A coaxial gearbox for CNC machine tools

Abstract

The present invention discloses a coaxial gearbox for a numerically controlled machine tool, which relates to the technical field of gearboxes. The coaxial gearbox includes a main housing, a speed-increasing gear set, a speed-reducing gear set, an output shaft, and a drive shaft. The output shaft is provided with a piston channel corresponding to the drive shaft and a hydraulic channel for communicating with an external hydraulic drive mechanism. One end of the drive shaft is inserted into the piston channel to form a hydraulic space for hydraulic drive, and the hydraulic channel is connected to the hydraulic space. The drive shaft is provided with a speed-increasing drive gear for driving the speed-increasing gear set and a speed-reducing drive gear for driving the speed-reducing gear set. On the output shaft, a drive groove and an avoidance groove are provided between the first drive position and the second drive position. By adopting the present invention, the gearbox can be conveniently switched to increase or decrease the rotational output, and the gearbox is small in size and easy to dock and install.

Description

Technical Field

[0001] The present invention relates to the technical field of gearboxes, and in particular to a coaxial gearbox for a numerically controlled machine tool. Background Art

[0002] Based on existing machining processes, the driving sources are mostly high-speed motors, so existing gearboxes are generally reduction gearboxes. For relatively low-speed driving sources such as fuel engines, the gearboxes are mostly speed-increasing gearboxes. Therefore, existing gearboxes are basically single speed-increasing or speed-reducing systems. In this case, to meet the current market demand for complex processing and a wide range of product categories, the driving sources of existing machining machine tools need to be equipped with additional speed-changing systems to expand the processing range of the machine tools. This leads to the need for the structural design of the machine tools to achieve powerful two-way (increase / decrease) speed regulation, which often requires the combination of multiple independent systems. This leads to a sharp increase in the size, weight, and cost of the mechanical equipment, and a decrease in efficiency. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a coaxial gearbox for CNC machine tools, which can conveniently switch the gearbox to increase or decrease the rotational output, and the gearbox is small in size and easy to dock and install.

[0004] To solve the above technical problems, the present invention provides a coaxial gearbox for a CNC machine tool, comprising a main housing, an output shaft, a drive shaft, a speed-increasing gear set for increasing the speed of the output shaft, and a speed-reducing gear set for reducing the speed of the output shaft. The output shaft is provided with a piston passage corresponding to the drive shaft and a hydraulic passage for communicating with an external hydraulic drive mechanism. One end of the drive shaft is inserted into the piston passage to form a hydraulic space for hydraulic drive. The hydraulic passage is in communication with the hydraulic space to control the movement of the drive shaft along the piston passage.

[0005] Wherein, the driving shaft is provided with a speed-increasing driving gear for driving the speed-increasing gear set and a speed-reducing driving gear for driving the speed-reducing gear set;

[0006] When the drive shaft is inserted into the first driving position of the piston channel, the speed reduction drive gear is in contact and meshed with the speed reduction gear set to drive the output shaft to rotate;

[0007] When the drive shaft is inserted into the second driving position of the piston channel, the speed-increasing drive gear is in contact and meshing with the speed-increasing gear set to drive the output shaft to rotate;

[0008] On the output shaft, a driving groove and an avoidance groove are provided between the first driving position and the second driving position, and the driving shaft is provided with a driving block for inserting into the driving groove, so as to drive the output shaft to rotate through the driving block;

[0009] The avoidance groove is provided with an avoidance space for the driving block to rotate;

[0010] When the driving block is inserted into the driving slot, the speed-increasing driving gear and the speed-reducing driving gear are not engaged with the speed-increasing gear set and the speed-reducing gear set.

[0011] As an improvement to the above solution, the transmission ratio of the speed-increasing gear set is less than 1, and the transmission ratio of the speed-reducing gear set is greater than 1.

[0012] As an improvement of the above-mentioned scheme, the speed-increasing gear set includes a speed-increasing access gear for engaging with the speed-increasing drive gear, a speed-increasing linkage gear shaft and a speed-increasing output gear arranged on the output shaft, and a first speed-increasing transition gear and a second speed-increasing transition gear are respectively provided at both ends of the speed-increasing linkage gear shaft to engage with the speed-increasing access gear and the speed-increasing output gear respectively.

[0013] As an improvement to the above-mentioned scheme, the deceleration gear set includes a deceleration access gear for engaging with the deceleration drive gear, a deceleration linkage gear shaft and a deceleration output gear arranged on the output shaft, and the two ends of the deceleration linkage gear shaft are respectively provided with a first deceleration transition gear and a second deceleration transition gear to engage with the deceleration access gear and the deceleration output gear respectively.

