Machining center speed change gear box and machine tool

Abstract

The utility model relates to a machining center speed change gear box and a machine tool, which comprise a box body, a power shaft, a spline shaft and a main shaft are rotatably arranged in the box body through bearings, a gear I is fixedly arranged on the power shaft, a gear II meshed with the gear I is fixedly arranged on the spline shaft, and a gear III is sleeved on the spline shaft. A gear III is fixedly mounted on a hub of the spline shaft, a gear IV is fixedly mounted on a hub of the gear III, a pushing assembly for pushing the gear III and the gear IV to move together in the axis direction of the spline shaft to achieve speed change is arranged on the box body, and due to the fact that the gear III and the gear IV are independently designed and assembled, if one gear needs to be maintained or replaced, the gear III and the gear IV can be replaced. And only the damaged gear needs to be replaced independently. Therefore, compared with the mode that a duplicate gear is installed on the spline shaft, the mode that the gear III and the gear IV are installed on the spline shaft is lower in maintenance cost.

Description

Technical Field

[0001] The utility model relates to the technical field of machine tools, in particular to a speed change gear box for a machining center and a machine tool. Background Art

[0002] A gearbox is a power transmission mechanism that uses gear ratios to reduce the speed of a motor to the desired speed and generate high torque. Gearboxes are widely used in current mechanisms for transmitting power and motion, ranging from high-power transmission to small loads and precise angular transmission. Furthermore, in industrial applications, gearboxes can both reduce speed and increase torque. Large machine tools, such as CNC gantry milling machines and planing, boring, and milling machines, often use gearboxes to reduce speed and increase spindle torque, thereby achieving cutting force and maintaining constant power output at high speeds. While the gears used for speed change in existing gearboxes are typically integrated, also known as multi-gears, with two or more gear teeth integrally formed on a single hub. This structure offers high efficiency during assembly and production, but subsequent maintenance is often difficult because multi-gears consist of multiple gears that cannot be disassembled without loss of integrity. Damage to a single gear requires replacement of the entire multi-gear system, significantly increasing repair costs.

[0003] For example, a Chinese patent with publication number CN201236932Y discloses a two-stage gearbox for machine tools, which records that the motor is connected to shaft I through a coupling, shaft I is supported by a single-row angular contact ball bearing III and a single-row angular contact ball bearing IV, shaft I is equipped with a gear IV that meshes with gear I installed on shaft II, shaft II is supported by a single-row angular contact ball bearing II and a single-row angular contact ball bearing V, shaft II is equipped with a double gear, the shift fork is driven by a cylinder, shaft III is supported by a single-row angular contact ball bearing I and a double-row angular contact ball bearing, shaft III is equipped with gear II and gear III, each bearing is tightened by a bearing cover, the output end of shaft III is equipped with a synchronous pulley, the synchronous pulley is tightened by an elastic sleeve, and the gearbox is fastened to the machine tool by 8 screws.

[0004] In the above scheme, a double gear is installed on shaft II, and the shift fork is driven by a cylinder to achieve speed change. If one of the gears needs to be replaced or repaired, the entire double gear must be replaced as a whole, which is very expensive to replace. Utility Model Content

[0005] In order to solve the above problems, the utility model provides a speed change gear box for a machining center.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a speed change gearbox for a machining center, comprising a box body, in which a power shaft, a spline shaft and a main shaft are rotatably installed through bearings, a gear I is fixedly installed on the power shaft, a gear II meshing with gear I is fixedly installed on the spline shaft, a gear III is sleeved on the spline shaft, and a gear IV is fixedly installed on the hub of gear III, and a pushing component is provided on the box body to push gear III and gear IV to move together along the axial direction of the spline shaft to achieve speed change.

[0007] Compared to existing technologies, since Gears III and IV are designed and assembled separately, after extended use, if one gear needs repair or replacement, only the damaged gear needs to be replaced. Mounting duplex gears on a spline shaft, on the other hand, requires replacing the entire duplex gear if one gear needs replacement or repair. Therefore, mounting Gears III and IV on a spline shaft results in lower maintenance costs.

[0008] Preferably, retaining springs are provided on both sides of the gear II, and the retaining springs are clamped on the spline shaft.

