Electric spindle for numerically controlled machine tools

Abstract

The utility model relates to electric main shaft technical field, concretely is a kind of electric main shaft for numerical control machine tool, including shell, the inside of shell is provided with first bearing, stator coil and second bearing, the middle part rotationally connected with main shaft body in shell inside, be provided with rotor and encoder wheel on main shaft body, and the one end of main shaft body is provided with tool knock cylinder;Cooling medium inlet and cooling medium outlet are provided on shell, first annular groove and second annular groove are set up on shell, dispersion groove and cooling groove are set up on shell, heat conduction sheet is fixedly connected in cooling groove, dispersion hole is set up between dispersion groove and cooling groove.Effect is beneficial in that: when cooling medium enters into cooling groove from dispersion groove, it can be evenly dispersed into, to ensure the uniformity of main shaft body cooling cooling, avoid the temperature gradient to be generated on the different parts of main shaft body, to avoid the irregular thermal deformation of main shaft body due to temperature difference, ensure the precision of processing.

Description

Technical Field

[0001] This utility model relates to the field of electric spindle technology, and in particular to an electric spindle for CNC machine tools. Background Technology

[0002] With the rapid development and increasing sophistication of electric drive technology, the mechanical structure of the main drive system of high-speed CNC machine tools has been greatly simplified, essentially eliminating belt drives and gear drives. The machine tool spindle is directly driven by an internal electric motor, thereby shortening the length of the main drive chain to zero and achieving "zero transmission" for the machine tool.

[0003] Because electric spindles integrate the motor into the spindle unit and operate at high speeds, they generate a large amount of heat during operation, causing a temperature rise and deteriorating their thermal and dynamic characteristics, thus affecting normal operation. Therefore, measures must be taken to control the temperature of the electric spindle and keep it constant within a certain range. Machine tools generally use forced circulation oil cooling to cool the stator and spindle bearings of the electric spindle. This involves forcibly circulating cooling oil outside the spindle stator and spindle bearings to remove the heat generated by the high-speed rotation of the spindle.

[0004] The electric spindle of a machine tool disclosed in Chinese Patent CN222058841U not only cools the spindle body to extend its service life, but also facilitates its assembly and manufacturing. However, compared with existing technologies and comparative solutions, this electric spindle still has the following problems in actual use:

[0005] When cooling the spindle body, the part of the spindle body near the cooling medium inlet receives different cooling effects than other parts of the spindle body, affecting the overall cooling uniformity of the spindle body. The temperature is lower near the cooling medium inlet and higher further away, creating a temperature gradient in different parts of the spindle body. Since the metal spindle body expands when heated, the temperature difference causes irregular thermal deformation of the spindle body, which affects the machining accuracy. Utility Model Content

[0006] The purpose of this utility model is to overcome the shortcomings of the prior art, solve the problems mentioned in the background art, and provide an electric spindle for CNC machine tools.

[0007] The purpose of this utility model is achieved through the following technical solution: an electric spindle for CNC machine tools, including a housing, a first bearing, a stator coil and a second bearing are arranged inside the housing, a spindle body is rotatably connected to the middle of the housing, a rotor and an encoder wheel are arranged on the spindle body, and a tool-changing cylinder is arranged at one end of the spindle body;

[0008] The outer casing is provided with a cooling medium inlet and a cooling medium outlet. The outer casing has a first annular groove and a second annular groove. The outer casing also has a dispersion groove and a cooling groove. A heat-conducting plate is fixedly connected inside the cooling groove. Dispersion holes are provided between the dispersion groove and the cooling groove. There are multiple sets of dispersion holes, and multiple sets of dispersion holes are distributed in a circumferential array between the dispersion groove and the cooling groove. Each set of dispersion holes has multiple holes. The multiple dispersion holes in each set are linearly distributed between the dispersion groove and the cooling groove. The dispersion holes closer to the first annular groove have smaller diameters, and the dispersion holes farther from the first annular groove have larger diameters. An annular connecting groove is provided between the dispersion groove and the cooling groove.

[0009] Preferably, the spindle body is rotatably connected inside the housing via a first bearing and a second bearing.

[0010] Preferably, the second annular groove is disposed inside the first annular groove, the cooling medium inlet is connected to the first annular groove, and the cooling medium outlet is connected to the second annular groove.

[0011] Preferably, the cooling tank is disposed inside the dispersion tank, and a first connecting hole is provided between the dispersion tank and the first annular tank. The number of first connecting holes is multiple and they are distributed in a circumferential array between the dispersion tank and the first annular tank. A second connecting hole is provided between the cooling tank and the second annular tank. The number of second connecting holes is multiple and they are distributed in a circumferential array between the cooling tank and the second annular tank.

