JPS62279290A - Bearing structure of outer shaft type rotary piston flower - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

3. Detailed Description of the Invention The invention relates to a gaseous medium having a casing consisting of a jacket running track and two side parts and forming a working chamber with a piston rotating therein. This invention relates to a bearing device for an external rotary piston blower. The shaft of this piston has a ball bearing with a seal washer sealing the gas pressure in the working chamber, and also has the gear wheel of the transmission outside this bearing.

This type of blower can be of Roots blower or half-roll or quarter-roll construction, with two identical, cam actuators rotating in opposite directions with a 1:1 tooth ratio. It can be equipped with a piston. These blowers, especially as blowers for internal combustion engines, use air as the working medium.

In machines of this type, which, for economic reasons, must have a simple and "cheapest construction with mass production," the working chambers are connected to each other only by leak-tight gaps and also by passing through the lateral parts of the casing. The load in the working chamber, which changes due to overpressure and underpressure, causes pulsations in the working medium, and the ball bearings are exposed to the impact of the rapidly changing fluid. If overpressure exists in the gap space connecting the bearings, the packing washers of the respective ball bearings close. However, if overpressure exists in the cover space housing the gear transmission due to incomplete sealing of the bearings, the seal washer closes. occurs, which opens the seal washer of the ball bearing in the direction of the working space in the suction cycle, and in that case it is unavoidable to push this gear oil into this working space.This causes the gear oil to flow uncontrolled. Not only is it lost as is, but it also reaches the working medium, which should be oil-free.

If there is a negative pressure in the working chamber or in the gap connecting it to the ball bearing, the packing washer will similarly be pulled up, in which case essentially the bearing oil will be sucked out of the continuously lubricated ball bearing. As a result, the bearings fail very quickly.

In this case, it is important to note that gear oil is absorbed only when negative pressure is generated on the side of the bearing facing the working space; on the other hand, if there is overpressure in the cover space, the ball bearing The problem is that the oil that has been extracted may interfere with this suction. Therefore, measures to prevent the generation of this type of negative pressure on the working space side of the ball bearing are not sufficient. On the other hand, it is also not sufficient to arrange an overpressure valve in the cover space.

This is because the oil circulating in the ball bearing is already pressed down by the ball bearing before the overpressure valve responds.

The object of the invention is to avoid pressure pulsations of the working medium that affect the ball bearings, in particular the passage of transmission oil through the ball bearings as a result of overpressure in the transmission space as well as the side of the working space of the ball bearings. The purpose is to avoid absorbing oil and fat from the ball bearing due to negative pressure.

These objects are achieved in the case of the blower mentioned at the outset by the features described in the patent claims.

Embodiments of the present invention will be described in detail with reference to the drawings as follows.

In FIG. 1, the caning 1 of the blower consists of a jacket part 2 with cooling fins and a jacket running track 3. In FIG. The jacket track consists of two cylinders that penetrate in the intake region and the exhaust region. The jacket part 2 is closed on its sides by two side parts 4, only the gear side of which is shown. The casing has two shafts 5 and 6 rotating in ball bearings 7 and 8 arranged in the lateral parts.
penetrates in the axial direction. These shafts rotate with minimal clearance in bores 11 and 12 in the side parts and have shaft end plates 9 and 1 to which pistons 13 and 14 are screwed.
It has 0 on both ends. These pistons are mutually identical and radially symmetrical. Piston 13 is cut in the plane of its short radial axis, and piston 14 is cut in the plane of its long radial axis. Ball bearings are 15
A ball bearings 7 and 8 are installed in the space 18 in the casing cover 19 when there is overpressure in the working chamber 17. Close the leakage path through.

Shaft ends 20 and 21 formed by shaft end plates 9 and 10
Gears 22 and 23 having a gear ratio of 1:1 are keyed on the outside of the bearing.

Boring parts 11 and 1 are provided in the space 18 in the casing cover.
When an overpressure is created against the suction chamber by the pulsating impulses of the actuating means by the two gap seals and the bearing packings 15 and 16, the oil moving around the gears of the transmission will flow through the bearings and the subsequent opening of the bearings. It is pressed through the seal washers 15 and 16 into the above-mentioned interstitial space and into the working space 17 which is in each case during the suction stroke.

