CN212286312U

CN212286312U - Laser engraving machine

Info

Publication number: CN212286312U
Application number: CN202020875243.0U
Authority: CN
Inventors: 叶生山
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-01-05
Anticipated expiration: 2030-05-22
Also published as: WO2021232441A1

Abstract

The application provides a laser engraving machine, laser engraving machine includes: a main body; the X-axis movement assembly comprises a sliding support, a first motor, a first transmission assembly and a first shaft, wherein the first motor is mounted on the sliding support, and the sliding support is in sliding fit with the first shaft so that the first shaft can move along a first direction relative to the sliding support; the Y-axis movement assembly comprises a second motor, a second transmission assembly and a second shaft, the second motor and the second shaft are fixedly arranged on the main body, and the second motor can drive the X-axis movement assembly to move along a second direction through the second transmission assembly; the laser emission assembly is fixedly connected to the first shaft, and the first motor can drive the first shaft to drive the laser emission assembly to move. The laser emission assembly is fixedly connected to the first shaft, so that the laser emission assembly does not need to be provided with a transmission assembly, and further, the weight is light and the size is small. The laser engraving machine is easy to keep stable when the laser emitting assembly moves.

Description

Laser engraving machine

Technical Field

The application belongs to the laser processing field, especially relates to a laser engraving machine.

Background

With the development of industrial technology, the advantages of tools using laser as a processing means are gradually highlighted. The laser technology and the application thereof are developed rapidly, and a plurality of application technical fields such as laser processing technology, laser detection and metering technology, laser chemistry, laser medical treatment, laser guidance and the like are developed by combining with a plurality of subjects, and the technologies influence each other and develop together, thereby promoting the more intensive research and application of laser. Among them, the laser processing technology is a technology of performing processing such as cutting, welding, surface treatment, punching, etc. on a material by using a laser beam to act on the material. The low-power semiconductor laser has the advantages of low price, small volume and the like, and can be used for cutting, carving patterns and the like on materials which are easy to process, such as plastics, wood and the like.

The existing semiconductor laser engraving machine uses a 450nm blue light semiconductor laser diode as a processing light source, and a focusing point is formed on a material to be processed after passing through a lens. The microcontroller controls the motor to drive the laser light source to move and control the brightness of the laser light source, and expected light spots can be formed on a material to be processed, so that patterns can be cut and engraved.

As shown in fig. 1, CN107175411A discloses a laser engraving machine, which comprises a laser 10a, an x-axis driving motor 20a, a y-axis driving motor 30a, an x-axis guide rail 40a and a y-axis guide rail 50 a. The x-axis guide rail 40a and the y-axis guide rail 50a are perpendicular to each other, the laser 10a is slidably disposed on the x-axis guide rail 40a, the x-axis drive motor 20a drives the laser 10a to slide along the x-axis guide rail 40a, and the y-axis drive motor 30a drives the x-axis guide rail 40a to slide along the y-axis guide rail 50 a. Sliding the x-axis rail 40a on the y-axis rail 50a allows the laser 10a to move to any point in the plane by sliding the laser 10a on the x-axis rail 40 a. The semiconductor laser diode in the laser 10a has an efficiency of only about 30%, and generates a high temperature during operation.

As shown in fig. 2, CN210498825U discloses a laser engraving machine, which comprises a laser 10b, an x-axis driving motor 20b, a y-axis driving motor 30b, an x-axis guide rail 40b and a y-axis guide rail 50 b. The y-axis guide rail 50b is formed into a frame shape, two y-axis driving motors 30b are arranged, and the two y-axis driving motors 30b drive the x-axis guide rail 40b to move together. The laser 10b is slidably disposed on the x-axis guide rail 40b, and the x-axis drive motor 20b drives the laser 10b to slide along the x-axis guide rail 40 b. The structure is stable and not easy to shake, can bear a high-power laser, and can enlarge the carving area, but the frame structure causes the volume of the whole machine to be larger, and the placement of processing materials is troublesome.

SUMMERY OF THE UTILITY MODEL

The application aims to provide a laser engraving machine, which can have smaller volume while keeping stable operation.