[0009] Preferably, a lubrication rod is fixedly installed in the box, a through hole is provided in the lubrication rod, and several lubrication tubes connected to the through hole are installed on the side wall of the lubrication rod, one end of the lubrication tube extends to each meshing point and each bearing installation point respectively.

[0010] Compared to existing technologies, each meshing point and bearing mounting point is lubricated using a separate lubrication pipe. Compared to adding large amounts of lubricating oil to the mounting chamber, where the centrifugal force of the rotating components draws the lubricating oil to each component, this solution effectively ensures that every component in the housing receives appropriate lubrication. It also reduces the amount of lubricating oil stored in the mounting chamber.

[0011] Preferably, a stop ring is fixedly mounted on the wheel hub, and gear IV is located between the stop ring and the rim of gear III.

[0012] Preferably, the pushing assembly includes a shift plate rotatably connected to the hub of gear IV; the shift plate is located between the stop ring and the rim of gear IV; a shift fork is provided on the shift plate, and the shift fork and the spline shaft are arranged perpendicular to each other; one end of the shift fork is connected to a push rod arranged parallel to the spline shaft, and the push rod is slidably installed on the box body, and a cylinder fixedly connected to the push rod is fixedly installed on the box body.

[0013] Preferably, the shift plate is provided with corresponding card slots, and the shift fork is provided with a card platform adapted to the card slots.

[0014] Preferably, the main shaft is fixedly mounted with gear V and gear VI. In the normal state, gear IV is meshed with gear V; in the speed change state, gear III is meshed with gear VI.

[0015] Preferably, one end of the spindle is provided with a tapered hole for installing a tool, a core shaft is slidably arranged in the spindle, a cylinder is provided on the box body, the output end of the cylinder is connected to one end of the core shaft; the other end of the core shaft is located in the tapered hole.

[0016] Preferably, an encoder is fixedly mounted on the outer side of the box, a driven wheel is fixedly mounted on the encoder, and a synchronous wheel with the same structure as the driven wheel is fixedly mounted on the end of the main shaft, and the synchronous wheel and the driven wheel are connected by a synchronous belt drive.

[0017] A machine tool comprises any one of the above-mentioned speed change gearboxes for a machining center.

[0018] The beneficial effects of the present invention are described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is an isometric stereogram of the utility model when assembled.

[0020] Figure 2 It is an isometric stereogram of the interior of the utility model.

[0021] Figure 3 It is a cross-sectional view of the utility model.

[0022] Figure 4 It is an enlarged view of point A of the present utility model.

[0023] Explanation of the accompanying numbers: 01. Box, 02. Servo motor, 03. Power shaft, 04. Gear I, 05. Spline shaft, 06. Gear II, 07. Gear III, 08. Gear IV, 09. Stop ring, 10. Shift plate, 11. Shift fork, 12. Push rod, 13. Cylinder, 14. Slot, 15. Card table, 16. Spindle, 17. Encoder, 18. Driven pulley, 19. Synchronous pulley, 20. Lubrication rod, 21. Lubrication tube, 22. Gear V, 23. Gear VI. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0025] See also Figure 1-4As shown, the present invention relates to a speed-changing gearbox for a machining center, comprising a housing 01 attached to the main body of the machining center. Housing 01 includes a mounting chamber. A servo motor 02 is fixedly mounted on the outside of housing 01. A power shaft 03 is fixedly connected to servo motor 02 via a coupling. Both ends of power shaft 03 are mounted within the mounting chamber via bearings, allowing servo motor 02 to drive power shaft 03 to rotate within housing 01. Gear I 04 is fixedly mounted on power shaft 03 via a flat key. Gear I 04 meshes with gear II 06 on a spline shaft 05. Both ends of spline shaft 05 are mounted within the mounting chamber via bearings. When gear I 04 rotates, gear II 06 is driven, in turn, to rotate spline shaft 05 within housing 01. Gear II 06 is provided with retaining springs on both sides, which engage spline shaft 05 to prevent gear II 06 from moving axially along spline shaft 05 during rotation.

