Grinding machine integrating external thread grinding and tooth profile grinding

Abstract

The invention provides an external thread and tooth profile grinding integrated grinding machine which is used for machining a planetary roller and comprises a machine body, a two-axis module, a turret device, a first grinding wheel assembly and a second grinding wheel assembly. A planetary roller is installed between a workpiece headstock and a tailstock of the lathe bed, and the axis of the planetary roller is parallel to the Z axis of the two-axis module. The turret device enables the first grinding wheel assembly to work, the first motorized spindle drives the first grinding wheel to rotate, the two-axis module drives the first grinding wheel to move on the Z axis and the X axis, and the first grinding wheel grinds threads of the planetary roller in combination with autorotation of the planetary roller. The turret device switches the second grinding wheel assembly to work, the second electric spindle drives the second grinding wheel to rotate, the two-axis module drives the second grinding wheel to move on the Z axis and the X axis, the second grinding wheel grinds the gear on one side of the planetary roller, and ground teeth in the gear are replaced by combining rotation of the planetary roller. And after all teeth on one side of the planetary roller are ground, the gear on one side of the planetary roller is ground by the grinding wheel II.

Description

Technical Field

[0001] This application relates to grinding machines, and more particularly to a grinding machine that integrates external thread and tooth profile grinding. Background Technology

[0002] A planetary roller screw is a precision transmission device, typically composed of a screw, a nut, and planetary rollers. Multiple planetary rollers are arranged in a circular array on the cage of the nut, with the screw located within this circle of planetary rollers. For any given planetary roller, the central section is the external thread segment, and the two side sections are gear segments. The external thread and the inner side mesh with the screw, while the outer side meshes with the internal thread of the nut. The gears mesh with the internal gear ring of the nut. After machining, the planetary rollers require grinding of both the external thread and the gears to ensure their precision.

[0003] Currently, horizontal gear grinding machines are generally used to grind gears, while external thread grinding machines are used to grind external threads. This method of processing external threads and gears separately using two different grinding machines introduces factors such as secondary clamping of planetary rollers and positioning deviations. These factors result in inconsistent thread entry angles and gear normal angles among the planetary rollers, and inconsistent phases among all planetary rollers in the same planetary roller screw set. This leads to the following problems: 1. Inconvenient assembly of the planetary roller screw, affecting the reusability of planetary roller assembly; 2. Affecting the meshing coordination between multiple planetary rollers during the movement of the planetary roller screw. Application content

[0004] This application provides a grinding machine that integrates external thread and tooth profile grinding, which can solve the problems mentioned in the background art.

[0005] This application provides a grinding machine that integrates external thread and tooth profile grinding, comprising: The bed is equipped with a workpiece headstock and a tailstock that are opposite each other on the Z-axis; The two-axis module is connected to the bed and has linear motion in the Z and X axes; The turret assembly has its stationary plate fixedly connected to the mounting platform of the two-axis module. The first grinding wheel assembly includes: a grinding wheel frame connected to the moving disc part of the turret device, an electric spindle connected to the grinding wheel frame, and a grinding wheel mounted on the electric spindle; the grinding wheel is used for grinding external threads. The second grinding wheel assembly includes: a second grinding wheel frame connected to the moving disc part of the turret device, a second electric spindle connected to the second grinding wheel frame, and a second grinding wheel mounted on the second electric spindle; the second grinding wheel is used for grinding tooth profiles.

[0006] In some embodiments, the turntable of the headstock has a first tip and a clamp; the tailstock has a second tip; the clamp is used to hold the end of the workpiece and connect the workpiece and the turntable.

[0007] In some embodiments, the clamp includes: a connecting block that can be radially slidably fixed to the turntable, a first clamping block connected to the connecting block, a second clamping block, and a fastener disposed between the first clamping block and the second clamping block.

[0008] In some embodiments, the moving disc portion is provided with a grinding wheel holder oscillation mechanism that acts on the grinding wheel holder.

[0009] In some embodiments, the connection positions of the first grinding wheel holder in the moving disc portion and the connection positions of the second grinding wheel holder in the moving disc portion are opposite to each other.

[0010] In some embodiments, at least one of the following configurations is also included: Configuration 1: further includes a grinding wheel dresser 1, with the grinding wheel dresser 1 matched with a grinding wheel 1; Configuration 2: further includes a grinding wheel dresser 2, with the grinding wheel dresser 2 matched with a grinding wheel 2.

