Telescopic electric spindle and machine tool

Abstract

The telescopic electric spindle comprises a machine body, a shaft core, a pull rod and a driving cylinder, the shaft core is installed on the machine body through a first bearing, the machine body is provided with a stator, the shaft core is provided with a rotor, the shaft core is provided with a center hole penetrating in the axial direction, the pull rod is installed in the center hole, and the outer surface of the pull rod is in sliding fit with the hole wall of the center hole. An oil storage groove is formed in the outer surface, in sliding fit with the hole wall of the center hole, of the pull rod, the pull rod is matched with the shaft core through a notch extending in the axial direction, the pull rod rotates synchronously along with the shaft core, and the rear end of the pull rod is in linkage with a piston of the driving cylinder through a second bearing. According to the technical scheme, the pull rod is made of the nodular cast iron material, and the nodular cast iron material contains graphite, so that the material has a self-lubricating effect and very high wear resistance, and the design of a steel ball sleeve or an oil-free self-lubricating bearing of the main shaft in the technical scheme is omitted, so that the shaft diameter of the pull rod is increased, and the rigidity is improved.

Description

Technical Field

[0001] The utility model is used in the field of mechanical processing spindles, in particular to a telescopic electric spindle and a machine tool. Background Art

[0002] At present, the mechanical processing industry is growing, and the requirements for the functions, performance and work efficiency of machine tools are constantly increasing. As the core functional component of machine tools, the structural function of the electric spindle limits the overall development of the machine tool industry. For example, due to structural limitations, the pull rod inside the shaft core of the traditional grinding machine cannot be lubricated by later oiling after installation. Therefore, in most spindle designs, the pull rod is made of stainless steel, and the pull rod and the inner hole of the shaft core are designed with a steel ball sleeve or an oil-free self-lubricating bearing to ensure the long-term stability of the pull rod sliding. However, the shaft diameter of the pull rod will be smaller as a whole, resulting in a decrease in the rigidity of the pull rod, affecting the spindle performance. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art and to provide a telescopic electric spindle and a machine tool.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] In the first aspect, a telescopic electric spindle comprises a body, a shaft core, a pull rod and a drive cylinder, the shaft core is installed on the body through a first bearing, the body is provided with a stator, the shaft core is provided with a rotor, the shaft core is provided with a center hole extending axially, the pull rod is installed in the center hole, the outer surface of the pull rod is slidably matched with the hole wall of the center hole, the pull rod is provided with an oil storage groove on the outer surface that is slidably matched with the hole wall of the center hole, the pull rod and the shaft core are matched through a notch extending along the axial direction, so that the pull rod rotates synchronously with the shaft core, and the rear end of the pull rod is linked to the piston of the drive cylinder through a second bearing.

[0006] In combination with the first aspect, in certain implementations of the first aspect, the pull rod is provided with an oil storage groove on the outer surface that slides with the hole wall of the center hole, and the oil storage groove is formed on the outer surface of the pull rod by a scraping process.

[0007] In combination with the first aspect and the above-mentioned implementation methods, in certain implementation methods of the first aspect, the rear end of the shaft core is provided with a shaft end pressure cover, the shaft end pressure cover is provided with a guide hole for the pull rod to pass through, the shaft end pressure cover is provided with teeth protruding into the guide hole, the pull rod is provided with a notch extending in the axial direction, the teeth cooperate with the notch, so that the pull rod rotates synchronously with the shaft core.

[0008] In combination with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, the piston of the driving cylinder is connected to the bearing seat, the inner ring of the second bearing is locked to the pull rod by a first locking nut, and the outer ring of the second bearing is locked to the bearing seat by an outer ring pressure cover, and the driving cylinder includes a primary cylinder body, a secondary cylinder body and a tertiary cylinder body, a primary piston is provided in the primary cylinder body, a secondary piston is provided in the secondary cylinder body, the bearing seat is arranged in the tertiary cylinder body, the primary piston acts on the secondary piston, and the secondary piston acts on the bearing seat.

[0009] In combination with the first aspect and the above-mentioned implementations, in some implementations of the first aspect, a pressure sensor for cooperating with the bearing seat is provided in front of the bearing seat along the driving direction of the driving cylinder.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in certain implementation methods of the first aspect, the shaft core is provided with a first mounting groove, a second mounting groove and a third mounting groove in sequence along the direction in which the pull rod extends outward at the front end of the center hole, the first mounting groove is provided with an O-ring that cooperates with the pull rod, the second mounting groove is provided with a skeleton oil seal that cooperates with the pull rod, and the third mounting groove is provided with an elastic retaining ring.