[0012] Preferably, there are multiple heat-conducting plates, which are distributed in a circumferential array inside the cooling tank.

[0013] Preferably, the annular connecting groove is located on the side of the dispersing groove away from the first annular groove.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The electric spindle of this CNC machine tool can evenly disperse the cooling medium as it enters the cooling tank from the dispersion tank, thereby ensuring the uniformity of cooling of the spindle body and avoiding temperature gradients in different parts of the spindle body. This prevents irregular thermal deformation of the spindle body due to temperature differences and ensures machining accuracy.

[0016] The parts of the device not covered herein are the same as or can be implemented using existing technologies. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of 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 some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a partial cross-sectional view of the present invention.

[0020] Figure 3 This is a cross-sectional structural diagram of the present invention;

[0021] Figure 4 This utility model Figure 3 Enlarged structural diagram at point A;

[0022] Figure 5 This utility model Figure 3 Enlarged structural diagram at point B;

[0023] Figure 6 This utility model Figure 3 A magnified schematic diagram of the structure at point C.

[0024] In the diagram: 1. Outer shell; 101. Cooling medium inlet; 102. Cooling medium outlet; 103. First annular groove; 104. Second annular groove; 105. Dispersion groove; 106. Cooling groove; 107. Heat-conducting plate; 108. Dispersion hole; 109. Annular connecting groove; 2. First bearing; 3. Stator coil; 4. Rotor; 5. Main shaft body; 6. Second bearing; 7. Encoding wheel; 8. Tool-changing cylinder. Detailed Implementation

[0025] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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.

[0026] Additional aspects and advantages of this invention will be further set forth in the description which follows in conjunction with the accompanying drawings, and in part will be obvious from the description or may be learned by practice of the invention.

[0027] like Figures 1 to 3 As shown, an electric spindle for a CNC machine tool includes a housing 1. Inside the housing 1, a first bearing 2, a stator coil 3, and a second bearing 6 are arranged. The stator coil 3 is fixedly connected inside the housing 1. A spindle body 5 is rotatably connected to the middle of the housing 1. The spindle body 5 is rotatably connected to the housing 1 through the first bearing 2 and the second bearing 6. A rotor 4 and an encoder wheel 7 are arranged on the spindle body 5. An encoder is arranged inside the housing 1 at a position corresponding to the encoder wheel 7. A tool-changing cylinder 8 is arranged at one end of the spindle body 5.

[0028] like Figures 2 to 6 As shown, the outer casing 1 is provided with a cooling medium inlet 101 and a cooling medium outlet 102. A first annular groove 103 and a second annular groove 104 are formed on the outer casing 1. The second annular groove 104 is located inside the first annular groove 103. The cooling medium inlet 101 is connected to the first annular groove 103, and the cooling medium outlet 102 is connected to the second annular groove 104. A dispersion groove 105 and a cooling groove 106 are formed on the outer casing 1. The cooling groove 106 is located inside the dispersion groove 105. A first connecting hole is formed between the dispersion groove 105 and the first annular groove 103. Multiple first connecting holes are arranged in a circumferential array between the dispersion groove 105 and the first annular groove 103. Multiple second connecting holes are also formed between the cooling groove 106 and the second annular groove 104, arranged in a circumferential array between the cooling groove 106 and the second annular groove 104. Between 04, a heat-conducting plate 107 is fixedly connected inside the cooling tank 106. There are multiple heat-conducting plates 107, which are arranged in a circumferential array inside the cooling tank 106. A dispersion hole 108 is provided between the dispersion tank 105 and the cooling tank 106. There are multiple groups of dispersion holes 108, which are arranged in a circumferential array between the dispersion tank 105 and the cooling tank 106. Each group of dispersion holes 108 has multiple holes, and the multiple dispersion holes 108 in each group are arranged in a linear array between the dispersion tank 105 and the cooling tank 106. The dispersion holes 108 closer to the first annular groove 103 have smaller diameters, and the dispersion holes 108 farther from the first annular groove 103 have larger diameters. An annular connecting groove 109 is provided between the dispersion tank 105 and the cooling tank 106. The annular connecting groove 109 is located on the side of the dispersion tank 105 away from the first annular groove 103.

[0029] All electronic components mentioned in this article are electrically connected to an external main controller and 220V AC mains power. The main controller can be a conventional, known device such as a computer. The electronic components, along with their associated control systems, power supply modules, circuits, and piping, can be provided by the manufacturer. Furthermore, all electronic components and control modules involved in this invention are existing technologies, fully capable of being implemented by those skilled in the art, and require no further explanation. This invention does not involve any improvement to the structure or usage of the electronic components.

