Machine tool spindle

Abstract

The application discloses a machine tool spindle, which aims at solving the technical problems of heat accumulation in the rear bearing seat when using the "front-middle-rear" cooling scheme and the heat accumulation in the front bearing seat when using the "rear-middle-front" cooling scheme. The cooling liquid channel distributed in the shell layer of the rear bearing seat comprises a rear bearing seat annular cooling channel, the cooling liquid channel distributed in the shell layer of the spindle body comprises a spindle body annular cooling channel and a spindle body axial guide channel, and the cooling liquid channel distributed in the shell layer of the front bearing seat comprises a front bearing seat annular cooling channel. When the spindle cooling system is working, the cooling liquid flows among the rear bearing seat annular cooling channel, the spindle body annular cooling channel and the front bearing seat annular cooling channel in the order of first passing through the rear bearing seat annular cooling channel, then passing through the front bearing seat annular cooling channel and finally passing through the spindle body annular cooling channel.

Description

Technical Field

[0001] This invention relates to a machine tool spindle and a front bearing housing for the machine tool spindle. Background Technology

[0002] In its patent application No. 202211525780.2, the applicant disclosed a machine tool spindle with a spindle cooling system. This system includes a network of coolant channels distributed within the spindle body, the front bearing housing, and the rear bearing housing, connecting to the machine tool coolant inlet and outlet ports, respectively. According to paragraph 0081 of the patent specification, during operation, the coolant first passes through the coolant channels in the front bearing housing, then through the coolant channels in the spindle body (which have multiple axial channels extending along the spindle body's axis), and finally through the coolant channels in the rear bearing housing; that is, the spindle cooling system adopts a "front-middle-rear" cooling scheme.

[0003] Subsequently, the applicant provided a machine tool spindle in patent application number 202311546879.5. To improve the cooling effect on the main heat source of the machine tool spindle during operation, namely the motor stator, the applicant improved the coolant channel in the spindle body. By adding an intermediate sleeve between the inner wall of the spindle body and the outer wall of the motor stator, a coolant flow path covering the outside of the motor stator is formed, which can more effectively cool the motor stator. In addition, according to the description in the patent document, when the spindle cooling system is working, the coolant first passes through the coolant channel in the rear bearing housing, then through the coolant channel in the spindle body, and finally through the coolant channel in the front bearing housing; that is, the spindle cooling system adopts a "rear-middle-front" cooling scheme.

[0004] The inventors discovered that when using the aforementioned "front-middle-rear" cooling scheme, the coolant first passes through the front bearing housing, where the coolant temperature is lowest and the cooling effect is best. However, the main heat source of the machine tool spindle during operation is the motor stator. After the coolant cools the spindle body, its temperature has already risen significantly, resulting in poor cooling effect when cooling the rear bearing housing subsequently, which easily leads to heat accumulation in the rear bearing housing. Conversely, with the aforementioned "rear-middle-front" cooling scheme, the coolant first passes through the rear bearing housing, where the cooling effect is best. After the coolant cools the spindle body, its temperature has already risen significantly, resulting in poor cooling effect when cooling the front bearing housing subsequently, which easily leads to heat accumulation in the front bearing housing. Summary of the Invention

[0005] The purpose of this invention is to provide a machine tool spindle and a front bearing housing for the machine tool spindle, so as to solve the technical problems of heat accumulation in the rear bearing housing when the above-mentioned "front-middle-rear" cooling scheme is adopted and heat accumulation in the front bearing housing when the above-mentioned "rear-middle-front" cooling scheme is adopted.