[0011] In combination with the first aspect and the above-mentioned implementations, in some implementations of the first aspect, a body front cover is provided at the front end of the body, a second locking nut is provided at the front end of the shaft core, and the body front cover and the second locking nut are clearance-matched to form a labyrinth sealing structure.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, an air sealing ring is provided between the front cover of the body and the second locking nut, and the air sealing ring is provided with an annular groove on the outer peripheral surface of the side facing the front cover of the body, the air sealing ring is tightly fitted with the front cover of the body, and the air sealing ring and the second locking nut are loosely matched, and a plurality of air holes connected to the labyrinth sealing structure are provided along the circumference of the annular groove.

[0013] In combination with the first aspect and the above-mentioned implementations, in certain implementations of the first aspect, the stator is installed in the inner hole of the body, a spiral water groove is provided on the outer circle of the body, a sleeve is provided on the outside of the body, the sleeve seals the spiral water groove, and an inlet and outlet water joint is provided at the rear end of the body.

[0014] In a second aspect, a machine tool comprises the telescopic electric spindle described in any implementation of the first aspect.

[0015] One of the above technical solutions has at least one of the following advantages or beneficial effects: In the technical solution of the utility model, the pull rod is completely sleeved inside the shaft core, and the shaft core and the pull rod are matched through the notch, so that the shaft core and the pull rod can rotate synchronously; a driving cylinder is designed at the rear end of the pull rod, and under the action of the driving cylinder, the second bearing slides telescopically with the piston inside the driving cylinder, thereby driving the pull rod to slide. The main shaft of the utility model has a telescopic characteristic, breaking the traditional main shaft structure design and improving the compatibility of the main shaft. The design of the driving cylinder not only provides power for the extension and contraction of the pull rod, but also provides a certain rigidity for the pull rod. The pull rod in the technical solution of the utility model is provided with an oil storage groove on the outer surface that slides with the hole wall of the center hole, so that there are many oil storage grooves on the outer circle to store oil, thereby improving the lubrication effect of the pull rod, ensuring the long-term stability of the pull rod sliding, and thus improving the service life of the main shaft. Therefore, the main shaft of the technical solution of the utility model cancels the design of the steel ball sleeve or the oil-free self-lubricating bearing, so that the shaft diameter of the pull rod is increased and the rigidity is improved.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0018] Figure 1 This is a schematic structural diagram of an embodiment of the telescopic electric spindle of the utility model;

[0019] Figure 2 yes Figure 1 A schematic diagram of a pull rod structure of an embodiment is shown;

[0020] Figure 3 yes Figure 1 A schematic diagram of the structure of a driving cylinder and a pull rod in one embodiment is shown;

[0021] Figure 4 yes Figure 1 A schematic diagram of the sealing structure of the front end of a telescopic electric spindle according to an embodiment is shown;

[0022] Figure 5 yes Figure 1 A schematic diagram of the structure of an air sealing ring in one embodiment is shown;

[0023] Figure 6 yes Figure 1 A schematic diagram of the spiral water tank structure of a machine body of an embodiment is shown. DETAILED DESCRIPTION

[0024] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0025] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0026] In the present utility model, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present utility model, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0027] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0028] in, Figure 1 The reference direction coordinate system of the embodiment of the utility model is given below. Figure 1 The embodiment of the utility model is described with reference to the direction shown.

[0029] See also Figure 1The embodiment of the utility model provides a telescopic electric spindle, including a body 100, a shaft core 200, a pull rod 300 and a driving cylinder 400, the shaft core 200 is installed on the body 100 through a first bearing 101, the body 100 is provided with a stator 102, and the shaft core 200 is provided with a rotor 201, wherein the stator 102 and the rotor 201 are located in the middle of the body 100, and the first bearing 101 is arranged at the front end and the rear end of the body 100 to support the shaft core 200 on the body 10 0, the shaft core 200 is provided with a center hole extending axially therethrough, the pull rod 300 is installed in the center hole, the outer surface of the pull rod 300 is slidably matched with the hole wall of the center hole, the pull rod 300 is provided with an oil storage groove 301 on the outer surface that is slidably matched with the hole wall of the center hole, the pull rod 300 and the shaft core 200 are matched through a notch extending along the axial direction, so that the pull rod 300 rotates synchronously with the shaft core 200, and the rear end of the pull rod 300 is linked to the piston of the drive cylinder 400 through the second bearing 402.

