JPS6313056B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speed reducer, and particularly to a speed reducer in which the outer ring and the inner ring of the bearing are provided with a width approximately half the bearing width L. The purpose of this is to obtain a speed reducer.

Fig. 5 shows a conceptual diagram of a conventional speed reduction mechanism, in which a hub 2' is arranged around a support block 1', and bearings 5', 5' are connected to the outer periphery of the support block 1' and the inner periphery of the hub 2'. An input rotation shaft 3' is provided on the center line of the support block 1' to allow relative rotation between the support block 1' and the hub 2'. A deceleration mechanism 4' reduces the speed and transmits it to the hub 2'. Bearing 5' is outer ring 5
1', an inner ring 52', balls 53', and a retainer 54'. As the bearing of this conventional speed reducer, a commercially available deep groove ball bearing is generally used, the dimensions of which are standardized and which consist of an outer ring and an inner ring that are substantially equal to the bearing width L. This deep groove ball bearing is equipped with a retainer to sufficiently withstand high-speed rotation, and has a predetermined number of balls to maintain a predetermined load capacity. The number of balls is limited by the holder and due to the installation of the balls. On the other hand, since the speed reducer extracts low-speed rotation, the bearings that allow relative rotation of the support block and hub have sufficient load capacity and may need low durability at high-speed rotation. In such cases, conventional speed reducers use wide, commercially available, expensive bearings that satisfy the load capacity and are used for high-speed rotation, making the speed reducers themselves expensive. Therefore, in the present invention, a reduction gear is obtained that uses a low-speed rotation bearing in which an outer ring and an inner ring having a width approximately half of the bearing width L are combined, and only balls are inserted therein. In this invention, one commercially available bearing material can be used for two
Since they are used individually, the bearings become cheaper and the reducer also becomes cheaper. In addition, since the angular ball bearing is used by combining the outer ring and inner ring of each of the two halves, there is no drop in load capacity.In fact, the number of balls can be reduced because it is easy to incorporate the balls. 50%
It is possible to increase the load capacity of the bearing to approx.
Can be increased by 50%. Therefore, it is possible to provide a reduction gear that can increase the external load acting on the hub or support block.

To explain this invention with reference to the drawings, Fig. 1 shows an example in which the reduction gear of the invention is applied to a traveling drive of a crawler type vehicle, and Fig. 2 shows a cross section taken along line A-A in Fig. 1. ing.

A hydraulic motor 3 is fixed to a frame 1 of a crawler type vehicle, and a speed reducer 5 of the present invention reduces the rotation of the hydraulic motor to drive a sprocket 7 of a traveling drive system with a large output torque. The output shaft 104 of the hydraulic motor 3 (which becomes a part of the input shaft of the reducer shown in FIG. 5) has a bearing 102 mounted on the casing 100 of the hydraulic motor 3 and a rear flange 101 fixedly attached to the rear end surface of the casing. It is rotatably supported by 103. The casing 100 of the hydraulic motor 3 constitutes a support block for the reduction gear 5. As can be seen from FIG. 1 and FIG. 4, which shows only the casing, the casing 100 is
It consists of a disc-shaped part 17 having a recess 17a on the back surface that fits tightly into the main body of the hydraulic motor 3, and a star-shaped column part 19 protruding from the disc-shaped part 17. A casing 100 is attached to the flange portion 17' formed on the disc-shaped portion 17.
A screw hole 17c is formed for bolting the frame 1 to the frame 1 of the crawler vehicle. Furthermore, a center hole 19a into which the output rotating shaft 104 is inserted is provided through the center of the star-shaped column 19. Further, as shown in FIG.
23' and bolts 24. Roller bearings 27 and 29 are mounted on the disc-shaped portion 17 and the end disc 25, respectively, and three crank pins 31 are rotatably supported at both ends between the bearings. The crank pin 31 has two crank parts 31a and 3 which are eccentrically arranged by e with respect to the rotation axis Acd.
1c, and two pinions 33 are fitted into the crank parts 31a and 31c. pinion 33
has external teeth 3 on the outer peripheral surface as shown in Figure 3.
3a, the crank portion 31 of the crank pin 31
a or 31c (FIG. 1) via a bearing 35. Furthermore, a star-shaped groove 33c is formed which extends radially from the center of the pinion 33 and is slightly larger than the star-shaped column part 19 formed on the casing 100.

In FIG. 1, a ball bearing 36 is mounted on the outer periphery of the disc-shaped portion 17 and the end disc 25 of the casing 100.
a and 36b, and rotatably supports the hub 37.

