Drive device with a hypocycloid gear assembly for a forming machine

Abstract

A drive device (10) for a forming machine (11) includes a hypocycloid gear assembly (20) having an eccentric gear (23), a stationary annulus gear (24) and a planetary gear system (28). The planetary gear system (28) includes an orbiting gear (29) orbiting and rolling in an annulus gear (24). The orbiting gear (29) is connected to at least one first planetary gear (35). On the first planetary gear (35), a first planetary gear equalization mass (m.sub.2) is disposed diametrically opposite an output bearing. At least one first eccentric gear equalization mass (m.sub.3) is arranged on the eccentric gear (23). The first eccentric gear equalization mass (m.sub.3) is arranged diametrically opposite, relative to a planetary gear axis (PA) about which the planetary gear system (28) rotates. The resultant forces and torques acting on the annulus gear (24) can at least be reduced by the equalization masses.

Claims

1. Drive device (10) for a forming machine (11), the drive device comprising: a hypocycloid gear assembly (20a) comprising a planetary gear system (28) having an annulus gear (24) arranged coaxially with respect to an annulus gear axis (HA), an orbiting gear (29) orbiting in the annulus gear (24) and being rotatable about a planetary gear axis (PA) and being in a driven connection with an eccentric rotating element (23), and a first planetary rotating element (35) rigidly connected to the orbiting gear (29) and having a mass m.sub.p1, an output bearing (30) arranged on the planetary gear system (28), a ram (15) and push rod (12) connected to the output bearing (30) to provide a first mass (m.sub.1) driven by the planetary gear system (28), a first planetary gear equalization mass (m.sub.2) being arranged on the planetary system (28) and being diametrically opposite the output bearing (30), relative to the planetary gear axis (PA), a first eccentric gear equalization mass (m.sub.3) being arranged on the eccentric rotating element (23) and being diametrically opposite the planetary gear axis (PA), relative to the annulus gear axis (HA), a second eccentric gear equalization mass (m.sub.4) arranged on the eccentric rotating element (23), said second eccentric equalization mass being located diametrically opposite the first eccentric gear equalization mass (m.sub.3), relative to the annulus gear axis (HA), an internal toothing (24a) for the planetary gear system (28) provided on the annulus gear (24) that meshes with external toothing (29a) of an orbiting gear (29) of the planetary gear system (28), wherein the annulus gear (24) defines, at a right angle to the annulus gear axis (HA), an annulus gear plane (HE) that corresponds to a longitudinal center plane through the internal rolling surface (241) on the annulus gear (24), wherein the first planetary gear equalization mass (m.sub.2) and the first eccentric gear equalization mass (m.sub.3), and/or the second eccentric gear equalization mass (m.sub.4) are located outside the annulus gear plane (HE), wherein the first planetary gear equalization mass (m.sub.2) is at a first distance (x.sub.1) with respect to the annulus gear plane (HE), and that the first eccentric gear equalization mass (m.sub.3) is at a second distance (x.sub.3) with respect to the annulus gear plane (HE), and that the second eccentric gear equalization mass (m.sub.4) is at a third distance (x.sub.4) with respect to the annulus gear plane (HE), wherein during operation of the drive device, the first mass (m.sub.1) generates a first force F.sub.1, the first planetary gear equalization mass (m.sub.2) generates a second force F.sub.2, the first eccentric gear equalization mass (m.sub.3) generates a third force F.sub.3, the second eccentric gear equalization mass (m.sub.4) generates a fourth force F.sub.4, and the first planetary rotating element (35) generates a planetary gear force F.sub.P1, which are related according to 0=F.sub.12+F.sub.p1F.sub.3+F.sub.4 and 0=x.sub.1.Math.F.sub.12+X.sub.p1.Math.F.sub.p1x.sub.3.Math.F.sub.3+x.sub.4.Math.F.sub.4, where m.sub.12=m.sub.1=m.sub.2 and F.sub.12 is force resulting from the first force F.sub.1 and the second force F.sub.2.

