RU2529943C1 - Coaxial reduction gear - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: coaxial reduction gear consists of driving cam shaft (5), crown gear, output shaft. Crown gear has double wheel (2). Coaxial to cam shaft gear (1) is connected with body and conjugated with crown (2) of double wheel from the side of driving cam shaft. Gear clutch providing coaxiality of driving cam shaft (5) and output shaft is connected with output shaft and conjugated with crown(3) of double wheel from the side of output shaft. Pitch surfaces (planes) of crown gears (2, 3) of double wheel are located along its axis at a distance providing coincidence of gear clutch pitch cone vertex with point of intersection of cam shaft axis and coaxial reducing gear axis. Module and number of teeth of gear clutch are taken to be equal, greater or less than module and number of teeth of crown gear.

EFFECT: invention provides high loading capacity, durability and makes possible to considerably lower required engine power without decreasing torque output shaft of reduction gear.

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Description

The invention relates to drive reduction mechanisms, in particular to installations of borehole screw pumps for lifting highly viscous formation fluids from wells in the oil industry, as well as in drives of various industries, made according to the pine scheme.

A planetary precession gear is known, comprising a housing, an input shaft mounted at an angle to its axis, a crank located on the last satellite and a central wheel, characterized in that the gear is equipped with at least one additional crank offset from the main by an angle of 2π / n , where n is the number of cranks, additional satellites, the number of which is equal to the number of additional cranks, and each satellite has a pair of circumferential windows with pins installed in them along the precession axis, and the teeth of the central o wheels are made in the form of rollers whose axes are parallel to the transmission axis (US Pat. No. 2029169, F16H 1/32).

The disadvantage of this transmission is the complexity of its manufacture in limited radial dimensions, insufficient durability due to the inevitable uneven load distribution between the satellites, and increased dynamic loads on the teeth that occur at the time of engine starting, due to the existing gaps in the engagement of the teeth of the satellites.

Known precession transmission, comprising a housing with a hole, housed in it coaxially inlet with an oblique crank and output shafts, a drive gear mounted on an oblique crank by means of a bearing and braked from rotation of the transmission housing, and a driven wheel associated with the output shaft, characterized in that, in order to increase the load capacity, the gears are cylindrical, one with internal teeth, the other with external teeth, and the driven wheel is connected to the output shaft by a universal joint (pa t. No. 2099614, F16H 1/32).

The disadvantage of this transmission is the presence of lateral clearances in the gearing, which lead to additional dynamic loads in the gearing of the teeth at the time of starting the engine, as well as the impossibility of its use in the installation of borehole screw pumps due to significant axial forces arising from the operation of the screw pump, which are not perceived by the cylindrical gear, and perceived only by radial bearings. The presence of a universal joint greatly complicates the design.

Known precessional gear transmission (patent No. 2025617, F16H 1/32), designed for use in various gearboxes, containing two engaging bevel wheels with internal and external teeth, respectively, characterized in that the teeth of both wheels are made with a cycloidal profile, the angle of which is on the initial the circle is equal to half the angle of the precession. The disadvantage of this transmission is the high complexity of making a bevel wheel with internal teeth (the existing gear cutting equipment for cutting such wheels is not intended), especially when the wheels must have high hardness and require the use of finishing operations to ensure the necessary contact strength. The presence of lateral clearances in the gearing of the wheels at starting moments of the engine leads to additional dynamic loads in the gearing of the teeth and their premature failure.

Closest to the proposed solution is a reducing module (US Pat. RU 2334125 C1, F04C 2/107, F04B 47/02, publ. 09/20/08, bull. No. 26), consisting (figure 1) of the housing 1, the drive eccentric shaft 2, of the gearbox, of the output shaft 3, wherein the gearbox is double-crowned 4, the gear 5 coaxial to the eccentric shaft is connected to the housing and mated with the crown of the double-gear wheel on the side of the drive eccentric shaft, and the gear clutch 6, ensuring alignment of the drive eccentric shaft and output shaft 3, connect nene with the output shaft and is paired with the rim of the two-gear wheel on the side of the output shaft, and the two-gear wheel 4 is rigidly fixed relative to the eccentric shaft 2 (Fig.1, pos.1-6).

