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DE-102019103613-B4 - Axle center gear

DE102019103613B4DE 102019103613 B4DE102019103613 B4DE 102019103613B4DE-102019103613-B4

Abstract

Axle center drive (11) for transmitting a drive torque received from a drive device (13), preferably an electric motor, to two half-axles of an axle of a vehicle, wherein the axle center gear (11) comprises a transmission gear (17) for translating a drive torque received at an input element (21) with at least two selectable transmission ratios and a differential gear (19) for distributing the translated drive torque to two output elements (59), wherein the transmission gear (17) has a first gear stage (25) which is designed as a planetary gear and comprises a first sun gear (29), a first planet carrier (31) with one or more planet gears (33) and a first ring gear (35), and wherein the transmission gear (17) has a second gear stage (27) designed as a planetary gear and comprising a second sun gear (37), a second planet carrier (39) with one or more planet gears (41) and a second ring gear (43), wherein the first sun wheel (29) forms the aforementioned input element (21), the first planet carrier (31) is stationary and the second sun wheel (37) can be coupled or coupled to the first ring wheel (35) for common rotation, characterized by that the second planet carrier (39) is connected to the differential gear (19) in order to transmit the drive torque translated by the transmission gear (17). to output to the differential gear (19), wherein the transmission gear (17) comprises a switchable clutch device (47) by means of which the second ring gear (43) can be optionally coupled to the first ring gear (35) in a rotationally fixed manner or fixed in a stationary position.

Inventors

  • Thomas Bauer

Assignees

  • KESSLER & CO. GMBH & CO. KG

Dates

Publication Date
20260513
Application Date
20190213

Claims (12)

  1. Axle center transmission (11) for transmitting a drive torque received from a drive device (13), preferably an electric motor, to two half-shafts of an axle of a vehicle, wherein the axle center transmission (11) comprises a transmission (17) for translating a drive torque received at an input element (21) with at least two selectable transmission ratios and a differential (19) for distributing the translated drive torque to two output elements (59), wherein the transmission (17) has a first transmission stage (25) designed as a planetary gear set and comprises a first sun gear (29), a first planet carrier (31) with one or more planet gears (33) and a first ring gear (35), and wherein the transmission (17) has a second transmission stage (27) designed as a planetary gear set and comprises a second sun gear (37), a second planet carrier (39) with one or more planet gears (41) and a second ring gear (43) comprising, wherein the first sun gear (29) forms the said input element (21), the first planet carrier (31) is stationary and the second sun gear (37) can be coupled or coupled to the first ring gear (35) for common rotation, characterized in that the second planet carrier (39) is connected to the differential gear (19) in order to output the drive torque translated by the transmission gear (17) to the differential gear (19), wherein the transmission gear (17) comprises a switchable clutch device (47) by means of which the second ring gear (43) can be selectively coupled to the first ring gear (35) in a rotationally fixed manner or fixed in a stationary position.
  2. Axle center drive (11) according to the general term of Claim 1 , characterized in that the second ring gear (43) is connected to the differential gear (19) in order to transmit the drive torque translated by the transmission gear (17) to the differential gear (19), wherein the transmission gear (17) comprises a switchable clutch device (47) by means of which the second planet carrier (39) can be optionally coupled to the first ring gear (35) in a rotationally fixed manner or fixed in a stationary position.
  3. Axle center drive (11) after Claim 1 or 2 , wherein the coupling device (47) is designed as a claw coupling and is configured to be synchronized by the drive device (13) in order to be able to be shifted while driving.
  4. Axle center drive (11) according to one of the preceding claims, wherein the coupling device (47) can be switched into a neutral position in which it neither couples the respective element of the second gear stage (27) rotationally fixed to the first ring gear (35) nor fixes it in a stationary position.
  5. Axle center drive (11) according to one of the preceding claims, wherein the second sun gear (37) is mounted on the first planet carrier (31) via at least one support bearing (61).
  6. Axle center drive (11) according to one of the preceding claims, wherein at least one lubricant channel (63) is formed in the first planet carrier (31) to direct lubricant axially into the area between the first gear stage (25) and the second gear stage (27) and preferably radially inwards.
  7. Axle center drive (11) after Claim 5 and 6 , wherein the lubricant channel (63) is designed to direct lubricant to the at least one support bearing (61).
  8. Axle center gear (11) according to one of the preceding claims, wherein the second sun gear (37) and the first ring gear (39) are coupled via a connecting section (45) in which one or more lubricant passages (65) are formed, through which lubricant can pass from the first gear stage (25) to the second gear stage (27).
  9. Axle center drive (11) after Claim 8 , wherein the lubricant passages (65) open into an annular space (67) formed between the second sun gear (37), the connecting section (45) and the second planet carrier (39) and open into the lubricant channels (69) formed in the second planet carrier (39) to direct lubricant from the annular space (67) to the planet gears (41) of the second planet carrier (39).
  10. Axle drive (15) with an axle center drive (11) according to one of the preceding claims and with a drive device (13) which is connected to the input element (21) to form a to transmit the drive torque of the drive device (13) to the axle center gear (11).
  11. drive axle with an axle center gear (11) according to one of the Claims 1 until 9 or with an axle drive (15) to Claim 10 , wherein the drive axle further comprises two half-axles, each of which is connected to one of the two output elements (59) in order to receive a respective part of the drive torque translated by the axle center gear (11) and distributed to the output elements (59).
  12. drive axle after Claim 11 , wherein the half-axles each comprise a drive shaft and a wheel hub and are designed for independent wheel suspension.