These bearings 36a, 36b are outer rings 36a', 36
b', inner rings 36a'', 3b'', and balls 36c, 36c', and the outer and inner rings of a single deep groove ball bearing are split in half at the center, and one half is used as the outer and inner rings. It is. That is, to further explain FIG. 6, one commercially available deep groove ball bearing 36 consists of an outer ring and an inner ring with a width approximately equal to the bearing width L.
Before assembling the balls, the outer ring 36' and the inner ring 36'' are cut into left and right parts at the center cutting line c and divided into two halves.(The position of the balls is shown by the dotted circle 36c.) ' is the right part 36a', the left part 36b', and the inner ring 36'' is the left part 36
a'' and a right portion 36b''. Outer ring 36
a', 36b' and inner rings 36a'', 36b'' each have a width approximately half of the bearing width L.

In the embodiment shown in FIG. 1, the bearing 36a uses the outer ring portion 36a' shown in FIG. 6 as the outer ring, and the inner ring portion 36a'' shown in FIG. 6 as the inner ring. A bearing is constructed by incorporating balls between the bearings as shown in the illustrated example.

Since the speed of a crawler vehicle (used as a power shovel, etc.) as shown in this example is much lower than that of a general automobile, the hub rotates at a very low speed. It would be extremely uneconomical to use the same bearing as is. In this invention, since the bearing is made up of only an outer ring, an inner ring, and balls having a width approximately half the width of the bearing, the bearing can be made inexpensive, and as a result, an inexpensive reduction gear can be obtained.

The hub 37 drives the drive sprocket 7 of the crawler vehicle, and has a pinion 3 on its inner peripheral surface.
A slightly larger number of small diameter pins 39 than the number of teeth of the external teeth 33a formed on the outer periphery of the tooth 3 form an internal tooth made of a pin gear evenly distributed. Arc groove 3 of hub 37
Between 7' and the pin 39, there is a film of a porous substance that has a high ability to retain oil and a soft, easily deformable, low-friction solid lubricant, and a film of a soft, low-friction solid lubricant. Two phases are deposited with a thickness of about 5 to 30 μm each. As a result, the coefficient of friction between the pin and the hub becomes lower than the coefficient of friction between the pin and the pinion gear, and the pin comes into sliding contact with the hub and rolling contact with the pinion gear. This helps improve engagement efficiency and pin durability.

As shown in FIG.
The rotation of the crank pin 31 causes the central axes of the crank parts 31a and 31c to revolve around the rotation axis of the crank pin 31, causing the two pinions 33 to rotate eccentrically and rotate outwardly. Teeth 33a engage pin gears on hub 37. In FIG. 1, the first external gear 4 is connected to the right end of the output rotation shaft 104 via a coupling ring 200.
1 is spline-coupled at one end, and the toothed portion at the other end is such that its end surface abuts the inner center of the lid 47 via a ball 201. In this way, the first external gear is attached so that it can move slightly in the radial direction. Further, three second external gears 43 having a larger number of teeth than the first external gear 41 are spline-coupled to the right end of the crank pin 31 supported at both ends, and both teeth 41 and 43 are meshed with each other.
The lid 4 is attached to the outside of both gears 41 and 43 by bolts 45.
A floating seal 49 is provided on the outside of a bearing 36a that rotatably supports the hub 37 and prevents leakage of lubricating oil from the reducer 5. The rotation of the output shaft of the hydraulic motor 3 is transmitted through the first external gear 41 to the second external gear 43 that meshes therewith, at a reduced speed according to the ratio of the number of teeth between the two gears 41 and 43. Due to the rotation of the second external gear 43, the crank portion 31a of the crank pin 31, which is rotatably supported at both ends by the casing 100, generates a revolution, and due to this revolution, the pinion 33 engaged with the crank portion 31a via the bearing 35 Eccentrically orbiting. Due to the eccentric revolution of the pinion 33, external teeth 33a formed on the outer periphery of the pinion engage with a pin gear formed on the inner periphery of the hub 37, causing the hub 37 to rotate at a reduced speed. The sprocket 7 attached to the hub 37 drives the traveling system of the crawler vehicle. If there is only one pinion 33, the torque transmitted to the crank pin will pulsate and a negative torque, that is, a torque that obstructs the torque transmission, will occur, reducing efficiency. Therefore, for practical use, two or more pinions are required as shown in the figure. It is necessary to juxtapose the

