Electric spindle for deep hole grinding

Abstract

The utility model relates to the technical field of electric spindles, in particular to an electric spindle for deep hole grinding. An electric spindle for deep hole grinding comprises a shell, a core shaft is movably installed in a cavity in the shell through a first bearing set, a second bearing set and a third bearing set, an extension rod is installed at the front end of the core shaft in a threaded hole mode, a first step face is arranged at the tail end of the core shaft, and a rotor is installed on the first step face in a heat fit mode. A stator seat is fixed at the tail end of the shell, and a stator is installed in the stator seat. The electric spindle for deep hole grinding solves the problems of low rotating speed and low grinding efficiency of a mechanical shaft for grinding small-diameter deep holes, adopts the electric spindle, uses the precise angular contact bearings in multi-row matching, and is high in rotating precision and rigidity.

Description

Technical Field

[0001] The utility model relates to the technical field of electric spindles, in particular to an electric spindle for deep hole grinding. Background Art

[0002] In the parts processing process, grinding is a very important process, especially for precision parts. Grinding can ensure the parts' high precision size and surface quality. Grinding is divided into surface grinding, external cylindrical grinding and internal cylindrical grinding. In particular, for internal holes, the diameter is relatively small and the grinding depth is deep. This requires the front end of the grinding spindle to be extended longer and have good rigidity, and the spindle speed must be high to improve the efficiency and quality of grinding. Currently, the main method used in the market is mechanical shaft grinding, and the grinding of small diameter deep holes is achieved by adding an extension rod. Due to the belt drive, the mechanical shaft has a low speed, the extension rod is too long, the rigidity is poor, the grinding efficiency is low, and the grinding quality is poor. It is even impossible to complete the grinding of long and deep holes. The heat generated by the motor stator is transmitted to the bearings, resulting in thermal elongation of the spindle and reduced grinding accuracy.

[0003] At present, deep hole processing has the following disadvantages:

[0004] 1. Existing deep hole grinding is basically mechanical axis and belt drive, with low speed and large vibration, low grinding efficiency and poor quality assurance.

[0005] 2. Some machines use electric spindles with a long rod at the front end, which has low rigidity and cannot grind extra-long deep holes.

[0006] 3. The electric spindle is radially configured with a motor stator and rotor. The heat generated by the motor has a great impact on the machining accuracy and stability of the electric spindle, reducing the service life of the spindle.

[0007] In view of the above-mentioned defects, the designers have actively carried out research and innovation in order to create an electric spindle for deep hole grinding to make it more valuable for industrial use. Utility Model Content

[0008] In order to solve the above technical problems, the purpose of the utility model is to provide an electric spindle for deep hole grinding.

[0009] The utility model discloses an electric spindle for deep hole grinding, comprising a shell, a core shaft movably mounted in a cavity inside the shell through a first bearing group, a second bearing group and a third bearing group, an extension rod being mounted on the front end of the core shaft through a threaded screw hole, a first step surface being provided at the rear end of the core shaft, a rotor being mounted on the first step surface through a heat-fitting method, a stator seat being fixed to the rear end of the shell, and a stator being mounted in the stator seat.

[0010] This electric spindle for deep hole grinding has a core shaft installed in its housing through multiple sets of bearings to facilitate the rotation of the core shaft. The stator and rotor are end-face structures, so the heat generated by the spindle motor will not be transferred to the core shaft, ensuring the normal operation of the electric spindle.

[0011] Furthermore, the front end of the core shaft is a second step surface, and the middle part is a third step surface, and the third step surface is higher than the first step surface and the second step surface.

[0012] The third step surface is higher and is used to distinguish the first step surface from the second step surface.

[0013] Furthermore, the end of the core shaft fixes the front end cover to the housing through a front locking nut, and the protrusion on the inner side of the front end cover presses against the outer ring of an outer bearing of the bearing group.

[0014] The locking nut locks the front cover to complete the fixed locking of the front end of the electric spindle and also serves the purpose of dust prevention.

