Electric grinding spindle

Abstract

The utility model relates to machining equipment, in particular to a grinding electric spindle. A grinding electric spindle comprises a shell, a core shaft is installed in the shell through a plurality of sets of bearings, a rotor is fixed to the tail end of the core shaft in an interference fit mode, a stator matched with the rotor is arranged on the inner side of the shell, the rotor does not make contact with the stator, a gap exists between the front end of the shell and the front end of the core shaft, and a connecting rod is installed at the front end of the core shaft. The motorized spindle for grinding the small-diameter deep hole solves the problems that a mechanical shaft for grinding the small-diameter deep hole is low in rotating speed and low in grinding efficiency, the motorized spindle is adopted, the precise angular contact bearings are matched in multiple rows, and the rotating precision and rigidity of the spindle are high.

Description

Technical Field

[0001] The utility model relates to processing equipment, in particular to a grinding electric spindle. Background Art

[0002] During the process of part processing, grinding is a very important process. Especially for precision parts, grinding can ensure the high-precision dimensions and surface quality of the parts. Grinding is divided into surface grinding, external cylindrical grinding and internal cylindrical grinding. Especially for internal round holes, the diameter is relatively small and the grinding depth is deep. In this case, the front end of the grinding spindle needs to be extended longer and have better rigidity, and the spindle speed needs to be high to improve the grinding efficiency and quality. At present, mechanical shafts are mainly used for grinding in the market, and the method of adding an extension rod is adopted to realize the grinding of small-diameter deep holes. Due to belt drive, the mechanical shaft has a low rotational speed. The extension rod is too long, with poor rigidity, low grinding efficiency and poor grinding quality. Even the grinding of deep and long holes cannot be completed.

[0003] In view of the above defects, the designer actively conducts research and innovation in order to create a grinding electric spindle, making it more valuable in industrial applications. Summary of the Utility Model

[0004] In order to solve the above technical problems, the purpose of the utility model is to provide a grinding electric spindle.

[0005] A grinding electric spindle of the utility model includes a housing. A core shaft is installed in the housing through multiple groups of bearings. A rotor is fixed to the tail end of the core shaft by interference fit. A stator that cooperates with the rotor is arranged inside the housing. There is no contact between the rotor and the stator. There is also a gap between the front end of the housing and the front end of the core shaft. A connecting rod is installed at the front end of the core shaft.

[0006] For this kind of grinding electric spindle, the tail end of the core shaft is provided with rotational power by the stator and the rotor, so that the core shaft rotates. A connecting rod is fixed to the front end of the core shaft, and the connecting rod is used to install a grinding tool, which is convenient for deep hole grinding.

[0007] Furthermore, there is a first stepped surface that contracts inward at the front end of the core shaft. The front and tail ends of the first stepped surface and the housing are respectively a front bearing group and a rear bearing group.

[0008] The first stepped surface of the core shaft and the housing are supported by the front bearing group and the rear bearing group, facilitating the rotation of the core shaft.

[0009] Furthermore, there are an inner spacer and an outer spacer between the front bearing group and the rear bearing group. The inner spacer is attached to the core shaft, and the outer spacer is attached to the inner side wall of the housing.

[0010] The inner spacer and the outer spacer serve to increase the span between the bearings and enhance the rigidity of the bearings.

[0011] Furthermore, the middle part of the core shaft is a second step surface, and the transition end surface between the first step surface and the second step surface and the end surface in the middle part of the shell are respectively provided with an inner gasket and an outer gasket.

[0012] The transition position between the first step surface and the second step surface serves the purpose of auxiliary support and limitation through the inner gasket and the outer gasket, which facilitates the control of the relative position of the core shaft, and the assembly accuracy of the core shaft is adjusted by setting different thicknesses of the inner gasket and the outer gasket.

[0013] Furthermore, a bearing seat is fixed at the rear end of the shell by bolts, the rear end of the core shaft is a third step surface, and a rear end bearing group is arranged between the bearing seat and the third step surface.

[0014] A useful bearing seat and a tail end bearing group are installed between the third step surface at the tail end of the core shaft and the housing to limit the tail end of the core shaft and ensure the running accuracy.

[0015] Furthermore, the rear end of the mandrel is provided with a threaded section, and the locking nut is screwed into the threaded section and pressed against the rear end bearing assembly to complete the locking of the mandrel.