[0014] As an improvement to the above solution, a bearing frame for stabilizing the rotation of the output shaft is provided in the main housing, and the bearing frame is provided with a first bearing, on which one end of the output shaft is mounted.

[0015] As an improvement to the above solution, driving rotation ports are respectively provided on both sides of the bearing frame for installing the speed-increasing access gear and the speed-down access gear respectively;

[0016] The driving rotating port is provided with a gear mounting shaft for mounting the speed increasing access gear or the speed decreasing access gear.

[0017] As an improvement to the above solution, along the direction in which the drive shaft is inserted into the piston channel, the piston channel is sequentially provided with the first drive position, the drive groove, the avoidance groove, and the second drive position;

[0018] When the driving shaft is in the second driving position, the driving block is located in the avoidance groove.

[0019] As an improvement to the above solution, along the direction in which the drive shaft is inserted into the piston channel, the drive shaft is sequentially provided with the speed reduction drive gear and the speed increase drive gear;

[0020] The diameter of the speed reduction driving gear is smaller than the diameter of the speed increase driving gear.

[0021] As an improvement to the above-mentioned solution, in the direction in which the drive shaft is inserted into the piston channel, a speed change stroke with a preset spacing is left between the speed increase access gear and the speed decrease access gear, so that the speed change stroke starts at the position where the speed decrease drive gear is meshed with the speed decrease access gear, and ends at the position where the speed increase drive gear is meshed with the speed increase access gear.

[0022] As an improvement to the above solution, it further includes a hydraulic pump, the main box body is provided with a connecting hole connected to the hydraulic channel, the bottom of the main box body is provided with an oil return hole, and the side wall of the main box body is provided with a spray port for spraying the gears, and the hydraulic pump is connected to the connecting hole, the oil return hole and the spray port respectively;

[0023] The hydraulic pump can suck the required lubricating oil in the main box through the oil return hole, and when the drive shaft needs to be driven, the oil supply and discharge in the hydraulic space can be completed through the spray port and the connecting hole.

[0024] The implementation of the present invention has the following beneficial effects:

[0025] The present invention discloses a coaxial gearbox for a CNC machine tool. The coaxial design of the drive shaft and the output shaft can improve the breadth or convenience of usage scenarios and avoid the inconvenience caused by the existing conventional design in which the output shaft and the drive shaft are at right angles.

[0026] Moreover, one end of the drive shaft is inserted into the piston channel to form a hydraulic space for hydraulic drive. The drive shaft can be hydraulically controlled by utilizing the hydraulic space, so that the drive shaft can select the required speed-increasing gear set or speed-reducing gear set to change the speed of the output shaft.

[0027] At the same time, the drive shaft is provided with a drive block for inserting into the drive slot, so that the output shaft is driven to rotate by the drive block, and direct drive between the output shaft and the drive shaft can be realized. Therefore, the coaxial gearbox can realize three driving modes of speed increase, speed decrease or constant speed, and the switching is convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the three-dimensional structure of the coaxial gearbox of the present invention;

[0029] Figure 2 It is a schematic cross-sectional view of the coaxial gearbox of the present invention;

[0030] Figure 3 It is a structural diagram of the docking shaft. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below with reference to the accompanying drawings.

[0032] See also Figure 1 、 2 The present invention provides a coaxial gearbox for a CNC machine tool, comprising a main housing 1, an output shaft 2, a drive shaft 3, a speed-increasing gear set for increasing the speed of the output shaft, and a speed-reducing gear set for reducing the speed of the output shaft. The output shaft 2 is provided with a piston channel 21 corresponding to the drive shaft 3 and a hydraulic channel 22 for communicating with an external hydraulic drive mechanism. One end of the drive shaft 3 is inserted into the piston channel 21 to form a hydraulic space 2a for hydraulic drive. The hydraulic channel 22 is communicated with the hydraulic space 2a to control the movement of the drive shaft 3 along the piston channel 21. The main housing 1 is provided with an output hole for mounting the output shaft and a drive hole for mounting the drive shaft.

