Main shaft cooling structure and machine tool

Abstract

The invention discloses a spindle cooling structure and a machine tool, and belongs to the technical field of spindles, the spindle cooling structure comprises a machine body, a front bearing seat and a rear bearing seat which are arranged in the machine body, bearings installed in the front bearing seat and the rear bearing seat, and a motor iron core and a motor coil which are arranged in a shell, the cooling water channel comprises a plurality of mutually independent cooling chambers, and the plurality of cooling chambers are respectively and correspondingly arranged at a bearing of the main shaft, a motor iron core and a motor coil; the cooling chambers are sequentially communicated in series through pipeline holes to form a continuous circulating cooling path, so that cooling liquid can sequentially flow through the cooling chambers corresponding to the front bearing, the motor front coil, the motor rear coil, the rear bearing and the motor iron core; according to the invention, the motor coil, which is a core heat source, is incorporated into a direct liquid cooling circulation system, so that the effective heat exchange area is greatly expanded, each heating part of the main shaft can be directly and fully cooled, and the overall heat dissipation efficiency is qualitatively improved.

Description

Technical Field

[0001] This invention relates to the field of spindle technology, and particularly to spindle cooling structures and machine tools. Background Technology

[0002] As a core functional component of modern CNC machine tools, the electric spindle integrates the spindle and motor, possessing advantages such as compact structure, high power density, and fast dynamic response. Its performance directly determines the machining accuracy, efficiency, and reliability of the machine tool. During high-speed, high-load machining processes, a large amount of heat is generated inside the electric spindle, mainly from electromagnetic losses in the motor core and coils, and frictional heat generated by the front and rear support bearings. If the heat cannot be dissipated effectively and in a timely manner, the overall temperature of the spindle will rise, resulting in thermal deformation, specifically manifested as axial thermal elongation and radial thermal drift.

[0003] In existing technologies, common electric spindle cooling solutions mainly focus on setting up cooling water channels in the bearing housing and motor core. These solutions typically involve creating simple annular water tanks or channels within the machine body or bearing housing, allowing coolant to flow through these areas to remove heat. However, such traditional designs have significant limitations: First, the cooling range is incomplete, especially lacking direct and effective cooling measures for the extremely hot motor stator coils. The heat generated by the coils can only be dissipated indirectly through heat conduction, resulting in low efficiency and causing the coil area to become a high-temperature hotspot. Second, the cooling channel design is often rather crude, with potential cross-flow or short-circuiting between different cooling areas, leading to uneven coolant distribution and an inability to achieve differentiated, on-demand cooling for different heat-generating components. Finally, the cooling path lacks systematic planning, failing to optimize the cooling sequence based on the thermal characteristics of each heat source (heat generation, heat capacity, and impact on accuracy).

[0004] The aforementioned defects collectively lead to poor thermal performance of the spindle: bearings experience accelerated grease failure due to excessively high operating temperatures, resulting in increased wear and shortened lifespan; the overall thermal equilibrium temperature of the spindle is high, and thermal deformation is large and unstable, easily causing quality defects such as "uneven machined surfaces" and "tool marks" in precision machining, severely limiting the machining accuracy limits of high-end machine tools. Therefore, developing a novel structure capable of efficiently, uniformly, and controllably cooling all critical heat sources of the electric spindle has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a spindle cooling structure, which aims to solve the problem of heat damage caused by poor spindle cooling and various problems in machining.

[0006] To achieve the aforementioned objectives, the first aspect of this invention proposes a spindle cooling structure, comprising a body, a front bearing housing and a rear bearing housing disposed within the body, two bearings installed within the front and rear bearing housings, and a motor core and a motor coil disposed within a housing. The body is provided with a cooling water channel, which has a coolant inlet and an outlet for circulating cooling of at least a portion of the heat-generating components of the spindle. The cooling water channel includes multiple independent cooling chambers, which are respectively disposed at the bearings, motor core, and motor coil of the spindle. The cooling chambers are connected in series through pipe holes to form a continuous circulating cooling path, so that the coolant can flow sequentially through the cooling chambers corresponding to the front bearing, the front coil of the motor, the rear coil of the motor, the rear bearing, and the motor core. The plurality of cooling chambers include at least a front bearing cooling chamber, a rear bearing cooling chamber, a motor core cooling chamber, a front coil cooling chamber, and a rear coil cooling chamber. The front bearing cooling chamber is formed by the front bearing housing and a cooling water jacket. The front coil cooling chamber and the rear coil cooling chamber of the motor are respectively formed by the cooling water jacket and the machine body; The rear bearing cooling chamber is formed by the rear bearing housing outer sleeve and the rear bearing housing; The motor core cooling chamber is formed by the inner wall of the machine body and the cooling water jacket.