2. Drive device as in claim 1, wherein a dimension of the first distance (x.sub.1) is different from a dimension of the second distance (x.sub.3) and/or the third distance (x.sub.4).

3. Drive device as in claim 1, wherein the dimension of the second distance (x.sub.3) is different from a dimension of the third distance (x.sub.4).

4. Drive device as in claim 1, wherein the first eccentric gear equalization mass (m.sub.3) and the second eccentric gear equalization mass (m.sub.4) are arranged on opposite sides relative to the annulus gear plane (HE).

5. Drive device as in claim 1, wherein the first planetary gear equalization mass (m.sub.2) and the first eccentric gear equalization mass (m.sub.3) are arranged on the same side, relative to the annulus gear plane (HE).

6. Drive device as in claim 1, wherein the planetary gear system (28) comprises the first planetary rotating element (35) and a second planetary rotating element (36) that are arranged on opposite sides relative to the eccentric rotating element (23), wherein the first planetary gear equalization mass (m.sub.2) is arranged on the planetary rotating element (35) and is located diametrically opposite the output bearing (30), relative to the planetary gear axis (PA), and that a second planetary gear equalization (m.sub.5) is arranged on the second planetary rotating element (36).

7. Drive device as in claim 6, wherein a bearing equalization mass (m.sub.6) is arranged on the second planetary rotating element (36).

8. Drive device as in claim 7, wherein the second planetary gear equalization mass (m.sub.5) is located diametrically opposite the bearing equalization mass (m.sub.6), relative to the planetary axis (PA).

9. Drive device as in claim 8, wherein a position of the bearing equalization mass (m.sub.6) in peripheral direction about the planetary gear axis (PA) corresponds to the output bearing's (30) position in peripheral direction about the planetary gear axis (PA), and/or that the first planetary gear equalization mass's (m.sub.2) position in peripheral direction about the planetary axis (PA) corresponds to the second planetary gear equalization mass's (m.sub.5) position in peripheral direction about the planetary gear axis (PA).

10. Forming machine (11) for the production of hollow cylindrical bodies from a starting part (14), the forming machine comprising: a drive device (10) comprising: a hypocycloid gear assembly (20a) comprising a planetary gear system (28) having an annulus gear (24) arranged coaxially with respect to an annulus gear axis (HA), an orbiting gear (29) orbiting in the annulus gear (24) and being rotatable about a planetary gear axis (PA) and being in a driven connection with an eccentric rotating element (23), and a first planetary rotating element (35) rigidly connected to the orbiting gear (29) and having a mass m.sub.p1, an output bearing (30) arranged on the planetary gear system (28), a ram (15) and push rod (12) connected to the output bearing (30) to provide a first mass (m.sub.1) driven by the planetary gear system (28), a first planetary gear equalization mass (m.sub.2) being arranged on the planetary gear system (28) and being diametrically opposite the output bearing (30), relative to the planetary gear axis (PA), and a first eccentric gear equalization mass (m.sub.3) being arranged on the eccentric rotating element (23) and being diametrically opposite the planetary gear axis (PA), relative to the annulus gear axis (HA), a second eccentric gear equalization mass (m.sub.4) arranged on the eccentric rotating element (23), said second eccentric equalization mass being located diametrically opposite the first eccentric gear equalization mass (m.sub.3), relative to the annulus gear axis (HA), an internal toothing (24a) for the planetary gear system (28) provided on the annulus gear (24) that meshes with external toothing (29a) of an orbiting gear (29) of the planetary gear system (28), wherein the annulus gear (24) defines, at a right angle to the annulus gear axis (HA), an annulus gear plane (HE) that corresponds to a longitudinal center plane through the internal rolling surface (241) on the annulus gear (24), wherein the first planetary gear equalization mass (m.sub.2) and the first eccentric gear equalization mass (m.sub.3), and/or the second eccentric gear equalization mass (m.sub.4) are located outside the annulus gear plane (HE), wherein the first planetary gear equalization mass (m.sub.2) is at a first distance (x.sub.1) with respect to the annulus gear plane (HE), and that the first eccentric gear equalization mass (m.sub.3) is at a second distance (x.sub.3) with respect to the annulus gear plane (HE), and that the second eccentric gear equalization mass (m.sub.4) is at a third distance (x.sub.4) with respect to the annulus gear plane (HE), wherein during operation of the drive device, the first mass (m.sub.1) generates a first force F.sub.1, the first planetary gear equalization mass (m.sub.2) generates a second force F.sub.2, the first eccentric gear equalization mass (m.sub.3) generates a third force F.sub.3, the second eccentric gear equalization mass (m.sub.4) generates a fourth force F.sub.4, and the first planetary rotating element (35) generates a planetary gear force F.sub.p1, which are related according to 0=F.sub.12+F.sub.p1F.sub.3+F.sub.4 and 0=x.sub.1.Math.F.sub.12+X.sub.p1.Math.F.sub.p1x.sub.3.Math.F.sub.3+x.sub.4.Math.F.sub.4, where m.sub.12=m.sub.1=m.sub.2 and F.sub.12 is force resulting from the first force F.sub.1 and the second force F.sub.2.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 a principle of a drive device comprising a hypocycloid gear assembly in order to illustrate the basic function of the drive device;

