RU2325571C2 - Device for backlash-free torque transmission and method for installation thereof - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: said device for backlash-free torque transmission comprises drive gear (1) engaged with two toothed rims (3, 4) of driven gear. One of the rims (4) can be swivelled as regards to the other rim (3). Rim (4) interacts with shaft (5) end via elastically twisted torsion bar (8). The device installation is based on dowelling torsion bar (8) as regards to mobile toothed rim (4) in elastically twisted condition.

EFFECT: enhanced produceability of the device, load-carrying capacity thereof and accuracy of backlash-free torque transmission.

2 cl, 4 dwg

Description

The proposed technical solution relates to the field of mechanical engineering and can be used in reversing mechanisms, where a high-precision transmission of the angle of rotation from the leading link to the follower is required.

Known devices for backlash-free transmission of torque, made on the basis of split wheels, containing a driven gear in the form of two gear rims. One of the crowns is rigidly mounted on the shaft, and the second is spring-loaded and mounted coaxially with the first, see, for example, “Handbook of the designer of optical-mechanical devices”, ed. M.Ya. Kruger, Mash., L., 1968, S. p. 562, 563, p.p. 18-21 and A.S. No. 602727, USSR, IPC F16H 55/18, publ. 04/15/1978, Bull. No. 14.

A device for transmitting torque, containing a leading gear wheel, is engaged with a driven gear made in the form of two coaxially arranged gear rims, the first of which is rigidly fixed to the end of the shaft, and the second is installed with the possibility of rotation relative to the first, see a .from. No. 601498, USSR, IPC F16H 55/18, publ. 04/05/1978, Bull. No. 13.

The method of mounting the device includes mounting the first gear ring of the driven gear on the shaft end, installing a second gear ring on the shaft end of the driven gear with its fixation from axial displacement, and engaging the driving gear with the first and second gear rings.

The disadvantage of all of the above devices is their reduced load capacity, due to the specifics of the implementation of the elastic elements, providing backlash selection in the design.

The closest technical solution (prototype) to the proposed one is a device for backlash-free transmission of torque, containing a driving gear gear engaged with a driven gear made of two axially aligned gear rims, the first of which is rigidly fixed to the end of the shaft having an axial end cavity, and the second is made with an axial protrusion and an inner radial collar, and mounted on the shaft with the possibility of rotation relative to the first, as well as a torsion bar mounted in the cavity shaft and fixed at one end in the bottom of the cavity of the shaft, the second - located in the axial protrusion of the second gear ring, see.with. No. 1221425, USSR, IPC F16H 55/24, 1981

The mounting method of the device includes mounting the first gear ring of the driven gear on the shaft end, placing the torsion shaft end in the axial end cavity of the torsion bar fixing its first end from the crank in the bottom of the cavity, installing a second gear ring on the shaft end of the gear with fixing it from axial displacement and the engagement of the drive gear with the first and second gears.

The disadvantages of the technical solutions are:

1. Low manufacturability associated with the complexity of the design of the torsion bar spin mechanism (the presence of additional elements - a supporting washer, a cracker, a ball and an additional protrusion on the gear wheel).

2. The small load capacity of the structure due to the small areas of the contacting surfaces during the transmission of torques (the moment is transmitted by a spherical body).

3. The inconvenience during operation associated with the mandatory presence of two-way access to the structure during its installation.

4. Reduced accuracy of the transmitted torque without backlash, due to the lack of a strictly regulated torque force of the torsion bar (the value of the moment will introduce errors from the tolerance on the constituent elements of the spin mechanism, mechanical properties of the material, etc.).

The technical result from the use of the proposed technical solution is to increase the load capacity of the device, its manufacturability and the accuracy of the transmitted torque without backlash.

In accordance with the proposed technical solution, the specified technical result is achieved by the fact that in the device for backlash-free transmission of torque, containing a driving gear gear meshed with a driven gear made of two axially arranged gear rims, the first of which is rigidly fixed to the shaft end having an axial end cavity, and the second is made with an axial protrusion and an inner radial collar and mounted on the shaft with the possibility of a turn relative to the first, as well as a torus Zion installed in the shaft cavity and fixed at one end in the bottom of the shaft cavity, the second placed in the axial protrusion of the second gear ring, the second end of the torsion bar is made with a protruding shank for twisting, covered by an inner radial shoulder of the second gear ring and mounted with the possibility of axial rotation the protrusion of the second gear ring for subsequent fixation of the position after the elastic twisting of the torsion bar.

In the method of mounting the device, including mounting the first gear ring of the driven gear on the shaft end, placing in the axial end cavity of the shaft end of the torsion bar with fixing its first end from turning in the bottom of the cavity, installing a second gear ring of the driven gear on the shaft end with fixing it from axial displacement and the engagement of the drive gear with the first and second gears, after the engagement of the drive gear with the first and second gears is locked in l-rotation, the torsion bar is twisted elastically by applying to its shank torque exceeding maximum operating torque on the shaft, and a second end fixed elastically twisted torsion relative to the second toothing of the driven gear.