[0007] Optionally, adjacent cooling chambers are isolated from each other by O-rings.

[0008] Optionally, in the circulating cooling path, the coolant flows in the following order: from the front bearing cooling chamber, through the front coil cooling chamber of the motor, the rear coil cooling chamber of the motor, the rear bearing cooling chamber, and finally to the motor core cooling chamber.

[0009] Optionally, the cooling water jacket is a cylindrical structure sleeved on the outside of the motor core and coil, which, together with the motor body and the front bearing housing, defines the cooling chamber of the motor front coil.

[0010] Optionally, the rear bearing housing sleeve and the rear bearing housing are connected as an integral structure by embedding or welding.

[0011] Optionally, the structure of the front coil cooling chamber and / or the rear coil cooling chamber of the motor is configured such that the corresponding part of the cooling water jacket is integrated with the front bearing housing or the machine body to jointly form the cooling chamber.

[0012] Optionally, in the circulating cooling path, the flow sequence of the coolant is any one of the following: first flowing through the motor core cooling chamber, the front coil cooling chamber of the motor, the rear coil cooling chamber of the motor, the front bearing cooling chamber, and then to the rear bearing cooling chamber; Alternatively, the coolant flows first through the front bearing cooling chamber, the front coil cooling chamber of the motor, the core cooling chamber of the motor, and the rear coil cooling chamber of the motor, before reaching the rear bearing cooling chamber.

[0013] Optionally, the coolant inlet is located on the rear bearing housing outer sleeve, and the coolant outlet is located on the rear bearing housing outer sleeve.

[0014] Optionally, the front coil cooling chamber of the motor and the front bearing cooling chamber, the rear coil cooling chamber of the motor and the front coil cooling chamber of the motor, the rear bearing cooling chamber and the rear coil cooling chamber of the motor, and the rear bearing cooling chamber and the motor core cooling chamber are all connected by pipe holes.

[0015] A second aspect of the present invention provides a machine tool including the aforementioned spindle cooling structure.

[0016] The beneficial effects of this invention are: 1. The spindle cooling structure of this invention incorporates the core heat source—the motor coil—into a direct liquid cooling circulation system by setting up multiple independent cooling chambers corresponding to the front bearing, rear bearing, motor core, front-end coil, and rear-end coil of the motor. This significantly expands the effective heat exchange area, fundamentally solving the bottleneck problem of insufficient cooling in the coil area in traditional solutions. This allows all heat-generating parts of the spindle to receive direct and sufficient cooling, resulting in a qualitative improvement in overall heat dissipation efficiency.

[0017] 2. The spindle cooling structure of this invention uses O-rings to seal and isolate adjacent cooling chambers. This design effectively prevents unintended cross-flow of coolant between chambers, ensuring that the preset coolant flow rate flows entirely through the target area. Each cooling chamber becomes a controllable independent heat exchange unit, thereby ensuring the stability and uniformity of the cooling effect and avoiding localized overheating caused by uneven flow distribution.

[0018] 3. The spindle cooling structure of this invention adopts a series path design, implementing a flow sequence of "front bearing → motor coil → rear bearing → motor core," reflecting a strategic thermal management logic. Prioritizing the cooling of the front bearing, which is most sensitive to the precision of the spindle's front end, quickly stabilizes its operating temperature and minimizes spindle thermal expansion. Subsequently, the high-heat-generating coils are cooled, preventing heat transfer to adjacent components. This sequential cooling effectively utilizes the temperature gradient of the coolant, achieving optimal cooling efficiency and thus keeping the overall thermal deformation of the spindle at an extremely low level.