[0011] In some embodiments, a first grinding wheel dresser is disposed on the workpiece headstock; a second grinding wheel dresser is disposed on the bed on the side of the tailstock away from the workpiece headstock.

[0012] In summary, this application provides a grinding machine that integrates external thread and tooth profile grinding for machining planetary rollers. It includes a bed, a two-axis module, a turret assembly, a first grinding wheel assembly, and a second grinding wheel assembly. The planetary rollers are mounted between the workpiece headstock and tailstock of the bed, with the axis of the planetary rollers parallel to the Z-axis of the two-axis module. The turret assembly operates the first grinding wheel assembly; the electric spindle drives the first grinding wheel to rotate, and the two-axis module drives the first grinding wheel to move along the Z and X axes. Combined with the rotation of the planetary rollers, the first grinding wheel grinds the threads of the planetary rollers. The turret assembly then switches to operate the second grinding wheel assembly; the electric spindle drives the second grinding wheel to rotate, and the two-axis module drives the second grinding wheel to move along the Z and X axes. The second grinding wheel grinds the gears on one side of the planetary rollers, and the rotation of the planetary rollers changes the teeth being ground. After all teeth on one side of the planetary rollers are ground, the second grinding wheel grinds the gears on the same side. The beneficial effects include: easier unification of thread inlet angle and gear normal angle in planetary rollers; improved phase consistency and accuracy of all planetary rollers in the same set of planetary roller screws; easier assembly of planetary roller screws; and better coordination and repeatable assembly of planetary roller meshing. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application or the background art will be described below.

[0014] Figure 1 This is a schematic diagram of planetary rollers; Figure 2 This is a schematic diagram of the present application; Figure 3 for Figure 2 An enlarged schematic diagram of part A in the middle; Figure 4 Schematic diagram of turret assembly, grinding wheel assembly one, and grinding wheel assembly two; Figure 5 A schematic diagram of the turntable and clamps; Figure 6 for Figure 5 Enlarged schematic diagram of part B.

[0015] In the picture, 1. Bed; 1A. Workpiece headstock; 1A1. Turntable; 1A2. Center 1; 1B. Tailstock; 1B1. Center 2; 2. Two-axis module; 3. Turret assembly; 31. Stationary disc section; 32. Moving disc section; 33. Grinding wheel frame oscillation mechanism; 4. First grinding wheel assembly; 41. Grinding wheel head 1; 42. Electric spindle 1; 43. Grinding wheel 1; 5. Second grinding wheel assembly; 51. Grinding wheel head two; 52. Electric spindle two; 53. Grinding wheel two; 6. Grinding wheel dresser one; 7. Grinding wheel dresser II; 8. Fixture; 81. Connecting block; 82. Clamping block one; 83. Clamping block two; 84. Fastener; 85. Connecting pin; 9. Planetary rollers; 9A. External threads; 9B. Gears. Specific Implementation

[0016] The following description, in conjunction with the accompanying drawings, is provided for illustrative purposes only and is not strictly to scale. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components; terms such as "comprising" or "including" mean that the element or object preceding the term encompasses the element or object listed following the term and its equivalents, without excluding other elements or objects; terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect; terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. Unless otherwise specified, the embodiments in this application can be combined with each other.

[0017] Please see Figure 1 and Figure 2A grinding machine that integrates external thread and tooth profile grinding for machining planetary rollers 9, comprising a bed 1, a two-axis module 2, a turret device 3, a first grinding wheel assembly 4, and a second grinding wheel assembly 5.

[0018] The bed 1 is provided with a workpiece headstock 1A and a tailstock 1B, which are opposite each other on the Z-axis. The planetary rollers 9 are installed between the workpiece headstock 1A and the tailstock 1B. Referring to the tailstock of an existing external thread grinding machine, in this application, the tailstock 1B can be slidably fixed on the bed 1 along the Z-axis. The planetary rollers 9 are installed by adjusting the fixed position of the tailstock 1B on the bed 1.

[0019] After installation, the axis of the planetary roller 9 needs to be parallel to the Z-axis. Referring to the workpiece headstock of an existing external thread grinding machine, the workpiece headstock 1A in this application has a rotatable turntable 1A1. The rotation of the turntable 1A1 drives the planetary roller 9 installed between the workpiece headstock 1A and the tailstock 1B to rotate.