[0033] The driving shaft 3 is provided with a speed-increasing driving gear 31 for driving the speed-increasing gear set and a speed-reducing driving gear 32 for driving the speed-reducing gear set;

[0034] When the drive shaft 3 is inserted into the first driving position of the piston channel 21, the speed reduction drive gear 32 is in contact with and meshes with the speed reduction gear set to drive the output shaft 2 to rotate;

[0035] When the drive shaft 3 is inserted into the second driving position of the piston channel 21, the speed-increasing drive gear 31 is in contact and engaged with the speed-increasing gear set to drive the output shaft 2 to rotate;

[0036] On the output shaft 2, a driving groove 23 and an avoidance groove 24 are provided between the first driving position and the second driving position. The driving shaft 3 is provided with a driving block 33 for inserting into the driving groove 23, so as to drive the output shaft 2 to rotate through the driving block 33;

[0037] The avoidance groove 24 is provided with an avoidance space for the driving block 33 to rotate;

[0038] When the driving block 33 is inserted into the driving slot 23 , the speed-increasing driving gear 31 and the speed-reducing driving gear 32 are not engaged with the speed-increasing gear set and the speed-reducing gear set.

[0039] Specifically, the transmission ratio of the speed-increasing gear set is less than 1, and the transmission ratio of the speed-reducing gear set is greater than 1, so as to respectively realize the function of the speed-increasing gear set to increase the output speed of the output shaft 2 and the function of the speed-reducing gear set to reduce the output speed of the output shaft 2.

[0040] In detail, the speed-increasing gear set includes a speed-increasing access gear 41 for engaging with the speed-increasing drive gear 31, a speed-increasing linkage gear shaft 42, and a speed-increasing output gear 44 provided on the output shaft 2. The two ends of the speed-increasing linkage gear shaft 42 are respectively provided with a first speed-increasing transition gear 421 and a second speed-increasing transition gear 422 to engage with the speed-increasing access gear 41 and the speed-increasing output gear 44, respectively. Therefore, the final transmission ratio between the drive shaft 3 and the output shaft 2 can be adjusted by designing the gear ratio between the first speed-increasing transition gear 421 and the second speed-increasing transition gear 422.

[0041] Accordingly, the deceleration gear set includes a deceleration access gear 51 for meshing with the deceleration drive gear 32, a deceleration linkage gear shaft 52, and a deceleration output gear 34 provided on the output shaft 2. A first deceleration transition gear 521 and a second deceleration transition gear 522 are provided at both ends of the deceleration linkage gear shaft 52, respectively, to mesh with the deceleration access gear 51 and the deceleration output gear 34. Therefore, the final drive ratio between the drive shaft 3 and the output shaft 2 can be adjusted by designing the gear ratio between the first deceleration transition gear 521 and the second deceleration transition gear 522.

[0042] In order to stabilize the rotation of the output shaft 2 , a bearing frame 6 for stabilizing the rotation of the output shaft 2 is provided in the main housing 1 . The bearing frame 6 is provided with a first bearing 61 , and one end of the output shaft 2 is mounted on the first bearing 61 .

[0043] The bearing frame 6 is provided with a driving rotation opening 62 on both sides thereof, for installing the speed increasing access gear 41 and the speed decreasing access gear 51 respectively;

[0044] The driving rotation port 62 is provided with a gear mounting shaft 63 for mounting the speed-increasing access gear 41 or the speed-down access gear 51. More preferably, in order to further increase the transmission ratio between the speed-down access gear 51 and the second speed-down transition gear 522, the gear mounting shaft 63 on which the speed-down access gear 51 is mounted is provided with a speed-down auxiliary access gear 53. The gear ratio between the speed-down access gear 51 and the speed-down auxiliary access gear 53 is greater than 1. Accordingly, the speed-down auxiliary access gear 53 meshes with the second speed-down transition gear 522, replacing the speed-down access gear 51 and directly meshing with the second speed-down transition gear 522.

[0045] Similarly, in order to further reduce the transmission ratio between the speed-increasing access gear 41 and the second speed-increasing transition gear 422, the gear mounting shaft 63 on which the speed-increasing access gear 41 is installed is provided with a speed-increasing auxiliary access gear 43, and the gear ratio between the speed-increasing access gear 41 and the speed-increasing auxiliary access gear 43 is less than 1. Accordingly, the speed-increasing auxiliary access gear 43 is engaged with the second speed-increasing transition gear 422 to replace the speed-increasing access gear 41 and directly engage with the second speed-increasing transition gear 422.