In addition, the fixation of the second end of the elastically twisted torsion bar relative to the second gear ring of the driven gear wheel is carried out by pinning.

Figure 1 presents the proposed technical solution by the example of a drive for moving the telescope along the corner-place; figure 2-4 - operations according to the method of mounting the device for backlash-free transmission of torque.

The proposed device comprises a drive gear 1 connected to the drive 2, engaged with a driven gear made of two axially arranged gear rims 3 and 4 (gear rims 3 and 4 are made in the form of sectors, see figure 4). The ring gear 3 is rigidly fixed to the end of the shaft 5 (half shaft connected to the telescope 6), and the ring 4 is made with an axial protrusion 7 to cover the shaft 5 and mounted on the latter with the possibility of a turn. The device also contains a torsion bar 8, mounted in the axial end cavity 9 provided on the end of the shaft 5, and fixed by the first end in the bottom of the specified cavity. To eliminate the axial displacement of the crown 4, a screw 10 is provided, screwed into the crown 3, and for convenience of mounting the device on the end surface of the axial protrusion 7, an internal radial protrusion 11 is made to cover the second end of the torsion 8. The torsion 8 is elastically twisted and fixed with its second end relative to the axial protrusion 7 of the crown 4 using the pin 12. To twist the torsion bar 8 at its second end, a shank 13 is provided that protrudes beyond the end surface of the axial protrusion 7 of the crown 4.

When the telescope 6 is rotated through an angle of elevation during reverse, there is a backlash-free transmission of rotation from the drive 2 to the shaft 5 due to the elastic forces in the twisted torsion 8 (the torque of the torsion 8 is selected from the condition that the maximum working moment on the shaft 5 of the telescope 6 is exceeded).

The installation of the device for backlash-free transmission of torque is as follows.

The gear ring 3 is rigidly fixed to the end of the shaft 5 (while introducing the ring 3 into engagement with the drive gear 1, see FIG. 2), the torsion bar 8 is placed in the axial end cavity 9 and its first end is fixed in the bottom of the cavity, fixing from turn, set on the end of the shaft 5 with its axial protrusion 7, the ring gear 4, introducing it also into engagement with the drive wheel 1 and fix the ring gear 4 from the axial displacement using the screw 10 (see figure 2). Then, the shaft 5 is locked from turning, for example, by means of an abutment 14 (see Fig. 4) acting on the telescope 6, and a force P is applied to the shank 13 using a lever 14 of length L, elastically twisting the torsion with a torque (PL) exceeding the maximum working moment on the shaft 5. And after the elastic twisting of the torsion bar 8, fix its second end relative to the axial protrusion 7 of the ring gear 4 using the pin 12 (see figure 1).

From the above it follows that the proposed technical solution when used gives a technical result, which consists in increasing the load capacity of the device due to the transmission of torque by a pin connection (rather than a spherical body), increasing manufacturability by simplifying the torsion bar twist unit (the twist unit is made only in the form of a shank the second end of the torsion bar), increasing the accuracy of the transmitted torque without backlash due to the presence of a regulated torque of the torsion bar, ensuring mounting Ms design from one side.

Based on the application materials, the enterprise has currently made a prototype device, tests of which have confirmed the achievement of the specified technical result.

Claims (2)

1. Device for backlash-free transmission of torque, comprising a drive gear engaged with a driven gear made of two axially aligned gear rims, the first of which is rigidly fixed to the end of the shaft having an axial end cavity, and the second is made with an axial protrusion and an internal radial collar and mounted on the shaft with the possibility of a turn relative to the first, as well as a torsion bar mounted in the cavity of the shaft and fixed at one end in the bottom of the shaft cavity, the second - located in axial protrusion of the second gear ring, characterized in that the second end of the torsion bar is made with a protruding shank for twisting it, is surrounded by an inner radial flange of the second gear ring and mounted with the possibility of rotation in the axial protrusion of the second gear ring for subsequent fixation of the position after the elastic twisting of the torsion bar. 2. A method of mounting a device for backlash-free transmission of torque, including mounting the first gear ring of the driven gear at the end of the shaft, placing the torsion shaft end in the axial end cavity, fixing its first end from turning in the bottom of the cavity, installing a second gear ring on the shaft end the driven gear with its fixation from axial displacement, the engagement of the driving gear with the first and second gears, and the subsequent elastic twisting of the torsion bar until which increases the maximum working moment on the shaft, characterized in that after the drive gear is engaged with the first and second gear rims, the shaft is prevented from turning, and the torsion is twisted elasticly by applying torque to the shank of its second end, followed by fixing the second end of the elastically twisted torsion bar relative to the second gear ring of the driven gear by pinning.

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