The application provides a laser engraving machine, laser engraving machine includes:

a main body;

an X-axis motion assembly comprising a sliding bracket, a first motor, a first transmission assembly, and a first shaft, the first motor being mounted to the sliding bracket, the first shaft extending in a first direction, the sliding bracket and the first shaft being in sliding engagement such that the first shaft is movable relative to the sliding bracket in the first direction;

the Y-axis movement assembly comprises a second motor, a second transmission assembly and a second shaft, the second motor and the second shaft are fixedly mounted on the main body, the second shaft extends along a second direction, the second direction is perpendicular to the first direction, the sliding support is in sliding fit with the second shaft, and the second motor can drive the X-axis movement assembly to move along the second direction through the second transmission assembly;

the laser emission assembly is fixedly connected to the first shaft, and the first motor can drive the first shaft to drive the laser emission assembly to move along the first direction through the first transmission assembly.

Preferably, the laser emission assembly comprises a laser diode, a radiator and a radiator support, the laser diode is connected with the radiator, the radiator support is tightly attached to the first shaft, and the radiator support is tightly attached to the radiator.

Preferably, the laser emitting assembly further comprises a heat dissipation fan, the heat dissipation fan is disposed on a surface of the heat sink, and air can flow through the heat sink by rotation of the heat dissipation fan.

Preferably, the laser emission subassembly still includes the laser emission subassembly shell, laser diode the radiator support with radiator fan set up in the inside of laser emission subassembly shell, the laser emission subassembly shell is provided with fresh air inlet and exhaust vent, the fresh air inlet with the exhaust vent sets up relatively.

Preferably, the laser emission assembly further comprises a filter cartridge made of a transparent or translucent material capable of filtering at least part of the strong blue light, the filter cartridge being cylindrical, the filter cartridge being capable of enclosing the light emitted by the laser diode.

Preferably, the laser emission assembly further comprises a filter cartridge holder, the filter cartridge is sleeved on the filter cartridge holder, and the filter cartridge holder are slidably connected.

Preferably, the first transmission assembly comprises a first synchronous wheel and a first synchronous belt, the first synchronous wheel is connected to an output shaft of the first motor, the first synchronous belt is connected to the first shaft, and the first synchronous belt is meshed with the first synchronous wheel, so that the first shaft can be driven by the first synchronous belt to drive the laser emission assembly to move.

Preferably, the first transmission assembly further comprises a first driven wheel, and the first driven wheel is in pressing contact with the smooth surface of the first synchronous belt to keep the first synchronous belt in a tensioned state.

Preferably, the second transmission assembly includes a second synchronizing wheel, a second driven wheel and a second synchronizing belt, the second synchronizing wheel is connected to the output shaft of the second motor, the second driven wheel can be rotatably connected to the main body, and the second synchronizing wheel and the second driven wheel are sleeved with the second synchronizing belt.

Preferably, the first axis and the second axis are optical axes,

the X-axis motion assembly further comprises a first linear bearing which is fixedly connected with the sliding support and is in sliding fit with the first shaft;

the Y-axis motion assembly further comprises a second linear bearing which is fixedly connected with the sliding support and is in sliding fit with the second shaft.

By adopting the technical scheme, at least one of the following beneficial effects can be obtained:

(1) the laser emission assembly is fixedly connected to the first shaft, so that the laser emission assembly does not need to be provided with a transmission assembly, and further, the weight of the laser emission assembly can be lighter and the size can be smaller. When the laser emitting assembly moves, the gravity center of the laser engraving machine is easily kept in the range of the main body, and the stability of the laser engraving machine is kept.

(2) The radiator is in close contact with the first shaft, and the heat is dissipated to the outside through the first shaft, so that the heat dissipation efficiency is improved.

(3) At least partial strong blue light emitted by the laser diode is filtered through the shading cylinder, so that the effect of protecting eyes can be achieved.

(4) The transmission part is arranged in the main body, so that the part rotating at high speed cannot be touched when the laser engraving machine operates, the safety is high, and the appearance is attractive.

(5) The service life and the motion precision of the equipment can be improved through the matching and guiding of the linear bearing and the optical axis.

Drawings

Fig. 1 shows a schematic structural diagram of a prior art laser engraving machine.

Fig. 2 shows a schematic view of another prior art laser engraving machine.

Fig. 3 shows a schematic structural diagram of a laser engraving machine according to an embodiment of the present application.

Fig. 4 shows a schematic view of another angle of the laser engraving machine according to an embodiment of the present application.

