JPS6347521A - Power transmission gear - Google Patents

Abstract

PURPOSE:To reduce loss torque and ensure the strength of thrust by providing an angular ball bearing for transmitting increased and reduced speeds between a first and a second rotary shafts, a rolling element holder in between the outer and inner races of said bearing, and a resilient member for energizing the back of said outer race to apply pre-load to said ball bearing. CONSTITUTION:When a second rotary shaft 40 serves as an input shaft and a first rotary shaft 10 as an output shaft, as the shaft 40 and a holder 34 are rotated, rolling elements 33 is rotated by means of the holder 34, power is transmitted to an inner race 31 which is in pressure contact with the rolling element 33 and to the shaft 10, and the rotating speed of the shaft 40 is increasedly transmitted to the shaft 10. In this case, since the rolling elements 33 which have has a spherical shape will not cause a shewing phenomenon, the loss torque of power transmission is the minimum. On the contrary, when the shaft 10 serves as an input shaft and the shaft 40 as an output shaft, the rotating speed of the shaft 10 is reducedly transmitted to the shaft 40. And, the spherical and solid rolling elements of an angular ball bearing ensure strength against a thrust load from the shaft 10 and the shaft 40.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a power transmission device used as a speed reducer or speed increaser that reduces or speeds up and transmits power between two rotating shafts. It is used in spinning machines, machine tools, etc.

<Prior art> Figures 3 and 4 show this type of conventional power transmission device.
This will be explained with reference to the figures.

In the power transmission device on the park side, the speed reduction section or the speed increase section thereof is constituted by the planetary mechanism 1.

This planetary mechanism 1 is interposed between a first rotating shaft 2 and a housing 3 that covers it, and includes a sun wheel 1a fixed to the shaft end of the first rotating shaft 2, and a sun wheel 1a fixed to the shaft end of the first rotating shaft 2. A fixed ring 1b fixed to the housing 3 so as to be concentric with the sun ring 1a, and a plurality of cylindrical planetary shafts 1c equally spaced on the circumference between the fixed ring 1b and the solar ring 1a. .

Each planetary ring 1c is interposed between the sun ring 1a and the fixed ring 1b in a press-contact state.

Further, a plurality of planetary shafts 4a at the shaft ends of the second rotating shaft 4 are fitted into each of the planetary wheels 1c via floating pushers ld. Note that the diameter of the aX axis 4a is the same as that of the planetary axis I.
It is smaller than the diameter of the hollow part of C, and the floating bush 1
Since the diameter of d is also smaller than the diameter of the hollow portion, the planetary shaft 4a is loosely fitted to the planetary ring IC.

In addition, the code|symbol 5 is a rolling bearing which supports the 2nd rotating shaft 4.

In such a power transmission device, when the second rotating shaft 4 is used as the input shaft and the first rotating shaft 2 is used as the output shaft, the planetary mechanism 1 increases the rotation speed of the second rotating shaft 4 to increase the rotation speed of the second rotating shaft 4. However, conversely, if the first rotating shaft 2 is used as the input shaft and the second rotating shaft 4 is used as the output shaft, the planetary mechanism 1 reduces the rotation speed of the first rotating shaft 2 and 2, the signal is transmitted to the rotating shaft 4.

<Problems to be Solved by the Invention> However, the conventional example having such a configuration has the following problems.

In the planetary mechanism 1, since the planetary ring IC has a cylindrical shape, the directionality is determined so that the planetary ring IC rotates in a direction perpendicular to the axial direction of the planetary shaft 4a. Since 4a is loosely fitted, especially 6
High-speed rotation of more than 10,000 rpm often causes a phenomenon called skew. This phenomenon means that the rotational movement direction of the planetary shaft 1c, which should be perpendicular to the axial direction of the planetary shaft 4a, is slightly tilted as shown in FIG.

If this skew occurs, not only will loss of torque increase, but also repair work will have to be performed because the planetary wheels 1c will not automatically return to their normal positions.

