Low temperature motor shafting arrangement

Abstract

The utility model belongs to motor technical field especially, and it relates to low temperature motor shafting structure. One kind low temperature motor shafting structure, include: two end covers, set respectively in the both ends of casing, and two end covers are respectively set up in one bearing chamber, rotor, its rotation is arranged in the casing, two tolerance rings, respectively embed one bearing chamber, and be located between rotor bearing and bearing chamber. Through the setting of tolerance ring, can make low temperature motor shafting structure adapt to the size shrinkage caused by temperature change, easy to assemble, also can reduce the machining accuracy of bearing chamber base hole.

Description

Technical Field

[0001] This utility model belongs to the field of motor technology, and in particular relates to the shaft system structure of a low-temperature motor. Background Technology

[0002] In low-temperature environments, traditional motor shaft systems face numerous challenges. In traditional structures, the bearing and bearing housing are directly fitted together. When the temperature drops below -10°C, the metal material will shrink significantly, causing the clearance between the bearing and bearing housing to decrease or even disappear, resulting in a "bearing seizure" phenomenon.

[0003] Existing solutions mainly employ two approaches: One approach is to increase the initial clearance between the bearing and the bearing housing, but this will lead to increased vibration and noise in the motor when it is running at room temperature. Secondly, it is necessary to improve the machining accuracy of the bearing housing so that the dimensions after shrinkage can still maintain an appropriate clearance. This is because it is necessary to calculate the dimensional deviation caused by temperature changes, which significantly increases the manufacturing cost and manufacturing difficulty.

[0004] Therefore, in order to avoid the technical problems of existing solutions, there is an urgent need to provide another solution to the "bearing seizure" phenomenon caused by temperature drop.

[0005] It should be noted that the information disclosed in this background section is only for understanding the background technology of this application concept, and therefore, the above description is not considered to constitute information related to the technology. Utility Model Content

[0006] This disclosure provides at least one cryogenic motor shaft structure.

[0007] In a first aspect, embodiments of this disclosure provide a cryogenic motor shaft system structure, including: Two end caps are respectively located at both ends of the housing, and a bearing chamber is opened in each end cap; The rotor is rotatably mounted within the housing; Two tolerance rings, with wavy surfaces, are each embedded in one of the bearing chambers and located between the rotor bearing and the bearing chamber.

[0008] In one alternative embodiment, a notch is provided on the tolerance ring to facilitate insertion into the bearing housing.

[0009] In one alternative implementation, the tolerance ring is embedded inside the bearing housing by press-fitting or heat fitting.

[0010] In one alternative embodiment, the thickness of the tolerance ring is 1-3 mm.

[0011] In one alternative embodiment, a bearing housing and a tolerance ring embedded inside the bearing housing, the tolerance ring being elastic and having a wavy surface.

[0012] In one alternative embodiment, the tolerance ring is made of a nickel-titanium shape memory alloy.

[0013] In one alternative implementation, the wavy pattern of the tolerance ring is designed asymmetrically, with the crests biased toward the direction of rotation.

[0014] The beneficial effects of this utility model are that it provides a low-temperature motor shaft system structure. By embedding a tolerance ring between the bearing housing and the rotor bearing, the elastic properties of the tolerance ring itself can reduce the machining accuracy of the bearing housing base hole, thereby reducing manufacturing difficulty and cost. The wave-shaped surface of the tolerance ring is elastic and can adapt to the dimensional shrinkage caused by temperature changes, preventing the bearing from seizing at low temperatures and reducing the problem of increased starting current.

[0015] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description and the accompanying drawings.

[0016] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this utility model, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 A perspective view of the low-temperature motor shaft system structure provided in the embodiments of this disclosure; Figure 2 A front view of the tolerance ring provided in an embodiment of this disclosure.

[0019] In the picture: 1. Housing; 2. End cover; 20. Bearing chamber; 3. Rotor; 4. Tolerance ring; 40. Notch. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] In this document, when it is mentioned that a first component is located on a second component, this can mean that the first component can be directly formed on the second component, or that a third component can be inserted between the first and second components. Furthermore, in the accompanying drawings, the thickness of components may be exaggerated or reduced for the purpose of effectively describing the technical content.