[0006] In a first aspect, a machine tool spindle is provided, comprising: a spindle body; a spindle motor, the spindle motor including a motor stator and a motor rotor, the motor stator being fixed in the spindle body and the motor rotor being adapted to the motor stator; a spindle core, the spindle core being rotatably mounted in the spindle body via a front bearing system and a rear bearing system and rotating with the motor rotor, the front end of the spindle core being provided with a tool holder assembly structure; a front bearing system, the front bearing system including a front bearing housing and a front bearing, the front bearing housing being disposed at the front end of the spindle body, the front bearing being mounted in the front bearing housing and rotatably supporting the front part of the spindle core; and a rear bearing system, the rear bearing system including a rear bearing housing and a rear bearing, the rear bearing housing being disposed at the rear end of the spindle body, the rear bearing being mounted in the rear bearing housing and rotatably supporting the front part of the spindle core; and a rear bearing system, the rear bearing system including a rear bearing housing and a rear bearing, the rear bearing housing being disposed at the rear end of the spindle body, the rear bearing being mounted in the rear bearing housing. The rear bearing housing is installed and rotatably supports the rear part of the spindle core; a tool holder locking and releasing mechanism includes an actuator and a drive mechanism. When the drive mechanism operates in a first drive mode, the actuator can lock the tool holder, making the tool holder tightly fit with the tool holder assembly structure. When the drive mechanism operates in a second drive mode, the actuator releases the tool holder, allowing the tool holder to disengage from the tool holder assembly structure; a spindle cooling system includes a coolant channel network. The coolant channels in the coolant channel network are distributed within the shells of the spindle body, the front bearing housing, and the rear bearing housing, and are respectively connected to the machine tool coolant inlet and the machine tool coolant return outlet; the coolant channel network... The coolant channels distributed within the shell of the rear bearing housing include a rear bearing housing circumferential cooling channel, with a rear bearing housing circumferential cooling channel coolant inlet and outlet. The coolant channels distributed within the shell of the spindle body in the coolant channel network include a spindle body circumferential cooling channel and a spindle body axial flow channel. The spindle body circumferential cooling channel has a spindle body circumferential cooling channel coolant inlet and outlet, and the spindle body axial flow channel has a spindle body axial flow channel coolant inlet and outlet. The coolant channel network is distributed within the shell of the front bearing housing. The coolant channels within the layer include a front bearing housing circumferential cooling channel, on which a front bearing housing circumferential cooling channel coolant inlet and a front bearing housing circumferential cooling channel coolant outlet are distributed; wherein, the rear bearing housing circumferential cooling channel coolant inlet is connected to the machine tool coolant input interface, the rear bearing housing circumferential cooling channel coolant outlet is connected to the spindle body axial flow channel coolant inlet, the spindle body axial flow channel coolant outlet is connected to the front bearing housing circumferential cooling channel coolant inlet, the front bearing housing circumferential cooling channel coolant outlet is connected to the spindle body circumferential cooling channel coolant inlet, and the spindle body circumferential cooling channel coolant outlet is connected to the machine tool coolant return interface;When the spindle cooling system is working, the coolant flows through the rear bearing housing circumferential cooling channel, the spindle body circumferential cooling channel, and the front bearing housing circumferential cooling channel in the following order: first through the rear bearing housing circumferential cooling channel, then through the front bearing housing circumferential cooling channel, and finally through the spindle body circumferential cooling channel.

[0007] As an improvement and / or instance of the machine tool spindle in the first aspect above, further: the circumferential cooling channel of the rear bearing housing includes an annular groove on the outer wall of the rear bearing housing that is circumferentially arranged on the outer wall of the rear bearing housing and mates with the inner wall of the spindle body.

[0008] As an improvement and / or embodiment of the machine tool spindle in the first aspect mentioned above, further: the circumferential cooling channel of the spindle body includes a plurality of annular grooves evenly spaced along the axial direction on the outer wall of an intermediate sleeve sleeved between the inner wall of the spindle body and the outer wall of the motor stator. The outer wall of the intermediate sleeve is provided with a plurality of convex rings evenly spaced along the axial direction, such that an annular groove is formed between any two adjacent convex rings. Each of the plurality of convex rings has a recess, and the recesses of any two adjacent convex rings are 180° apart in the circumferential direction. Multiple convex rings are respectively adapted to the inner sidewall of the spindle body. A recess is opened on each of the multiple convex rings so that any two adjacent annular grooves on the outer sidewall of the intermediate sleeve are connected through the corresponding recess. The coolant inlet of the circumferential cooling channel of the spindle body is connected to the annular groove on the outer sidewall of the foremost intermediate sleeve and is 180° away from the recess on the convex ring at the foremost intermediate sleeve in the circumferential direction. The coolant outlet of the circumferential cooling channel of the spindle body is connected to the annular groove on the outer sidewall of the rearmost intermediate sleeve and is 180° away from the recess on the convex ring at the rearmost intermediate sleeve in the circumferential direction.

[0009] As an improvement and / or instance of the machine tool spindle in the first aspect above, further: the spindle body circumferential cooling channel includes a spiral groove on the outer wall of an intermediate sleeve that is sleeved between the inner wall of the spindle body and the outer wall of the motor stator; the coolant inlet of the spindle body circumferential cooling channel is located at the front end of the spiral groove on the outer wall of the intermediate sleeve; and the coolant outlet of the spindle body circumferential cooling channel is located at the rear end of the spiral groove on the outer wall of the intermediate sleeve.