Description

The present invention relates to an axle center drive for transmitting a drive torque received from a drive device to two half-axles of an axle of a vehicle. Such a center-mounted axle drive can, in particular, include a differential for distributing the respective drive torque to the two half-shafts. Depending on the application and, in particular, on the type of drive device from which the center-mounted axle drive receives drive torque, it may be advantageous to first reduce the drive torque to a slower or faster speed before it reaches the differential. For example, if the drive device is an electric motor or other high-speed motor, it may be provided that the drive torque is first reduced to lower speeds. An example application for such an axle center-drive unit is a vehicle that has one or more permanently driven axles, particularly those powered by an internal combustion engine, and at least one selectable drive axle driven by an electric motor. The electric motor's drive torque is reduced via the axle center-drive unit and distributed to two half-shafts of the selectable drive axle, particularly to implement selectable all-wheel drive. However, the aforementioned drive axle need not be selectable; it can also be permanently driven, for example, for permanent all-wheel drive. The vehicle could be, for instance, a fire engine or an off-road vehicle. For flexible use across different speed ranges, it is advantageous if the drive torque output by the respective drive device can be selectively multiplied, particularly by reduction. Different gear ratios can be achieved, for example, by switchable wheel hub gears. Especially for axles with independent suspension and/or vehicles with low ground clearance, as well as for drive devices with particularly high rotational speeds, it is advantageous if different gear ratios can be achieved directly in the axle center differential. For this purpose, a reduction gear for multiplying the drive torque with at least two selectable gear ratios can be arranged upstream of the differential, so that the differential then receives a pre-multiplied drive torque and distributes it to two output elements, each of which can be connected to a half-shaft of the driven axle. Such a center-mounted axle drive comprises both a differential and a transmission, but should nevertheless have the most compact design possible. However, this compact design makes cooling and lubrication of the axle drive components more difficult, as there is very little space available for lubrication. An axle center drive with the features of the preamble of claim 1 is, for example, made of DE 34 15 773 A1 known. It is an object of the invention to provide an axle center drive of the type mentioned above, an axle drive with such an axle center drive and a drive axle with such an axle center drive, each of which enables at least two selectable transmission ratios, a compact design and a comparatively simple but reliable lubrication and cooling. The problem is solved by an axle center drive with the features of claim 1, by an axle center drive with the features of claim 2, by an axle drive with the features of claim 10, and by a drive axle with the features of claim 11. Advantageous embodiments are described in the dependent claims, the present description, and the figures. The axle center transmission according to the invention for transmitting a drive torque received from a drive device to two half-shafts of a vehicle axle comprises a transmission for translating a drive torque received at an input element with at least two selectable transmission ratios, and a differential for distributing the translated drive torque to two output elements. An electric motor is preferably used as the drive device. In principle, the two transmission ratios can each result from a higher speed reduction, i.e., a reduction to a lower speed, or a 1:1 reduction. The at least two transmission ratios of the reduction gear are different from each other. In particular, if the drive device from which the axle center transmission receives the drive torque is a high-speed electric motor, the at least two transmission ratios are preferably not a 1:1 or 1:1. Not just a faster translation, but a reduction in at least one of the gear ratios, preferably in all switchable gear ratios. The input element, at which the drive torque is received, then translated by the transmission and output to the differential, can be considered the input element of the transmission and can also simultaneously form an input element of the axle center drive. However, the input element of the transmission and the input element of the axle center drive can also be formed by different components, between which one or more further components, effectively connecting the two input elements, can be interposed. The output elements to which the differential distributes the translated drive torque received from the transmission can be considered output elements of the