To explain in more detail the structure and operation of the axial piston type hydraulic motor, in FIG. 1, 103 is a needle roller bearing, 102 is a ball bearing, and the motor output shaft 104 and cylinder block 1
09 is spline connected. piston-
Cylinder assembly 105 is cylinder block 10
9, a two-stage piston 106, and a ball 114, and the ball is connected to the piston by a throttle to the extent that it can rotate. A brake 119 provided between the casing and the rear flange includes a piston 120, a contact plate 121, a friction plate 122, and a spring 123. The plate has a protrusion formed on its outer periphery, which is engaged with a notch formed in the casing.
Although it can move in the axial direction, it cannot rotate. 119' and 119'' are passages that guide pressure oil between the casing 100 and the piston 120 when the brake is released. 124 is a passage that guides the pressure oil led into the cylinder chamber 113 to the circumferential surface of the ball. The ball is guided between the pistons to form an oil film.This makes it easy for the balls to roll and rotate, improving efficiency. Reference numeral 125 designates a spring, which keeps the cylinder block in contact with the timing plate 117. The swash plate 118 has a circular arc groove 126 with a radius of curvature slightly larger than the ball diameter.The slope 116 is driven by a conventional axial piston hydraulic pump or motor. The swash plate 118 corresponds to a retainer plate for holding the shoe in place of the ball of this embodiment on the swash plate, and is provided to always press the piston and ball against the swash plate.The swash plate 118 is attached to the casing 100. It is attached so that it cannot rotate by means of one inserted pin and a spigot part 17'' for positioning in the radial direction.

The pressure shaft flowing into the passage 127 formed in the rear flange passes through the passage 128 in the timing plate 117 and the cylinder block, flows into the cylinder chamber 113, and moves the piston 106 to the swash plate 11.
8. The several pistons defined here are given a component force around the output axis by the inclination of the swash plate surface, so that they rotate together with the cylinder block. The rotation is transmitted to the spline-coupled output shaft and becomes the rotation of the output shaft, which functions as a hydraulic motor. At the same time, the remaining predetermined pistons stroke toward the rear flange side and fill the cylinder chamber 11.
3' flows out through passage 128' within the cylinder chamber, within the timing plate, and through passage 127'.

In the embodiment of the present invention, one outer ring and one inner ring, which are obtained by dividing one commercially available wide bearing into two, are arranged in one of a pair of bearings of one reduction gear. Even if one outer ring is formed by dividing a single bearing into two parts and one inner ring is formed by dividing another commercially available bearing into two parts, this does not depart from the scope of the present invention. In addition, the method of manufacturing an outer ring and an inner ring with a width of about half the width of the bearing can be done by dividing a commercially available wide bearing into two parts, or by specially manufacturing an outer ring and an inner ring with a width of about half the width of the bearing. , none of these shall depart from the scope of the present invention.

The reducer of this invention is equipped with a bearing that combines an outer ring, an inner ring, and balls each having a width approximately half the width of the bearing, and one commercially available bearing material can be used for two, making it inexpensive. This makes the bearings more economical, and the reducer becomes cheaper. In addition, since the angular ball bearing is used by combining the outer ring and inner ring of each of the two halves, there is no drop in load capacity, and in fact, the number of balls can be reduced because it is easy to incorporate the balls. 50%
It is possible to increase the load capacity of the bearing to approximately 50
% can be increased. Therefore, it is possible to provide a reduction gear that can increase the external load acting on the hub or support block.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the reduction gear of the present invention applied to a crawler-type vehicle for traveling drive, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, and Fig. 3 is a perspective view of the pinion. , Figure 4 is a perspective view of the casing, and Figure 5 is a perspective view of the casing.
The figure is a conceptual diagram of a conventional speed reducer, and FIG. 6 is an explanatory diagram showing a divided state of the bearing. Explanation of main symbols, 1...Frame, 3...Hydraulic motor, 36, 36a, 36b...Bearing, 5...Reducer,
36a', 36b'...outer ring, 36a'', 36''...inner ring,
36c, 36c'...Ball, 100...Casing, L...
Bearing width.

Claims (1)

[Scope of Claims] 1. A support block, a hub disposed around the support block, and a hub provided between the outer periphery of the support block and the inner periphery of the hub to allow relative rotation of the support block and hub. In a speed reducer that includes a bearing, an input rotation shaft provided on the center line of a support block, and a reduction mechanism that decelerates the rotation of the input rotation shaft and transmits the rotation to the hub, the bearing has an outer ring, an inner ring, an outer ring, and an inner ring. 1. A speed reducer characterized in that the outer ring and the inner ring have a width that is approximately half the width of the bearing. 2. Claim 1, characterized in that the outer ring and the inner ring are each one of the outer ring and the inner ring of a single bearing which is divided into two halves, each consisting of an outer ring and an inner ring having a width substantially equal to the width of the bearing. The speed reducer mentioned.