This reducing module allows the reduction of the pump shaft speed within a wide range (with a gear ratio of 6 to 100), however, the execution of the gear rims of the double-wheel gear 4 at an arbitrary distance along its axis leads to an additional load of gearing of the gear teeth, which limits the service life of the coaxial gearbox as a whole. This circumstance is a consequence of the fact that for an arbitrary distance between the gear rims of the wheel 4, the gearbox essentially becomes a two-row planetary gear with spatial gearing of the teeth in two spaced gearing zones.

The objective of the invention is the provision of working conditions of the gear coupling of the coaxial gearbox, in which the planetary movement of its links is eliminated, which reduces the uneven distribution of the load in the zones of engagement of its teeth and thereby increases the efficiency of the coaxial gearbox containing a flat gear, and reduces the risk of destruction of the teeth of the gear wheels in engine start time.

EFFECT: increased working capacity and resource of a bevel gear and gear coupling of a coaxial gearbox.

The specified technical result is achieved by the fact that for the most loaded gearing of the coaxial gearbox - the gear clutch, which is a flat bevel gear with a gear ratio equal to one made up of wheels 6 and 4 (figure 1), the corresponding choice of the spacing of the gears of the wheel 4 provides the condition its work is not as planetary, but as a linear gear, in which there are no additional dynamic loads caused by the planetary movement of the links, and the module and the number of teeth of the wheels 6 and 4 are gear second clutch take equal, greater or less than the module and the number of pan-gearwheel transmission, consisting of the wheels 5 and 4.

Figure 2 shows the design scheme of the proposed coaxial gearbox with precessing flat-bevel gear: gear 1 with a conical initial surface; a wheel 2 having two gears 2 and 3 spaced apart by a value B, the initial surfaces of which are a plane; movable gear 4 with a tapered initial surface; carrier 5, having an eccentric shaft portion located at an angle ∑ to the common axis of the O-O coaxial gearbox.

During operation of the coaxial gear, the gear 1 is stationary, the wheel 2 makes a complex movement - rotation around its axis and together with the carrier 5 around the O-O axis. The vertices of the initial cone of gear 1 and the initial cone of the ring gear 2 (cone angle 90 °) do not match. To exclude the planetary movement of the links in the most loaded (low-speed) flat conical gear (gear clutch) composed of wheels with gears 3 and 4, it is necessary that the top of the initial cone of the gear 4, the top of the initial cone of the gear 3 (cone angle 90 °) not only coincided, but also were at the point of intersection of the axis of the eccentric shaft section and the axis of the OO coaxial gearbox. The fulfillment of this condition corresponds to only one value of the value B, calculated from the dependence:

, $$B=\frac{{\mathrm{<figure-callout\; id="2"\; label="m\; n"\; filenames="00000005.png"\; state="\{\{state\}\}">m\; </figure-callout>}}_n}{2\cdot \cos \beta }\left(\frac{z_2}{tg\Sigma }-\frac{z_{\mathrm{one}}}{\sin \Sigma }\right)$$

,

where m _n is the normal module of the flat-bevel gear; β is the angle of inclination of the tooth line; z ₁ is the number of gear teeth 1; z ₂ - the number of teeth of the wheel 2 (ring gear 2); ∑ is the angle of precession.

Toothed clutch - a flat-bevel gear of a coaxial gearbox made up of wheels with gears 3 and 4, in accordance with the prototype, is made with the number of teeth z ₃ = z ₄ and has a gear ratio equal to one. This gear in the gearbox is slow and therefore the most loaded. To increase its load-bearing capacity and service life, the normal module of this transmission is proposed to be taken equal to, greater or less than the module m _n for precessing flat-bevel gears with gears 1 and 2, az ₃ = z ₄ to be taken equal to, greater or less than z ₂ (figure 3). The equality of the modules and z ₃ = z ₄ = z ₂ provides the minimum radial dimensions of the coaxial gearbox.