[0030] In the technical solution of the utility model, the pull rod 300 is completely sleeved inside the shaft core 200, and the shaft core 200 and the pull rod 300 are matched through the notch, so that the shaft core 200 and the pull rod 300 can rotate synchronously; a drive cylinder 400 is designed at the rear end of the pull rod 300. Under the action of the drive cylinder 400, the second bearing 402 slides with the piston inside the drive cylinder 400, and then drives the pull rod 300 to slide. The main shaft of the utility model has a retractable characteristic, breaking the traditional main shaft structure design, improving the compatibility of the main shaft, and can be applied to most processing conditions according to actual needs. The design of the drive cylinder 400 not only provides power for the extension and contraction of the pull rod 300, but also provides a certain rigidity for the pull rod 300, otherwise it affects the processing accuracy of the main shaft, and plays an indispensable role in the main shaft. The pull rod in the technical solution of the utility model is provided with oil storage grooves on the outer surface which slides with the wall of the center hole, so that there are many oil storage grooves on the outer circle for storing oil, thereby improving the lubrication effect of the pull rod and ensuring the long-term stability of the sliding of the pull rod, thereby increasing the service life of the main shaft. Therefore, the main shaft of the technical solution of the utility model cancels the design of the steel ball sleeve or the oil-free self-lubricating bearing, so that the pull rod shaft diameter is increased and the rigidity is improved.

[0031] In some embodiments, see Figure 2 The oil storage grooves 301 are formed on the outer surface of the pull rod 300 by scraping. The outer circle of the pull rod 300 is scraped so that there are many oil storage grooves 301 on the outer circle for storing oil, thereby improving the lubrication effect of the pull rod 300 and ensuring the long-term stability of the sliding of the pull rod 300, thereby increasing the service life of the spindle.

[0032] The pull rod 300 and the shaft core 200 are matched with each other through a slot extending along the axial direction, wherein the slot can be set on the pull rod 300 or the shaft core 200, so that the pull rod 300 rotates synchronously with the shaft core 200 and can be extended and retracted along the axial direction.

[0033] In some embodiments, see Figure 1 , Figure 2 The rear end of the shaft core 200 is provided with a shaft end gland 202, which is provided with a guide hole for the pull rod 300 to pass through, and the shaft end gland 202 is provided with teeth protruding into the guide hole, and the pull rod 300 is provided with a notch 302 extending along the axial direction, and the teeth and the notch cooperate to make the pull rod 300 rotate synchronously with the shaft core 200. The design of the shaft end gland 202 plays a transmission role and also plays a guiding role in the sliding of the pull rod 300, making the axial telescopic movement of the pull rod 300 more stable.

[0034] In some embodiments, see Figure 1 , Figure 3 The piston of the driving cylinder 400 is connected to the bearing seat 401, the inner ring of the second bearing 402 is locked to the pull rod 300 through the first locking nut 403, and the outer ring of the second bearing 402 is locked to the bearing seat 401 through the outer ring pressure cover 404. The driving cylinder 400 includes a primary cylinder body, a secondary cylinder body and a tertiary cylinder body. The primary cylinder body is provided with a primary piston, the secondary cylinder body is provided with a secondary piston, the bearing seat 401 is arranged in the tertiary cylinder body, the primary piston acts on the secondary piston, and the secondary piston acts on the bearing seat 401.

[0035] Specifically, the driving cylinder 400 at the rear end can be an air cylinder or an oil cylinder. The driving cylinder 400 is the power source for the extension and retraction of the pull rod 300. At the same time, during the operation of the pull rod 300, the driving cylinder 400 must always maintain a constant pressure to provide a certain rigidity to the pull rod 300, otherwise it will affect the processing accuracy of the main shaft; the pull rod 300 is designed with a second bearing 402 that extends and retracts with the piston. The outer ring of the second bearing 402 is completely fixed in the bearing seat 401 in the cylinder by the outer ring pressure cover 404. When the bearing seat 401 slides axially with the piston, the second bearing 402 drives the pull rod 300 to slide axially. Therefore, the pull rod 300 and the driving cylinder 400 and the second bearing 402 at the rear end can be regarded as another axis system of the main shaft. When processing products with complex technology, the main shaft can exert its extension and retraction function to produce different effects on the products.

