Bearing framework of electromechanical main shaft of high-speed automatic lathe

Abstract

The bearing framework comprises a shaft core, a front angular contact ball bearing, a front repairing and assembling spacer ring and a front nut are sequentially arranged at the position of a step at the right end of the shaft core from left to right in a sleeved mode, and the left end face of the front repairing and assembling spacer ring abuts against an inner ring of the front angular contact ball bearing. The front repairing spacer ring and the front angular contact ball bearing are arranged at the right end of the shaft core in a sleeving manner by a front nut in a threaded pressing manner; a first rear repair spacer ring, a rear angular contact ball bearing, a second rear repair spacer ring and a rear nut are sequentially arranged at a step at the left end of the shaft core from right to left in a sleeving mode, a bearing seat is arranged between the step of the first rear repair spacer ring and the step of the second rear repair spacer ring, and the inner wall of the bearing seat is attached to the outer wall of the rear angular contact ball bearing; a groove and a spring are arranged on one surface in the bearing seat, a spring backing ring is arranged at the free end of the spring, and the left end face of the spring backing ring abuts against the right end face of the rear angular contact ball bearing outer ring. The structure has high rigidity, high rotating speed and low thermal elongation, so that the processing stability of the main shaft is improved.

Description

Technical Field

[0001] This utility model belongs to the technical field of electric spindles for Swiss-type CNC lathes, and in particular relates to a bearing structure for a high-speed Swiss-type electric spindle. Background Technology

[0002] Among the existing spindle bearing configurations, the "3+2" configuration is a commonly used bearing architecture for spindles, consisting of three angular contact ball bearings at the front and two at the rear. However, angular contact ball bearings have relatively weak radial load-bearing capacity, resulting in poor radial rigidity of the spindle and making it unsuitable for heavy-load cutting. Furthermore, the "3+2" bearing architecture has a large span between the front and rear bearings, affecting the spindle's machining stability.

[0003] Therefore, we propose a high-speed Swiss-type electromechanical spindle bearing architecture. Utility Model Content

[0004] The purpose of this invention is to provide a high-speed Swiss-type electromechanical spindle bearing architecture to solve existing problems.

[0005] To solve the above-mentioned technical problems, this utility model is achieved through the following technical solution:

[0006] This utility model relates to a high-speed Swiss-type electromechanical spindle bearing structure, comprising a spindle core. At the right end of the spindle core, a front angular contact ball bearing, a front fitting spacer, and a front nut are sequentially fitted from left to right at the stepped end. The front angular contact ball bearing, the front fitting spacer, and the front nut are in close contact with each other. The left end face of the front fitting spacer abuts against the inner ring of the front angular contact ball bearing. The front nut secures the front fitting spacer and the front angular contact ball bearing to the right end of the spindle core using a threaded clamping method.

[0007] The left end of the shaft core is fitted with a rear fitting spacer ring one, a rear angular contact ball bearing, a rear fitting spacer ring two, and a rear nut sequentially from right to left at the stepped end. The rear fitting spacer ring one, the rear angular contact ball bearing, the rear fitting spacer ring two, and the rear nut are in close contact with each other. A bearing seat is provided between the steps of the rear fitting spacer ring one and the steps of the rear fitting spacer ring two. The inner wall of the bearing seat is in contact with the outer wall of the rear angular contact ball bearing. A groove is formed on one inner surface of the bearing seat. A spring is provided in the groove. A spring washer is provided at the free end of the spring. The left end face of the spring washer abuts against the right end face of the outer ring of the rear angular contact ball bearing.

[0008] The rear nut is used to fit the rear fitting spacer one, the rear angular contact ball bearing and the rear fitting spacer two onto the left end of the shaft core by threaded clamping.

[0009] Furthermore, the second post-fit spacer ring is secured to the bearing housing with screws.

[0010] Furthermore, both the front angular contact ball bearing and the rear angular contact ball bearing are two angular contact ball bearings; the front angular contact ball bearing and the rear angular contact ball bearing are arranged back to back.