[0015] Furthermore, the inner side of the shell has a limiting step surface of the same length as the second step surface, and the inner washer and the outer washer respectively contact the inner ring and the outer ring of the outer bearing of the second bearing group, and fit on the core shaft and the raised structure of the shell. There are inner spacers fitting on the core shaft and outer spacers fitting on the inner wall of the shell in the first and second bearing groups.

[0016] The inner washer and the outer washer facilitate positioning the installation position of the core shaft and ensure the installation progress of the core shaft. The inner spacer and the outer spacer separate the bearing group one and the bearing group two, which increases the span between the bearing groups and increases the rigidity of the bearing.

[0017] Furthermore, the middle and rear section of the housing has an installation groove for installing the bearing group three, and the outer side of the bearing group three is locked and limited by a locking nut at the rear end of the bearing group three.

[0018] The locking nut locks the position of the bearing group 3, completing the fixation inside the rear end of the core shaft.

[0019] Furthermore, a cooling jacket is mounted on the stator seat by means of interference fit.

[0020] The cooling jacket assists in dissipating heat from the motor stator.

[0021] Furthermore, a rear end cover is threadedly mounted on the tail end of the stator seat.

[0022] The rear end cover serves the purpose of preventing dust and water.

[0023] Through the above scheme, the present invention has at least the following advantages: this electric spindle for deep hole grinding solves the problems of low rotation speed and low grinding efficiency of mechanical shafts for grinding small diameter deep holes. The electric spindle adopts a multi-row arrangement of precision angular contact bearings, and the spindle has high rotation accuracy and high rigidity.

[0024] The motor's stator and rotor are integrated, eliminating the need for intermediate transmission links like belts and gears, enabling high speeds. Compared to mechanical spindles, electric spindles offer high power and torque, high speeds, and high grinding efficiency for mass-produced parts, resulting in high surface quality. Electric spindles are easy to install and remove from the grinding machine. Compared to traditional grinding electric spindles, this design utilizes an end-face configuration for the motor, effectively preventing heat transfer from the motor to the bearing support shaft system. This results in more stable spindle operation, higher precision, and a longer service life.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and to implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate a certain embodiment of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 It is a structural diagram of the utility model;

[0028] Figure 2 This utility model Figure 1 sectional view of

[0029] In the figure, 1 is the housing, 2 is the bearing group 1, 3 is the bearing group 2, 4 is the bearing group 3, 5 is the core shaft, 6 is the extension rod, 7 is the first step surface, 8 is the rotor, 9 is the stator seat, 10 is the stator, 11 is the second step surface, 12 is the third step surface, 13 is the front locking nut, 14 is the front end cover, 15 is the inner washer, 16 is the outer washer, 17 is the inner spacer, 18 is the outer spacer, 19 is the locking nut, 20 is the rear end cover, and 21 is the cooling jacket. DETAILED DESCRIPTION

[0030] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0031] See also Figure 1 and Figure 2This electric spindle for deep hole grinding has a hollow shell 1. The core shaft 5 is installed inside the shell 1 with bearing group 1 2, bearing group 2 3 and bearing group 3 4 from front to back, so that the core shaft 5 can rotate. There is a rotor 8 on the first step surface 7 at the tail end of the core shaft 5. The rotor 8 cooperates with the stator 10 at the tail end of the shell 1. The motor structure with end-face configuration is convenient for installation and can ensure heat dissipation efficiency, avoiding the heat generated by the motor from being conducted to the bearing support shaft system, and the spindle has good thermal stability.

[0032] The extension rod 6 is a detachable structure, which is easy to disassemble and install to meet the processing requirements of different deep holes.

[0033] The middle portion of the core shaft 5 is a raised third step surface 12, which makes the core shaft 5 present a structural form with a high middle portion and low ends, which is convenient for assembling the bearing assembly.

[0034] The front end of the core shaft 5 is fixed to the housing 1 by the front end cover 14 through the front locking nut 13, and the raised structure on the inner side of the front end cover 14 is pressed against the outer ring of the outer bearing of the bearing group 2, completing the limit fixation of the front end of the bearing group 2, and can also provide dust and water proofing compared to pinching the front end cover 14.