[0022] In this document, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as “at least one of…” modify the entire list of elements when following a list of elements, rather than individual elements in the list. For example, the expression “at least one of a, b, and c” should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0023] The terminology used herein is for the purpose of describing specific exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may also be intended to include plural forms unless otherwise expressly stated herein. The terms “comprising,” “including,” and “having” are inclusive and thus specify the presence of features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein should not be construed as requiring them to be performed in the specific order discussed or shown, unless specifically identified as such. Additional or alternative steps may be employed.

[0024] As used herein, the phrases “in one embodiment,” “according to one embodiment,” “in some embodiments,” etc., generally refer to the fact that a particular feature, structure, or characteristic following the phrase can be included in at least one embodiment of this disclosure. Therefore, a particular feature, structure, or characteristic can be included in more than one embodiment of this disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms “example,” “exemplary,” etc., are used to “serve as an example, instance, or illustration.” Any implementation, aspect, or design described herein as “example” or “exemplary” is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. Rather, the use of the terms “example,” “exemplary,” etc., is intended to present concepts in a specific manner.

[0025] Research has revealed that traditional motor shaft systems face numerous challenges in low-temperature environments. In traditional structures, the bearing and bearing housing are directly fitted together. When the temperature drops below -10°C, the metal material shrinks significantly, causing the clearance between the bearing and bearing housing to decrease or even disappear, resulting in a "bearing seizure" phenomenon.

[0026] Existing solutions mainly employ two approaches: One approach is to increase the initial clearance between the bearing and the bearing housing, but this will lead to increased vibration and noise in the motor when it is running at room temperature. Secondly, it is necessary to improve the machining accuracy of the bearing housing so that the dimensions after shrinkage can still maintain an appropriate clearance. This is because it is necessary to calculate the dimensional deviation caused by temperature changes, which significantly increases the manufacturing cost and manufacturing difficulty.

[0027] Therefore, how to solve the "bearing seizure" phenomenon caused by temperature drop is a technical problem that urgently needs to be solved in this field.

[0028] The defects in the above solutions and the reasons for their occurrence are the results of the inventors' practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in this disclosure should be considered as the inventors' contributions to this disclosure.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] The following detailed description, with reference to the accompanying drawings, describes some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0031] like Figure 1 As shown, at least one embodiment provides a cryogenic motor shaft system structure, including: The housing 1 is made of high-strength cast iron, with end caps 2 at each end. Bearing chambers 20 are machined within the end caps 2, and the diameter tolerance of the bearing chambers 20 can be relaxed to IT8 grade, significantly reducing machining difficulty compared to the traditional IT6 grade. The rotor 3 is mounted within the housing 1 via bearings, specifically deep groove ball bearings, model 6205. A tolerance ring 4 is positioned between the bearing and the bearing chamber 20, and is pressed into the bearing chamber 20. Each tolerance ring 4 is embedded within one of the bearing chambers 20 and is located between the rotor 3 bearing and the bearing chamber 20. The thickness of the tolerance ring 4 is 1-3 mm. More specifically, the tolerance ring 4 has a thickness of 2 mm, is made of 65Mn spring steel, and has undergone quenching and tempering treatment, with a hardness controlled at HRC42-45.

[0032] like Figure 2 As shown, the tolerance ring 4 has a wavy texture on its surface, with a crest height of 0.3 mm and a wave pitch of 5 mm. This structure allows the ring to have an elastic deformation of 0.2-0.5 mm in the radial direction. A 3 mm wide notch 40 is cut into the circumference of the tolerance ring 4. During installation, the ring can be slightly opened using a special tool and then inserted into the bearing housing 20. After installation, the gap at the notch 40 is controlled to be within 0.5 mm.

[0033] In this embodiment, another method for installing the tolerance ring 4 is provided, specifically: the end cover 2 is heated to 150°C and held at that temperature for 30 minutes; the tolerance ring 4 at room temperature is quickly placed into the bearing chamber 20; after naturally cooling to room temperature, the tolerance ring 4 and the bearing chamber 20 form an interference fit. This installation method ensures more uniform contact between the mating surfaces and is particularly suitable for large-size motors (frame size 160 and above). The tolerance ring 4 installed by heat fitting can be without the notch 40, forming a complete annular structure.

[0034] In this embodiment, a tolerance ring 4 with an alternative structure is provided, which can employ a multi-layer composite structure: an inner layer of 0.5mm thick copper alloy, providing good thermal conductivity and wear resistance; a middle layer of 1mm thick spring steel, providing primary elastic support; and an outer layer of 0.3mm thick polytetrafluoroethylene coating, reducing the coefficient of friction. This composite structure maintains good elasticity even at -60℃, while reducing the coefficient of friction by 40% compared to a pure metal structure. It is particularly suitable for applications with frequent start-stop cycles.