[0019] 4. The spindle cooling structure of this invention, through the disclosed cooling chamber configuration (such as the integrated design of the cooling water jacket and bearing housing) and multiple optional schemes for the coolant flow sequence, provides flexible design space for spindles with different power, speed, and application scenarios (such as engraving and milling machines, grinding machines, and lathes). Designers can adjust the cooling strategy according to the main heat source distribution and precision control focus, making this technology widely applicable and highly viable. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the spindle cooling structure and the cooling water channel structure of the machine tool according to the present invention; Figure 2 This is a top view of the spindle cooling structure and machine tool of the present invention; Figure 3 This is a schematic diagram of the spindle cooling structure and coolant circulation of the machine tool according to the present invention; Figure 4 This is a schematic diagram of the spindle cooling structure and the overall distribution of the cooling chamber of the machine tool according to the present invention; Figure 5 This is a schematic diagram of the connection structure between the spindle cooling structure of the present invention and the front coil cooling chamber of the motor and the front bearing cooling chamber of the machine tool; Figure 6 This is a schematic diagram of the connection structure between the spindle cooling structure of the present invention and the motor rear coil cooling chamber and the motor front coil cooling chamber of the machine tool. Figure 7 This is a schematic diagram of the connection structure between the spindle cooling structure of the present invention and the rear bearing cooling chamber of the machine tool and the rear coil cooling chamber of the motor. Figure 8 This is a schematic diagram of the connection structure between the spindle cooling structure of the present invention and the rear bearing cooling chamber and the motor core cooling chamber of the machine tool.

[0021] Explanation of reference numerals in the attached figures: 1. Rear bearing housing outer sleeve; 2. Rear bearing housing; 3. Machine body; 4. Motor; 5. Cooling water jacket; 6. Front bearing housing; 7. O-ring; 8. Bearing; 9. Rear bearing cooling chamber; 10. Motor rear coil cooling chamber; 11. Motor core cooling chamber; 12. Motor front coil cooling chamber; 13. Front bearing cooling chamber.

[0022] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0024] In the description of this invention, 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, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] Example 1 Reference Figures 1-8 An embodiment of the present invention provides a spindle cooling structure, including a body 3, a front bearing seat 6 and a rear bearing seat 2 disposed within the body 3, two bearings 8 installed within the front bearing seat 6 and the rear bearing seat 2, and a motor core and a motor coil disposed within a housing. The body 3 is provided with a cooling water channel, which has a coolant inlet and an outlet for circulating cooling of at least some of the heat-generating components of the spindle. The cooling water channel includes multiple independent cooling chambers, which are respectively disposed at the bearings 8, the motor core, and the motor coil of the spindle. The cooling chambers are connected in series via pipe holes, forming a continuous circulating cooling path, allowing the coolant to flow sequentially through the cooling chambers corresponding to the front bearing, the front coil of the motor, the rear coil of the motor, the rear bearing, and the motor core. The bearing 8 includes both a front bearing and a rear bearing.

[0026] It should be noted that, as Figure 1 , Figure 3 As shown, the spindle cooling structure of this invention mainly includes a body 3, a front bearing housing 6, a rear bearing housing 2, a cooling water jacket 5, a rear bearing housing outer sleeve 1, and necessary seals such as O-rings 7. The motor core and coil (not shown in the figure) are installed inside the body 3. Coolant (e.g., water or oil-based coolant) is pumped in from an external cooling system, flows through the continuous cooling water channels formed inside this structure, and then flows out, carrying away heat.

[0027] The coolant enters the system through the coolant inlet located on the rear bearing housing outer sleeve 1, and flows sequentially through the following five mutually isolated cooling chambers connected in series via pipe holes: The front bearing cooling chamber 13 provides priority cooling for the front bearing.

[0028] The front coil cooling chamber 12 of the motor cools the motor coil section near the front bearing side.

[0029] The motor rear coil cooling chamber 10 cools the motor coil section near the rear bearing side.

[0030] The rear bearing cooling chamber 9 cools the rear bearing.

[0031] The motor core is cooled in the cooling chamber 11.

[0032] After cooling the motor core, the coolant flows back through the pipe holes inside the housing 3 to the coolant outlet on the rear bearing housing outer sleeve 1, completing a full cycle. This path ensures that the coolant can exchange heat with each of the main heat sources in sequence and sufficiently.