(2) FIG. 2 a schematic representation of different pitch circle diameters of the hypocycloid gear assembly as in FIG. 1 and the movement of the output bearing;

(3) FIG. 3 a schematic representation resembling a block circuit diagram of an exemplary embodiment of a first exemplary embodiment of the drive device;

(4) FIG. 4 the forces or torques resulting from the exemplary embodiment as in FIG. 3 and acting on the annulus gear;

(5) FIG. 5 a schematic representation resembling a block circuit diagram of a second exemplary embodiment of the drive device; and

(6) FIG. 6 the schematic illustration of the resultant forces and torques acting on the annulus gear in the exemplary embodiment of FIG. 5.

(7) The invention relates to a drive device 10 for a forming machine 11 that is represented by a block circuit diagram in FIG. 1. The forming machine 11 comprises a push rod 12 that performs a stroke movement H along an axis A (FIG. 2). Together with a forming tool 13 interacting with the push rod 12, it is possible to make hollow cylindrical bodies from a starting part 14. The starting part may be a metal sheet, a circular blank or a so-called cup.

(8) In order to perform the stroke movement, the push rod 12 is mounted to a rod 15. The ram 15 extends along the axis A. This rod may be supported at one or several locations so as to be movable back and forth along the axis A via a bearing arrangement.

(9) Associated with the drive device 10 is a hypocycloid gear assembly 20 that is driven at a drive input 21 by a driving motor 22, for example an electric motor. The drive input 21 is provided on an eccentric gear 23. The hypocycloid gear assembly 20 is further associated with an annulus gear 24 that is provided with internal toothing 24a, said toothing representing an internal rolling surface of the annulus gear 24. The internal toothing 24a is arranged coaxially about an annulus gear axis HA. The annulus gear 24 is arranged so as to be immovable relative to a machine frame 25 of the forming machine 11.

(10) A planetary gear system 28 of the hypocycloid gear assembly 20 comprises an orbiting gear 29. The orbiting gear 29 has an external rolling surface formed by external toothing 29a. The external toothing 29a meshes with the internal toothing 24a of the annulus gear 24 at the engagement site. The planetary gear system 28 is connected to the eccentric gear 23 in a driving manner. In one drive of the driving motor 22, the eccentric gear 23 moves the orbiting gear 29 in such a manner that said orbiting gear rolls inside the annulus gear 24. In doing so, the planetary gear system 28 is supported so as to be appropriately rotatable relative to the eccentric gear 23.

(11) An output bearing 30 is arranged on the planetary gear system 28, in which case the planetary gear system 28 thus represents a gearing output 31. The ram 15 is supported by the output bearing 30.