[0016] The tail end of the core shaft is tightened and locked by means of a locking nut, thereby limiting the tail end to the tail end bearing group.

[0017] Furthermore, an end cover is fixed on the bearing seat by bolts.

[0018] The end cover is fixed to the outer end of the bearing seat by bolts, which serves the purpose of sealing the shell and improving the dust and chip prevention effect

[0019] Through the above scheme, the present invention has at least the following advantages: this electric spindle for grinding small diameter deep holes solves the problems of low rotation speed and low grinding efficiency of mechanical shafts for grinding small diameter deep holes. The electric spindle uses a multi-row assembly of precision angular contact bearings, and the spindle has high rotation accuracy and high rigidity.

[0020] The motor stator and rotor are built-in, without intermediate transmission links such as belts and gears, and can achieve high speed. Compared with the mechanical spindle, the electric spindle has large power torque and high speed. For mass-produced parts, it has high grinding efficiency and high surface quality of the ground parts. The electric spindle is easy to install and disassemble on the grinding machine, and the spindle has a long service life.

[0021] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present utility model, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0023] Figure 1 is a structural schematic diagram of the present utility model;

[0024] In the figure, 1 is the housing, 2 is the mandrel, 3 is the rotor, 4 is the stator, 5 is the connecting rod, 6 is the first stepped surface, 7 is the front bearing group, 8 is the rear bearing group, 9 is the inner spacer, 10 is the outer spacer, 11 is the second stepped surface, 12 is the inner washer, 13 is the outer washer, 14 is the bearing seat, 15 is the third stepped surface, 16 is the tail-end bearing group, 17 is the locking nut, and 18 is the end cover. Detailed implementation manners

[0025] The following will further describe in detail the specific implementation manners of the present utility model in conjunction with the drawings and embodiments. The following embodiments are used to illustrate the present utility model, but are not used to limit the scope of the present utility model.

[0026] See Figure 1 , which is a cross-section of the present invention. Its housing 1 is a metal tubular structure. The front end of the mandrel 2 extends out of the housing 1 and is locked and fixed by means of a front end cover and bolts to lock the front end of the mandrel 2. A connecting rod 5 is installed in the end face through hole at the front end of the mandrel 2, and the connecting rod 5 is connected to the grinding tool, facilitating the tool to extend into the deep hole for grinding operation. A rotor 3 is fixed on the mandrel 2, and a stator 4 is fixed at a position corresponding to the rotor 3 on the inner side wall of the housing 1. Under the cooperation of the rotor 3 and the stator 4, the mandrel 2 can rotate highly to meet the grinding requirements.

[0027] The front end of the mandrel 2 is the first stepped surface 6. Two front bearing groups 7 and rear bearing groups 8 are separated between the first stepped surface 6 and the housing 1. The two bearing groups can provide support for the front part of the mandrel 2, facilitating the rotation of the mandrel 2 in the housing 1.

[0028] There are an inner spacer 9 and an outer spacer 10 between the front bearing group 7 and the rear bearing group 8. The inner spacer 9 fits on the mandrel 2 and also fits on the inner rings of the corresponding bearings of the front bearing group 7 and the rear bearing group 8. The outer spacer 10 fits on the outer rings of the corresponding bearings of the front bearing group 7 and the rear bearing group 8. In this way, it can not only play the bearing span but also increase the rigidity of the bearings without affecting the rotation of the bearings.

[0029] There is a second step surface 11 in the middle of the mandrel 2. At the transition position between the first step surface 6 and the second step surface, there are an inner washer 12 and an outer washer 13. The inner washer 12 contacts the mandrel 2 and can contact the inner ring of the bearing in the rear bearing group 8. The outer washer 13 contacts the housing 1 and also contacts the outer ring of the bearing in the rear bearing group 8, facilitating contact with the rear bearing group 8 and serving the purpose of auxiliary support and positioning. By adjusting the thicknesses of the inner washer 12 and the outer washer 13, the installation position of the mandrel 2 can be adjusted to ensure the installation accuracy of the mandrel 2.

[0030] A bearing seat 14 is fixed at the tail end of the housing 1. A tail-end bearing group 16 is assembled between the bearing seat 14 and the third step surface 15 at the tail end of the mandrel 2. The tail-end bearing group 16 serves the purpose of auxiliary support and limit for the tail end of the mandrel 2.