[0036] In some embodiments, see Figure 3 , along the driving direction of the drive cylinder, a pressure sensor 405 for cooperating with the bearing seat 401 is provided in front of the bearing seat 401. In this embodiment, a suitable range of the pressure sensor 405 is selected according to the thrust of the main shaft drive cylinder 400. The pressure sensor 405 has a threaded hole at the bottom, and is installed in front of the bearing seat 401 of the telescopic bearing using screws, such as Figure 3As shown, when the piston is in the extended state, the bearing seat 401 continuously applies a constant pressure to the force point on the pressure sensor 405. The pressure sensor 405 transmits an electrical signal to the corresponding signal receiving converter in the machine tool, which can monitor the thrust of the drive cylinder 400 in real time, thereby monitoring the bearing load condition, and can also control the intake (or oil) size according to the numerical feedback of the pressure sensor 405 to control the thrust of the drive cylinder 400.

[0037] A micro pressure sensor 405 is designed and installed inside the spindle, which can monitor the thrust of the drive cylinder in real time after the spindle tie rod 300 is extended, so as to monitor the bearing load of the spindle in real time. The machine tool modifies the processing parameters according to the bearing load to extend the service life of the bearing. The pressure sensor 405 can also be linked with the machine tool to set an alarm program. When the spindle is installed or other phenomena that cause abnormal pressure changes occur, the alarm program is activated and the machine tool stops working immediately, which can avoid damage to the bearing caused by installation.

[0038] Machine tools are the core of mechanical processing. Their working environment cannot be separated from dust and water. The spindle is the core component of the machine tool, so the high-reliability sealing structure design of the spindle is crucial.

[0039] In some embodiments, see Figure 4 In view of the telescopic characteristics of the spindle pull rod 300, a high-reliability sealing structure is designed for the front end of the spindle. In order to prevent dust and grinding fluid generated by grinding from entering the gap, the shaft core 200 is provided with a first mounting groove, a second mounting groove and a third mounting groove in sequence along the direction in which the pull rod 300 extends outward, in the first mounting groove, an O-ring 203 cooperating with the pull rod 300 is provided, in the second mounting groove, a skeleton oil seal 204 cooperating with the pull rod 300 is provided, and in the third mounting groove, an elastic retaining ring 205 is provided. The design purpose of the elastic retaining ring 205 is to prevent the skeleton oil seal 204 from falling off and ensure the stability of the seal. The sealing structure of the telescopic rod 300 is formed by the O-ring 203, the skeleton oil seal 204 and the elastic retaining ring 205, which mainly prevents the dust generated by grinding from entering the gap between the rod 300 and the shaft core 200, effectively ensuring the stability of the telescopic extension of the rod 300, and avoiding scratching the outer circle of the rod 300 or the inner hole of the shaft core 200, which may cause the extension and retraction of the rod 300 to become stuck and affect the performance of the spindle.

[0040] Further, in some embodiments, see Figure 4 The front end of the body 100 is provided with a body front cover 103, the front end of the shaft core 200 is provided with a second locking nut 206, and the body front cover 103 and the second locking nut 206 are clearance-matched to form a labyrinth seal structure. The labyrinth seal structure is located at the front end of the first bearing 101, which can prevent the grinding fluid or dust in the environment from entering the bearing, thereby causing damage to the bearing.

[0041] For further information, see Figure 4 , Figure 5 An air seal ring 207 is provided between the front cover 103 of the machine body and the second locking nut 206. The air seal ring 207 is provided with an annular groove 208 on the outer peripheral surface on the side facing the front cover 103 of the machine body. The air seal ring 207 is tightly fitted with the front cover 103 of the machine body. The air seal ring 207 and the second locking nut 206 are loosely matched. A plurality of air holes 209 connected with the labyrinth seal structure are provided along the circumference of the annular groove 208 to form an air curtain. A plurality of bosses and grooves are designed on the mating surfaces of the front cover 103 of the machine body and the second locking nut 206. The front cover 103 of the machine body and the second locking nut 206 are in an inverted design to form a labyrinth, which increases the air flow resistance and prevents the air seal compressed air from flowing back. The outer circle of the air seal ring 207 is designed with a plurality of air holes, such as Figure 4 As shown, after the compressed air flows through the air seal ring 207, an air curtain flowing outward is formed, thereby preventing external water vapor and dust from entering the interior of the main shaft, thereby achieving a sealing effect.