[0033] The cooling water channel is composed of multiple independent cooling chambers connected in series, forming a continuous cooling network covering all key heat-generating components. The advantage of this structure is that it breaks down the overall cooling task into targeted cooling of local heat sources, avoiding the cooling dead zones and uneven flow distribution problems that may occur with traditional single-chamber cooling systems. The series design ensures that the coolant at a given flow rate can flow sequentially through all predetermined parts, achieving effective utilization of cooling resources and systematized thermal management, thus improving the uniformity and reliability of cooling overall. There are connecting pipe holes between the motor front coil cooling chamber 12 and the front bearing cooling chamber 13, between the motor rear coil cooling chamber 10 and the motor front coil cooling chamber 12, between the rear bearing cooling chamber 9 and the motor rear coil cooling chamber 10, and between the rear bearing cooling chamber 9 and the motor core cooling chamber 11.

[0034] In some embodiments, the plurality of cooling chambers includes at least a front bearing cooling chamber 13, a rear bearing cooling chamber 9, a motor core cooling chamber 11, a front motor coil cooling chamber 12, and a rear motor coil cooling chamber 10. The front bearing cooling chamber 13 is formed by a front bearing housing 6 and a cooling water jacket 5. The front coil cooling chamber 12 and the rear coil cooling chamber 10 of the motor are respectively enclosed by the cooling water jacket 5 and the body 3; The rear bearing cooling chamber 9 is formed by the rear bearing housing outer sleeve 1 and the rear bearing housing 2; The motor core cooling chamber 11 is formed by the inner wall of the machine body 3 and the cooling water jacket 5.

[0035] It should be noted that the plurality of cooling chambers specifically includes a front bearing cooling chamber 13, a rear bearing cooling chamber 9, a motor core cooling chamber 11, a front motor coil cooling chamber 12, and a rear motor coil cooling chamber 10. These are formed in the following manner: The front bearing cooling chamber 13 is formed by the front bearing housing 6 and the front end of the cooling water jacket 5 sleeved on the outside of the motor. This enclosed structure directly forms a cooling cavity around the bearing housing, allowing the coolant to flow closely to the outer ring of the bearing 8.

[0036] The front coil cooling chamber 12 and the rear coil cooling chamber 10 of the motor are mainly formed by the annular space between the outer wall of the cooling water jacket 5 and the inner wall of the body 3. The cooling water jacket 5 acts as an isolator, separating the coil area from other parts of the body, thereby forming a dedicated cooling cavity surrounding the coil.

[0037] The rear bearing cooling chamber 9 is formed by the annular gap between the rear bearing housing outer sleeve 1 and the rear bearing housing 2 installed inside it.

[0038] The motor core cooling chamber 11 is formed by the inner wall of the body 3 and the outer wall of the cooling water jacket 5 in a region corresponding to the length of the motor core. The cooling water jacket 5 also serves as a key component in forming the cooling flow channel.

[0039] By making full use of existing mechanical structures (such as bearing housings and body 3) and introducing special components (cooling water jackets), the most direct enveloping cooling of each heat-generating part is achieved with minimal space modification, greatly increasing the effective heat exchange area between the coolant and the heat source.

[0040] In some embodiments, adjacent cooling chambers are isolated from each other by O-rings 7.

[0041] It should be noted that O-rings 7 are installed at the joint surfaces between adjacent cooling chambers for sealing and isolation, ensuring the independence of each cooling chamber and preventing coolant short-circuiting or cross-flow. This ensures the strict execution of the preset cooling path, allowing each cooling chamber to obtain the coolant flow rate and velocity required by the design.

[0042] In some embodiments, in the circulating cooling path, the flow sequence of the coolant is as follows: from the front bearing cooling chamber 13, it flows sequentially through the front coil cooling chamber 12 of the motor, the rear coil cooling chamber 10 of the motor, the rear bearing cooling chamber 9, and finally to the motor core cooling chamber 11.