(12) In the hypocycloid gear assembly 20, the output bearing 30 is arranged on the pitch circle TU of the orbiting gear 29. During operation of the drive device 10, the pitch circle TU of the orbiting gear 29 rolls in the pitch circle TH of the annulus gear 24, as is schematically illustrated by FIG. 2. The pitch circle diameter of the pitch circle TU of the orbiting gear 29 is half the size of the pitch circle diameter of the pitch circle TH of the annulus gear 24. As a result of this, the output bearing 30 moves linearly along the axis A when the orbiting gear 29 orbits in the annulus gear 24.

(13) FIG. 3 shows a first exemplary embodiment 20a of a hypocycloid gear assembly 20 for a first embodiment of the drive device 10, schematized in a block circuit diagram. An annulus gear plane HE extends at a right angle relative to the annulus gear axis HA. The annulus gear plane HE extends centrally through the internal rolling surface formed by internal toothing 24a. The orbiting gear 29 of the planetary gear system 28 is preferably centered relative to the annulus gear plane HE. The eccentric gear 23 extends through the annulus gear plane HE. In order to support the orbiting gear 29 or the planetary gear system 28, the eccentric gear 23 may have a recess at a peripheral point so that the eccentric gear is not rotation-symmetrical relative to its axis of rotation that, in accordance with the example, coincides with the annulus gear axis HA. A first planetary gear 35 is rigidly connected to the orbiting gear 29. The first planetary gear 35 and the orbiting gear 29 may also be configured in one piece as one cylindrical component.

(14) The output bearing 30 is arranged on the first planetary gear 35, where the ram 15 and the push rod 12 are located. This results in a first mass m.sub.1 that is to be driven. The maximum first radial distance r.sub.1 of the first mass m.sub.1 of the annulus gear axis HA is shown in FIG. 3. A first planetary gear equalization mass m.sub.2 is arranged on the first planetary gear 35 relative to the planetary gear axis PA diametrically opposite the first mass m.sub.1, i.e., diametrically opposite the output bearing 30. The planetary gear axis PA or the point of gravity of the planetary gear system 28 is at a second radial distance r.sub.2 from the annulus gear axis HA.

(15) Arranged on the eccentric gear 23 is a first eccentric gear equalization mass m.sub.3. This first eccentric gear equalization mass m.sub.3 is arrangedrelative to the annulus gear plane HEon the same side as the first planetary gear equalization mass m.sub.2. On the opposite side of the annulus gear plane HErelative to the annulus gear axis HA and diametrically opposite the first eccentric gear equalization mass m.sub.3there is arranged a second eccentric gear equalization mass m.sub.4 on the eccentric gear 23. The second eccentric gear equalization mass m.sub.3 is located opposite the annulus gear axis HA, diametrically opposite the planetary gear axis PA.

(16) Due to the various masses, a force is generated on the respective annulus gear 24: The first mass m.sub.1 generates a first force F.sub.1, the first planetary gear equalization mass m.sub.2 generates a second force F.sub.2, the first eccentric gear equalization mass m.sub.3 generates a third force F.sub.3, the second eccentric gear equalization mass m.sub.4 generates a fourth force F.sub.4, and the first planetary gear 35 generates a planetary gear force F.sub.P1. In doing so, the following relationships apply:
F.sub.1=m.sub.1.Math.r.sub.1.Math..sup.2.Math.cos(t)(1)
F.sub.2=m.sub.2.Math.r.sub.1.Math..sup.2.Math.sin(t)(2)

(17) wherein (1) and (2) with m.sub.12=m.sub.1=m.sub.2 result in:
F.sub.12=m.sub.12.Math.r.sub.1.Math..sup.2(3)
F.sub.3=m.sub.3.Math.r.sub.1.Math..sup.2(4)
F.sub.P1=m.sub.P1.Math.r.sub.2.Math..sup.2(5)

(18) wherein m.sub.P1 is the mass of the first planetary gear 35.