[0020] Regarding the mounting method of the planetary roller 9 between the workpiece headstock 1A and the tailstock 1B: A chuck (such as a three-jaw chuck) can be used as the turntable 1A1 of the workpiece headstock 1A, and the tailstock 1B has a center point. That is, the planetary rollers 9 are installed in a clamping and centering manner.

[0021] Please see Figure 3 and Figure 6 The turntable 1A1 can have a center 1A2 and a clamp 8, while the tailstock 1B has a center 1B1. The clamp 8 is used to hold the end of the workpiece and connect the workpiece and the turntable 1A1. That is, the planetary rollers 9 are installed in the form of double centers, which, together with the clamp 8, connect the workpiece and the turntable 1A1, so that the turntable 1A1 can drive the workpiece to rotate.

[0022] In some embodiments, the planetary roller 9 is preferably mounted between the workpiece headstock 1A and the tailstock 1B in such a way that the turntable 1A1 has a center point 1A2 and a clamp 8, and the tailstock 1B has a center point 1B1.

[0023] Center holes are machined at both ends of the planetary roller 9, with the two center holes respectively for the entry of center tip 1A2 and center tip 1B1. The machining of the two center holes can meet the corresponding precision requirements, which can better ensure the positional accuracy of the axis of the planetary roller 9 after installation compared to the single clamp and single tip configuration.

[0024] The clamp 8 can be an existing heart-shaped chuck. More specifically, the clamp 8 is a clamping sleeve and a lever is fixedly connected to the outer wall of the clamping sleeve. The clamping sleeve is clamped and fixed to the end of the planetary roller 9, and the lever is inserted into the socket left in the turntable 1A1.

[0025] Please see Figure 5 and Figure 6This application also provides another clamp 8, which includes a connecting block 81, a first clamping block 82, a second clamping block 83, and a fastener 84.

[0026] The connecting block 81 can slide radially and be fixed to the turntable 1A1, that is, the connecting block 81 can slide radially relative to the turntable 1A1. A locking structure is also designed between the connecting block 81 and the turntable 1A1 to restrict the radial sliding. The restricting effect of the locking structure can be released.

[0027] More specifically, referring to a three-jaw chuck, the turntable 1A1 is rotatably connected to an input shaft and a flat threaded disc, with bevel gear transmission between the input shaft and the flat threaded disc, and the connecting block 81 has threads matching the flat threaded disc. The locking structure is a self-locking mechanism between the connecting block 81 and the flat threaded disc.

[0028] Clamping block 82 is connected to connecting block 81. More specifically, a connecting pin 85 may be provided between clamping block 82 and connecting block 81. Both clamping block 82 and clamping block 83 have grooves for fitting the ends of planetary rollers 9.

[0029] Fastener 84 is positioned between clamping block 1 82 and clamping block 2 83: First, install the planetary roller 9 between tip 1A2 and tip 2B1; then adjust the position of connecting block 81 radially so that the groove of clamping block 1 82 fits against the end of the planetary roller 9; then tighten fastener 84 so that the grooves of clamping block 1 82 and clamping block 2 83 abut against the end of the planetary roller 9.

[0030] When the diameter of the planetary roller 9 is changed, the clamping blocks 82 and 83 with matching grooves can be replaced, and the position of the connecting block 81 on the turntable 1A1 can be adjusted radially to make the grooves adapt to the planetary roller 9.

[0031] In some embodiments, the clamp 8 preferably includes the connecting block 81, clamping block one 82, clamping block two 83, and fastener 84 as described above. Compared to a chuck, it can adapt to changes in the diameter of the planetary roller 9 more quickly and conveniently.

[0032] Please see Figure 2 The two-axis module 2 is connected to the bed 1 and has linear motion in the Z and X axes. The Z axis corresponds to the axial direction of the planetary rollers 9; the X axis corresponds to the radial direction of the planetary rollers 9, moving closer to / away from the planetary rollers 9. Referring to the two-axis modules of existing external thread grinding machines, the drive of the two-axis module 2 in this application can be two sets of linear modules in the form of lead screws, driven by servo motors, and combined with grating rulers to form closed-loop control.

[0033] Please see Figure 2 and Figure 4The stationary disc portion 31 of the turret device 3 is fixedly connected to the mounting platform of the two-axis module 2. The moving disc portion 32 of the turret device 3 is used for subsequent installation of the first grinding wheel assembly 4 and the second grinding wheel assembly 5. By rotating the moving disc portion 32 relative to the stationary disc portion 31, the first grinding wheel assembly 4 and the second grinding wheel assembly 5 are switched to process the planetary roller 9. Referring to some existing turret devices, the turret device 3 in this application can adopt a servo motor with a reducer.