[0043] It should be noted that in the circulation path, the coolant is designed to flow in the following order: front bearing → front motor coil → rear motor coil → rear bearing → motor core. This achieves strategic cooling priority. First, the front bearing, which bears the heaviest load and has the greatest impact on the accuracy of the spindle front end, is cooled, quickly stabilizing its operating temperature and minimizing spindle thermal expansion. Next, the rapidly generating motor coils are cooled, preventing heat transfer to the bearings and core. After the coolant temperature has risen somewhat, cooling the relatively smaller, floating rear bearing has a limited impact on its performance. Finally, the motor core, with its large heat capacity, is cooled, as the coolant, having passed through all heat sources, can still effectively remove its accumulated heat. This optimization of the coolant temperature rise curve maximizes cooling efficiency.

[0044] In some embodiments, the cooling water jacket 5 is a cylindrical structure sleeved on the outside of the motor core and coil, which, together with the body 3 and the front bearing seat 6, defines the front coil cooling chamber 12 of the motor.

[0045] It should be noted that the cooling water jacket 5 is a cylindrical structure fitted onto the outside of the motor stator (including the iron core and coils). As a core functional component, this water jacket integrally forms the boundaries of the front-end coil cooling chamber 12, the motor iron core cooling chamber 11, and the rear-end coil cooling chamber 10 (or part thereof). This design simplifies the machining of the internal flow channels of the body 3, transforming the complex cooling cavity into a space assembled from a prefabricated component and the body 3, improving the manufacturability and reliability of the structure, and ensuring the integrity of cooling in the coil and iron core areas.

[0046] In some embodiments, the rear bearing housing outer sleeve 1 and the rear bearing housing 2 are connected as an integral structure by embedding or welding.

[0047] It should be noted that the rear bearing housing outer sleeve 1 and the rear bearing housing 2 can be connected as a single unit through interference fit or welding. Integrating the two parts eliminates the risk of leakage at their mating surfaces and enhances the structural rigidity and sealing reliability of the rear bearing cooling chamber 9. The integrated design also reduces assembly steps and improves the overall integrity and stability of the components.

[0048] In some embodiments, the structure of the front coil cooling chamber 12 and / or the rear coil cooling chamber 10 of the motor is configured such that the corresponding portion of the cooling water jacket 5 is integrated with the front bearing housing 6 or the body 3 to jointly form the cooling chamber.

[0049] As another implementation, a corresponding portion (e.g., the end) of the cooling water jacket 5 is structurally integrated with the front bearing housing 6 or the body 3 to form a cooling chamber (e.g., designed as a single part or connected in a non-removable manner). This further reduces the number of parts and assembly interfaces, simplifies sealing requirements or optimizes the cooling channel shape in specific areas under certain designs, and provides flexibility for spindle designs of different models and with space constraints.

[0050] In some embodiments, the flow sequence of the coolant in the circulating cooling path is any of the following: first flowing through the motor core cooling chamber 11, the front coil cooling chamber 12, the rear coil cooling chamber 10, the front bearing cooling chamber 13, and then to the rear bearing cooling chamber 9. Alternatively, the coolant flows first through the front bearing cooling chamber 13, the front coil cooling chamber 12, the core cooling chamber 11, and the rear coil cooling chamber 10, before reaching the rear bearing cooling chamber 9.

[0051] It should be noted that the flow sequence of the coolant in the circulating cooling path can be adjusted according to different thermal management strategies. For example, it can be set as follows: first flowing through the motor core cooling chamber 11, the motor front coil cooling chamber 12, the motor rear coil cooling chamber 10, the front bearing cooling chamber 13, and then to the rear bearing cooling chamber 9; or, first flowing through the front bearing cooling chamber 13, the motor front coil cooling chamber 12, the motor core cooling chamber 11, the motor rear coil cooling chamber 10, and then to the rear bearing cooling chamber 9. The advantage of adjustable flow sequence is that it allows this cooling structure to adapt to different working conditions and application requirements. For example, when the motor load is extremely high and becomes the main heat source, a priority cooling sequence for the motor and coils can be adopted; when extreme control of the spindle front precision is required, a scheme that prioritizes the cooling of the front bearing can be strengthened.

[0052] In some embodiments, the coolant inlet is disposed on the rear bearing housing outer sleeve 1, and the coolant outlet is disposed on the rear bearing housing outer sleeve 1.