[0035] The stepped structure on the inner side of the shell 1 is of the same length as the raised structure at the tail end of the second step surface 11. The inner washer 15 and the outer washer 16 are respectively attached to the core shaft 5 and the inner wall of the shell 1, and are in contact with the inner and outer rings of the bearings on the outside of the bearing group 2 3, so as to position the rear end of the bearing group 2 3. The inner washer 15 and the outer washer 16 are placed at the innermost end of the core shaft 5 to facilitate the adjustment of the spindle accuracy.

[0036] There is a mounting groove on the housing 1 for mounting the bearing group 3 4, which is used to position the bearing group 3 4. The locking nut 19 is screwed into the core shaft 5 to complete the locking and positioning of the bearing group 3 4, and cooperates with the front locking nut 13 at the front end to complete the purpose of locking and positioning the core shaft 5 front and back.

[0037] The cooling jacket 21 installed on the stator seat 9 can assist in heat dissipation of the stator.

[0038] The rear end cover 20 installed at the rear end of the stator seat 9 seals the rear end of the main shaft to prevent external moisture, dust and other debris from entering the bearing, thereby increasing the life of the main shaft.

[0039] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense, and may refer to mechanical or electrical connections, internal communication between two components, or direct connection. "Up," "down," "left," and "right" are only used to indicate relative positional relationships. When the absolute positions of the objects being described change, the relative positional relationships may also change.

[0040] Secondly: The drawings of the embodiments disclosed in this utility model only involve structures related to the embodiments disclosed in this utility model. Other structures can refer to common designs. In the absence of conflicts, the same embodiment and different embodiments of the utility model can be combined with each other.

[0041] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. An electric spindle for deep hole grinding, comprising a housing (1), characterized in that: A core shaft (5) is movably mounted in the cavity of the housing (1) via a first bearing group (2), a second bearing group (3) and a third bearing group (4); an extension rod (6) is mounted on the front end of the core shaft (5) via a threaded screw hole; a first step surface (7) is provided at the rear end of the core shaft (5); a rotor (8) is mounted on the first step surface (7) via a heat-fitting method; a stator seat (9) is fixed to the rear end of the housing (1); and a stator (10) is mounted in the stator seat (9).

2. The electric spindle for deep hole grinding according to claim 1, characterized in that: The front end of the core shaft (5) is a second step surface (11), and the middle part is a third step surface (12). The third step surface (12) is higher than the first step surface (7) and the second step surface (11).

3. The electric spindle for deep hole grinding according to claim 2, characterized in that: The end of the core shaft (5) fixes the front end cover (14) on the housing (1) through the front locking nut (13), and the protrusion on the inner side of the front end cover (14) presses on the outer ring of the outer bearing of the bearing group (2).

4. The electric spindle for deep hole grinding according to claim 3, characterized in that: The inner side of the housing (1) has a limiting step surface of the same length as the second step surface (11); the inner washer (15) and the outer washer (16) are in contact with the inner ring and the outer ring of the outer bearing of the second bearing group (3), respectively, and are fitted on the core shaft (5) and the raised structure of the housing (1); the bearing group (2) and the bearing group (3) have an inner spacer (17) fitted on the core shaft and an outer spacer (18) fitted on the inner wall of the housing (1).

5. The electric spindle for deep hole grinding according to claim 4, characterized in that: The middle and rear section of the housing (1) is provided with a mounting groove for mounting the bearing group three (4), and the outer side of the bearing group three (4) is locked and limited by a locking nut (19) at the rear end of the bearing group three (4).

6. The electric spindle for deep hole grinding according to claim 5, characterized in that: A cooling sleeve (21) is mounted on the stator seat (9) in an interference fit manner.

7. The electric spindle for deep hole grinding according to claim 6, characterized in that: The tail end of the stator seat (9) is threadedly mounted with a rear end cover (20).

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