[0035] In this embodiment, a tolerance ring with an alternative structure is also provided. The tolerance ring 4 is made of nickel-titanium shape memory alloy. The wavy pattern of the tolerance ring 4 adopts an asymmetrical design, with the crests biased towards the direction of rotation.

[0036] At least one embodiment provides a cryogenic motor shaft system structure, including: The bearing housing 20 and the tolerance ring 4 embedded inside the bearing housing 20, the tolerance ring 4 being elastic and having a wavy surface.

[0037] The working principle of this invention is based on the elastic deformation characteristics of the tolerance ring 4: At room temperature: the tolerance ring 4 and the bearing housing 20 have a slight interference fit (interference of 0.02-0.05mm) to ensure smooth motor operation; When the temperature drops: the metal material shrinks, but the tolerance ring 4 compensates for the shrinkage through elastic deformation, maintaining the appropriate clearance between the bearing and the bearing housing 20; In extreme cases: when a sudden drop in temperature causes the shrinkage to exceed the design value, the wave-shaped structure of tolerance ring 4 can undergo plastic deformation to prevent the bearing from seizing and protect the motor.

[0038] This utility model has the following significant advantages: Reduced processing costs: The machining accuracy requirement for bearing housing 20 has been reduced from IT6 to IT8, greatly reducing processing time; Wide range of applications: By adjusting the parameters of tolerance ring 4, it can adapt to a temperature range of -100℃ to +150℃; Easy maintenance: Tolerance ring 4 can be replaced separately, reducing maintenance costs.

[0039] The following points should be noted when implementing this utility model: The installation of tolerance ring 4 should be carried out in a clean environment to prevent impurities from entering the mating surface. For different temperature application scenarios, tolerance ring 4 of appropriate material should be selected. After installation, at least 5 temperature cycle tests from -40℃ to room temperature should be performed to confirm stable performance. The elasticity of tolerance ring 4 should be checked regularly, and it is recommended to check it once every 5000 hours of operation. When replacing bearings, it is recommended to replace tolerance ring 4 at the same time to ensure the best fit.

[0040] In addition to the above embodiments, the present invention may also have the following alternative embodiments: The tolerance ring 4 can adopt a segmented structure, consisting of 3-4 arc segments connected by snap-fit; the wavy pattern can be replaced with other periodic patterns such as sawtooth or sine; the material can be beryllium bronze, titanium alloy or other high-elasticity metals; a temperature sensor can be embedded in the tolerance ring 4 to monitor the bearing temperature in real time; for ultra-large motors, multiple tolerance rings 4 can be arranged in parallel.

[0041] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0042] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence unless expressly indicated herein. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed above may be referred to as the second element, component, region, layer, or segment.

[0043] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A low-temperature motor shaft system structure, characterized in that, include: Two end caps (2) are respectively set at both ends of the housing (1), and a bearing chamber (20) is opened in each end cap (2); The rotor (3) is rotatably disposed within the housing (1); Two tolerance rings (4) have wavy surfaces and are respectively embedded in one of the bearing chambers (20) and located between the rotor (3) bearing and the bearing chamber (20).

2. The cryogenic motor shaft system structure as described in claim 1, characterized in that, A notch (40) is provided on the tolerance ring (4) so ​​as to be embedded in the bearing chamber (20).

3. The cryogenic motor shaft system structure as described in claim 1, characterized in that, The tolerance ring (4) is embedded inside the bearing chamber (20) by pressing or heat fitting.

4. The cryogenic motor shaft system structure as described in claim 1, characterized in that, The thickness of the tolerance ring (4) is 1-3 mm.

5. A low-temperature motor shaft system structure, characterized in that, include: The bearing housing (20) and the tolerance ring (4) embedded inside the bearing housing (20), the surface of the tolerance ring (4) having a wave-like feature.

6. The cryogenic motor shaft system structure as described in claim 5, characterized in that, The tolerance ring (4) is made of nickel-titanium shape memory alloy material.

7. The cryogenic motor shaft system structure as described in claim 5, characterized in that, The wavy pattern of the tolerance ring (4) adopts an asymmetrical design, with the peaks biased towards the rotation direction.

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