Differential with differential gear and drive gear

Abstract

The invention relates to a differential having differential gears (4, 5) and a drive gear (2), the drive gear (2) comprising a tooth system (3) running around an axis of rotation on the outside of the winding side and the differential gears (4, 5) being rotatably mounted in the drive gear (2), the differential gears (4, 5) rotating together on a journal (7). In the case of a differential with reduced production costs, guide elements (16, 17) designed as planar guide surfaces are arranged between the differential gears (4, 5) and the drive gear (2) in the axial extension direction of the journal (7).

Description

Field of the Invention

[0001] The present invention relates to a differential having a differential gear and a drive gear, wherein the drive gear includes a tooth system that runs around a rotational axis on the orbiting side, and the differential gear is rotatably mounted in the drive gear, wherein the differential gears rotate together on a journal. Background Art

[0002] DE 10 2018 124 491 A1 discloses a differential having a differential gear, a drive gear, and at least one cover. The drive gear has a tooth system that runs around a rotational axis on the orbiting side and has a support point on the inner side. Lugs of a journal on which the differential gear is mounted engage in the support point. Thus, the differential gear is rotatably mounted in the drive gear.

[0003] DE 10 2020 113 361 A1 shows a housing for a transmission device that houses a bevel gear differential. The housing includes a first housing part made of sheet metal and a second housing part made of sheet metal. At least one lug projects from the first housing part and is formed as one piece with the first housing part and extends through a corresponding opening formed in the second housing part. In this case, the projecting of the lug beyond the free end of the second housing part is plastically deformed such that the first housing part is firmly connected to the second housing part.

[0004] DE 10 2009 055 867 A1 shows a differential having at least one drive gear, at least two axle wheels, at least one differential gear, and at least one connecting element, wherein the connecting element is subjected to at least a first torque from the drive gear and the connecting element transfers at least a second torque to at least one of the at least two axle wheels. The present invention includes the fact that the drive gear is designed such that the drive gear at least partially encloses at least one internal space and the connecting element is at least partially arranged in the internal space at least partially enclosed by the drive gear.

[0005] DE 10 2015 220 518 A1 shows a differential gear device which, in particular with respect to such a differential gear device provided with a pair of side gears and a covering part, distributes the torque of a drive element rotatable together with a pinion carrier part to a pair of output shafts. The pair of side gears have a tooth system on their outer circumference, in which pinions engage, and each of the pair of side gears is connected to one of the output shafts. The covering part covers at least one of the side gears on the outside and rotates as a unit with the drive element. And wherein, even under severe operating conditions such as when the pinions rotate at high speed, the sliding parts of the pinions and the parts of the pinions in which the side gears engage are sufficiently supplied with lubricating oil, and jamming of the sliding parts and the meshing parts with each other is effectively prevented. At least one of the covering parts is provided with an oil holding part covering the back of the side gear in a first specific area, the first specific area includes an area overlapping with the pinions when viewed from the outside in the axial direction of the output shaft, and at least one of the covering parts is provided with a cutout exposing the back of the side gear in a second specific area, and the second specific area does not overlap with the pinions. Summary of the Invention

[0006] The present invention is based on the following object: to provide a differential with a differential gear and a drive gear with reduced production costs.

[0007] This object is achieved by the subject matter of claim 1.

[0008] The differential explained at the beginning has a differential gear and a drive gear, wherein the drive gear includes a tooth system running around a rotation axis on the outside of the orbiting side, and the differential gear is rotatably mounted in the drive gear, wherein the differential gears rotate together on a journal. In this differential, a guiding element configured as a planar guiding surface is arranged between the differential gear and the drive gear in the axial extension direction of the journal. To form such a differential, only one tool is required to form the components adjacent to the guiding surface, in particular the drive gear. This reduces production and assembly costs.

[0009] According to the invention, the axially outwardly directed end face of the differential gear is configured as a planar guiding surface. This allows for the elimination of a separate guiding element, which further reduces production costs.

[0010] According to the invention, the journal is mounted in a radially extending groove in the body of the drive gear, wherein the planar guiding surface engages in a recess in the body of the drive gear surrounding the groove. The recess can be formed together with the groove in the body of the drive gear using one tool. This can be done by milling and grinding or by broaching. In the case of possible hard machining, there is no interrupted cutting.

[0011] According to another embodiment, a separate disk-shaped member is arranged between the differential gear and the drive gear as a planar guiding surface. This separate disk-shaped member allows for precise adjustment of the differential gear relative to the drive gear.

[0012] According to another embodiment, the separate disk-shaped member has a coating. This coating improves the emergency running characteristics of the differential.

[0013] According to another embodiment, the differential gear engages with the drive gear and is mounted to be rotatable about its own axis. This ensures that the differential gear has an axis of rotation perpendicular to the axis of rotation of the drive gear and enables the differential gear to approach the driven gear within a small installation space.

[0014] According to another embodiment, a journal that axially extends and protrudes beyond the planar guiding surface of the differential gear is mounted in a groove such that the journal is mounted in the circumferential direction about the axis of rotation of the differential gear. This improves the assembly accuracy, which has a particularly positive effect on the accuracy of the tooth contact between the differential gear and the driven gear. Description of the Drawings

[0015] The present invention permits multiple embodiments. One of the multiple embodiments is explained in more detail using the figures shown in the drawings.