[0046] Along the direction of insertion of the drive shaft 3 into the piston channel, the piston channel is sequentially provided with the first drive position, the drive slot 23, the avoidance slot 24, and the second drive position. When the drive shaft 3 is in the second drive position, the drive block 33 is located within the avoidance slot 24. This configuration allows the output shaft 2 to transition from a speed-up state to a synchronization state, and finally to a speed-down state, during the insertion of the drive shaft 3 into the piston channel 21. Accordingly, along the direction of insertion of the drive shaft 3 into the piston channel 21, the drive shaft 3 is sequentially provided with the speed-down drive gear 32 and the speed-up drive gear 31. The diameter of the speed-down drive gear 32 is smaller than that of the speed-up drive gear 31.

[0047] The provision of the avoidance groove 24 allows the drive block 33 to disengage from the drive groove 23 and enter the avoidance groove 24 for idling before the output shaft 2 enters the deceleration state, thereby preventing the drive block 33 and the second deceleration transition gear 522 from simultaneously driving the output shaft 2. Preferably, the avoidance groove 24 is further provided with a second bearing 241, and the drive shaft 3 is adapted to pass through the second bearing 241, thereby reducing friction between the drive shaft 3 and the piston passage 21 and the sidewalls of the hydraulic space 2a.

[0048] In the direction in which the drive shaft 3 is inserted into the piston channel 21, a speed change stroke with a preset spacing is left between the speed increase access gear 41 and the speed decrease access gear 51; the speed change stroke starts at the position where the speed decrease drive gear 32 is meshed with the speed decrease access gear 51, and ends at the position where the speed increase drive gear 31 is meshed with the speed increase access gear 41.

[0049] Preferably, the speed-increasing access gear 41 and the speed-increasing drive gear 31 are both bevel gears, and the speed-increasing access gear 51 and the speed-increasing drive gear 32 are both bevel gears. Furthermore, the tooth surface of the speed-increasing access gear 41 is tilted downward to limit the maximum insertion stroke of the drive shaft 3 into the piston passage 21, thereby facilitating a design in which the speed change stroke terminates at the meshing position between the speed-increasing drive gear 31 and the speed-increasing access gear 41.

[0050] Similarly, the tooth surface of the speed reduction access gear 51 is tilted upward to define the minimum insertion stroke of the drive shaft 3 into the piston passage 21. This facilitates a design in which the speed change stroke begins at the point where the speed reduction drive gear 32 meshes with the speed reduction access gear 51. Furthermore, this also reduces the precision requirements for the hydraulic control that drives the drive shaft 3.

[0051] For the hydraulic drive control of the drive shaft 3, the coaxial transmission further includes a hydraulic pump 7. The main housing 1 is provided with a connecting hole 11 communicating with the hydraulic passage 22, an oil return hole 12 at the bottom of the main housing 1, and a spray port 13 for spraying the gears. The hydraulic pump 7 is connected to the connecting hole 11, the oil return hole 12, and the spray port 13, respectively, so that the hydraulic pump 7 can draw the required lubricating oil from the main housing 1 through the oil return hole 12. When it is necessary to drive the drive shaft 3, the hydraulic pump 7 can complete the oil supply and discharge of the hydraulic space 2a through the spray port 13 and the connecting hole 11. When the hydraulic pump 7 is in the oil discharge state, the oil volume in the hydraulic space 2a decreases, and the drive shaft continues to be driven into the hydraulic space 2a. Similarly, when the hydraulic pump 7 is in the oil supply state, the oil volume in the hydraulic space 2a increases, driving the drive shaft away from the hydraulic space 2a.

[0052] Preferably, the communicating channel 22 is T-shaped, and the output shaft is provided with an annular groove 221 communicating with the communicating channel 22, and the annular groove 221 corresponds to the communicating hole 11, so that the communicating channel 22 and the communicating hole 11 are maintained in a communicating state when the output shaft rotates.

[0053] In order to facilitate the transmission between the drive shaft 3 and the external rotating drive component, the main housing 1 is provided with a docking shaft 8, and the main housing 1 is correspondingly provided with a third bearing 14 for mounting the docking shaft. One end of the docking shaft 8 is provided with a docking hole 81 for inserting the drive shaft 3. The inner side wall of the docking hole 81 is provided with a docking stroke groove 82 for driving the drive shaft 3 to rotate. The drive shaft 3 is provided with a drive key 35 adapted to the docking stroke groove 82, so that when the drive shaft 3 moves along the piston channel 21, the drive key 35 moves in the docking stroke groove 82 along the axial direction of the drive shaft 3. Correspondingly, the other end of the docking shaft 8 is provided with an output access hole 83 for receiving the output shaft of the power supply motor. The output access hole 83 is correspondingly provided with a keyway 84, and the motor output shaft is correspondingly provided with an adapted output drive key to drive the rotation of the docking shaft.