[0034] Please see Figure 2 and Figure 4 The first grinding wheel assembly 4 includes a grinding wheel holder 41, an electric spindle 42, and a grinding wheel 43. The grinding wheel holder 41 is connected to the moving disc part 32. The electric spindle 42 is connected to the grinding wheel holder 41. The grinding wheel 43 is mounted on the electric spindle 42, meaning that the grinding wheel 43 is driven to rotate by the electric spindle 42. The grinding wheel 43 is used to grind the external thread 9A at the middle position of the planetary roller 9. The grinding wheel 43 can be selected according to product requirements.

[0035] The second grinding wheel assembly 5 includes a second grinding wheel holder 51, a second electric spindle 52, and a second grinding wheel 53. The second grinding wheel holder 51 is connected to the moving plate part 32. The second electric spindle 52 is connected to the second grinding wheel holder 51. The second grinding wheel 53 is mounted on the second electric spindle 52, meaning that the second grinding wheel 53 is driven to rotate by the second electric spindle 52. The second grinding wheel 53 is used to grind the gears 9B on both sides of the planetary rollers 9. The second grinding wheel 53 can be selected according to product requirements.

[0036] The connection between the grinding wheel holder 41 and the moving disc part 32 can be fixed, meaning that the electric spindle 42 and the grinding wheel 43 cannot swing at any angle, and the axis of the electric spindle 42 remains parallel to the Z-axis. The grinding wheel 43 needs to be shaped and dressed so that its cross-sectional shape matches the tooth groove shape of the external thread 9A.

[0037] Please see Figure 4 The connection between the grinding wheel holder 41 and the moving disc portion 32 can be achieved through a grinding wheel holder oscillation mechanism 33. Specifically, the moving disc portion 32 is equipped with a grinding wheel holder oscillation mechanism 33 that acts on the grinding wheel holder 41. The grinding wheel holder 41 can oscillate around an axis parallel to the X-axis, causing the electric spindle 42 and the grinding wheel 43 to oscillate accordingly. The grinding wheel 43 can freely define its helix angle by oscillating at a corresponding angle to match the external thread 9A.

[0038] In some embodiments, the connection between the grinding wheel holder 41 and the moving disc portion 32 is preferably via a grinding wheel holder swing mechanism 33. Providing the grinding wheel holder swing mechanism 33 on the moving disc portion 32 to act on the grinding wheel holder 41 has a wider range of applications.

[0039] Please see Figure 4Furthermore, the connection positions of grinding wheel frame 41 and grinding wheel frame 51 on the moving disc 32 are opposite. Accordingly, the turret device 3 needs to rotate 180 degrees when switching between the first grinding wheel assembly 4 and the second grinding wheel assembly 5.

[0040] To provide adequate space for the setting of the grinding wheel head swing mechanism 33, referring to some existing grinding wheel head swing mechanisms, the grinding wheel head swing mechanism 33 in this application can adopt a servo motor with a worm gear reducer.

[0041] Please see Figure 3 and Figure 5 In some embodiments, the grinding machine that integrates external thread and tooth profile grinding also has at least one of the following configurations: Configuration 1: It further includes a grinding wheel dresser 6, which is matched with a grinding wheel 43. Configuration 2: It further includes a grinding wheel dresser 7, which is matched with a grinding wheel 53.

[0042] The grinding wheel dresser is set up so that the two-axis module 2 drives the movement and rotation of the corresponding grinding wheel 43 / grinding wheel 53. The grinding wheel 43 / grinding wheel 53 can be dressed directly without disassembling the grinding wheel 43 / grinding wheel 53, avoiding secondary clamping.

[0043] Please see Figure 2 , Figure 3 and Figure 5 Based on embodiments where both grinding wheel dresser 6 and grinding wheel dresser 7 are simultaneously provided, in some embodiments, grinding wheel dresser 6 is provided on the workpiece headstock 1A, and grinding wheel dresser 7 is provided on the bed 1 on the side of the tailstock 1B away from the workpiece headstock 1A.

[0044] When grinding planetary roller 9: The planetary roller 9 is installed between the workpiece headstock 1A and the tailstock 1B of the bed 1, so that the axis of the planetary roller 9 is parallel to the Z-axis of the two-axis module 2.