[0042] In some embodiments, see Figure 1 , Figure 6 The stator 102 is installed in the inner hole of the body 100. In order to cool the main shaft stator 102 and the bearing, a spiral water groove 104 is provided on the outer circle of the body 100, and a sleeve 105 is provided on the outer side of the body 100. The sleeve 105 seals the spiral water groove 104, and the rear end of the body 100 is provided with an inlet and outlet water joint. The cooling water flows into the spiral water channel in the body 100 from the inlet, takes away the heat generated by the bearing and the stator 102, so that the bearing and the stator 102 still maintain a low temperature during the working process, improve the stability of the main shaft, and good cooling increases the service life of the main shaft; reduce the thermal elongation of the main shaft. Compared with the prior art designing multiple straight hole water channels on the body 100, the embodiment of the utility model increases the contact area of ​​the cooling water by designing a spiral circulating water channel structure on the outer circle of the body 100, which can take away most of the heat generated by the stator 102 and the bearing, and the overall processing cost is low.

[0043] An embodiment of the utility model further provides a machine tool, comprising the telescopic electric spindle in any of the above embodiments.

[0044] In the description of this specification, the description with reference to the terms "example", "embodiment" or "some embodiments" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0045] Of course, the invention is not limited to the above-mentioned embodiments, and those skilled in the art may make equivalent modifications or substitutions without violating the spirit of the invention, and these equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A telescopic electric spindle, characterized in that: It includes a machine body, a shaft core, a pull rod and a driving cylinder. The shaft core is installed on the machine body through a first bearing. The machine body is provided with a stator, the shaft core is provided with a rotor, the shaft core is provided with a center hole extending axially, the pull rod is installed in the center hole, the outer surface of the pull rod is slidably matched with the hole wall of the center hole, the pull rod is provided with an oil storage groove on the outer surface that is slidably matched with the hole wall of the center hole, the pull rod and the shaft core are matched through a notch extending along the axial direction, so that the pull rod rotates synchronously with the shaft core, and the rear end of the pull rod is linked to the piston of the driving cylinder through a second bearing.

2. The telescopic electric spindle according to claim 1, characterized in that: The oil storage groove is formed on the outer surface of the pull rod by using a scraping process.

3. The telescopic electric spindle according to claim 1, characterized in that: The rear end of the shaft core is provided with a shaft end pressure cover, the shaft end pressure cover is provided with a guide hole for the pull rod to pass through, the shaft end pressure cover is provided with teeth protruding into the guide hole, the pull rod is provided with a notch extending along the axial direction, the teeth cooperate with the notch, so that the pull rod rotates synchronously with the shaft core.

4. The telescopic electric spindle according to claim 1, characterized in that: The piston of the driving cylinder is connected to the bearing seat, the inner ring of the second bearing is locked to the pull rod by a first locking nut, and the outer ring of the second bearing is locked to the bearing seat by an outer ring pressure cover. The driving cylinder includes a primary cylinder body, a secondary cylinder body and a tertiary cylinder body. The primary cylinder body is provided with a primary piston, the secondary cylinder body is provided with a secondary piston, the bearing seat is arranged in the tertiary cylinder body, the primary piston acts on the secondary piston, and the secondary piston acts on the bearing seat.

5. The telescopic electric spindle according to claim 4, characterized in that: A pressure sensor for cooperating with the bearing seat is provided in front of the bearing seat along the driving direction of the driving cylinder.

6. The telescopic electric spindle according to claim 1, characterized in that: The shaft core is provided with a first mounting groove, a second mounting groove and a third mounting groove in sequence along the direction in which the pull rod extends outward at the front end of the center hole. The first mounting groove is provided with an O-ring that cooperates with the pull rod, the second mounting groove is provided with a skeleton oil seal that cooperates with the pull rod, and the third mounting groove is provided with an elastic retaining ring.

7. The telescopic electric spindle according to claim 1, characterized in that: A front cover is provided at the front end of the machine body, a second locking nut is provided at the front end of the shaft core, and the front cover and the second locking nut are clearance-matched to form a labyrinth sealing structure.

8. The telescopic electric spindle according to claim 7, characterized in that: An air sealing ring is provided between the front cover of the body and the second locking nut. The air sealing ring is provided with an annular groove on the outer peripheral surface on the side facing the front cover of the body. The air sealing ring is tightly fitted with the front cover of the body, and the air sealing ring is loosely matched with the second locking nut. A plurality of air holes connected to the labyrinth sealing structure are provided along the circumference of the annular groove.

9. The telescopic electric spindle according to claim 1, characterized in that: The stator is installed in the inner hole of the body, a spiral water groove is arranged on the outer circle of the body, a sleeve is arranged on the outer side of the body, the sleeve seals the spiral water groove, and a water inlet and outlet joint is arranged at the rear end of the body.

10. A machine tool, characterized in that: The invention comprises the telescopic electric spindle according to any one of claims 1 to 9.

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