JPH04312247A - Planetary gear mechanism - Google Patents

Abstract

PURPOSE:To miniaturize, and to reduce the weight of a planetary gear mechanism such as a differential mechanism by constituting it so as to be made up of an internal gear and a sun gear which are coaxially arranged, pinion gears connecting these gears, and a pinion carrier having housing chambers in which the pinion gears are housed and rotatably supported by the tooth crest parts thereof. CONSTITUTION:A differential mechanism 47 (planetary gear mechanism) arranged inside the differential gear case 21 of a rear differential gear 7 is made up of an internal gear 49, pinion gears 51 on the outer side, pinion gears 53 on the inner side, and a sun gear 55. The internal gear 49 is formed in the differential gear case 21, and the sun gear 55 is formed in the hub 39 on the left side. And the pinion gears 51, 53 are housed in the cylindrical housing chambers 59 with a partially cutout part which have been provided in a pinion carrier 57, and the respective gears 51, 53 are rotatably supported inside the carrier 57 in such a way that the tooth crest parts 61, 63 of the respective gears 51, 53 slidingly move along the wall surface of the housing chamber 59.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear mechanism used in a differential mechanism or the like.

0002

2. Description of the Related Art FIG. 4 shows a conventional planetary gear type differential device. This is a single pinion type, with internal gear 201 and sun gear 2.
03 are connected by the same pinion gear 205.

[0003] Furthermore, a differential device is described in Japanese Patent Publication No. 46-3407. Compared to a normal planetary gear type device, this device does not have an internal gear, but instead has a pair of sun gears and two sets of pinion gears. Each set of pinion gears is rotatably stored in a cylindrical storage chamber provided in a pinion carrier with each set offset in the axial direction, and
Each pair meshes with each other at the axially overlapping parts. or,
The sun gear is formed into a pair of output shafts, which are specifically meshed with a pinion gear set on each side. An input ring gear is fixed to the pinion carrier, and rotation of the pinion carrier is divided from each pinion gear set to each output shaft, and differentially distributed to each output shaft by rotation of the pinion gear.

0004

However, in the former case, the pinion carrier 207 is constructed by welding two members 209 and 211 that support the pinion gear at both ends, making the structure and assembly complicated. together with pinion gear 2
05 cannot be replaced without destroying the pinion carrier 207. Further, the pinion gear 205 is supported on the shaft 213, and both ends of the shaft 213 must be crimped to the pinion carrier 207 to prevent it from rotating and coming off, and the assembly of the pinion gear 205 is thus complicated. be. In addition, a differential limiting device such as a viscous coupling or a differential lock device is required to provide sufficient differential limiting for practical purposes.

In the latter case, the pinion carrier is of integral construction, and the pinion gear can be easily assembled by simply storing it in the storage chamber of the pinion carrier. Further, since the friction of the pinion gear occurs in its outer shape, a large differential limiting force can be obtained, and a differential limiting mechanism is not required.

However, due to the special configuration that uses a pair of sun gears and two pinion gear sets without using an internal gear, it becomes necessary to offset the pinion gear sets, resulting in a wide axial width, which makes the differential The device and the differential case that houses it become large and heavy.

Therefore, the present invention has a pinion carrier structure and a pinion gear that are easy to assemble and replace, can obtain a large differential limiting force without using a special differential limiting device, are narrow in width, and are therefore compact. The purpose is to provide a planetary gear mechanism that can be lightweight.

[0008]

[Means for Solving the Problems] The planetary gear mechanism of the present invention includes an internal gear and a sun gear that are coaxially arranged, one or more pinion gears that connect these gears, or two or more pinion gears that mesh with each other, and a pinion gear that connects these gears. and a pinion carrier having a storage chamber that stores the pinion and rotatably supports the pinion at its tooth tip.

[0009]

[Operation] Unlike the conventional structure in which a pair of sun gears and two pinion gear sets are used and the gear sets are meshed with each other, there is no need to offset the pinion gears, so the width can be narrowed. Since the pinion carrier is not configured to support both ends of the pinion gear, it can be integrated, and mounting of the pinion gear is extremely simple, as it is simply stored in the storage chamber. Further, since friction occurs at the tips of the teeth when the pinion gear rotates, a large differential limiting force can be obtained due to the rotational resistance.

0010

[Embodiment] One embodiment will be explained with reference to FIGS. 1 to 3. Figure 1 shows an example used in a differential device,
Figure 3 shows the power system of a vehicle using this device. Hereinafter, the left and right directions are the left and right directions in this vehicle and in FIG. 1, and the upper part of FIG. 1 corresponds to the front of this vehicle (the upper part of FIG. 3).

First, the configuration of this power system will be explained with reference to FIG.

This power system includes an engine 1, a transmission 3, a propeller shaft 5, a rear differential 7 (a differential device in the embodiment used on the rear wheel side), and rear wheel axles 9, 1.
1. It is composed of left and right rear wheels 13, 15, left and right front wheels 17, 19, etc.

Next, the rear differential 7 will be explained.

A differential case 21 of the rear differential 7 is supported within a differential carrier 23 via a bearing. As shown in FIG. 3, a ring gear 25 is fixed to the differential case 21, and the ring gear 25 meshes with a drive pinion gear 27. The drive pinion gear 27 is integrally formed at the rear end of a drive pinion shaft 29 connected to the propeller shaft 5 side. In this way, the rotation of the engine 1 rotates the differential case 21 from the transmission 3 via the propeller shaft 5.

The differential case 21 is provided with through holes 31, 33 and spiral oil grooves 35, 37 on the inner periphery of the left and right cylindrical portions. Lubricating oil is injected into the differential carrier 23, and this lubricating oil flows through these through holes 31, 33 and oil grooves 35.
, 37 into and out of the differential case 21.

