Planet carrier

Abstract

The present invention provides a planet carrier, which comprises a main planet carrier and a planet carrier end cover formed separately, wherein the planet carrier end cover comprises an end cover body and a toothed portion located on the outer periphery of the end cover body, and the planet carrier end cover is connected to the main planet carrier in a relatively rotation-resistant manner by means of interference fit, spline connection and / or welding. The planet carrier according to the present invention has a parking lock function and has a compact structure and low manufacturing cost.

Description

Technical Field

[0001] The present invention relates to a planetary reduction and differential system of a vehicle, in particular to a planetary reduction and differential system integrating a planetary gear set and a lightweight differential, and more particularly to a planetary carrier integrating parking gears. Background Art

[0002] Reference Figure 1 A known planetary reduction and differential system in the prior art integrates a planetary gear set and a lightweight differential. The planetary carrier of the planetary gear set includes a main planetary carrier 1 and a planetary carrier end cover 2, and the planetary carrier end cover 2 is usually fixed to one end of the main planetary carrier 1 by screws.

[0003] The above-mentioned planetary reduction and differential system does not have a parking lock function. When a parking lock function needs to be added to the vehicle, related components need to be arranged in an additional space.

[0004] CN108167424A discloses a planet carrier with integrated parking gear, which is formed into a single-piece structure by casting, and the planet carrier includes a planet wheel mounting portion and a parking gear portion. Since the entire planet carrier is formed into a single-piece structure, the gear portion needs to be made of a material with higher strength, which increases the manufacturing cost of the entire planet carrier. Summary of the invention

[0005] The object of the present invention is to overcome or at least alleviate the above-mentioned deficiencies in the prior art and to provide a planet carrier with integrated parking gears.

[0006] According to the present invention, the planet carrier comprises a main planet carrier and a planet carrier end cover which are formed separately, wherein the planet carrier end cover comprises an end cover body and a tooth portion located at the outer periphery of the end cover body.

[0007] The planet carrier end cover is connected to the main planet carrier in a relatively rotationally-resistant manner by means of interference fit, spline connection and / or welding.

[0008] In at least one embodiment, the axial thickness of the tooth portion is greater than the axial thickness of the end cover body.

[0009] In at least one embodiment, the tooth portion protrudes axially from an end surface of the end cover body facing the main planet carrier.

[0010] In at least one embodiment, the outer periphery of the main planet carrier is connected to the inner periphery of the gear portion by interference fit.

[0011] In at least one embodiment, an outer periphery of the main planet carrier is connected to an inner periphery of the gear portion via a spline.

[0012] In at least one embodiment, the main planet carrier and the planet carrier end cover are further axially connected by bolts or screws.

[0013] In at least one embodiment, an outer periphery of the main planet carrier is welded to an inner periphery of the gear portion.

[0014] In at least one embodiment, the material strength of the planet carrier end cover is higher than the material strength of the main planet carrier.

[0015] In at least one embodiment, the main planet carrier is a casting, and the planet carrier end cover is a forging.

[0016] In at least one embodiment, the main planet carrier is made of ductile iron, and the planet carrier end cover is made of low carbon steel.

[0017] The present invention provides a planet carrier with integrated parking gears. The planet carrier according to the present invention has a parking lock function.

[0018] Since the main planet carrier and the planet carrier end cover with the toothed portion are formed separately, the two can be made of different materials and / or using different processes, which can achieve low manufacturing costs while ensuring their respective functions.

[0019] Since the planet carrier end cover is connected to the main planet carrier in a relatively rotationally resistant manner by interference fit, spline connection and / or welding, the connection strength between the planet carrier end cover and the main planet carrier is high, and a large circumferential force can be transmitted therebetween. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of an existing planetary reduction and differential system.

[0021] Figure 2 is a schematic diagram of a planetary reduction and differential system according to one embodiment of the present invention.

[0022] Figure 3 yes Figure 2 Cross-sectional view of the planet carrier in FIG.

[0023] Description of reference numerals:

[0024] 1 main planet carrier; 2 planet carrier end cover; 201 end cover body; 202 gear part. DETAILED DESCRIPTION

[0025] The exemplary embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present invention, and are not intended to exhaust all feasible ways of the present invention, nor to limit the scope of the present invention. In the present invention, unless otherwise specified, "axial" refers to the direction parallel to the central axis of the main planet carrier 1, "radial" refers to the radial direction of the main planet carrier 1, and "circumferential" refers to the circumferential direction of the main planet carrier 1.

[0026] Reference Figure 2-3 , introduces the planetary carrier with integrated parking gear in the planetary reduction and differential system of the present invention.

[0027] The planet carrier comprises a main planet carrier 1 and a planet carrier end cover 2. The main planet carrier 1 has a substantially cylindrical peripheral wall, which at least partially accommodates the sun gear and the planet gears in an internal cavity. The planet carrier end cover 2 is connected to the axial end of the main planet carrier 1 in a relatively rotationally fixed manner.

[0028] The planet carrier cover 2 includes a cover body 201 and a toothed portion 202 located on the outer periphery of the cover body 201. The toothed portion 202 can withstand circumferential force and function as a parking gear. Figure 3 , the tooth portion 202 protrudes from the end face of the end cover body 201 facing the main planetary carrier 1, and the axial thickness of the tooth portion 202 is greater than the axial thickness of the end cover body 201. The above structure of the tooth portion 202 not only ensures that the planetary carrier end cover 2 has sufficient thickness to achieve sufficient strength when used as a parking gear, but also makes it easier for the main planetary carrier 1 and the planetary carrier end cover 2 to achieve relative rotation resistance connection. It should be understood that, without interfering with other components, the tooth portion 202 can also protrude from the end face of the end cover body 201 away from the main planetary carrier 1 to increase the axial thickness of the tooth portion 202. Of course, the tooth portion 202 protruding axially from the end face of the end cover body 201 facing the main planetary carrier 1 is more conducive to saving system space.