[0011] This utility model has the following beneficial effects:

[0012] 1. High rigidity: The front-end angular contact ball bearing can withstand unidirectional axial loads. By selecting tandem angular contact ball bearings, the spindle can obtain high axial rigidity. By installing two sets of tandem angular contact ball bearings back to back and applying a certain preload for positioning and pre-tightening, the spindle can be positioned in both directions. Selecting 4 DBB angular contact ball bearings can also obtain high axial rigidity for the spindle.

[0013] II. High Speed: The maximum operating speed of a rolling bearing depends on its allowable operating temperature. Therefore, to increase the bearing speed, it is necessary to control the bearing temperature rise. However, the bearing temperature rise is related to the preload. The greater the preload, the greater the bearing rigidity, and the higher the temperature rise. To ensure the rigidity of the spindle without causing excessive bearing temperature rise, a solution is adopted that uses four angular contact ball bearings away from the motor heat source and supplemented by external cooling. This efficient centralized cooling improves the bearing temperature rise and enables the spindle to operate continuously and stably at high speeds.

[0014] 3. Low thermal expansion: The front end of the spindle is axially positioned in both directions, but as long as there is a temperature rise during operation, there will be thermal expansion and elongation of the spindle core. In order to prevent this thermal expansion of the spindle from significantly affecting the machining accuracy of the spindle, the thermal expansion is guided to the tail end of the spindle, and a cylindrical roller bearing that can allow a small amount of axial displacement is selected at the rear end. At the same time, the cylindrical roller bearing has good radial load capacity, which improves the overall radial rigidity of the spindle.

[0015] Of course, any product implementing this utility model does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a cross-sectional structural diagram of a high-speed Swiss-type electromechanical spindle bearing architecture.

[0018] The attached diagram lists the components represented by each number as follows:

[0019] 1. Front nut; 2. Front spacer ring; 3. Front angular contact ball bearing; 4. Rear spacer ring one; 5. Spring; 6. Spring washer; 7. Rear angular contact ball bearing; 8. Bearing housing; 9. Rear spacer ring two; 10. Rear nut; 11. Shaft core. Detailed Implementation

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

[0021] In the description of this utility model, it should be understood that the terms "upper", "middle", "outer", "inner", etc., which indicate orientation or positional relationship, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the components or elements 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.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within 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.

[0023] Please see Figure 1 As shown, this utility model is a high-speed Swiss-type electromechanical spindle bearing structure, including a spindle core 11. From left to right, a front angular contact ball bearing 3, a front fitting spacer 2, and a front nut 1 are sequentially fitted at the right end step of the spindle core 11. The front angular contact ball bearing 3, the front fitting spacer 2, and the front nut 1 are in close contact with each other. The left end face of the front fitting spacer 2 abuts against the inner ring of the front angular contact ball bearing 3. The front nut 1 is threaded to tighten the front fitting spacer 2 and the front angular contact ball bearing 3 onto the right end of the spindle core 11.

[0024] At the left end step of the shaft core 11, from right to left, a rear fitting spacer 4, a rear angular contact ball bearing 7, a rear fitting spacer 9, and a rear nut 10 are sequentially fitted. The rear fitting spacer 4, the rear angular contact ball bearing 7, the rear fitting spacer 9, and the rear nut 10 are in close contact with each other. A bearing seat 8 is provided between the step of the rear fitting spacer 4 and the step of the rear fitting spacer 9. The inner wall of the bearing seat 8 is in contact with the outer wall of the rear angular contact ball bearing 7. A groove is opened on one inner surface of the bearing seat 8. A spring 5 is provided in the groove. A spring washer 6 is provided at the free end of the spring 5. The left end face of the spring washer 6 abuts against the right end face of the outer ring of the rear angular contact ball bearing 7.

[0025] The rear nut 10 uses a threaded clamping method to fit the rear fitting spacer 4, the rear angular contact ball bearing 7, and the rear fitting spacer 9 onto the left end of the shaft core 11.

[0026] In one embodiment, the second spacer ring 9 is fastened to the bearing housing 8 by screws.