[0010] As an improvement and / or instance of the machine tool spindle in the first aspect above, further: the spindle body axial flow channel is formed by a spindle body axial flow hole formed in the spindle body; the coolant inlet of the spindle body axial flow channel is located at the rear end of the spindle body axial flow hole, and the coolant outlet of the spindle body axial flow channel is located at the front end of the spindle body axial flow hole.

[0011] As an improvement and / or instantiation of the machine tool spindle in the first aspect above, further: the spindle body axial guide holes are two in number and the two spindle body axial guide holes are arranged close to each other.

[0012] As an improvement and / or instance of the machine tool spindle in the first aspect above, further: the front bearing housing has a front bearing housing body and an annular member fitted on the inner side of the front bearing housing body, the circumferential cooling channel of the front bearing housing is contained in an annular groove on the inner side wall of the front bearing housing body circumferentially disposed therein.

[0013] As an improvement and / or embodiment of the machine tool spindle in the first aspect mentioned above, further: a spindle body front end mounting flange is provided in the middle area of ​​the outer side of the front bearing housing body; a plurality of bolt axial mounting holes are circumferentially distributed on the front end mounting flange of the spindle body; the front end of the spindle body mates with the front end mounting flange of the spindle body and is connected together by bolts inserted into these bolt axial mounting holes; the circumferential cooling channel of the front bearing housing also includes a circumferentially arranged annular groove on the outer side wall of the front bearing housing body that mates with the inner side wall of the spindle body; an internal channel of the front bearing housing body is provided in the front bearing housing body to connect the annular groove on the inner side wall of the front bearing housing body with the annular groove on the outer side wall of the front bearing housing body; the coolant inlet of the circumferential cooling channel of the front bearing housing body is provided on the annular groove on the inner side wall of the front bearing housing body, and the coolant outlet of the circumferential cooling channel of the front bearing housing body is provided on the annular groove on the outer side wall of the front bearing housing body.

[0014] As an improvement and / or embodiment of the machine tool spindle in the first aspect mentioned above, further: the bottom of the annular groove on the inner side wall of the front bearing housing is provided with an arc-shaped flow-collecting groove, and the bottom of the arc-shaped flow-collecting groove is provided with two parallel coolant inlet holes, which respectively form the coolant inlets of the circumferential cooling channel of the front bearing housing; the spindle body axial flow channel is formed by the spindle body axial flow-guide hole opened in the spindle body; the coolant inlet of the spindle body axial flow channel is located at the rear end of the spindle body axial flow-guide hole, and the coolant outlet of the spindle body axial flow channel is located at the front end of the spindle body axial flow-guide hole; the number of the spindle body axial flow-guide holes is two, and the two spindle body axial flow-guide holes are arranged close to each other; the two coolant inlets correspond one-to-one with the two spindle body axial flow-guide holes.

[0015] As an improvement and / or instantiation of the machine tool spindle in the first aspect above, further: the coolant channels distributed in the shell of the spindle body in the coolant channel network also include spindle body axial output channels, and the coolant outlet of the spindle body circumferential cooling channel and the machine tool coolant return interface are connected through the spindle body axial output channels.

[0016] Secondly, a front bearing housing for a machine tool spindle is provided, comprising a front bearing housing body and a front bearing housing circumferential cooling channel disposed on the front bearing housing body. A front end mounting flange for the spindle body is provided in the middle region of the outer side of the front bearing housing body. A coolant inlet and a coolant outlet are distributed on the front bearing housing circumferential cooling channel. The front bearing housing circumferential cooling channel includes a circumferentially arranged annular groove on the inner wall of the front bearing housing body. The coolant inlet is disposed on the annular groove on the inner wall of the front bearing housing body. The front bearing housing circumferential cooling channel also includes a circumferentially arranged annular groove on the outer wall of the front bearing housing body, located after the front end mounting flange of the spindle body. The coolant outlet is disposed on the annular groove on the outer wall of the front bearing housing body. An internal channel is formed in the front bearing housing body that connects the annular groove on the inner wall of the front bearing housing body with the annular groove on the outer wall of the front bearing housing body.