[0026] See also Figure 2-4 As shown, spline shaft 05 is fitted with gear III07, located on one side of gear II06. Gear IV08 and a stop ring 09 are fixedly mounted to the hub of gear III07 via a flat key. Gear IV08 is located between the stop ring 09 and the rim of gear III07. A shift plate 10 is rotatably connected to the hub of gear IV08 via a bearing. This prevents shift plate 10 from rotating synchronously with gear IV08. Shift plate 10 is located between the stop ring 09 and the rim of gear IV08. A shift fork 11 is mounted on shift plate 10, positioned perpendicularly to spline shaft 05. One end of shift fork 11 is connected to a push rod 12, which is arranged parallel to spline shaft 05. Push rod 12 is slidably mounted on housing 01, and housing 01 is fixedly mounted with a connecting cylinder 13, which is fixedly connected to push rod 12. When the output end of cylinder 13 extends, it applies a thrust to shift plate 10. The thrust generated by cylinder 13 is applied to gear IV 08 through shift plate 10. The driving assembly composed of push rod 12, cylinder 13, shift plate 10, and shift fork 11 thus drives gears III 07 and IV 08 to move synchronously along the axial direction of spline shaft 05, thereby achieving speed change.

[0027] Compared to existing technologies, since Gear III07 and Gear IV08 are designed and assembled separately, after extended use, if one gear needs repair or replacement, only the damaged gear needs to be replaced. Mounting the duplex gears on spline shaft 05, on the other hand, requires replacing the entire duplex gear if one gear needs replacement or repair. Therefore, mounting Gear III07 and Gear IV08 on spline shaft 05 results in lower maintenance costs than mounting the duplex gears on spline shaft 05.

[0028] The shift plate 10 is relatively provided with a card slot 14, and the shift fork 11 is provided with a card platform 15 adapted to the card slot 14. The arrangement of the card platform 15 and the card slot 14 can further prevent the shift plate 10 from rotating with the gear IV08.

[0029] Main shaft 16 is mounted on housing 01 via either an air static pressure bearing or a liquid pressure bearing, ensuring smooth, vibration-free rotation and improved rotational accuracy. Gear V22 and Gear VI23 are secured to main shaft 16 via a key. The transmission ratio between Gear IV08 and Gear V22 is 1:1.1, while the transmission ratio between Gear III07 and Gear VI23 is 1:4.5. Normally, the output end of cylinder 13 is retracted, meshing with Gear IV08 and Gear V22 to drive main shaft 16. To change the speed of main shaft 16, the output end of cylinder 13 extends, pushing Gear III07 and Gear IV08 together along the axis of spline shaft 05, meshing Gear III07 with Gear VI23 and thus achieving the main shaft speed change.

[0030] One end of the spindle 16 is provided with a tapered hole for installing a tool. A mandrel is housed within the spindle 16, one end of which is fixedly connected to the output end of the cylinder 13. The other end is located within the tapered hole. To replace a tool, the output end of the cylinder 13 extends, placing one end of the mandrel against the tool in the tapered hole, applying thrust and making it easier to remove from the hole. To install the tool, the output end of the cylinder 13 retracts, separating the mandrel from the tool without interfering with its installation.

[0031] See also Figure 2 As shown, an encoder 17 is fixedly mounted on the outside of the housing 01, and a driven pulley 18 is fixedly mounted on the encoder 17. A synchronous pulley 19 with the same structure as the driven pulley 18 is fixedly mounted on the end of the main shaft 16. The synchronous pulley 19 and the driven pulley 18 are connected by a synchronous belt drive. When the main shaft 16 rotates, the synchronous pulley 19 is driven by the rotation of the main shaft 16, and the speed of the main shaft 16 is converted into an electrical signal by the encoder 17, which facilitates the precise control of the speed of the main shaft 16.

[0032] See also Figure 2As shown, a lubrication rod 20 is fixedly mounted within housing 01, parallel to the main shaft 16. One end of the lubrication rod 20 extends into the mounting chamber. A through-hole is provided within the lubrication rod 20, and several lubrication tubes 21 are installed on the sidewalls of the lubrication rod 20, connected to the through-hole. One end of the lubrication tubes 21 extends to each meshing point and each bearing mounting point. An oil pump is installed outside housing 01 to deliver lubricating oil at the bottom of the mounting chamber or lubricating oil outside housing 01 into the lubrication rod 20. The lubricating oil is then delivered through the lubrication tubes 21 to the meshing points of gears I 04 and II 06, the meshing points of gears IV 08 and V, the meshing points of gears III 07 and VI, as well as the bearing mounting points between the power shaft 03 and housing 01, the bearing mounting points between the spline shaft 05 and housing 01, and the bearing mounting points between the shift plate 10 and the hub of gear III 07 for lubrication. Compared to the prior art, each meshing point and bearing mounting point is lubricated using a separate lubrication pipe 21. Compared to adding a large amount of lubricating oil to the mounting chamber, this solution effectively ensures that every component within the housing 01 receives appropriate lubrication due to the centrifugal force of the rotating components. It also reduces the amount of lubricating oil stored in the mounting chamber.

