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DE-102025111671-B3 - Cycloidal gearbox with two transmission stages, drive unit, method for operating the drive unit and gripping or clamping device with such a gearbox

DE102025111671B3DE 102025111671 B3DE102025111671 B3DE 102025111671B3DE-102025111671-B3

Abstract

The invention relates to a gearbox (16), in particular for use in electronic gripping or clamping directions, a drive unit (10) and electronic gripping or clamping devices (120), wherein the gearbox comprises a drive shaft (24), an eccentric (28), a first internal gear (30), a first external gear (38), a second internal gear (32), a second external gear (40), a first output element (46), a second output element (48) and an output shaft (58).

Inventors

  • Sven Briemle

Assignees

  • HEINZ-DIETER SCHUNK GMBH & CO. SPANNTECHNIK KG

Dates

Publication Date
20260513
Application Date
20250326

Claims (16)

  1. The transmission (16) comprises: a drive shaft (24), an eccentric (28), a first inner gear (30) comprising teeth (34), a first outer gear (38) comprising teeth (42), a first output element (46), and an output shaft (58), wherein the drive shaft (24) and the output shaft (58) are arranged coaxially to each other along a longitudinal axis (12) of the transmission, wherein the drive shaft (24) and the eccentric (28) are connected to each other in a rotationally fixed manner, wherein the first inner gear (30) is at least one largely centrally arranged, preferably circular, main recess (31), wherein the eccentric (28) is arranged in the main recess (31) of the first inner gear (30), wherein the eccentric (28) and the first inner gear (30) are rotatable relative to each other, wherein the first inner gear (30) and the first outer gear (38) have a different number of teeth (34, 42), wherein the first inner gear (30) rolls on the first outer gear (38) and thereby executes an elliptical movement around the longitudinal axis (12) of the transmission, wherein the first inner gear (30) has several secondary recesses (33), wherein the secondary recesses (33) are arranged around the main recess (31), wherein the first output element (46) has several drive pins (47), wherein the The drive pins (47) have a smaller diameter than the secondary recesses (33) of the first inner gear (30), the drive pins (47) being arranged to engage correspondingly in the secondary recesses (33) of the first inner gear (30), characterized in that the transmission (16) comprises a second inner gear (32) comprising teeth (36), the first inner gear (30) and the second inner gear (32) being rotationally fixed to one another, the transmission (16) comprising a second outer gear (40) comprising teeth (44), the second inner gear (32) rolling in and driving the second outer gear (40), the transmission (16) comprising a second output element (48), the second output element (48) being rotationally fixed to the second outer gear (40). is, wherein the transmission (16) comprises a switching device (53), wherein the switching device (53) can be selectively engaged with the first output element (46) or with the second output element (48), and wherein the switching device (53) engages with the output shaft (58).
  2. Gearbox (16) after Claim 1 , characterized in that the second inner gear (32) and the second outer gear (40) have a different number of teeth (36, 44), wherein the difference in the number of teeth (34, 42) of the first inner gear (30) and the first outer gear (38) and the difference in the number of teeth (36, 44) of the second inner gear (32) and the second outer gear (40) are equal.
  3. Gearbox (16) after Claim 1 or 2 , characterized in that the first internal gear (30) and the second internal gear (32) have a different number of teeth (34, 36).
  4. Gearbox (16) according to one of the preceding claims, characterized in that the first inner gear (30) and the second inner gear (32) are connected to each other in a displaceable manner.
  5. Gearbox (16) according to one of the preceding claims, characterized in that the second outer gear (40) and the second output element (48) are connected to each other in a displaceable manner.
  6. Transmission (16) according to one of the preceding claims, characterized in that the switching device (53) comprises a clutch element (54) which can be displaced along the longitudinal axis (12) of the transmission.
  7. Gearbox (16) after Claim 6 , characterized in that the coupling element (54) is connected to at least one positive locking element (56) in a rotationally fixed manner, wherein optionally the first output element (46) or the second output element (48) engages positively in the positive locking element (56).
  8. Gearbox (16) after Claim 7 , characterized in that the first output element (46) engages radially in recesses (60) of the positive locking element (56) or the second output element (48) engages axially in recesses (62) of the positive locking element (56).
  9. Gearbox (16) according to one of the Claims 6 until 8 , characterized in that the switching device (53) comprises at least one displacement device (68) which can displace the clutch element (54) along the longitudinal axis (12) of the transmission.
  10. Gearbox (16) according to one of the preceding claims, characterized in that the first outer gear (38) is connected to a housing (20) of the gearbox (16) in a rotationally fixed and, in particular, also displaceably fixed manner.
  11. Gearbox (16) according to one of the preceding claims, characterized in that the drive shaft (24) and the eccentric (28) are positively connected to each other.
  12. Drive unit (10), in particular for use in electronic gripping or clamping devices, comprising a gearbox (16) according to one of the Claims 1 until 11 , a control device (18) and an electric motor (14), wherein an output shaft (22) of the electric motor (14) is non-rotatably connected to the drive shaft (24) and/or is formed integrally with the drive shaft (24).
  13. Drive unit (10) after Claim 12 , characterized in that the control device (18) is configured to engage the switching device (53) either with the first output element (46) or with the second output element (48) depending on at least one controlled variable.
  14. Drive unit (10) after Claim 13 , characterized in that the at least one controlled variable comprises a sensor signal and/or a length dimension and/or a diameter dimension and/or a distance dimension and/or a weight dimension and/or a position dimension and/or a load dimension and/or an external input value.
  15. Method for operating the drive unit (10) according to Claim 14 , characterized in that, in the case of large distance dimensions, the switching device (53) is brought into engagement with the first output element (46), and/or in the case of large weight dimensions or large load dimensions, the switching device (53) is brought into engagement with the second output element (48).
  16. Electronic gripping or clamping device (120) comprising the drive unit (10) according to one of the Claims 12 until 14 and at least two gripping or clamping elements (124) for gripping and/or clamping a component.