[0045] The turret device 3 activates the first grinding wheel assembly 4, and the electric spindle 42 drives the grinding wheel 43 to rotate. The two-axis module 2 drives the grinding wheel 43 to move along the Z and X axes. Combined with the rotation of the planetary rollers 9, the grinding wheel 43 grinds the threads of the planetary rollers 9. During this grinding process, the direction of the grinding wheel 43 can be from the machine headstock to the tailstock 1B, and the number of grinding cycles can be specifically set. After grinding is completed, the grinding wheel 43 returns to the machine headstock position, and the grinding wheel dresser 6 dresses the grinding wheel 43.

[0046] The turret device 3 switches the second grinding wheel assembly 5 to work. The electric spindle 2 52 drives the grinding wheel 2 53 to rotate. The two-axis module 2 drives the grinding wheel 2 53 to move on the Z-axis and X-axis. The grinding wheel 2 53 grinds the gear 9B on the side of the machine tool headstock corresponding to the planetary roller 9. The grinding wheel 2 53 replaces the ground teeth in the gear 9B by combining the rotation of the planetary roller 9 with the rotation of the planetary roller 9.

[0047] After all the teeth on one side of the headstock of the planetary roller 9 machine tool are ground, grinding wheel 2 53 grinds the gear 9B on one side of the tailstock 1B of the planetary roller 9. After grinding is completed, grinding wheel 2 53 is dressed by grinding wheel dresser 2 7.

[0048] It is relatively convenient to interweave the dressing of grinding wheel 43 and the dressing of grinding wheel 53 during the grinding process of planetary roller 9.

Claims

1. A grinding machine that integrates external thread and tooth profile grinding, characterized in that, include: The bed (1) is equipped with a workpiece headstock (1A) and a tailstock (1B) that are opposite each other on the Z-axis; The two-axis module (2) is connected to the bed (1) and has linear motion in the Z-axis and X-axis. The turret device (3) has a stationary plate part (31) fixedly connected to the mounting platform of the two-axis module (2); The first grinding wheel assembly (4) includes: a grinding wheel frame (41) connected to the moving disc part (32) of the turret device (3), an electric spindle (42) connected to the grinding wheel frame (41), and a grinding wheel (43) mounted on the electric spindle (42); the grinding wheel (43) is used to grind external threads (9A); The second grinding wheel assembly (5) includes: a second grinding wheel frame (51) connected to the moving disc part (32) of the turret device (3), a second electric spindle (52) connected to the second grinding wheel frame (51), and a second grinding wheel (53) mounted on the second electric spindle (52); the second grinding wheel (53) is used for grinding tooth profile.

2. The grinding machine for integrating external thread and tooth profile grinding according to claim 1, characterized in that, The turntable (1A1) of the workpiece headstock (1A) has a first center (1A2) and a clamp (8); the tailstock (1B) has a second center (1B1); the clamp (8) is used to hold the end of the workpiece and connect the workpiece and the turntable (1A1).

3. A grinding machine for integrating external thread and tooth profile grinding according to claim 2, characterized in that, The clamp (8) includes: a connecting block (81) that can be slidably fixed to the turntable (1A1), a clamping block one (82) connected to the connecting block (81), a clamping block two (83), and a fastener (84) disposed between the clamping block one (82) and the clamping block two (83).

4. A grinding machine for integrating external thread and tooth profile grinding according to claim 1, characterized in that, The moving plate part (32) is provided with a grinding wheel frame swing mechanism (33) that acts on the grinding wheel frame (41).

5. A grinding machine for integrating external thread and tooth profile grinding according to claim 4, characterized in that, The connection positions of grinding wheel holder one (41) and grinding wheel holder two (51) on the moving plate part (32) are opposite.

6. A grinding machine for integrating external thread and tooth profile grinding according to claim 1, characterized in that, It also has at least one of the following settings: Setting 1: It also includes a grinding wheel dresser 1 (6), which is matched with a grinding wheel 1 (43); Setting 2: It also includes a grinding wheel dresser 2 (7), which is matched with a grinding wheel 2 (53).

7. A grinding machine for integrating external thread and tooth profile grinding according to claim 6, characterized in that, Grinding wheel dresser one (6) is set on the workpiece headstock (1A); grinding wheel dresser two (7) is set on the bed (1) on the side of the tailstock (1B) away from the workpiece headstock (1A).

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