[0027] In one embodiment, both the front angular contact ball bearing 3 and the rear angular contact ball bearing 7 are two angular contact ball bearings; the front angular contact ball bearing 3 and the rear angular contact ball bearing 7 are arranged back to back.

[0028] It needs further explanation that the front end of this structure consists of a step on the shaft core 11 and a front fitting spacer 2, which serves as both front-end positioning and front-end protection. Next are two angular contact ball bearings, capable of withstanding forward axial loads. Following these are the front nut 1 for locking the front bearing assembly and the "motor rotor" for providing drive torque. The front nut 1 presses the front angular contact ball bearing 3 together, achieving bidirectional axial positioning of the front bearing assembly. Finally, the rear bearing assembly consists of a rear fitting spacer 1 4, a rear fitting spacer 2 9, a spring 5, a spring washer 6, a rear angular contact ball bearing 7, a bearing housing 8, and a rear nut 10. Their structural relationship is as follows: Figure 1 It is used to support the radial force at the tail end of the spindle, while also providing thermal extension space at the tail end of the spindle core.

[0029] This utility model represents an innovation in the bearing architecture of a high-speed Swiss-type electromechanical spindle;

[0030] 1. The front bearing span of the main spindle of this mechanism is relatively small. Under the same axial rigidity as the traditional 2+2 structure, the traditional structure mainly relies on the first two bearings for radial support, while this structure relies on four bearings for radial support. Therefore, the overall radial rigidity is larger, which improves the machining stability of the main spindle.

[0031] 2. The spindle using this structure has its front-end force-applying bearing far away from the motor's heat source, making the structure more compact and allowing for centralized cooling, thus reducing the temperature rise of the bearing.

[0032] 3. Because the bearing support point is located at the front and the rear end is a cylindrical roller bearing, this structure allows for a small amount of axial displacement of the inner and outer rings of the bearing, which causes the thermal elongation of the shaft core to extend towards the tail end, reducing the thermal elongation at the front end of the spindle and improving the machining accuracy of the spindle.

[0033] In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0034] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A high speed spindle motorized main shaft bearing architecture comprising a shaft core (11), characterized by: The front angular contact ball bearing (3), the front fitting spacer ring (2) and the front nut (1) are sequentially sleeved on the right end step of the shaft core (11) from left to right, and the front angular contact ball bearing (3), the front fitting spacer ring (2) and the front nut (1) are in close contact with each other; the left end surface of the front fitting spacer ring (2) abuts against the inner ring of the front angular contact ball bearing (3); the front nut (1) is in threaded compression mode to sleeve the front fitting spacer ring (2) and the front angular contact ball bearing (3) on the right end of the shaft core (11); The rear fitting spacer ring one (4), the rear angular contact ball bearing (7), the rear fitting spacer ring two (9) and the rear nut (10) are sequentially sleeved on the left end step of the shaft core (11) from right to left, and the rear fitting spacer ring one (4), the rear angular contact ball bearing (7), the rear fitting spacer ring two (9) and the rear nut (10) are in close contact with each other; the bearing seat (8) is arranged between the step of the rear fitting spacer ring one (4) and the step of the rear fitting spacer ring two (9), and the inner wall of the bearing seat (8) is attached to the outer wall of the rear angular contact ball bearing (7); a groove is formed in an inner surface of the bearing seat (8), a spring (5) is arranged in the groove, a spring washer (6) is arranged at the free end of the spring (5), and the left end surface of the spring washer (6) abuts against the right end surface of the outer ring of the rear angular contact ball bearing (7); The rear nut (10) is in threaded compression mode to sleeve the rear fitting spacer ring one (4), the rear angular contact ball bearing (7) and the rear fitting spacer ring two (9) on the left end of the shaft core (11).

2. A high-speed live tooling motorized spindle bearing architecture according to claim 1, wherein, The rear fitting spacer ring two (9) and the bearing seat (8) are locked by screws.

3. The bearing architecture for high speed motorized spindle of claim 1, wherein, The front angular contact ball bearing (3) and the rear angular contact ball bearing (7) are both two angular contact ball bearings; the front angular contact ball bearing (3) and the rear angular contact ball bearing (7) are arranged back to back.

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