[0029] In this embodiment, the main planet carrier 1 and the planet carrier end cover 2 are connected by interference fit, that is, the outer diameter of the main planet carrier 1 is slightly larger than the inner diameter of the planet carrier end cover 2 at the tooth portion 202. This interference fit allows sufficient torque to be transmitted between the main planet carrier 1 and the planet carrier end cover 2.

[0030] In other embodiments, the main planet carrier 1 and the planet carrier end cover 2 may also be connected in other ways. For example, a spline is provided between the main planet carrier 1 and the gear portion 202, or the main planet carrier 1 and the planet carrier end cover 2 are welded together. It should be understood that when a welding connection method is used, the welding position is preferably, but not limited to, between the outer periphery of the main planet carrier 1 and the inner periphery of the gear portion 202; for example, the welding position may also be between the two opposite end faces of the main planet carrier 1 and the end cover body 201. In this case, the gear portion 202 may not protrude from the end face of the end cover body 201 facing the main planet carrier 1, provided that the gear portion 202 has sufficient axial thickness.

[0031] It should be understood that the connecting screws in the prior art can still be retained between the main planet carrier 1 and the planet carrier end cover 2 to transmit the axial force.

[0032] Since the structure of the main planet carrier 1 is relatively complex and it does not need to bear a large circumferential force, preferably, the main planet carrier 1 is cast using ductile iron. The main planet carrier 1 manufactured in this way has a simple manufacturing process and low cost.

[0033] Since the tooth portion 202 of the planet carrier end cover 2 needs to withstand a large circumferential force, the material strength of the planet carrier end cover 2 is preferably higher than that of the main planet carrier 1. Preferably, the planet carrier end cover 2 is forged using low carbon steel and combined with a machining forming method when necessary. The planet carrier end cover 2 manufactured in this way has high strength and can meet the strength requirements when it performs the parking gear function.

[0034] The above embodiments of the present invention can achieve one or more of the following advantages:

[0035] (i) The parking gear portion 202 is integrated on the planet carrier, so that the planetary reduction and differential system has a parking lock function.

[0036] (ii) The tooth portion 202 is integrated into the outer periphery of the planet carrier cover 2, saving space.

[0037] (iii) Since the structure of the main planet carrier 1 is relatively complex, while the structure of the planet carrier end cover 2 is simple, and the tooth portion 202 needs to withstand a large circumferential force and has high requirements on material strength, the main planet carrier 1 and the planet carrier end cover 2 are manufactured separately and the tooth portion 202 is integrated into the planet carrier end cover 2. In this way, the planet carrier end cover 2 can be manufactured with a higher strength material instead of the main planet carrier 1 or the entire planet carrier, so that the planet carrier end cover 2 integrated with the tooth portion 202 can withstand a large circumferential force; at the same time, the main planet carrier 1 with a complex structure is manufactured with a lower strength material and a process that is easier to form. Compared with the solution of manufacturing a planet carrier with integrated parking gears in an integrated manner or integrating the parking gears into the main planet carrier 1, this not only saves material costs but also reduces process difficulty.

[0038] (iv) The planet carrier end cover 2 is connected to the main planet carrier 1 in a relatively rotationally-resistant manner by interference fit, spline connection and / or welding, so that the connection strength between the planet carrier end cover 2 and the main planet carrier 1 is high and a large circumferential force can be transmitted therebetween.

[0039] (v) The main planet carrier 1 and the planet carrier end cover 2 are connected by interference fit or welding, so that the support stiffness of the planet carrier formed by the two is increased, which helps to reduce the noise, vibration and harshness (NVH) of the system.

[0040] It should be understood that the above embodiments are only exemplary and are not intended to limit the present invention. Those skilled in the art may make various modifications and changes to the above embodiments under the guidance of the present invention without departing from the scope of the present invention.

Claims

1. A planet carrier, comprising a main planet carrier and a planet carrier end cover formed separately, wherein: The planet carrier end cover comprises an end cover body and a tooth portion located on the outer periphery of the end cover body, the axial thickness of the tooth portion is greater than the axial thickness of the end cover body, and the tooth portion protrudes axially only from the end surface of the end cover body facing the main planet carrier, The planet carrier end cover is connected to the main planet carrier in a relatively rotationally resistant manner by means of interference fit, spline connection and / or welding. The material strength of the planet carrier end cover is higher than that of the main planet carrier. The main planet carrier is a casting, and the planet carrier end cover is a forging. The main planet carrier is made of ductile iron, and the planet carrier end cover is made of low carbon steel.

2. The planet carrier according to claim 1, characterized in that: The outer periphery of the main planet carrier is connected to the inner periphery of the gear portion through interference fit.

3. The planet carrier according to claim 1, characterized in that: The outer periphery of the main planet carrier and the inner periphery of the gear portion are connected via splines.

4. The planet carrier according to claim 3, characterized in that: The main planet carrier and the planet carrier end cover are also axially connected by bolts or screws.

5. The planet carrier according to claim 1, characterized in that: The outer periphery of the main planet carrier is welded to the inner periphery of the gear portion.

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