[0017] As an improvement and / or instance of the machine tool spindle front bearing housing in the second aspect above, further: the bottom of the annular groove on the inner side wall of the front bearing housing body is provided with an arc-shaped flow collecting groove, and the bottom of the arc-shaped flow collecting groove is provided with two parallel coolant inlet holes, the two coolant inlet holes respectively forming the coolant inlet of the circumferential cooling channel of the front bearing housing.

[0018] As an improvement and / or instance of the front bearing housing of the machine tool spindle in the second aspect above, further: the front end mounting flange of the spindle body is provided with a plurality of bolt axial mounting holes distributed circumferentially.

[0019] The first aspect of the machine tool spindle mentioned above adopts a "rear-front-middle" cooling scheme (i.e., when the spindle cooling system is working, the coolant flows through the rear bearing housing circumferential cooling channel, the spindle body circumferential cooling channel, and the front bearing housing circumferential cooling channel in the following order: first through the rear bearing housing circumferential cooling channel, then through the front bearing housing circumferential cooling channel, and finally through the spindle body circumferential cooling channel). This effectively solves the shortcomings of the previous two schemes and optimizes the overall cooling effect. First, the rear bearing housing is cooled to prevent heat accumulation at the rear; then the front bearing housing is cooled to ensure the accuracy of the spindle front end; since the heat generated by the rear and front bearing housings is much smaller than that of the spindle body, the spindle body (including the motor stator) is cooled last, allowing for more uniform cooling using coolant at a moderate temperature. This sequence not only balances heat distribution and improves the thermal gradient but also optimizes the cooling effect on the main heat source (motor stator). More balanced temperature control helps maintain the high-precision operation of the spindle while improving the efficiency of the entire cooling system.

[0020] The front bearing housing of the machine tool spindle in the second aspect mentioned above is specifically designed for the machine tool spindle in the first aspect mentioned above, and can realize the conversion of coolant from the front bearing housing to the cooling channel and then to the spindle body to the cooling channel.

[0021] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0022] The accompanying drawings, which form part of this specification, are used to aid in understanding the invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the invention, but do not constitute an undue limitation of the invention.

[0023] Figure 1 This is a cross-sectional view of a machine tool spindle on the first section, according to an embodiment of the present invention.

[0024] Figure 2 for Figure 1 The machine tool spindle shown is a sectional view on the second section.

[0025] Figure 3 for Figure 1 The machine tool spindle shown is a sectional view on the third section.

[0026] The first, second, and third sections all pass through the central axis of the machine tool spindle, and there is a certain angle between the first, second, and third sections.

[0027] Figure 4 for Figure 1 An enlarged view of the front end of the machine tool spindle.

[0028] Figure 5 for Figure 1 The section view of the spindle cooling system of the machine tool spindle shown (section corresponding to the spindle) Figure 1 ).

[0029] Figure 6 for Figure 1 The section view of the spindle cooling system of the machine tool spindle shown (section corresponding to the spindle) Figure 2 ).

[0030] Figure 7 for Figure 1 The figure shows a 3D view of the front bearing housing of the machine tool spindle.

[0031] Figure 8 for Figure 1 The figure shows a 3D view of the front bearing housing of the machine tool spindle.

[0032] Figure 9 for Figure 1 A partial sectional view of the front bearing housing of the machine tool spindle shown.

[0033] Figure 10 for Figure 1 The image shows a photograph of the actual machine tool spindle.

[0034] Figure 11 for Figure 1 The image shows a photograph of the front bearing housing of the machine tool spindle. Detailed Implementation

