Parking lock wheel and parking lock device, as well as drive system for a vehicle with a parking lock device

Abstract

Parking lock wheel for a vehicle, with a wheel hub (1) and a wheel rim (2) on which at least two pawl gaps (3) are provided, which in an axial direction of the parking lock wheel have a pawl gap width (b) K ) exhibit, characterized in that the wheel rim (2) between the pawl gaps (3) has a wheel rim width (b R ) exhibits a gap width that is smaller than the latch gap width (b K ), wherein the cross-section of the wheel rim (2) extends between each pair of the pawl gaps (3) over the wheel rim width (b) R ) tapered towards a center between the pawl gaps (3), and a radial wheel rim thickness (d R ) between two parietal gaps (3) is constant.

Description

[0001] The invention relates to a parking lock wheel according to the features of the preamble of patent claim 1.

[0002] A sudden stop of a moving vehicle's drivetrain is counteracted by the drivetrain's cumulative mass moment of inertia, which is composed of the mass moments of inertia of the individual moving components of the drivetrain. One of these components is the parking lock gear, which, after a pawl engages, secures the vehicle's parking position through a positive connection between the pawl and the parking lock gear.

[0003] In the constant effort to reduce wear during vehicle braking, efforts are being made to reduce the cumulative mass moment of inertia of the drive train. To achieve this, moving components are increasingly being designed with lightweight construction and thus reduced mass. The dimensions of the parking lock gear are determined in particular by the dimensions of the pawl and must have a rim with pawl gaps whose pawl gap width is at least equal to the pawl width. To reduce the mass of parking lock gears, it is known not to design the entire parking lock gear with a width (measured in the axial direction) equal to the pawl gap width. To achieve this, a connecting area between the wheel hub and the rim is made narrower without compromising the stability of the parking lock gear.Stamped parking lock gears are also known, which have a constant width and feature material recesses between the wheel hub and the wheel rim to reduce mass. While both a narrower design of the connecting area between the wheel hub and the wheel rim and recesses in a constant-width parking lock gear lead to a noticeable reduction in the mass of the parking lock gear, the moment of inertia of the parking lock gear is not noticeably reduced to the same extent.

[0004] From the prior art, constructions with a parking lock gear are known from the disclosures DE 10 2019 118 828 A1, CN 1 08 799 492 A, JP 2002-282 954 A and CN 2 07 049 289 U.

[0005] The object of the invention is to find a parking lock gear with a comparatively low moment of inertia. Furthermore, a braking device with a parking brake with a comparatively low moment of inertia and a drive unit with a braking device with a comparatively low moment of inertia are to be found.

[0006] The problem is solved for a parking lock wheel for a vehicle, having a wheel hub and a wheel rim on which a plurality of pawl gaps are present which have a pawl gap width in an axial direction of the parking lock wheel, in that the wheel rim between the pawl gaps has a wheel rim width which is smaller than the pawl gap width, wherein the cross section of the wheel rim tapers between each two of the pawl gaps over the wheel rim width to a center between the pawl gaps, and a radial wheel rim thickness between two pawl gaps is constant. which, compared to a parking lock gear with a constant wheel rim width equal to the pawl gap width, saves material and thus mass on the circumference of the parking lock gear, which has a maximum effect on reducing the mass moment of inertia.

[0007] To further reduce mass, the wheel hub and the wheel rim are advantageously connected only by spokes. For optimal power flow via the parking lock gear between an engaging pawl and an axle on which the wheel hub sits, a spoke is arranged radially between each of the pawl gaps and the wheel hub.

[0008] The cross-section of the wheel rim between each two of the pawl gaps is optimally tapered continuously across the wheel rim width to a center between the pawl gaps and a radial wheel rim thickness is constant.

[0009] The cross-section of the spokes advantageously has a constant spoke width in the axial direction of the parking lock wheel and a spoke thickness perpendicular to this decreases continuously towards a center of the spoke, so that the spoke tapers towards the center.

[0010] For a braking device for a vehicle with a parking brake, the object is achieved in that the parking brake contains a parking lock wheel according to the invention.

[0011] For a drive system for a vehicle with a braking device, the object is achieved in that the braking device contains a parking brake with a parking lock wheel according to the invention.

[0012] The invention is explained in more detail below with reference to a drawing.

[0013] This shows: Fig. 1 an advantageous embodiment of a parking lock wheel in perspective view.