[0030] The work process is as follows:

[0031] S1. When the spindle body 5 needs to be cooled during use, the cooling medium enters the first annular groove 103 from the cooling medium inlet 101.

[0032] S2. Then, it enters the dispersion groove 105 through the first connecting hole between the first annular groove 103 and the dispersion groove 105;

[0033] S3. Then, the heat generated by the spindle body 5 enters the cooling tank 106 through the dispersion hole 108 and the annular connecting groove 109 between the dispersion groove 105 and the cooling tank 106. The heat generated by the spindle body 5 is transferred to the heat conduction plate 107 through the outer shell 1 and is cooled down by the cooling medium in the cooling tank 106.

[0034] S4. Subsequently, the cooling medium enters the second annular groove 104 through the second connecting hole between the cooling groove 106 and the second annular groove 104, and is finally discharged from the cooling medium outlet 102.

[0035] S5. Since there are multiple sets of dispersion holes 108, the multiple sets of dispersion holes 108 are distributed in a circumferential array between the dispersion groove 105 and the cooling groove 106. Each set of dispersion holes 108 has multiple holes, and the multiple dispersion holes 108 in each set are linearly distributed between the dispersion groove 105 and the cooling groove 106. The dispersion holes 108 closer to the first annular groove 103 have smaller diameters, and the dispersion holes 108 farther from the first annular groove 103 have larger diameters. When the cooling medium enters the cooling groove 106 from the dispersion groove 105, it can be evenly dispersed, thereby ensuring the uniformity of cooling of the spindle body 5, avoiding temperature gradients in different parts of the spindle body 5, and thus avoiding irregular thermal deformation of the spindle body 5 due to temperature differences, ensuring machining accuracy.

[0036] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. An electric spindle for a numerically controlled machine tool, characterized in that: Includes a housing (1), inside which a first bearing (2), a stator coil (3) and a second bearing (6) are provided, and a main shaft body (5) is rotatably connected to the middle of the housing (1). A rotor (4) and an encoder wheel (7) are provided on the main shaft body (5), and a tool-changing cylinder (8) is provided at one end of the main shaft body (5). The outer shell (1) is provided with a cooling medium inlet (101) and a cooling medium outlet (102). A first annular groove (103) and a second annular groove (104) are formed on the outer shell (1). A dispersion groove (105) and a cooling groove (106) are formed on the outer shell (1). A heat-conducting plate (107) is fixedly connected inside the cooling groove (106). A dispersion hole (108) is formed between the dispersion groove (105) and the cooling groove (106). Multiple sets of dispersion holes (108) are arranged in a circumferential array. Between the dispersion groove (105) and the cooling groove (106), there are multiple dispersion holes (108) in a group. The multiple dispersion holes (108) in each group are linearly arrayed between the dispersion groove (105) and the cooling groove (106). The dispersion holes (108) closer to the first annular groove (103) have smaller apertures, and the dispersion holes (108) farther from the first annular groove (103) have larger apertures. An annular connecting groove (109) is provided between the dispersion groove (105) and the cooling groove (106).

2. An electric spindle for a numerically controlled machine tool according to claim 1, characterized in that: The main shaft body (5) is rotatably connected inside the outer casing (1) via the first bearing (2) and the second bearing (6).

3. The electric spindle for a CNC machine tool according to claim 1, characterized in that: The second annular groove (104) is disposed inside the first annular groove (103), the cooling medium inlet (101) is connected to the first annular groove (103), and the cooling medium outlet (102) is connected to the second annular groove (104).

4. The electric spindle for a CNC machine tool according to claim 1, characterized in that: The cooling groove (106) is disposed inside the dispersion groove (105). A first connecting hole is provided between the dispersion groove (105) and the first annular groove (103). The number of the first connecting holes is multiple and they are arranged in a circumferential array between the dispersion groove (105) and the first annular groove (103). A second connecting hole is provided between the cooling groove (106) and the second annular groove (104). The number of the second connecting holes is multiple and they are arranged in a circumferential array between the cooling groove (106) and the second annular groove (104).

5. The electric spindle for a CNC machine tool according to claim 1, characterized in that: The number of heat-conducting plates (107) is multiple, and the multiple heat-conducting plates (107) are arranged in a circumferential array inside the cooling groove (106).

6. The electric spindle for a CNC machine tool according to claim 1, characterized in that: The annular connecting groove (109) is disposed on the side of the dispersing groove (105) away from the first annular groove (103).

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