[0035] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0036] The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0037] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0038] Regarding the terminology and units in this specification: The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Furthermore, other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0039] like Figures 1-9As shown, a machine tool spindle includes: a spindle body 1; a spindle motor comprising a stator and a rotor, the stator being fixed in the spindle body 1 and the rotor being adapted to the stator; a spindle core 3 rotatably mounted in the spindle body 1 via a front bearing system 4 and a rear bearing system 5 and rotating with the rotor, the front end of the spindle core 3 having a tool holder assembly structure; a front bearing system 4 comprising a front bearing housing and a front bearing, the front bearing housing being disposed at the front end of the spindle body, the front bearing being mounted in the front bearing housing and rotatably supporting the front part of the spindle core; and a rear bearing system. 5. The rear bearing system includes a rear bearing housing and a rear bearing. The rear bearing housing is located at the rear end of the spindle body, and the rear bearing is installed in the rear bearing housing and rotatably supports the rear part of the spindle core; 6. Tool holder locking and releasing mechanism 6 includes an actuator and a drive mechanism. When the drive mechanism operates in a first driving mode, the actuator can lock the tool holder so that the tool holder is tightly engaged with the tool holder assembly structure. When the drive mechanism operates in a second driving mode, the actuator releases the tool holder so that the tool holder can disengage from the tool holder assembly structure; 7. Spindle cooling system 7 includes a cooling... A coolant channel network is provided, in which coolant channels are distributed within the shells of the spindle body 1, the front bearing housing, and the rear bearing housing, and are respectively connected to the machine tool coolant inlet 7a and the machine tool coolant return interface 7b; the coolant channels distributed within the shell of the rear bearing housing include a rear bearing housing circumferential cooling channel 71, on which a rear bearing housing circumferential cooling channel coolant inlet and a rear bearing housing circumferential cooling channel coolant outlet are distributed; the coolant channels distributed within the shell of the spindle body 1 include the spindle body... The system includes a circumferential cooling channel 72 and a spindle body axial flow channel 73. The circumferential cooling channel has a coolant inlet and a coolant outlet. The axial flow channel also has a coolant inlet and an outlet. The coolant channel network located within the shell of the front bearing housing includes a front bearing housing circumferential cooling channel 74, which has a coolant inlet and an outlet.The rear bearing housing circumferential cooling channel coolant inlet is connected to the machine tool coolant input interface; the rear bearing housing circumferential cooling channel coolant outlet is connected to the spindle body axial flow channel coolant inlet; the spindle body axial flow channel coolant outlet is connected to the front bearing housing circumferential cooling channel coolant inlet; the front bearing housing circumferential cooling channel coolant outlet is connected to the spindle body circumferential cooling channel coolant inlet; and the spindle body circumferential cooling channel coolant outlet is connected to the machine tool coolant return interface. When the spindle cooling system is working, the coolant flows through the rear bearing housing circumferential cooling channel 71, the spindle body circumferential cooling channel 72, and the front bearing housing circumferential cooling channel 74 in the following order: first through the rear bearing housing circumferential cooling channel 71, then through the front bearing housing circumferential cooling channel 74, and finally through the spindle body circumferential cooling channel 72.

[0040] The aforementioned machine tool spindle adopts a "rear-front-middle" cooling scheme (i.e., when the spindle cooling system 7 is working, the coolant flows through the rear bearing housing circumferential cooling channel 71, the spindle body circumferential cooling channel 72, and the front bearing housing circumferential cooling channel 74 in the following order: first through the rear bearing housing circumferential cooling channel 71, then through the front bearing housing circumferential cooling channel 74, and finally through the spindle body circumferential cooling channel 72). This effectively solves the shortcomings of the previous two schemes and optimizes the overall cooling effect. First, the rear bearing housing is cooled to prevent heat accumulation at the rear; then the front bearing housing is cooled to ensure the accuracy of the spindle front end; since the heat generated by the rear and front bearing housings is much smaller than that of the spindle body, the spindle body 1 (including the motor stator) is cooled last, allowing for more uniform cooling using coolant at a moderate temperature. This sequence not only balances the heat distribution and improves the thermal gradient but also optimizes the cooling effect on the main heat source (motor stator). More balanced temperature control helps maintain high-precision spindle operation while improving the efficiency of the entire cooling system.

[0041] The rear bearing housing circumferential cooling channel 71 includes an annular groove on the outer wall of the rear bearing housing that circumferentially mates with the inner wall of the spindle body 1.

[0042] The circumferential cooling channel 72 of the main spindle body can adopt the solution provided by the applicant in the patent application document with application number 202311546879.5. That is, the circumferential cooling channel 72 of the main spindle body includes a plurality of annular grooves on the outer wall of the intermediate sleeve 11, which is sleeved between the inner side wall of the main spindle body 1 and the outer side wall of the motor stator, arranged axially at uniform intervals. The outer wall of the intermediate sleeve is provided with a plurality of convex rings arranged axially at uniform intervals, such that an annular groove is formed between any two adjacent convex rings. Each of the plurality of convex rings has a recess, and the recesses of any two adjacent convex rings are circumferentially spaced apart. The circumferential orientations differ by 180°. The plurality of convex rings are respectively adapted to the inner sidewall of the spindle body. A recess is opened on each of the plurality of convex rings so that any two adjacent annular grooves on the outer sidewall of the intermediate sleeve are connected through the corresponding recess. The coolant inlet of the circumferential cooling channel of the spindle body is connected to the annular groove on the outer sidewall of the foremost intermediate sleeve and is 180° away from the recess on the convex ring at the foremost intermediate sleeve in the circumferential orientation. The coolant outlet of the circumferential cooling channel of the spindle body is connected to the annular groove on the outer sidewall of the foremost intermediate sleeve and is 180° away from the recess on the convex ring at the foremost intermediate sleeve in the circumferential orientation.