(19) In order for the forces acting on the annulus gear 24 to equalize, the following must be satisfied:

(20) $\begin{matrix} 0 \overset{!}{=} F_{12} + F_{P 1} - F_{3} + F_{4} & (6) \end{matrix}$

(21) Equation (6) then results in:

(22) $\begin{matrix} m_{3} = m_{12} + m_{4} + \frac{r_{2}}{r_{1}} .Math. m_{P 1} & (7) \end{matrix}$

(23) FIG. 4 shows a graph of the distances and the masses, respectively, from the annulus gear plane HE. The first planetary gear equalization mass m.sub.2 is at a first distance x.sub.1 from the annulus gear plane HE. The first eccentric gear equalization mass m.sub.3 is at a second distance x.sub.3, and the second eccentric gear equalization mass M.sub.4 is at a third distance x.sub.4 from the annulus gear plane HE. The point of gravity of the first planetary gear 35 is at a fourth distance x.sub.P1 from the annulus gear plane HE. In order for the torques resulting from the forces on the annulus gear 24 to be equalized, the following relationship must be satisfied:

(24) $\begin{matrix} 0 \overset{!}{=} x_{1} .Math. F_{12} + x_{P 1} .Math. F_{P 1} - x_{3} .Math. F_{3} - x_{4} .Math. F_{4} & (8) \end{matrix}$

(25) Using equation (8) as well as the equalization of the forces on the annulus gear 24, it is possible to determine the equalization masses, so that, during the operation of the drive device 10 and the first hypocycloid gear assembly 20a, respectively, the resultant force, as well as the resultant torque, on the annulus gear 24 can be eliminated in the ideal case or at least reduced.

(26) FIG. 5 shows an additional, second embodiment of a hypocycloid gear assembly 20b for a second drive device 10. Different from the first hypocycloid gear assembly 20a, the second hypocycloid gear assembly 20b uses a modified planetary gear system 28. In addition to the first planetary gear 35, the planetary gear system 28 has a second planetary gear 36. The second planetary gear 36 may have essentially the same configuration as the first planetary gear 35. The two planetary gears 35, 36 are arranged on opposite sides relative to the annulus gear plane HE. A second planetary gear equalization mass m.sub.5 and, in accordance with the example, also a bearing equalization mass m.sub.6, are arranged on the second planetary gear 36. The second planetary gear equalization mass m.sub.5 and the bearing equalization mass m.sub.6 are arranged, relative to the planetary gear axis PA, diametrically opposite on the second planetary gear 36. In peripheral direction about the planetary gear axis PA, the second planetary gear equalization mass m.sub.5 has the same position as the first planetary gear equalization mass m.sub.2 of the first planetary gear 35. Accordingly, the bearing equalization mass m.sub.6 has preferably the same position as the first mass m.sub.1, i.e., that output bearing 30, in peripheral direction about the planetary gear axis PA.

(27) In the exemplary embodiment of the second hypocycloid gear assembly 20b described here, it is possible to omit the second eccentric gear equalization mass m.sub.4. Likewise, in the first hypocycloid gear assembly 20a, it is possiblein a modified embodimentto optionally omit the second eccentric gear equalization mass m.sub.4.

(28) Analogous to the description of the first exemplary embodiment, a fifth force F.sub.5 results from the second planetary gear equalization mass M.sub.5 and a sixth force F.sub.6 from the bearing equalization mass m.sub.6, as follows:
F.sub.5=m.sub.5.Math.r.sub.1.Math..sup.2.Math.sin(t)(9)
F.sub.6=m.sub.6.Math.r.sub.1.Math..sup.2.Math.cos(t)(10)

(29) Due to the mass m.sub.P2 of the second planetary gear 36, there results a second planetary gear force F.sub.P2, namely:
F.sub.P2=m.sub.P2.Math.r.sub.2.Math..sup.2(11)

(30) The fifth force F.sub.5 and the sixth force F.sub.6 can be used analogously to equations (1) to (3) where m.sub.56=m.sub.5=m.sub.6 to determine the following equation:
F.sub.56=m.sub.56.Math.r.sub.1.Math..sup.2(12)

(31) The distances in axial direction (x-direction) from the annulus gear plane HE of the masses or the points of contact of the forces of the exemplary embodiment of FIG. 5 are schematically illustrated in FIG. 6. The force F.sub.56 resulting from the fifth force F.sub.5 and the sixth force F.sub.6 is at a fifth distance x.sub.5 from the annulus gear plane HE, and the point of gravity of the second planetary gear 36 is at a sixth distance x.sub.P2 from the annulus gear plane HE. The remaining forces are analogous to the first hypocycloid gear assembly 20a, as is shown in FIGS. 3 and 4 and described hereinabove.