[0053] It should be noted that both the coolant inlet and outlet are centrally located on the outer sleeve 1 of the rear bearing housing. The advantage of this arrangement is that it integrates the coolant input and output interfaces at the non-drive end (rear end) of the spindle, making the connection of external cooling pipes more centralized and convenient, avoiding multiple openings in the spindle housing, and contributing to the overall sealing design and neat appearance of the spindle.

[0054] In summary, the cooling circulation path in this application is not limited to the preferred order described above. Based on the same series structure of multiple independent cooling chambers, different cooling sequences can be easily achieved by changing the layout of the pipe holes connecting each cooling chamber. For example: Option A: The coolant flows sequentially through the motor core cooling chamber 11 → the front coil cooling chamber 12 → the rear coil cooling chamber 10 → the front bearing cooling chamber 13 → the rear bearing cooling chamber 9. This option prioritizes addressing the overall heat generation of motor 4 and is suitable for continuous high-load operation of motor 4.

[0055] Option B: The coolant flows sequentially through the front bearing cooling chamber 13 → the front coil cooling chamber 12 of the motor → the motor core cooling chamber 11 → the rear coil cooling chamber 10 of the motor → the rear bearing cooling chamber 9. This option prioritizes cooling the front bearing and then immediately cools the adjacent motor section 4, which helps control the temperature rise gradient at the front of the spindle.

[0056] The above examples all remain within the core concept of this invention: using series-connected independent cooling chambers for systematic cooling, and can achieve corresponding cooling benefits based on actual heat distribution characteristics.

[0057] Example 2 This embodiment provides a machine tool including a spindle unit, which employs the aforementioned spindle cooling structure. The machine tool can be a machining center, CNC milling machine, mill-turning machine, grinding machine, or any other type of machine tool requiring a high-precision, high-speed spindle. The spindle cooling structure, as a core thermal management component of the machine tool spindle, is integrated and installed within the machine tool's spindle box or corresponding support structure.

[0058] Thanks to the aforementioned efficient and precise spindle cooling structure, the spindle temperature rise is effectively suppressed and thermal deformation is significantly reduced under high-speed, heavy-load, and long-term operating conditions. This directly translates into higher machining accuracy and stability, better surface finish, and a longer spindle lifespan. Simultaneously, the excellent heat dissipation capacity allows the spindle to operate continuously at higher power and speeds, enhancing the overall machining efficiency and performance potential of the machine tool.

[0059] In practical application, firstly, the supply pipe of the external cooling system is connected to the coolant inlet on the outer sleeve 1 of the rear bearing housing located at the non-drive end of the spindle, and the return pipe is connected to the coolant outlet on the outer sleeve to complete the physical connection of the cooling circuit. The external cooling system is then started, and the coolant is pumped in through the inlet, first entering the starting end of the series circulation cooling path—the front bearing cooling chamber 13 formed by the front bearing housing 6 and the cooling water jacket 5. The coolant circulates within this chamber, directly carrying away the heat generated by the front bearing during operation, achieving priority cooling of the key support parts of the spindle, which is beneficial for controlling the thermal expansion of the spindle front end. Subsequently, the coolant flows through the pipe holes inside the machine body 3 into the motor front coil cooling chamber 12 formed by the cooling water jacket 5 and the inner wall of the machine body 3, cooling the adjacent... The front bearing motor coil section is cooled; then, the coolant continues to flow through the rear coil cooling chamber 10 of the motor, which has the same structure, to complete the overall cooling of the motor coil; thereafter, the coolant, which has increased in temperature, enters the rear bearing cooling chamber 9, which is formed by the rear bearing housing outer sleeve 1 and the rear bearing housing 2, to fully dissipate heat from the relatively low-heat rear bearing; finally, the coolant flows into the motor core cooling chamber 11, which is formed by the inner wall of the body 3 and the cooling water jacket 5 in the axial region of the motor core, to perform the final stage of cooling for the motor core with a large heat capacity; the coolant that has completed all heat exchange finally flows back to the outlet of the rear bearing housing outer sleeve 1 through the pipe of the body 3 and is discharged to the external cooling system for cooling, thus forming a continuously operating closed loop.