[0043] In another specific embodiment, the spindle body circumferential cooling channel 72 may include a spiral groove on the outer wall of the intermediate sleeve 11, which is sleeved between the inner side wall of the spindle body 1 and the outer side wall of the motor stator. The coolant inlet of the spindle body circumferential cooling channel is located at the front end of the spiral groove on the outer wall of the intermediate sleeve, and the coolant outlet of the spindle body circumferential cooling channel is located at the rear end of the spiral groove on the outer wall of the intermediate sleeve.

[0044] The spindle body axial flow channel 73 is formed by a spindle body axial flow hole formed in the spindle body; the coolant inlet of the spindle body axial flow channel is located at the rear end of the spindle body axial flow hole, and the coolant outlet of the spindle body axial flow channel is located at the front end of the spindle body axial flow hole.

[0045] Specifically, the spindle body can have two axial flow guide holes, and these two axial flow guide holes are arranged close to each other. Since the number of axial flow guide holes in the spindle body is small (two), this helps to improve the strength of the spindle body 1.

[0046] The front bearing housing has a front bearing housing body 41 and an annular member 42 that is fitted and installed on the inner side of the front bearing housing body 41. The circumferential cooling channel 74 of the front bearing housing includes an annular groove 741 on the inner side wall of the front bearing housing body 41 that is circumferentially arranged on the inner side wall of the front bearing housing body 41. Furthermore, the middle area of ​​the outer side of the front bearing housing body 41 is provided with a front end mounting flange 43 of the spindle body. The front end mounting flange 43 of the spindle body has a plurality of bolt axial mounting holes distributed circumferentially. The front end of the spindle body 1 mates with the front end mounting flange 43 of the spindle body and is connected together by bolts 44 inserted into these bolt axial mounting holes. The circumferential cooling channel 74 of the front bearing housing also includes a circumferentially arranged annular groove 742 on the outer side wall of the front bearing housing body 41 that mates with the inner side wall of the spindle body 1. The front bearing housing body 41 has an internal channel that connects the annular groove 741 on the inner side wall of the front bearing housing body with the annular groove 742 on the outer side wall of the front bearing housing body. The coolant inlet of the circumferential cooling channel of the front bearing housing is located on the annular groove 741 on the inner side wall of the front bearing housing body, and the coolant outlet of the circumferential cooling channel of the front bearing housing is located on the annular groove 742 on the outer side wall of the front bearing housing body.

[0047] The advantages of this design are mainly as follows: First, the annular groove structure on the inner and outer walls of the front bearing housing body 41 (annular groove 741 on the inner wall of the front bearing housing body and annular groove 742 on the outer wall of the front bearing housing body) and the internal channel of the front bearing housing body form a highly efficient cooling circuit that can fully cover the front bearing housing area, ensuring uniform cooling. Second, the front mounting flange 43 and bolt connection of the spindle body front end securely and reliably mount the front bearing housing body 41 to the spindle body 1. The annular groove 741 on the inner wall of the front bearing housing body and the annular groove 742 on the outer wall of the front bearing housing body are located on both sides of the front mounting flange 43 of the spindle body, which facilitates the passage of the front bearing housing circumferential cooling channel 74 through the channel opened in the spindle body 1 (see...). Figure 6 The transition to the circumferential cooling channel 72 of the spindle body shows that this structural design not only optimizes the cooling effect but also takes into account assembly convenience and structural stability.

[0048] The bottom of the annular groove 741 on the inner side wall of the front bearing housing is provided with an arc-shaped flow-collecting groove 743. The bottom of the arc-shaped flow-collecting groove 743 has two parallel coolant inlet holes, which respectively form the coolant inlets of the circumferential cooling channel of the front bearing housing. The spindle body axial flow channel 73 is formed by the spindle body axial flow channel formed in the spindle body 1. The coolant inlet of the spindle body axial flow channel is located at the rear end of the spindle body axial flow channel, and the coolant outlet of the spindle body axial flow channel is located at the front end of the spindle body axial flow channel. There are two spindle body axial flow channels, and these two spindle body axial flow channels are arranged close to each other. The two coolant inlets correspond one-to-one with the two spindle body axial flow channels.