(32) Corresponding to the first hypocycloid gear assembly 20a, it is also possible to provide an at least partial force equalization and torque equalization for the second hypocycloid gear assembly 20b. Based thereon, it is possible to then determine the individual masses in order to optimize the second hypocycloid gear assembly 20b such that the lowest possible resultant forces and torques act on the annulus gear 24.

(33) The invention relates to a drive device 10 for a forming machine 11. The drive device 10 comprises a hypocycloid gear assembly 20. The hypocycloid gear assembly 20 comprises an eccentric gear 23, a stationary annulus gear 24 and a planetary gear system 28. The planetary gear system 28 includes an orbiting gear 29 orbiting and rolling in an annulus gear 24. The orbiting gear 29 is connected to at least one first planetary gear 35 of the planetary gear system 28. Alternatively, a planetary gear 35, 36 each may be arranged on opposite sides of the orbiting gear 29. On the first planetary gear 35, there is provided a first planetary gear equalization mass m.sub.2 diametrically opposite an output bearing. At least one first eccentric gear equalization mass m.sub.3 and, optionally, a second eccentric gear equalization mass m.sub.4, are arranged on the eccentric gear 23. The first eccentric gear equalization mass m.sub.3 is arranged diametrically opposite, relative to a planetary gear axis PA about which the planetary gear system 28 rotates. The resultant forces and torques acting on the annulus gear 24 can at least be reduced by the equalization masses.

LIST OF REFERENCE SIGNS

(34) 10 Drive device 11 Forming machine 12 Push rod 13 Forming tool 14 Starting part 15 Ram 16 Bearing arrangement 20 Hypocycloid gear assembly 20a First hypocycloid gear assembly 20b Second hypocycloid gear assembly 21 Drive input 22 Driving motor 23 Eccentric gear 24 Annulus gear 24a Internal toothing 25 Machine frame 28 Planetary gear system 29 Orbiting gear 29a External toothing 30 Output bearing 31 Gearing output 35 First planetary gear 36 Second planetary gear A Axis H Stroke movement HA Annulus gear axis HE Annulus gear plane PA Planetary gear axis F.sub.1 First force F.sub.2 Second force F.sub.3 Third force F.sub.4 Fourth force F.sub.P1 First orbiting gear force m.sub.1 First mass m.sub.2 First planetary gear equalization mass m.sub.3 First eccentric gear equalization mass m.sub.4 Second eccentric gear equalization mass m.sub.5 Second planetary gear equalization mass m.sub.6 Bearing equalization mass m.sub.P1 Mass of the first planetary gear m.sub.P2 Mass of the second planetary gear r.sub.1 First radial distance r.sub.2 Second radial distance TH Pitch circle of the annulus gear TU Pitch circle of the orbiting gear x.sub.1 First distance x.sub.3 Second distance x.sub.4 Third distance x.sub.P1 Fourth distance x.sub.5 Fifth distance x.sub.P2 Sixth distance

Drive device with a hypocycloid gear assembly for a forming machine

Assignee

Inventors

Cpc classification

Classification Explorer

B30B1/266

PERFORMING OPERATIONS; TRANSPORTING

Classification Explorer

F16H21/365

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Classification Explorer

Y10T74/18056

GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

Classification Explorer

B21D51/26

PERFORMING OPERATIONS; TRANSPORTING

Classification Explorer

B30B15/0064

PERFORMING OPERATIONS; TRANSPORTING

International classification

Classification Explorer

B21D51/26

PERFORMING OPERATIONS; TRANSPORTING

Classification Explorer

B30B15/00

PERFORMING OPERATIONS; TRANSPORTING

Classification Explorer

B30B1/26

PERFORMING OPERATIONS; TRANSPORTING

Classification Explorer

F16H21/36

MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING

Abstract

Claims

Description