[0033] It should be noted that, for the sake of clarity, the “cylinders” installed in different positions are marked with the same reference numeral “13”.

[0034] During operation, servo motor 02 drives gear I04 on power shaft 03 to rotate, thereby driving spline shaft 05 to rotate within housing 01. Gear IV08 and gear V22 on spline shaft 05 rotate, driving the main shaft to rotate. Simultaneously, cylinder 13 drives gears III07 and IV08 to move on spline shaft 05, meshing gear III07 with gear VI23 to achieve speed change for the main shaft. Simultaneously, when servo motor 02 is activated, lubrication pipe 21 delivers lubricating oil to each meshing point and bearing mounting area for lubrication.

[0035] The present application also relates to a machine tool comprising the above-mentioned machining center speed change gearbox.

[0036] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "two ends", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0038] The above embodiments are merely descriptions of preferred embodiments of the present invention and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary engineering technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A speed change gearbox for a machining center, comprising a housing, in which a power shaft, a spline shaft, and a main shaft are rotatably mounted via bearings, a gear I is fixedly mounted on the power shaft, and a gear II is fixedly mounted on the spline shaft and meshes with the gear I, characterized in that: The gear III is sleeved on the spline shaft, and the gear IV is fixedly installed on the hub of the gear III by means of a flat key. The housing is provided with a pushing assembly for pushing gear III and gear IV to move along the axial direction of the spline shaft to achieve speed change. Circlips are provided on both sides of the gear II, and the circlips are clamped on the spline shaft. A stop ring is fixedly installed on the hub of the gear III by means of a flat key. The gear IV is located between the stop ring and the rim of the gear III. The pushing assembly includes a shift plate rotatably connected to the hub of the gear IV; the shift plate is located between the stop ring and the rim of the gear IV; a shift fork is provided on the shift plate, and the shift fork and the spline shaft are arranged perpendicular to each other; one end of the shift fork is connected to a push rod arranged parallel to the spline shaft, and the push rod is slidably installed on the housing, and a cylinder fixedly connected to the push rod is fixedly installed on the housing.

2. The speed change gearbox for a machining center according to claim 1, characterized in that: A lubrication rod is fixedly installed in the box body, a through hole is provided in the lubrication rod, and a plurality of lubrication tubes connected with the through hole are installed on the side wall of the lubrication rod, one end of the lubrication tube extends to each meshing part and each bearing installation part respectively.

3. The speed change gearbox for a machining center according to claim 1, characterized in that: The shift plate is provided with card slots opposite to each other, and the shift fork is provided with a card platform adapted to the card slots.

4. The speed change gearbox for a machining center according to claim 1, characterized in that: The main shaft is fixedly mounted with gear V and gear VI. In a normal state, gear IV is meshed with gear V; in a speed change state, gear III is meshed with gear VI.

5. The speed change gearbox for a machining center according to claim 4, characterized in that: One end of the main shaft is provided with a tapered hole for installing a tool, a core shaft is slidably arranged in the main shaft, a cylinder is provided on the box body, the output end of the cylinder is connected to one end of the core shaft; the other end of the core shaft is located in the tapered hole.

6. The speed change gearbox for a machining center according to claim 5, characterized in that: An encoder is fixedly installed on the outside of the box, a driven wheel is fixedly installed on the encoder, and a synchronous wheel with the same structure as the driven wheel is fixedly installed on the end of the main shaft. The synchronous wheel and the driven wheel are connected by a synchronous belt drive.

7. A machine tool, characterized in that: A machining center speed change gearbox comprising the speed change gearbox according to any one of claims 1 to 6.

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