[0049] The arc-shaped collecting groove 743 effectively collects and distributes coolant. The design of two parallel coolant inlets corresponding one-to-one with the two axial guide holes of the spindle body ensures uniform distribution and flow of coolant. The coolant then flows in two different directions using the guiding effect of the arc-shaped collecting groove 743, rapidly cooling the front bearing housing. The number of axial guide holes in the spindle body is limited to two and placed close together, ensuring sufficient cooling while maximizing the structural strength of the spindle body 1.

[0050] The coolant channels distributed within the shell of the spindle body in the coolant channel network also include spindle body axial output channels. The coolant outlet of the spindle body circumferential cooling channel and the machine tool coolant return interface are connected through the spindle body axial output channels.

[0051] The present invention has been described above. Those skilled in the art will be able to implement the present invention based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of patent protection.

Claims

1. Machine tool spindle, including: Main spindle body; A spindle motor, comprising a motor stator and a motor rotor, wherein the motor stator is fixed in the spindle body and the motor rotor is adapted to the motor stator; The shaft core is rotatably mounted in the main shaft body via a front bearing system and a rear bearing system and rotates with the motor rotor. The front end of the shaft core is provided with a tool holder assembly structure. A front bearing system, comprising a front bearing housing and a front bearing, wherein the front bearing housing is disposed at the front end of the main shaft body, and the front bearing is installed in the front bearing housing and rotatably supports the front part of the shaft core; The rear bearing system includes a rear bearing housing and a rear bearing. The rear bearing housing is disposed at the rear end of the main shaft body, and the rear bearing is installed in the rear bearing housing and rotatably supports the rear part of the shaft core. A tool holder locking and releasing mechanism includes an actuator and a drive mechanism. When the drive mechanism operates in a first driving mode, the actuator can lock the tool holder so that the tool holder is tightly engaged with the tool holder assembly structure. When the drive mechanism operates in a second driving mode, the actuator releases the tool holder so that the tool holder can disengage from the tool holder assembly structure. A spindle cooling system includes a coolant channel network. The coolant channels in the coolant channel network are distributed within the shells of the spindle body, the front bearing housing, and the rear bearing housing, and are respectively connected to the machine tool coolant input interface and the machine tool coolant return interface. Its features are: The coolant channels distributed within the shell of the rear bearing housing in the coolant channel network include a rear bearing housing circumferential cooling channel, on which a rear bearing housing circumferential cooling channel coolant inlet and a rear bearing housing circumferential cooling channel coolant outlet are distributed. The coolant channel network distributed within the shell of the spindle body includes a spindle body circumferential cooling channel and a spindle body axial flow channel. The spindle body circumferential cooling channel has a spindle body circumferential cooling channel coolant inlet and a spindle body circumferential cooling channel coolant outlet. The spindle body axial flow channel has a spindle body axial flow channel coolant inlet and a spindle body axial flow channel coolant outlet. The coolant channels distributed within the shell of the front bearing housing in the coolant channel network include a front bearing housing circumferential cooling channel, on which a front bearing housing circumferential cooling channel coolant inlet and a front bearing housing circumferential cooling channel coolant outlet are distributed. Specifically, the coolant inlet of the rear bearing housing circumferential cooling channel is connected to the machine tool coolant input interface; the coolant outlet of the rear bearing housing circumferential cooling channel is connected to the coolant inlet of the spindle body axial flow channel; the coolant outlet of the spindle body axial flow channel is connected to the coolant inlet of the front bearing housing circumferential cooling channel; the coolant outlet of the front bearing housing circumferential cooling channel is connected to the coolant inlet of the spindle body circumferential cooling channel; and the coolant outlet of the spindle body circumferential cooling channel is connected to the machine tool coolant return interface. When the spindle cooling system is working, the coolant flows through the rear bearing housing circumferential cooling channel, the spindle body circumferential cooling channel, and the front bearing housing circumferential cooling channel in the following order: first through the rear bearing housing circumferential cooling channel, then through the front bearing housing circumferential cooling channel, and finally through the spindle body circumferential cooling channel. The front bearing housing has a front bearing housing body and an annular member that is fitted and installed on the inner side of the front bearing housing body. The circumferential cooling channel of the front bearing housing is contained in an annular groove on the inner side wall of the front bearing housing body that is circumferentially disposed on the inner side wall of the front bearing housing body. The outer side of the front bearing housing body has a spindle body front end mounting flange in the middle area. The spindle body front end mounting flange has multiple bolt axial mounting holes distributed circumferentially. The front end of the spindle body mates with the spindle body front end mounting flange and is connected by bolts inserted into these bolt axial mounting holes. The front bearing housing circumferential cooling channel also includes a circumferentially arranged annular groove on the outer wall of the front bearing housing body that mates with the inner wall of the spindle body. An internal channel is formed in the front bearing housing body that connects the annular groove on the inner wall of the front bearing housing body with the annular groove on the outer wall of the front bearing housing body. The coolant inlet of the front bearing housing circumferential cooling channel is located on the annular groove on the inner wall of the front bearing housing body, and the coolant outlet of the front bearing housing circumferential cooling channel is located on the annular groove on the outer wall of the front bearing housing body.