In addition, since the planetary shaft 1c is hollow, it is weak in terms of strength, and the planetary ring IC is interposed between the sun wheel 1a and the fixed wheel 1b in a press-contact state, so there is a risk of breakage.
It has a short lifespan.

Furthermore, since the planetary shaft IC has a cylindrical shape, it is pointed out that the structure is weak against thrust loads.

The present invention has been made in view of these circumstances, and aims to reduce torque loss, further improve rigidity, and ensure strength against thrust loads.

<Means for Solving the Problems> In order to achieve the above object, the present invention has the following configuration.

That is, the power transmission device according to the present invention is arranged between a first rotating shaft and a housing that covers the outer periphery thereof, and between the first rotating shaft and a second rotating shaft disposed coaxially therewith. an angular contact ball bearing that transmits power by decelerating or increasing the speed; a retainer that holds a plurality of rolling elements interposed in pressure contact between an inner ring and an outer ring of the angular contact ball bearing; and the second rotating shaft. and a resilient member that biases the back surface of the outer ring to apply preload to the angular ball bearing.

Note that this also includes a case in which the retainer and the transmission member are integrally formed with the second rotating shaft.

Effect〉 The effects of the configuration of the present invention are as follows.

The pressing force of the rolling elements against the outer ring and the inner ring, which is necessary for power transmission, is ensured by the biasing force of the elastic member against the outer ring.

Since the speed reduction section or speed increase section is an angular contact ball bearing, and its rolling elements are spherical and non-directional, the phenomenon of skew does not occur.

Since the rolling elements of the angular contact ball bearing are spherical and solid, they have superior rigidity compared to conventional planetary rollers having hollow sections, and also ensure strength against thrust loads.

<Example> Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 and 2 show one embodiment of the invention.

In these figures, reference numeral 10 denotes a first rotating shaft, and an angular ball bearing 30 according to the structure of the invention is interposed between this first rotating shaft 10 and a housing 20 that covers the outer periphery thereof.

That is, the inner ring 31 of the angular contact ball bearing 30 is connected to the first rotating shaft 1
0 and the outer ring 32 of the angular contact ball bearing 30 are fixed to the housing 20, respectively.

A plurality of spherical rolling elements 33 are interposed in pressure contact between the inner ring 31 and the outer ring 32 of the angular contact ball bearing 30, and are held in a circumferentially equidistant state between the inner ring 31 and the outer ring 32 by a cage 34. There is.

The retainer 34 has an annular protruding piece 34a (transmission member in the structure of the invention) that protrudes in the axial direction on the back surface 32a side of the outer ring 32, and this protruding piece 34a
0 and is fixed to the shaft end of a second rotating shaft 40 coaxially arranged with the second rotating shaft 40 .

The second rotating shaft 40 connects the outer periphery of the protruding piece 34a and the housing 2.
0 and is supported by another angular ball bearing 50 installed between the two. Note that another angular contact ball bearing 50 is
It is not related to the gist of the invention, and other types of rolling bearings may be used.

This other angular contact ball bearing 50 and angular contact ball bearing 30
means the back surface 32a, 52a of each outer ring 32.52.
are arranged to face each other at a predetermined interval, and a preload spring 60, which is a resilient member, is interposed in the gap.

This preload spring 60 adjusts the axial clearance of the angular ball bearing 3o and the other angular ball bearing 50, and includes the back surface 32a of the outer ring 32.52 of the angular ball bearing 3o and the other angular ball bearing 50,
In this embodiment, eight preload springs 60 are used, and one end of each preload spring 60 presses eight points in the circumferential direction of the back surface 32a of the outer ring 32, and the other end Eight circumferential locations on the back surface 52a of the outer ring 52 are biased equally.

Of course, the axial clearance of the angular contact ball bearing 30 can be adjusted by adjusting the spring constant and quantity of the preload spring 60, so the pressing force of the rolling elements 33 against the inner ring 31 and the outer ring 32 can be set arbitrarily.

Note that the reference numeral 70 is a rolling bearing that supports the first rotating shaft 10, and the reference numeral 71 is a rolling bearing that supports the second rotating shaft 40.