Description

The invention relates to a gearbox, in particular for use in electronic gripping or clamping devices, a drive unit, a method for operating the drive unit and an electronic gripping or clamping device. Electronic gripping or clamping devices have several movable gripping or clamping elements that can clamp the component to be fixed. An electric motor is used to drive the gripping or clamping elements, and its power output corresponds to the product of its rotational speed and torque. To generate the forces necessary for gripping or clamping the components, the torque provided by the electric motor is increased in a gearbox. As a result, due to the inversely proportional relationship, the rotational speed and thus the travel speed of the gripping or clamping elements decreases. Consequently, gripping or clamping components that require a long travel distance of the gripping or clamping elements is very time-consuming. In particular, changing between components with a large diameter and those with a small diameter is inefficient. From the EP 3 301 323 and the EP 3 301 324 Cycloidal gears with two gear stages are known. JP H05 39 235 Y2 reveals a reduction gearbox. From the US 4 807 494 A A planetary gear with a stepwise adjustable gear ratio is known. CN 102 787 469 A reveals a fully automatic delay clutch for washing machines. The invention is based on the objective of providing a gearbox, a drive unit and an electronic gripping or clamping device that enables efficient gripping or clamping of components, in particular with different diameters. This problem is solved by a transmission according to claim 1. Further developments of the transmission are the subject of claims 2 to 11. The problem is further solved by a drive unit according to claims 12 to 14. The problem is further solved by a method for operating a drive unit according to the invention according to claim 15. The problem is further solved by an electronic gripping or clamping device according to claim 16. The transmission comprises a drive shaft, an eccentric, a first inner gear, and a first outer gear. The first inner gear and the first outer gear each have several teeth, which are arranged in a uniform distribution along their respective outer and inner circumferences. The teeth of the first inner and outer gears are rounded and have arcuate flanks. The teeth of the first inner gear are designed as cams, and the teeth of the first outer gear are designed as rollers. The transmission also includes a first output element and an output shaft, which provides an interface to subsequent assemblies, such as a clamping unit with gripping or clamping elements. The drive shaft and the output shaft are arranged coaxially with each other along a longitudinal axis of the transmission. The drive shaft and the eccentric are connected to each other in a rotationally fixed and preferably also a displacement-fixed manner. It is possible for the drive shaft and the eccentric to be supplied separately and, in particular, connected to each other in a rotationally fixed manner by means of a positive-locking connection, preferably by means of polygonal surfaces. This enables a modular design of the gearbox and ensures reliable torque transmission. Alternatively, it is possible for the drive shaft and the eccentric to be formed in one piece. This reduces assembly effort. The eccentric has an eccentric center located on an eccentric plane that runs orthogonally to the longitudinal axis of the gearbox. The eccentric center is spaced from the longitudinal axis of the gearbox by an eccentricity measure. The first inner gear has at least one largely centrally arranged, preferably circular, main recess. The eccentric is arranged in the main recess of the first inner gear, wherein the eccentric and the first inner gear are rotatable relative to each other. It is preferred if a rotary bearing, in particular a plain bearing, a ball bearing, or a needle bearing, is arranged between the main recess and the eccentric. In this way, the frictional forces acting between the eccentric and the first inner gear can be reduced. The first inner gear and the first outer gear have a different number of teeth. The first inner gear rolls against the first outer gear, performing an elliptical (cycloidal) motion around the longitudinal axis of the gear. The first inner gear has several, in particular circular, secondary recesses. The secondary recesses are arranged around the main recess, in particular at equal angular intervals to each other on a circular line concentric to the main recess. The first output element has several drive pins that have a smaller diameter than the secondary recesses of the first inner gear. Preferably, the diameter of the drive pins is smaller than the diameter of the secondary recesses of the first inner gear by at least approximately twice the eccentricity of the eccentric. The drive pins are arranged so that they engage correspondingly in the secondary recesses