Fig. 5 shows an internal structural view of a laser engraving machine according to an embodiment of the present application.

Fig. 6 shows a schematic view of another angular internal structure of a laser engraving machine according to an embodiment of the present application.

Fig. 7 shows a partial enlarged view of a laser engraving machine according to an embodiment of the present application.

Fig. 8 shows an exploded view of a laser emitting assembly of a laser engraving machine according to an embodiment of the present application.

Description of the reference numerals

1 main body

The 2X-axis moving assembly 21 slide bracket 22 first motor 23 first synchronous pulley 24 first driven pulley 25 first synchronous belt 26 first linear bearing 27 first shaft 271 first synchronous belt fixing member

Second motor 32, second synchronous wheel 33, second driven wheel 34, second synchronous belt 35, second linear bearing 36 and second shaft of 3Y-axis motion assembly 31

4 laser emission assembly 41 laser diode 42 filter cylinder 43 filter cylinder support 44 heat sink 441 heat sink 45 heat sink support 46 heat sink 47 focusing lens 48 laser driving circuit board 49 laser emission assembly housing 491 laser emission assembly upper housing 4911 air inlet hole 492 laser emission assembly lower housing 4921 air outlet hole

5 line arrangement

X a first direction and Y a second direction.

Detailed Description

In order to more clearly illustrate the above objects, features and advantages of the present application, a detailed description of the present application is provided in this section in conjunction with the accompanying drawings. This application is capable of embodiments in addition to those described herein, and is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this application pertains and which fall within the limits of the appended claims. The protection scope of the present application shall be subject to the claims.

As shown in fig. 3 to 8, the present application provides a laser engraving machine, which includes a main body 1, an X-axis moving assembly 2, a Y-axis moving assembly 3, and a laser emitting assembly 4. The X-axis moving assembly 2 is connected with the Y-axis moving assembly 3, the laser emitting assembly 4 is fixedly connected with the X-axis moving assembly 2, and the laser emitting assembly 4 can move along the first direction X along with the X-axis moving assembly 2. The Y-axis motion assembly 3 is connected to the main body 1, and the X-axis motion assembly 2 can be driven by the Y-axis motion assembly 3 to move along a second direction Y, wherein the first direction X and the second direction Y are perpendicular to each other. The body 1 may be a housing formed by injection molding, making the overall weight of the laser engraving machine light.

(X-axis motion assembly)

As shown in fig. 3 to 7, the X-axis moving assembly 2 includes a sliding bracket 21, a first motor 22, a first synchronizing wheel 23, a first driven wheel 24, a first synchronizing belt 25, a first linear bearing 26, and a first shaft 27.

First motor 22 fixed connection is in sliding support 21, and first synchronous wheel 23 installs in the output shaft of first motor 22, and the output shaft of first motor 22 extends along vertical direction, and vertical direction is all perpendicular with first direction X and second direction Y. First linear bearing 26 fixed connection is in sliding bracket 21, and first axle 27 is located to first linear bearing 26 cover, and first axle 27 extends along first direction X, and first axle 27 can be the optical axis, can improve equipment's life and motion accuracy through first linear bearing 26 and optical axis cooperation direction.

Both ends of the first shaft 27 are provided with first timing belt fixing members 271, and the first timing belt fixing members 271 clamp both ends of the first timing belt 25 so that the first timing belt 25 can be maintained in a tensioned state. The laser transmitter unit 4 may be located at an end of the first shaft 27, and the first timing belt fixing member 271 may be formed at a laser transmitter unit case 49 described later. The outer circumferential surface of the first synchronizing wheel 23 is provided with a tooth groove, one side surface of the first synchronizing belt 25 is provided with a tooth groove, the other side surface is a smooth surface, and the tooth groove of the first synchronizing wheel 23 and the tooth groove of the first synchronizing belt 25 are meshed with each other.

Preferably, the first timing belt fixing member 271 may be provided with a tooth groove, and the first timing belt fixing member 271 can hold the first timing belt 25 by engaging the tooth groove of the first timing belt fixing member 271 with the tooth groove of the first timing belt 25, so that the first timing belt fixing member 271 is not easily dislocated or detached.