2. The machine tool spindle as described in claim 1, characterized in that: The rear bearing housing circumferential cooling channel includes an annular groove on the outer wall of the rear bearing housing that circumferentially mates with the inner wall of the main shaft body.

3. The machine tool spindle as described in claim 1, characterized in that: The circumferential cooling channel of the spindle body includes a plurality of annular grooves evenly spaced along the axial direction on the outer wall of an intermediate sleeve fitted between the inner wall of the spindle body and the outer wall of the motor stator. The outer wall of the intermediate sleeve is provided with a plurality of convex rings evenly spaced along the axial direction, such that an annular groove is formed between any two adjacent convex rings. Each of the plurality of convex rings has a recess, and the recesses of any two adjacent convex rings are 180° apart in the circumferential direction. The plurality of convex rings are respectively connected to the inner side of the spindle body. The wall profiles are adapted such that a recess is formed on each of the plurality of convex rings, allowing any two adjacent annular grooves on the outer wall of the intermediate sleeve to be connected through the corresponding recess; the coolant inlet of the circumferential cooling channel of the main shaft body is connected to the annular groove on the outer wall of the intermediate sleeve at the foremost end of the intermediate sleeve and is 180° away from the recess on the convex ring at the foremost end of the intermediate sleeve in the circumferential orientation; the coolant outlet of the circumferential cooling channel of the main shaft body is connected to the annular groove on the outer wall of the intermediate sleeve at the rearmost end of the intermediate sleeve and is 180° away from the recess on the convex ring at the rearmost end of the intermediate sleeve in the circumferential orientation.

4. The machine tool spindle as described in claim 1, characterized in that: The circumferential cooling channel of the spindle body includes a spiral groove on the outer wall of the intermediate sleeve, which is sleeved between the inner wall of the spindle body and the outer wall of the motor stator. The coolant inlet of the circumferential cooling channel of the spindle body is located at the front end of the spiral groove on the outer wall of the intermediate sleeve, and the coolant outlet of the circumferential cooling channel of the spindle body is located at the rear end of the spiral groove on the outer wall of the intermediate sleeve.

5. The machine tool spindle as described in claim 3 or 4, characterized in that: The spindle body axial flow channel is formed by a spindle body axial flow hole formed in the spindle body; the coolant inlet of the spindle body axial flow channel is located at the rear end of the spindle body axial flow hole, and the coolant outlet of the spindle body axial flow channel is located at the front end of the spindle body axial flow hole.

6. The machine tool spindle as described in claim 5, characterized in that: The spindle body has two axial guide holes, and these two axial guide holes are arranged close to each other.

7. The machine tool spindle as described in claim 1, characterized in that: The bottom of the annular groove on the inner side wall of the front bearing housing is provided with an arc-shaped flow-collecting groove. Two parallel coolant inlet holes are formed at the bottom of the arc-shaped flow-collecting groove, each forming a coolant inlet in the circumferential cooling channel of the front bearing housing. The spindle body axial flow channel is formed by spindle body axial flow holes formed within the spindle body. The coolant inlet of the spindle body axial flow channel is located at the rear end of the spindle body axial flow hole, and the coolant outlet is located at the front end of the spindle body axial flow hole. There are two spindle body axial flow holes, and these two spindle body axial flow holes are arranged close to each other. The two coolant inlet holes correspond one-to-one with the two spindle body axial flow holes.

8. The machine tool spindle as described in claim 1, characterized in that: The coolant channels distributed within the shell of the spindle body in the coolant channel network also include spindle body axial output channels. The coolant outlet of the spindle body circumferential cooling channel and the machine tool coolant return interface are connected through the spindle body axial output channels.

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