[0014] The Fig. The parking lock gear shown in Figure 1 can be divided into a wheel hub 1, a wheel rim 2 with a plurality of pawl gaps 3, and a number of spokes 4 corresponding to the plurality of pawl gaps 3. The pawl gaps 3 each represent an interface between the parking lock gear and an engaging pawl and are therefore determined in their shape and size by the shape and size of the pawl. Likewise, the size of the wheel hub 1 is largely predetermined by the diameter of the axle on which the parking lock gear is to be arranged. The diameter of the parking lock gear is also determined by the spatial arrangement of the pawl mechanism relative to the axle and / or other components of a braking device into which the parking lock gear is integrated. The parking lock gear is loaded by the force flow between the pawl and the axle when the pawl engages in one of the pawl gaps 3 or when the pawl is engaged when the vehicle is parked on a slope.

[0015] There is another force flow in electric drives: that from the inertia of the electric motor via the rotor shaft to the parking lock gear. This can exceed the other load case due to the rigid shaft connection.

[0016] Taking into account the power flow, as in Fig. 1, the spokes 4 are optimally arranged radially between the pawl gaps 3 and the wheel hub 1. They have a spoke width bs, which is constant over the length of the spokes 4, limited by the wheel hub 1 and the wheel rim 2, and is equal to or only slightly smaller than a pawl gap width b K The spoke thickness ds varies depending on the distance from the wheel hub 1. Starting at the wheel rim 2, the spoke thickness ds first decreases toward the center of spoke 4 and then steadily increases again. There are no abrupt changes in the spoke thickness ds, so there are no steps in the surface of spokes 4. With a number of spokes equal to the number of pawl gaps 3, their arrangement radially below the pawl gaps 3 and their centrally tapered design, a connection area is created on the parking lock wheel between the wheel hub 1 and the wheel rim 2 with a minimum of material and thus mass, which has a beneficial effect on the mass moment of inertia of the parking lock wheel.

[0017] However, a more effective solution for a small moment of inertia is the reduction in material and thus mass of the parking lock gear compared to prior art parking lock gears, by making the wheel rim 2 narrower on connecting pieces between the pawl gaps 3. In order to compensate for jumps in a wheel rim width b R To avoid this, it changes continuously, starting from the latch gap width b K up to a width minimum in the middle between two pawl gaps 3, and then increases again accordingly. A wheel rim thickness d Ris constant over the entire wheel rim 2, whereby the wheel rim 2 is always over the pawl gap lengths I K is reinforced by the adjacent spokes 4. Preferably, the spoke thickness ds adjacent to the wheel rim 2 is greater than or at least equal to the pawl gap length I K .

[0018] Due to the low mass of the parking lock gear in the connection area between the wheel hub 1 and the wheel rim 2 and in particular the low mass of the wheel rim 2, the mass moment of inertia is considerably reduced compared to parking lock gears known from the prior art.

[0019] That is Fig. The parking lock gear shown in Figure 1 is a particularly advantageous design. Parking lock gears with a different cross-sectional shape of the spokes 4 or the wheel rim 2 between the pawl gaps 3 are conceivable. The shape of the pawl gaps 3 and their number are given here only as examples. Reference symbol 1 wheel hub 2 wheel rim 3 Jack gap 4 spokes b R Rim width d R Rim thickness b K Jack gap width I K Jack gap length bs spoke width ds spoke thickness

Claims

[1] Parking lock wheel for a vehicle, comprising a wheel hub (1) and a wheel rim (2) on which at least two pawl gaps (3) are present, which in an axial direction of the parking lock wheel have a pawl gap width (b K ), characterized by that the wheel rim (2) between the pawl gaps (3) has a wheel rim width (b R ) which is smaller than the latch gap width (b K ), whereby the cross-section of the wheel rim (2) between each two of the pawl gaps (3) extends over the wheel rim width (b R ) tapered towards a center between the pawl gaps (3), and a radial wheel rim thickness (d R ) between two pawl gaps (3) is constant. [2] Parking lock wheel according to claim 1, characterized by that the wheel hub (1) and the wheel rim (2) are connected to each other via spokes (4). [3] Parking lock wheel according to claim 2, characterized bythat one of the spokes (4) is arranged radially between one of the pawl gaps (3) and the wheel hub (1). [4] Parking lock wheel according to claim 1, 2 or 3, characterized by that the cross section of the wheel rim (2) between each two of the pawl gaps (3) extends over the wheel rim width (b R ) tapers continuously towards the middle between the pawl gaps (3). [5] Parking lock wheel according to one of claims 3 or 4, characterized by that a cross-section of the spokes (4) has a constant spoke width (bs) in the axial direction of the parking lock wheel and a spoke thickness (ds) perpendicular thereto tapers continuously towards a center. [6] Parking lock device for a vehicle with a parking lock, characterized by that the parking lock includes a parking lock gear according to one of claims 1 to 5. [7] Drive system for a vehicle with a parking lock device, characterized bythat the parking lock device is designed according to claim 6.

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