[0054] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A coaxial gearbox for a CNC machine tool, characterized in that: The hydraulic transmission comprises a main housing, an output shaft and a drive shaft, a speed-increasing gear set for increasing the speed of the output shaft, and a speed-reducing gear set for reducing the speed of the output shaft. The output shaft is provided with a piston channel corresponding to the drive shaft and a hydraulic channel for communicating with an external hydraulic drive mechanism. One end of the drive shaft is inserted into the piston channel to form a hydraulic space for hydraulic drive. The hydraulic channel is in communication with the hydraulic space to control the movement of the drive shaft along the piston channel. Wherein, the driving shaft is provided with a speed-increasing driving gear for driving the speed-increasing gear set and a speed-reducing driving gear for driving the speed-reducing gear set; When the drive shaft is inserted into the first driving position of the piston channel, the speed reduction drive gear is in contact and meshed with the speed reduction gear set to drive the output shaft to rotate; When the drive shaft is inserted into the second driving position of the piston channel, the speed-increasing drive gear is in contact and meshing with the speed-increasing gear set to drive the output shaft to rotate; On the output shaft, a driving groove and an avoidance groove are provided between the first driving position and the second driving position, and the driving shaft is provided with a driving block for inserting into the driving groove, so as to drive the output shaft to rotate through the driving block; The avoidance groove is provided with an avoidance space for the driving block to rotate; When the driving block is inserted into the driving slot, the speed-increasing driving gear and the speed-reducing driving gear are not engaged with the speed-increasing gear set and the speed-reducing gear set; The speed-increasing gear set includes a speed-increasing access gear for meshing with the speed-increasing drive gear, a speed-increasing linkage gear shaft, and a speed-increasing output gear provided on the output shaft. The two ends of the speed-increasing linkage gear shaft are respectively provided with a first speed-increasing transition gear and a second speed-increasing transition gear to mesh with the speed-increasing access gear and the speed-increasing output gear respectively. The deceleration gear set includes a deceleration access gear for meshing with the deceleration drive gear, a deceleration linkage gear shaft, and a deceleration output gear provided on the output shaft. The two ends of the deceleration linkage gear shaft are respectively provided with a first deceleration transition gear and a second deceleration transition gear to mesh with the deceleration access gear and the deceleration output gear respectively. Along the direction in which the drive shaft is inserted into the piston channel, the piston channel is sequentially provided with the first drive position, the drive groove, the avoidance groove, and the second drive position; When the driving shaft is in the second driving position, the driving block is located in the avoidance groove; Along the direction in which the drive shaft is inserted into the piston channel, the drive shaft is provided with the speed reduction drive gear and the speed increase drive gear in sequence; The diameter of the speed reduction drive gear is smaller than the diameter of the speed increase drive gear; In the direction in which the drive shaft is inserted into the piston channel, a speed change stroke with a preset spacing is left between the speed increase access gear and the speed decrease access gear, so that the speed change stroke starts at the position where the speed decrease drive gear is meshed with the speed decrease access gear, and ends at the position where the speed increase drive gear is meshed with the speed increase access gear.

2. The coaxial gearbox according to claim 1, characterized in that: The transmission ratio of the speed-increasing gear set is less than 1, and the transmission ratio of the speed-reducing gear set is greater than 1.

3. The coaxial gearbox according to claim 1, wherein: A bearing frame for stabilizing the rotation of the output shaft is provided in the main housing. The bearing frame is provided with a first bearing, and one end of the output shaft is mounted on the first bearing.

4. The coaxial gearbox according to claim 3, characterized in that: The bearing frame is provided with a driving rotation opening on both sides for installing the speed-increasing access gear and the speed-down access gear respectively; The driving rotating port is provided with a gear mounting shaft for mounting the speed increasing access gear or the speed decreasing access gear.

5. The coaxial gearbox according to claim 1, wherein: It also includes a hydraulic pump, the main box body is provided with a connecting hole connected to the hydraulic channel, the bottom of the main box body is provided with an oil return hole, the side wall of the main box body is provided with a spray port for spraying the gear, and the hydraulic pump is connected to the connecting hole, the oil return hole and the spray port respectively; The hydraulic pump can suck the required lubricating oil in the main box through the oil return hole, and when driving the drive shaft, it can transport and drain oil in the hydraulic space through the spray port and the connecting hole.

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