[0031] There is a threaded section at the tail end of the mandrel 2. A locking nut 17 is screwed onto the threaded section. The annular structure on the outer circle of the locking nut 17 contacts the bearing seat 14 to provide tail-end support. The end cover 18 is tightened on the bearing seat 14 through bolts, and the end cover 18 serves a sealing function to prevent dust and impurities from entering the main shaft interior.

[0032] The working principle of the present utility model is as follows:

[0033] For this grinding electric main shaft, the overhang at the front end of the mandrel 2 is relatively long. The front end of the mandrel 2 is configured with the front bearing group 7 and the rear bearing group 8 in a back-to-back arrangement. The inner spacer 9 and the outer spacer 10 separate the front bearing group 7 from the rear bearing group 8, increasing the bearing span and the bearing rigidity. The inner washer 12 and the outer washer 13 are placed at the innermost end of the mandrel 2 to facilitate the adjustment of the main shaft accuracy. The front locking nut locks the inner ring of the front bearing group 7, and the front end cover presses the outer ring of the front bearing group 7 for rigid preloading. The motor stator 4 is hot-fitted into the housing 1 with an interference fit, and the rotor 3 is hot-fitted onto the mandrel 2 with an interference fit. The rear bearing group is configured in the bearing seat 14. The locking nut 17 locks the inner ring of the bearing in the tail-end bearing group 8, and the bearing gland presses on the outer ring of the tail-end bearing group 8 to serve a dust-proof function. The end cover 18 seals the rear end of the main shaft to prevent external water vapor, dust and other sundries from entering the bearing interior, increasing the service life of the main shaft. The connecting rod 5 is screwed tightly onto the front end of the mandrel 2, and the connecting rod 5 can be replaced according to different processing requirements.

[0034] Finally, several points should be noted: First, in the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. It can be a mechanical connection or an electrical connection, or it can be the communication inside two components. It can be directly connected. "Upper", "lower", "left", "right", etc. are only used to represent relative position relationships. When the absolute position of the described object changes, the relative position relationship may change;

[0035] Secondly: In the attached drawings of the disclosed embodiments of the present utility model, only the structures related to the disclosed embodiments are involved. For other structures, reference can be made to the general design. Without conflict, the same embodiment and different embodiments of the present utility model can be combined with each other;

[0036] Finally: The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present utility model.

Claims

1. A grinding electric spindle, comprising a housing (1), characterized in that: A core shaft (2) is installed in the housing (1) via multiple sets of bearings. A rotor (3) is fixed to the rear end of the core shaft (2) by means of interference fit. A stator (4) is provided on the inner side of the housing (1) to fit with the rotor (3). The rotor (3) and the stator (4) are not in contact with each other. There is also a gap between the front end of the housing (1) and the front end of the core shaft (2). A connecting rod (5) is installed at the front end of the core shaft (2).

2. The grinding electric spindle according to claim 1, characterized in that: The front end of the core shaft (2) has a first step surface (6) that contracts inwardly, and between the front end and the rear end of the first step surface (6) and the housing (1) are a front bearing group (7) and a rear bearing group (8), respectively.

3. The grinding electric spindle according to claim 2, characterized in that: An inner spacer (9) and an outer spacer (10) are provided between the front bearing group (7) and the rear bearing group (8), wherein the inner spacer (9) is fitted on the core shaft (2), and the outer spacer (10) is fitted on the inner wall of the housing (1).

4. The grinding electric spindle according to claim 3, characterized in that: The middle portion of the core shaft (2) is a second step surface (11), and an inner gasket (12) and an outer gasket (13) are respectively provided on the transition end surface between the first step surface (6) and the second step surface (11) and the end surface in the middle portion of the housing (1).

5. The grinding electric spindle according to claim 4, characterized in that: A bearing seat (14) is fixed at the rear end of the housing (1) by means of bolts, the rear end of the core shaft (2) is a third step surface (15), and a rear end bearing assembly (16) is provided between the bearing seat (14) and the third step surface (15).

6. The grinding electric spindle according to claim 5, characterized in that: The rear end of the mandrel (2) is provided with a threaded section, and the locking nut (17) is screwed into the threaded section and pressed against the rear end bearing assembly (16) to lock the mandrel (2).

7. The grinding electric spindle according to claim 6, characterized in that: An end cover (18) is fixed to the bearing seat (14) by bolts.

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