Patent Application
20230341278
The present invention relates to an arrangement for detecting a torque on a machine element, wherein a sleeve with a magnetized region is arranged on the machine element. Furthermore, the invention relates to a vehicle having such an arrangement for detecting a torque on a machine element.
Torque measuring systems for rotating machine elements are known which work on the basis of inverse magnetostriction. Some of these torque measuring systems can use magnetized components, such as a mechanical shaft, a flange or a sleeve on a shaft, as the primary sensor. These magnetized components usually require a special sensor material.
A torque sensor arrangement with a regionally magnetized sleeve is known from DE 2017 127 547 A1. The arrangement is used to determine a torque on a machine element. The sleeve with a magnetization region is arranged on the machine element, wherein the magnetization region is spaced radially apart from the machine element. The magnetization region of the sleeve extends between a first end region and a second end region of the sleeve. The sleeve is firmly mechanically attached to the machine element by means of the end regions. Furthermore, the arrangement comprises a first and a second spacer ring, wherein both spacer rings are each arranged between an end region of the sleeve and the machine element and are fastened thereto. At least one magnetic field sensor is arranged opposite the sleeve.
DE 10 2017 121 863 A1 describes an arrangement for measuring a force and/or a torque on a machine element. The arrangement comprises a magnetic field sensor and a sleeve opposite the magnetic field sensor which has a magnetization region. The sleeve is attached to the machine element in two axially spaced attachment regions. An intermediate region is formed axially between the two attachment regions, in which intermediate region the sleeve is rotatably arranged.
Based on the prior art, one object of the present invention is to provide an improved torque measuring arrangement which has an improved signal quality in relation to the prior art. Furthermore, it is the object of the present invention to provide a vehicle having such an arrangement.
The stated object is achieved by an arrangement for detecting a torque on a machine element according to appended claim 1 and by a vehicle having an arrangement for detecting a torque on a machine element according to independent claim 9.
The arrangement according to the invention for detecting a torque on a machine element comprises a sleeve arranged on the machine element. The machine element and the sleeve are arranged coaxially to one another. The sleeve has a magnetized or magnetizable region. Furthermore, the arrangement comprises a magnetic field sensor, which is arranged opposite the sleeve and interacts therewith. A torque of the machine element can be detected by means of the sleeve abutting the machine element, acting as the primary sensor, and the magnetic field sensor opposite the sleeve. The sleeve accordingly forms a primary sensor. Measurement is carried out on the basis of inverse magnetostriction. The arrangement further comprises an intermediate sleeve made of a non-magnetic material, which is arranged between the machine element and the sleeve. Thus, the machine element, the sleeve and the intermediate sleeve are coaxial to one another. The intermediate sleeve has one or more elevations on each of its two end regions, wherein the intermediate sleeve abuts the machine element by means of the elevations. The elevations are preferably formed radially on the inside. The sleeve and the intermediate sleeve are connected to one another for conjoint rotation, in particular in a force-fitting manner. For its part, the intermediate sleeve is connected to the machine part for conjoint rotation, in particular in a force-fitting manner.
The advantage of a non-magnetic intermediate sleeve with elevations, which can also be referred to as a stepped intermediate sleeve, is that the magnetized or magnetizable sleeve is magnetically decoupled from the shaft. The non-magnetic intermediate sleeve prevents magnetic field lines from the magnetized region of the sleeve from penetrating into the machine element at its edges or end regions.
Penetration of the field lines into the machine element would reduce the flux density. A reduction in flux density leads to poor signal quality. The signal quality of the measurement signal can thus be improved by the arrangement according to the invention with an intermediate sleeve, since the field lines are prevented or at least reduced from crossing over into the machine element and there is an increased, uniform flux density on the sleeve.
A further advantage of the arrangement according to the invention with an intermediate sleeve is that the torque between the machine element and sleeve can be introduced and/or removed in a targeted manner, since only the elevations of the end regions of the intermediate sleeve abut the machine element.
Advantageously, by fitting the sleeve onto the intermediate sleeve, micro-slippage of the sleeve is prevented. At the same time, there is advantageously an even mechanical stress distribution over the entire length of the sleeve, so that the signal quality is also improved compared to the prior art.
The machine element is preferably a rotating or a stationary or a moving component. The machine element is particularly preferably a shaft, in particular a rotating shaft. For example, the shaft is a transmission shaft in a vehicle. Alternatively, the machine element can be a flange.
Preferably, the magnetic region of the sleeve is made of a magnetic material. The magnetized region of the sleeve can particularly preferably be formed by magnetic tracks. The magnetic tracks are preferably arranged circumferentially on the sleeve. The magnetic tracks preferably run parallel. The magnetic tracks are particularly preferably arranged circumferentially in parallel on the sleeve, wherein the magnetic tracks run in the axial direction.
Particularly preferably, only a central region of the sleeve is magnetized. Alternatively, the entire sleeve is preferably magnetized or made of a magnetic material. A magnetized region formed on the sleeve has the advantage that no strain gage and thus no additional measuring component is required.
The sleeve and the intermediate sleeve are preferably connected by a permanent joining method. For example, the sleeve and the intermediate sleeve are connected to one another for conjoint rotation by means of laser welding, alternatively by means of soldering.
In one embodiment, the intermediate sleeve has a radially outer recess in the region between the two end regions, wherein the region forms a central section along the longitudinal axis. The recess of the intermediate sleeve is preferably formed opposite the magnetized region of the sleeve so that a gap is present between the magnetized region of the sleeve and the intermediate sleeve.
In one embodiment, the intermediate sleeve is milled from a solid material, wherein a radially inner recess is milled out in order to form the radially inner elevations. Furthermore, the preferred radially outer recess can be formed by milling.
In an alternative embodiment, the intermediate sleeve is stamped and bent from sheet metal. In this embodiment, the edge regions of the metal sheet are shaped in such a way that elevations are formed at the end regions of the intermediate sleeve and the ends of the metal sheet preferably extend radially outwards so that a radially outer recess is advantageously formed at the same time.
The recess of the intermediate sleeve preferably extends circumferentially. The elevations of the intermediate sleeve preferably extend circumferentially so that the sleeve is completely decoupled from the machine element.
The intermediate sleeve is preferably arranged on the machine element in a rotationally fixed manner. Advantageously, the intermediate sleeve with the sleeve attached thereto can be slid onto machine elements manufactured by different companies. A variable, simple use of the arrangement for detecting a torque is thus possible.
The vehicle according to the invention having an arrangement for detecting a torque on a machine element has a previously described arrangement for detecting a torque, wherein all the specified embodiments and combinations thereof are applicable.
Possible vehicles in which the arrangement according to the invention can be installed are, for example, agricultural machines, electric vehicles, hybrid vehicles, and the like. The arrangement according to the invention is primarily used in transmissions.
The vehicle preferably has an evaluation unit for evaluating the measurement data recorded by the arrangement.
Further advantages and details of the present invention arise from the following description of preferred embodiments with reference to the attached drawing. In the figures:
The structure of the intermediate sleeve 02 with the sleeve 03 on the shaft 01 and the gap 09 located in between allows the mechanical stress on the sleeve to be evenly distributed, as a result of which the signal quality remains high.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 117 007.6 | Jun 2020 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DE2021/100324 | 4/8/2021 | WO |
