ring of the second rear bearing 8 is loosely fitted with adhesive, and the outer steel ring of the second rear bearing 8 is tightly fitted and cold-pressed.
[0027] In this embodiment, a second rear bearing 8 is added at the motor rotor assembly 7. The second rear bearing 8 adopts a method of tight-fitting cold pressing of the outer steel ring and loose-fitting glue application of the inner steel ring and shaft, which facilitates rotor assembly.
[0028] As one implementation method, such as Figure 1 , Figure 2 and Figure 3 As shown, the inner and outer steel rings of the front bearing 3 are fully loosely fitted, and there are wave pads between the front bearing 3 and the front cover 1 and the rotating shaft 2.
[0029] In this embodiment, the inner and outer steel rings of the front bearing 3 are fully loosened, and the axial preload is adjusted in conjunction with the wave pad.
[0030] Working principle: Before installation, in the rotor assembly 7 of the motor, the shaft 2 and the rotor housing 9 adopt a knurled interference fit, and cold pressing and glue are used to assist in ensuring the bonding force. In addition, since the shaft 2 is stepped, a center hole is opened at one end of the shaft 2. This hole can play a preliminary centering and guiding role when the rotor housing 9 and the shaft 2 are pressed together, ensuring the coaxiality of the rotor assembly 7. The interaction between the rotating magnetic field generated by the stator assembly 6 and the rotor assembly 7 converts electromagnetic energy into mechanical energy, driving the rotor housing 9 and the fixed shaft 2 to rotate. When the shaft 2 rotates, the front bearing 3 in the front cover 1, as well as the rear bearing 4 and the rear bearing 8, provide support through the three bearings, increasing the axial and radial loads that the whole machine can withstand. This improves the rigidity of the motor structure and reduces the problem of unstable operation caused by the cantilever beam design.
[0031] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples; within the framework of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in the details for the sake of brevity.
[0032] This utility model is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A three-bearing motor for improving the rigidity of a cantilever beam structure, comprising a front end cover (1), characterized in that, A front bearing (3) is fixedly installed at one end of the front cover (1), and a rotating shaft (2) runs through the interior of the front bearing (3); a rotor housing (9) is fixedly connected to the end of the rotating shaft (2); a stator assembly (6) is provided on the outside of the front cover (1), and a rotor assembly (7) corresponding to the stator assembly (6) is fixedly installed inside the rotor housing (9); a rear bearing first (4) and a rear bearing second (8) are respectively sleeved on the outside and the end of the rotating shaft (2), the rear bearing first (4) is located at the other end of the front cover (1), and the rear bearing second (8) is installed inside the rotor housing (9).
2. A three-bearing motor for improving the rigidity of a cantilever beam structure according to claim 1, characterized in that, The distance between the first rear bearing (4) and the second rear bearing (8) is 2mm to 6mm.
3. A three-bearing motor for improving the rigidity of a cantilever beam structure according to claim 1, characterized in that, The inner diameter of the second rear bearing (8) is smaller than the inner diameter of the first rear bearing (4). The outer steel ring of the first rear bearing (4) is tightly fitted, and the inner steel ring of the first rear bearing (4) is loosely fitted with the shaft of the first rear bearing (4). Adhesive is provided between the first rear bearing (4) and the rotating shaft (2).
4. A three-bearing motor for improving the rigidity of a cantilever beam structure according to claim 1, characterized in that, The end of the rotating shaft (2) is a stepped shaft structure, and the end of the rotating shaft (2) and the rotor housing (9) are knurled interference fit, and there is glue between the rotating shaft (2) and the rotor housing (9).
5. A three-bearing motor for improving the rigidity of a cantilever beam structure according to claim 1, characterized in that, The inner steel ring of the second rear bearing (8) is loosely fitted with adhesive, and the outer steel ring of the second rear bearing (8) is tightly fitted and cold-pressed.
6. A three-bearing motor for improving the rigidity of a cantilever beam structure according to claim 1, characterized in that, The inner and outer steel rings of the front bearing (3) are fully loosely fitted, and a wave pad is provided between the front bearing (3) and the front end cover (1) and the rotating shaft (2).