To avoid this, the bearing 8 is opened radially outwards around the bearing neck 24, as shown for the shaft end 21 in FIG. An annular gap 25 is provided. The oil that reaches this point flows downward around the bearing 8. The transmission-side wall 26 of the annular groove 25 prevents radial flow in such a way that it, together with the inner edge 27 of the tooth crown of the gear wheel 23 , forms a narrow annular space 28 that prevents the flow of oil in the direction of the axis 6 . Narrow annular space 28
It is pulled up radially outward to form a .

A second annular gap 29 of this kind is formed between the boss 30 of the gear 23 and the shaft hole of the bearing neck 24, and the annular space contained between these annular gaps 28 and 29 is
It serves as a buffer space for pulsating impacts of the working medium.

In order to avoid the generation of negative pressure in the gap space between the bores 11 and 12 and the side parts 4 and the bearing packings 15 and 16, it is necessary to On the side facing towards the side part 4 an annular space 32 is provided, which space defines the gap between the side part 4 and the bearing 8 as well as between the side part 4 and the shaft end plate 10. Together with the space, it is connected with a passage 33 opened in the side part 4. Furthermore, at the highest point of the side part 4 a bore 34 is provided, which opens into the annular space 32 in the shaft end plate 9 and at the outer end of which a check valve 35 is arranged, which opens into the annular space 32. 32 and the interstitial space connected thereto opens when there is a negative pressure.

By means of this valve, the negative pressure that develops inside the ball bearing is balanced and this prevents the suction of bearing oil, while the annular gap in the bearing neck and transmission gear is reduced by the cover space 1.
If there is overpressure in the annular groove 25, oil is prevented from entering unless it has flowed out from the annular groove 25.

[Brief explanation of drawings]

FIG. 1 shows an axial sectional view of the transmission side of the 1/4 inch blower, and FIG. 2 is an enlarged view of a part of FIG. 1. FIG. Description of symbols 1 Casing 2 Jacket part 3 Jacket running track 4 Side part 5.6 Shaft 7.8 Ball bearing 9.10 Shaft end plate for 5 and 6 11.12 Boring in 4 13.14 Piston 15.16 Packing washer 17 Space 19 in the working chamber 1819 Casing cover 20, 21 Shaft end 22) 23 Gear 24 Bearing neck 25 Annular gap 2924 between the inner edges 2826 and 27 of the crown of the transmission side wall 2723 of the annular groove 2625 Hole 35 for passage 3435 in annular space 3332 in annular space 32 9 between boss 3128 and 29 of annular gap 3023 between and 30 Check valve

Claims (1)

Claims: 1) Bearing of an external rotary piston blower for gaseous media with a casing consisting of a jacket running track and two lateral parts and forming a working chamber with a piston rotating inside. of the pistons (13, 14) in a bearing construction in which the axes of these pistons have ball bearings with packing washers for sealing off the gas pressure in the working chamber and a transmission gear on the outside of this bearing. An annular groove (25) directed outwards is provided around the bearing neck (24) of the ball bearings (7, 8) of the shaft (5, 6), the groove wall (26) of which on the transmission side gears (22, 23)
A bearing structure characterized in that it forms an annular gap (28) of very narrow tolerance with the inner edge (27) of the crown of the tooth. 2) In the bearing structure according to claim 1), between the hole for the shaft (5, 6) in the bearing neck (24) and the boss (30) of the gear (22, 23) of the transmission The bearing structure is provided with another annular gap (29). 3) In the bearing structure according to claim 1) or 2), the groove wall (26) on the transmission side and the gear (
22, 23) and the inner edge (27) of the crown of the tooth (22, 23), as well as the bearing neck (24) and the gear of the transmission (
22, 23) and the boss (30).
9) Bearing structure having a width of 1/10 mm to 1/20 mm. 4) In the bearing structure according to claim 2) or 3), the shaft end plate (9) of the shaft (5) is provided with an annular space on the side facing the lateral part (4), and this The annular space connects on the one hand via a passageway (33) with the interstitial space between the other shaft end plate (10) of the shaft (6) and the adjoining lateral part (4), and on the other hand the lateral part (4) A bearing structure connected to a check valve (35) via a hole (31) within.