The first driven wheel 24 is rotatably connected to the sliding bracket 21, and the first driven wheel 24 and the first synchronizing wheel 23 are at the same height, so that the first synchronizing belt 25 horizontally disposed can be engaged with the first driven wheel 24 and the first synchronizing wheel 23. The first driven wheels 24 may be provided in two, and the two first driven wheels 24 and the first synchronizing wheel 23 are arranged at both sides of the first synchronizing wheel 23 in a triangular arrangement. The smooth surface of the first driven wheel 24 and the first timing belt 25 are in pressing contact, and the first timing belt 25 can be assisted in tensioning by the first driven wheel 24. And the first synchronous belt 25 and the first synchronous wheel 23 are contacted more, and more teeth can be meshed with each other, so that the first synchronous belt 25 and the first synchronous wheel 23 are prevented from slipping. When the first motor 22 is operated, the first shaft 27 can be slid in the first direction X by the transmission of the first synchronizing wheel 23 and the first synchronizing belt 25.

(Y-axis motion component)

As shown in fig. 3 to 7, the Y-axis moving assembly 3 includes a second motor 31, a second timing pulley 32, a second driven pulley 33, a second timing belt 34, a second linear bearing 35, and a second shaft 36.

The second motor 31 is fixedly connected to the main body 1, the second synchronizing wheel 32 is mounted on an output shaft of the second motor 31, and the output shaft of the second motor 31 extends in the horizontal direction. The second driven wheel 33 is rotatably connected to the main body 1, and a rotation shaft of the second driven wheel 33 and an output shaft of the second motor 31 are parallel to each other and on the same horizontal plane. The second timing pulley 32 and the second driven pulley 33 have tooth grooves on their outer peripheral surfaces, and the second timing pulley 34 has a tooth groove on one side surface and a smooth surface on the other side surface. The second timing belt 34 is formed in a closed loop shape, and the second timing belt 34 is fitted over the second timing wheel 32 and the second driven wheel 33 and maintains a tensioned state. The tooth grooves of the second synchronous wheel 32 and the second driven wheel 33 are meshed with the tooth grooves of the second synchronous belt 34, and the second driven wheel 33 and the second synchronous wheel 32 can synchronously rotate through transmission of the second synchronous belt 34.

The second shaft 36 is fixedly connected to the main body 1, the second shaft 36 extends along the second direction Y, the second linear bearing 35 is connected to the sliding bracket 21, the second shaft 36 is sleeved on the second linear bearing 35, and the sliding bracket 21 is fixedly connected to the second synchronous belt 34. The second shaft 36 can be an optical axis, and the service life and the motion precision of the device can be improved through the matching and guiding of the second linear bearing 35 and the optical axis. When the second motor 31 rotates, the sliding bracket 21 can slide in the second direction Y, so that the X-axis moving assembly 2 and the laser emission assembly 4 move together in the second direction Y.

(laser emitting assembly)

As shown in fig. 3 to 5 and 8, the laser emission module 4 includes a laser diode 41, a filter cartridge 42, a filter cartridge holder 43, a heat sink 44, a heat sink holder 45, a heat dissipation fan 46, a focusing lens 47, a laser driving circuit board 48, and a laser emission module case 49.

The laser emitting assembly housing 49 includes a laser emitting assembly upper housing 491 and a laser emitting assembly lower housing 492, the laser emitting assembly upper housing 491 and the laser emitting assembly lower housing 492 being snap-fitted together. The laser diode 41, the heat sink 44, the heat sink bracket 45, the heat sink fan 46, the focusing lens 47, and the laser driving circuit board 48 are all disposed inside the laser emitting assembly housing 49. The upper housing 491 of the laser emitting assembly is provided with an air inlet 4911, the lower housing 492 of the laser emitting assembly is provided with an air outlet 4921, and the air inlet 4911 and the air outlet 4921 can be oppositely arranged to form convection of air and facilitate heat dissipation of the laser diode 41.

A laser driver circuit board 48 is mounted inside the laser emitting assembly housing 49, and the laser driver circuit board 48 can be used for driving the heat dissipation fan 46 to rotate and controlling the light emitting intensity of the laser diode 41. The main body 1 is further provided with a control mainboard and a motor drive board inside, the laser drive circuit board 48 can be connected with the control mainboard through a flexible flat cable 5, and the motor drive board can be connected with the first motor 22 and/or the second motor 31 through the flexible flat cable 5.