[0016] In the drawings:

[0017] Figure 1 An exemplary embodiment of a differential according to the present invention is shown;

[0018] Figure 2 An exemplary embodiment of a drive gear is shown;

[0019] Figure 3 An exemplary embodiment of a differential gear / driven gear unit is shown. Detailed Description

[0020] In Figure 1In the figure, an exemplary embodiment of a differential according to the present invention is shown in an overall view. The differential 1 includes a drive gear 2 and two differential gears 4, 5. The drive gear has a tooth system 3 configured as a positive helical tooth system. The two differential gears are engaged in two driven gears 6 arranged between the two differential gears. Only one of the driven gears 6 is shown. The differential gears 4, 5 and the driven gear 6 are configured as bevel gears. The differential speed on the wheels is compensated by the combination of the differential gears 4, 5 and the driven gear 6. For this purpose, the wheels are meshed with the driven gear 6 and mounted on the drive gear 2 so as to be able to rotate about the rotation axis of the wheels themselves. The differential gears 4, 5 are each mounted in grooves 8, 9 of the drive gear 2 via journals 7 extending radially in the drive gear 2. The grooves 8, 9 form support points for the journals 7, and the journals are rotatably seated in the grooves 8, 9.

[0021] Figure 2 An exemplary embodiment of the drive gear 2 used as shown in Figure 1 is shown. The drive gear 2 is the main shaft of the differential, and the power from the vehicle drive is introduced into the differential via this main shaft and distributed from the differential to the wheels. The drive gear 2 has a body 10 which has a central opening 11 for receiving Figure 3 the differential gear / driven gear unit 18 shown in. Inside the opening 11 of the drive gear 2, two radial grooves 8, 9 are formed opposite to each other. Each groove 8, 9 is surrounded by recesses 12, 13, whereby the grooves 8, 9 protrude beyond the recesses 12, 13. The grooves 8, 9 and the recesses 12, 13 can be easily formed by broaching, milling and grinding using tools.

[0022] The bases 14, 15 of the recesses 12, 13 represent the first planar surfaces on which the end faces 16, 17 of the differential gears 4, 5 rest. The axially outwardly oriented end faces 16, 17 of the differential gears 4, 5 are also planar and form another planar guiding surface, which ensures a high-precision fit with the recesses 12, 13. The dimensions of the recesses 12, 13 are adapted to the dimensions of the end faces 16, 17.

[0023] In an alternative, the flat end faces 16, 17 of the differential gears 4, 5 are replaced by flat disk-shaped parts which are engaged in the recesses 12, 13 and thus form flat guiding surfaces.

[0024] List of reference numerals

[0025] 1 Differential

[0026] 2 Drive gear

[0027] 3 Tooth system of the drive gear

[0028] 4 Differential gear

[0029] 5 Differential gear

[0030] 6 Driven gear

[0031] 7 Journal

[0032] 8 Groove

[0033] 9 Groove

[0034] 10 Body of driving gear

[0035] 11 Opening of driving gear

[0036] 12 Recess

[0037] 13 Recess

[0038] 14 Base of recess

[0039] 15 Base of recess

[0040] 16 End face of differential gear

[0041] 17 End face of differential gear

[0042] 18 Differential gear / driven gear unit

Claims

1. A differential having differential gears (4, 5) and a drive gear (2), wherein, the drive gear (2) has a tooth system (3) running around a rotation axis on the outside of the driven side, and the differential gears (4, 5) are rotatably mounted in the drive gear (2), wherein the differential gears (4, 5) rotate together on a journal (7), characterized in that guide elements (16, 17) configured as planar guide surfaces are arranged between the differential gears (4, 5) and the drive gear (2) in the axial extension direction of the journal (7), wherein the axially outwardly directed end faces (16, 17) of the differential gears (4, 5) are configured as planar guide surfaces, and the journal (7) is in each case mounted in radially extending grooves (8, 9) of the body (10) of the drive gear (2), and the planar guide surfaces (16, 17) engage in radially recessed portions (12, 13) of the body (10) surrounding the grooves (8, 9), and the recessed portions (12, 13) and the grooves (8, 9) are formed on the body (10) of the drive gear (2) using a single tool.

2. The differential according to claim 1, characterized in that, a separate disk-shaped part is arranged between the differential gears (4, 5) as a planar guide surface.

3. The differential according to claim 2, characterized in that, the separate disk-shaped part has a coating.

4. The differential according to at least any one of the preceding claims, characterized in that, the differential gears (4, 5) engage with the drive gear (2) and are mounted so as to be rotatable about their own rotation axes.

5. The differential according to at least any one of the preceding claims, characterized in that, the journal (7) radially extending into the drive gear (2) and protruding beyond the planar guide surfaces (16, 17) of the differential gears (4, 5) is mounted in the grooves (8, 9) such that the journal (7) is mounted in the circumferential direction about the rotation axis of the differential gears (4, 5).

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