[0060] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A spindle cooling structure, comprising a machine body (3), a front bearing seat (6) and a rear bearing seat (2) arranged in the machine body (3), two bearings (8) mounted in the front bearing seat (6) and the rear bearing seat (2), and a motor core and a motor coil arranged in the machine body, the machine body (3) is internally provided with a cooling water channel, the cooling water channel is provided with a cooling liquid inlet and an outlet, and is used for circulating cooling at least part of heat generating components of the spindle, characterized in that: the cooling water channel comprises a plurality of independent cooling chambers, and the plurality of cooling chambers are respectively arranged at positions corresponding to bearings, a motor core and a motor coil of the spindle; the cooling chambers are sequentially and continuously communicated through pipe holes, so as to form a continuous circulating cooling path, so that the cooling liquid can sequentially flow through the cooling chambers corresponding to the front bearing, the motor front coil, the motor rear coil, the rear bearing and the motor core; the plurality of cooling chambers at least comprise a front bearing cooling chamber (13), a rear bearing cooling chamber (9), a motor core position cooling chamber (11), a motor front end coil cooling chamber (12) and a motor rear end coil cooling chamber (10); the front bearing cooling chamber (13) is formed by the front bearing seat (6) and a cooling jacket (5); the motor front end coil cooling chamber (12) and the motor rear end coil cooling chamber (10) are respectively formed by the cooling jacket (5) and the machine body (3); the rear bearing cooling chamber (9) is formed by a rear bearing seat outer sleeve (1) and the rear bearing seat (2); and the motor core position cooling chamber (11) is formed by the inner wall of the machine body (3) and the cooling jacket (5); adjacent cooling chambers are isolated from each other by O-rings (7); in the circulating cooling path, the flow sequence of the cooling liquid is from the front bearing cooling chamber (13), sequentially through the motor front end coil cooling chamber (12), the motor rear end coil cooling chamber (10), the rear bearing cooling chamber (9), and finally to the motor core position cooling chamber (11); the cooling jacket (5) is a cylindrical structure sleeved outside the motor core and the coil, and the cooling jacket (5), the machine body (3) and the front bearing seat (6) jointly define the motor front end coil cooling chamber (12); the rear bearing seat outer sleeve (1) and the rear bearing seat (2) are connected in an integrated structure by embedding or welding; the structure of the motor front end coil cooling chamber (12) and / or the motor rear end coil cooling chamber (10) is arranged such that the corresponding part of the cooling jacket (5) is integrated with the front bearing seat (6) or the machine body (3) to jointly form the cooling chamber; in the circulating cooling path, the flow sequence of the cooling liquid is any one of the following: first through the motor core position cooling chamber (11), the motor front end coil cooling chamber (12), the motor rear end coil cooling chamber (10), the front bearing cooling chamber (13), and then to the rear bearing cooling chamber (9); or first through the front bearing cooling chamber (13), the motor front end coil cooling chamber (12), the motor core position cooling chamber (11), the motor rear end coil cooling chamber (10), and then to the rear bearing cooling chamber (9). ​ ​ ​ ​ ​ ​ ​ 2. The main shaft cooling structure according to claim 1, characterized by ​ 3. The main shaft cooling structure according to claim 1, characterized by ​ 4. The main shaft cooling structure according to claim 1, characterized by ​ 5. The main shaft cooling structure according to claim 1, characterized by ​ 6. The main shaft cooling structure according to claim 1, characterized by ​ 7. The main shaft cooling structure according to claim 1, characterized by ​ ​ 8. The main shaft cooling structure according to claim 1, characterized by The cooling liquid inlet is arranged on the rear bearing seat outer sleeve (1), and the cooling liquid outlet is arranged on the rear bearing seat outer sleeve (1).

9. The main shaft cooling structure according to claim 1, characterized by The motor front end coil cooling chamber (12) and the front bearing cooling chamber (13), the motor rear end coil cooling chamber (10) and the motor front end coil cooling chamber (12), the rear bearing cooling chamber (9) and the motor rear end coil cooling chamber (10), and the rear bearing cooling chamber (9) and the motor iron core position cooling chamber (11) are all provided with communicating pipeline holes.

10. A machine tool, characterized by A spindle cooling structure comprising any one of claims 1 to 9.

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