The laser diode 41 is fixedly connected to the heat sink 44, and preferably, the heat sink 44 may further have a plurality of fin-shaped heat dissipation fins 441, the heat dissipation fins 441 may be made of a material with good thermal conductivity, such as copper, and the heat dissipation fins 441 can help to quickly dissipate heat to the atmosphere.

The radiator support 45 is sleeved on the end portion of the first shaft 27, and the radiator support 45 is closely attached to and in contact with the first shaft 27. The heat sink 44, the heat sink bracket 45, and the heat sink fan 46 are fixed by being pressed by, for example, a laser emitting module case 49, by the heat sink fan 46 being mounted between the laser emitting module upper case 491 and the laser driving circuit board 48. The heat sink bracket 45 and the heat sink 44 are both disposed between the heat sink fan 46 and the laser emitting module case 49, and the heat sink 44 is in close contact with the heat sink bracket 45 by being pressed by the heat sink fan 46 and the laser emitting module case 49, so that heat is easily conducted among the heat sink bracket 45, the heat sink 44, and the first shaft 27.

It will be appreciated that heat generated by the laser diode 41 may be transferred through the heat sink bracket 45, the heat sink 44, and the first shaft 27 and dissipated into the air. In a possible embodiment, the first shaft 27 may be made of a copper or aluminum material, such as a copper alloy or an aluminum alloy, which may allow for a high heat transfer efficiency. Through the heat dissipation of the first shaft 27 and the heat sink 44, the heat sink 44 can be made smaller in size and lighter in weight, the laser emitting assembly 4 can be made lighter in weight, and the stability of the laser engraving machine can be better.

It will be appreciated that the laser transmitter assembly 4 does not have to have transmission components relative to the body 1 within which components such as the first motor 22, the second motor 31, etc. are disposed, and therefore is lightweight, compact, and also facilitates removal of the laser transmitter assembly 4 for cleaning and maintenance. In particular, the heat sink 44 is made lighter by the first shaft 27 dissipating heat together with the heat sink 44. Therefore, the laser engraving machine has good stability, and the center of gravity can fall in the range of the main body 1.

By the rotation of the heat dissipation fan 46, air can enter the laser emitting assembly housing 49 through the air inlet 4911, flow through the heat sink 44 and the laser diode 41, and flow out of the air outlet 4921, thereby achieving the effect of rapid heat dissipation.

The focusing lens 47 is disposed at a front side of the laser diode 41 so that the light emitted from the laser diode 41 can be focused on the material to be processed via the focusing lens 47. The filter holder 43 may be attached to the focus lens 47, and the filter 42 may have a cylindrical shape. For example, the filter cylinder 42 is cylindrical, the laser diode 41 may be located at one end of the filter cylinder 42, and the light emitted from the laser diode 41 can be emitted from the other end of the filter cylinder 42 in the axial direction of the filter cylinder 42. The filter cylinder 42 is fitted to the filter cylinder holder 43, and the filter cylinder 42 can surround the light emitted from the laser diode 41. The filter cartridge 42 is slidable on the filter cartridge holder 43 in the axial direction of the filter cartridge 42, thereby adjusting the height position of the filter cartridge 42 so that the filter cartridge 42 can be brought close to the material to be processed.

The filter cartridge 42 may be made of a transparent or translucent material capable of filtering at least part of the intense blue light, for example a green transparent or translucent material. The filter cartridge 42 can filter at least a portion of the strong blue light emitted from the laser diode 41, such as light having a wavelength of 400nm to 440nm, and has an eye protection effect. Therefore, the engraving effect can be watched in real time when the laser engraving machine is used, and special blue-light-proof glasses do not need to be worn.

It is to be understood that, although in the above-described embodiments, the X-axis moving assembly 2 and the Y-axis moving assembly 3 each include a timing belt and a timing wheel to realize transmission, they are merely examples of constituent components of the first transmission assembly and the second transmission assembly of the present application, and the present application is not limited thereto, and may be replaced by other transmission means, for example, the first timing belt and the first timing wheel may be replaced by a rack and pinion, a chain and a sprocket, or the like.