A coaxial gearbox is installed between the electric motor and the drive shaft, for example, a rotor of a screw pump for the extraction of heavy oils.

When the motor is turned on, the rotation is transmitted to the drive eccentric shaft of the coaxial gearbox rotating with a frequency of n ₁ . The wheel with gears 2 and 3 performs a complex movement - rotation around its axis and together with the drive eccentric shaft 5 around the OO axis, causing the rotation of the bevel gear with gears 3 and 4 (gear coupling). In this case, two pairs of engagement zones z ₁ -z ₂ and z ₃ -z _{4 of} plano-conical gear rims oppositely located at an angle of 180 ° are formed. The rotation from the gear coupling, the wheel of which with the ring gear 4 is made integral with the output shaft rotating with a frequency of n ₂ , is transmitted to the rotor of the screw pump.

The total gear ratio of the coaxial gearbox is implemented by a pair of gear rims z ₁ and z ₂ and is determined by the following formula:

, $$u=\frac{z_2}{z_2-z_{\mathrm{one}}}$$

,

where z ₁ is the number of gear teeth 1; z ₂ - the number of teeth of the ring gear 2 of a two-crown wheel.

The range of possible gear ratios of the reducing module is wide. For example, when the values of the number of teeth: z ₁ = 19; z ₂ = 20; z ₃ = 20; z ₄ = 20, and the use of an electric motor in a pump installation with a rotation speed of 2950 rpm, the rotational speed of the rotor of the screw pump will be 147.5 rpm. Such rotor speeds allow the use of a screw pump for lifting highly viscous formation fluids with a high concentration of sand and a percentage of free gas. With the module m _n = 3 mm, the radial dimensions of the coaxial gearbox correspond to the radial dimensions of the pump for oil production (outer diameter 92 mm), while the value of B for Σ = 3 ° has a value of B = 27.587 mm, which is quite enough for the design of the double-crown wheel.

Thus, the proposed technical solution will reduce the rotational speed of the rotor of a submersible screw pump for lifting highly viscous formation fluids from wells while ensuring high loading capacity of the drive part of the installation, as well as significantly reduce the required motor power without reducing the torque transmitted to the rotor of the screw pump. Therefore, it provides a technical effect and can be carried out using means known in the art, i.e. has industrial applicability. Additionally, the proposed coaxial gearbox can be used in drives for which, at high gear ratios, it is necessary to provide high load capacity and durability, for example, in valves of shutoff valves, winches of drilling rigs, drives of transport equipment (wheel and / or final gearboxes of tractors, excavators, fire fighting robots and etc.).

Claims (1)

A coaxial gearbox consisting of a housing, a drive eccentric shaft, a gearbox, an output shaft, the gearbox wheel being two-gear, a gear coaxial with the cam shaft connected to the housing and mating with the crown of the gear wheel from the drive cam shaft, and a gear clutch providing the alignment of the drive eccentric shaft and the output shaft, connected to the output shaft and mated to the rim of the two-crown wheel on the output shaft side, characterized in that tially surface (plane) toothings dvuhventsovogo wheel located along the axis at a distance that ensures the coincidence vertices primary gear coupling cone with the point of intersection of the axis of the eccentric shaft and the axis of the coaxial gear, depending on the distance:

,
where m _n is the normal module of the flat-bevel gear; β is the angle of inclination of the tooth line of the bevel gear; z ₁ , z ₂ - the number of gear teeth and gears; ∑ is the angle of precession, while the module and the number of teeth of the gear coupling are taken to be equal to, greater than or less than the module and the number of teeth of the gear wheel.

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