Inside the differential case 21 are left and right hubs 39.
, 41 are coaxially arranged, the left hub 39 being splined to the left rear axle 9, and the right hub 41 splined to the right rear axle 11. Washers 43 and 45 are arranged between the left hub 39 and the differential case 21 and the right hub 41, respectively.

A differential mechanism 47 (
A planetary gear mechanism) is installed. Differential mechanism 4
7 includes an internal gear 49, an outer pinion gear 51, an inner pinion gear 53, and a sun gear 55, which mesh in this order. The internal gear 49 is formed on the differential case 21, and the sun gear 55 is formed on the left hub 39.

As shown in FIG. 2, the pinion gears 51 and 53 are housed in cylindrical storage chambers 59 and 59 provided in the pinion carrier 57 and partially cut out. The gears 51 and 53 are connected to the carrier 57 by sliding the tooth tips 61 and 63 on the wall surface of each storage chamber 59.
It is rotatably supported. Further, each gear 51, 53 is provided with oil holes 65, 65, and the lubricating oil that flows into the differential case 21 lubricates the meshing and sliding parts of each gear, and a portion is retained in these oil holes 65. is supplied to these lubrication points.

The pinion carrier 57 is formed integrally with the right hub 41, and a washer 67 is disposed between the carrier 57 and the differential case 21, and each pinion gear 51
, 53 and the differential case 21 is a washer 6.
9 is placed.

The rear differential 7 is thus constructed.

In the rear differential 7, unlike the conventional example, there is no need to offset the pinion gears 51 and 53, so the width is narrower, and the rear differential 7 and the differential carrier 23 can be made smaller and lighter in the axial direction.

Further, since the pinion carrier 57 does not support the pinion gears 51, 53 at both ends thereof, it can be constructed of one member unlike the conventional example, and therefore it is easy to process and the width can be further reduced.

The pinion gears 51, 53 can be assembled to the pinion carrier 57 very simply by simply storing them in the storage chamber 59, and each gear 51, 53 can be replaced without destroying the pinion carrier 57. Furthermore, since each gear 51, 53 is not supported by a shaft, it is possible to provide an oil hole 65 in the center, which is advantageous for weight reduction.

When the pinion gears 51 and 53 rotate, rotational resistance occurs due to frictional resistance with the wall surface of the storage chamber 59. Sliding friction occurs at each tooth tip portion 61, 63, and since the diameter of the sliding portion is large, a correspondingly large rotational resistance can be obtained.

Next, the function of the rear differential 7 will be explained.

[0026] Differential case 21 (internal gear 49)
The rotation is transmitted from each pinion gear 51, 53 to the pinion carrier 57 (hub 41) and sun gear 55 (hub 39), and is transmitted to the left and right rear wheels 13, 15 via the hubs 39, 41.
is transmitted to.

When a drive resistance difference occurs between the rear wheels 13 and 15, the sun gear 55 and pinion carrier 57 differentially rotate due to the rotation and revolution of each pinion gear 51 and 53, and the driving force of the engine 1 is applied to the rear differential 7. Through the left and right rear wheels 13,
15 differentially distributed.

As described above, due to the large rotational resistance generated in the pinion gears 51 and 53, the rear differential 7 can obtain sufficient differential limiting force without using a differential limiting device such as a viscous coupling or a differential lock device. Since the frictional resistance of the sliding friction portion is proportional to the engine torque, the differential limiting force of the rear differential 7 increases as the engine torque increases.

Therefore, in the vehicle shown in FIG. 3, the differential movement between the rear wheels 13 and 15 is greatly restricted by the rear differential 7 during acceleration or when climbing a slope, thereby improving straight-line stability. Generally, when turning without significant acceleration, the differential limiting force of the rear differential 7 is reduced, allowing smooth turning. Furthermore, even if one rear wheel spins on a rough road, driving force is sent to the other rear wheel via the rear differential 7 due to differential limiting force, thereby maintaining high running performance.

Since the rear differential 7 has a narrow width and does not require a special differential limiting device, the rear differential 7 and the differential carrier 2
It is possible to make it smaller and lighter compared to 3, and the weight of the vehicle can be reduced accordingly.

[0031] Furthermore, in this invention, since the pinion gear does not have a shaft portion that would be a dimensional restriction when reducing the diameter,
It is easy to reduce the diameter of the pinion gear and increase the number of circumferential arrangements or the number of locations in each gear train (consisting of gears 51 and 53).

[0032]

[Effects of the Invention] The planetary gear mechanism of the present invention is configured such that the pinion gear that connects the internal gear and the sun gear is housed in the storage chamber of the pinion carrier, and is rotatably supported by its tooth tips. Therefore, there is no need to offset the gears, the width can be narrowed, and the overall size and weight can be reduced. In addition, the pinion carrier has an easy-to-process integrated structure, making it easy to assemble and replace the pinion gear. or,
Sufficient differential limiting force can be obtained without using a special differential limiting device, which also contributes to size reduction.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of one embodiment.

FIG. 2 is a sectional view taken along line AA in FIG. 1;

FIG. 3 is a skeleton structural diagram showing a power system of a vehicle using this embodiment.

FIG. 4 is a conventional example.

[Explanation of symbols]

49 Internal gear 51, 53 Pinion gear 55 Sun gear 57 Pinion carrier 59 Storage room 61, 63 Tooth tip

Claims (1)

[Claims] Claim 1: An internal gear and a sun gear that are coaxially arranged, one or more pinion gears that connect these gears, or two or more pinion gears that mesh with each other, and the pinion gear is housed and rotatably supported by its tooth tips. A planetary gear mechanism characterized by comprising a pinion carrier having a storage chamber.