Claims

1. A laser engraving machine, characterized in that it comprises:

a main body (1);

an X-axis motion assembly (2), the X-axis motion assembly (2) comprising a sliding bracket (21), a first motor (22), a first transmission assembly and a first shaft (27), the first motor (22) being mounted to the sliding bracket (21), the first shaft (27) extending in a first direction (X), the sliding bracket (21) and the first shaft (27) being in sliding engagement such that the first shaft (27) is movable relative to the sliding bracket (21) in the first direction (X);

the Y-axis movement assembly (3) comprises a second motor (31), a second transmission assembly and a second shaft (36), the second motor (31) and the second shaft (36) are fixedly mounted on the main body (1), the second shaft (36) extends along a second direction (Y), the second direction (Y) is perpendicular to the first direction (X), the sliding support (21) is in sliding fit with the second shaft (36), and the second motor (31) can drive the X-axis movement assembly (2) to move along the second direction (Y) through the second transmission assembly;

laser emission subassembly (4), laser emission subassembly (4) fixed connection in first axle (27), first motor (22) can pass through first transmission assembly drive first axle (27) drive laser emission subassembly (4) are followed first direction (X) moves.

2. The laser engraving machine according to claim 1, wherein said laser emitting assembly (4) comprises a laser diode (41), a heat sink (44) and a heat sink support (45), said laser diode (41) being connected to said heat sink (44), said heat sink support (45) being in close abutment with said first shaft (27), said heat sink support (45) being in close abutment with said heat sink (44).

3. The laser engraving machine according to claim 2, wherein the laser emitting assembly (4) further comprises a heat dissipating fan (46), the heat dissipating fan (46) being disposed on a surface of the heat sink (44), and air can be made to flow through the heat sink (44) by rotation of the heat dissipating fan (46).

4. The laser engraving machine according to claim 3, wherein the laser emitting assembly (4) further comprises a laser emitting assembly housing (49), the laser diode (41), the heat sink (44), the heat sink bracket (45) and the heat dissipating fan (46) are disposed inside the laser emitting assembly housing (49), the laser emitting assembly housing (49) is provided with an air inlet hole (4911) and an air outlet hole (4921), and the air inlet hole (4911) and the air outlet hole (4921) are oppositely disposed.

5. The laser engraving machine according to claim 2, wherein the laser emitting assembly (4) further comprises a filter cartridge (42), the filter cartridge (42) being made of a transparent or translucent material capable of filtering at least part of the intense blue light, the filter cartridge (42) being cylindrical, the filter cartridge (42) being capable of enclosing the light emitted by the laser diode (41).

6. The laser engraving machine according to claim 5, wherein said laser emitting assembly (4) further comprises a filter cartridge holder (43), said filter cartridge (42) being sleeved on said filter cartridge holder (43), said filter cartridge (42) and said filter cartridge holder (43) being slidably connected.

7. The laser engraving machine according to claim 1, wherein the first transmission assembly comprises a first synchronizing wheel (23) and a first synchronizing belt (25), the first synchronizing wheel (23) is connected to an output shaft of the first motor (22), the first synchronizing belt (25) is connected to the first shaft (27), and the first synchronizing belt (25) and the first synchronizing wheel (23) are engaged, so that the first shaft (27) can be driven to move the laser emitting assembly (4) through the first synchronizing belt (25).

8. The laser engraving machine according to claim 7, wherein said first transmission assembly further comprises a first driven wheel (24), said first driven wheel (24) being in pressing contact with the smooth surface of said first synchronous belt (25) to keep said first synchronous belt (25) in tension.

9. The laser engraving machine according to claim 1, wherein the second transmission assembly comprises a second synchronizing wheel (32), a second driven wheel (33) and a second synchronous belt (34), the second synchronizing wheel (32) is connected to an output shaft of the second motor (31), the second driven wheel (33) is rotatably connected to the main body (1), and the second synchronizing wheel (32) and the second driven wheel (33) are sleeved with the second synchronous belt (34).

10. Laser engraving machine according to claim 1, characterized in that said first shaft (27) and said second shaft (36) are optical axes,

the X-axis motion assembly (2) further comprises a first linear bearing (26) fixedly connected with the sliding support (21) and in sliding fit with the first shaft (27);

the Y-axis motion assembly (3) further comprises a second linear bearing (35) fixedly connected with the sliding support (21) and in sliding fit with the second shaft (36).