Next, the operation will be explained.

When the second rotating shaft 40 is used as the input shaft and the first rotating shaft 10 is used as the output shaft, when the second rotating shaft 40 and the retainer 34 rotate, the retainer 34 rotates the rolling elements 33, and the rolling elements 33 and 33 rotate. Power is transmitted to the inner ring 31 and the first rotating shaft 10 that are in pressure contact, and the rotational speed of the second rotating shaft 40 is increased and transmitted to the first rotating shaft 10. At this time, since the rolling elements 33 are spherical and non-directional, a phenomenon called skew does not occur, and loss torque in power transmission is therefore minimized.

Conversely, if the first rotating shaft 10 is used as the input shaft and the second rotating shaft 40 is used as the output shaft, the rotation speed of the first rotating shaft 10 is reduced and the second rotating shaft 40 is used as the output shaft.
It is transmitted to the rotating shaft 40.

In addition, since the rolling elements 33 of the angular contact ball bearing 30 are spherical and solid, the strength against the thrust loads from the first rotating ring 10 and the second rotating shaft 40 can be ensured.

In addition, in the above embodiment, the retainer 34 has the protruding pieces 34a.
This protruding piece 34a is a second rotating shaft.

40, the present invention is not limited thereto, and for example, the three parts of the protruding piece 34a, the retainer 34, and the second rotating shaft 40 may be formed integrally. Further, the retainer 34 and the protruding piece 34a are constructed separately, and a transmission member such as the protruding piece 34a is directly connected to the second rotation shaft 40, and this transmitting member and the retainer 34 are connected. The present invention also includes configurations.

Furthermore, in all the bearings described in the above embodiments, the rolling elements can be made of ceramics.
Compared to the case of using rolling elements made of steel, it is possible to reduce the incidence of seizing or cracking due to collision of the rolling elements in the pocket portion (not shown) of the cage, especially at high speed rotation.

<Effect of the invention> According to the present invention, the following effects are exhibited.

Since the axial clearance of the angular ball bearing is kept constant by the resilient member, the predetermined pressure contact force required for power transmission can be stabilized.

In addition, angular contact ball bearings are used in the speed reduction section or speed increase section, and the rolling elements are spherical and non-directional, which prevents the phenomenon called skew from occurring, resulting in a reduction in torque loss. Can be done.

Furthermore, since the rolling elements are spherical and solid and have excellent rigidity, the risk of breakage that occurs with conventional hollow planetary rollers can be reduced. The strength against the thrust load of the two rotating shafts can be ensured.

As described above, it is possible to provide a highly reliable power transmission device that can achieve stable power transmission.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 show one embodiment of the present invention;
The figure is a longitudinal sectional view showing the power transmission device, and Figure 2 is the same as Figure 1.
It is a sectional view taken along the line -■. Further, FIGS. 3 to 5 relate to the conventional example, FIG. 3 is a longitudinal sectional view showing the power transmission device, and FIG.
FIG. 5, a sectional view taken along the line IV, is an explanatory diagram showing the skew phenomenon. 10... First rotating shaft 20... Housing 30... Angular contact ball bearing 31... Inner ring 32... Outer ring 32a... Back surface of outer ring 33... Rolling elements 34... Cage 34a ... Projection piece (transmission member) 40 ... Second rotating shaft 60 ... Preload spring (resilient member).

Claims (2)

[Claims] (1) Decreasing or speeding up the power between the first rotating shaft and a second rotating shaft that is interposed between the first rotating shaft and a housing that covers the outer periphery of the first rotating shaft and is coaxial therewith. a transmission member that connects the second rotating shaft to a cage that holds a plurality of rolling elements interposed in pressure contact between an inner ring and an outer ring of the angular ball bearing; A power transmission device comprising: an elastic member that applies preload to the angular ball bearing by urging the back surface of the outer ring. (2) The power transmission device according to claim (1), wherein the retainer and the transmission member are integrally formed.